• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.2
• /
• pp.84-89
• /
• 1991

This experiment was carried out to determine the effects of oversowing and other seeding methods (oversowing+ raking, oversowing+ raking+compaction, tillage+ broadcasting+ compaction and tillage + drilling+ compaction) on growth, dry matter and crude protein yield of alfalfa (Medicago satiua L.). The results obtained are summarized as follows:1. Soil pH and soil properties were improved by tillage.2. Establishment of alfalfa was increased with raking and compaction, and more by tillage than by oversowing(P

• Korean Journal of Breeding Science
• /
• v.43 no.4
• /
• pp.311-317
• /
• 2011

This experiment was conducted to give basic information to sprout-soybean breeding and automated sprout production by investigating the effect of seed size on the sprout growth and texture. Twenty cultivars and lines including large and medium soybean, small interspecific cultivars and extra-small wild soybean lines were used. Seeds were cultured for 4 days using small sprout-culturing kits. Hypocotyl length of large Hwanggeumkong, small Pungsannamulkong and Soyoung were longer and wild soybean lines were shorter than other cultivars. Fresh sprout weight and growth rate per unit dry seed weight of wild soybean lines ware increased dramatically and more than other cultivars between 48 to 72 hours after culture. Not only the increasing rate but sprout yield ratio to used dry seed weight showed the negative relationship pattern with seed size. The hardness of hypocotyl in Jangyeubkong, mastication in Taekwang, and cutting force in Eunhakong were the highest as 3,505 g, 1,650 g, and 133 g respectively, and texture values of these traits in wild soybean YWS516 were the lowest. Cutting force of soybean hypocotyl showed the positive relationship pattern with seed size. Breaking force of hypocotyl in large Jangyeobkong was the highest as 83.5g and wild soybean lines were the lowest showing the same pattern as other textural characters.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.4
• /
• pp.639-647
• /
• 2022

The use of flames is essential in cutting, bending, and welding steel during a ship's construction process. While acetylene fuel is commonly used in steel cutting and the manufacturing process in shipyards, the use of propane as an alternative fuel has recently been increasing, due to the lower risk of explosion and propane's relatively low calorific value. However, propane fuel has a relatively slow processing speed and high slag generation frequency, thereby resulting in poor quality. Propylene is another alternative fuel, which has an excellent calorific value. It is expected to gain wider use because of its potential to improve the quality, productivity, and efficiency of steel processing. In this study, the combustion characteristics of propane and propylene fuel during steel plate processing were analyzed and compared. The reduction of greenhouse gases and other harmful gases when using propylene flame was experimentally verified by analyzing the gases emitted during the process. Heat distribution and tensile tests were also performed to investigate the effects of heat input, according to processing fuel used, on the mechanical strength of the marine steel. The results showed that when propylene was used, the temperature was more evenly distributed than when propane fuel was used. Moreover, the mechanical tests showed that when using propylene, there was no decrease in tensile strength, but the strain showed a tendency to decrease. Based on the study results, it is recommended that propylene be used in steel processing and the cutting process in actual shipyards in the future. Additionally, more analysis and supplementary research should be conducted on problems that may occur.

• Journal of Dairy Science and Biotechnology
• /
• v.32 no.2
• /
• pp.131-139
• /
• 2014

The aim of this study was to manufacture Cutting-Gouda cheese and to investigate the change in physicochemical properties of Cutting-Gouda cheese made with Lactobacillus rhamnosus_p1. Lactic acid bacteria were isolated from Gouda cheese ripened for more than 1 year. They were identified as 2 strains of L. rhamnosus, Lactobacillus casei, Lactobacillus curvatus, and Staphylococcus saprophyticus by 16S rDNA sequencing and named L. rhamnosus_p1, L. casei_p2, L. curvatus_p3, L. rhamnosus_p4 and S. saprophyticus_p5. The proteolytic activities of isolated strains against casein were measured using prepared skim milk agar plates. L. rhamnosus_p1 showed the highest proteolytic activity. Cutting-Gouda cheese was made with L. rhamnosus_p1, and its physicochemical properties (moisture, protein, fat, ash and free amino acid content) were measured during ripening periods. Because of the modified atmosphere packaging ($N_2{^-}$), there was no change in moisture, protein, fat, and ash in the experimental group. The total amount of free amino acids in the control and experimental group gradually increased during ripening periods. The sensory evaluation showed that the experimental group was preferable to the control group. This result suggests that L. rhamnosus_p1 has potential to be developed as a new starter for Gouda cheese.

• Korean Journal of Food Science and Technology
• /
• v.23 no.5
• /
• pp.642-645
• /
• 1991

The rheological properties of wheat flours and corn starch and cooking properties of dry noodle in the presence of calcium phosphate hydroxyapatite(Ca-P) were studied. The additive($0.2{\sim}0.8%$) had essentially no effects on farinograms of strong and all-purpose wheat flours, however, they decreased the amylograph pasting temperature and increased the peak viscosity of flours, which was more pronounced in all-purpose flour. The cooking properties of dry noodles in the presence or absence of the Ca-P showed no significant differences, but the cutting forces of cooked noodles were increased by Ca-P at 0.4%. The pasting properties of corn starch in the presence of Ca-P($0.2{\sim}0.8%$) were similar to those of wheat flour. The gelatinization temperature of corn starch by differential scanning calorimeter decreased by $1^{\circ}C$ in the presence of 0.4% Ca-P. The time constant, a reciprocal of rate constant, of corn starch gel was slightly increased in the presence of 0.2 or 0.4% Ca-P.

• Composites Research
• /
• v.23 no.6
• /
• pp.61-66
• /
• 2010

In this paper, the variation of mechanical properties of T800 carbon/epoxy composites according to the forming pressure, which was referred to previous studies on a filament winding process, were investigated. The specimens of all the tests were fabricated by an autoclave de-gassing molding process controlling forming pressure (absolute pressures of 0.1MPa, 0.3MPa, 0.7MPa including vacuum) and water jet cutting after fabricating composite laminates. Various tensile tests were performed for in-plane properties and interlaminar properties were also measured by using Iosipescu test jig. Fiber volume fraction was measured to correlate the property variation and the forming pressure. This properties are expected to be utilized in the design of Type III pressure vessel for hydrogen vehicles which uses the same carbon fiber (T800 carbon fiber) for the filament winding process.

• Journal of Food Hygiene and Safety
• /
• v.26 no.4
• /
• pp.342-348
• /
• 2011

The quality properties of peeled ginger (PG) were investigated during CA storage at different $CO_2$ concentrations. $O_2$ concentration was kept constant at 5% while $CO_2$ of 6%, 14%, 22% and 30% were used. It was found that the weight loss rate tended to decrease with an increase of $CO_2$. In the case of fixed $10^{\circ}C$ storage, the L-value and a-value of the exterior color in treatment increased more than that of control with respect to time, while the b-value of the exterior color and the cutting plane color showed no significant difference. In the exterior color, the results of PG-$25^{\circ}C$ showed similar with PG-$10^{\circ}C$ except b-value of the exterior color which showed not a little change. The cutting plane color did not showed significantly difference in the PG samples between $25^{\circ}C$ and $10^{\circ}C$. Hardness of the PG during storage was found to decrease most severely at 6% of $CO_2$ concentration regardless of storage temperature. The growth of microorganisms during storage of the PG tended to be restrained as $CO_2$ concentration increased. However, microorganisms, when maintained at $25^{\circ}C$ storage, multiplied rapidly to $10^8$ CFU/g within 4 days regardless of concentration.

• Restorative Dentistry and Endodontics
• /
• v.24 no.3
• /
• pp.465-472
• /
• 1999

The aim of this study was to determine the shear bond properties of four dentin bonding systems to internal cervical dentin, and to investigate the effect of the pretreatment for removing smear layer and position of dentin on shear bond strength of dentin bonding agents. The materials tested in this study were consisted of four commercially available dentin bonding systems[Allbond 2(AB), Clearfil Linerbond 2(CL), Optibond FL(OP), Scotchbond Multi-purpose(SB)], a restorative light-cured composite resin[Z100]J and a chelating agent[RC-prep(RC)]. Fifty-six freshly extracted human molars were used in this study. Dentin specimens were prepared by first cutting the root of the tooth 1mm below the cementoenamel junction with a diamond bur in a high speed handpiece under air-water coolant, and then removing occlusal part at pulp horn level by means of a second parallel section, The root canal areas were exposed by means of cutting the dent in specimens perpendicular to the root axis. Dentin specimens were randomly assigned to two groups(pretreated group, not-pretreated group) based on the pretreatment method of dentin surface. In pretreated group, RC was applied to dentin surface for 1minute and then rinsed with NaOCl. In not-pretreated group, dentin surface was rinsed with saline Each groups were subdevided into four groups according to dentin bonding systems. Four dentin bonding systems and a restorative resin were applied according to the directions of manufacturer. The dentin-resin specimens were embedded in a cold cure acrylic resin, and were cut with a low speed diamond saw to the dimension of $1{\times}1mm$. The cut specimens were divided into three groups according to the position of internal cervical dentin. The shear bond properties of dentin-resin specimens were measured with Universal testing machine (Zwick, 020, Germany) with the cross head speed of 0.5mm/min. From this experiment. the following results were obtained : 1. In case of shear bond strength, there was no significant difference among dentin bonding systems in not-pretreated groups, whereas in pretreated groups, the shear bond strengths of AB and of SB were statistically significantly higher than those of CL and of OP. 2. The shear bond strengths of AB and of SB in pretreated groups were significantly higher than those in not-pretreated groups. 3. The shear bond strengths of radicular layer of OP were higher than those of occlusal layer of OP in not-pretreated groups, and of AB in pretreated groups. The shear bond strengths of radicular layer of AB and of CL in not-pretreated groups were higher than those in pretreated group.

• Food Science and Preservation
• /
• v.9 no.1
• /
• pp.36-41
• /
• 2002

We examined the chemical properties of leek and dropwort and prepared the noodles with the dried powder of them, to develope functional processing floods which contain biological active compounds. The groups were divided by the drying methods as follows: hot air drying at 50$\^{C}$ (A), hot air drying after blanching for 30 sec (B), hot air drying after steaming for 2 min (C) and freeze drying (D). We had analyzed the content of vitamin C, total chlorophyll, and phenolic compounds and measured the hunter color values of dried powders individually. The contents of evaluated compounds were higher in A and D than in B and C groups and also the electron donating activity of A and D was stronger than B and C. The cooking properties of noodles prepared with leek and dropwort powder were examined. After cooking, the weight and volume of noodles prepared with powder were lower than those of control The turbidity of noodle soup were increased as the adding ratio was increased. The cutting strength of cooked leek noodles with A and B powder was similar to that of control, in case of dropwort, cooked noodles with D showed similar to that of control. The cutting strength of cooked noodles were decreased as the adding ratio were increased. The electron donating activity of noodles with vegetable powders showed high than that of control The sensory evaluation showed that significant difference between noodles with 2.5 ?/e addition groups and control was not recognized but was recognized between noodles with 5% addition groups and the control.

• Journal of Conservation Science
• /
• v.31 no.2
• /
• pp.105-114
• /
• 2015

In this study, an advanced epoxy putty which was as a multi-purpose restoration material being used to restore missing parts in the artifact preservation treatment process was developed. For the purpose of addressing the issues including the workability issue resulting from high strength, the drooping issue resulting from long hardening time during work process and the issue of contaminating the surface of artifact resulting from stained material on tools or gloves, a property comparison was conducted with existing materials to examine the properties of restoration materials in the form of epoxy putty currently being frequently used. For the purpose of addressing the issues of existing materials and allowing the developed epoxy putty to have similar properties, two types of hardeners with different properties were selected to conduct property experiments. As for the hardeners, mercaptan type hardener and aliphatic amine type hardeners in the total of two types were selected for the development. The result showed that the two types were both in the form of paste and their hardening time of 5-10 minutes were about 3-10 times shorter than that of existing materials, thereby improving the work convenience. In terms of abrasion rate to increase workability, it was improved by about 3 times to allow effective and convenient use. As for the issue of contaminating the artifact surface during the process, white micro-balloon was added as filler to address the issue to reduce the oil ingredient to develop multi-purpose restoration material with low shrinkage & high workability in coloring, light weight and cutting force.