• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.245-252
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• 1993

To investigate a simple and rapid screening method for photosynthetic inhibitory herbicides, responses of tobacco(Nicotiana tabacum L.) and liverwort(Marchantia polymorpha L.) PA(photoautotrophic) cells to various commercial herbicides with different modes of action and leaf extracts of four weed species were compared. PET (photosynthetic electron transport) inhibitory type of herbicides has greater inhibitory effect in liverwort photoautotrophic cells than the photomixotrophic and heterotrophic cultured cells. Similary, PET inhibitory type of herbicides inhibited the oxygen evolution more in liverwort PA cells than the other type of herbicides. Based on oxygen evolution, 60% inhibition was observed by the 10% aqueous extracts of Polygonum hydropiper, while there was 100% inhibition by the 10% methanol extracts of Polygonum hydropiper. This assay gave well correlated results to the Hill reaction data using isolated thylakoids. Thus liverwort photoautotrophic cells might be suitable materials for rapid screening method for photosynthetic inhibitory herbicides.

• Resources Recycling
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• v.31 no.5
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• pp.34-41
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• 2022

Smelting reduction of spent lithium-ion batteries results in metallic alloys, slag, and dust containing Li(I). Precipitation of Li₂CO₃ was performed using the synthetic leachate of the dust. Herein, the effects of the precipitant and addition of non-aqueous solvents on the precipitation of Li(I) were investigated. Na₂CO₃ was a more effective precipitating agent than (NH₄)₂CO₃ owing to the hydrolysis reaction of dissolved ammonium and carbonate. The addition of acetone or ethanol improved the Li(I) precipitation percentage for both the precipitants. When using (NH₄)₂CO₃, the Li(I) precipitation percentage increased at a solution pH of 12. Under the same conditions, the Li(I) precipitation percentage using Na₂CO₃ was much higher than that using (NH₄)₂CO₃.

• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.311-322
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• 2015

The study was conducted on growth and yield of potatoes in a wick hydroponic culture as affected by concentration of aqueous extracts in order to develop natural agricultural resources using Persicaria longiseta. Each 500 ml of distilled water (control) and P. blumei extracts (25%, 50%, 75%, and 100%) was applied to potato plants at 5 d intervals from 1 d after potato transplanting. The potatoes with P. blumei extract emerged 1 d earlier and had 0.3 to 0.4 more stem numbers per plant compared with those of control plot. The plant height was higher in plots with P. blumei extract than in control in early stage of potatoes (50 d), but there was no significant difference observed after mid-stage of potatoes (70 and 90 d). The stem diameter and fresh weight of potatoes estimated a higher values in plots with P. blumei extract than in control plots, although there was no statistical difference. The 100% P. blumei extract increased by up to $13.8kg/m^2$ of potato yield. The numbers of tubers in classes of < 5 g and 5 to 30 g per plant did not show a specific trend among experimental treatments while it in class of > 30 g was much higher in plots with P. blumei extract than in control plot. Accordingly, the P. blumei extract had a positive effect on the growth and yield of potatoes, could be applied as of eco-friendly fertilizers

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.61-66
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• 2020

Recently, a variety of electric anesthetics devices have been developed and used in clinical practice to reduce the fatigue of the operator during local anesthesia for dental procedures and to compensate for the disadvantages of manual anesthesia device. In this electric anesthesia injection device, the accurate and constant delivery of pressure for drug infusion is a very important performance factor. In order to evaluate the accuracy of the transfer pressure, a small pressure gauge using a load cell is often used, but since the elastic body inside the load cell may not be able to accommodate a sufficient displacement, an error may occur when evaluating pressure performance. For these reasons, in this study, we proposed and evaluated a silicon-chrome steel (Si-Cr steel) spring jig that can accommodate relatively large displacements that can be used when evaluating the performance of a pressure-controlled pressure application device using a load cell type pressure gauge. As a result of the pressure transmissibility test and repeated measurement results using a commercial dental anesthesia injection device, a more stable result was obtained when using a spring jig, and it was confirmed that the frequency of abnormally high measurement was reduced.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.24-29
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• 2014

The effects of Lycii fructus and Lycii folium on osteoporosis and serum cholesterol levels were tested in ovariectomized (OVX) rats. Twenty-four female Sprague-Dawley rats were divided into four groups: Sham group (sham-operated), Control group (OVX, ovariectomized model), LCF group (Ovx+Lycii fructus extract), and LCL group (OVX+Lycium folium extract). After 8 weeks, the OVX ($330{\pm}5.39$ g), LCF ($315{\pm}2.99$ g), and LCL ($318{\pm}2.06$ g) groups showed increased body weight compared with sham group ($281{\pm}1.71$ g). The levels of serum osteocalcin (OC) also increased in the LCF ($444.6{\pm}26.9$ ng/mL) and LCL ($407{\pm}18.9$ ng/mL) groups compared with the OVX group ($107{\pm}3.52$ ng/mL). The activities of serum alkaline phosphatase (ALP) increased in the LCF ($108{\pm}2.7$ U/L) and LCL ($407{\pm}18.9$ ng/mL) groups compared with the OVX group ($95{\pm}2.9$ U/L). Stereomicroscopy found that the low bone density that developed in the OVX group was significantly reversed in the LCF and LCL groups after 8 weeks. We also obtained molecular-based in vivo evidence that supports a mechanism of action involving novel estrogen receptor ($ER{\alpha}$) modulator in the uterus. We found that expression of ER${\alpha}$ mRNA in the OVX rat uterus was elevated by Lycium chinense. These results suggest that Lycii fructus and Lycii folium administered to rats during 8 weeks after oophorectomy may partially recover postmenopausal osteoporosis or delay the progression of osteoporotic changes.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.341-353
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• 1974

The electrochemical reduction of triphenylphosphine penylimide in nonaqueous media has been examined by polarography, cyclic voltammetry, controlled-potential coulometry and electron spin resonance spectroscopy. The reduction of triphenylphosphine phenylimide proceeds by a one-electron transfer to form anion radical which undergoes both protonation and a second one-electron reduction followed by cleavage of the phosphorus-nitrogen double bond. Aniline is a major product. The cleavage of a phosphorus-phenyl bond was also observed after reduction of triphenylphosphine oxide which is one of the major products of the chemical reaction which follow the primary process.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.93-93
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• 2008

니켈도금은 각종 소지 상에 직접적이고 밀착성이 양호하고, 변색이 적고 방청력이 크며, 경도, 내식성, 내마모성 및 유연성이 우수하다. 또한 최근 활발히 진행되고 있는 광촉매 연구에 $TiO_2$는 우수한 광화학적 안정성, 효과적인 전하분리, 높은 산화 환원력 및 상업적 적용성을 갖기 때문에 니켈도금용액에 $TiO_2$를 첨가하며 복합도금을 행함으로써 니켈이 가지고 있는 기존의 우수한 특성에 $TiO_2$의 광분해 효과를 부과시킴 으로써 그 특성이 한층 더 향상되는 것을 알수있다. 본 연구에서는 수용액전해질과 비수용액 전해질에서의 Ni-$TiO_2$ 복합도금의 특성을 비교 분석해보았다. 동전위(Potentiodynamic)실험 및 순환전위(Cyclic Voltammetry)실험을 하였으며, 도금층의 특성 및 두께는 OM,SEM을 이용하여 분석하였다. 또한 복합도금 촉매 전극에 의한 광분해 효과를 보기 위해서 UV램프를 이용하여 분석하였다.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.121-130
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• 1985

The phenolic compounds identified from rye and wheat residues seemed to be p-coumaric, p-hydroxybenzoic, vanillic, ferulic, salicylic and syringic acids. Total phenol content of rye and wheat straw determined at heading stage was 0.1803% and 0.1702%, respectively. Total phenol content in straw was higher than that of root at all growth stages. The germination and growth of plants, such as Oryza sativa, Echinochloa creugalli, Cyperus serotinus, Portulaca oleacea, Amaranthus retroflexus, Digitaria saguinalis, and C. album were inhibited by treatments of authentic phenolic compounds as the concentrations increased. However, at the early stage, the germination and shoot growth of P. distinctus were markedly stimulated by them, and then the further growth of shoot and root was markedly inhibited by the prolonged treatment of phenolic compounds. The aqueous extracts from rye and wheat straw completely inhibited the germination of A. retroflexus and C. album at a high concentrations. The content of starch and protein in bulbs of P. distinctus was lower in the p-hydroxybenzoic acid treated plot, at $10^{-2}M$, than the untreated control.

• Environmental and Resource Economics Review
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• v.32 no.3
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• pp.191-215
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• 2023

This study focuses on evaluating and comparing residents' acceptance of unutilized heat such as hydrothermal energy and waste heat from waste incineration and data centers in the case that they are used as district heat sources. This is because securing residents' acceptance is significantly important in order for unutilized heat to be considered as a heat source of district heating and cooling to achieve neutrality in the heating and cooling sector. A survey of heating consumers' perception on unutilized heat energy is conducted and a conjoint model is used to analyze the willingness to pay of heating consumers on incineration heat, water heat, and data center waste heat and to compare them with existing gas heat sources. As a result of the analysis, it is confirmed that district heating using hydrothermal energy and data center waste heat is preferred to district heating from heat from a natural gas plant or waste incineration.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.314-322
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• 2004

The production of a glucan was affected by the concentration of ions and buffer solutions, and nutrients in an oral cavity. In this study, the effects of ions and buffer solutions on the mRNA expression of gtfD gene in Streptococcus mutans, an important causative agent of dental caries, were investigated by Fluorescent in situ hybridization(FISH). At first, ions and buffer solutions had little effect on the multiplication of Streptococcus mutans. The green fluorescence according to the mRNA expression of gtfD gene was detected in the BHI broth containing 1% sucrose. The intensities of the green fluorescence were strong at 0.25mM of $CaCl_2$. Little fluorescence was detected by the addition of KCl, except far 10mM KCl at which fluorescence intensities were similar to those of the control. Fluorescence intensities were weak at each concentration of $MgCl_2$ when compared to the control. As for buffer solutions, fluorescence intensities were similar to those of the control at each concentration of buffer solutions, except that they were little detected at 100mM of potassium phosphate.