• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.1
• /
• pp.55-60
• /
• 2000

This experiment was carried out to determine the effect of cutting frequency(3rd and 5th cut) and level of nitrogen fertilization(l50 + liquid manure, 300 and 450kgha) on growth characteristics, dry matter yield and nutritive vaule of reed canarygrass(Pha1aris arundinacea L.), at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon. Plant height of 3rd cutting(79.2cm) was significantly higher than that of 5th cutting(58.0cm). And dry mattter yield of cutting frequency was observed in 3rd cutting(16,902kgPna) and 5th cutting(l7,833kg/ha) As the nitrogen fertilization was increased, DM yield was significantly increased(p<0.05). When the nitrogen fertilization was applied at the level 150 + liquid manure, 300 and 450kg, dry matter yields were 16,5 12, 17,123 and 18,368kg/ha, respectively. The contents of neutral detergent fiber(NDF), acid detergent fiber(ADF) and in vitro dry matter digestibility(1VDMD) were similar among cutting frequency. However, slightly higher NDF, ADF and IVDMD contents were found in 5th cutting, but there was not affected by nitrigen fertilization. Based on the results of this experiment, it were indicated that to 5th cutting and 450kg nitrogen fertilization could be obtained from the increase of dry matter yield and nutritive value (Key words : Cutting frequency, Nitrogen fertilization, Dry matter yield, Nutritive Value, Reed canarygrass)

• Transactions of Materials Processing
• /
• v.31 no.4
• /
• pp.214-228
• /
• 2022

The yield criterion, or called yield function, plays an important role in the study of plastic working of a sheet because it governs the plastic deformation properties of the sheet during plastic forming process. In this paper, we propose a novel anisotropic yield function useful for describing the plastic behavior of various anisotropic sheets. The proposed yield function includes the anisotropic version of the second stress invariant J₂ and the third stress invariant J₃. The anisotropic yield function newly proposed in this study is as follows. F(J₂)+ αG(J₃)+ βH (J₂ × J₃) = k^m The proposed yield function well explains the anisotropic plastic behavior of various sheets by introducing the parameters α and β, and also exhibits both symmetrical and asymmetrical yield surfaces. The parameters included in the proposed model are determined through an optimization algorithm from uniaxial and biaxial experimental data under proportional loading path. In this study, the validity of the proposed anisotropic yield function was verified by comparing the yield surface shape, normalized uniaxial yield stress value, and Lankford's anisotropic coefficient R-value derived with the experimental results. Application for the proposed anisotropic yield function to aluminum sheet shows symmetrical yielding behavior and to pure titanium sheet shows asymmetric yielding behavior, it was shown that the yield curve and yield behavior of various types of sheet materials can be predicted reasonably by using the proposed new yield anisotropic function.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.33 no.3
• /
• pp.185-192
• /
• 2013

This study was carried out to investigate the influence of the seeding dates on the yield and feed value in cultivating Italian rye grass on paddy soil. The field experiment was designed in a randomized block design of 3 repetitions with seeding dates of Oct. 19 (T1), Oct. 26 (T2), Nov. 2 (T3), Nov. 9 (T4), and Nov. 16 (T5) treatments. Plant length, fresh yield, dry matter yield and TDN yield were increased with early seeding dates (p<0.05). Crude protein, Crude fat and crude ash were increased with early seeding dates (p<0.05). On the other hand, NDF, ADF and Crude fiber were decreased with early seeding dates (p<0.05). Total mineral contents were higher in the order of T4 > T3 > T5 > T1 > T2 (p<0.05). The total composition amino acid content was decreased significantly (p<0.05) as the seeding dates delayed. Total free sugar content was highest in T1, whereas the lowest in T5 treatment (p<0.05). Nutrition yields (crude protein, crude fat, amino acid and free sugar) were increased significantly with early seeding dates (p<0.05). The above result indicated that it is favorable to seed soon after rice harvest to increase dry matter yield and nutrition yield of Italian ryegrass in the midlands.

• Journal of Animal Science and Technology
• /
• v.64 no.2
• /
• pp.262-273
• /
• 2022

Under the four-cut system, low-lignin alfalfa (Medicago sativa L.) may extend harvesting intervals improving harvest management flexibility and producing forage products with higher nutritive values. The objective of this study was to compare forage yield and nutritive values of low-lignin and conventional alfalfa varieties when applied to six different harvest schedules in the first (2016) and second (2017) production years. There were 12 treatments of two alfalfa varieties as whole plots and six harvest schedules as subplots. Across harvest schedules, there were four cuttings in two production years. Three harvest intervals including "Standard" (high quality, HQ), "Standard+5-day" (medium quality, MQ), and "Standard+10-day" (high yield, HY) were chosen for the first cutting, and 30-day (HQ) and 35-day (HY) for the second cuttings. The third and fourth cuttings in 2016 were timed near final harvest date and in 2017 occurred at 35-day (MQ) and 40-day (HY). Variety by harvest schedule interaction was not significant, but the whole plot and sub-plot effects were significant. Hi-Gest 360 was consistently higher in nutritive value and with a similar yield as Gunner. Harvest schedules did not consistently differ in forage yield and nutritive values. HS-1 ("Standard" + 35-day + Medium Quality + High Yield) with shorter first two cutting intervals provided lower acid detergent fiber (ADF), neutral detergent fiber (NDF), higher relative feed value (RFV), and similar forage yield compared to other schedules. HS-1 had the highest economic incomes when considering RFV and yield among the six different harvest schedules.

• Transactions of Materials Processing
• /
• v.31 no.6
• /
• pp.351-364
• /
• 2022

The yield criterion, or called yield function, plays an important role in the study of plastic working of a sheet because it governs the plastic deformation properties of the sheet during plastic forming process. In this paper, we propose a modified version of previous anisotropic yield function (Trans. Mater. Process., 31(4) 2022, pp. 214-228) based on J2 and J3 stress invariants. The proposed anisotropic yield model has the 6th-order of stress components. The modified version of the anisotropic yield function in this study is as follows. f(J₂⁰,J₃⁰) ≡ (J₂⁰)³ + α(J₃⁰)² + β(J₂⁰)^3/2 × (J₃⁰) = k⁶ The proposed anisotropic yield function well explains the anisotropic plastic behavior of various sheets such as aluminum, high strength steel, magnesium alloy sheets etc. by introducing the parameters α and β, and also exhibits both symmetrical and asymmetrical yield surfaces. The parameters included in the proposed model are determined through an optimization algorithm from uniaxial and biaxial experimental data under proportional loading path. In this study, the validity of the proposed anisotropic yield function was verified by comparing the yield surface shape, normalized uniaxial yield stress value, and Lankford's anisotropic coefficient R-value derived with the experimental results. Application for the proposed anisotropic yield function to AA6016-T4 aluminum and DP980 sheets shows symmetrical yielding behavior and to AZ31B magnesium shows asymmetric yielding behavior, it was shown that the yield locus and yielding behavior of various types of sheet materials can be predicted reasonably by using the proposed anisotropic yield function.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.2
• /
• pp.56-60
• /
• 2010

Since the forming process involves the strain rate effect, a yield function considering the strain rate is indispensible to predict the accurate final blank shape in the forming simulation. One of the most widely used in the forming analysis is the Hill48 quadratic yield function due to its simplicity and low computing cost. In this paper, static and dynamic uni-axial tensile tests according to the loading direction have been carried out in order to measure the yield stress and the r-value. Based on the measured results, the Hill48 yield loci have been constructed, and their performance to describe the plastic anisotropy has been quantitatively evaluated. The Hill48 quadratic yield function has been modified using convex combination in order to achieve accurate approximation of anisotropy at the rolling and transverse direction.

• Journal of Korean Society of Forest Science
• /
• v.57 no.1
• /
• pp.14-19
• /
• 1982

Fines in high-yield sulfite pulp have much higher water retention value as compared with fines in Stone groundwood pulp. Therefore, they are apt to adhere partially or entirely onto the fiber surface during the paper making. This tendency is greatly enhance with decrease of the pretreated yield and increase of the water retention value of fines. Fines, which adhere onto the fiber surface in paper, contribute to the light scattering of the paper. Accordingly, the specific scattering coefficient of fines in high-yield sulfite pulp is considerably lower than that of fines in stone groundwood pulp, which hardly adhere onto the fiber surface. The fact that high-yield sulfite pulp is inferior to stone groundwood pulp in opacity is explained on the basis of the high degree of swelling of fined in addition to the softening of fiber fraction.

• Korean Journal of Food Science and Technology
• /
• v.49 no.4
• /
• pp.415-420
• /
• 2017

Soybean sprouts are the third-most consumed vegetable in Korea. Several studies on cultivation techniques, including use of medicinal plants extracts, have been performed to enhance the quality and yield of soybean sprouts. The objective of the present study was to investigate the effect of lacquer, a medicinal plant extract, on the yield and nutritional value of soybean sprouts. Linolenic acid content was significantly (p<0.05) increased in the sprouts produced by soaking seeds in lacquer extract diluted with equal volume of water. Lacquer extract significantly increased the flavonoid and phenolic contents (p<0.05). The content of total free amino acids, including ${\gamma}$-aminobutyric acid, was higher in lacquer extract-treated sprouts than in the untreated control. Results of this study suggest that lacquer extract could be used for enhancing the yield and nutritional values of soybean sprouts.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.430-433
• /
• 2005

In this study, weight of evidence(WOE) technique based on the bayesian method was applied to estimate the groundwater yield characteristics in the Pocheon area in Kyungki-do. The ground water preservation depends on many hydrogeologic factors that include hydrologic data, landuse data, topographic data, geological map and other natural materials, even with man-made things. All these data can be digitally collected and managed by GIS database. In the applied technique of WOE, The prior probabilities were estimated as the factors that affect the yield on lineament, geology, drainage pattern or river system density, landuse and soil. We calculated the value of the Weight W+, W- of each factor and estimated the contrast value of it. Results by the ground water yield characteristic calculations were presented in the form of posterior probability map to the consideration of in-situ samples. It is concluded that this technique is regarded as one of the effective technique for the feasibility mapping related to detection of groundwater bearing zones and its spatial pattern.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.1
• /
• pp.49-54
• /
• 2000

A field experiment was carried out to determine the effects of seeding methods and rates on the growth characteristics, forage yield and nutritive value of sorghum X sudangrass hybrid (Sorghum bicolor (L.) Moench, cv. Pioneer 988) grown under application of animal manure in 1995. The application amount of animal manure were 40MT in cattle manure, 30MTha in swine and poultry manure. The methods and rates of seeding treated in this study were drill of 30kg, and broadcast of 30, 60 and 100kgha of seeding rates. The plant height was 180cm, 191cm and 204cm in cattle, swine and poultry manure, respectively. Plant height in the plot of drill was higher by about 15cm than those of broadcast plots. The dry matter(DM) yield was 7.73, 8.87 and 9.80MTha in cattle, swine and poultry manure, respectively. A significant higher forage yield was produced in the plot of drill, compared with broadcast(Pc0.05). DM yields in broadcast of 60kg and lOOkg of seeding rates were higher than that of 30kg of seeding rate of broadcast. However, no significant difference in forage yield was found between 60kg and IOOkg of seeding rates. The average DM yield was 11.16, 6.94, 8.26 and 8.83MTIha in drill(30kg), broadcast 30, 60 and 100kgIMT of seeding rates, respectively. The nutritive value of sorghum x sudangrass hybrid was very similar among treatments. The crude protein yields were 1,010kg in cattle manure, 1,180kg in swine manure, and 1,592kg in poultry manure. The protein yield was significantly high in the plot of drill. In conclusion, seeding by drill was recommended for forage production and protein yield of sorghumxsudangrass hybrid, and proper seeding rates were 30kg in drill and 60kg in broadcast. (Key words : Sorghumxsudangrass hybrid, Seeding rate, Seeding method, Forage yield, Nutritive value, Animal manure)