• The Korean Journal of Ecology
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• 제21권1호
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• pp.65-72
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• 1998

Various effects of simulated acid rain by $HNO_3$ and $H_2SO_4$ with pH 3.2, 4.2 and 5.6 were investigated in Melilotus suaveolens Ledeb, a biennial legume dominating the disturbed and poor soil vegetations. The nitric acid treatment of pH 3.2 resulted in 121% increase of the plant height compared to that of pH 5.6 during early growth, although 17% decrease was detected with the sulfuric acids. During 14 days of treatment, leaf biomass and chlorophyll content increased 168% and 133% with pH 3.2 nitric acid rain but decreased 20% and 38%, respectively, with sulfuric acid rain. Nitrogen content in various organs was also determined after 42 days of nitric acid treatment. It increased 480% and 387% by pH 3.2 and 4.2 in leaves, 212% and 214% in stems and 247% and 249% in roots. However, the same treatment with the sulfuric acid showed a considerable reduction in this content, indicating that the nitric acid was a nitrogen source. Nodule formation assayed revealed 15% decrease with pH 3.2 in contrast to 157% increase in pH 4.2, further suggesting an enhancement effect by the additional nitrogen source. Contrary to this, the nodule formation was reduced up to 43-71% by sulfuric acid rains. Specific nitrogen fixation activities of nodules estimated at pH 3.2, 4.2 and 5.6 nitric acid rain were 36.7, 42.8 and 47.3 ${\mu}mol\;C_2H_4{\cdot}g^{-1}\;fw\;nodule{\cdot}h^{-1}$, while those of sulfuric acid rain exhibited 1 nmol $C_2H_4{\cdot}plant^{-1}{\cdot}h^{-1}$ with pH 3.2, 177 with pH 4.2 and 179 with pH 5.6, yet it increased 2, 115 and 286 respectively corresponding to the three sulfuric acid concentrations. Further implications of the simulated acied rain were also discussed in the study.

• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1374-1388
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• 2007

Three experiments were conducted to investigate the hypothesis that cows grazing on pasture produce the highest proportion of c-9 t-11 CLA in milk fat and no further increase can be achieved through supplementation of diets rich in linoleic acid, such as full-fat extruded soybeans or soybean oil. In experiment 1, 18 lactating Holstein cows were used in a randomized complete block design with measurements made from wk 4 to 6 of the experiment. In experiment 2, three cannulated lactating Holstein cows were used in a $3{\times}3$ Latin square design. Each period was 4 wk with measurements made in the final wk of each period. Cows in both experiments were assigned at random to treatments: a, conventional total mixed ration (TMR); b, pasture (PS); or c, PS supplemented with 2.5 kg/cow per day of full-fat extruded soybeans (PES). In both experiments, feed intake, milk yield, milk composition, and fatty acid profile of milk and blood serum were measured, along with fatty acid composition of bacteria harvested from rumen digesta in experiment 2. In experiment 3, 10 cows which had continuously grazed a pasture for six weeks were assigned to two groups, with one group (n = 5) on pasture diet alone (PS) and the other group (n = 5) supplemented with 452 g of soy oil/cow per day for 7 d (OIL). In experiment 1, cows in PS treatment produced 350% more c-9, t-11 CLA compared with cows in TMR treatment (1.70 vs. 0.5% of fat), with no further increase for cows in PES treatment (1.50% of fat). Serum c-9, t-11 CLA increased by 233% in PS treatment compared with TMR treatment (0.21 vs. 0.09% of fat) with no further increase for cows in PES treatment (0.18% of fat). In experiment 2, cows in PS treatment produced 300% more c-9 t-11 CLA in their milk fat compared with cows in TMR treatment (1.77 vs. 0.59% of fat), but no further increase for cows in PES treatment (1.84% of fat) was observed. Serum c-9, t-11 CLA increased by 250% for cows in PS treatment compared with cows in TMR treatment (0.27 vs. 0.11% of fat), with no further increase for cows in PES treatment (0.31% of fat). The c-9, t-11 CLA content of ruminal bacteria for cows in PS treatment was 200% or more of TMR treatment, but no further increase in bacterial c-9, t-11 CLA for cows in PES treatment was observed. Supplementation of soy oil in experiment 3 also did not increase the c-9 t-11 CLA content of milk fat compared with cows fed a full pasture diet (1.60 vs. 1.54% of fat). Based on these findings, it was concluded that supplementing with feeds rich in linoleic acid, such as full-fat extruded soybeans or an equivalent amount of soy oil, to cows grazing perennial ryegrass pasture may not increase milk fat c-9 t-11 CLA contents.

• The Korean Journal of Ecology
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• 제8권2호
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• pp.69-73
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• 1985

Germination respone to sulfuric acid treatment, temperature, light and underwater condition were experimented for Albizzia julibrissin Durazz. seed. It took 60 minutes to break the dormancy of impermeable seed for the effective sulfuric acid treatment, and temperature sensitivity was decreased by 90 minutes' treatment. The germination rate of the seed was highest, i.e. 96% at 60 minutes acid treatment in a 21。C growth chamber. On the occasion of light sensitivity, the seed was light indifferent. The imbibition rate of seed was higher at 27。C than 21。C and in proportion to the period of acid treatment time. A. julibrissin Durazz. seed were well germinated at underwagter condition.

• The Plant Pathology Journal
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• 제25권2호
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• pp.172-178
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• 2009

To obtain global gene expression profiles of Arabidopsis thaliana by acid stress, seedlings were subjected to low pH stress. Using Affymetrix AH1 chips covering 24,000 genes, we analyzed gene expression patterns. Fifty-four genes were up-regulated, and 38 were down-regulated more than 3-fold after 2 h of acid stress (pH 3.0). Several defense and abiotic stress-related genes were recognized among the up-regulated genes and peroxidase and extensin genes were identified among the down-regulated genes. After 12 h treatment, relatively fewer genes showed changed expression, indicating that plants seem to adjust themselves to this abiotic stress. Most of the up-regulated genes are already known to be involved in abiotic stress responses and pathogen attacks, especially wounding. However, down-regulated genes for the members of extensins and peroxidases are specific to the acid treatment. These results suggest that acid treatment turns on genes involved in stress responses, especially in wounding and turns off genes very specific for the acid stress.

• 펄프종이기술
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• 제43권2호
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• pp.1-8
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• 2011

The presence of high silica in bamboo hinders the use of this material for production of rayon grade pulp. Research has been carried out to overcome this deficiency and improve quality of rayon grade pulp with the modification in pulping and bleaching process. Effect of acid boosted water prehydrolysis, sulphuric acid pre-treatment of unbleached pulp, chlorination stage at lower pH and treatment of bleached pulp with $SO_2$ water were evaluated. Acid boosted water prehydrolysis of chips reduces prehydrolysis time by 50 minutes as compared to water prehydrolysis. Treatment of unbleached pulp with sulphuric acid reduces ash, acid insoluble, silica, calcium and iron contents of the pulp by 56, 31, 82, 84 and 60% respectively. The addition of acid, increase in kappa factor in $C_D$ stage and combination of both were effective in removing silica in the pulp. Treatment of final bleached pulp with $SO_2$ water removes silica to a great extent and improves optical properties of the pulp as compared to $H_2SO_4$ or PAA. Pretreatment of the pulp with acid and modification in the bleaching process can reduce silica substantially and improve the quality of rayon grade bamboo pulp.

• 생명과학회지
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• 제11권5호
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• pp.489-495
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• 2001

대두 발아종 오존수 처리에 의한 배유세포와 산성 인산호효소의 변화에 관해서 전자현미경으로 조사한 결과는 다음과 같다. 산성 인산화효소의 활성은 발달하고 있는 종자 배유의 여러 소기관에 나타났는데, 효소의 활성은 0.5 ppm 오존수를 처리한 후 12시간 배양중에 나타났다. 오존수를 처리한 후 배유가 분화함에 따라 산성 인산화효소의 반응산물은 액포내에 축적되는 것으로 나타나는데, 이것은 산성 인산화효소가 세포간 저장물질의 분해와 이동에 관여하는 것으로 여겨진다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.81-84
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• 2006

This study is intended for how to utilize the recycled fine aggregate which is produced by concrete wastes. It analyzes the quality of the fine aggregate which is reproduced through the acid treatment process, and comprehends the characteristics of mortar using the recycled fine aggregate to review whether it can be put to practical use for concrete. The conclusion of the study are as follows 1. The recycled fine aggregate through the acid treat shows the low rate of absorption and high density. 2. Compared to the mortar made from acid liquid precipitated recycled fine aggregate, using nature water precipitated one reduces the flow. 3. The compressive strength of mortar using recycled fine aggregate tends to be reduced according to the kind of precipitated water. Based on the above results, the recycled fine aggregate through the acid treatment process satisfies the quality standards of the first-grade recycled fine aggregate of KS F 2573 (recycled fine aggregate for concrete) but it is concluded that the recycled fine aggregate through the acid treatment process can not used as fine aggregate used concrete because it has destructive characteristics when the mortar is produced

• 한국식품위생안전성학회지
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• 제10권3호
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• pp.147-153
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• 1995

The ethanol extract from the root bark of Morus alba showed the strongest antimicrobial activity on the growth of almost all the tested microorganisms which were food-borne pathogens and food-related microorganisms. Therefore, fatty acid composition, amino acid composition and shape change of microorganisms treated with the ethanol extract from the root bark of Morus alba were examined. In effects of treatment with the ethanol extract on the fatty acid compositions of B. subtilis, S. aureus and E. coli, fatty aicd compositions such as hexadecanoic acid (16:0) and octadecanoic acid (18:2) of the tested strains were increased but pentadecanoic acid (15:0) heptadecanoic acid (17:0) and acid (16:1) and octadecenoic acid (18:1) of E. coli were decreased. The ethanol extract did not significantly affect the aminn acid composition of the tested strains. Transmission electron micrographs of microorgani는 treated with the ethanol extract exhibited morphological changes that irregularly contracted cell surface in S. aureus and destructed cell walls in B. subtilis and E. coli.

• Journal of Ginseng Research
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• 제33권3호
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• pp.194-198
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• 2009

본 연구에서는 수삼을 식품에 쓰이는 산화 방지제인 ascorbic acid와 citric acid로 처리하여 홍삼을 제조한 후 활성성분인 페놀화합물과 진세노사이드의 추출물내 함량 변화를 HPLC를 이용하여 살펴보았다. 분석결과 citric acid 처리 홍삼에서 esculetin과 quercetin 함량이 무처리 홍삼에 비하여 각각 3.5 배, 2.0 배 증가하였고 ginsenoside 함량 역시 citric acid 처리시의 Rg$_3$, Rd, Rh$_2$ 증가량이 ascobic acid 처리시에 비하여 높았다. 따라서 인삼추출물의 이들 특정활성성분 강화를 위하여는 citric acid 처리가 효과적인 것으로 판단된다.

• 한국물환경학회지
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• 제20권1호
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• pp.72-77
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• 2004

Laboratory studies were carried out to find out the characteristics of humic acid treatment by activated carbon and ionized gas, In order to increase oxidation power of ionized gas for treating organic matter, we used granular activated carbon. By using $UV_{254}$, easy analysis method, we calculated humic acid concentration and $SCOD_{cr}$ concentration. For an initial concentration of humic acid, 10, 50 and 100ppm, the reaction rate constant by $UV_{254}$ was $8.98{\times}10^{-3}$/min, $5.62{\times}10^{-3}$/min and $4.8{\times}10^{-3}$/min respectively due to the same flow rate of ionized gas. When we added activated carbon to the ionized gas for humic acid treatment, the reaction rate constant increased in 4.13, 3.65 and 3.15 times. So, by using activated carbon in treating humic acid by ionized gas, oxidation power of organic matter by ionized gas was increased. The hydrophobic fraction constitutes 98% of organic matter for humic acid at the beginning. After the treatment using ionized gas for humic acid, the hydrophobic fraction decreased by 63~65% and the hydrophilic one increased by 35~37%. So, it was proved that the treatment increased the hydrophilic fraction in organic matter.