• Environmental Mutagens and Carcinogens
• /
• v.15 no.2
• /
• pp.115-121
• /
• 1995

Bacterial mutagenicity of shellfish or canned products of red-muscle fish affected by hot-airdry processings and/or during storages was investigated by Ames preincubation method. Mussel (Mytilus edulis) and surf clam (Tapes japonica) dried under either 40$\circ$C, 50$\circ$C or 60$\circ$C until remained about 25 % water content was stored at 4$\circ$C or 25$\circ$C for 6 months. Commercially available canned product of pacific saury (Cololabis saira) and mackerel saury (Scotnberjaponicus), whose producer or date of manufacture was identical each other, was stored at 25$\circ$C for 6 months. Mutagenic substances from sample (25 g dry weight) were extracted and purified for mutagenicity assay against S. typhitnurium TA98 by the simultaneous distillation extraction (SDE) method (Lee et al. 1955). Mutagenicity of sample was expressed number of revertant per 25 g dry sample. Number of revertant from unheated mussel sample was appeared to be 135, relative to 22 from unheated surf clam sample. Mutagenicity of both shellfish was strongly affected by heat treatment, but a lesser extent by storage conditions, even at 25$\circ$C for 6 months. Revertants of the mussel sample dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C was found to be 227, 779, and 883, respectively. Similar, but lower, mutagenicity was observed from the sample of surf clam dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C than mussel. Mutagenicity of canned pacific saury and mackerel samples was not influenced by storage conditions. Number of revertant from pacific saury was 175 which was relatively higher than 5 from mackerel. Mutagenicity of fresh pacific saury and mackerel samples was significantly higher than that of their counterparts from canned products. These results indicate that mutagenicity of the shellfish was affected by heat treatment (40$\circ$C, 50$\circ$C, or 60$\circ$C) used for drying process, but not much by storage for 6 months at 4$\circ$C or 25$\circ$C and the mutagenicity of canned products of red-muscle fish was not influenced by storage, even at 25$\circ$C for 6 months.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.12
• /
• pp.1760-1766
• /
• 2009

Physical properties of Yukwa base extruded with glutinous rice flour, rice flour, defatted soy flour, and salt using an twin-screw extruder were investigated. The ingredients were extruded at various moisture contents (16-18%), screw speeds (300 & 400 rpm) at 43.4 kg/hr feed rate. Length and specific volume of Yukwa base increased with decreasing moisture contents. Hunter's color L* values of Yukwa base was higher whereas $a^*\;and\;b^*$ values were lower with increasing moisture content. Water absorption index of Yukwa base increased with increasing moisture contents. X-ray diffraction of Yukwa base showed B type moisture content of 16% and 17% while it showed A type moisture content of 18%. Degree of crystallinity and breaking strength of Yukwa base were the lowest in the moisture content of 16% while the lowest value for hardness was found in the moisture content of 16% and of 17% with screw speed 400 rpm for all samples. In the microstructure of cross section of Yukwa base, air cell size was larger and cell wall was thicker as moisture content increased. The sensory evaluation of the Yukwa base showed that color and flavor were not significantly different among samples, while taste, appearance, mouth feel, and overall preference were higher as moisture contents decreased.

• Journal of Bio-Environment Control
• /
• v.12 no.4
• /
• pp.200-206
• /
• 2003

Pleurotus eryngii(King oyster) is one of the most promising mushrooms produced on the domestic farms. The quality as well as quantity of Eryngii is sensitively affected by micro climate factors such as temperature, relative humidity, $CO_2$ concentration, and light intensity. To safely produce high-quality Eryngii all the year round, it is required that the environmental factors be carefully controlled by well designed structures equipped with various facilities and control systems. At the commercial mushroom cultivation house(A,B), this study was carried out to find out reasonable range of each environmental factor and yield together with economic and safe structures influencing on the optimal productivity of Eryngii. this experiment was conducted for about two-month from Nov. 11, 2002 to Dec. 30, 2002 in Eryngii. cultivation house-A, B. Ambient temperature during the experiment period was not predominantly different from that of a normal year. The capacity of the hot water boiler and the piping systems were not enough. Maximum air temperature difference between the upper and lower growth stage during a heating time zone was about 2~3$^{\circ}C$. The max. and min. relative humidity were ranged approximately 60~100%, and average relative humidity was ranged approximately 80~100%. And $CO_2$concentration increased until maximum 1,600~1,800 ppm with the passing growing period. The illuminance in cultivation house was widely distributed from 20lx to 160 lx in accordance with position, and it was maintained lower than the recommended illuminance range 100~200 lx. The average yield per bottle was about 67~85g. But the optimal productivity will be evaluated by considering the quality and quantity of mushroom production, energy requirements, facility construction and management cost, etc.

• Journal of Bio-Environment Control
• /
• v.19 no.4
• /
• pp.189-194
• /
• 2010

A multi line electric tube consisted of XL pipes contained with 2~4 hot wires and water in it. The specification of one meter length multi-line electric tube was investigated and the proper number in the multi-line electric tube was determined. A multi line electric tube with three hot wires were found to be the most efficient for the media heating control system. Temperature rise of medium in the rice hulls media was faster than that in the perlite media, showed better insulation effect of rice hulls media. Temperature rise of medium with mulching on the top of the bed was faster than without mulching, resulted in the beneficial effect of temperature rise with mulching. The regression model for the rice hulls media with mulching air temperature of $5^{\circ}C$ were a = -0.1458 and b = -0.1088. Using the model, the temperature rise of medium during low temperature season can be predicted for the various media according to the different depths.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.7 no.3
• /
• pp.229-240
• /
• 1987

Carbonation of concrete is one type of a chemical process. The reaction mechanism is very complex for the case when low-calcium fly ash and blast furnace slag is added. When fly ash and blast furnace slag is used as an admixture in concrete, they improve compressive strength in the long term, permeability and chemical resistance of concrete by a pozzolanic reaction and latent hydraulic property. On the other hand, the pozzolanic reaction of fly ash and latent hydraulic property of the blast furance slag leads to a reduction of the alkalinity of the concrete. It has been pointed out that this will accelerate the carbonation of the concrete and the corrosion of reinforcement steel embedded in the concrete. In order to clarify the effect of fly ash and blast furance slag on the carbonation of concrete, an accelerated carbonation testing of concrete was carried out by varying the conditions of concrete and the initial curing period in water. The test results of accelerated carbonation were compared to the carbonation test results of concrete stored for 15 years in open air, but protected from rain. As a result, the equation for the rate of carbonation based on compressive strength of concrete was proposed.

• Journal of Life Science
• /
• v.19 no.10
• /
• pp.1468-1477
• /
• 2009

The comparative effects of the fibrinolytic, and tyrosinase inhibition activities and electrophoretical protein patterns with freeze-drying silkworm powder (FDSW), heating-drying silkworm powder (HDSW) and fermented silkworm powder by Bacillus subtilis or Lactobacillus hilgardii were investigated. When total protein patterns of FDSW, HDSW, both fermented SW, were analyzed by native- and SDS-polyacrylamide gel electrophoresis (PAGE), there were slightly varietal differences in electrophoretical protein patterns. Major minerals of FDSW and HDSW were K, Ca, Mg, and Zn. Major compositional amino acids of FDSW and HDSW were glycine, alanine, glutamic acid, aspartic acid, and serine. Major fatty acids of FDSW and HDSW were linolenic acid, oleic acid, and palmitic acid. Fibriolytic activity was the highest in the fermented FDSW by 5% B. subtilis among the various samples. Tyrosinase inhibition activity was higher in the water and 70% methanolic extract of FDSW than in HDSW. DPPH radical scavenging activity was slightly stronger in HDSW than in FDSW. In addition, DPPH radical scavenging activity was higher in FDSW or HDSW fermented by L. hilgardii than that fermented by B. subtilis, however, all samples exhibited a relatively low activity compared to the butylated hydroxytoluene (BHT). These results may provide the basic data to understand the biological activities of fermented SW.

• The Korean Journal of Malacology
• /
• v.28 no.4
• /
• pp.313-319
• /
• 2012

Mass production method on artificial seedling production of hard clam Meretrix petechialis was developed indoor culture system. Spawning of adult clam (SL $65.8{\pm}8.4mm$) was induced using the combined method of air exposure and water temperature raising. The fertilized eggs were developed to D-shaped larvae after 17.7 hours at $27^{\circ}C$ and hatching rate was 6.1%. Shell length (SL) of D-shaped larvae was measured to be $131.4{\pm}2.6{\mu}m$ and thereafter the larvae grew to the settled spats with SL $190.2{\pm}7.5{\mu}m$ in 4 days. Estimated survival rate of settled spats was 48.1%. Spat collection on 130,000 spats with SL $0.19{\pm}0.01mm$ performed conducted by sand bottom circulation filtering method. Collected spats grew up to $3.1{\pm}0.8mm$ in 46 days, $6.6{\pm}1.8mm$ in 87 days, and $10.5{\pm}0.9mm$ in 114 days. The relative growth between SL and shell height (SH) was calculated to be SH = 0.8501SL + 0.0196 ($R^2=0.9987$) during the whole spat period. During spats rearing, they were suffered from one time of mass mortality at SL 3.1 mm, but 51,000 spats were finally survived with the rate of 39.2% at 114 days of spat rearing in indoor tank system.

• Proceedings of KOSOMES biannual meeting
• /
• 2007.11a
• /
• pp.97-102
• /
• 2007

The piggery wastewater is the major source of the water pollution problem in the rural area. The treatment alternatives for piggery wastewater are limited by the characteristics of both high organic and nitrogen(N) content. In order to investigate an efficient N removal system, the thermophilic aerobic digestion process was examined. The experiment was investigated organic and nitrogen removal efficiency at various HRTs and air supply volume. The results of semi-continuous experiment indicated that a higher removal of the soluble portion of COD was achieved with the longer HRTs. However, the inert portion of COD in piggery wastewater was not much changed by thermophilic aerobic digestion. In addition, with the higher HRT of 3 days, up to 79% of NH4-N removal efficiency was achieved. Lower the HRTs, a decrease of NH4-N removal was founds. The gas samples from the lab reactor were analyzed along with the N content in influent and effluent. The N2O formation in our system indicates a novel aerobic deammonification process occurred during the thermophilic aerobic digestion. Both N02 and N03 were not presented in the effluent of thermophilic aerobic digester. With the HRT of 3 days, 36.4% of influent N(or 57.5% removal N) was aerobically converted to N2O gas. The ammonium conversion to N2O gas significantly decrease to 4.5% at low HRT of .05 day..

• Journal of Digital Contents Society
• /
• v.19 no.9
• /
• pp.1739-1749
• /
• 2018

We propose a marine observation system using existing light buoys to observe various marine information of marine locations. Our proposed ocean observation system is composed of the existing standard light buoy type and can be easily connected to the light buoy. The proposed marine observation system measures the mean wave height, maximum wave height, mean wave height and water temperature measured in the ocean. Besides, it can measure the air pressure, temperature, wind speed and wind speed in real time. In order to measure important peaks in marine observations, 2200 peak data are collected for 10 minutes, and the collected data are subjected to spectral analysis to extract significant wave and wave period data. The developed system removes the noise by using the filter because the marine observation system attaches to the light buoy. We compare and analyze the measurement data of the existing proven floating marine observation system and the standard equivalent system developed. Also, it is proved that the data of the standard type backbone ocean observation system developed through the comparative experiment is similar to that of the existing ocean observation system.

• Korean journal of applied entomology
• /
• v.20 no.1 s.46
• /
• pp.6-14
• /
• 1981

The effect of heat or chemotherapeutant treatment on the mosaic virus infected garlic(Allium sativum L.) scales and that of chemotherapeutant added to the culture medium were summarized as following. The treatment of the virus infected garlic scales at $37\~57^{\circ}C$ for 35 days to one hour in water or in air shelved no effort of inactivating the virus. Although treatment of the garlic scales at $62\~72^{\circ}C$ for 90 to five minutes reduced the mosaic symptom on the leaves of the garlic plants grown after the heat treatment, it reduced the growth vigor of the plants so greatly that complete inactivation of the virus in garlics was not feasible. The mosaic symptom on the leaves of garlic plant was reduced when the infected garlic scales were grown after 24 hours soaking in $10\~50\;ppm$ Malachite Green, 2,4-Dichlorophnoxy Acetic Acid, or in $20\~100\;ppm$ Quinhydron. These chemotherapeutants, however, inhibited the growth of garlic plant at the high concentration. Garlic scales soaked in $10\~50\;ppm$ Naphthyl Acetic Acid showed the least mosaic symptom without its complete extiction on the garlic leaves. When incorporated into the modified Murashige-Skoog's medium, $0.5\~l.5\;ppm$ Naphthyl Acetic Acid could inactivate the mosaic virus in newy developed garlic plants showing no mosaic symptom on the leaves, no inclusion bodies and intact nuclei in the leaf tissue cells.