• Proceedings of the Korean Society for Environmental Edudation Conference
• /
• 2005.12a
• /
• pp.138-147
• /
• 2005

In the present study, the middle school students' perception on the environment course was surveyed before and after three different lessons. It was found that most students were taking environment related issues mainly from mass media including internet and broadcasting. The young students were satisfied at practical experiments, but at the same time a few old fashioned experimental programs would not be preferred. Utilization of multimedia such as audio-visual tools was one of the effective tools for the environment class, because it could help to understand even the profound principles of the chemical and physical processes. However, some students did not concentrate on the display, causing frequent disturbance of the class. Since the school for this investigation did not choose the environment as a selective course, practical tools and materials for the experiment should not be sufficient, and thereby a further detailed work must be followed with the students who are taking environment lessons.

• Resources Recycling
• /
• v.31 no.1
• /
• pp.65-77
• /
• 2022

A study was conducted in Korea on the leaching behavior and possibility of recovery of vanadium and other valuable metals from domestic vanadium titanomagnetite (VTM) by direct acid leaching. In this study, a VTM concentrate containing 0.8% V₂O₅ was used, and the ratio of magnetite to ilmenite was calculated as 1.9:1 by using the HSC program. The leaching behavior of vanadium from the VTM was similar to that of iron, and it was affected by the concentration of sulfuric acid and temperature. Further, titanium could be leached in the form of TiOSO₄ at a temperature higher than 75℃. To improve the leaching efficiency of V, Fe, and Ti in VTM, reductive sulfuric acid and oxidative sulfuric acid leaching were performed. When Na₂SO₃ was used as a reducing agent, the leaching rate of vanadium was 80% of that in that case of leaching by sulfuric acid. Similarly, the leaching rate of titanium increased from 20% to 50%. When Na₂S₂O₈ was used as an oxidation agent, most of the vanadium was leached, and the main residue found by XRD analysis was ilmenite. In studies on the possibility of recovering valuable metals, the selective extraction of metals is hardly achieved by solvent extraction from oxidation leaching solutions; however, in this study, Cyanex 923, a solvation extractant from reductive leaching solutions, could selectively extract Ti.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.4
• /
• pp.561-567
• /
• 1993

Twenty Korean native bulls averaging 181 kg body weight were fed a fixed amount (1.5% of live weight) of concentrate and free choice roughage cubes which had four ratios of rice straw and orchard grass hay; 100:0, 85:15, 70:30 and 55:45 on a weight basis. Five bulls were assigned to each treatment and fed for 98 days in a confinement house. Nutrient digestibility and available energy content of mixed rations (40% concentrate and 60% roughage cubes) was determined in a digestion trial with twelve wethers. In vitro dry matter digestibility (IVDMD) and in situ dry matter disappearance of the roughage cubes were also determined. The ratio of grass hay to rice straw did not influence dry matter intake. Significant improvements in body weight gains and feed/gain ratios were obtained as grass hay levels increased. Average daily gain and feed/gain for each treatment was 0.83, 0.88, 0.98 and 0.99 kg; 7.63m 7.59, 6.83 and 6.41, respectively. Digestibility of the nutrients was improved with increasing levels of grass hay in the cubes. The IVDMD of roughage samples having a ritio of 100:0, 85:15, 70:30 and 55:45 between rice straw and orchard grass hay were 31.0, 37.1, 41.8 and 43.4%, respectively. Grass hay improved the IVDMD of rice straw diets in a linear manner up to 30%. In situ dry matter disappearance rate was also increased as the level of orchard grass hay increased.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.10
• /
• pp.1557-1566
• /
• 2007

Ten male crossbred (Thai $Native{\times}Anglo$ Nubian) goats with average live weight of $27{\pm}2$ kg were randomly assigned according to a $5{\times}5$ replicated Latin square design to receive five diets, $T_1$ = concentrate with 0% cassava chip (CC), $T_2$ = 25% CC, $T_3$ = 50% CC, $T_4$ = 75% CC and $T_5$ = 100% CC. Fresh elephant grass (FEG) was offered ad libitum as the roughage. A metabolism trial lasted for 21 days during which liveweight changes and feed intakes were measured. Based on this experiment, there were no significant differences (p>0.05) among treatment groups regarding DM intake and digestion coefficients of nutrients (DM, OM, NDF and ADF), except for $T_5$ (100% CC) which was lowest (p<0.05) in digestion coefficient of CP than $T_1$ and $T_3$. Rumen parameters (ruminal pH, $NH_3$-N and volatile fatty acids), blood urea nitrogen, blood glucose and packed cell volume were similar among treatments. Moreover, rumen microorganism populations were not affected (p>0.05) by cassava inclusion. The amount of N absorption and retention were similar among treatments, except for $T_5$ which tended to be slightly lower. Based on this experiment, it could be concluded that the optimal level of cassava inclusion to replace corn in goat diets was in the range of 25-75% of CC when fed with FEG and it was a good approach in exploiting the use of local feed resources for goat production.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.12
• /
• pp.1732-1737
• /
• 2002

This study was conducted to examine the effect of Leucaena leucocephala-Morus alba-Azadirachta indica (2:1:1) based leaf meal mixture as nitrogen source to partially replace (50%) soybean meal in conventional supplements on the performance of goats. Twelve non-descript female goats were divided into two equal groups in a completely randomized design to receive either the leaf meal mixture based supplement (LMAM) or soybean meal incorporated concentrate (SBM) and wheat straw for ad libitum intake for a two month period. The goats given LMAM and SBM concentrate had similar dry matter intake ($50.2{\pm}1.67g/kg\;W^{0.75}$) and nutrient digestibility. Nitrogen intake and its faecal and urinary excretion were similar irrespective of diets. The balance of nitrogen was positive and comparable ($1.63{\pm}0.08g/d$) in both dietary treatments. The plane of nutrition on both diets was comparable and the digestible crude protein and total digestible nutrients values of the composite diets offered did not differ significantly between the dietary supplements. The serum concentration of enzymes alanine aminotransferase and aspartate aminotransferase were statistically similar in both the groups, while haemoglobin and serum urea levels were significantly (p<0.05) higher in LMAM and SBM treatments, respectively. It was concluded that the leaf meal mixture of Leucaena leucocephala-Morus alba-Azadirachta indica could be used as a vegetable protein supplement to wheat straw based diet of goats.

• Journal of Animal Science and Technology
• /
• v.58 no.2
• /
• pp.9.1-9.5
• /
• 2016

Background: Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep. Methods: The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage). Results: Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d) Conclusion: The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.3
• /
• pp.233-241
• /
• 1988

In order to develop a new type of food source for the effective utilization of fish protein, plastein reaction was applied to improve the functional properties of sardine protein. Conditions necessary for optimal plastein productivity from sardine protein using pepsin, ${\alpha}-chymotrypsin$, protease(from Aspergillus saitoi) and papain were established. Sardine protein concentrate was hydrolyzed with pepsin yielding an approximate degree of hydrolysis of 78.4%. Enzyme induced plastein was optimized at : pH 4 for pepsin, pH 7 for ${\alpha}-chymotrypsin$, pH 5 for pretense and pH 6 for papain : Substrate concentrate 40% for pepsin and ${\alpha}-chymotrypsin$, 50% for pretense and papain : the time of incubation, 24hr : enzyme/substrate ratio, 1 : 100(w/v) incubation temperature, $50^{\circ}C$.

• KSBB Journal
• /
• v.16 no.4
• /
• pp.426-429
• /
• 2001

To utilize sardine protein more effectively, fish meat paste products mixing sardine protein concentrate with pollack frozen meat paste at the ratio 0%, 15%, 20% and 25% were produced, and the change of firmness, sensory evaluation and the properties of amino and fatty acid were investigated. The quantity of sardine protein and it was almost gushed out around one hour at 100$\^{C}$. The firmness of the meat paste product was found as 0.54% and was better when the concentrated sardine protein was added at the ratio 15% and it was much higher than just that of pollack meat paste. In that case, total amino acid was the highest as 90.701 mg/g from the point of view of the amino acid composition. In terms of the fatty acid composition, unsaturated fatty acid of raw and boiled sardine was 61,8634% and 61.9384% each. We could find out that the high value of C$\_$20:5/ and C$\_$22:6/ of raw sardine was 7.2931% and 27.7843%, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.4
• /
• pp.374-381
• /
• 2019

This study was conducted to examine a mixture of plant protein sources as a fish meal (FM) substitute. Two feeding trials were carried out using similar dietary formulations but different FM levels. In Experiments 1 and 2, the basal diets were formulated to contain 65% and 60% of FM, respectively. The other five diets were formulated replacing FM by 10, 15, 20, 25 and 30% with a mixture of soybean meal, wheat gluten and soy protein concentrate. Three synthetic amino acids (lysine, threonine and methionine) were added to the test diet. Groups of fish in experiment 1 ($6.76{\pm}0.03g$) and experiment 2 ($32.5{\pm}0.1g$) were fed one of the experimental diets for 7 and 9 weeks, respectively. Each experiment was carried out in triplicate. There were no significant differences among groups in terms of growth performance, feed utilization, survival or hematological parameters in either experiment. The results indicated that a mixture of soybean meal, wheat gluten and soy protein concentrate, supplemented with three synthetic amino acid, can replace fish meal by up to 30% in diets for juvenile olive flounder.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.7
• /
• pp.983-987
• /
• 2003

Malpura and Kheri ewes (76) in their late gestation, weighing $34.40{\pm}0.95kg$ were randomly selected and divided into 4 groups of 19 each (G1, G2, G3 and G4). Ewes in all the groups were grazed on natural rangeland from 07.00 h to 18.00 h. Ewes in G1were maintained on sole grazing while ewes in G2, G3 and G4, in addition to grazing received concentrate mixture at the rate of 1% of their body weight during late gestation, early lactation and entire last quarter of pregnancy to early quarter of lactation, respectively. The herbage yield of the community rangeland was 0.82 metric ton dry matter/hectare. The diet consisted of (%) Guar (Cyamopsis tetragonoloba) bhusa, (59.2), Babool pods and leaves (17.2), Bajra (Pennisetum typhoides) stubbles (8.8), Doob (5.3), Aak (4.2) and others (5.3). The nutrient intake and its digestibility were higher (p<0.01) in G2, G3 and G4 as compared to G1 because of concentrate supplementation. The intakes of DM ($g/kg\;W{^0.75}$), DCP ($g/kg\;W{^0.75}$) and ME ($MJ/kg\;W{^0.75}$) were 56.7, 5.3 and 0.83; 82.7, 12.2 and 1.16; 82.7, 12.1 and 1.17 and 83.1, 12.3 and 1.18 in G1, G2, G3 and G4, respectively. The per cent digestibility of DM, OM, CP, NDF, ADF and cellulose was 57.9, 68.8, 68.7, 52.3, 37.5 and 68.4; 67.6, 76.1, 82.3, 60.6, 44.5 and 73.4; 67.6, 76.1, 81.5, 60.6, 44.8 and 74.5 and 67.6, 76.1, 82.3, 60.6, 44.7 and 73.3 in G1, G2, G3 and G4, respectively. The nutrient intake of G2, G3 and G4 ewes was sufficient to meet their requirements. The ewes raised on sole grazing lost weight at lambing in comparison to advanced pregnancy. However, ewes raised on supplementary feeding gained 1.9-2.5 kg at lambing. The birth weight of lambs in G2 (3.92) and G4 (4.07) was higher (p<0.01) than G1 (2.98), where as in G1 and G3 it was similar. The weight of lambs at 15, 45 and 60 days of age were higher in G2, G3 and G4 than in G1. Similarly, the average daily gain (ADG) after 60 days was also higher in G2, G3 and G4 than in G1. The milk-yield of lactating ewes in G2, G3 and G4 increased up to 150-250 g per day in comparison to G1. The birth weight, weight at 15, 30, 45 and 60 days, weight gain and ADG at 30 or 60 days was similar both in male and female lambs. It is concluded from this study that the biomass yield of the community rangeland is low and insufficient to meet the nutrient requirements of ewes during late gestation and early lactation. Therefore, it is recommended concentrate supplementation at the rate of 1% of body weight to ewes during these critical stages to enhance their production performance, general condition as well as birth weight and growth rate of lambs.