A Study of the SPWM High-Frequency Harmonic Circulating Currents in Modular Inverters

Sheng Xu,Zhendong Ji 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Due to detection and control errors, some high-frequency harmonics with voltage-source characteristics cause circulating currents in modular inverters. Moreover, the circulating currents are usually affected by the output filters (OF) of each module due to their filter and resonance properties. The interaction among the circulating currents in the modules increase the power loss and reduce system stability and control precision. Therefore, this paper reports the results of a study on the SPWM high-frequency harmonics circulating currents for a double-module VSI. In the paper, an analysis of the circulating-current circuits is briefly described. Next, a mathematic model of the single-module output voltage based on the carrier frequency of SPWM is built. On this basis, through mathematic modeling of high-frequency harmonic circulating currents, the formation mechanism and distribution characteristics of circular currents and their influences are studied in detail. Finally, the influences of the OF on the circulating currents are studied by mainly taking an LC-type filter as an example. A theoretical analysis and experimental results demonstrate some important characteristics. First, the carrier phase shifting of the SPWM for each module is the major cause of the SPWM harmonic circulating currents, and the circulating currents are in an odd distribution around n-times the carrier frequency nωs, where n = 1, 2, 3, …. Second, the harmonic circular currents do not flow into the parallel system. Third, the OF can effectively suppress the non-circulating part of the high-frequency harmonic currents but is ineffective for the circulation part, and actually reduces system stability.

A Study of the SPWM High-Frequency Harmonic Circulating Currents in Modular Inverters

Xu, Sheng,Ji, Zhendong The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Due to detection and control errors, some high-frequency harmonics with voltage-source characteristics cause circulating currents in modular inverters. Moreover, the circulating currents are usually affected by the output filters (OF) of each module due to their filter and resonance properties. The interaction among the circulating currents in the modules increase the power loss and reduce system stability and control precision. Therefore, this paper reports the results of a study on the SPWM high-frequency harmonics circulating currents for a double-module VSI. In the paper, an analysis of the circulating-current circuits is briefly described. Next, a mathematic model of the single-module output voltage based on the carrier frequency of SPWM is built. On this basis, through mathematic modeling of high-frequency harmonic circulating currents, the formation mechanism and distribution characteristics of circular currents and their influences are studied in detail. Finally, the influences of the OF on the circulating currents are studied by mainly taking an LC-type filter as an example. A theoretical analysis and experimental results demonstrate some important characteristics. First, the carrier phase shifting of the SPWM for each module is the major cause of the SPWM harmonic circulating currents, and the circulating currents are in an odd distribution around n-times the carrier frequency $n{\omega}_s$, where n = 1, 2, 3, ${\ldots}$. Second, the harmonic circular currents do not flow into the parallel system. Third, the OF can effectively suppress the non-circulating part of the high-frequency harmonic currents but is ineffective for the circulation part, and actually reduces system stability.

폐기물, 재활용, 순환자원에 관한 법체계

김연태 ( Kim Yeon-tae ) 고려대학교 법학연구원 2021 고려법학 Vol.- No.101

현행 폐기물 관리 법체계는 「폐기물관리법」, 「자원의 절약과 재활용 촉진에 관한 법률」, 「자원순환기본법」, 그리고 그 밖에 다수의 개별 법령으로 구성되어 있다. 「자원순환기본법」의 제정으로 우리나라의 폐기물 정책은 ‘폐기물 관리’에서 ‘자원의 순환’으로 패러다임이 전환되었다고 볼 수 있다. 「폐기물관리법」및 「자원의 절약과 재활용촉진에 관한 법률」등에서 규정하고 있는 정책수단은 발생된 폐기물의 사후 관리에 중점을 두고 있기 때문에 이러한 법률들과 정책수단으로는 지속가능한 사회의 구현이 불가능하다고 보았다. 이에 제품 등의 생산부터 유통·소비·폐기에 이르기까지 보다 효율적으로 자원이 이용되도록 관리하고, 자원의 순환이용을 촉진함으로써 자원이 순환되는 사회의 기반을 구축하기 위하여 「자원순환기본법」이 제정되었다고 밝히고 있다. 자원순환사회의 형성을 목적으로 제정된 「자원순환기본법」이 시행된지 3년여가 지났으나, 이 법의 시행으로 기존의 문제가 해결되고 우리 사회가 자원순환사회로 전환되는 등의 실효성을 거두고 있다고 보기는 어렵다. 「자원순환기본법」은 선언적·원칙적 내용을 주로 담고 있으며 자원순환사회로 나아가야 할 방향을 제시하고 있을 뿐, 구체적인 실현방안에 있어서는 매우 미흡하다고 평가된다. 또한 폐기물 관련 법률들의 체계성과 연계성이 약하다는 비판을 받는다. 자원순환사회의 형성을 위하여서는 폐기물로 인한 건강과 환경에 대한 위해의 예방과 자원의 효율적 활용이라는 두 가지 목적을 적절하게 조화시킬 수 있도록 법체계를 정립할 필요가 있다. 무엇보다도 원천적으로 폐기물의 발생을 억제하고, 자원의 순환적인 이용을 촉진할 수 있는 실효적이며 집행력 있는 제도를 마련하는 데 더 많은 관심을 기울여야 할 것이다. 이 글에서는 「자원순환기본법」제정 이후 폐기물 관리에 관한 현행법체계, 특히 폐기물과 재활용, 순환자원의 관계에 대하여 고찰하고, 자원순환사회에서 순환경제의 목적을 달성하기 위한 중요한 수단이라 할 수 있는 폐기물법상의 생산자책임에 대하여 살펴본다. 그리고 폐기물 관리와 자원순환 관련 법체계의 정립을 위하여 현행 법체계의 문제점과 입법적 개선방향에 대하여 살펴보고자 한다. The current legal system regarding wastes control is composed of the Wastes Control Act, the Act on the Promotion of Saving and Recycling of Resources, the Framework Act on Resources Circulations, and other numerous individual statues. It can be argued that the enactment of the Framework Act on Resources Circulations signals a paradigm shift in South Korean wastes policy, from wastes control to resources circulation. As the policy measures prescribed in the Wastes Control Act or the Act on the Promotion of Saving and Recycling of Resources focus on the ex post facto management of wastes, the writers of the Framework Act believed that they do not suffice for the purpose of a truly sustainable society. The writers say that the Framework Act on Resources Circulations has been enacted to control resources more efficiently from manufacturing, to consumption and disposal of products, and to establish a foundation of a resource-circulating society by promoting circular utilization of resources. Even three years after the Framework Act on Resources Circulations has entered into force with the aim of formulating a resource-circulating society, there has not been enough practical evidence that demonstrates fulfillment of that aim. The Framework Act on Resources Circulations is criticized for its lack of a concrete implementation plan, as its content mainly focuses on declarations, principles, and directional proposals towards a resource-circulating society. It is also criticized for its lack of connectivity to the system of other laws regarding wastes. In order to formulate a resource-circulating society, the legal system needs to be established in a way that satisfies the two-way purpose of preventing environmental and health-related danger, and of efficient usage of resources. Importantly, more attention needs to be directed towards preparing effective and enforceable rules that can fundamentally restrict waste creation and promote circular utilization of resources. This paper sheds light on the state of the current legal system regarding wastes control after the enactment of the Framework Act on Resources Circulation and considers the relationship between wastes, recycling, and circular resources. Furthermore, it assesses the concept of extended producer responsibility within the Wastes Control Act as a potentially important means to achieve the purpose of a circular economy within a resource-circulating society. Lastly, the paper will touch on the shortcomings of the current legal system and discuss potential measures of legislative improvement regarding wastes control and resources circulation.

18-19세기 동ㆍ서양 세책(貰冊) 문화 연구 시론

이민희 열상고전연구회 2017 열상고전연구 Vol.58 No.-

본 연구는 전 세계 세책 문화의 특징을 밝히고자 한 시론에 해당한다. 세책(貰冊)을 하나의 문화현상으로 파악하고 세책 문화사가 독서 문화사와 밀접한 관련을 맺고 전 세계적으로 나타났음을 통시적 관점에서 고구하고자 했다. 세책 독서는 저렴한 값을 지불하고 일정한 대여 조건 하에 빌려다 읽는 새로운 독서방식을 의미한다. 18세기 들어 일반 독자가 독서의 주체로 급부상하면서 지식을 소유, 또는 공유하려는 의식이 강해졌다. 이때 원하는 책을 마음껏 사 볼 수 없는 독자는 책을 직접 구매하기보다 빌려 읽는 것을 선호하기 시작했다. 특별히 상품 가치가 높은 소설책 위주의 독서문화가 형성되면서 유럽(영국, 독일, 프랑스, 러시아, 슬로바키아 등)과 북미(미국, 캐나다), 그리고 동아시아(한국, 일본 등)에서 18-19세기에 공통적으로 세책 문화가 발달했다. 세책 문화는 오락성과 상업성을 토대로 책의 소비와 지식의 확산, 그리고 일반 독자가 출현해 만들어 낸, 독서사의 진보이자 동서양 공동의 보편적 문화유산이었음을 확인할 수 있다. 세계 여러 나라 세책 문화 사례를 통해 세책 문화의 형성 및 발달의 공통적 요소를 확인할 수 있다. 첫째, 세책업의 등장 및 발달의 중요 기반은 상업․경제적 요인에 있다. 돈(화폐)의 이용가능성이 높아지고 여가 시간의 증가, 그리고 소비 활동으로서의 독서 추구가 세책 문화를 만들어냈다. 둘째, 유럽과 북미, 그리고 동아시아 등 전 세계적으로 세책 문화가 공히 18-19세기에 융성했다는 점이다. 셋째, 특별히 소설 독서가 세책 문화 발달을 견인했다. 소설은 현실 문제와 연애담에 기반한 오락 및 교양 독서물 성격이 강한 서사였다. 기존 상층(귀족) 남성 독자와 달리 새로운 취향의 소설을 즐겨 찾는 시민과 여성 독자들이 세책을 통해 독서의 주체로 급부상하게 되었다. 넷째, 세책업은 일정한 경제 규모와 소비 활동이 가능한 대도시나 휴양지를 중심으로 발달했다. 다섯째, 도시 내 세책점의 위치 및 영업방식이 세책점의 성패를 좌우하는 요소였다. 여섯째, 일반 대중 독자의 의식 각성과 독서에 대한 인식 변화가 상업적 세책 문화를 이끌었다. 일곱째, 국가별 정치적 검열, 또는 서적 출판 및 유통 정책이 나라별 세책 문화의 성격 및 발달에 커다란 영향을 미쳤다. 여덟째, 전 세계적으로 19세기 후반-20세기 전반에 이르러 점차 세책업이 쇠퇴해 갔다. 이렇듯 전 세계적으로 보편적으로 나타난 세책 독서의 의미를 다음 몇 가지로 요약 가능하다. 첫째, 세책 독서는 여유가 있는 중간 독자층의 급성장과 소설 시대를 여는 촉매제 역할을 했다. 둘째, 독서를 매개한 의사소통의 변화를 가져왔다. 사회적, 시대적 요구와 독자의 취향을 반영한 독서물의 생산(출판, 필사)과 소비(독서) 활동은 독서 방법과 내용까지 결정짓는 요인이 되었다. 셋째, 독서 자체에 대한 인식의 변화를 가져왔다. 세책은 독서가 더 이상 진지한 학문 탐구 내지 종교적 수양 활동이 아닌, 일종의 소비 활동이자 개인적 여가 또는 취미, 교양 활동이라는 인식을 갖게 만들어 주었다. 넷째, 세책 문화는 사회 여러 분야에 걸친 융합 내지 결합을 이끄는 역할을 수행했다. 상층과 하층 독자를 하나로 묶을 수 있게 만들고, 남성 중심적 사회에서 그 차별적 경계를 허무는 역할을 했다고 평가할 수 있다. 이런 세책 문화는 전 세계적으로 공히 ‘신흥 독자층의 등장→소설의 성장→상업적 유통의 발달→문화 장려(출판 유통 검열의 완화) 정책→세책 독서의 발달’이라는 과정을 거치며 18-19세기에 그 꽃을 피울 수 있었다. 세책 문화가 발달하지 못했던 중국이나 유럽 중심부 국가들의 사정까지 살펴 세계 세책 문화의 제 특징을 아우르는 지형도를 구축하는 것이 필요하다. This study is an attempt to reveal the characteristics of the world circulating library culture. I tried to understand from the point of view that lending book was a cultural phenomenon, and that it was closely related to the history of reading and culture, and appeared worldwide. A reading by rent book means a new reading method that borrows books at a low price under certain rental conditions. In the 18th century, ordinary readers emerged as the subject of reading, and their consciousness to own or share knowledge became stronger. At this time, readers who can not buy the books they want are beginning to prefer borrowing rather than buying books themselves. In the 18th and 19th centuries it was common for general readers (especially female readers) to borrow various novels in Europe(Britain, Germany, France, Russia and Slovakia etc.), North America(USA and Canada), and East Asia(Korea and Japan etc.). It can be seen that the book circulating culture is the progress of the bookmaker and the universal cultural heritage of the East and the West shared by the consumption of books and the spread of knowledge based on entertainment and commerciality and the emergence of general readers. Through the common features found in the cases of various countries in the world, we examined the formation and development factors of the book circulating culture. As a result, firstly, commercial and economic factors were found to be important foundation for the appearance and development of book rental business. Increasing availability of money, increased leisure time and pursuing reading as a consuming activity have created a book circulating culture. Second, the book- borrowing culture in Europe, North America, and East Asia has flourished throughout the 18th and 19th centuries. Third, especially novel reading led to book rental cultural development. The novel was a narrative with a strong character of amusement and literary reading based on real problems and love stories. It was a change that appeared to be a new readership, a citizen and a female reader, who was able to read a novel of a new taste, to escape from the existing upper(noble) male reader, Fourth, in order to develop the book rental business, big cities and resort areas suitable for a certain economic scale and activities were suitable. Fifth, the location of the book rental store in the city also played a role in determining success or failure. Sixth, public conscious awareness of readers and changes in their perceptions of reading led to the borrowing of commercial goods through book stores. Seventh, political censorship or book publishing and distribution policies had a great impact on the development of book circulating culture. Eighth, the book rental business, which had been well into the 18th and 19th centuries, has gradually declined throughout the world from the late 19th century to the first half of the 20th century. In this way, we can summarize the meaning of book rental reading which is universally universal in the following several ways. First, the rental book reading acted as a catalyst to open up emerging of public readers and the era of the novel. Second, it brought about a change of communication through reading. The production of reading materials(publishing, mortal) and consumption(reading) in consideration of social and time demands and reader's tastes were factors that determine reading method and content. Third, it has changed the perception of reading itself. Book renting is a kind of consumption activity that makes reading more than a serious academic inquiry or religious fostering activity, but a lot of perception that it is personal leisure, hobby, and liberal activity. Fourth, the book circulating culture led to convergence and unification among the fields. The book rental activity was able to bind the upper and lower readers together and played a role in nullifying the discriminatory boundary in the male-centered society. This book circulating culture is common to all over the world:the emergence of new readers(female and lower readers)→the growth of novels→the development of commercial circulation→the promotion of culture (easing publishing censorship) →the development of reading through book borrowing It bloomed in the 18th and 19th centuries. It is necessary to build up a topography that covers the characteristics of the world book circulating culture by examining the circumstances of the central countries of China and Europe where the book circulating culture has not developed.

Characterization of fluidization regime in circulating fluidized bed reactor with high solid particle concentration using computational fluid dynamics

Benjapon Chalermsinsuwan,Theeranan Thummakul,Dimitri Gidaspow,Pornpote Piumsomboon 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.2

The hydrodynamics inside a high solid particle concentration circulating fluidized bed reactor was investigatedusing computational fluid dynamics simulation. Compared to a low solid particle reactor, all the conventionalfluidization regimes were observed. In addition, two unconventional fluidization regimes, circulating-turbulent anddense suspension bypassing regimes, were found with only primary gas injection. The circulating-turbulent fluidizationregime showed uniformly dense solid particle distribution in all the system directions, while the dense suspensionbypassing fluidization regime exhibited the flow of solid particles at only one side system wall. Then, comprehensivefluidization regime clarification and mapping were evaluated using in-depth system parameters. In the circulatingturbulentfluidization regime, the total granular temperature was low compared to the adjacent fluidization regimes. In the dense suspension bypassing fluidization regime, the highest total granular temperature was obtained. The circulating-turbulent and dense suspension bypassing fluidization regimes are suitable for sorption and transportation applications,respectively

순환유동층에서 하부 루프실 형태 변화에 따른 고체순환 특성 비교

이동호 ( Dong Ho Lee ),조성호 ( Sung Ho Jo ),진경태 ( Gyoung Tae Jin ),이창근 ( Chang Keun Yi ),류호정 ( Ho Jung Ryu ),박승빈 ( Seung Bin Park ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.4

연소전 CO2 포집용 SEWGS 시스템의 SEWGS 반응기와 재생반응기 사이의 고체순환을 위해 SEWGS 반응기 - 하부루프실 - 재생반응기 - 상승관 - 사이클론 - 상부 루프실로 구성된 순환유동층 시스템을 사용하고 있다. 현재 시스템의 경우 수직형 하부 루프실을 사용하고 있으나 하부 루프실의 유동화 및 안정적인 고체순환을 위해 유량이 많이 필요하고 가끔씩 슬러그가 발생하였다. 본 연구에서는 새로운 하부 루프실 형태로 경사형 하부 루프실을 제안하였으며, 상온, 상압 조건에서 CO2 흡수제(P-78)를 층물질로 사용하여 기포유동층-기포유동층-고속유동층 형태의 순환유동층 실험장치를 이용하여 하부 루프실의 형태 변화에 따른 고체순환특성을 측정 및 비교하였다. 경사형 하부루프실의 경우가 수직형인 경우보다 적은 유량으로 안정적인 고체순환을 유지할 수 있었으며 두 반응기 사이의 고체층 높이 차이도 발생하지 않는 것으로 나타나 경사형 하부 루프실을 사용하는 것이 유리한 것으로 결론지을 수 있었다. Circulating fluidized bed system consists of SEWGS reactor - lower loop seal - regeneration reactor - riser- cyclone - upper loop seal has been used for solid circulation between the SEWGS reactor and the regeneration reactor in a SEWGS system for pre-combustion CO2 capture. A vertical type lower loop seal has been used in current system but this lower loop seal requires high gas flow rate through the lower loop seal for fluidization and smooth solid circulation, and consequently, causes slugging behavior sometimes. To overcome these disadvantages, inclined type lower loop seal was proposed by this study. Solid circulation characteristics with change of lower loop seal geometry were measured and compared in a bubbling - bubbling - riser type circulating fluidized bed using CO2 absorbent (P-78) as bed material at ambient temperature and pressure. We could conclude that the inclined lower loop seal is better than the vertical type lower loop seal from the viewpoints of minimum flow rate requirement for stable solid circulation and solid height change during solid circulation.

봉산탈춤 팔목중과장의 순환구조로 본 구나성

김연진 ( Kim Yeonjin ),전은자 ( Jun Eunja ) 무용역사기록학회 2015 무용역사기록학 Vol.39 No.-

본 연구는 봉산탈춤의 제2과장인 `팔목중춤`의 생성적 의미구조와 순환구조를 분석하여, 이 과장을 통해 표현되는 구나(驅儺)의 특성을 살펴보았다. 구나는 역(疫: 염병 등 전염병)을 쫓는 행위 또는 그 의식을 말한다. 본 연구에 사용된 사진자료는 봉산탈춤 보존회에서 제공받은 1992년 5월 31일의 정기공연 영상이며, 이를 캡쳐하였다. 제2과장 팔목중춤을 3가지 구조유형으로 구분하였다. 우선 첫목중의 생성하는 구조; 둘째, 팔목중의 1:1 등·퇴장 구조; 셋째, 회무의 순환구조로 나누어 분석하였다. 그 결과는 다음과 같다. 첫째, 점진적인 움직임의 특징을 지니는 첫목중의 춤은 木의 오행 생성적 구조양상을 드러낸다. 음양적 교합 생성과 생장의 형상이자, 자연현상을 모방한 행위이다. 자연의 순환회귀 속에서 구나는 역이 스스로 물러나는 특성을 갖는다. 둘째, 팔목중춤은 1:1 등·퇴장 구조의 반복적 순환 속에서 구나성을 발견할 수 있다. 첫목중을 시작으로 팔목중까지 1:1로 계속 반복되는 등퇴장 구조는 음양의 순환관계를 표시한다. 서로 다른 성격을 지닌 목중들의 음양적 맞수를 통해 대대적이거나 교합하는 조화를 이룬다. 여기에서는 음양이 교체되는 모습을 통해 앞 시간은 뒷 시간에 밀려 스스로 쫓겨 물러나는 자연 순환을 상징한다. 이로써 앞 시간에 해당하는 역병은 뒤시간에 해당하는 왕성한 힘에 밀려서 쫓겨나는 자연의 구나성을 표현했다. 셋째, 팔목중의 `8`이라는 역수(易數)가 땅 위에서 원형으로 펼쳐져 돌아가는 순환의 원리가 포착된다. 선의 종시가 만나 원형을 이루며, 주이부시 순환을 행동하는 팔목중의 회무는 처용무에서 발견되는 계절이 지속적으로 돌아가는 자연모방의 순환을 닮았다. 처용무와 유사한 구나적 특성을 공유하고 있다. 그러므로 봉산탈춤 팔목중춤 과장에서는 자연의 순환구조가 춤의 중요한 양식이라는 점을 발견할 수 있다. 또 사계절의 치우치지 않는 올바름과 당당함을 표현한다. 이로써 역병은 앞선 계절의 헌것으로서 새것에게 자리를 내어주고 쫓겨 나갈 수밖에 없는 구조를 갖는다. 음양 간의 대대적 상태에서 힘(기운)을 소진한 역신(疫神)은 쫓겨 물러나고 왕성하게 충천하듯 들어오는 음양 교체는 곧 역신이 스스로 퇴장하는 동작으로써 구나적 특성이 표현됨을 나타낸다. 본 _______연구를 통해 한국의 봉산탈춤에 내재한 고유 사상을 이해하고자 노력했다. 우리 문화에 대한 이해의 다각적 시야를 확보하는 정점이 될 수 있기를 기대해 본다. This paper investigated the characteristics of guna, which are ritual actions to dispel epidemics, by analyzing the structure of formative meaning and circulation in palmokjungchum (the dance of eight mokjung), the second chapter of Korea`s traditional Bongsan mask dance. Figures in this research depict images of a dance performance that took place on May 31, 1992, which were provided by the Society for Preserving Bongsan Mask Dance. The second chapter of the dance was divided into three structural stages: an appearance of the first mokjung, the one-to-one entrance and exit of the eight mokjung, and the circulating structure of the rotating dance. The findings are as follows. First, the choreography of the first mokjung was incremental, representing the qualities of wood (木), which is one of the five primary elements. The dance during this stage embodies birth and growth through the union of yin and yang and emulates this natural phenomenon. Just as circulation is found in nature, epidemics retreat on their own accord during the ritual of guna. Second, the characteristics of guna are depicted by the one-to-one entrance and exit of the mokjung and by repetition of the same choreography. The entrances and exits are repeated, signifying the circulating relationship of yin and yang. The yin-yang juxtaposition of the mokjung is depicted by different characters, who go back and forth between confrontation and union. This alternation is indicative off the presence of circulation in nature, where time is continuously pushed back and replaced by subsequent time. This concept is represented by the character of guna, who dispels epidemics. Third, the number eight is the number of divination, and when laid out in circular forms, it illustrates the principle of circulation. The beginning and end of the line forms a circle, and the dance by the palmokjung incorporates continuous rotational moves (juibusi) that are reminiscent of the nature-emulating circulation observed in the Cheoyongmu (the dance of Cheoyong). The two dances share epidemic-dispelling characteristics. This indicates that in the second chapter of the Bongsan mask dance, nature`s circulation is a key motive for the choreography, which reveals the righteousness and confidence of nature, unbiased by any of the four seasons. Like nature, epidemics have a structure in which the old is inevitably replaced by the new. The primary characteristic of guna relates to how epidemics retreat from confrontation, where two opposing forces are not able to overcome the other, which is based on the principle of harmonious existence between yin and yang. The objectives of this study were to provide a more insightful understanding of the unique ideas and beliefs inherent in Korea`s traditional Bongsan mask dance and to provide a foundation for more diversified perspectives in the study and understanding of traditional Korean culture.

수도권매립지 활용에 따른 인천시 대응 방안

윤하연(Yun, hayeon) 인천연구원 2015 도시연구 Vol.- No.9

대량생산 대량소비 방식의 사회경제활동은 자원고갈, 다량의 폐기물 발생 등으로 인하여 환경부하가 가중되면서 자원절약, 폐기물 재활용, 매립 최소화 등 자원순환형 사회로의 전환을 요구받고 있다. 유럽의 경우 매립세 도입을 통한 매립억제를 통해 자원순환 극대화 전략을 쓰고있으며 독일은 자원생산성 국가목표를 설정하고 매립지침을 통하여 매립폐기물의 성상을 적극적으로 규제함으로써 자원의 선순환을 유도하고 있다. 우리나라도 자원순환 계획 수립을 통하여 자원순환 목표 설정, 폐기물 제로화 등 다양한 정책을 추진하고 있다. 최근 많은 논란 속에서 제한적 사용기간 연장을 합의한 수도권매립지 역시 자원순환형 폐기물관리 체계 구축을 위하여 매립폐기물 최소화, 매립지 환경 개선 및 효율적 매립지 관리 방안 도출 등 많은 과제를 안고 있다. 이에 본 연구에서는 국내외 폐기물 관리정책 동향과 수도권 매립지 현황 분석 등을 통하여 수도권매립지 활용에 따른 인천시 대응전략을 제시하였다. 구체적으로 자원순환 및 매립최소화를 위한 가연성 및 유기성 폐기물 직매립 금지와 매립기준 강화, 수도권매립지 주변지역 생활환경 개선을 위한 주변지역 지원확대 방안, 수도권매립지로의 폐기물 집중 억제를 위한 수도권매립지내 폐기물 중간처리시설 신·증설 금지 방안 등의 대응전략을 제시하였다. Faced with resource constraints, we are pressured to change mass production and mass consumption types of socio-economic activities into those proper in a resource circulating society, such as resource conservation, maximum recycling, minimum reclamation, in order to reduce the environmental load caused by the exhaustion of resources, and massive waste generation. Europe has facilitated resource circulation by imposing landfill tax and minimizing untreated wastes in the landfill. Germany regulates untreated wastes in the landfill by setting the national goal for resource circulation and eventually induce virtual resource circulation. Korea has also advanced plans for resource circulations such as setting a goal of resource circulation and realizing a zero-waste society. The Sudokwon(Capital Area) Landfill site are faced with many challenges, such as the minimization of landfill waste, the improvement of landfill environment, and the method to effectively manage the landfill for the establishment of resource-circulating waste management system. This research proposes a strategy for the Incheon City through the analysis of internal and external policy trends for waste management and the current state of Sudokwon landfill. Specifically, the reinforcement of reclamation standards and the prohibition of direct-reclamation for resource circulation and minimum reclamation, increasing assistance for a better living environments of neighboring regions, prohibiting the extension of waste treatment facilities within the Sudokwon landfill are suggested.

Circulating Tumor Cell and Cell-free Circulating Tumor DNA in Lung Cancer

Fariz Nurwidya,Jamal Zaini,Andika Chandra Putra,Sita Andarini,Achmad Hudoyo,Elisna Syahruddin,Faisal Yunus, M.D., Ph.D. 전남대학교 의과학연구소 2016 전남의대학술지 Vol.52 No.3

Circulating tumor cells (CTCs) are tumor cells that are separated from the primary site or metastatic lesion and disseminate in blood circulation. CTCs are considered to be part of the long process of cancer metastasis. As a ‘liquid biopsy’, CTC molecular examination and investigation of single cancer cells create an important opportunity for providing an understanding of cancer biology and the process of metastasis. In the last decade, we have seen dramatic development in defining the role of CTCs in lung cancer in terms of diagnosis, genomic alteration determination, treatment response and, finally, prognosis prediction. The aims of this review are to understand the basic biology and to review methods of detection of CTCs that apply to the various types of solid tumor. Furthermore, we explored clinical applications, including treatment monitoring to anticipate therapy resistance as well as biomarker analysis, in the context of lung cancer. We also explored the potential use of cell-free circulating tumor DNA (ctDNA) in the genomic alteration analysis of lung cancer.

Tumoral Accumulation of Long-Circulating, Self-Assembled Nanoparticles and Its Visualization by Gamma Scintigraphy

Cho, Yong-Woo,Kim, Yoo-Shin,Kim, In-San,Park, Rang-Woon,Oh, Seung-Jun,Moon, Dae-Hyuk,Kim, Sang-Yoon,Kwon, Ick-Chan The Polymer Society of Korea 2008 Macromolecular Research Vol.16 No.1

The enhanced permeability and retention (EPR) effect is used extensively for the passive targeting of many macromolecular drugs for tumors. Indeed, the EPR concept has been a gold standard in polymeric anticancer drug delivery systems. This study investigated the tumoral distribution of self-assembled nanoparticles based on the EPR effect using fluorescein and radio-labeled nanoparticles. Self-assembled nanoparticles were prepared from amphiphilic chitosan derivatives, and their tissue distribution was examined in tumor-bearing mice. The size of the nanoparticles was controlled to be 330 run, which is a size suited for opening between the defective endothelial cells in tumors. The long-circulating polymer nanoparticles were allowed to gradually accumulate in the tumors for 11 days. The amount of nanoparticles accumulated in the tumors was remarkably augmented from 3.4%ID/g tissue at 1 day to 25.9%ID/g tissue at 11 days after i.v. administration. The self-assembled nanoparticles were sustained at a high level throughout the 14 day experimental period, indicating their long systemic retention in the blood circulation. The ${\gamma}$-images provided clear evidence of selective tumor localization of the $^{131}I$-labeled nanoparticles. Confocal microscopy revealed the fluorescein-labeled nanoparticles to be preferentially localized in the perivascular regions, suggesting their extravasation to the tumors through the hyperpermeable angiogenic tumor vasculature. This highly selective tumoral accumulation of nanoparticles was attributed to the leakiness of the blood vessels in the tumors and their long residence time in the blood circulation.