• Plant Resources
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• v.4 no.1
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• pp.6-12
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• 2001

Growth and yield of licorice were investigated under the different conditions of ridge height, planting density, and irrigation in order to establish its cultural practices for the domestic production with the aim to substitute the import. Seedlings were grown under low ridge(20cm) and high ridge(40cm) in low density plot(60$\times$30cm) and high density plot(40$\times$30cm), respectively. The low ridge cultivation of large seedlings increased plant height and root length under low density, and stem and root diameter under high density compared to the high ridge cultivation. In the high ridge cultivation, high density plot was 1.1 to 1.3 times in plant height, root length, stem and root diameter as high as low density one. Fresh and dry weight of plant and root in high ridge were 1.3 to 1.5 times as high as those in low one. The growth of small seedlings(4~10g) were generally poor compared to that of large seedlings. High density plot in low ridge showed the good growth characteristics including plant height, root length, stem and root diameter, and number of branch. High density plot was 1.4 to 1.6 times in fresh and dry weight of plant and root as high as low density plot. In the seasonal changes of growth under various irrigation regimes, the twice irrigation a day produced the more number of leaf than the other regimes since around 46 days after transplanting. The former irrigation resulted in 1.2 to 1.4 times in plant height as long as the other irrigations around 26 days after transplanting and then the difference was increased to 1.6 to 2.0 times around 64 days after transplanting. Under the twice irrigation a day, plant height, root length, stem diameter, root diameter, number of leaf, fresh plant weight, dry plant weight, fresh root weight, dry root weight were 1.6 to 2.0, 1.1, 1.2 to 1.6, 1.3 to 1.8, 1.9 to 2.7, 1.7 to 8.0, 1.6 to 2.8,2.0 to 3.0, 1.6 to 2.7 times as high as those under the other irrigation regimes, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.205-209
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• 2021

Barnyard millet (Echinochloa esculenta) can be processed through soiling, hay, and silage, depending on the weather conditions during harvesting. However, research on barnyard millet is insufficient, and standards for cultivar, seeding density, and fertilizers have not been established. This study was conducted to examine the effects of seeding density and seeding methods on dry matter yields. For this, we used the early-maturing (Shirohie millet) variety of the barnyard millet. The experimental design included different seeding density (10 kg/ha, 15 kg/ha, 20 kg/ha (standard seeding density), 25 kg/ha and 30 kg/ha), and different methods of seeding (drill seeding and broadcast seeding). The seeding date was May 13, 2021, and the harvest date was July 13, 2021. Harvesting was carried out when the heading reached 40 %. Lodging occurred at 5, 9 and 7 at 20, 25 and 30 kg/ha densities in the broadcast seeding, but not in the drill seeding. With decreasing density of seeding, tillage number showed an increasing trend in both drill seeding and broadcast seeding (p>0.05). The plant heights were comparable in both drill seeding and broadcast seeding (p>0.05). The heading stage of barnyard millet was checked July 7 for drill seeding, and, on July 8 for broadcast seeding. It took 62 days, i.e., till July 13 for the heading to reach 40 % of the output. The dry matter yield of barnyard millet was significantly higher at the seeding density of 30 kg/ha, for both the methods of seeding (p<0.05). There was no difference in the chemical composition of grain, based on the seeding method and seeding density. However, as the seeding density increased, the CP, NDF, ADF, and TDN contents increased in both drill seeding and broadcast seeding. We found that, the dry matter content was the highest at the seeding density of 30 kg/ha for both the methods of seeding, but this was only 1.3 times higher than that of 10 kg/ha. Considering the seed price and labor force involved in seeding, it is advisable to have a seeding density of 15-20 kg/ha.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.207-213
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• 1976

In order to obtain the prediction of the maximum dry density and the optimum moisture content of soil without soil moisture test, compaction test results from 157 different places either under construction or already completed were analyzed. The analyzed results were as follow The relationship between the maximum dry density and the optimum moisture content of the soil showing a correlation coefficient of 0.96 indicated that there was a high correlation between them. From the above relationship we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.4193+0.00937W_{opt.}}$ Equation between the optimum moisture content and the maximum wet density of the soil was $W_{opt.}={\frac{0.4193{\gamma}_{tmax.}}{0.937_{\gamma}_{tmax.}-0.01}$, and the values of the optimum moisture content being predicted with the maximum wet density of the soil showed a little difference between those and tested values. The values of the maximum dry density being predicted with the moisture content estimated by the maximum wet density of the soil were within the range of ${\pm}5%$ of its tested values. The relationship between the dry density and the void ratio showed a high correlation between them (${\gamma}=0.9706$). From the above relationship, we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.3938+0.3426e}}$.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.428-432
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• 2003

In this study, we demonstrated that high cell density for Thiobacillus ferrooxidans could be obtained when optimal conditions for cell growth were maintained using electrochemical cultivation with sufficient aeration. The optimal pH for cultivation were determined to be $2.0{\pm}0.05$. When the current and potential were set to 0.15A, 4V, the Pt electrode reduced $Fe^{3+}$ to $Fe^{2+}$ with efficiency of 85%. Under these condition, cells at an initial density of 0.0025 g-dry cell/L grew for 8days until the cell density was 0.0576 g-dry cell/L. this was a 7-fold increase over conventional batch culture.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.922-925
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• 2007

In the usual dry etching process for the TFT-LCD fabrication, it is hard to monitor the basic plasma parameters such as density and temperature. However, the basic parameters are easily monitored during the dry etching process. We have simultaneously measured the electric characteristics and basic plasma parameters of the dry etching chamber during the process, analyzed them to interpret plasma parameters. For the Ar plasma discharge case, we could obtain the density and temperature from the electric characteristics using a simple simple sheath model.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.34-42
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• 1994

Experiments on the variability of plant type and factors representing the productivity and quality of the cultivars were subsequently carried out in relation to different plant density. Results are summarized as below. The higher was the plant density, the greater was the plant height and mean leaf inclination(MLI). As the plant density increased, the horizontal leaf area distribution became greater in proximal to the stem in NTN 77 and Br.49 but evenly in distal part in Br.21. Meanwhile, in terms of vertical leaf area distribution, it was decreased much more in middle and lower leaves than in upper in NTN 77 and Br.49 although it steadily decreased in any part of the plant in Br.21. Br.49 was the largest but Br.21 and NTN 77 were similar with respect to both CGR and NAR. The yield was greater in larger MLI cultivars(NTN 77>Br.49>Br.21). These three characteristics became greater when the tobacco were planted more densely in the field. Dry leaf weight and dry matter weight per plant were heavier in the larger MLI and increased with lower plant density. Total nitrogen content was greater in lower plant density and larger MLI cultivar. The plant density increases filling power seems to be enhanced regardless to the plant type. There was no discernible tendency on combustibility according to the plant density or plant type.

• Journal of the Korean Geotechnical Society
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• v.38 no.10
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• pp.41-48
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• 2022

The mass density of the medium (ρ) used to calculate the maximum shear modulus (G_max) of the saturated ground based on the shear wave velocity is unclear. Therefore, to determine the mass density, a verification formula and five scenarios were established. Laboratory tests were conducted, and the obtained results were compared. The mass density of the medium was assumed to be saturated (ρ_sat), wet (ρ_t), dry (ρ_dry), and submerged conditions (ρ_sub), and the V_s ratios of saturated to dry condition were obtained from each case. Assuming the saturated density (ρ_sat), the V_s ratio was consistent with the value from the resonant column test (RCT) results, and the value from the bender element test results was consistent with the wet density assumption (ρ_t). Considering the frequency range of earthquakes, it is concluded that applying the saturated density (ρ_sat) is reasonable as in the RCT results.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.3
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• pp.65-77
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• 1981

The Compaction of fill dam is very important for increasing of the safty of dam. Vibration roller is used for the compaction of pervious materials such as sand and gravel. The principal objects of this study are to give a comstruction criteria of vibration roller and to find out the relationship between dry density and permeabity of pervious soil after compaction. The results in this study are summerized as follows. 1.The relationship between maximum dry density (Υdmax) and optimum moisture content(Wo) of modified compaction test is Υdmax=2. 74-0. 064w0 2.The maximum dry density decrease with increasing fine particle(n) and the relative formular is n==ae-brdmax 3.The maximum dry density is influenced more by passing rate of number 200 sieve than 4 sieve. 4.The coefficient of permeability are similar when the degrees of compaction are equal even though the spreading thickness of soil are different. 5.The coefficient of permeability(K)is greatly influence by fine particle passing number 200 sieve, and those relationship is inversely proportionate. 6.The K values of pervious soil are from 10-0 cm/sec to 10-4 cm/sec when degree of compaction by a modified method is from 90 to 95percent. 7.The coarser material is little influenced on the permeability with different density. 8.The increasing rate of permeability with decreasing degree of compaction is more influened by fine pacticle than number 200 sieve. When degree of compaction decrease from 100 percent to 90 percent the K values of SM and GM increase about 20 times but GW increase 6 times only. 9.The effect of compaction by vibration roller is greatly influenced by 6 passes and the increasing rate of the effect is decraased at 8 passes. 10. In order to get the degree of compaction of 95 percent or more, 6 to 8 passes of roller are generall required with 30 cm thickeness of soil for 4.5 ton to 6.5 ton vibration roller and 7 to 8 passes is required with 50cm thickness for 8 to 12 ton roller.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.23-27
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• 2008

In this experiment, growth and yield were affected by planting density, pinching and mowing dates. The greatest growth and yield were obtained at a planting density of $90cm{\times}30cm$. In this planting density, plant grew to the height of 140 cm, with 32 primary, 164 secondary, and 367 tertiary branches per plant. Weight of dry flowers reached 98 kg per 10a with this planting density, which was 40% increased as compared to planting density of $120cm{\times}30cm$. Stem diameter, shoot dry weight, and weight of dry flowers increased by pinching plants as compared to those of non-pinched plants. The greatest weight of dry flowers was obtained in the plant pinched on July 10 with 102 kg per 10a, a 57% increase as compared to the control. Growth and yield were similar for both palnts which were not mowed and mowed on June 10. However, plants mowed on July 10 had significantly smaller plant height, stem diameter and number of branches than the control. An accumulated shoot dry weight was similar for all mowing treatments. The greatest weight of dry flowers and number of flowers per plant were obtained in June 10 mowing treatment with 123 kg and 2,592 flowers per 10a, respectively.

• Geophysics and Geophysical Exploration
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• v.18 no.4
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• pp.171-180
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• 2015

Electrical resistivity of 23 core samples from Ulleung Island at dry or saturated condition has been measured along with dry density and effective porosity, and the relations between the properties has also been discussed. Upper and lower bounds of electrical resistivity at room temperature can be provided by the dry- and saturated-resistivity, respectively. Injecting nitrogen gas to the pore space at the very end of drying process can prevent humid air from getting into the pore space, so that measurement of dry-resistivity can be less affected by humidity in the air. Dry density and porosity have very close correlation; the ratio between increase of porosity and the decrease of density showed distinct relation to the rock types, such that basaltic rocks showed higher ratio while trachytic rocks showed lower. Saturated resistivity showed close correlation to density and effective porosity of the rock sample, while dry resistivity didn't.