• Title/Summary/Keyword: Dual stage

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A Study on the Filtration of BNR Process Effluent (BNR공정 처리수의 여과에 관한 연구)

  • Kim, Seong-Young;Bum, Bong-Su;Cho, Kwang-Myeung
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.5
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    • pp.895-905
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    • 2000
  • This study was performed to investigate the removal efficiencies of pollutants at various filtration rates and the quality of the filtered water along the depth of filter media during treatment of a BNR process effluent by a dual-media gravitational rapid filtration. The results of the experiments at filtration rates of 200, 300 and 400 m/day using the effluent of a pilot scale 4-stage BNR plant showed that turbidity of the filtered water was below 2.6 NTU, satisfying the Korean standard for water for reuse. Even though the SS removal efficiency deteriorated as the filtration rate increased, the average SS concentration of the filtered water was 1.3 mg/L at all filtration rates. Simultaneous biological nitrification and denitrification was observed with nitrification efficiencies of 17.4, 18.8 and 14.3%, and denitrification efficiencies of 32.3, 27.7 and 21.4% respectively at filtration rates of 200, 300 and 400 m/day. At the latter period of each filtration cycle, the effluent T-P concentration was higher than influent T-P concentration by 6.1 to 21.4% due to phosphorous release under DO-deficient condition.

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Nondestructive Evaluation and Microfailure Mechanisms of Single Fibers/Brittle Cement Matrix Composites using Electro-Micromechanical Technique and Acoustic Emission (Electro-Micromechanical 시험법과 Acoustic Emission을 이용한 단섬유/시멘트 복합재료의 미세파괴 메커니즘과 비파괴적 평가)

  • 박종만;이상일;김진원;윤동진
    • Composites Research
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    • v.14 no.3
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    • pp.18-31
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    • 2001
  • Interfacial and microfailure properties of the modified steel, carbon and glass fibers/cement composites were investigated using electro-pullout test under tensile and compressive tests with acoustic emission (AE). The hand-sanded steel composite exhibited higher interfacial shear strength (IFSS) than the untreated and even neoalkoxy zirconate (Zr) treated steel fiber composites. This might be due to the enhanced mechanical interlocking, compared to possible hydrogen or covalent bonds. During curing process, the contact resistivity decreased rapidly at the initial stage and then showed a level-off. Comparing to the untreated case, the contact resistivity of either Zr-treated or hand-sanded steel fiber composites increased to the infinity at latter stage. The number of AE signals of hand-sanded steel fiber composite was much more than those of the untreated and Zr-treated cases due to many interlayer failure signals. AE waveforms for pullout and frictional signals of the hand-sanded composite are larger than those of the untreated case. For dual matrix composite (DMC), AE energy and waveform under compressive loading were much higher and larger than those under tensile loading, due to brittle but well-enduring ceramic nature against compressive stress. Vertical multicrack exhibits fur glass fiber composite under tensile test, whereas buckling failure appeared under compressive loading. Electro-micromechanical technique with AE can be used as an efficient nondestructive (NDT) method to evaluate the interfacial and microfailure mechanisms for conductive fibers/brittle and nontransparent cement composites.

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The Records and Archives Administrative Reform in China in 1930s (1930년대 중국 문서당안 행정개혁론의 이해)

  • Lee, Won-Kyu
    • The Korean Journal of Archival Studies
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    • no.10
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    • pp.276-322
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    • 2004
  • Historical interest in China in 1930s has been mostly focused on political characteristic of the National Government(國民政府) which was established by the KMT(中國國民黨) as a result of national unification. It is certain that China had a chance to construct a modern country by the establishment of the very unified revolutionary government. But, it was the time of expanding national crises that threatened the existence of the country such as the Manchurian Incident and the Chinese-Japanese War as well as the chaos of the domestic situation, too. So it has a good reason to examine the characteristic and pattern of the response of the political powers of those days. But, as shown in the recent studies, the manifestation method of political power by the revolutionary regime catches our attention through the understanding of internal operating system. Though this writing started from the fact that the Nationalist Government executed the administrative reform which aimed at "administrative efficiency" in the middle of 1930s, but it put stress on the seriousness of the problem and its solution rather than political background or results. "Committee on Administrative Efficiency(行政效率委員會)", the center of administrative reform movement which was established in 1934, examined the plan to execute the reform through legislation by the Executive Council(行政院) on the basis of the results of relevant studies. They claimed that the construction of a modern country should be performed by not political revolution anymore but by gradual improvement and daily reform, and that the operation of the government should become modern, scientific and efficient. There were many fields of administrative reform subjects, but especially, the field of records and archives adminstration(文書檔案行政) was studied intensively from the initial stage because that subject had already been discussed intensively. They recognized that records and archives were the basic tool of work performance and general activity but an inefficient field in spite of many input staff members, and most of all, archival reform bring about less conflicts than the fields of finance, organization and personnel. When it comes to the field of records adminstration, the key subjects that records should be written simply, the process of record treatment should be clear and the delay of that should be prevented were already presented in a records administrative meeting in 1922. That is, the unified law about record management was not established, so each government organization followed a conventional custom or performed independent improvement. It was through the other records administrative workshop of the Nationalist Government in 1933 when the new trend was appeared as the unified system improvement. They decided to unify the format of official records, to use marker and section, to unify the registration of receipt records and dispatch records and to strengthen the examination of records treatment. But, the method of records treatment was not unified yet, so the key point of records administrative reform was to establish a unified and standard record management system for preventing repetition by simplifying the treatment procedure and for intensive treatment by exclusive organizations. From the foundation of the Republic of China to 1930s, there was not big change in the field of archives administration, and archives management methods were prescribed differently even in the same section as well as same department. Therefore, the point at issue was to centralize scattered management systems that were performed in each section, to establish unified standard about filing and retention period allowance and to improve searching system through classification and proper number allowance. Especially, the problem was that each number system and classification system bring about different result due to dual operation of record registration and archives registration, and that strict management through mutual contrast, searching and application are impossible. Besides, various problems such as filing tools, arrangement method, preservation facilities & equipment, lending service and use method were raised also. In the process this study for the system improvement of records and archives management, they recognized that records and archives are the identical thing and reached to create a successive management method of records and archives called "Records and Archives Chain Management Method(文書檔案連鎖法)" as a potential alternative. Several principles that records and archives management should be performed unitedly in each organization by the general record recipient section and the general archives section under the principle of task centralization, a consistent classification system should be used by classification method decided in advance according to organizational constitution and work functions and an identical number system should be used in the process of record management stage and archive management stage by using a card-type register were established. Though, this "Records and Archives Chain Management Method" was developed to the stage of test application in several organizations, but it was not adopted as a regular system and discontinued. That was because the administrative reform of the Nationalist Government was discontinued by the outbreak of the Chinese-Japanese War. Even though the administrative reform in the middle of 1930s didn't produce practical results but merely an experimentation, it was verified that the reform against tradition and custom conducted by the Nationalist Government that aimed for the construction of a modern country was not only a field of politics, but on the other hand, the weak basis of the government operation became the obstacle to the realization of the political power of the revolutionary regime. Though the subject of records and archives administrative reform was postponed to the future, it should be understood that the consciousness of modern records and archives administration and overall studies began through this examination of administrative reform.

A Study on Views of Vital Capital in Film (영화 <기생충>에 나타난 생명자본의 관점에 관한 연구)

  • Kang, Byoung-Ho
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.3
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    • pp.75-88
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    • 2021
  • The film won the Golden Palm Award at the Cannes Film Festival, and received the Academy Award for a non-English-speaking film in February 2020, respectively. It has received a monumental evaluation in the world film history. Overall, this film is about class conflict, and critics evaluate the theme of the film as "badly twisted class gap" and "anger from class." The film expresses an intrinsic conflict embodied in culture as a "tragedy in which no bad person appears," rather than the dichotomous composition of the classical class struggle from Marxism. In other words, this can be seen as expressing the substrated class relationship of the modern society that Pierre Bourdieu had argued. This film has been focused as a controversial target under Korea society with excess of ideology. Politics used to adopt the keyword, 'parasite', for political disputes not only in culture contents world. Paradoxically socialism China did not allow to release film 'Parasite.' On the other hand, Lee O-Yong argues that the movie "Parasite" does not look at social phenomena through a dichotomous perspective, but is viewed through a "double perspective" and evaluates that it does not lose eyes looking at humans through tension. This view is based upon 'Vital Capitalism'. Lee. O-Yong looks at the movie "Parasite" from the perspective of "Vital Capitalism". The theory of Vital Capitalism does not seek to find the root of historical development in class struggle conflicts, but rather figuring out history and society pays attention onto the intrinsic characteristics of life, Topophilia, Neophilia, and Biophilia. Lee Eo-ryeong argues that the development of civilization theory evolved from the stage of Hobbes' Darwinism or predatism to the stage of host vs. parasite of Michel Serres, and onto the stage of Margulis's 'Win-Win (inter-dependence)'. In this paper, after overview of vital capital concept and preceeding research, re-interpretations were tried onto scenes based upon fields from habitus, culture capital. This exploration looks for a alternative for excess of ideology in Korea society.

A New Understanding on Environmental Problems in China - Dilemma between Economic Development and Environmental Protection - (중국 환경문제에 대한 재인식 -경제발전과 환경보호의 딜레마-)

  • Won, Dong-Wook
    • Journal of Environmental Policy
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    • v.5 no.1
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    • pp.45-70
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    • 2006
  • China has achieved great economic growth above 9% annual since it changed to more of a market economy system by its reform and open-door policy. At the same time, China has experienced severe ecological deterioration, such as air and water pollutions caused by its rapid urbanization and industrialization. China is now confronted with environmental pollution and ecological deterioration at a critical point, at which economic development in China is limited. Moreover, environmental problems in China have become a lit fuse for social fluctuation beyond pollution problems. The root and background of environmental problems in China, firstly, are its government's lack of understanding of these problems and incorrect economic policies affected by political and ideological prejudice. Secondly, the plundering of resources, 'the principle of development first' which didn't consider environmental sustainability is another source of environmental deterioration in China. In addition, a huge population and poverty in China have increased the difficulty in solving its environmental problems, and in fact have accelerated them. The Chinese government has established many environmental laws and institutions, increased environmental investments, and is enlarging the participation of NGOs and the general public in some limited scale to solve its environmental problems. However, it has not obtained effective results because of the lack of environmental investments owing to the government's limit of the development phase, a structural limit of law enforcement and local protectionism, and the limit of political independency in NGOs and the lack of public participation in China. It seems that China remains in the stage of 'economic development first, environmental protection second', contrary to its catch-phrase of 'the harmony between economic development and environmental protection'. China is now confronted with dual pressure both domestically and abroad because of deepening environmental problems. There are growing public's protests and demonstrations in China in response to the spread of damage owing to environmental pollution and ecological deterioration. On the other hand, international society, in particular neighboring countries, regard China as a principal cause of ecological disaster. In the face of this dual pressure, China is presently contemplating a 'recycling economy' that helps sustainable development through the structural reform of industries using too much energy and through more severe law enforcement than now. Therefore, it is desirable to promote regional cooperation more progressively and practically in the direction of building China's ability to solve environmental problems.

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Dual-mode Pseudorandom Number Generator Extension for Embedded System (임베디드 시스템에 적합한 듀얼 모드 의사 난수 생성 확장 모듈의 설계)

  • Lee, Suk-Han;Hur, Won;Lee, Yong-Surk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.8
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    • pp.95-101
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    • 2009
  • Random numbers are used in many sorts of applications. Some applications, like simple software simulation tests, communication protocol verifications, cryptography verification and so forth, need various levels of randomness with various process speeds. In this paper, we propose a fast pseudorandom generator module for embedded systems. The generator module is implemented in hardware which can run in two modes, one of which can generate random numbers with higher randomness but which requires six cycles, the other providing its result within one cycle but with less randomness. An ASIP (Application Specific Instruction set Processor) was designed to implement the proposed pseudorandom generator instruction sets. We designed a processor based on the MIPS architecture,, by using LISA, and have run statistical tests passing the sequence of the Diehard test suite. The HDL models of the processor were generated using CoWare's Processor Designer and synthesized into the Dong-bu 0.18um CMOS cell library using the Synopsys Design Compiler. With the proposed pseudorandom generator module, random number generation performance was 239% faster than software model, but the area increased only 2.0% of the proposed ASIP.

Research Trends of an E-D Nozzle for Altitude Compensation (고도 보정용 확장-굴절(E-D) 노즐의 국외 연구 동향)

  • Moon, Taeseok;Park, Sanghyeon;Choi, Junsub;Huh, Hwanil
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.10
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    • pp.844-854
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    • 2017
  • The Expansion-Deflection(E-D) nozzle is a nozzle that has a performance gain through the altitude compensation effect by changing the effective area within the nozzle according to the altitude. An E-D nozzle has been known to reduce the length of the nozzle and achieve the payload gain of the launch vehicle. Due to the potential advantages of an E-D nozzle, related research has been carried out in the United Kingdom, Germany, Australia and Europe etc. In the UK, the flow characteristics of the E-D nozzle and the performance comparison with the dual-bell nozzle which is altitude compensation nozzle were studied. In order to understand the transition characteristics of the E-D nozzle in DLR, the transition characteristics according to the nozzle pressure ratio change were analyzed. In Europe, numerical study using the E-D nozzle concept on upper stage of the launch vehicle Ariane 5 ESC-B was carried out to confirm the possibility of payload gain according to the nozzle length reduction. In this paper, research trends of an E-D nozzle performed outside the country are classified and analyzed according to their characteristics and utilized as basic data of E-D nozzle research in the future.

The Effect of Red Cabbage (Brassica oleracea L. var. capitata f. rubra) Extract on the Apoptosis in Human Breast Cancer MDA-MB-231 Cells (적양배추 추출물이 인체 유방암 세포 MDA-MB-231의 세포사멸에 미치는 영향)

  • Nam, Mi Kyung;Kang, Keum Jee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.1
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    • pp.8-16
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    • 2013
  • We investigated the effect of red cabbage extract (RCE) on cell death in MDA-MB-231 human breast cancer cells. Cells were cultured in the presence 1.0, 1.5, and 2.0 mg/mL concentrations of RCE for 24 hours. MTT assays demonstrated that mitochondrial dehydrogenase activities decreased in a dose-dependent manner in cells (p<0.05). In contrast, the proportion of dual staining with Hoechst 33342/ethidium bromide (EtBr) for cell death increased in a dose-dependent manner in cells (p<0.05). Flow cytometry assays revealed that cell death caused by an apoptotic program increased in a dose-dependent (p<0.05). Also, increased ROS accumulation in cells, as revealed by DCF-DA staining, was observed in a dose-dependent fashion (p<0.05). The apoptosis suppressor gene Bcl-2 decreased significantly at the mRNA level. Pro-apoptotic genes Bax and caspase-3, genes that are related to the last stage of apoptosis significantly increased. The Bcl-2/Bax ratio which is an important indicator of apoptosis, was found to have significantly decreased dose dependence. These results taken together indicate that the effect of red cabbage extract induces cell death in MDA-MB-231 human breast cancer cells.

A Study of the RCS Reduction by Pattern Synthesis for Singly Curved Structures (패턴 합성을 통한 단일 곡면 구조에서의 RCS 감소 기술에 관한 연구)

  • Kim, Woojoong;Seo, Hyeong Pil;Kim, Youngsub;Yoon, Young Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.4
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    • pp.366-373
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    • 2013
  • This paper discusses the singly curved phased reflector for reduced RCS pattern, which has minimized RCS level at boresight with a null by phase cancelation and the lowered RCS level of main beam by splitting the main beam into multi directions. Considering the reduced level of boresight and main beam compared to the same sized reference PEC, this proposed multi-beam reflector can be adopted in the mono-static radar and the bi-static radar environment. The proposed reflector is a multi-beam reflector, which has different phase distributions at each row for different steering angle. It is designed through an intermediate stage of a single and dual-beam reflector. The behaviors of the designed reflectors are verified through full-wave simulation and experiment. The reflectors are designed in the frequency of 10 GHz and it has a size $240{\times}180mm^2$($8{\times}6\;{\lambda}^2$) with the curvature k=3.3. From the measured results, the proposed reflectors reduce the reflected power by 17 dB at boresight.

Novel DOX-MTX Nanoparticles Improve Oral SCC Clinical Outcome by Down Regulation of Lymph Dissemination Factor VEGF-C Expression in vivo: Oral and IV Modalities

  • Abbasi, Mehran Mesgari;Monfaredan, Amir;Hamishehkar, Hamed;Seidi, Khaled;Jahanban-Esfahlan, Rana
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6227-6232
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    • 2014
  • Background: Oral squamous cell carcinoma (OSCC) remains as one of the most difficult malignancies to control because of its high propensity for local invasion and cervical lymph node dissemination. The aim of present study was to evaluate the efficacy of novel pH and temperature sensitive doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NP) in terms of their potential to change the VEGF-C expression profile in a rat OSCC model. Materials and Methods: 120 male rats were divided into 8 groups of 15 animals administrated with 4-nitroquinoline-1-oxide to induce OSCCs. Newly formulated doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NP) and free doxorubicin were IV and orally administered. Results: Results indicated that both oral and IV forms of DOX-MTX-nanoparticle complexes caused significant decrease in the mRNA level of VEGF-C compared to untreated cancerous rats (p<0.05). Surprisingly, the VEGF-C mRNA was not affected by free DOX in both IV and oral modalities (p>0.05). Furthermore, in DOX-MTX NP treated group, less tumors characterized with advanced stage and VEGF-C mRNA level paralleled with improved clinical outcome (p<0.05). In addition, compared to untreated healthy rats, the VEGF-C expression was not affected in healthy groups that were treated with IV and oral dosages of nanodrug (p>0.05). Conclusions: VEGF-C is one of the main prognosticators for lymph node metastasis in OSCC. Down-regulation of this lymph-angiogenesis promoting factor is a new feature acquired in group treated with dual action DOX-MTX-NPs. Beside the synergic apoptotic properties of concomitant use of DOX and MTX on OSCC, DOX-MTX NPs possessed anti-angiogenesis properties which was related to the improved clinical outcome in treated rats. Taking together, we conclude that our multifunctional doxorubicin-methotrexate complex exerts specific potent apoptotic and anti-angiogenesis properties that could ameliorate the clinical outcome presumably via down-regulating dissemination factor-VEGF-C expression in a rat OSCC model.