혼합원자가 Sr_(1+x)La_(2-x)Fe_2O_(7-y) 훼라이트의 비화학양론 : 그 구조와 물리적 성질 Structure and Physical Properties

여철현,이성주,Grenier, Jean Claude 연세대학교 자연과학연구소 1985 學術論文集 Vol.14 No.-

Sr_(1+x)La_(2-x)Fe_2O_(7-y)계의 분말시료는 SrCO_3, La_2O_3및 Fe(NO_3)_3·9H_2O의 정량적 혼합물을 1350℃에서 24시간 가열하여 제조하였다. 이 분말시료를 펠�꼭�만들어 1450℃에서 24시간 동안 소결시켰다. 이 고용체의 결정구조는 x=0.0, 1.5, 1.7과 2.0인 경우는 정방정계였고, x=0.2, 0.5, 0.7, 1.0및 1.2인 경우는 사방정계였다. 각 계에 있어서 값이 증가할수록 격자체적이 감소함을 X-선 회절분석을 통하여 확인하였다. Mo¨ssbauer 스펙트라는 298K에서 측정하여 Fe^4+이온(δ=-0.24mm/sec)과 Fe^3+이온(δ=-0.23mm/sec)의 혼합원자가 상태를 확인하였다. 이 계의 Fe^4+이온과 Fe^3+이온의 혼합원자가 상태는 Mohr염 분석을 통하여 정량적으로 분석하였다. 비화학양론적 조성 y는 0.00에서 0.66사이의 값을 나타내었다. 시료의 전기전도도는 -100~140℃온도 범위에서 10^-9~1ohm^-1cm^-1의 반도체 영역에서 변하였다. 전기전도도의 활성화에너지는 0.47~0.14eV사이의 값을 나타내었다. 자기측정은 80K에서 1273K사이의 온도범위에서 실시하여 Ne´el온도는 Sr_3Fe_2O_6.90의 경우 130K 이었고, 그 값은 X값이 감소함에 따라 증가하였다. The powder samples of the Sr_(1+x)La_(2-x)Fe_2O_(7-y) system are prepared from stoichiometric mixtures of SrCO_3, La_2O_3, and Fe(NO_3)_3·9H_2O by heating at 1350℃ for 24 hours. The pellet samples are sintered at 1450℃ for 24 hours. The crystallographic structures of the solid solutions of x=0.0, 1.5, 1.7 and 2.0 are tetragonal systems and those of x=0.2, 0.5, 0.7, 1.0 and 1.2 are orthorhombic systems. In each systems, X-ray diffraction analysis reveals that the unit cell volume decreases when the x value is increased. Mo¨ssbauer spectra measured at 298K indicates that isomer shift of iron (Ⅳ) in x=2.0 is-0.24mm/sec and that of iron (Ⅲ) is 0.23 mm/sec. The mixed valency state at two kinds of Fe ion in the solid solutions is quantitatively analyzed by the Mohr salt titration method. The value of nonstoichiometric ratio y is varied from 0.00 to 0.66. Electrical conductivities of this systems are measured in a temperature range of -100 to 140℃. The conductivity values are vared from about 10^-9 to 1 ohm^-1 cm^-1 within semiconductivity range. Activation energies of electrical conductivity are varied from 0.47 to 0.14 eV. Magnetic mesurement indicates that Ne´el temerature is 130K in Sr_3Fe_2O_6.90 and increases when the x value is decreases.

South Africa's Public Debt: Long-term Dependence, Structural Breaks and Multifractality

Jean-Claude Kouakou Brou,Jamal Bouoiyour 세종대학교 경제통합연구소 2023 Journal of Economic Integration Vol.38 No.4

This paper aims to analyse the evolution of public debt in South Africa using new and original methods. The case of South Africa has been little studied in the literature on debt because the level of debt in this country remains reasonable. Moreover, the use of non-standard methods allows for a fine-grained analysis of the public debt time series and, consequently, to draw unprecedented conclusions. Using the Multifractal Detrended Fluctuation Analysis (MF-DFA) method borrowed from solid state physics and medicine, we conclude that South Africa's debt has a multifractal character, which originates from the long memory effect. Thus, South Africa's public debt is unsustainable. The inefficiency of this market has been particularly exacerbated by the various shocks throughout the sample period.

POTENTIAL APPLICATIONS FOR NUCLEAR ENERGY BESIDES ELECTRICITY GENERATION: A GLOBAL PERSPECTIVE

JEAN-CLAUDE GAUTHIER 한국원자력학회 2007 Nuclear Engineering and Technology Vol.39 No.1

Energy supply is increasingly showing up as a major issue for electricity supply, transportation, settlement, and process heat industrial supply including hydrogen production. Nuclear power is part of the solution. For electricity supply, as exemplified in Finland and France, the EPR brings an immediate answer; HTR could bring another solution in some specific cases. For other supply, mostly heat, the HTR brings a solution inaccessible to conventional nuclear power plants for very high or even high temperature. As fossil fuels costs increase and efforts to avoid generation of Greenhouse gases are implemented, a market for nuclear generated process heat will be developed. Following active developments in the 80’s, HTR have been put on the back burner up to 5 years ago. Light water reactors are widely dominating the nuclear production field today. However, interest in the HTR technology was renewed in the past few years. Several commercial projects are actively promoted, most of them aiming at electricity production. ANTARES is today AREVA’s response to the cogeneration market. It distinguishes itself from other concepts with its indirect cycle design powering a combined cycle power plant. Several reasons support this design choice, one of the most important of which is the design flexibility to adapt readily to combined heat and power applications. From the start, AREVA made the choice of such flexibility with the belief that the HTR market is not so much in competition with LWR in the sole electricity market but in the specific added value market of cogeneration and process heat. In view of the volatility of the costs of fossil fuels, AREVA’s choice brings to the large industrial heat applications the fuel cost predictability of nuclear fuel with the efficiency of a high temperature heat source free of Greenhouse gases emissions. The ANTARES module produces 600 MWth which can be split into the required process heat, the remaining power drives an adapted prorated electric plant. Depending on the process heat temperature and power needs, up to 80 % of the nuclear heat is converted into useful power. An important feature of the design is the standardization of the heat source, as independent as possible of the process heat application. This should expedite licensing. The essential conditions for success include: Timely adapted licensing process and regulations, codes and standards for such application and design An industry oriented R&D program to meet the technological challenges making the best use of the international collaboration. Gen IV could be the vector Identification of an end user (or a consortium of) willing to fund a FOAK

AN ADMINISTRATIV ETHICS PRESCRIPTION FOR PUBLIC BUREAUCRACIES

Jean-Claude Garcia-Zamor The Research Institute for Public Administration H 1997 The Annals of Public Administration Research Vol.15 No.-

프랑스의 방사성폐기물정책과 국민적 합의

Jean Claude Guais 한국원자력산업회의 1992 원자력산업 Vol.12 No.8

Social Equity in Urban Development. The Leipzig Experience.

Jean-Claude Garcia-Zamor 한국행정학회 2009 International Review of Public Administration Vol.14 No.2

The article examines a unique experience in applying social equity in urban development in the city of Leipzig in the former East Germany. During the socialist era, many had fled to the West leaving Leipzig with many empty homes and office buildings. Recently, city officials took advantage of the situation as an opportunity to initiate a period of social transformation. They developed a plan to reposition a city with a surfeit of buildings and space in such a way as to preserve the qualities of that city, seize the opportunities presented by the transformation, and ensure that the city remains exciting, safe, and attractive for its inhabitants. Key projects were initiated to allow people in need of low-cost housing to use legally vacant dwellings. The strategy adopted by Leipzig is not a universal model that can be applied to all cities since each city has its own socio-economic, political, and legal systems that provide a framework for workable solutions. But the way Leipzig faces its challenge could be an inspiration for other cities that might want to borrow only some of the transferable features of the Leipzig solution to design their own responses to a similar problem.

Camembert Cheese: Technology, Microbiology, Biochemistry

( Jean Claude Gripon ) 한국유가공기술과학회 2006 Journal of Dairy Science and Biotechnology (JMSB) Vol.24 No.2

A study of the relevance of an acoustic holography method using wavelets based on features extracted from wavenumber spectra

Jean-Hugh Thomas,Jean-Claude Pascal 한국소음진동공학회 2003 한국소음진동공학회 국제학술대회논문집 Vol.2003 No.8

Three Decades of Hardware Description Languages in Europe

Jean Mermet,Peter Marwedel,Franz J. Ramming,Cleland Newton,Domminique Borrione,Claude Lefaou 한국정보과학회 1998 Journal of Electrical Engineering and Information Vol.3 No.6

This paper binds together a collection of short presentations on Hardware Description Languages(HDLs) developed in Europe and provides a view of the history of HDLs during the last three decades. This historical review wants to present the ideas, conceived in these previous languages, which are now implemented in the standard languages. Furthermore, this paper will highlight those early concepts which yet need to be implemented in the evolving standards or could provide a way to unify them (like VHDL or Verilog or SDL) within a formally defined multi-language environment. Among a large number of European works over 3 decades, we have selected a sample from different countries France, Germany, U.K, Italy, which have been implemented and used reliably in various segments of the industry. The selected HDLs, with the date of origination, are: CASSANDRE (1967), MIMOLA (1977), DACAPO (1977), ELLA(1979), ART (1980), and CASCADE (1981). We do not pretend to any exhaustive review, which is not the goal of this presentation, and have consciously left aside several works as valuable as those selected. We have not addressed for example ≪ synchronous languages ≫ very well developed in France, such as ESTEREL, LUSTRE or SIGNAL. Several other works existed in Germany, such as KARL, which was popular in the eighties, and benefits from a large bibliography or REGLAN. We should mention also among those HDLs not presented here CONLAN (a major international standardization effort involving a notable European contribution). We have tried to compare the main features of the chosen languages according to a list of criteria and briefly identify those which are still missing in the recognized worldwide standards.

LES POLLUTIONS MARINE-CONTROLE STRATEGIE

Jean Claude Oppeneau 대한환경위생공학회 1992 대한환경위생공학회 기타 간행물 Vol.1992 No.1