• Journal of Microbiology and Biotechnology
• /
• 제24권10호
• /
• pp.1368-1376
• /
• 2014

This article focuses on the effects of glycine betaine on preventing caramelization, and increasing DCW and $\small{L}$-lysine production. The additional glycine betaine not only decreased the browning intensity (decreased 4 times), and the concentrations of 5-hydroxymethylfurfural (decreased 7.8 times) and furfural (decreased 12 times), but also increased the availability of glucose (increased 17.5%) for $\small{L}$-lysine production. The DCW and $\small{L}$-lysine production were increased by adding no more than 20 mM glycine betaine, whereas the DCW and $\small{L}$-lysine production were decreased with the reduction of pH values, although pH had a better response to prevent caramelization than did glycine betaine. For $\small{L}$-lysine production, the highest increase (40%) was observed on the media with 20 mM glycine betaine. The crucial enzymes in glycolysis and $\small{L}$-lysine biosynthesis pathway were investigated. The results indicated that additional glycine betaine increases the activity of enzymes in glycolysis, in contrast to the effect of pH. All the results indicated that glycine betaine can be used to prevent caramelization and increase the $\small{L}$-lysine production. By applying this strategy, glucose would not be have to be separated from the culture media during autoclaving so that factories can save production costs and shorten the fermentation period.

• 과학교육연구지
• /
• 제35권2호
• /
• pp.119-126
• /
• 2011

이 연구의 목적은 고등학교 화학 I 교과에서 small-scale chemistry (SSC)를 활용한 실험수업이 고등학생들의 학업성취도와 과학적 태도 및 과학에 관련된 태도에 미치는 영향을 알아보는 것이다. 연구를 위하여 고등학교 2학년 2개 학급을 실험집단과 통제집단으로 나누어 실험집단에는 SSC를 활용한 실험수업을, 통제집단에는 교과서에 제시된 전통적인 실험수업을 실시하였다. 연구 결과, SSC를 활용한 실험수업은 전통적인 실험수업에 비해 학업성취도를 향상시키는 효과가 있었으며, 과학적 태도에서는 자진성과 끈기성 및 협동성을, 과학에 관련된 태도에서는 과학의 사회적 의미와 과학교과에 대한 태도 및 과학에 대한 태도를 향상시키는 효과가 있었다. 그러므로 교육 현장에서는 SSC를 활용한 실험수업을 고등학교 화학교과에 적극적으로 활용할 필요가 있다.

• 대한의용생체공학회:의공학회지
• /
• 제27권6호
• /
• pp.376-383
• /
• 2006

Noise induced hearing loss (NIHS), the well-known occupational disease, is caused by continuous excessive noise. The prevention of NIHS is very important, because it is unrecoverable. There are some kinds of hearing protection device (HPD), and those are effective in preventing NIHS. But workers in noisy environment often resist to wearing them. Because they are ready - made products, so workers feel uncomfortable to wear. Also, they didn't maintain the conversation frequency range, so workers are hard to communicate in wearing them. To prevent hearing loss effectively, it is important that workers keep wearing HPD. Therefore, a HPD is needed to be comfortable to wear and be effective not only in hearing protection but also in preserving communication ability. So we proposed a custom - made hearing protection device in which a small acoustic filter is inserted. We designed several kinds of small acoustic filters and carried out some acoustic experiments for measuring characteristics of filters. We confirmed that acoustic transmission characteristic can be adjusted from experimental results using designed small acoustic filters. And we researched for the actual efficiency of a new developed custom - made hearing protection device using a small size acoustic filter. Also, we found out that workers are more satisfied with the new development than a former protection device from a workers' response.

• 대한의용생체공학회:의공학회지
• /
• 제25권2호
• /
• pp.97-102
• /
• 2004

소 동물 촬영에 이용될 수 있는 고해상도의 x-선 cone-beam micro computed tomography (micro-CT) 시스템을 개발하였다 Micro-CT 시스템은 120${\times}$120 mm2 의 2차원 평판 x-선 감지기, micro-focus x-선 발생장치, 주사 기구부, 병렬처리 영상 재구성 시스템으로 이루어져 있다. 개발된 시스템의 성능을 평가하기 위해 대조도와 공간해상도를 측정하였다. 대조도 실험에서는 95 mGy 에서 36 CT-번호를 구별할 수 있음을 확인하였고, 공간 해상도 실험에서는 14 lp/mm 의 성능을 확인하였다. 소 동물 촬영 결과로 실험용 쥐의 대퇴부, 심장 그리고 복부 동맥 혈관을 촬영한 경상을 제시하였다. 개발된 micro-CT 시스템은 소 동물을 이용한 생명공학 분야 연구에 널리 이용될 수 있을 것으로 기대된다.

• Radiation Oncology Journal
• /
• 제36권3호
• /
• pp.227-234
• /
• 2018

Purpose: We compared how doses delivered via two-dimensional (2D) intracavitary brachytherapy (ICBT) and three-dimensional (3D) ICBT varied anatomically. Materials and Methods: A total of 50 patients who received 30 Gy of 3D ICBT after external radiotherapy (RT) were enrolled. We compared the doses of the actual 3D and 2D ICBT plans among patients grouped according to six anatomical variations: differences in a small-bowel V_2Gy, small bowel circumference, the direction of bladder distension, bladder volume, sigmoid V_3.5Gy, and sigmoid circumference. Seven dose parameters were measured in line with the EMBRACE recommendations. Results: In terms of bladder volume, the bladder and small-bowel D_2cc values were lower in the 150-250 mL bladder volume subgroup; and the rectum, sigmoid, and bladder D_2mL values were all lower in the >250 mL subgroup, for 3D vs. 2D ICBT. In the sigmoid V_3.5Gy >2 _mL subgroup, the sigmoid and bladder D_2mL values were significantly lower for 3D than 2D ICBT. The bladder D_2mL value was also significantly lower for 3D ICBT, as reflected by the sigmoid circumference. In patients with a small bowel V_2.0Gy >10 mL or small bowel circumference >15%, most dose parameters were significantly lower for 3D than 2D ICBT. The bladder distension direction did not significantly affect the doses. Conclusion: Compared to 2D ICBT, a greater bladder volume can reduce the internal 3D ICBT organ dose without affecting the target dose.

• Kyungpook Mathematical Journal
• /
• 제50권3호
• /
• pp.447-454
• /
• 2010

In this paper, we investigate the uniqueness problems of meromorphic functions that share a small function with its differential polynomials, and give a result which is related to a conjecture of R. Br$\"{u}$ck and improve the results of I. Lahiri and Q. C. Zhang.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
• /
• pp.642-647
• /
• 1998

A new small-signal model for the controlled on-time boost power factor correction (PFC) circuit is presented. The proposed small-signal model is valid up to high frequencies over lKHz. The model can be used in designing the voltage feedback compensation of PFC circuits, the control bandwidth of which is maximized with auxiliary means of removing the low-frequency ripple from the output. The accuracy of the model is confirmed by a 200W experimental hardware

• 교육녹색환경연구
• /
• 제22권4호
• /
• pp.1-8
• /
• 2023

학령인구의 급격한 감소에 따른 학교의 소규모화가 가속화되고 있으며, 지역 및 학교 소멸에 대한 위기가 고조되고 있는 상황에서 소규모학교에서 미래교육 대응에 대한 필요성이 점점 증가하고 있다. 미래에는 유연한 교육과정, 디지털·인공지능 기반의 교실 수업 개선 등과 같은 교육과정을 통해서 학생들의 학교생활 만족도 향상, 창의성 및 인성 함양, 학업성취도 향상, 협력적 소통 역량 강화와 교사들의 교수학습 방법의 변화 등의 교육적 효과가 중요하다고 볼 수 있으며, 이를 위해서는 학교공간혁신 등 학교시설을 미래지향적인 공간으로 변화시킬 필요가 있다. 본 연구는 소규모 학교에서 미래형 교육체제가 무엇인지를 살펴보았고 학교공간 변화와 학교교육 상관관계, 스마트 환경 등 공간혁신의 교육적 효과와 지속가능성에 대한 인식을 중점적으로 분석하여 향후 소규모학교 공간혁신사업의 바람직한 추진 방향을 제시하였다.

• 한국정보기술응용학회:학술대회논문집
• /
• 한국정보기술응용학회 2002년도 춘계학술대회
• /
• pp.7-9
• /
• 2002

• 한국임상수의학회:학술대회논문집
• /
• 한국임상수의학회 2007년도 춘계학술대회
• /
• pp.146-146
• /
• 2007