• Korean Journal of Mineralogy and Petrology
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• v.37 no.1
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• pp.1-11
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• 2024

World stone production in 2021 stood at 162.5 million tons, up by 7.5 million tons, or 4.8 percent, compared to the previous year when the production came in at 155 million tons. Six top countries with the most of stone production were China, India, Turkey, Brazil, Iran and Italy and these six countries accounted for 72.8 percent of total production in the world. Stone exports stood at $21.68 billion in 2021, up by $2.3 billion from the previous year. Exports of raw materials and processed stones stood at 54.4 million tons, up by 2.98 million tons from the previous year. In terms of aggregate exports, exports of natural stones increased by $2.3 billion to $21.7 billion while exports of artificial stones rose $2.6 billion to $13.6 billion in 2021 compared to the previous year. The average price of stone (Code: 68.02) was up by $65.2 per ton to $794.82. The price of board, processed stone, an ingredient for building materials, increased by $3.52 per square meter to $42.96 per square meter. Recycling was always the problem as the volume of the total quarry was 333.5 million tons, of which only 28.8 percent were finished products and the remaining 71.2 percent were waste generated from stone extraction and processing. Korea's stone exports stood at $1.97 million in 2021, down 38.3 percent on year, while imports were up 8.6 percent to $758.9 million. Stone exports are expected to grow to 66.1 million tons in 2025, while usage is expected to reach 108.92 million tons, or 2 billion square meters.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.367-375
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• 2011

For this study, Korean-type Koumiss was made by the fermentation of mixed cultures, in which yeast, Kuyveromyces, and microflora, Streptococcus thermophiles and Lactobacillus bulgaricus, were inoculated into 10% skimmed milk with added whey powder(control: A, 2%: B, 4%: C, 6%: D, and 8%: E). Fat, protein, lactose, titratable acidity, pH, the number of lactic acid bacteria, the number of yeast, alcohol content, volatile fatty acids, volatile free amino acids and minerals were measured in the products. The results were as follows: As the dosage of whey powder increased, fat increased from 0.74% in the control to 2.30% in sample E, protein increased from 2.95% in the control to 4.39% in sample E and lactose increased from 3.10% in the control to 7.43% in sample E. Titratable acidity and pH increased gradually. The number of lactic acid bacteria increased from $10^9\;cfu/m{\ell}$ in the control to $3.8{\times}10^9\;cfu/m{\ell}$ in sample E, and the number of yeast increased from $6.1{\times}10^7\;cfu/m{\ell}$ in the control to $1.65{\times}10^8\;cfu/m{\ell}$ in sample E, according to the increase of whey powder content. For alcohol content, the average values were 0.863%, 0.967%, 0.890%, 1.290%, and 1.313% for the control and samples B, C, D, and E, respectively. As the dosage of whey powder increased, alcohol content showed a tendency to gradually increase. The average alcohol content of E was 1.313 and this was higher than the alcohol content of Kazahstana-type Koumiss with 1.08%. Sixteen types of free amino acids were detected. Glycine was the lowest in the control at $0.38mg/m{\ell}$ and sample E contained $0.64mg/m{\ell}$. Histidine was also low in the control at $0.42mg/m{\ell}$ and sample E contained $0.65mg/m{\ell}$. On the other hand, glutamic acid was highest at $4.13mg/m{\ell}$ in the control whereas sample E had $6.96mg/m{\ell}$. Proline was also high in the control at $1.71mg/m{\ell}$ in control, but E contained $2.80mg/m{\ell}$. Aspartic acid and leucine were greater in sample E than in the control. For volatile free fatty acids, content generally had a tendency to increase in the control, and samples B, C, D, and E. Content of acetic acid gradually increased from $12,661{\mu}g/100m{\ell}$ in the control to $37,140{\mu}g/m{\ell}$ in sample E. Butyric acid was not detected in the control and was measured as $1,950{\mu}g/100m{\ell}$ in sample E. Caproic acid content was $177{\mu}g/100m{\ell}$ in the control and $812{\mu}g/100m{\ell}$ in sample E, and it increased according to the increase of whey powder content. Valeric acid was measured in a small amount in the control as $22{\mu}g/100m{\ell}$, but it was not detected in any other case. Mineral contents of Ca, P, and Mg increased from 1,042.38 ppm, 863.61 ppm, and 101.28 ppm in the control to 1,535.12 ppm, 1,336.71 ppm, and 162.44 ppm in sample E, respectively. Na content was increased from 447.19 ppm in the control to 1,001.57 ppm in sample E. The content of K was increased from 1,266.39 ppm in the control to 2,613.93 ppm in E. Mineral content also increased with whey powder content. In sensory evaluations, the scores increased as whey powder content increased. Flavor was lowest in the control with 6.3 points and highest in E with 8.2 points. Body and texture were highest at 4.2 points in the control, which did not have added whey powder. In the case of appearance, there were no great differences among the samples.

• Proceedings of the KSEEG Conference
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• 2001.05b
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• pp.42-63
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• 2001

The detail survey on the Songsanri tomb site including the Muryong royal tomb was carried out during the period from May 1 , 1996 to April 30, 1997. A quantitative analysis was tried to find changes of tomb itself since the excavation. Main subjects of the survey are to find out the cause of infiltration of rain water and groundwater into the tomb and the tomb site, monitoring of the movement of tomb structure and safety, removal method of the algae inside the tomb, and air controlling system to solve high humidity condition and dew inside the tomb. For these purposes, detail survery inside and outside the tombs using a electronic distance meter and small airplane, monitoring of temperature and humidity, geophysical exploration including electrical resistivity, geomagnetic, gravity and georadar methods, drilling, measurement of physical and chemical properties of drill core and measurement of groundwater permeability were conducted. We found that the center of the subsurface tomb and the center of soil mound on ground are different 4.5 meter and 5 meter for the 5th tomb and 7th tomb, respectively. The fact has caused unequal stress on the tomb structure. In the 7th tomb (the Muryong royal tomb), 435 bricks were broken out of 6025 bricks in 1972, but 1072 bricks are broken in 1996. The break rate has been increased about 250% for just 24 years. The break rate increased about 290% in the 6th tomb. The situation in 1996 is the result for just 24 years while the situation in 1972 was the result for about 1450 years. Status of breaking of bircks represents that a severe problem is undergoing. The eastern wall of the Muryong royal tomb is moving toward inside the tomb with the rate of 2.95 mm/myr in rainy season and 1.52 mm/myr in dry season. The frontal wall shows biggest movement in the 7th tomb having a rate of 2.05 mm/myr toward the passage way. The 6th tomb shows biggest movement among the three tombs having the rate of 7.44mm/myr and 3.61mm/myr toward east for the high break rate of bricks in the 6th tomb. Georadar section of the shallow soil layer represents several faults in the top soil layer of the 5th tomb and 7th tomb. Raninwater flew through faults tnto the tomb and nearby ground and high water content in nearby ground resulted in low resistance and high humidity inside tombs. High humidity inside tomb made a good condition for algae living with high temperature and moderate light source. The 6th tomb is most severe situation and the 7th tomb is the second in terms of algae living. Artificial change of the tomb environment since the excavation, infiltration of rain water and groundwater into the tombsite and bad drainage system had resulted in dangerous status for the tomb structure. Main cause for many problems including breaking of bricks, movement of tomb walls and algae living is infiltration of rainwater and groundwater into the tomb site. Therefore, protection of the tomb site from high water content should be carried out at first. Waterproofing method includes a cover system over the tomvsith using geotextile, clay layer and geomembrane and a deep trench which is 2 meter down to the base of the 5th tomb at the north of the tomv site. Decrease and balancing of soil weight above the tomb are also needed for the sfety of tomb structures. For the algae living inside tombs, we recommend to spray K101 which developed in this study on the surface of wall and then, exposure to ultraviolet light sources for 24 hours. Air controlling system should be changed to a constant temperature and humidity system for the 6th tomb and the 7th tomb. It seems to much better to place the system at frontal room and to ciculate cold air inside tombs to solve dew problem. Above mentioned preservation methods are suggested to give least changes to tomb site and to solve the most fundmental problems. Repairing should be planned in order and some special cares are needed for the safety of tombs in reparing work. Finally, a monitoring system measuring tilting of tomb walls, water content, groundwater level, temperature and humidity is required to monitor and to evaluate the repairing work.