• 제목/요약/키워드: Water improvement

검색결과 4,085건 처리시간 0.033초

A Revisit to the Recent Human Error Events in Nuclear Power Plants Focused to the Organizational and Safety Culture

  • Lee, Yong-Hee
    • 대한인간공학회지
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    • 제32권1호
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    • pp.117-124
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    • 2013
  • Objective: This paper presents additional considerations related to organization and safety culture extracted from recent human error incidents in Korea, such as station blackout(i.e., SBO) in Kori#1. Background: Safety culture has been already highlighted as a major cause of human errors after 1986 Chernobyl accident. After Fukushima accident in Japan, the public acceptance for nuclear energy has taken its toll. Organizational characteristics and culture became elucidated as a major contributor again. Therefore many nuclear countries are re-evaluating their safety culture, and discussing any preparedness and its improvement. On top of that, there was an SBO in 2012 in the Kori#1. Korean public feels frustrated due to the similar human errors causing to a catastrophe like Fukushima accident. Method: This paper reassesses Japan's incidents, and revisits Korea's recent incidents. It focuses on the analysis of the hazards rather than the causes of human errors, the derivation of countermeasures, and their implementation. The preceding incidents and conclusions from Japanese experience are also re-analyzed. The Fukushima accident was an SBO due to the natural disaster such as earthquakes and a successive tsunami. Unlike the Fukushima accident, the Kori#1 incident itself was simple and restored without any loss and radioactive release. However, the fact that the incident was deliberately concealed led to massive distrust. Moreover, the continued violation of rules and organized concealment of the accident are serious signs of a new distorted type of human errors, blatantly revealing the cultural and fundamental weakness of the current organization. Result: We should learn from Japanese experiences who had taken pride in its safety technology and fairly high confidence in safety culture. Japan's first criticality accident in JCO facility splashed cold water on that confidence. It has turned out to be a typical case revealing the problems in the organization and safety culture. Since Japan has failed to gain lessons and countermeasure, the issue persists to the Fukushima incident. Conclusion: Safety culture is not a specific independent element, which makes it difficult to either evaluate it properly or establish countermeasures from the lessons. It may continue to expose similar human errors such as concealment of incident and manipulation of bad data. Application: Not only will this work establish the course of research for organization and safety culture, but this work will also contribute to the revitalization of Korea's nuclear industry from the disappointment after the export contract to UAE.

COMPARATIVE STUDY ON THE FRACTURE STRENGTH OF EMPRESS 2 CERAMIC AND TARGIS-VECTRIS CROWN

  • Cha Young-Joo;Yang Jae-Ho;Lee Sun-Hyung;Han Jung-Suk
    • 대한치과보철학회지
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    • 제39권6호
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    • pp.599-610
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    • 2001
  • Due to an increasing interest in esthetics and concerns about toxic and allergic reactions to certain alloys, patients and dentists have been looking for metal-free tooth-colored restorations. Recent improvement in technology of new all-ceramic materials and composite materials has broadened the options for esthetic single crown restorations. The aim of this investigation was to study the fracture strength of the metal-free posterior single crowns fabricated using two recently introduced systems, Empress 2 ceramic and Targis-Vectris. Forty premolar-shaped stainless steel dies with the 1mm-wide circumferential shoulder were prepared. Ten cylindrical crowns having a diameter of 8.0mm and total height of 7.5mm were fabricated for each crown system respectively(PFM, Empress staining technique, Empress 2 layering technique, and Targis- Vectris). The crowns were filled with cement and placed on the stainless steel dies with firm finger pressure. The crowns were then stored in distilled water at room temperature for 24 hours before testing. The crowns were tested for fracture strength in an Instron universal testing machine (Instron 6022). With a crosshead speed of 1mm/min the center of the occlusal surface of the crown was loaded using a 4-mm-diameter stainless steel ball until fracture occurred. The fracture surfaces of the crowns were gold coated and examined using scanning electron microscopy(Jeol JSM-840 Joel Ltd., Akishima, Tokyo, Japan). Within the parameters of this study the following conclusions were drawn: 1. The mean fracture strength for PFM crowns was 5829(${\pm}906$)N; for Empress staining technique the fracture strength was 1697(${\pm}604$)N; for Empress 2 Layering technique the fracture strength was 1781N(${\pm}400$)N, and the fracture strength for Targis- Vectris was 3093(${\pm}475$)N. 2. The fracture strength of the PFM crowns was significantly higher than that of the Empress 2 and the Targis-Vectris crowns (P<0.05). 3. The fracture strength of the Targis-Vectris crowns was significantly higher than that of the Empress 2 crowns (P<0.05). 4. No statistical difference was found when Empress staining technique was compared with Empress 2 layering technique. 5. The SEM image of fracture surface of Empress 2 crown showed a very dense microstructure of the lithium disilicate crystals and the SEM image of fracture surface of Targis-Vectris crown showed indentations of Vectris and some fibers tom off from Vectris.

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작두콩 첨가 청국장의 Isoflavonoids 함량과 항균력 및 생리활성 (Isoflavonoid Contents, Antibacterial Activities, and Physiological Activities of Cheonggukjang Made from Sword Bean)

  • 김운성;김재영;김성조;문광현;백승화
    • 한국식품영양과학회지
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    • 제41권2호
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    • pp.174-181
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    • 2012
  • 본 연구는 영양과 기능성을 보유한 작두콩으로 제조한 청국장의 isoflavonoids 함량과 항균성 및 생리활성을 조사한 결과로서 청국장 제조과정에서 사용하는 원료, 증자한 원료 및 이를 발효시킨 청국장을 비교 분석하였다. 작두콩으로 제조한 청국장(Cheonggukjang made from the sword bean: CS)의 gram positive bacteria에 대한 항균력은 전통청국장(traditional Cheonggukjang: TC)과 비교하여 에탄올 추출에서는 Bacillus cereus, 물 추출은 Staphylococcus aureus에서 높은 결과를 나타내었다. 그러나 CS의 gram negative bacteria에 대한 항균력은 모든 추출물이 Salmonella Typhimurium에서 가장 높은 결과를 나타내었다. 항산화활성과 총 플라보노이드 함량은 청국장으로 발효함에 따라 증가하는 경향이었고 기존의 TC보다 SC가 우수하였다. CS의 isoflavonoids 함량에서 glycoside 형태인 daidzin과 genistin은 증자 과정에서는 감소되었으나 청국장으로 발효시키면 증가되어 가장 높았다. 한편 aglycone 형태인 daidzein, glycitein, genistein의 경우도 증자 과정에서 감소경향을 보이나 발효되면서 증가하였다. ACE 저해활성은 원료<증자 원료<발효 청국장 순으로 증가하였고, 각각의 추출조건에서 CS의 추출물이 가장 우수하였다. 이상의 결과를 종합하면 청국장 제조 시 작두콩 첨가는 항균성, 항산화능, 총 flavonoid, isoflavonoids, ACE 저해활성 등의 기능성을 강화할 수 있는 원료로 확인되었다.

종이 의상에 관한 연구 - 수제지를 중심으로 - (A Study on the Paper Clothing -on the basis of handmade paper-)

  • 이주실;김정혜
    • 복식
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    • 제44권
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    • pp.181-199
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    • 1999
  • The industry of modern clothing has deviated from the overflow of commercialism and the standardization and nowadays is going toward pursuing art, creativity, and high added value. This trend brings the return of the natural materials from the synthetic textiles and increases the value of old and handmade fabrics. Finally, the handmade-paper, which is a natural material, comes to be reconsidered as a new material for the clothing. Therefore, as the natural materials and the manufacture of handmade clothing are rising again, the qualitative improvement and globalization of clothing industry should be first realized through the developments of creative and various clothing materials and new expressing techniques. The above investigation and study have been synthesized and analyzed as follows: First, through the study on the origin of the paper clothing, its historical background and the process of its development, we've learned these two facts following : the paper clothing of the East in the past mostly had practiced meanings. On the other hand, in the West it had meanings which were raised the artist's emotions and beauty-consciousness to the artistic level by the various kinds of expressing methods. Second, handmade-paper was manufactured by the embedding method, which mixed mulberry pulp, gauze, corn, hair, sisal, silk and so on. It was found that handmade-paper had the affluent and proper texture as the clothing material and was be able to control the clarity through the variation of thickness. It was also confirmed that the creative and original texture with hand-worked molding beauty was obtained by the use of handmade-paper. Third, when the handmade-paper is used, the molding beauty of plane, relievo, and solid can be freely pursued, and various and effective molding conformation can be constructed by the effect of superposition and repetition. Also, because the maximum discretion from the various optional manufacturing methods is allowed, the molding beauty can be maximized when the clothes are manufactured with handmade-paper. Fourth, the gauze with strong drape was combined to overcome the stiffness and the tearing of the paper. As a result, the durability and the wearability of the paper were strengthened and thus the thus the applications as the clothing material were enlarged. In conclusion, in order to enhance the value, creativity, practicality, and artistic sense of the design for modern clothing, the clothes made of handmade-paper should be more studied. Moreover, for the generalization of paper clothes, the studies on the development of practical paper with paper with water resistance, post-treatment after dyeing, flexibility, and durability should be done. I really hope that this study will be the motive to provoke the possibility of handmade-paper as new clothing material in not only practical sense but also artistic sense.

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Practical Virtual Compensator Design with Dynamic Multi-Leaf Collimator(dMLC) from Iso-Dose Distribution

  • Song, Ju-Young;Suh, Tae-Suk;Lee, Hyung-Koo;Choe, Bo-Young;Ahn, Seung-Do;Park, Eun-Kyung;Kim, Jong-Hoon;Lee, Sang-Wook;Yi, Byong-Yong
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.129-132
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    • 2002
  • The practical virtual compensator, which uses a dynamic multi-leaf collimator (dMLC) and three-dimensional radiation therapy planning (3D RTP) system, was designed. And the feasibility study of the virtual compensator was done to verify that the virtual compensator acts a role as the replacement of the physical compensator. Design procedure consists of three steps. The first step is to generate the isodose distributions from the 3D RTP system (Render Plan, Elekta). Then isodose line pattern was used as the compensator pattern. Pre-determined compensating ratio was applied to generate the fluence map for the compensator design. The second step is to generate the leaf sequence file with Ma's algorithm in the respect of optimum MU-efficiency. All the procedure was done with home-made software. The last step is the QA procedure which performs the comparison of the dose distributions which are produced from the irradiation with the virtual compensator and from the calculation by 3D RTP. In this study, a phantom was fabricated for the verification of properness of the designed compensator. It is consisted of the styrofoam part which mimics irregular shaped contour or the missing tissues and the mini water phantom. Inhomogeneous dose distribution due to the styrofoam missing tissue could be calculated with the RTP system. The film dosimetry in the phantom with and without the compensator showed significant improvement of the dose distributions. The virtual compensator designed in this study was proved to be a replacement of the physical compensator in the practical point of view.

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Improvement of Fat Suppression and Artifact Reduction Using IDEAL Technique in Head and Neck MRI at 3T

  • Hong, Jin Ho;Lee, Ha Young;Kang, Young Hye;Lim, Myung Kwan;Kim, Yeo Ju;Cho, Soon Gu;Kim, Mi Young
    • Investigative Magnetic Resonance Imaging
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    • 제20권1호
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    • pp.44-52
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    • 2016
  • Purpose: To quantitatively and qualitatively compare fat-suppressed MRI quality using iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) with that using frequency selective fat-suppression (FSFS) T2- and postcontrast T1-weighted fast spin-echo images of the head and neck at 3T. Materials and Methods: The study was approved by our Institutional Review Board. Prospective MR image analysis was performed in 36 individuals at a single-center. Axial fat suppressed T2- and postcontrast T1-weighted images with IDEAL and FSFS were compared. Visual assessment was performed by two independent readers with respect to; 1) metallic artifacts around oral cavity, 2) susceptibility artifacts around upper airway, paranasal sinus, and head-neck junction, 3) homogeneity of fat suppression, 4) image sharpness, 5) tissue contrast of pathologies and lymph nodes. The signal-to-noise ratios (SNR) for each image sequence were assessed. Results: Both IDEAL fat suppressed T2- and T1-weighted images significantly reduced artifacts around airway, paranasal sinus, and head-neck junction, and significantly improved homogeneous fat suppression in compared to those using FSFS (P < 0.05 for all). IDEAL significantly decreased artifacts around oral cavity on T2-weighted images (P < 0.05, respectively) and improved sharpness, lesion-to-tissue, and lymph node-to-tissue contrast on T1-weighted images (P < 0.05 for all). The mean SNRs were significantly improved on both T1- and T2-weighted IDEAL images (P < 0.05 for all). Conclusion: IDEAL technique improves image quality in the head and neck by reducing artifacts with homogeneous fat suppression, while maintaining a high SNR.

벌꿀을 이용한 고액분리 숙성 탁주의 주질 향상과 고형분의 조절에 따른 품질유지기간 증대 (Improvement of Takju Quality by a Ripening-Fermentation Process Using Honey and Extension of Shelf Life by Control of Takju Mash Sediment)

  • 정승진;신태선;김진만
    • 생명과학회지
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    • 제22권1호
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    • pp.80-86
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    • 2012
  • 우리 나라 전통술인 탁주의 주질 개선을 위한 목적으로 천연성과 기능성을 가진 벌꿀을 사용하였고 저장기간의 연장을 위하여 술액의 침전물 양을 조절할 목적으로 본 연구를 진행하였다. 발효방식은 주모발효 후 3단담금 방식으로 하였고, 입국균은 Aspergillus awamori var. kawachi, 원료는 100% 백미, 알코올 발효 효모는 Saccharomyces cerevisiae를 사용하였다. 제성액의 고형분과 술액을 분리하여 벌꿀을 최종농도 5%(w/v) 첨가하여 5, 10, $15^{\circ}C$에서 23일간 숙성하였을 때 온도에 따른 유의한 차이는 보이지 않았으며 숙성기간 동안 알코올이 미소하게 감소했을 뿐 pH, 산도 및 총당량은 거의 일정하였다. 이와 같이 특징적인 술액의 차이는 없었지만 벌꿀숙성으로 제조한 탁주가 벌꿀 첨가 직후의 미숙성 탁주와 비교할 때 우수한 관능 테스트 결과를 보여주었다. 추가적으로 냉동 보관한 고형분을 100%, 50% 및 25% 비율로 벌꿀첨가 숙성된 술액과 혼합한 후 물을 보충하여 알코올 8%의 탁주를 제조하고 37일간 $10^{\circ}C$에서 날짜 별로 분석하였다. pH는 모든 탁주에서 4.5~4.8 사이를 큰 차이 없이 유지하였으며 고형분 첨가량이 많을수록 효모 세포수, 산도 및 알코올 함량은 상대적으로 증가하였고 총당량은 감소함을 보여 주었다. 즉 고형분의 양이 소량일수록 탁주의 주질이 안정하였다. 결론적으로 발효 후 고액 분리하여 상층액에 벌꿀을 첨가함으로써 저온 숙성기간 동안 주질의 큰 변화를 주지 않고 관능적으로 우수한 술액을 만들 수 있었으며, 고형분의 재혼합 비율을 조절할 경우 저장기간이 증대된 탁주를 제조할 수 있을 것이다.

고구마를 첨가한 저맥아 맥주의 양조와 품질 특성 (Brewing and Properties of Low-Malt Beer with a Sweet Potato Paste)

  • 양하나;오은비;박정섭;정문웅;최동성
    • 한국식품영양학회지
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    • 제30권3호
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    • pp.491-500
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    • 2017
  • 신율미와 신자미 페이스트, 맥아, 효소제, 홉을 사용하여 고구마-맥아 당화액을 제조하고, 하면 발효효모 및 상면 발효효모를 접종, 발효하여 라거 및 에일 고구마 맥주를 제조하였다. 고구마 당화시 ${\alpha}-amylase$ 계 효소제를 첨가했을 때 여과성 향상과 당도 증가 효과가 가장 좋았다. ${\alpha}-Amylase$ 계 효소제를 0.1% 첨가하여 three step infusion 법으로 고구마-맥아 당화액을 제조했을 때 맥주 양조를 위한 최적 당도인 $13.5^{\circ}Brix$를 갖는 당화액이 얻어졌다. 라거 및 에일 신자미 맥주에서 고구마 첨가량이 증가함에 따라 폴리페놀 및 안토시아닌 함량이 증가하였고, DPPH 및 ABTS 라디칼 소거효과도 크게 증가하였다. 신율미 맥주에서는 감소하는 경향을 나타내었다. 고구마 맥주의 항산화 활성과 폴리페놀 함량 사이에는 강한 상관관계가 있었다. 라거 및 에일 신자미 맥주 모두에서 고구마 41.6%를 첨가했을 때 관능평가가 양호하였고, 미려한 적색의 색조를 띄었다.

재구성 햄 제조 시 Transglutaminase 첨가에 의한 텀블링 시간의 단축과 전단력 증진 효과 (Reduction of Tumbling Time and Improvement of Shear Value for the Manufacture of Restructured Hams using Transglutaminase)

  • 이홍철;진구복
    • 한국축산식품학회지
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    • 제24권1호
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    • pp.23-28
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    • 2004
  • 본 연구는 TGase를 사용함으로써 재구성육 햄의 결착력과 텀블링시간에 미치는 영향을 조사하기 위하여 실시하였다. 재구성 햄은 73.9∼75.7% 수분, 3.63∼4.18% 지방, 16.6∼20.6% 단백질로 구성되었고, pH는 5.95∼6.10 그리고 0.95∼0.96의 수분 활성도를 보였다. 텀블링시간의 증가나 TGase 첨가에 의한 발색과 기능성에는 유의차를 보이지 않았으나 TGase 무첨가구는 첨가구에 비해 텀블링시간에 관계없이 조직학적 성상이 낮게 나타났다. 전단력은 재구성육 햄에서 TGase를 첨가하지 않은 경우 텀블링시간을 길게 하거나 또는 TGase의 첨가시 전단력이 향상되었다. 즉, TGase의 첨가는 1시간으로 텀블링시간을 줄인 대조구가 텀블링시간이 4시간인 대조구에 비해 조직학적 성상이나 전단력이 유의적 차이를 보여 저하된 것에 반하여, 유의차 없는 조직학적 성상과 전단력을 보여줌으로써 텀블링시간의 감소에 대한 보완적 효과를 나타내었고, 반면에 TGase를 첨가하고 4시간동안 텀블링하였던 처리구 TRT 4는 4시간 동안 텀블링만을 한 CTL 4와 조직학적 성상과 전단력의 향상을 보여주지 못하였다. 즉, TGase 첨가에 의한 효과와 텀블링 시간의 증가로 인한 효과는 각각 나타났으나, 두 요인의 복합에 의한 상승효과는 나타나지 않았다. 결론적으로 재구성육 햄의 제조에 있어서 0.3% TGase의 첨가는 전단력을 증가시킴으로써 상대적으로 텀블링 시간을 줄이는 효과를 나타냈고, 대조구(CTL 1)에 대해서는 조직감과 전단력의 보완적 효과를 보여준 것으로 사료되어진다.

정어리 냉동고기풀의 품질개선에 관한 연구 (Study on the Quality Improvement of Sardine Surimi)

  • 오광수;문수경;이응호;김복규
    • 한국식품과학회지
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    • 제25권4호
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    • pp.327-333
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    • 1993
  • 정어리 냉동고기풀의 최적 가공조건은 원료 정어리를 알칼리 염수수세한 후 정어리 육에 대해 분리 대두단백질 : 물 : 정제 정어리유(1:5:2.6)로 만든 유화커드를 20%, 솔비톨 4%, 설탕 4%, 중합인산염 0.2% 및 항산화제로서 에리소르빈산나트륨을 0.1% 첨가하여 고기갈이한 후 $-35^{\circ}C$에서 급속동결시켜 carbon box로 포장하여 동결저장한 제품이 가장 좋았다. 본 제품의 수분함량은 73.3%, 조단백질 15.0%, 조지방은 6.9%였으며, 생균수는 $1.6{\sim}1.8{\times}10^4/g$으로 동결저장 중 변화는 거의 없었다. 제품의 주요 구성지방산은 16:0, 16:1, 18:1, 20:5 및 22:6 등으로 고도 불포화지방산이 47.7% 함유되어 있었다. 동결저장 중 120일 동안 제품의 물성, 지질산화 및 지방산의 변화 등을 측정한 결과, 유화커드와 에리소르빈산나트륨을 첨가함으로서 동결저장 중 단백질 변성, 지질의 산화 및 변색을 효율적으로 억제시킬 수 있었으며, 품질이 안정하게 유지되었다. 한편, 본 시제품과 명태 냉동고기풀을 혼합하여 가공한 어묵의 품질을 측정한 결과, 어묵의 품질에 큰 저하됨이 없이 명태 고기풀을 본 정어리 고기풀로 40%까지 대체할 수 있었으며 어육의 풍미를 갖는 연제품을 가공할 수 있다는 결론을 얻었다.

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