• Korean Journal of Soil Science and Fertilizer
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• v.48 no.1
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• pp.22-29
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• 2015

The objectives of this study were to monitor the changes in soil solution nutrients and to evaluate their effect on rice uptake and yield. The changes of chemical characteristics of paddy soil solution were examined from the 58th fertilization experiment in which the continuous rice cropping experiment started in 1954 at the National Academy of Agricultural Science. The treatments were no fertilization (No fert.), inorganic fertilization (NPK), inorganic fertilizer plus rice straw compost (NPKC) and inorganic fertilizer plus silicate and lime fertilizer as a soil amendment (NPKCLS). The fertilizers were added at rates of standard fertilizer application rate in which nitrogen (N), phosphate ($P_2O_5$), potassium ($K_2O$), and sililcate ($SiO_2$) were applied at rates of $75{\sim}150kg\;ha^{-1}$, $70{\sim}86kg\;ha^{-1}$, $75{\sim}86kg\;ha^{-1}$, and $7.5Mg\;ha^{-1}$ respectively and lime was applied to neutralize soil acidity until 6.5. Average Electrical Conductivity (EC) of soil solution in NPKCLS and NPKC ranged from 1.16 to $2.00dS\;m^{-1}$. The $NH{_4}^+$ and $K^+$ levels in NPKCLS and NPKC were higher than that of the other treatments, due to high supply power of rice straw compost. The content of $H_3SiO{_4}^-$ was higher in NPKCLS because of silicate application. The dominant ions in soil solution were $Ca^{2+}$, $Mg^{2+}$ and $Na^+$ among cations and $HCO{_3}^-$, $SO{_4}^{2-}$, and $Cl^-$ among anions in all treatments. The continuous application of inorganic fertilizers plus rice straw compost (NPKC) and silicate fertilizer (NPKCLS) led to the changes of various chemical composition in soil solutions. Also, they had a significant impact on the improvement of rice inorganic uptake and grain yield. Especially, inorganic uptake by rice in NPKC and NPKCLS significantly increased than those in NPK plot; 14~46% for T-N, 32~36% for P, 43~57% for K, and 45~77% for Si. Therefore, the combined application of inorganic fertilizers with organic compost as a soil amendment is considered as the best fertilization practice in the continuous rice cropping for the improvement of crop productivity and soil fertility.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1137-1143
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• 2011

Optimum soil management of chestnut orchards is important to ensure high quality and yields of chestnut. This study was conducted to evaluate soil and green leaf characteristics by establishment periods of chestnut (Castanea crenata Sieb. et. Zucc.) orchards in Sancheong-gun, Gyeongsangnam-do. Total 30 plots with the criteria of similar cultivation practices were chosen and classified into two establishment periods by over 20-year-old orchards (17 plots) and below 19-year-old orchards (13 plots). Soil bulk density was significantly higher (p<0.05) in over 20-year-old ($1.16g\;cm^{-3}$) than in below 19-year-old ($1.03g\;cm^{-3}$) plots. Soils in over 20-year-old plots were severely acidified with pH 4.56 compared to pH 4.73 in below 19-year-old plots. However, soil organic matter, total nitrogen, available phosphorus, and potassium were not significantly different (p>0.05) between both establishment periods. Leaf area, leaf mass, and nutrient (N, P, K, Ca, Mg) concentration of green leaves were also not significantly different (p>0.05) between both establishment periods. The results indicate that soil bulk density in chestnut orchards is dependent on the establishment periods, while soil chemical property and leaf nutrient concentration may be little influenced by the establishment periods.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.291-300
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• 2018

Background: The use of a functionally closed system for the glycerolization and deglycerolization of red blood cells (RBCs) allows for prolonged post-thaw storage for more than 24 hours. The aim of this study was to assess glycerolization and deglycerolization processing for RBCs using a high glycerol method in the automated, closed system provided by Haemonetics ACP 215. Methods: Thirty-five packed RBCs were glycerolized using the ACP 215 to a final concentration of 40% (wt/vol). The units were either frozen as such (n=30) or excess glycerol was removed (n=5) before freezing. After storage at $-80^{\circ}C$, the units were thawed, deglycerolized and resuspended in SAG-M. The frozen-thawed RBCs were stored at $4^{\circ}C$, and analyzed for their stability and in vitro quality. Results: No prefreeze excess glycerol removal units showed significantly less potassium leakage during post-thaw storage compared to the prefreeze excess glycerol removal units. All measurements of the stability and in vitro quality of thawed RBCs prepared from frozen RBCs without the prefreeze removal of excess glycerol during post-thaw storage at $4^{\circ}C$ for 7 days were acceptable to the American Blood Bank Association's standards and European standards. Conclusion: RBCs frozen without prefreeze removal of excess glycerol and the ACP 215 simplifies cryopreservation procedure and increases the stability of frozen-thawed RBCs. This increases the practical applicability of cryopreserved RBCs in blood transfusion practice.

• Journal of the Korea Institute of Building Construction
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• v.19 no.4
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• pp.289-297
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• 2019

Epoxy resin adhesives are currently used as adhesives in buildings. Epoxy resin adhesives, which are organic materials, generate harmful substances when producing adhesives, and toxic substances are high in the residential space after installation. In addition, a large amount of carbon monoxide generated from organic materials in the case of a building fire leads to personal injury. This study evaluates the feasibility of inorganic adhesives using pure inorganic materials such as magnesia, phosphate, and borax as inorganic adhesives to replace existing organic adhesives. As a result of the experiment on the selection of adequate phosphate and the characteristics of the addition rate of borax used as a retarder, the potassium phosphate monobasic was obtained as a suitable phosphate and the characteristics according to the borax addition rate were compared with the quality standard of KS F 4923 The hardening shrinkage and heat change rate satisfied the quality standards. The tensile strength was satisfactory when the borax addition rate was 4% or more, but the adhesive strength did not meet the quality standards. Further studies are needed to improve adhesion strength.

• Korean Journal of Materials Research
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• v.29 no.4
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• pp.205-210
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• 2019

$Pb(Zr,Ti)O_3$ (PZT) is used for the various piezoelectric devices owing to its high piezoelectric properties. However, lead (Pb), which is contained in PZT, causes various environment contaminations. $(K,Na)NbO_3$ (NKN) is the most well-known candidate for a lead-free composition to replace PZT. A single crystal has excellent piezoelectric-properties and its properties can be changed by changing the orientation direction. It is hard to fabricate a NKN single crystal due to the sodium and potassium. Thus, $(Na,K)NbO_3-Ba(Cu,Nb)O_3$ (NKN-BCuN) is chosen to fabricate the single crystal with relative ease. NKN-BCuN pellets consist of two parts, yellow single crystals and gray poly-crystals that contain copper. The area that has a large amount of copper particles may melt at low temperature but not the other areas. The liquid phase may be responsible for the abnormal grain growth in NKN-BCuN ceramics. The dielectric constant and tan ${\delta}$ are measured to be 684 and 0.036 at 1 kHz in NKN-BCuN, respectively. The coercive field and remnant polarization are 14 kV/cm and $20{\mu}C/cm^2$.

• Journal of Life Science
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• v.30 no.12
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• pp.1085-1091
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• 2020

The purpose of this study was to investigate the value of residue discarded after harvesting a species of pepper (Capsicum annuum L.). This study analyzed the physiological activity and cytotoxicity of a fermented extract and a hot water extract gathered from the residues of the Cheongyang pepper and the Nokkwang pepper. The total nitrogen, phosphoric acid, potassium, calcium, and magnesium contents of the fermented extract of the Nokkwang pepper were approximately twice as high as those of the Cheongyang pepper, while the hot water extracts had similar levels of these components across both peppers. Among the microelements, only boric acid, iron, and silicon components were detected, whereas zinc, manganese, molybdenum, and copper components were not detected in either extract. The total polyphenol and flavonoid contents of the fermented extracts were more than two times higher than those of the hot water extracts for both peppers. The DPPH radical scavenging ability (indicating antioxidant activity) of the fermented extract was higher than that of the hot water extract, while the ABTS radical scavenging ability (indicating antioxidant activity) of the hot water extract was higher than that of the fermented extract. A cytotoxicity test was conducted on the extracts using an MTT assay. Both extracts exhibited weak cytotoxicity at all concentrations for both peppers. These results suggest that the extract of residue discarded after harvesting these peppers could be suitable for functional feed or agricultural materials.

• Clean Technology
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• v.27 no.2
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• pp.132-138
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• 2021

Research is being conducted on graphene to provide graphene having both excellent physical as well as electrical properties in addition to unique physical properties. In this study, Hummer's method, which is a representative method for chemical exfoliation, was applied in order to investigate the possibility of the mass production of high-quality graphene oxide. Three types of graphite (graphite, crystalline graphite, and expanded graphite) were used in the preparation of graphene oxide with variations in the amount of potassium permanganate added, reaction temperature, and reaction time. Then a Fourier transform infrared spectroscopy (FT-IR), a Raman spectrometer, and a transmission electron microscope (TEM) were used to measure the quality of the prepared graphene oxide. Of the three types of graphite used in this experiment, crystalline graphite showed the highest quality. The prepared graphene oxide was then purified with an organic solvent, and an analysis conducted using energy dispersive X-ray spectroscopy (EDS). From the results of the residual values, we were able to confirm that both acid wastewater and wastewater were best purified using cyclohexane. The method for manufacturing graphene oxide as well as the method of purification using organic solvents that are presented in this study are expected to have less of an environmental impact, making them environmentally friendly. This makes them suitable for use in various industrial fields such as the film industry and for heat dissipation and as coating agents.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.751-759
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• 2022

Currently, ultrasound examination for diagnostic ultrasound and health examination purposes is widely used, and it is showing an increasing trend due to the application of health insurance. However, the risk of ultrasound has not been clearly identified so far, and in this study, surface and deep temperature changes according to frequency and mode were measured by using a tissue mimicking phantom and TI and MI values were compared. A simulated phantom was manufactured by adding a small amount of kappa-caraginan powder with acoustic characteristics similar to that of the human body and potassium chloride for solidification, and the change of surface and depth temperature was measured using a surface thermometer and a probe thermometer. As a result, the convex probe using low frequency showed a higher temperature increase than the linear probe using high frequency, so there was a significant difference, and the temperature increase was the highest on the surface, and the depth of 1cm showed a temporary temperature increase, but there was no significant temperature change. There was no change in the deep temperature of 5 cm to 15 cm, and the TI and MI values did not change during the test time. Since only the surface temperature rose during the 15-minute test and there was no temperature change in the core, so it is not expected to show a temperature change that is harmful to the human body. However, it is thought that prolonged examination of one area may cause temperature rise, so it should be avoided.

• The Korea Journal of Herbology
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• v.36 no.6
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• pp.27-37
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• 2021

Objectives : In the current study, we performed the 13-week repeated oral dose toxicity test and a 4-week recovery test of standardized Cornus officinalis Sieb. et Zucc. and Psoralea corylifolia L. 30 % ethanol extract (SCP) in Sprague-Dawley (SD) rats owing to aims for verifying no observed adverse effect level (NOAEL). Methods : The animal study was performed according to OECD guidelines for the testing of chemicals section 4 health effects test No.408 repeated dose 90-day oral toxicity study in rodents (03 October 2008). In the repeated dose toxicity study, SCP was orally administered to female and male rats at dose levels of 1,000, 2,000, and 4,000 mg/kg/day for 13-week. The control group and high dose (4,000 mg/kg/day) group were then monitored for 4 extra weeks to determine recovery time after the study period. 1) Results : Compared with the control group, there were no treatment-related adverse effects in clinical signs, body weight, hematology, serum biochemistry (Aspartate aminotransferase, Alanine aminotransferase, Alkaline phosphatase, 𝛾-Glutamyl transpeptidase, Blood urea nitrogen, Creatinine, Glucose, Total cholesterol, Total protein, Creatine phosphokinase, Albumin, Total bilirubin, Triglyceride, Inorganic phosphorus, Albumin/Globulin ratio, Calcium ion, Sodium ion, Potassium ion, Chloride ion), necropsy findings and organ weight (Ovary, Adrenal gland, Pituitary, Thymus, Prostate, Testis, Epididymis, Spleen, Kidney, Heart, Lung, Brain, Liver) at any dose tested. Conclusions : Taken together, these results suggest that the NOAEL of SCP in both genders was considered as over 4,000 mg/kg. Results from this study provide scientific evidence for the safety of SCP.

• Journal of Nutrition and Health
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• v.55 no.5
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• pp.558-571
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• 2022

Purpose: The purpose of this study was to analyze the dietary intake of Korean adults with atopic dermatitis (AD) to determine whether the risk of developing AD was related to their diet. Methods: Among the participants in the 7th National Health and Nutrition Survey (2016 to 2018), 10,571 adults aged 19-64 were divided into AD (AD group, n = 366) and control groups (non-AD group, n = 10,205) to compare and analyze their nutrient intake status and Korean Healthy Eating Index (KHEI) score. Depending on the prevalence of AD, the nutrient intake, nutrient intake per 1,000 kcal, acceptable macronutrient distribution range, and KHEI score were tested for significance by correcting for age, sex, body mass index, education, marriage, occupation, residence area, physical activity, and energy intake variables that were derived for confounding factors. Results: The acceptable macronutrient distribution range for protein was lower in the AD group than in the non-AD group. Comparing the nutrient intake per 1,000 kcal, the intakes of protein, phosphorus, iron, and potassium of the AD group were significantly lower than those of the non-AD group. In the KHEI, the scores of total vegetables, vegetables excluding kimchi and pickles, meat, fish, eggs, and legumes of the AD group were significantly lower than those of the non-AD group. In addition, as these food intake scores increased, the risk of AD significantly decreased. Conclusion: In conclusion, adult AD patients had low intakes of vegetables, meat, fish, eggs, and legumes, and it was confirmed that high intakes of these foods may be associated with low AD risk. Therefore, we suggest that an adequate intake of vegetables and foods containing protein would be necessary for the management and treatment of AD in adults.