• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.23-23
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• 2000

In this study, to determine the optimum fermentation process for the feed production of food wastes and estimate the practical value of fermented feed using kudzu creeper and sawdust as bulking agent. This study considered initial C/N ratio control as the fermentation process variables. The results are summarized as follows. Minimum water contents of byproducts in the fermentation feed production showed 3994(kudzu), 37%( sawdust) at the C/N ratio 25 and 45%(kudzu, sawdust) at the C/N ratio 35. Temperature variations in the fermentation feed production at the C/n ratio 25 indicated 68'C(kudzu), 70'C (sawdust).Optimum condition of consists of fermentation process of water content, C/N ratio and permeability (porous structure of the mixture). For optimum fermentation of gravitationally, dewatered garbage, the proper mixing ratios of kudzu(moisture contents : 17.3%) and sawdust(moisture contents : 13.2%) were 41% and 39%, respectively Major biological reaction in the aerobic fermentation feed production occurred during 12~14hrs

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.7-14
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• 1981

Secondary amines are known as one of the precursors of nitrosamines which are potent carcinogenic compounds for human being and animals. In this study, trimethylamine and dimethylamine contents of salted, hot-air dried and sun dried samples of two commercial fishes, mackerel pike and seerfish were analyzed and quantitatively compared at three different temperature conditions. The formation of both secondary amines was more rapid at$10^{\circ}C\;and\;15^{\circ}C\;than\;at\;2^{\circ}C$. Residual amounts of trimethylamine oxide of salted samples were relatively higher than those of the other samples. Trimethylamine contents of hot-air dried mackerel pike and sun dried seerfish were relatively higher than those in the other samples, while those of salted samples were comparatively lower than those of others. Dimethylamine contents of hot-air dried samples were higher than those of the other samples, whereas those of salted samples were comparatively lower than those of the other samples.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.325-333
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• 1992

An investigation was carried out to find out the effects of long-term application (14 and 28 years) of rice straw, compost and wheat straw on changes in soil chemical and physical properities, aspests of releasing potential nitrogen and nitrogen uptake by rice and maize from fine textured paddy soils with double cropping system in warm temperate area. The result obtained were summarized as follows : 1. The long-term application of organic matters improved plow layer and soil physical properties : bulk density and solid phase were decreased, while porosity and gaseous phase were decreased. 2. Average increment of total carbon per year was 0.0371% and 0.0407% for rice straw and compost, respectively, from 1 through 14 years ; it was 0.0007% and 0.0014% for the rice straw and compost, respectively, from 15 years through 28 years. The average increment of total notrogen per year was 0.0025% and 0.038% for the rice straw and compost, respectively, from 1 through 14 years ; 0.0014% and 0.0024% for the same treatments from 15 through 28 years. 3. $NH_4-N$ and amide-N were high in the soils with wheat straw application for 28 years ; the amino sugar-N in the soils with compost application for 28 years ; amino acid -N in the soils with rice straw application for 14 and 28 years ; and unidentified-N, in the control. 4. The released amount of available nitrogen with the submerged condition was higher at $30^{\circ}C$ than at $25^{\circ}C$ during the incubation. The amount of released available nitrogen at the field was aproximately same as that of $25^{\circ}C$ incubation. However, the released amounts from the incubation and the field were always lower than those extracted with reagents. 5. The amount of nitrogen uptake by rice and maize was highly correlated with available nitrogen extracted with phosphate buffer(pH 7.0). 6. The ratio of yield increase(milled rice) was 17, 12 and 7%, respectively, by application of rice straw, compost and wheat straw for 28 years, and 11% by application of rice straw for 14 years.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.527-534
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• 2012

The adsorption dynamics of activated carbon (AC) and carbon molecular sieve (CMS) beds were studied to recover ethylene from FCC fuel gas. In this study, the FCC fuel gas used consisted of six-component mixture ($CH_4/C_2H_4/C_2H_6/C_3H_6/N_2/H_2$,32:15:14:2:12:25 vol.%). And the breakthrough experiments of adsorption and desorption were carried out. The breakthrough sequence in the AC bed was $H_2$ < $N_2$ < $CH_4$ < $C_2H_4$ < $C_2H_6$ while the sequence in the CMS bed was $H_2$ < $CH_4$ < $N_2$ < $C_2H_6$ < $C_2H_4$. The separation performance of the CMS bed during the adsorption step was lower than that of the AC bed. However, due to the characteristics of kinetic separation, the CMS bed could remove $CH_4/N_2$ as well asthe molecules that are larger than $C_2H_6$, which was not easy to be done by the AC bed. Since it was hard to regenerate the adsorption bed by simple depressurization, vacuum regeneration should be adopted. As a result, the pressure vacuum swing adsorption (PVSA) process, consisting of CMS pretreatment process and AC main process, was suggested to recover ethylene efficiently.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.413-420
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• 1986

This study was attemtped to improve the conventional processing method and to establish the basic data for evaluating the product suitabilities of dried loach. The semidressed raw material were salted in 15% NaCl solution for 15 minutes and dried to contain about 44% of water, and then heated about 10 minutes at $80^{\circ}C$ controlled by microwave (2,450 MHz). The moisture content of monolayer value for the product showed 5.34% and its water activity was 0.28. The optimum relative humidity for the storage was recognized to be from 32% to 44%. The average shelf life around the year of the Nylon-PVC-PE $(40\;{\mu})$ packed product in domestic circulation market was estimated as 207.4 days. In comparison with raw material, the contents of the major amino acids, glutamic acid, alanine and valine in the product were shown to be slightly increased, while the level of lysine, aspartic acid and methionine were slightly decreased. The contents of saturated fatty acids and oleic acid were shown to be slightly increased, while the other fatty acids tended to be slightly decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.289-295
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• 1988

An ordinary paddy variety Hwaseong and a high-yielding variety Samgang were taken under investigation to test the effect of top dressing of newly formulated three compound fertilizers on rice plants for at sprouting heads. The fertilizer formulate used were C. F. I (14-0-14; $NO_3-N$ and $NH_4-N$) and C. F. II (14-0-14; $NH_4-N$ only) and C. F. III (14-0-14 + OM 10%; $NO_3-N$ and $NH_4-N$). A field experiment was conducted on a plot of Gyuam series. The following results were obtained: 1. Effects of compound fertilizers at sprouting heads a. Hwaseong variety exhibited 5-10% yielding increases on the plots with application of 2nd compound fertilizer (I) and (II) compared to straight fertilizer of (I) and (III). Fertilization with 2nd and 3rd compound fertilizers gave the best result when they are done 15 days before heading. A yield increase of 3-5% was achieved when the fertilization was done 20 days before heading in the case of Samgang variety, but no beneficial effect was observed with an application 10 days before heading. b. Rate of barren grains was at the minimum in the compound fertilizer (II) plots of both Hwaseong and Samgang varieties. c. Content of $NO_3-N$ in soils and grain yield appeared to be positively correlated($r=0.618^*$) 2. Effects of heading fertilizers on artificially reduced conditions of soil a. No significant difference in Eh values were measured among reduced paddy soils. The compound fertilizer of (II) presented the best result in yield increases regardless of rice variety. b. Rate of barren grains in both varieties was observed at the minimum on the application of compound fertilizer of (II). c. No great difference of mineral contents was detected among plants from different treatments.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.451-458
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• 2001

The purpose of this study was to evaluate shear parameters on cutting slope of weathered granite soils by using small dynamic cone penetration test on the very moment of its cutting. The results were : On the relations among N$\_$c/, Li, and CEC, the condition of Li＞6%, CEC＞14(meq/100g) corresponds to that of N$\_$c/ values of 2∼30, and 3＜CEC＜14(meq/100g) to N$\_$c/=30∼50. Comparing the smallest penetration depth from two small dynamic cone penetration tests done at 5m below from the top of the slope on April 15th, October 31t. there was a l0cm difference. So we could find out the degree of weathering on the slope. And dividing the difference by 190 days (the whole testing time), we could know it's being weathered 0.052mm each day. The more N. value increases, the more shear parameters(internal friction angle ; $\phi$, cohesion : c) increase at a standard pressure($\sigma$＞32㎪). So the condition of N$\_$c/=2∼50 corresponds to that of $\phi$=27∼50, c=12∼49㎪. From the above testing results, the N$\_$c/ values more correspond to $\phi$ values than c values. In conclusion, this study suggests that on small dynamic cone penetration test a penetration boundary line of 5 centimeters is decided at around Li=4%, CEC=3(meq/100g) which is classified as a strong weathering soil. It also shows that as Li increases CEC increases as well, while N$\_$c/ decreases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.8 no.1
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• pp.15-20
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• 1979

The nitrite and nitrate levels of carrot juice at various temperature and periods were studied. The nitrite level of carrot juice at high temperature increased rapidly as the bacterial level increased. When carrot juice was held at $30^{\circ}C$, nitrite concentration began to decline after 14 hours, although there was no decrease in bacterial population, The nitrate level of carrot juice at high temperature decreased rapidly. The bacteria in carrot juice were supposed to reduce nitrates to nitrites, No increase in nitrite and no decrease in nitrate occured when bacterial growth was prevented by holding the juice at $5^{\circ}C$ or by adding potassium dehydroacetate.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.119-128
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• 2003

The two experiments in this study compared litter nitrogen (N) contents after broiler chicks were raised for 42 days. Experiment I compared litter treated with aluminum sulfate (alum) [Al$_2$(SO$_4$)$_3$ㆍ14$H_2O$] (T$_1$) with nontreated litter (T$_2$) when the broiler chicks were fed the same levels of dietary protein (23% for 0∼3 weeks, 21% for 4∼6 weeks) Experiment 2 compared the alum treated litters of broiler chicks fed high protein diets (T$_3$) having 20.4% protein for 0∼3 weeks and 19.3% for 4∼6 weeks, with lower protein diets (T$_4$) having protein levels of 18.0% for 0∼3 weeks and 17.0% for 4 6 weeks. Each treatment had four replicate cages. As shown in Table 1, T$_1$ had a significantly (P<0.0l) lower pH and significantly (P<0.05) higher total N (TN), NH$_4$-N and inorganic N (IN) than T$_2$. T$_1$ and T$_2$ had similar moisture, organic carbon (OC), NO$_3$-N and organic N (ON). Alum treatment increased available N (AN) significantly (P<0.05) from 13.75$\pm$0.0l mg/g to 14.90$\pm$0.01 mg/g and predicted available N (PAN) significantly (P<0.05) from 15.00$\pm$0.0l to 16.50$\pm$0.02. The C : N ratios were 18.84$\pm$0.40 (T$_1$) and 19.46$\pm$0.10 (T$_2$) while the C : ON ratios were 28.49$\pm$1.15 (T$_1$) and 28.34$\pm$0.20 (T$_2$) although C : N ratios or C : ON ratios did not show any difference between T$_1$ and T$_2$. In Table 2, T$_3$ had significantly (P<0.05) higher moisture, TN, NH$_4$-N, ON and IN than T$_4$, while the pH, OC and NO$_3$-N were similar in both groups. The AN of T$_3$ increased significantly (P<0.05) from 10.99$\pm$0.0l mg/g to 12.98$\pm$0.03 mg/g, while the PAN increased significantly (P<0.05) from 12.39$\pm$0.10 mg/g (T$_4$) to 14.68$\pm$ 0.30 mg/g (T$_3$). The C : N ratios increased significantly (P<0.0l) from 20.07$\pm$0.20 (T$_3$) to 24.40$\pm$0.10 (T$_3$). The C : ON ratios also increased significantly (P<0.0l) from 28.99$\pm$1.15 (T$_3$) to 35.51$\pm$0.20 (T$_4$). These current research results show increased AN contents and PAN contents in alum treated litter or with increased CP levels regardless of alum treatment. However, none of the litters in this study could initially increase mineralization.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1337-1342
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• 2004

To improve the quality of Gulbi, 10% garlic juice (GJ), 10% onion juice (OJ), and 10% garlic and onion juice mixture (GOJ) were added to the brine solution as a wet-salting method. The changes of total volatile basic nitrogen (TVB-N) and trimethyl amine (TMA) production, thiobarbituric acid reactive substance (TBARS) value, and total microbial numbers in Gulbi were analyzed during storage at room temperature for 12 days. The group treated with 10% GOJ showed the lowest values of 88.2 mg/l00 g in TVB-N, 14.13 mg/l00 g in TMA, and 3.1 $\mu$mol/kg in TBARS. The fatty acid profile of Gulbi was analyzed on 5, 15, and 30 days to investigate the effect of GOJ treatment. The group treated with GOJ showed higher C22:6 (9.91%) and C20:5 (4.25%) contents than control (7.37% and 3.71%, respectively), but had lower C18:1 (24.44%) content. The saturated fatty acid content in Gulbi was 32∼35% and the C16:0 (21∼23%) was predominant in it. Oleic acid was major unsaturated fatty acid in Gulbi. The contents of polyunsaturated fatty acids (C18:3, C20:5, C22:6) were decreased after 30 days but increased the saturated fatty acid (C16:0) and monoenes (C16:1 and C18:1). The Gulbi treated with GOJ by brine salting method showed higher DHA and EPA (9.91% and 4.25%, respectively) contents than the control group.