• The Korean Journal of Ecology
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• v.26 no.6
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• pp.313-319
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• 2003

Dry weight loss and nutrient release from leaf litter for six tree species were studied using litter bag methods. The litter bags were incubated for f6 months on the forest floor in temperate deciduous forest in Mt. Cheonma, located at the middle part of Korean Peninsula. The changes in nutrient content and the rate of dry weight loss in leaf litter varied with litter types. The litter of Pinus densiflora showed the lowest rate of mass loss (k=0.33), nitrogen concentration (0.89%) and ash concentration (2.50%), while showed the highest C/N ratio (63.40). On the other hand, the litter of Acer pseudo-sieboldianum showed the fastest rate of mass loss (k=0.82), the highest nitrogen concentration (1.11%), and the lowest C/N ratio (49.40). During the decomposition, nitrogen, phosphorus and calcium in the leaf litters showed relatively slow decreasing pattern compared to other elements (carbon, potassium, magnesium, manganese and sodium), but potassium and sodium decreased at early stage of the decomposition for all leaf litters. Differences in annual decomposition rates of litter among species were consistent with the particular chemical characteristics of their leaf litters. The initial concentration of nitrogen was positively correlated with litter decomposition rate for six species, while litter decomposition rate of six species was negatively correlated with C:N ratio of initial leaf litters.

• Journal of Bio-Environment Control
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• v.11 no.3
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• pp.121-126
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• 2002

This study was conducted to investigate the effect of high concentration of sodium salts and chlorides in soil on the growth of tomato and the uptake of minerals. The growth inhibition rates of plant height and dry weight were different depending on salts, but they were not related to the electric conductivities (EC) and acidities (pH) in the soil solution. The orders of growth inhibition were Cl, SO$_4$, CO$_3$, PO$_4$＞NO$_3$ in the sodium salts series, and Na, K, Mg, NH$_4$＞Ca in the chlorides. The growth inhibition rates of the sodium salts series tended to be larger than those of the chloride series. Yield was lower 30%~10% in the sodium salt and chloride series than in the control. Chlorophyll content, photosynthetic rate and stomatal conductance were lower in the sodium salts and chloride series than in the control. Mineral concentration was lower in sodium salts and chlorides than in control. The nitrate absorption was inhibited in all salts except for NaNO$_3$ and NH$_4$Cl, and specially in NaCl and Na$_2$SO$_4$ treatments of the sodium salts and in KCl treatment of chloride series. K concentration was reduced NaCl and Na$_2$SO$_4$ treatments compared with the other salts. In the sodium salt series, calcium and magnesium concentration were decreased antagonistically when sodium concentration was increased.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.163-169
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• 1985

The composition rates of litters were studied at Camellia japonica forests in Koje-Do and Haenam, and at Quercus acuta, Quercus acutissima, Cryptomeria japonica, and Chamaecyparis abtusa forests in Haenam. Total amounts of nitrogen, phosphorus, potassium, calcium, and sodium in litter samples were measured and the relation between these amounts and decomposition rate was studied. Annual litter production were rarely different at each forest in Haenam. The amount of accumulated organic matter was about 4 times greater at C. japonica forest in Koje-Do than at the C. japonica forest in Haenam. These amounts were 5, 282.1 $\pm$ 1, 026.03g/m2 in Koje-Do and 1, 420.7 $\pm$ 384.77g/$m^2$ in haenam. The decomposition rate were rarely differnet at each forest in Haenam, but the rates showed great difference at C. japonica foreests in Koje-Do and Haenam. The rates were 0.093 and 0.313 at C. japonica forests in Koje-Do and in Haenam respectively. The sodium contents were 0.472% and 0.229% on L layer and on Css layer of C. japonica forest in Koje-Do, while they were 0.034% and 0.043% on L layer, and on Css layer of C. jpaonica forest in Haenam. It is sugested that much difference in the salt contents in the forest floor was present from the results of sodium content measured at each site, and that the decomposition rate was affected by the much concentration of salt in Koje-Do.

• Applied Biological Chemistry
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• v.10
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• pp.1-13
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• 1968

Phytin is a salt(mainly calcium and magnesium) of phytic acid and its purity and molecular formula can be determined by assaying the contents of phosporus, calcium and magnesium in phytin. In order to devise a new method for the quantitative analysis of the three elements in phytin, the chelatometric method was developed as follows: 1) As the pretreatment for phytin analysis, it was ashfied st $550{\sim}600^{\circ}C$ in the presence of concentrated nitric acid. This dry process is more accurate than the wet process. 2) Phosphorus, calcium and megnesium were analyzed by the conventional and the new method described here, for the phytin sample decomposed by the dry process. The ashfied phytin solution in hydrochloric acid was partitioned into cation and anion fractions by means of a ration exchange resin. A portion of the ration fraction was adjusted to pH 7.0, followed by readjustment to pH 10 and titrated with standard EDTA solution using the BT [Eriochrome black T] indicator to obtain the combined value of calcium and magnesium. Another portion of the ration fraction was made to pH 7.0, and a small volume of standard EDTA solution was added to it. pH was adjusted to $12{\sim}13$ with 8 N KOH and it was titrate by a standard EDTA solution in the presence of N-N[2-Hydroxy-1-(2-hydroxy-4-sulfo-1-naphytate)-3-naphthoic acid] diluted powder indicator in order to obtain the calcium content. Magnesium content was calculated from the difference between the two values. From the anion fraction the magnesium ammonium phosphate precipitate was obtained. The precipitate was dissolved in hydrochloric acid, and a standard EDTA solution was added to it. The solution was adjusted to pH 7.0 and then readjusted to pH 10.0 by a buffer solution and titrated with a standard magnesium sulfate solution in the presence of BT indicator to obtain the phosphorus content. The analytical data for phosphorus, calcium and magnesium were 98.9%, 97.1% and 99.1% respectively, in reference to the theoretical values for the formula $C_6H_6O_{24}P_6Mg_4CaNa_2{\cdot}5H_2O$. Statical analysis indicated a good coincidence of the theoretical and experimental values. On the other hand, the observed values for the three elements by the conventional method were 92.4%, 86.8% and 93.8%, respectively, revealing a remarkable difference from the theoretical. 3) When sodium phytate was admixed with starch and subjected to the analysis of phosphorus, calcium and magnesium by the chelatometric method, their recovery was almost 100% 4) In order to confirm the accuracy of this method, phytic acid was reacted with calcium chloride and magnesium chloride in the molar ratio of phytic: calcium chloride: magnesium chloride=1 : 5 : 20 to obtain sodium phytate containing one calcium atom and four magnesium atoms per molecule of sodium phytate. The analytical data for phosporus, calcium and magnesium were coincident with those as determine d by the aforementioned method. The new method employing the dry process, ion exchange resin and chelatometric assay of phosphorus, calcium and magnesium is considered accurate and rapid for the determination of phytin.

• The Korean Journal of Community Living Science
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• v.25 no.2
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• pp.261-269
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• 2014

This study evaluates the nutritional retention factors influencing beef based on different cuts and boiling. Two cuts (brisket and shin foreshank) were prepared from beef and used in this experiment. Boiling methods were applied to each cut. The fat content of the boiled shin foreshank cut (236.43%) exceeded that of the brisket cut (142.38%). The moisture content of the boiled brisket cut (47.68%) was lower than that of the shin foreshank cut (49.54%). The sodium content of the boiled shin foreshank cut (47.89%) exceeded that of the brisket cut (37.30%). The potassium content of the boiled brisket cut (41.90%) exceeded that of the shin foreshank cut (39.63%). The calcium content of the boiled brisket cut (48.43%) was lower than that off the shin foreshank cut (71.34%). The phosphorus content of the boiled brisket cut (58.09%) exceeded that of the shin foreshank cut (57.24%). The iron content of the boiled brisket cut (72.72%) was lower than that of the shin foreshank cut (87.29%). Nutritional retention factors represent output data on cooking methods with a yield (%) for each item.

• Clean Technology
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• v.29 no.2
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• pp.95-101
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• 2023

An experiment was conducted to produce vaterite-type precipitated calcium carbonate from waste oyster shells in order to use them as recyclable resources. Calcined oyster shells containing calcium oxide as their main component were prepared at a temperature of 800℃ for 24 h. The oyster shells were dissolved in nitric acid or hydrochloric acid solution to make 0.1 M calcium nitrate or calcium chloride aqueous solution, and a carbonation reaction was performed using a 0.1 M sodium carbonate aqueous solution under various experimental conditions, which included varying the amount of aspatic acid additive, the amount of NH₄OH added, the reaction time, the reaction temperature, the stirring speed, and the type of dissolved acid. The XRD, SEM, and size distributions were analyzed and the vaterite content was calculated. Spherical precipitated calcium carbonate with a vaterite content of 95.9% was synthesized by adding 0.1 mol aspatic acid/1 mol CaO and 2 cm³ of NH₄OH, and reacting for 1 h at 25℃ while stirring at 600 rpm. The average particle diameter was found to be 12.11 ㎛. Calcium carbonate contatining high vaterite is used as high value added calcium carbonate for medical, food, inke additiver, etc.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.263-274
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• 1989

The present study was conducted ill. order to get the normal blood chemical values of Korean Jindo dogs. Blood samples were taken from 160(♂34, ♀126) healthy Jindo dogs in Jindo area. The results obtained in this study were summarized as follows: 1. The mean values of serum total protein(TP), albumin(Alb) and globulin(Glb) content, cholesterol(Chole), magnesium(Mg), calcium(Ca), inorganic phosphate(P), potassium(K), sodium(Na) and chloride(Cl) concentration in the group of less than one year old were 6.64(♂6.62, ♀6.64), 3.63(♂3.57, ♀3.65) and 3.00(♂3.05, ♀2.99)g/100ml, 170.97(♂166.46, ♀172.68)mg/100ml, 1.45(♂1.43, ♀1.46), 5.76(♂5.62, ♀5.81), 4.80(♂4.95, ♀4.75), 4.84(♂4.72, ♀4.89), 148.93(♂148.79, ♀148.98) and 110.22(♂110.42, ♀110.14)mEq/L, respectively, whereas the TP, Alb and Glb content, Chole Mg, Ca, P, K, Na and Cl concentration in the group of one year old and more were 6.88(♂6.84, ♀6.89), 3.65(♂3.63, ♀3.66) and 3.23(♂3.21, ♀3.23)g/100ml, 167.48(♂173.80, ♀166.48)mg/100ml, 1.40(♂1.36, ♀1.40), 5.69(♂5.53, ♀5.71), 4.62(♂4.73, ♀4.60), 4.88(♂4.90, ♀4.87), 149.86(♂149.60, ♀149.90) and 110.03(♂110.70, ♀109.92)mEq/L, respectively. The ratios of mean serum albumin to globulin(A/G), calcium to inorganic phosphate(Ca/P) and sodium to potassium(Na/K) in the group of less than one year old were 1.21(♂1.17, ♀1.22), 1.20(♂1.14, ♀1.22) and 30.77(♂31.52, ♀30.47), respectively, whereas the A/G, Ca/P and Na/K in the group of one year old and more were 1.13(♂1.13, ♀1.13), 1.23(♂1.17, ♀1.24) and 30.71(♂30.53, ♀30.78), respectively. 2. The mean values of Alb content, Mg, Ca and K concentration, A/G and Ca/P ratio appeared to be higher in the female than in the male, whereas the reverse was the case with P concentration. No differences were found between male and female in the TP and Glb content, Chole, Na and Cl concentration and Na/K ratio. 3. The mean values of Glb content appeared to be higher in the group less than one year old than in the group of one year old and more, whereas the reverse was the case with A/G ratio. The mean values of TP and Alb content and Ca/P ratio in the age groups less than one year tended to increase with aging, whereas the reverse was the case with Ca and P concentration. No differences were found between age groups in the Mg, K, Na and Cl concentration and Na/K ratio.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.11.1-11.10
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• 2018

Objectives: This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. Materials and Methods: Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. Results: In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001). Conclusions: Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.

• The Korean Journal of Food & Health Convergence
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• v.9 no.2
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• pp.19-24
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• 2023

In this study, we tried to compare and analyze the taste components of Korean Ganjang made by a conventional method on a small scale and aged for 3 years and brewed Ganjang produced by a large company. As a result of the study, a total of 22 types of free amino acids in liver were detected. The main amino acids of Korean Ganjang were glutamic acid, lysine, serine, citrulline, alanine, and leucine, then, the main amino acids of brewed Ganjang were leucine, glutamic acid, aspartic acid, valine, serine, alanine. The content of glutamic acid in the composition of free amino acid was 12133.69 mg/mL, more than twice as much as that of Korean Ganjang. The content of leucine (bitter taste) was 5933.37 mg/mL of brewed Ganjang, which was 2.9 to 7 times higher than that of Korean Ganjang. Overall, the content of glass amino acids with savory, sweet, and bitter flavors was found to be very high in brewed Ganjang (BGS) than in Korean Ganjang (KAS, KBS, and KCS). On the other hand, GABA was 456.43 mg/mL for Korean Ganjang KBS, 3.3 times higher than brewed Ganjang. Brewed Ganjang had higher glucose content, inorganic content, iron (Fe), organic acid lactic acid and acetic acid content than Korean Ganjang. Korean Ganjang was found to contain high saturated fatty acids, calcium (Ca), and sodium (Na).

• Clean Technology
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• v.24 no.4
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• pp.315-322
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• 2018

Industrial use of waste oyster shells is limited because of requiring excessive energy for converting natural oyster shells in the form of calcium carbonate ($CaCO_3$) into calcium oxide (CaO) for this purpose. This study aimed to develop energy-saving process for producing solidifying agent using waste oyster shells for backfill materials. It was suggested that oyster shells were converted to calcium sulfates which were mixed with sodium hydroxide solution and red clay, forming solid specimen. The optimal concentrations of sulfuric acid for sulfation of oyster shell and sodium hydroxide to generate calcium hydroxide ($Ca(OH)_2$), were determined. Unconfined compressive strength of solid specimen increased with increasing the content of solidifying agent while it increased also with increasing ratio of natural oyster shells to coal ash. The result clearly demonstrates that solidifying agent consisting of sulfuric acid-treated oyster shell, coal ash, and sodium hydroxide solution, can be effectively utilized for preparing backfill materials using natural oyster shell and coal ash. Sulfuric acid-treated oyster shell-based solidifying agent has not been previously developed and will contribute to broaden industrial application of waste oyster shells.