• Title/Summary/Keyword: Minimum Resistance

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A New White Wheat Variety, "Jeokjoong" with High Yield, Good Noodle Quality and Moderate to Scab (백립계 다수성 붉은곰팡이병 중도저항성 제면용 밀 신품종 "적중밀")

  • Park, Chlul Soo;Heo, Hwa-Young;Kang, Moon-Suk;Lee, Chun-Kee;Park, Kwang-Geun;Park, Jong-Chul;Kim, Hong-Sik;Kim, Hag-Sin;Hwang, Jong-Jin;Cheong, Young-Keun;Kim, Jung-Gon
    • Korean Journal of Breeding Science
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    • v.40 no.3
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    • pp.308-313
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    • 2008
  • "Jeokjoong", a white winter wheat (Triticum aestivum L.) variety was developed from the cross "Keumkang"/"Tapdong". "Jeokjoong" is an awned, semi-dwarf and soft white winter wheat, similar to "Keumkang" (check variety). The heading and maturing date of "Jeokjoong" were similar to "Keumkang". Culm and spike length of "Jeokjoong" were 78 cm and 7.5 cm, similar to "Keumkang". "Jeokjoong" had lower test weight (800 g) and lower 1,000-grain weight (40.1 g) than "Keumkang" (811 g and 44.0 g, respectively). It had resistance to winter hardiness, wet-soil tolerance and lodging tolerance. "Jeokjoong" showed moderate to scab in test of specific character although "Keumkang" is susceptible to scab. "Jeokjoong" had lower flour yield (69.2%) and ash content (0.36%) than "Keumkang" (72.0% and 0.41%, respectively) and similar flour color to "Keumkang". It showed lower protein content (8.9%) and SDS-sedimentation volume (36.8 ml) and shorter mixograph mixing time (3.5 min) than "Keumkang" (11.0%, 59.7 ml and 4.5 min, respectively). Amylose content and pasting properties of "Jeokjoong" were similar to "Keumkang". "Jeokjoong" had softer and more elastic texture of cooked noodles than "Keumkang". Average yield of "Jeokjoong" in the regional adaptation yield trial was 6.19 MT ha-1 in upland and 5.33 MT/ha in paddy field, which was 19% and 16% higher than those of "Keumkang" (5.21 MT/ha and 4.58 MT/ha, respectively). "Jeokjoong" would be suitable for the area above the daily minimum temperature of $-10^{\circ}C$ in January in Korean peninsula.

A New Six-rowed and Covered Barley Cultivar, "Hyedang" with Lodging Tolerance and High-Yield (내도복 다수성 겉보리 신품종 "혜당")

  • Kim, Yang-Kil;Baek, Seong-Bum;Kim, Jung-Gon;Lee, Mi-Ja;Kim, Mi-Jung;Kim, Hong-Sik;Park, Jong-Chul;Hyun, Jong-Nae;Suh, Sae-Jung;Kim, Si-Ju;Kim, Jae-Chul;Jeung, Jai-Hyun;Choi, Jae-Seong
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.630-634
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    • 2009
  • "Hyedang", a new covered cultivar derived from the crosses between "Suwon300" and "Haganemugi//CI08397/Haganemugi" developed at the Honam Agricultural Research Institute (HARI), NICS, RDA in 2007. The origin of "Hyedang" is "Iksan 407" (SB951033-B-B-B-72). The initial cross was made in 1995 and the selected line showed a high yield and good quality characteristics under yield trial test in 2004. "Iksan407" consistently performed well for three years (2005-2007) from the four locations of regional yield trial (RYT) in Korea and released as "Hyedang". The characteristics of "Hyedang" were the following: rate III growth habit, green leaf and stem, compact spike and with long rough awns. The heading date was April 25 in upland and April 17 in paddy field, which was 2 and 3 days earlier than that of check cultivar, "Olbori". The culm length was 80 cm which was 8 cm shorter than those of check cultivar. It showed spike length of 4.3 cm and 696 spikes per $m^2$, 51 grains per spike, 35.0 g of 1,000 grain weight and 704 g of test weight. It showed stronger winter hardiness and higher resistance to barley yellow mosaic virus (BaYMV) than those with check cultivar. It showed similar protein content and higher whiteness than those of the check cultivar and diastatic power was higher than that of Olbori. The average yield of the pearled grain in the RYT was $4.17ton\;ha^{-1}$ in upland and $4.27ton\;ha^{-1}$ in paddy field, which was 23% and 9% higher than that of the check cultivar, respectively. This cultivar would be suitable for the area above the daily minimum mean temperature of $-8^{\circ}C$ in January in Korean peninsula.

A New Wheat Variety, "Sukang" with Good Noodle Quality, Resistant to Winter Hardiness and Pre-harvest Sprouting (내한 내수발아성 제면용 밀 신품종 "수강밀")

  • Park, Chlul Soo;Heo, Hwa-Young;Kang, Moon-Suk;Kim, Hong-Sik;Park, Hyung-Ho;Park, Jong-Chul;Kang, Chon-Sik;Kim, Hag-Sin;Cheong, Young-Keun;Park, Ki-Hun
    • Korean Journal of Breeding Science
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    • v.41 no.1
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    • pp.44-50
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    • 2009
  • "Sukang", a winter wheat (Triticum aestivum L.) cultivar was developed by the National Institute of Crop Science, RDA. It was derived from the cross "Suwon266" / "Asakaze" during 1994. "Sukang" was evaluated as "Iksan312" in Advanced Yield Trial Test in 2005. It was tested in the regional yield trial test between 2006 and 2008. "Sukang" is an awned, semi-dwarf and hard winter wheat, similar to "Keumkang" (check cultivar). The heading and maturing date of "Sukang" were similar to "Keumkang". Culm and spike length of "Sukang" were 90 cm and 8.1 cm, longer culm length and similar spike length compared to "Keumkang" (80 cm and 7.9 cm, respectively). "Sukang" had similar test weight (819 g/L) and lower 1,000-grain weight (40.2 g) than "Keumkang" (813 g/L and 44.9 g, respectively). "Sukang" showed resistance to winter hardiness and pre-harvest sprouting, which lower withering rate on the high ridge (4.5%) and rate of pre-harvest sprouting (0.2%) than "Keumkang" (21.9% and 30.4%, respectively). "Sukang" had lower flour yield (71.1%) and higher ash content (0.45%) than "Keumkang" (74.1% and 0.42%, respectively). "Sukang" showed lower lightness (89.13) and higher yellowness (10.93) in flour color than "Keumkang" (90.02 and 9.28, respectively). It showed higher protein content (12.8%) and gluten content (11.1%) and lower SDS-sedimentation volume (56.8 ml) and mixing time of mixograph (2.6 min) than "Keumkang" (11.9%, 10.2%, 62.3 ml and 4.7 min, respectively). Fermentation properties, amylose content and pasting properties of "Sukang" were similar to "Keumkang". "Sukang" showed different compositions in high molecular weight glutenin subunits (HMW-GS, $2^{\ast}$, 13+16, 2+12) and puroindolines (pina-1b/pinb-1a) compared to "Keumkang" ($2^{\ast}$, 7+8, 5+10 in HMW-GS and Pina-1a/Pinb-1b in puroindolines, respectively). "Sukang" showed lower hardness (4.53 N) and similar springiness and cohesiveness of cooked noodles (0.94 and 0.63) compared to "Keumkang" (4.65 N, 0.93 and 0.64, respectively). Average yield of "Sukang" in the regional adaptation yield trial was 5.34 MT/ha in upland and 4.72 MT/ha in paddy field, which was 4% and 1% lower than those of "Keumkang" (5.55 MT/ha and 4.77 MT/ha, respectively). "Sukang" would be suitable for the area above $-10^{\circ}C$ of daily minimum temperature in January in Korean peninsula.

Naked Waxy Barley Cultivar "Jinjuchal" with High Whiteness after Cooking and High β-glucan Content (취반 후 백도가 좋고 베타글루칸 함량이 높은 찰성 쌀보리 "진주찰")

  • Lee, Mi-Ja;Seo, Jae-Hwan;Kim, Yang-Kil;Park, Jong-Chul;Choi, Jae-Seong;Park, Tae-Il;Hyun, Jong-Nae;Kim, Jung-Gon
    • Korean Journal of Breeding Science
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    • v.41 no.3
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    • pp.299-305
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    • 2009
  • A new six-rowed naked barley cultivar "Jinjuchal" with high whiteness after cooking and high $\beta$-glucan content was developed from the cross between 'Jinmichapssalbori' with high winter hardiness, lodging tolerance, grain whiteness and pearling yield, and 'Suwon 333' with waxy endosperm by the Honam Agricultural Research Institute (HARI), NICS, RDA in 2007. An elite line, SB962002G-B-B-B-84-4 was selected in 2002 and designated as 'Iksan 79' It showed good agronomic performance in the regional yield trials (RYT) from 2005 to 2007 and was released with the name of "Jinjuchal" possessing high whiteness and low proanthocyanidin waxy endosperm. The average heading and maturing dates of "Jinjuchal" were April 27 and June 1 in paddy field, which were same and one day later than those of the check cultivar 'Saechalssalbori' respectively. The new cultivar, "Jinjuchal" had 81 cm of culm length that was 1cm longer than that of 'Saechalssalbori' and 4.9 cm of spike length. It showed 673 spikes per $m^2$, 56 grains per spike, 27.0 g of 1,000-grain weight, and 752 g of test weight. "Jinjuchal" showed stronger hardiness and better resistance to powdery mildew and BaYMV (Barley yellow mosaic virus) than those of the check cultivar, 'Saechalssalbori' It showed higher $\beta$-glucan content(8.4%) and water absorption rate than those of the check cultivar, 'Saechalssalbori' Its average yield of the pearled grain in the regional yield trial was 3.79 MT/ha in upland, and 3.73 MT/ha in paddy field, which were 1% lower and 3% higher than those of the check cultivar, respectively. Total phenol and proanthocyanidin contents were 4.2 and 0.2 mg/g, respectively. This cultivar is suitable for the area of the daily minimum temperature above $-6^{\circ}C$ in January in Korean peninsula.

"Jungmo2501", A Winter Oat (Avena sativa L.) Cultivar of Lodging Tolerance, Early-Heading and High Forage Yield (조숙 내도복 다수성 추파용 총체귀리 품종 '중모2501')

  • Han, Ouk-Kyu;Park, Tae-Il;Park, Hyung-Ho;Park, Ki-Hun;Oh, Young-Jin;Kim, Kee-Jong;Ju, Jung-Il;Jang, Young-Jik;Park, Nam-Geon;Kim, Dea-Wook;Ku, Ja-Hwan;Kweon, Soon-Jong;Ahn, Jong-Woong
    • Korean Journal of Breeding Science
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    • v.49 no.2
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    • pp.80-86
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    • 2017
  • 'Jungmo2501' (Avena sativa L.), a winter oat for forage use, was developed by the breeding team at the National Institute of Crop Science, RDA in 2010. The following is the characteristics of 'Jungmo2501' that is characterized as light green leaf, yellow brown culm and whitish yellow grain. The heading date of 'Jungmo2501' was about 3 days earlier than that of check cultivar 'Samhan'(May 7 and May 10, respectively). Its plant height was 11 cm longer than 103 cm of the check, and the leaf blade ratio of aerial parts was 26 % higher than the check (11.8% and 9.4%, respectively). The cold tolerance, resistance to lodging and wet injury of 'Jungmo2501' were similar to those of the check. The average forage dry matter yield of 'Jungmo2501' harvested at milk-ripe stage was 5% higher than the check ($15.5ton\;ha^{-1}$ and $14.7ton\;ha^{-1}$, respectively). 'Jungmo2501' was higher than the check in terms of protein content (6.6% and 5.9%, respectively), neutral detergent fiber (58.5% and 57.6%, respectively), and acid detergent fiber (34.5% and 32.1%, respectively), while total digestible nutrients was lower than the check (61.6% and 63.6%, respectively), and TDN yield was $0.37ton\;ha^{-1}$ more than that of the check ($9.71ton\;ha^{-1}$ and $9.34ton\;ha^{-1}$, respectively). The silage grade of 'Jungmo2501' estimated by Flig score showed level II, meaning good quality. Fall sowing cropping of 'Jungmo2501' is recommended only for areas where average daily minimum mean temperatures in January are higher than $-6^{\circ}C$.

A New White Wheat Variety, "Hanbaek" with Good Noodle Quality, High Yield and Resistant to Winter Hardiness (내한 다수성 백립계 제면용 밀 신품종 "한백밀")

  • Park, Chlul-Soo;Heo, Hwa-Young;Kang, Moon-Suk;Kim, Hong-Sik;Park, Hyung-Ho;Park, Jong-Chul;Kang, Chon-Sik;Kim, Hag-Sin;Cheong, Young-Keun;Park, Ki-Hun
    • Korean Journal of Breeding Science
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    • v.41 no.2
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    • pp.130-136
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    • 2009
  • "Hanbaek", a white winter wheat (Triticum aestivum L.) cultivar was developed by the National Institute of Crop Science, RDA. It was derived from the cross "Shan7859/Keumkang"//"Guamuehill" during 1996. "Hanbaek" was evaluated as "Iksan314" in Advanced Yield Trial Test in 2005. It was tested in the regional yield trial between 2006 and 2008. "Hanbaek" is an awned, semi-dwarf and hard winter wheat, similar to "Keumkang" (check cultivar). The heading and maturing date of "Hanbaek" were similar to that of "Keumkang". Culm and spike length of "Hanbaek" were 89 cm and 9.0 cm, which longer culm length and spike length than "Keumkang" (80 cm and 7.9 cm, respectively). "Hanbaek" had lower test weight (797 g) and higher 1,000-grain weight (47.7 g) than "Keumkang" (813 g and 44.9 g, respectively). "Hanbaek" showed resistance to winter hardiness and susceptible to pre-harvest sprouting, which lower withering rate on the high ridge (4.4%) and higher rate of pre-harvest sprouting (47.9%) than "Keumkang" (21.9% and 30.4%, respectively). "Hanbaek" had similar flour yield (74.4%) to "Keumkang" (74.1%) and higher ash content (0.45%) than "Keumkang" (0.42%). "Hanbaek" showed lower lightness (89.13) and similar redness and yellowness (-0.87 and 10.93) in flour color than "Keumkang" (90.02, -1.23 and 9.28, respectively). It showed similar protein content (12.8%) SDS-sedimentation volume (63.0 ml) and gluten content (10.8%) to those of "Keumkang" (11.9%, 62.3 ml and 10.2%, respectively). It showed lower water absorption (59.6%) and mixing time (3.8 min) in mixograph and higher fermentation volume (1,350 ml) than those of "Keumkang" (60.6%, 4.7 min and 1,290 ml, respectively). Amylose content and pasting properties of "Hanbaek " were similar to those of "Keumkang". "Hanbaek" showed same compositions in high molecular weight glutenin subunits (HMW-GS, 2*, 13+16, 2+12), granule bound starch synthase (Wx-A1a, Wx-B1a, and Wx-D1a) and puroindolines (Pina-D1a/Pinb-D1b) compared to "Keumkang". "Hanbaek" showed lower hardness (4.22N) and similar springiness and cohesiveness of cooked noodles (0.94 and 0.63) to those of "Keumkang" (4.65N, 0.93 and 0.64, respectively). Average yield of "Hanbaek" in the regional adaptation yield trial was 5.98 MT/ha in upland and 5.05 MT/ha in paddy field, which was 8% and 6% higher than those of "Keumkang" (5.55 MT/ha and 4.77 MT/ha, respectively). "Hanbaek" would be suitable for the area above the daily minimum temperature of $-10^{\circ}C$ in January in Korean peninsula.

A New White Wheat Variety, "Baegjoong" with High Yield, Good Noodle Quality and Moderate to Pre-harvest Sprouting (백립계 다수성 수발아 중도저항성 제면용 밀 신품종 "백중밀")

  • Park, Chul Soo;Heo, Hwa-Young;Kang, Moon-Suk;Lee, Chun-Kee;Park, Kwang-Geun;Park, Jong-Chul;Kim, Hong-Sik;Kim, Hag-Sin;Hwang, Jong-Jin;Cheong, Young-Keun;Kim, Jung-Gon
    • Korean Journal of Breeding Science
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    • v.40 no.2
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    • pp.153-158
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    • 2008
  • "Baegjoong", a white winter wheat (Triticum aestivum L.) cultivar was developed by the National Institute of Crop Science, RDA. It was derived from the cross "Keumkang"/"Olgeuru" during 1996. "Baegjoong" was evaluated as "Iksan307" in Advanced Yield Trial Test in 2004. It was tested in the regional yield trial test between 2005 and 2007. "Baegjoong" is an awned, semi-dwarf and soft white winter wheat, similar to "Keumkang" (check cultivar). The heading and maturing date of "Baegjoong" were similar to "Keumkang". Culm and spike length of "Baegjoong" were 77 cm and 7.5 cm, similar to "Keumkang". "Baegjoong" had lower test weight (802 g) and lower 1,000-grain weight (39.8 g) than "Keumkang" (811 g and 44.0 g, respectively). It had resistance to winter hardiness, wet-soil tolerance and lodging tolerance. "Baegjoong" showed moderate to pre-harvest sprouting (23.9%) although "Keumkang" is susceptible to pre-harvest sprouting (38.9%). "Baegjoong" had similar flour yield (72.4%) and ash content (0.41%) to "Keumkang" (72.0% and 0.41%, respectively) and similar flour color to "Keumkang". It showed lower protein content (8.8%) and SDS-sedimentation volume (35.3 ml) and shorter mixograph mixing time (3.8 min) than "Keumkang" (11.0%, 59.7 ml and 4.5 min, respectively). Amylose content and pasting properties of "Baegjoong" were similar to "Keumkang". "Baegjoong" had softer and more elastic texture of cooked noodles than "Keumkang". Average yield of "Baegjoong" in the regional adaptation yield trial was $5.88\;MT\;ha^{-1}$ in upland and 5.35 MT ha-1 in paddy field, which was 13% and 17% higher than those of "Keumkang" ($5.21\;MT\;ha^{-1}$ and $4.58\;MT\;ha^{-1}$, respectively). "Baegjoong" would be suitable for the area above the daily minimum temperature of $-10^{\circ}C$ in January in Korean peninsula.

A New Forage Barley (Hordeum vulgare L.) Cultivar 'Mihan' with Ruminant-Palatable Semi-Smooth Awn (가축 기호성이 좋은 반매끈망을 가진 청보리 신품종 '미한')

  • Park, Jong-Ho;Cheong, Young-Keun;Kim, Kyong-Ho;Park, Tae-Il;Kim, Yang-Kil;Park, Hyoung-Ho;Yoon, Young-Mi;Han, Ouk-Kyu;Yun, Geon-Sig;Hong, Ki-Heung;Bae, Jeong-Suk;Song, Jae-Ki;Oh, Young-Jin
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.38 no.4
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    • pp.253-259
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    • 2018
  • A new barley (Hordeum vulgare L.) cultivar 'Mihan' having ruminant-palatable semi-smooth awn and good silage quality was developed at National Institute of Crop Science(NICS), RDA in 2016. This cultivar was derived from a cross of the 'SB00T2064' and 'Suwon385' in 2001. And its promising line showed high yielding through the preliminary yield trials(PYT) and advanced yield trials (AYT) in Iksan from 2012 to 2013. It was designated as the 'Iksan487'. 'Iksan487' was conducted to regional yield trials (RYT) in one upland field and five paddy fields around Korea for three years from 2014 to 2016. And it was released as the name of 'Mihan'. It has growth habit of IV, erect plant type, green leaf and semi-smooth awn. Its heading date was April 23 in the paddy field and maturing date was May 24. Plant height of 'Mihan' was 96cm. Mihan's spikes per $m^2$ was 665. It has better winter hardiness and resistance to BaYMV (Barley Yellow Mosaic Virus) than that of barley cultivar 'Youngyang'. The average dry matter of 'Mihan' was about $10.9ton\;ha^{-1}$ in paddy field. And average feed quality of 'Mihan' was 10.3% of crude protein content, 26.1% of ADF (Acid Detergent Fiber), 46.9 % of NDF (Neutral Detergent Fiber) and 68.2% of TDN (Total Digestible Nutrients). 'Mihan' had grade I of silage quality. This cultivar would be suitable for the area above the daily minimum average temperature of $-8^{\circ}C$ in January in Korean peninsula.

A Study on Wintering Microclimate Factors of Evergreen Broad-Leaved Trees, in the Coastal Area of Incheon, Korea (인천해안지역의 난온대성 상록활엽수 겨울철 생장에 영향을 미치는 미기후 요인)

  • Kim, Jung-Chul;Kim, Do-Gyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.5
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    • pp.66-77
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    • 2019
  • This study investigated the feasibility of wintering evergreen broad-leaf trees in the Incheon coastal area through a climate analysis. The coldest monthly mean air temperature ranged from $-2.9^{\circ}C{\sim}-1.6^{\circ}C$. The warmth index of the coastal area of Incheon ranged from $98.89^{\circ}C{\cdot}month-109.03^{\circ}C{\cdot}month$, while the minimum air temperature year ranged from $-13.9^{\circ}C{\sim}-3.6^{\circ}C$. This proved that the Incheon coastal area was not suitable for evergreen broad-leaf trees to grow as the warmth index ranges from $101.0^{\circ}C{\cdot}month{\sim}117.0^{\circ}C{\cdot}month$, and the temperature year-round is $-9.2^{\circ}C$ or higher. This suggests the coastal areas of Incheon is not suitable for the growth of evergreen broad-leaf trees, however some evergreen broad-leaf trees lived in some parts of the area. Wind speed reduction and temperature effect simulations were done using Landschaftsanalyse mit GIS program. As a result of the simulations of wind speed reduction and temperature effects affecting the evergreen broad-leaf trees, it was discovered that a coastal wind velocity of 8.6m/sec was alleviated to be 5m/sec~7m/sec when the wind reached the areas where evergreen broad-leaf trees were present. It was also discovered that species that grew in contact with buildings benefited from a temperature increase of $1.1^{\circ}C{\sim}3.4^{\circ}C$ due to the radiant heat released by the building. Simulation results show that the weather factors affecting the winter growth damages of evergreen broad-leaved trees were wind speed reduction and local warming due to buildings. The wind speed reduction by shielding and local warming effects by buildings have enabled the wintering of evergreen broad-leaved trees. Also, evergreen broad-leaved trees growing in the coastal area of Incheon could be judged to be gradually adapting to low temperatures in winter. This study reached the conclusion that the blockage of wind, and the proximity of buildings, are required for successfully wintering evergreen broad-leaf trees in the coastal area of Incheon.

Studies on the Durability of Mortars (모르타르의 내구성에 관한 연구)

  • 고재군
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.11 no.1
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    • pp.1604-1615
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    • 1969
  • This experiment was carried out as one of the basic studies to improve the acid resistance of concrete and it was conducted to investigate some relations among physical properties such as basorption, ratio of water to cement, compressive strength, density and ratio of mix to weight losses of mortar when exposed to 0.1 N solution of hydrochrolic acid. The results obtained from the limited data secured so far in this experiment are summarized as follows: 1. The specimens used in the experiment were made of 5 cubic centimeters of mortar having such various ratios of mix by weight as 1 : 1, 1 : 3, 1 : 5, 1 : 7, 1 : 10. 2. Physical tests included compressive strengths at 7 days, 28 days, 3 months, and 6 month, and 5 hour boiling absorption test. 3. In acid test, every specimen was immersed into 0.1 N solution of hydrochrolic acid. The specimens exposed to the acid solution were weighed to determine the weight losses of the acid-corroded at one week interval for 7 weeks exposure, and the old acid solutions were also changed to fresh one when weighed the weight losses by acid attack at one week interval. 4. The correlative relations were found among physical properties and they are expressed by certain formulas as follows; i) Relation between ratio of mix and absorption Y = 1.036x + 13.53 where Y: absorption(%) X: ratio of mix ii) Relation between ratio of mix and ratio of water-cement Y = 0.204x + 0.214 where Y: ratio of water-cement. X: ratio of mix iii) Relation between ratio of water-cement and absorption Y = 5.01x + 12.53 where Y: absorption(%). X: ratio of water-cement iv) Relation between density and absorption Y = 50.6 - 0.0176X where Y: absorption(%). X: density($kg/m^3$) v) Relation between density and ratio of water cement Y = 7.2183 - 0.0033X where Y: ratio of water-cement . X: density($kg/m^3$) 5. After completing the acid exposure test the specimens were corroded and , the per cent ranges of weight losses varies from a minimum of 20.4 per cent at a 1 : 1 mix to a maximum of 92.0 per cent at a 1:10 mix 6. The correlative relations of physical properties of mortar to weight losses by acid attak were found and they are also expressed by certain formulas as follows: i) Relation between weight losses and ratio of mix Y = 8.59X + 8.63 where Y: weight losses(%), X: ratio of mix ii) Relation between wieght losses and absorption Y = 0.121x + 12.43 where Y: absorption(%). X: weight losses(%) iii) Relation between weight losses and ratio of w/c Y = 0.0226X + 0.07 where Y: ratio of w/c X: weight losses(%) iv) Relation between weight losses and compressive strength LogY = 3.6097 - 0.05058X + 0.00022$X^2$ where Y: compressive strength ($kg/cm^3$) X: weight losses(%) v) Relation between weight losses and density Y = 2153.1 - 6.62X where Y: density($kg/m^3$) X: weigh losses(%) 7. In order to make better acid resistant mortar, it could be concluded that a 1 : 3 mix or richer mixes, adequate mixing water to minnimize the ratio of water-cement considering the workability, 16 per cent or less absorption by 5 hour boiling water, 1,800 kilogram per cubic meter or denser density by absolute weight base and 200 kilogram per square meter or compressive strength at 20 day, etc are required so as to obtain acid-resistant mortar. In addition to the above, it might be recommonded to select the fine aggregate and to use better equipments such as a mechanical vibrator, a mechanical mixer etc. in concrete manufacturing works.

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