• KSBB Journal
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• 제16권4호
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• pp.351-355
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• 2001

호흡율 측정법을 이용하여 하수의 유기물 성분을 ASM No.1에서 제안한 네 가지 성분으로 구분하였다. Ss의 경우 전체 TCOD의 10-16%, Xs의 경우 32-50%, S$_1$의 경우 8-1% 정도를 차지하는 것으로 나타났으며, X$_1$의 경우 2-47% 정도를 차지하는 것으로 관찰되었다. 그리고 이 결과는 외국의 결과와 비교해 볼 때 Ss 성분이 10% 작을 반면 X$_1$ 성분은 10% 정도 큰 것으로 비교되었다. 하수의 미생물 농도를 분석한 결과, active heterotrophic biomass가 TCOD의 10-23% 정도를 차지하고 있었으며, active autotrophic biomass는 검출되지 않았다. 본 실험은 현재 TCOD, SCOD로 구분하는 하수의 유기물 성분을 미생물의 이용 정도를 나타내는 호흡률 측정법으로 세분화함으로서, 본 실험 방법을 이용하여 유기물 분해 과정 및 탈질화 그리고 인 제거 기작에 사용되는 유기물에 대한 정보를 구체적으로 제공할 수 있음을 보여 주었다.

• 대한구순구개열학회지
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• 제13권2호
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• pp.63-76
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• 2010

After introduction of Delaire's basic philosophy, to consider the normal and pathologic anatomy, the role of some structures, such as nasal septum, musculature, and tongue, and some functions, such as dental occlusion or nasal respiration, which play important roles in maxillary and particularly premaxillary growth, on the Korean Journal of cleft lip and palate in 2009, Delaire's primary functional cheilorhinoplasty (FCR) in the unilateral and bilateral cleft lip patients was summarized and introduced according to already published literatures and lectures. This paper will be the second publishment of Delaire philosophy with Korean language.

• 대한치과의사협회지
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• 제53권4호
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• pp.249-258
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• 2015

Snoring and obstructive sleep apnea are the representative sleep disordered breathings, caused by the temporary and repetitive constriction or obstruction of upper airway during sleep. They present with excessively vibratory noise and repetitive cease of respiration. These disorders commonly result in sleep disturbance and the subsequent daytime sleepiness, chronic fatigue. Furthermore, they can cause the serious and extensive complications including increased risk of hypertension, cardiac arrhythmia, cardiovascular disease, cerebrovascular accident, neurocognitive disturbance, traffic and occupational accidents, type II diabetes, childhood growth interruption, awakening headache and finally, relatively increased mortality rate. Because appropriate therapeutic intervention is best way for patients to relieve their symptoms and prevent their possible complications, it is very important for dentists to recognize their own role and responsibility in diagnosis and treatment of these disorders. For this, the present article provides the understanding of the clinical features, possible complications, various treatment modalities, and suitable treatment strategies for snoring and obstructive sleep apnea.

• 한국포장학회지
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• 제28권1호
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• pp.39-46
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• 2022

This study compared the effects of cocopeat and perlite growth media on the storability and quality of sweet pepper fruit stored using modified atmosphere packages (MAP) and carton boxes. The fruits were stored at 8℃ for 35 and 30 days, respectively. Perlite-grown fruits had a significantly lower size at harvest due to the medium's inability to hold plenty of water during the growing stage. Contrary to what is expected for small fruits, the result shows box-stored perlite-grown fruits to have lower weight loss and a longer shelf life than cocopeat-grown fruits, while MAP fruits have indifference. Perlite fruits also had a higher quality in terms of dry matter, soluble solids, and vitamin C, while box-stored fruits had a better visual quality. As expected, respiration and ethylene production rates were high, and fruits had similar after-storage firmness values. Based on the findings, perlite-grown sweet pepper fruits may have a better quality and give preference in a box storage condition.

• 농업과학연구
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• 제38권2호
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• pp.205-212
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• 2011

The potential factors for quality loss of cleaned fresh ginseng and technology to be associated with the improvement of marketability through pre-packaging fumigation were examined. Major microorganisms isolated from fresh ginseng included Botrytis cinerea, and Erwinia sp. Others such as Cylindrocarpon sp., Fusarium spp., Pennicilium spp., Bacillus spp. were also found at relatively low frequency. The bacterial density of vacuum packaged fresh ginseng rapidly increased during simulated marketing. Little correlation between bacterial growth and package swelling was found. In order to improve packaging method of fresh ginseng, pre-packaging treatment of 2-phenylethyl alcohol (PE, 100 uL/L, 4 hr) was examined. The fumigation treatment effectively inhibited the growth of bacteria density and also effective on keeping firmness of ginseng root, especially in cortical portion. The internal gas compositions of plastic container packaged for ginseng were approximately ranged between 6 to 8% $O_2$and 3 to 4% $CO_2$. The $O_2$ level of fumigation treatment was lower than control whereas $CO_2$ level was higher. The upsurge of ethylene evolution I day after simulated marketing was found only in fumigation treatment but it returned to ordinary level at day 2. The sucrose content of 2-PE treatment was significantly reduced at 5 days after simulated marketing but reducing sugars like glucose and fructose remained at higher level. The difference in sugar levels was reduced after 10 days of simulated marketing. The decay of fresh ginseng began at the lateral or fine root, which is weak to physical damage, in general. The epidermis was more damaged. Plastic container packaging with PE fumigation could be an alternative to vacuum packaging, which allows an aerobic environment and prevents anaerobic respiration. Further study of pre-package fumigation is required to improve technology of fresh ginseng marketing.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.404-416
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• 2020

Bacteria that are resistant to high temperatures and alkaline environments are essential for the biological repair of damaged concrete. Alkaliphilic and halotolerant Bacillus sp. AK13 was isolated from the rhizosphere of Miscanthus sacchariflorus. Unlike other tested Bacillus species, the AK13 strain grows at pH 13 and withstands 11% (w/v) NaCl. Growth of the AK13 strain at elevated pH without urea promoted calcium carbonate (CaCO₃) formation. Irregular vaterite-like CaCO₃ minerals that were tightly attached to cells were observed using field-emission scanning electron microscopy. Energy-dispersive X-ray spectrometry, confocal laser scanning microscopy, and X-ray diffraction analyses confirmed the presence of CaCO₃ around the cell. Isotope ration mass spectrometry analysis confirmed that the majority of CO₃^2- ions in the CaCO₃ were produced by cellular respiration rather than being derived from atmospheric carbon dioxide. The minerals produced from calcium acetate-added growth medium formed smaller crystals than those formed in calcium lactate-added medium. Strain AK13 appears to heal cracks on mortar specimens when applied as a pelletized spore powder. Alkaliphilic Bacillus sp. AK13 is a promising candidate for self-healing agents in concrete.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.167-176
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• 2008

Atmospheric N deposition has far-reaching impacts on forest ecosystems, including on-site impacts such as soil acidification, fertilization, and nutrient imbalances, and off-site environmental impacts such as nitrate leaching and nitrous oxide emission. Although chronic N deposition has been believed to lead to forest N saturation, recent evidence suggests that N retention capacity, particularly in the forest floor, can be surprisingly high even under high N deposition. This review aims to provide an overview of N retention processes in the forest floor and the implications of changing C-N interactions for C sequestration. The fate of available N in forest soils has been explained by the competitive balance between tree roots, soil heterotrophs, and nitrifiers. However, high rates of N retention have been observed in numerous N addition experiments without noticeable increases in tree growth and soil respiration. Alternative hypotheses have been proposed to explain the gap between the input and loss of N in N-enriched, C-limited systems, including abiotic immobilization and mycorrhizal assimilation, both of which do not require additional C sources to incorporate N in soil N pools. Different fates of N in the forest floor have different implications for C sequestration. N-induced tree growth can enhance C accumulation in tree biomass as observed across temperate regions. C loss from forests can amount to or outweigh C gain in N-saturated, declining forests, while another type of 'C-N decoupling' can have positive or neutral effects on soil C sequestration through hampered organic matter decomposition or abiotic N immobilization, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1282-1287
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• 2011

The objective of this study was to assess the effect of xylanase on net energy for production, performance, nutrient digestion and gut microflora of broilers fed corn/soy-based diet. Eighty-four day-old male broiler chicks were allocated to two groups receiving two treatments, respectively. Each treatment had six replicate cages with seven broilers per cage. The diets were based on corn and soybean. The treatments were: i) basal diet reduced in apparent metabolizable energy (-0.63 MJ/kg compared to commercial diet specifications); ii) basal diet supplemented xylanase at 4,000 u/kg feed. The experiment used the auto-control, open circuit respiration calorimetry apparatus to examine the heat production and net energy for production. The results revealed that xylanase supplementation did not affect growth performance and diet AME value, but increased $NE_p$ value by 18.2% (p<0.05) and decreased daily heat production per $kg^{0.75}$ by 31.7% (p<0.05). There was no effect (p>0.05) of xylanase supplementation on the ileal digestibility of N and hemicelluloses, but the ileum digestibility of energy was increased by 2% by xylanase supplementation (p<0.05). Xylanase supplementation increased (p<0.05) the count of lactobacillus and bifidobacterial in the caecum.

• 한국지반환경공학회 논문집
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• 제4권3호
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• pp.69-77
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• 2003

대청호에서 WASP5 모델의 매개변수를 산정하고 민감도분석을 실시하였다. 모델의 계산치와 실측치는 값과 그 경향에 있어 근사한 것으로 나타나 이를 통해 대전취수탑 유역의 장래수질예측이 가능하였다. 매개변수의 민감도분석 결과 조류의 최대성장율, 조류의 호흡율, 광소멸계수, 온도 등이 Chlorophyll-a에 가장 큰 영향을 주는 것으로 나타났으며 T-N에 영향을 주는 주된 인자는 용존유기질소 분해율과 온도이며 T-P는 인부하량, 온도, 광소멸계수, 용존유기인 분해율, 조류의 최대성장율 등의 순으로 영향을 받는 것으로 나타났다. BOD에 큰 민감도를 보인 인자는 탈산소계수와 온도였으며, DO는 온도 외의 매개변수에 대한 영향은 거의 없는 것으로 나타났다. 모델의 민감도분석을 통하여 해당 수역에 적합한 입력변수의 민감도에 대한 평가를 하였으며 각 수질항목에 대한 입력변수의 영향에 대한 파악을 통해서 모델의 적용에 주의를 기해야할 해당 입력변수의 구분이 가능하였다.

• ALGAE
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• 제31권1호
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• pp.49-59
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• 2016

Ulva pertusa, a common bloom-forming green alga, was used as a model system to examine the effects of elevated carbon dioxide (CO₂) and temperature on growth and photosynthetic performance. To do this, U. pertusa was grown under four temperature and CO₂ conditions; ambient CO₂ (400 μatm) and temperature (16℃) (i.e., present), elevated temperature only (19℃) (ET; i.e., warming), elevated CO₂ only (1,000 μatm) (EC; i.e., acidification), and elevated temperature and CO₂ (ET and EC; i.e., greenhouse), and its steady state photosynthetic performance evaluated. Maximum gross photosynthetic rates (GP_max) were highest under EC conditions and lowest under ET conditions. Further, ET conditions resulted in decreased rate of dark respiration (R_d), but growth of U. pertusa was higher under ET conditions than under ambient temperature conditions. In order to evaluate external carbonic anhydrase (eCA) activity, photosynthesis was measured at 70 μmol photons m⁻² s⁻¹ in the presence or absence of the eCA inhibitor acetazolamide (AZ), which inhibited photosynthetic rates in all treatments, indicating eCA activity. However, while AZ reduced U. pertusa photosynthesis in all treatments, this reduction was lower under ambient CO₂ conditions (both present and warming) compared to EC conditions (both acidification and greenhouse). Moreover, Chlorophyll a and glucose contents in U. pertusa tissues declined under ET conditions (both warming and greenhouse) in conjunction with reduced GP_max and R_d. Overall, our results indicate that the interaction of EC and ET would offset each other’s impacts on photosynthesis and biochemical composition as related to carbon balance of U. pertusa.