• Korean Journal of Materials Research
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• v.15 no.3
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• pp.161-165
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• 2005

We investigated selective dry etching of GaAs over AlGaAs and InGaP in high density planar inductively coupled $BCl_3/SF_6$ plasmas. The process parameters were ICP source power (0-500 W), RE chuck power (0-30W) and gas composition $(60-100\%\;BCl_3\;in\;BCl_3/SF_6)$. The process results were characterized in terms of etch rate, selectivities of GaAs over AlGaAs and InGaP, surface morphology, surface roughness and residues after etching. $BCl_3/SF_6$ selective etching of GaAs showed quite good results in this study. Selectivities of GaAs $(GaAs:AlGaAs\~36:1,\;GaAs:InGaP\~45:1)$ were superior at $18BCl_3/2SF_6$, 20 W RF chuck power, 300 W ICP source power and 7.5 mTorr. Addition of $(5-15\%)SF_6\;to\;BCl_3$ produced relatively high selectivities of GaAs over AlGaAs and InGaP during etching due to decrease of etch rates of AlGaAs and InGaP (boiling points of etch products: $AlF_3\~1300^{\circ}C,\;InF_3>1200^{\circ}C$ at atmosphere) at the condition. SEM and AFM data showed slightly sloped sidewall and somewhat rough surface$(RMS\~9nm)$. XPS study on the surface of processed GaAs proved a very clean surface after dry etching. It shows that planar inductively coupled $BCl_3/SF_6$ plasmas could be a good candidate for selective dry etching of GaAs over AlGaAs and InGaP.

• Journal of Animal Environmental Science
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• v.4 no.1
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• pp.9-20
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• 1998

This research was conducted to investigate the effects on the amount of nitrogen and phosphorus and the number of maggots in the feces from the experimental pigs fed probiotics additives, and the variance of NH3-concentration(ppm) generated in the experimental pig-pens. The experiment was performed twice in the W-farm(under the condition of sufficient energy and protein in Spring) and B-farm(insufficient energy and protein in Summer). The experiment was designed with 5 treatments (control and 4 treatments according to the kinds of additives used). In the W-farm experiment, 75 three-way crossbred pigs weighing average 38kg were randomized with 3 replications for 102 days. In the B-farm experiment, 105 three-way crossbred pigs weighing average 33kg were randomized with 3 replications for 130 days. The results obtained are as follows: 1. The amount of dry matter, organic matter, nitrogen and phosphorus in the feces was not significantly different among the treatments. But the amount of OM, N and P shows a tendency to be somewhat lowered in the treatment A. On the otherhand, the amount of dry matter was somewhat lowered in the treatment B. The amount of such matters in the W-farm was somewhat lowered than those in B-farm. But there was not significant difference between W-farm and B-farm. 2. On the variance of the number of maggots developed in the pig's feces according to each treatment, the number of maggots in the treatments added probiotics were markedly decreased in comparison with those of the control(T), and it was significantly different(p＜0.01). Especially the decrease in the treatment A and B was much remarkable. 3. The addition of probiotics to the pigs' feeds made the NH3-concentration generated in the pig-pens decrease markedly. especially the NH3-concentration in the treatment A had the highest decreasing ratio among all the treatments. The decreasing ratio of NH3-concentration of the treatments added probiotics as compared to control(T) was 59.1∼80.0%(average 70.3%) in the treatment A, 56.8∼80.0%(ave. 68.5%) in the treatment B and 24.4∼46.0%(ave. 35.0%) in the treatment C and D. On the variance of the NH3-concentration according to the experimental times)seasonal conditions), the NH3-concentration generated in the pig-pens was gradually increased from April to August, on the other hand it was decreased in the September. By the result of this study, it was appeared that the probiotics added to the pigs' feeds made the NH3-concentration decrease in the pig-pens to the extent of safety degree(25 ppm and less) permitted to swine especially in the treatment A and B.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.245-250
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• 1985

In order to increase citric acid productivity. several attempts were made; isolation and characterization of the mutant strain produced citric acid in a high yield, citric acid fermentation in a medium containing relatively higher amount of glucose and citric acid production by the use of semicontinuous ceil recycle system. By the treatment of Candide lipolytica S-109 with NTG, a mutant J-24 was selected as the highest producer of citric acid among the strains formed larger CaCO$_3$ lytic zone. it produced 72g/1 citric acid in 10％ glucose medium. Because mutant J-24 produced 85g/l citric acid and showed 53％ yield in 16％ glucose medium, several factors were adjusted to increase the yield in 16％ glucose medium. 0.8-1.0$\times$10$^{-3}$ P/C ratio, 0.15％ urea, 0.25％ yeast extract were suitable at citric acid production in 16％ glucose medium. Under this condition, J-24 strain produced 93g/l citric acid and showed 58％ yield. Semicontinuous cell recycle system was used to protons the effective production phase, to minimize the product inhibition and to shorten the lag phase. The productivity of semicontinuous cell recycle system was 0.79g/l h while that of batch system was 0.53g/l.h

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.135-146
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• 2005

This study was carried out to investigate the effect of Synechocystis sp. KACC 91007 when added to a pig slurry or pig liquid fertilizer (PLF) on germination index (GI) of Chinese cabbage. The preliminary experiment involved the screening of inoculant levels which were; 0.05, 0.1, 0.2, and $0.3\%$, respectively. The $0.05\%$ level of inoculant was selected based on low phytotoxicity and high GI.. The PLF underwent a 107 day aerobic and anoxic processing conditions. The T-N, T-P, $NH_4$, and $NO_3-N$ concentrations of the untreated pig slurry were; 2,873, 753, 1,441.6, and 16.48 ppm, respectively. Using aerobic processing treatment, the fertilizer value of the PLF was 3,672, 164, 183.87, and 21.97 ppm, respectively. In contrast, the fertilizer value of the PLF processed under anoxic condition was reduced to 1,261, 68, 161, and 16.87 ppm. The GI value of the untreated PLF under aerobic and anoxic processing condition was 83 and $40.4^{*}\%$, respectively. With the addition of the $0.05\%$ microbial inoculant, the GI improved by more than 40 and $50\%$ respectively, when the PLF was processed under anoxic and aerobic conditions. The above findings proved that the aerobic processing of PLF for 107 days was better than anoxic and yielded higher T-N which is a macro-nutrient fertilizer material. Consequently, the addition of $0.05\%$ microbial inoculant resulted to a higher GI of the Chinese cabbage specifically under aerobic processing condition.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.14-20
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• 1996

Growth, nutrient uptake and photosynthesis as affected by submersion of shoot in pickerel weed (Monochoria vaginalis Presl.) were determined. The shoots of pickerel weeds in hydroponic culture were subjected to the submerged or emerged condition at 3- or 5-leaf stage for 8 or 10 days. Under submerged condition, growth in plant height was enhanced, but leaf number, leaf area, fresh and dry weight were reduced compared to those under the emerged condition. Similar responses in growth to submergence were obtained with the pickerel weeds rooted in the soil. Under submergence, chlorophyll content increased during the first 2 days, but thereafter remarkably decreased at 3-leaf stage and after the first 4 days at 5-leaf stage. Compared to the emerged condition, uptakes of $NH_4\;^+$-N, $NO_3\;^-$-N, $P_2O_5$ and $K^+$ were reduced, but uptakes of $Ca^{++}$ and $Mg^{++}$ increased under the submerged condition. Photosynthetic rate of shoot under water, measured by $CO_2$electrode, showed the maximum by 210 ${\mu}$moles $HCO_3\;^-$/g F.W. at the 8th day after submergence(DAS) at 3-leaf stage and 320 ${\mu}$moles $HCO_3\;^-$/g F. W. at 6 DAS at 5-leaf stage. These results indicate that pickerel weeds grow much better when the shoot is air-exposed and are less tolerable to submergence at 3 leaf-stage than at 5-leaf stage.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.55-61
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• 1987

A series of laboratory experiments were carried out to find the effects of soil organic matter contents, soil temperature, pH values, kinds and amount of nitrogen fertilizers on the denitrification-$N_2O$ gas evolution-. The results obtained were summarized as follows: 1. Denitrification rate, amount of $N_2O$ gas evolution, was influenced the order of organic matter contents>soil temperature>pH values>kinds of N-fertilizer>levels of N-fertilizer. 2. The highest dentrification rate was observed in organic matter content of 3.0%, pH values at 6.0 with application of $KNO_3$ at levels of 20 mgN/100g soil. 3. For the evolution of I mole $N_2O$ gas, averaged carbon consumption was obtained as 0.5 mole in all these experiment condition. However, the highest carbon consumption rate was obtained in organic matter contents for 1.0% with application of $(NH_4)_2SO_4$ at levels of 10 mgN/100g soil (1.06 mole) while lowest carbon consumption rate was obtained in organic matter contents for 3.0% with application of $KNO_3$ at levels of 20 mgN/100g soil (0.13 mole). 4. According to Michaelis-Menten's equation, the V/2 values for evolution of $N_2O$ gas was estimated by progress curve. The results obtained was as 550 ug for $(NH_2)_2CO$ and 1100 ug $N_2O/100g$ soil by application of $KNO_3$ in organic matter contents of 1.0% soil. On the other hand, when the application $(NH_4)_2SO_4$ the V/2 values of $N_2O$ gas was obtained as the amount of 490 ug/100g soil while V/2 values of $N_2O$ gas by application of $KNO_3$ was on the linear line in soil organic matter contents of 3.0%.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.33-38
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• 2021

Recently, rollable and foldable displays are attracting great attention in the flexible display market due to their excellent form factor. To predict and prevent the mechanical failure of the display panels, it is essential to accurately understand the mechanical properties of brittle SiN_x thin films, which have been used as an insulating film in flexible displays. In this study, tensile properties of the ~130 nm- and ~320 nm-thick SiN_x thin films were successfully measured by coating a ~190 nm-thick organic nano-support-layer (PMMA, PS, P3HT) on the fragile SiN_x thin films and stretching the films as a bilayer state. Young's modulus values of the ~130 nm and ~320 nm SiN_x thin films fabricated through the controlled chamber pressure and deposition power (A: 1250 mTorr, 450 W/B: 1000 mTorr, 600 W/C: 750 mTorr, 700 W) were calculated as A: 76.6±3.5, B: 85.8±4.6, C: 117.4±6.5 GPa and A: 100.1±12.9, B: 117.9±9.7, C: 159.6 GPa, respectively. As a result, Young's modulus of ~320 nm SiN_x thin films fabricated through the same deposition condition increased compared to the ~130 nm SiN_x thin films. The tensile testing method using the organic nano-support-layer was effective in the precise measurement of the mechanical properties of the brittle thin films. The method developed in this study can contribute to the robust design of the rollable and foldable displays by enabling quantitative measurement of mechanical properties of fragile thin films for flexible displays.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.684-688
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• 2003

The objective of this study was to search for the best strain as a source of L- $\alpha$-glycerophosphate oxidase (GPO) production and to establish the process technology for the purification of GPO on an industrial scale. The GPO was produced by culturing Streptococcus faecium, and purified by ammonium sulfate, DEAE-cellulose and hydroxyapatite chromatography. The relative activity was 60 units/L for 5. faecim ATCC 12755, 65 units/L for 5. faecium ATCC 19634, and 67 units/L for 5. faecium $M_{74}$.LC, respectively. The optimum condition for fermentation was $37^{\circ}C$ for temperature, 300 rpm for stir rate, 0.5 L/min for aeration rate and 17 hours. The main culture medium prepared by the modified AC medium. AC medium consists of 0.1% glucose, 0.2% glycerol, 1.0% tryptone and 1.0% yeast extract, 0.5% $K_2HP0_4$, pH 7.0. The GPO was purified by ammonium sulfate fractionation and ion exchange column chromatography, The yield and purity were 17.2% and 5.3 fold, respectively.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.241-253
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• 2003

Changes in chemical, microbiological quality of pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok in wrap packaging, top sealing, vacuum packaging were evaluated during storage 25$^{\circ}C$, 4$^{\circ}C$, -18$^{\circ}C$ for 5 days. The results were as follows: 1) The cases of chilled and frozen storage, there were small increases in the pH from the first day, with no differences between the different packaging methods, with the exception of the vacuum packaging, which was lower. The pH and Aw of the roasted dodok were lower than those of the other foods. The Aw for all three foods at room temperature significantly decreased in the wrap packaging and top sealing on day one, but the rate of reduction was lower when in chilled storage. The VBN increased with increasing length of storage, and temperatures, but the rate of increase was lower in the top sealing and vacuum packaging. The VBN of roasted dodok was considerably lower than with the other foods. The POV increased significantly on the first day or room temperature storage and the rate or increase was low in chilled End frozen storages, and in the vacuum packaging. 2) SPC of the roasted dodok at room temperature increased significantly within five days of storage. but was inhibited within five days in the vacuum packaging with chilled storage. The SPC of the soy sauce glazed hair tail was low in the top sealing and vacuum packaging when in chilled storage. The coliform of the pan fried oak mushroom and meat. on the fifth day of room temperature storage, was close to hazardous conditions for the wrap packaging. From the third day of chilled storage, few coliform were detected in the pan fried oak mushroom and meat, or the soy sauce glazed hair tail, but not in the vacuum packaging, within five days, for all three foods in frozen storage. The S. spp. had exceeded the standard in the wrap packaging and top sealing with the pan fried oak mushroom and meat on the third day at room temperature, but was not detected in the vacuum packaging within five days, and exceeded the standard in the wrap packaging on the fifth day of chilled storage. S. spp. was not detected in the soy sauce glazed hair tail within five days at all storage temperatures. S. spp. was not detected in the roasted dodok within five days of chilled and frozen storage, but was detected from the third day in the wrap packaging. and the fifth in the top sealing, at room temperature, which exceeded the standard. Sal. spp., V parahaemolyticus, E. coli O157:H7, L. monocytogenes were not detected. 3) The Aw was found to be influenced by storage temperature, period and packaging method, while the VBN was significantly influenced by the storage temperature and period. Regarding the SPC, the pan fried oak mushroom and meat was affected by the storage temperature and period, while the soy sauce glazed hair tail was influenced by the packaging method and storage period. The roasted dodok's microbiological quality was influenced by the method of packaging. The chemical, microbiological quality of home-delivered meals were preserved to be five days in the vacuum packaging, at. chilled and frozen storage.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.1
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• pp.67-80
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• 2021

We analyzed the effect of planting site (elevation: high, middle, low) and temperature condition of orchard on the frost injury occurrence and storage characteristics of persimmon (Diospyros kaki cv. 'Fuyu) fruits under an early fall frost at two orchards, Changwon (A) and Changnyeong (B), Gyeongsangnam-do Korea. Also, the fruits picked at Nov. 5 and Nov. 20 were MA stored to investigate the quality and chilling injury of fruits. On 2-way factor analysis, both planting elevation and orchard factor had not a significant effect on fruit characteristics (weight, firmness, soluble solid), while planting elevation factor did on the skin color (hunter 'a')(p<0.05). A fruit skin coloration at orchard A was faster than that at orchard B. At low elevation of orchard B, 2% fruits were frost injured at harvest season. On LDPE film MA storage with the fruits harvested at Nov. 5 and Nov. 20, the fruits at orchard A had higher fruit firmness than those of orchard B during storage. In addition, the 73% (orchard A) and 85%(orchard B) fruits harvested at Nov. 5 showed no chilling injury 80 days after storage. However, At harvest of Nov, 20 (after incidence of frost), only the 14% fruits of orchard B had no the chilling disorder 80 days after storage, even though 76% fruits at orchard A did.