• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.2
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• pp.117-124
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• 2002

This study was carried out to investigate variation of heavy metal contents for feed materials during composting and to evaluate the effect of pre-treatment methods on heavy metal analysis. Dry ashing, $HNO_3-HClO_4$, aqua-regia, HCl reflux, $HNO_3-HClO_4-HF$, autoclaving methods of $HNO_3$, HCl, and $HNO_3(2+1)$ were used as pre-treatment for heavy metal analysis. In analyzing standard material SRM 2781, recovery efficiencies of pre-treatment methods were 50-60% for Cr and Zn, >100% for Ni, and 80-90% for Cd and Cu. Recovery efficiency of dry ashing for SRM 2781 was the lowest. In composting raw material, Cd concentration by autoclaving methods was 3 to 4 times higher than the other methods and recovery efficiency of dry ashing was also the lowest. During composting, Cd content was the highest in autoclaving. Cr and Cu concentrations were the lowest in dry ashing and aqua-regia, respectively. Variation coefficients of Pb and Zn between pre-treatment methods were generally low.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.23-29
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• 2017

This experiment was carried out to compare the productivity and feed value between standard cultivation and organic mixed expeller cake fertilizer cultivation to develop organic cultivation technology except from standard cultivation using chemical fertilizers in the field of forage production. This study was conducted in the rice field of Livestock Research Institute Jacheon-myeon, Gangin-gun Jellanam-do. Organic mixed expeller cake fertilizer consists of 4.0% nitrogen, 65% castor, 30% seeds and 5% fish meal. Sorghum-Sudangrass Hybrids(SX17) was sowed 40kg per hectare on May 25. Test group formation was consisted of a standard group and test treatment. The standard group(Con.) was fertilized chemical fertilizer according to the N-P-K kg/ha, 200-150-150 (basal 100kg, uptake 100kg). Test treatment was carried out organic fertilizer 100%(T1), organic fertilizer 150%(T2) and organic fertilizer 200%(T3) according to the nitrogen content of standard group(Con.). Plant height of harvest time depending on the treatment was that Con was 317cm, T1 was 252cm, T2 was 269cm and T3 was 293cm. Dry matter yield was that Con was 11,386kg/ha, T1 was 6,015kg/ha, T2 was 6,799kg/ha, T3 was 7,627kg/ha. In the test treatment, plant height and dry matter yield increased with increasing fertilizer. Crude protein was the height in Con(7.0%) and Crude protein of test treatment was T1(5.7%), T2(6.3%), and T3(5.1%). As a result of this study, T2 was recommended.

• Journal of Aquaculture
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• v.22 no.1
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• pp.118-121
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• 2009

This experiment was conducted to evaluate the effects of different substrates in rearing tank on growth and body composition of juvenile sea cucumber Apostichophus japonicus. Sea cucumber (average weight 3.6) were randomly distributed at a density of 10 juvenile per tank into nine tanks providing three different substrates including free-substrates, sand and wave-shaped plastic sheet as (shelter). Juveniles were fed with a commercial feed once in every 2 days for 8 weeks. At the end of the experiment, survival of sea cucumber was not affected by the presence of substrates (P>0.05). Weight gain and specific growth rate of sea cucumber reared in the tanks with sand were significantly higher than those of sea cucumber reared in the tanks with shelter and without substrate (P<0.05). Crude protein and crude lipid of whole body in sea cucumber reared in free-substrate tanks were significantly higher than those of juvenile reared in the tanks with other substrates (P<0.05). Higher ash content was obtained in sea cucumber reared in the tanks with sand compared to that of juvenile reared in the tanks with other substrates (P<0.05). The results of this study suggest that growth and proximate composition of whole body of sea cucumber was significantly affected by substrates. Among materials tested, sand may be a proper substrate for sea cucumber culture.

• Resources Recycling
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• v.7 no.3
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• pp.17-26
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• 1998

A study on the recovery of silver and nitric acid in the liquid waste resulted from the mediated electrochemical oxidation(MEO) process was conducted. The removal of silver in the concentrated nitric acid solutions was carried out by the electrodeposition. The removal efficiency more than 98% could be obtained in nitric acid concentrations less than 3 M with the current efficiency of nearly 100%. The experimonts on the evaporation for the recovery of nitric acid were performed as well. At the evaporation factor of 25., the degree of nitric acid recovery in 3.5 M nitric acid solution containing 0.5 to 1.0 mol% NaNO, was 80~90% resulting in 2.8~3.1 M nitric acid. The design factors and operating conditions of the distillation tower were analyzed by using MEH model derived by Maphtali-Sandholm with the throughput of 4 kg/hr for the enrichment of dilute nitric acid solution recovered by evaporation to reuse in the MEO process. The distillation column composed of eleven theoretical stages having the overall tray efficiency of 70% are needed to obtain 1.03 kg/h of 12M nitric acid and 2.97 kg/h of water with feed being introduced to the column at tray 6 from the bottom at the reflux ratio of 0.25, the reboiler with the heat load of 2.7 kW, and the condenser with the cooling load of 0.5 kW.

• Resources Recycling
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• v.7 no.3
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• pp.52-57
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• 1998

The objective of this study was to investigate the effect of cow manure as additive material on the ripening of sewage s sludge for vermistabiJization. The changes of the waste properties by ripening for 50days were observed as a function of the v various mixture ratios of sewage sludge ‘and cow manure. The pH values of the mixture wastes decreased from 7.5-7.67 to 6_ 9~7.2 by the ripening for 50days, and the mixture ratio made dIfferent pH values. The initial value of oxidation-reduction p potential (Eh) of the mixture waste was a negative (-) value indicating an unfavorable condition for earthworm after, but the v values of Eh increased with the opening time. The Increase rate at Eh value was prop$\alpha$rtional to the mixture ratio of cow m manure. The value of alkalinity was also changed into the favorable range for earthworm after 50days except for non-use of 1 the cow manure When the mixture ratio of the cow manure increased from 10% to 30%, the growth of earthworms increased h from 63.7% to 88.3 % tor the survival rate, 265% to 321% for the liveweight increasing rate and 66.7_7% to 91% for hatching f rate of the cocoons. It can be concluded that the proper content of tbe cow manure in the sewage sludge to ensure effective v vermistabilization was over 20%, when the mixture was ripened during 50 days. The quantity of ingestion and 며ectian at 20%-30% was found to be O.15--i.L18g sludge and 0 1l--O.14g solid per capacity earthworm per day, respectively.

• Resources Recycling
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• v.18 no.1
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• pp.38-43
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• 2009

In this study, binderless consolidation processes of ultra foe Si powder, by-products of making high purity poly-Si in the current method, were systematically investigated for use as economical solar-grade feedstock. The average diameter of the silicon powder was $7.8{\mu}m$. The main contaminants of the fine silicon powder were $SiO_2$ type oxide and humidity. The chemical pretreatment using the HF solution was observed to be effective for the improvement of the compactability of the silicon powder and the density ratio and the strength of the silicon powder compacts. The yield of the binder-free consolidation process increased by 20% under a vacuum condition. In as-received state, the silicon powder were not pure enough to be used as solar grade feed-stock material. After the dry chemical treatments, a sufficiently high purity above solar-grade was able to be achieved.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.305-312
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• 2010

The effects of dietary supplementation with Kalopanax pictus branch, leaves, and extracts on performance, proximate composition, pH, total phenol and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, cholesterol and fatty acid composition of chicken meat. Broiler chicks were fed for 5 weeks with a diet containing 5% Kalopanax pictus branch (T1), 2% Kalopanax pictus leaves (T2), and 5% Kalopanax pictus extracts (60% leaves + 40% branch) (T3). T1 and T3 resulted in much better feed conversion than T2. In proximate composition, crude fat of chicken meat was increased, but not signi-ficantly (p>0.05) in Kalopanax pictus-supplemented diets than control diet. Total phenol contents and DPPH radical scavenging activity were significantly increased (p<0.05) by the dietary-supplementation with Kalopanax pictus branch and leaves compared to the control diet. Total and high density lipoprotein cholesterols of treatment groups were higher than the control group, and control group low density lipoprotein cholesterolwas higher than treatment groups (p<0.05). Especially, T3 was significantly (p<0.05) more effective in improving cholesterol compared to other treatment groups. The treatment groups (especially T3) showed significantly higher total fatty acid and unsaturated fatty acid compositions compare to the control group.

• Resources Recycling
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• v.26 no.5
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• pp.54-60
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• 2017

In this study, we investigated the effect of $TiCl_4$ injection time on the Kroll reaction at a given weight ratio of $TiCl_4$ and Mg. The reduction reaction was investigated by measuring the temperature change according to $TiCl_4$ injection time and observing the cross section and appearance of the Ti sponge after the reaction. The temperature increment due to Kroll reaction heat generation was found to be linearly proportional to the $TiCl_4$ feed rate. In the graph of $TiCl_4$ injection time and reduction tank temperature, initial temperature peaks were observed irrespective of the injection conditions. This is interpreted to mean a temporary interruption of reaction due to $MgCl_2$ formation after the initial Kroll reaction. In addition, when the cross section of the sponge was observed, a large amount of spherical Mg particles was observed in $MgCl_2$. We can infer that this is the process of continuously feeding the unreacted Mg surface, so that a continuous Kroll reaction takes place. The sponge appearance showed that the coalescence or growth of the Kroll reacted Ti particles can be controlled by the cooling rate.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.79-88
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• 2011

A total of one hundred twenty pigs were used to investigate effects of silage feeding on pork quality among three breeds (Gagoshima Berkshire, American Berkshire, $LY{\times}\;D$). Pigs weighing about 70 kg of body weight were randomly alloted into three breeds [B (Gagoshima Berkshire), D $(LY{\times}\;D)$, A (American Berkshire) by two dietary treatment [C (commercial diet feed) and T (commercial diet with 80% silage)]. All pigs were fed 67 days of period and then slaughtered to examine meat characteristics. A chemical compositions and physico-chemical characteristics were measured in pork loin. The crude protein content was higher in pig fed diets containing silage than that of the control group. $L^*$ of meat color, appearance, meat color, marbling score and overall acceptability in sensory score of fresh meat were higher in the pigs fed silage (T) than those fed commercial diet (C). In fatty acid compositions of loin, stearic acid and oleic acid were lower in T than C, whereas arachidonic acid, EFA (essential fatty acid) and EFA/UFA (unsaturated fatty acid) were higher in T.

• Food Science of Animal Resources
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• v.42 no.1
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• pp.18-33
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• 2022

Beef contains functional fatty acids such as conjugated linoleic acid and longchain fatty acids. This review summarizes results from studies comparing the fatty acid composition of beef from cattle fed either grass or grain-based feed. Since functional lipid components are contributed through dietary consumption of beef, the fatty acid composition is reported on mg/100 g of meat basis rather than on a percentage of total fat basis. Beef from grass-fed contains lesser total fat than that from grain-fed in all breeds of cattle. Reduced total fat content also influences the fatty acid composition of beef. A 100 g beef meat from grass-fed cattle contained 2,773 mg less total saturated fatty acids (SFA) than that from the same amount of grain-fed. Grass-fed also showed a more favorable SFA lipid profile containing less cholesterol-raising fatty acids (C12:0 to C16:0) but contained a lesser amount of cholesterol-lowering C18:0 than grain-fed beef. In terms of essential fatty acids, grass-fed beef showed greater levels of trans-vaccenic acid and long-chain n-3 polyunsaturated fatty acids (PUFA; EPA, DPA, DHA) than grain-fed beef. Grass-fed beef also contains an increased level of total n-3 PUFA which reduced the n-6 to n-3 ratio thus can offer more health benefits than grain-fed. The findings signify that grass-fed beef could exert protective effects against a number of diseases ranging from cancer to cardiovascular disease (CVD) as evidenced by the increased functional omega-3 PUFA and decreased undesirable SFA. Although grain-fed beef showed lesser EPA, DPA, and DHA, consumers should be aware that greater portions of grain-fed beef could also achieve a similar dietary intake of long-chain omega-3 fatty acids. Noteworthy, grain-fed beef contained higher total monounsaturated fatty acid that have beneficial roles in the amelioration of CVD risks than grass-fed beef. In Hanwoo beef, grain-fed showed higher EPA and DHA than grass-fed beef.