• Microbiology and Biotechnology Letters
• /
• v.47 no.4
• /
• pp.621-629
• /
• 2019

In this study we attempted to screen bacteria and fungi that generate electricity while treating wastewater using optimized double-chamber microbial fuel cell (MFC) system parameters. Optimization was carried out for five best exoelectrogenic isolates (two bacteria and three fungi) at pH values of 6.0, 7.5, 8.5, and 9.5, and temperatures of 30, 35, 40, and 45℃; the generated power densities were measured using a digital multimeter (DT9205A). The isolates were identified using molecular characterization, followed by the phylogenetic analysis of isolates with known exoelectrogenic microorganisms. The bacterium, Proteus species, N6 (KX548358.1) and fungus, Candida parapsilosis, S10 (KX548360) produced the highest power densities of 1.59 and 1.55 W/m² (at a pH of 8.5 and temperatures of 35 and 40℃) within 24 h, respectively. Other fungi-Clavispora lusitaniae, S9 (KX548359.1) at 40℃, Clavispora lusitaniae, S14 (KX548361.1) at 35℃-and bacterium-Providencia species, N4 (KX548357.1) at 40℃-produced power densities of 1.51, 1.46, and 1.44 W/m², respectively within 24 h. The MFCs achieved higher power densities at a pH of 8.5, temperature of 40℃ within 24 h. The bacterial isolates have a close evolutionary relationship with other known exoelectrogenic microorganisms. These findings helped us determine the optimal pH, temperature, evolutionary relationship, and exoelectrogenic fungal species other than bacteria that enhance MFC performance.

• Journal of Animal Science and Technology
• /
• v.46 no.1
• /
• pp.55-60
• /
• 2004

The effects of concentrate to roughage ratios on duration and frequencies of rumination and chewing in Hanwoo steers were determined. Five Hanwoo steers fitted with rumen fistula were used to evaluate the effects of concentrate to rice straw ratio on eating and ruminating behavior. Experimental diets were formulated with different concentrate to rice straw ratios(50 : 50, 60: 40, 70: 30, 80: 20, 90: 10). When level of roughage feed was increased by 10, 20, 30, 40 to 50% of total dry matter of the diet, total chewing time was increased linearly from 286.99, 321.09, 390.29, 406.63 to 423.30 min/d, which was mainly due to increased ruminating time from 204.91 to 342.80 min/day. However, the level of roughage did not affect eating time. The number of chews per day for rumination and number of chews per rumination were significantly decreased(p < 0.05) as roughage level was increased. In summary, the duration and frequencies of rumination in Hanwoo increased with increased rice straw level.

• The korean journal of orthodontics
• /
• v.47 no.4
• /
• pp.215-221
• /
• 2017

Objective: This questionnaire study aimed to estimate the overall frequencies of positive perception towards orthodontic treatment among adults categorized according to age, sex, and area of living, and to identify barriers or negative perceptions preventing them from receiving orthodontic treatment. Methods: The participants included 598 adults aged over 20 years (230 men and 368 women) who visited the Dental Hospital of Seoul St. Mary's Hospital. The participants' opinions regarding their consideration of receiving orthodontic treatment were recorded using a specially designed questionnaire. Results: The overall rate of positive perception towards orthodontic treatment was 48.5%. Compared to adults in their 20s (63.2%), those in their 40s and 50s had a lower percentage of interest in orthodontic treatment (46.2% and 45.1%, respectively; p < 0.05). Overall, women (52.2%) had a higher rate of interest than did men (42.6%; p < 0.05). The area of living had no effect on the percentage of interest. The order of priority of chief complaints differed according to age: protrusion for those in the 20s and 30s, and spacing for those in the 40s to 60s. Overall, the main reason for not seeking treatment was the treatment fee. Respondents aged over 40 considered themselves "too old" for orthodontic treatment. Conclusions: The middle-aged had a relatively high percentage of interest (above 45%) in orthodontic treatment. However, demographic characteristics were not significantly associated with the positive interest. These results highlight the need for educating the middle-aged about the limitations and possibilities of orthodontic treatment to increase its acceptance.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.4
• /
• pp.49-55
• /
• 2004

Properties of concrete using low heat portland cement is different from using ordinary portland cement and temperature of aggregate can be expected to have an important influence on its properties. In this study, experiment by setting up 5 levels (40, 30, 20, 4, $-2^{\circ}C$) by temperature of aggregate for evaluation properties of concrete using low heat portland cement was conducted. The experiments include slump test, air content test, change of slump, change of air content and compressive strength of concrete test. As the result of experiments, slump and air content was decreased by increasing temperature of aggregate. But it was not exceeding it's limit. Change of slump and air content was rapidly decrease by decreasing temperature of aggregate. At early age, compressive strength was influenced by the temperature of aggregate.

• Journal of applied mathematics & informatics
• /
• v.7 no.3
• /
• pp.995-1004
• /
• 2000

In this paper we shall give a slight generalization of J. Vukman's Theorem. And show from the result that the image of a continuous linear Jordan derivation on a noncommutative Banach algebra A is contained in the radical under the condition [D(x),x]E(x) ${\in}$ rad(A) for all $x{\in}A$ . And we show some properties of the derivations on noncommutative Banach algebras.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.10 no.1
• /
• pp.35-40
• /
• 1980

The purpose of this survey was to reveal a incidence of dens invaginatus in the max. illary incisor region. The material was 1671 sets of full mouth intraoral standard films, which was taken from the patients visiting for the routine check at the Infirmary of College of Dentistry, Kyung Hee University. The following results were obtained; 1. The incidence of dens invaginatus was 14.90 and that of slightly dilated dens invaginatus was 9.46%. 2. The incidence of dens invaginatus showed no difference between male and female. 3. Most of the dens invaginatus occurred in the maxillary lateral incisors (93.53%) and a few in the maxillary central incisors (6.46%) showed slight invagination. 4. Among the cases with dens invaginatus, over a half (53.4l%) showed bilateral occurrence. 5. Comparatively rare cases, i.e. bilateral dens invaginatus of the maxillary central incisors, unilateral double dens invaginatus of the maxillary lateral incisor, and bilateral dens invaginatus of the maxillary lateral incisors, one side double and one side single, were reported.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.1
• /
• pp.35-40
• /
• 2004

This study is performed to examine the physical and mechanical properties of eco-concrete using soil, natural coarse aggregate, excellent soil compound and polypropylene fiber. The test result shows that mass loss ratio is decreased with increasing the content of coarse aggregate and excellent soil compound. The compressive and flexural strengths are increased with increasing the content of coarse aggregate, excellent soil compound and polypropylene fiber. The coefficient of permeability is decreased with increasing the content of coarse aggregate and excellent soil compound, but it is increased in 0.2% polypropylene fiber content. The lowest coefficient of permeability is showed in $5.066\times 10^{-9}$cm/s. These eco-concrete can be used for farm road.

• International Journal of Oral Biology
• /
• v.46 no.3
• /
• pp.140-145
• /
• 2021

This study aimed to develop Lautropia mirabilis-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the sequence of DNA-directed RNA polymerase subunit beta gene. The PrimerSelect program was used in designing of the qPCR primers, RTLam-F4 and RTLam-R3. The specificity of the qPCR primers were performed by conventional PCR with 37 strains of 37 oral bacterial species, including L. mirabilis. The sensitivity of the primers was determined by qPCR with the serial dilution of purified genomic DNA of L. mirabilis KCOM 3484, ranged from 4 ng to 4 fg. The data showed that the qPCR primers could detect only L. mirabilis strains and as little as 40 fg of genome DNA of L. mirabilis KCOM 3484. These results indicate that this qPCR primer pair (RTLam-F4/RTLam-R3) may be useful for species-specific detection of L. mirabilis in epidemiological studies of oral bacterial infectious diseases such as periodontal disease.

• 정보화사회
• /
• s.94
• /
• pp.40-46
• /
• 1995

CALS의 개념을 한마디로 정의하기에는 범위나 방법상 어려움이 있다. 그럼에도 불구하고 과거에는 군의 무기체계를 지원하는 개념에서 출발하였으므로 일반적으로 "무기체계의 설계, 제작 및 군수유통체계 지원을 위해 디지털기술의 통합과 정보공유를 통한 신속한 자료처리 환경 구축"으로 정의할 수 있었다. 그러나 이제는 "제품의 생산(생산계획 등 이전 활동 포함)으로 부터 폐기에 이르는 모든 활동을 디지털정보기술의 통합을 통해 구현하는 산업화전략"이라는 표현으로 바꾸어야 할 것이며, 이것은 곧 제품에 대한 요람에서 무덤까지의 총체적 관리를 위한 정보기술 통합전략이라고 정의할 수 있을 것이다.

• Electrical & Electronic Materials
• /
• v.17 no.4
• /
• pp.40-46
• /
• 2004

나노테크놀러지(Nanotechnology)는 1965년도 노벨물리학상 수상자인 Richard P. Feynman이 1959년에 칼텍(CalTech)에서 했던 강연 "There's Plenty of Room at the bottom"에서 처음으로 예언되었다 그는 전 세계의 모든 정보를 2백분의 1인치 크기의 정육면체에 기록할 수 있는 날이 올 것이라고 예언하였다. 최근 기술 선진국들은 미래지식산업시대를 겨냥한 고부가가치 제품개발에 집중하고 있으며, 제품크기의 극소화를 통해 성능 고도화와 가격경쟁력 향상은 물론 에너지와 자원의 경제적 활용을 추구하고 있다.(중략)하고 있다.(중략)