bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Crack Propagation along Bond Coat/Topcoat Interface of a TBC System
Authors: Gomez B. , Miyashita Yukio , Mutoh Yoshiharu , Takahashi M.
Published: March 2009

The crack propagation along the bond coat / topcoat interface of a TBC system has been studied in a previous work under a certain mode ratio (K2/K1). In order to discuss a parameter that
describes the crack propagation, the growth behavior of a crack has to be studied under various K2/K1 ratios. In this work, BEM was used to determine the modifications that change K2/K1 ratios of the specimen employed in the previous study. Six characteristics of the specimen were modified: location of the applied load; height; length, position and direction of the notch, and its
separation from the bond coat / topcoat interface. Among these modifications, the change of location of load point can effectively change K2/K1 ratio to values greater and smaller than those of the previous study.
Crack propagation tests with three different positions of load point were performed using
specimens with topcoat porosity of 5%, 15% and 20%. The results indicated that, independently of K2/K1 ratio, the parameter Ki dominated the crack growth behavior for an interface crack under
mixed mode.
An Improved FOSM Method for Calculating the Failure Probability of Welded Pipes with Cracks
Authors: Huo Li Xing , Liu Min , Zhang You Feng , Qi Fang Juan
Published: March 2009

To increase the accuracy of R-F method, it is necessary to solve the problems of the linear expansion of failure function and non-normal variables. In this paper, the improved FOSM method was applied to calculate the failure probability of welded pipes with cracks. The examples show that this method is simple, efficient and accurate for reliability safety assessment of welded pipes with cracks. It can save more time than the Monte Carlo method does, so that the improved FOSM method is recommended for general engineering reliability safety assessment of welded pipes with cracks.
Synthesis of Phosphorescent Platinum Complexes with 3-Aryl Pyridazine as Prominent Emitting Materials in Organic Light-Emitting Device
Authors: Lee Seung Hee , Han Won Hee , Shin Hyun Seo , Lee Sang Jin
Published: March 2009

The synthesis and characterization of a series of square planar Pt(II) complexes, which are luminescent at room temperature, are reported. The complexes have the general structure of (C^N)Pt(O^O), where HC^N is 3-phenylpyridazine (ppdz), 3-(4’-biphenyl)pyridazine (4’phppdz), 3-(2’-naphthyl)pyridazine (2’napdz), or 3-(1’-naphthyl)pyridazine (1’napdz), and HO^O is acetylacetone (Hacac). The reaction of K2PtCl4 with HC^N forms the chloro-bridged dimer, (C^N)Pt( µ-Cl)2Pt(C^N), which are cleaved with an ancillary ligand to give the corresponding monomeric (C^N)Pt(O^O) complexes. The emission bands of these complexes are governed by the structure of the cyclometalating ligands, with emission band (lem) ranging from 516 to 645 nm. The two emission bands at (515 and 550 nm) of (ppdz)Pt(acac) complex have 7 and 6 ms of life time which imply those bands are due to phosphorescence decay. The conjugating ring on the pyridazine makes the emission more red shifted which is expected based on molecular orbital calculation. In addition to the alteration of cyclometalating ligands, ancillary ligands also change. These results can be compared with the corresponding Ir(III) complexes.
Preparation of a Photobleacheable Dye Capsule Nanocomposite for Reusable Recording Media
Authors: Oh Hyunsuk , Kim Eunkyoung
Published: March 2009

A new photobleacheable nanocomposite was developed as a reusable recording media. It is composed of polymer dye capsules containing TiO2 nanoparticles, leuco dyes, and a developer. The polymer dye capsules were prepared using the convenient one-step mini-emulsion polymerization. The morphology of the resultant polymer dye capsules were examined through a scanning electron microscopy (SEM), to show the capsule structure, which averaged 30~ 500 nm in size. The leuco dye was originally colorless, but it acquired color when it reacted with the developer. The blue colored dye capsule solution was stable under ambient conditions and could thus be utilized as a recording composition. The color of the recorded part, by coating the dye capsule solution on to a piece of white paper, was persistent. However, the recorded mark was bleached upon exposure to a UV light. Capsule morphology was not detected in the bleached region as examined by a SEM, indicating that titanium dioxide in the film acted as a photocatalyst to decompose the capsule structure. The bleaching was irreversible so that the recording media was reusable. The bleaching efficiency in photobleaching was shown to be higher than 75%.
Two Excited State Structures of Donor-Acceptor Substituted "Proton Sponge"
Authors: Szemik Hojniak A. , Deperasińska I. , Buma W.J. , Balkowski G. , Pozharsky A.F. , Vistorobskii N.V.
Published: March 2009

Photoexcitation of “proton sponge” 1,8-bis (dimethylamino) naphthalene (DMAN) leads to charge transfer (CT) emission. This work demonstrates that substitution of DMAN with a strong electron acceptor group (CN) results in CN-DMAN and leads to a stronger orbital decoupling between the Donor and Acceptor groups and to a more effective CT process (λF = 630 nm). The theoretical absorption spectrum calculated for CN-DMAN using the ZINDO method on its ground state ab initio [HF/6-31G(d)] optimized geometry reproduces a better experimental spectrum than that calculated using the RCIS method. It also shows that AM1 excited state (1La) optimization reveals two quasi-degenerated states with anti-quinoidal (A) and quinoidal (B) structures and the CT nature. Both structures may contribute more or less equally to the fluorescence of CN-DMAN in
a solution.
Tissue-Engineered Skin Substitutes Using Collagen Scaffold with Amniotic Membrane Component
Authors: Yang Eun Kyung , Park Jung Keug , Ahn Jae Il , Lee Hee Gu , Seo Seong Jun , Son Dae Gu , Kim Jae Chan , Song Kye Yong
Published: March 2009

Human skin substitutes are needed for implantation and wound repair based on the new concept of tissue engineering in combination with biomaterials and cell biological technology. However, failure sometimes occurs when the wound healing is delayed in vivo due to acute inflammation resulting from the early degradation of the transplanted biomaterials. Accordingly, the current study modified conventional biomaterials to overcome early degradation and strong inflammation. In a conventional skin substitute, the animal origin collagenous materials have a
slight antigenicity as xenogenic materials, however, the modified method was able to obtain a low antigenicity and anti-inflammation effect using atelo-collagen and an amniotic component. The tyrosine content in the developed atelo-collagen, representing the antigenicity, was reduced from 0.590% to 0.046% based on an HPLC analysis. In addition, to reduce the inflammation and foreign material reaction, an amniotic component was applied to the atelo-collagen materials. While, to
enhance the wound healing, the modified skin substitute was developed as a composite matrix of an atelo-collagen scaffold with an amniotic membrane component. A quantitative analysis of hEGF in the amniotic membrane was also performed using different processing methods. Finally, a tissueengineered
skin substitute was constructed by cultivating skin cells in the collagen scaffold attached to an amniotic membrane.
Acupuncture Meridian and Intravascular Bonghan Duct
Authors: Baik Ku Youn , Lee Ja Woong , Lee Byung Cheon , Johng Hyeon Min , Nam Tae Jeong , Sung Baeckkyoung , Cho Sung Il , Soh Kwang Sup
Published: March 2009

Current anatomical theory does not recognize the existence of an extended floating
threadlike structure inside the blood vessels. Nonetheless, this study developed a new method for observing such an intravascular threadlike structure. The key technique involves injecting acridineorange into the femoral vein to circulate along the blood vessels and stain the nuclei of the intravascular threads inside the blood vessels. In-situ observations were then made under a fluorescence stereomicroscope after saline-perfusion. Confocal microscope images revealed a
distinctive characteristic pattern of nucleus distribution that was clearly distinguishable from fibrin, capillaries, small venules, arterioles, or lymph vessels. Accordingly, it is suggested that the identified intravascular threads are part of the Bonghan's circulatory network that is distributed throughout the body, including inside the blood vessels.
An Optimal Estimator Model of Multi-Sensory Processing in Human Postural Control
Authors: Park Suk Yung , Kuo Arthur D.
Published: March 2009

We hypothesized that multi-sensory processing at the central nervous system (CNS) in human postural control can be described using an optimal estimator model. The estimates on body dynamics from multi-sensory signals contain sensory noise, transmission delays, and process disturbances. The state estimates approximate actual body movement. Erroneous estimates degrade the performance of feedback control and could cause a loss of balance if distorted severely. To test the hypothesis, we examined the frequency response of a visually-induced postural sway with stimulus frequency ranging from 0.075 to 1Hz and established an optimal estimator model. Two healthy young (33yrs ± 1) subjects stood on a force platform located 1.25m behind a projection screen with their arms crossed over their chests. They were asked to maintain an upright posture against the sinusoidal visual field stimuli. Each sinusoidal visual stimulus was generated by a projector for 200secs in pitch direction with a maximum pitch angle of 20o. Kinematics data was recorded to calculate the frequency response function of the center of mass (COM). There were three components in the modeling procedure: a biomechanical model of body and sensor dynamics, a linear feedback control model to stabilize the biomechanical model, and a state estimator to estimate body dynamic states based on multi-sensory outputs. We modeled the sensor dynamics of the semicircular canal, otolth, vision, and muscle spindles at the ankle and hip joint. We used the Kalman filter and linear quadratic regulator to determine feedback gains. Results showed that the frequency response function of a visually-induced postural sway decreased as stimulus frequency increased, and this low-pass filtering characteristic with an approximate cutoff frequency of 0.2Hz was also simulated by the postural feedback control model with optimal estimator. Low-pass filtering characteristics of the frequency response are mainly due to body and sensor dynamics, which show reduced responses for high frequency stimulus. The
Kalman filter represents that the CNS utilizes redundant sensory information in a way that minimizes discrepancies between actual body dynamics and estimated body dynamics based on sensory output and an internal model. The results suggest that the CNS may make use of an internal representation of body dynamics, and can integrate sensory information in an optimal way to best estimate human postural responses.
Model of Women's Informatization Indicator
Authors: Kim Kio Chung , Kim Yong Ja
Published: March 2009

The framework for a women's informatization indicator (WII) was developed. The
previous indicators focused on the infrastructures of the country and not on the perceptions and behaviors of individual members of the information society. This study has included the objective and subjective aspects of the informatization of individuals. The weights (coefficients) of influencing factors were obtained from multiple regressions of the survey data. The comprehensive indicator for the women’s informatization level is earned. Finally, WII was transformed into the
index. This index makes it easy to compare diverse groups over certain periods of time.
Context-Aware Recommendation Using Pattern Discovery in Ubiquitous Computing
Authors: Kwon Joon Hee , Kim Sung Rim
Published: March 2009

Ubiquitous computing requires an intelligent environment and context-aware
recommendations. This paper describes context-aware recommendations using pattern discovery in ubiquitous computing. The proposed method recommends information that may be useful without requiring any action on the part of the user by changing the user’s context. To recommend information, we discovered interesting patterns between past experiences and the current context. We explained the process, the algorithms and gave an example. Several experiments were performed and the results showed that our method has a good recommendation performance.
Houses for an Information Society by Interpretation of Traditional Korean Houses
Authors: Kim Jong Hun
Published: March 2009

An information-intensive society should be supported not only by the development of computer hard/software, but also by the entire social structure, including practical living conditions such housing structures. Therefore, it is inevitable that housing styles should change in relation to new demands in the living and working environment that result from the development of an information-intensive society. The
alternatives suggested by this study refer to traditional Korean houses as a means of setting some physical distances between the workplace and living area in the same unit building; differences in the level between 'home space' and 'office space', differences in materials used (wood, concrete, etc.,), and in particular, the method of access whereby dwellers should go out and come in to enter the 'office space', are all explored. We have also referred to the unique Korean custom of removing our shoes to enter another space. Furthermore, the concept of containing a social space in the living space of a traditional Korean house was reinterpreted to suggest that the traditional Korean house is a prototype that is suits the living and working needs of our information-intensive society. In this view, 3 types of houses are presented: the flat type, the tower type and the skip floor type. These houses have two independent entrances for the home space and the work space thereby providing a separate, efficient place to work from home.
A Protein Structure Retrieval System Using 3D Edge Histogram
Authors: Park Sung Hee , Park Soo Jun , Park Seon Hee
Published: March 2009

This paper proposes a novel protein structure descriptor (or representation) and its application for structure comparison. Since the functions of protein may come from its structure, the method of measuring structural similarities between two proteins can infer their functional closeness. In this paper, we have developed a novel descriptor (3D edge histogram) to compare the structures of proteins. The 3D edge histogram is a local distribution of bonds between the atoms in a protein. We have designed and implemented a protein structure retrieval system based on the 3D edge histogram to demonstrate that it could be effective in protein structure comparison. In this system, principal component analysis for aligning, voxelization for volume generation, quantization, 3D edge extraction, and comparison of 3D edge histogram are performed. The protein structure retrieval system using the 3D edge histogram shows fast retrieval with relatively precise results. It can be used for pre-screening purposes with a huge database.
Improvements in Real-Time Feature-Based License Plate Character Recognition
Authors: Ko Mi Ae , Kim Young Mo
Published: March 2009

This paper presents an effective method for segmenting and recognizing license plate characters on a moving vehicle in actual outdoor environment. It is applicable to various camera conditions and installation environment and provides some effective methods to improve the rate of recognition and procedure speed. This paper is concerned not only implementations in laboratory environment but also in outdoor environment like roads, entrances of parking areas and other similar places where license recognition is needed. The digital images used can be obtained from any digital camera. The proposed vehicle license plate character recognition methods are constructed from a feature-based approach. By regulating a character, a unique structural feature for each character can be extracted. The extracted feature is insensible to changes in the outdoor environments. The proposed recognition system has two main processes: 1) to construct the feature information and 2) to segment a character image from any object image of a license plate and identify it. The relative regulations, the similarity and dissimilarity between each character, are used as recognition features.
Role of Additives in Tin Oxide-Based Sensors for Alcohols
Authors: Cheong Hae Won , Kim Hee Sook Park , Yoon Ki Hyun
Published: March 2009

Using gas chromatographic analyses, the effects of additives (PdCl2, Al2O3, or La2O3) on the alcohol sensing properties of SnO2-based sensors were investigated with respect to the distribution and the reaction steps of the products formed from the reactions of alcohols over the SnO2-based powder. Ethanol was catalytically oxidized with the SnO2-based powders. With the PdCl2-doped SnO2, the C–C bond cleavage product, methane, was produced. This seems to be related
with the significant promotional role of PdCl2-doping in ethanol sensing especially at temperatures below 300 oC. For the La2O3-doped SnO2, relatively large amounts of CO and CO2 were produced, resulting in an enhanced sensitivity. On the other hand, for the Al2O3-doped SnO2, selective dehydration, which consumes smaller amounts of the adsorbed oxygen species (O- ads), seems to degrade the sensitivity. When exposed to methanol, the SnO2-based sensors showed oxidation
products consisting of CO, CO2 and H2O and sensing characteristics similar to those observed with ethanol.
A Study of the Biosorption Characteristics of Co2+ in Wastewater Using Pseudomonas Aeruginosa
Authors: Kang So Young , Lee Jong Un , Kim Kyoung Woong
Published: March 2009

Pseudomonas aeruginosa biomass was used to investigate the biosorption properties of heavy metals in wastewater. The biosorption isotherm of Co2+ was best described by the Langmuir model when washed cells were employed, and results obtained utilizing heat-treated P. aeruginosa were also adequately represented by a Langmuir sorption isotherm. In contrast, the sorption isotherm involving unwashed P. aeruginosa showed a different isotherm profile and did not attain equilibrium in the range of metal concentrations investigated; the amount of Co2+ uptake increased with increasing initial metal concentration but never reached adsorption equilibrium, most likely due to bacterial production of extracellular polymeric substances (EPS). The biosorption results utilizing unwashed P. aeruginosa were best described by a Freundlich isotherm. The level of metal
adsorption in low pH was significantly small due to competition between the cation and H+ ions for binding sites distributed on cell surfaces, while the increase in pH favored metal sorption because of the elevated quantities of negatively charged surface functional groups. The sorption of Co2+ was strongly influenced by the presence of competing cations in the solution. Trivalent Cr3+ added to the solution was preferentially adsorbed onto the cells relative to Co2+ and Ni2+. The results may be attributed to the higher adsorption affinity of Cr3+ in comparison to either Co2+ or Ni2+. The affinity order (Cr3+ > Co2+ » Ni2+) was maintained over a pH range up to 5.3 in a mixture solution.
Anodic Degradation of Toxic Aromatic Compound in the Flow Through Cell with Carbon Fiber Electrode
Authors: Yoon Jang Hee , Jeong Euh Duck , Shim Yoon Bo , Won Mi Sook
Published: March 2009

The anodic degradation of aqueous phenol and 2-chlorophenol, which are model organic pollutants, has been studied using a flow-through electrochemical cell (FTEC) with carbon fibers as an anode material. For a controlled current electrolysis of an aqueous solution of 2-chlorophenol and phenol, experimental variables, including such as, the current input, the reaction time, and the flow rate of the solutions were considered. The degradation products of the oxidation reactions were identified with HPLC, GC/MS. Small aliphatic acids and CO2 were the main products. Depending on the values of the applied current and reaction time, a complete degradation or the partial oxidation of the compounds to other intermediates was obtained. At the flow rates of 2-6 mL/s were effective on the degradation efficiencies of the 2-chlorophenol and phenol.
Carbon Isotope Ratio Measurement on Foxtail Seed as an Environmental Index
Authors: Park Soo Young , Kim Jin Seog
Published: March 2009

The carbon isotope ratios in foxtail seeds, which grow well anywhere such as a
residential street, roadside, empty lot, field etc., were measured by EA/IRMS (Elemental Analyzer/ Isotope Ratio Mass Spectrometer). The samplings were carried out in two ways. One set of foxtail seeds was sampled at 11 different locations to examine the effect of the traffic frequency in Daejeon and its suburbs. The other set was collected in three separate areas to examine the distance effect
from the roadside. The d13C values of foxtails were increased at a distance from the center of Daejeon City. According to the results for the other set to examine the distance effect from the roadside, the d13C values of foxtails grown close to the roads were lower than those far away from the road. It means that the roadside foxtails are highly affected by automobile exhaust gases. This effect strongly decreased as the distance from the road increased, because the pollution gases by the vehicles diluted well with the air, even at 5 m from the road. We propose that these results can be used in the monitoring of the hazardous atmospheric pollutants caused by fossil fuel in addition to the monitoring of carbon dioxide.
Toxic Risk Assessment and Environmental Contamination of Heavy Metals around Abandoned Metal Mine Sites in Korea
Authors: Lee Jin Soo , Chon Hyo Taek , Jung Myung Chae
Published: March 2009

In order to investigate the levels of heavy metal contamination and to assess the risk of the adverse health effects on human exposure to toxic heavy metals influenced by past mining activities, environmental geochemical surveys were undertaken around abandoned metal mine sites (Okdong Cu-Pb-Zn, Dokok Au-Ag-Cu and Hwacheon Au-Ag-Pb-Zn mines). High concentrations of heavy metals were found in tailings from the Okdong (72 As mg/kg, 53.6 Cd mg/kg, 910 Cu mg/kg, 1,590
Pb mg/kg, 5,720 Zn mg/kg), the Dokok (254 As mg/kg, 98.2 Cd mg/kg, 2,550 Cu mg/kg, 4,200 Pb mg/kg, 18,020 Zn mg/kg) and the Hwacheon (72 As mg/kg, 12.4 Cd mg/kg, 580 Pb mg/kg, 1,300 Zn mg/kg) mines. Elevated levels of As, Cd, Pb and Zn were also found in agricultural soils from these mine areas. Human risk effects are classified into a cancer effect and a toxic (noncancer) effect. The
hazard index representing a toxic risk for As was higher value than 1.0 in the Okdong and the Hwacheon mine sites, as was that for Cd in the Okdong and Dokok mine sites. Therefore, toxic risks for As and Cd exist via exposure (ingestion) to the contaminated soil, groundwater and rice grains in these mine areas. The cancer risk for As by the consumption of groundwater used as drinking water from the Okdong and the Hwacheon mine areas was 7E-4 and 1E-4, respectively. These risk levels exceed the acceptable risk (1 in 100,000) for regulatory purposes.
Growth and Reproduction of Porphyra Kuniedae Kurogi (Bangiales, Rhodophyta) from Korea
Authors: Hwang Mi Sook , Kim Jin Koo , Sim Doo Saing , Oh Yoon Sik , Choi Han Gu
Published: March 2009

Growth and reproduction of Porphyra kuniedae from the southern coast of Korea were investigated. Biomass, plant size and occurrence of reproductive structures were monitored every other week from November 2001 to March 2002. Release of zygotospores and monospores from the plants was induced and the number of spores was counted in the laboratory culture every month. Biomass and plant size were found to be inversely correlated with water temperature. The maximum values in biomass and plant size were observed in mid-January with the lowest water temperature, and the values decreased with the increase of water temperature. Based on the cohort analysis, three cohorts started in late November, one to two cohorts were added every other week, and the maximum was eight in mid-January. The percentage of matured plants in the field was the highest in January. In the laboratory culture test, zygotospores were released more than monospores from large plants in late December while monospores were released much more than zygotospores since late January.
Development of a High Power Li/SOCl2 Reserve Battery
Authors: Kim Hee Sook Park , Cho S.B. , Koo Bon Soon , Kim Jong Myong , Cheong Hae Won , Yoon Eul Jae , Ryu Byung Tae , Lee Sang Jin , Lim Byung Ju , Ko Young Ok
Published: March 2009

We have tried to develop a lithium/thionyl chloride reserve battery (560W). A cell consists of 5 double-sided cathodes and anodes (toroidal shape, electrode area: 100 cm2, cell surface area: 900 cm2, current density: 22mA/cm2). We have designed a unique internal serial connection, which is capable of obtaining a desired voltage by simply stacking the cells and then tightening the internal serial connection
volts. A piston-type electrolyte reservoir is designed. Our dual-piston electrolyte reservoir requires smaller space for the piston movement than a single-piston reservoir. It also renders reliable opening of the diaphragm, and appropriate electrolyte transferring speed to avoid damage to the carbon electrodes. The batteries underwent performance tests, environmental tests, and accelerated aging test.
Life Cycle Assessment(Lca) of the Power Generation System for the Establishment of Environmental Management System in Korea
Authors: Lee Young Eal
Published: March 2009

The development of electricity technology from the environmental aspect has become the key factor for competitiveness, i.e., environmental friendliness is one of the most important considerations for technology development. Under the monopolised electric industry of the past, there was little motivation for individual companies to actually manage their company. However, because of the increasing demand for energy and the concerns for the environment, energy policies are shifting towards a sustainable development, which considers both the economics and
environmental protection. According to the paradigm shift of the energy policy, it is necessary to compare two major electricity sources from the view of environmental management issues. It is effective with the common dimensionless unit concerning the various environmental categories including the radiological and non-radiological points of view, which can be realized by the new environmental impact assessment methodology such as the Life Cycle Assessment (LCA). This study aims at a comparison of the environmental impacts of the nuclear and coal power generation
systems using the LCA methodology. These results are very preliminary ones, however, this study will be helpful in making a decision on a long term electricity plan and the energy mix optimization when considering the environmental aspect in Korea and also the power generation companies could enhance their images by showing off their willingness to improve the environmental quality.
Production and Amyloid Fibril Formation of Recombinant Yeast Prion(Sup35)-Like Protein Fragment
Authors: Kim Yongae , Kim Yuna , Park Jae Joon , Hwang Jung Hyun , Park Tae Joon
Published: March 2009

Amyloid fibrils have long been established as the well-known a-helix to b-sheet
transition that characterizes the conversion of the cellular form of prion proteins into a scrapie form. A very short sequence of the Yeast prion-like protein GNNQQNY(SupN) is responsible for the aggregation that induces diseases. As such, in the current study, a GST-fused monomer SupN vector is used to express the SupN peptide in Escherichia coli(E. Coli). In addition, a method for the production, purification, and cleavage of the recombinant SupN in E. coli is also described, which yields as much as 2mg per liter of growth of natural abundance fusion proteins in LB media. To gain a better understanding of the aggregation-structure relationship of the 7 residues of the Yeast prion-like protein, the change in the conformational structure is studied by Transmission Electron Microscopy and will be further studied by 13C solid-state NMR. Accordingly, this is the first investigation of the fibril formation of a heptamer peptide expressed in E.coli.
Analysis of Chromosome Lesions in Women with Benign Breast Diseases, Residing in the Territories Contaminated as a Result of the Chernobyl Accident
Authors: Ivanova T. , Smirnova I. , Kondrashova T. , Yun Yeon Sook , Song Jie Young , Han Young Soo
Published: March 2009

Spontaneous levels of the chromosome aberrations in the peripheral lymphocytes of 173 women were analyzed in the course of a medical examination of the residents of the Bryansk District territories (Klintsy Region, and the town of Klintsy) contaminated after the Chernobyl NPP accident in April 1986. The study population included only women who had been premenopausal at the time of the accident (mean age in 1986 was 23.9±0.7 years, ranging 2 to 56 years). The territory
contamination with 137Cs ranged from 1.8 to 23.7 Ci/km2, the mean value being 7.5±0.2 Ci/km2. The range of the calculated absorbed thyroid doses was 30 to 340 mGy (in average, 52.3±3.3 mGy). The number of women with benign breast diseases (BBD) was 116 (67%). All recognizable chromosome lesion types were scored in the first in vitro division metaphases stained with azure-eosin. The mean total aberration frequency in the sample studied was 3.5±0.2 per 100 metaphases, the main contribution being made by the chromatid deletions, which is typical for a normal spontaneous aberration pattern. Based on the results of the cytogenetic analysis, the study population was subdivided into two groups. Group A (128 women) included subjects who showed normal patterns of spontaneous chromosome aberrations. Abnormal patterns, including the aberration frequencies significantly (at p<0.05) exceeding the mean group value and/or the presence
of chromosome type exchange aberrations, were found in 45 women (group B).
Statistical hypotheses on the possible correlations between the cytogenetic anomalies, BBD, level of the territory radiation contamination, and the absorbed thyroid dose were tested. The proportion of women with BBD was approximately the same in groups A and B (68 and 64%, respectively; p=0.665), which did not allow us to state that abnormal chromosome patterns can be used as diagnosis markers.
The data obtained showed some positive trends between the cytogenetic anomalies, breast disorders, level of the territory contamination and the thyroid dose. In addition, it is interesting to note that the inclusion of the body mass index (BMI) into the data analysis showed that, both in women with cytogenetic anomalies (group B) and among the women with BBD, this index was essentially lower than in the respective comparison groups. The BMI differences could not be explained by the age differences, since the latter were insignificant in all the cases (p>0.8).
A Flood Disaster Area Extraction Using KOMPSAT-1 EOC Satellite Image Data
Authors: Jun Jung Nam , Seo Doo Chun , Lim Hyo Suk
Published: March 2009

The main objective of this study is to observe and extract relevant geographical information of areas afflicted with floods using KOMPSAT-1 EOC image data. The satellite images taken on September 2, 2002 of the downstream of the river of Nakdong in the province of South Gyeongsang afflicted with floods at that time are used for the purpose of demonstration. To extract information which is the boundary lines and area in flood disaster area should be made to the ortho-image with characteristic of map. The generation of ortho-images involve sensor modeling using control points and DEM to restore a geometric relation of a satellite, its images and ground of which images are provided by the satellite. Candidate areas for edge extraction are selected based on ortho-corrected images through edge preserving smoothing method, high-pass filter and Prewitt operator. Based on the generated candidate areas, edges are extracted by use of edge extracting algorithm. The resultant extracted edges enable the overall status of flooded areas to be promptly grasped. This paper demonstrates such scope of utilization of satellite data for investigation and recovery of areas damaged by natural disasters.
The Comparison between Calculation Methods on the Solar Position in the Chiljeongsan Naepion and Chiljeongsan Oepion
Authors: Ahn Y.S. , Lee E.H.
Published: March 2009

The Chiljeongsan Naepion (七政算內篇) and the Chiljeongsan Oepion (七政算外篇), landmark achievements in the field of astronomical calendars in Korea, were published in the 26th year (1444 A.D.) of the reign of King Sejong (世宗, 1418-1450 A.D.) of the Choseon(朝鮮) dynasty, firmly establishing the calendar making system of Choseon. The Chiljeongsan Naepion adopts the conventions of the Shoushi calendar (授時曆) of the Yuan (元) dynasty (1280-1367 A.D.) of China, but also consults the Datong calendar (大統曆) and the modified Datong-li Tongkue (大統曆通軌), published during the Ming(明) dynasty (1368-1643 A.D.) of China. Furthermore, the Chiljeongsan Naepion corrects errors in the referred Chinese calendars and adds calculations of sunrise and sunset at the latitude of Seoul. On the other hand, the Chiljeongsan Oepion adopts the conventions of the Huihui calendar (回回曆) of Arabia translated and edited by the Arabian astronomer Mashayihei (馬沙亦黑) [1] in China. The Huihui calendar uses an Islamic theory of epicycles for its treatment of lunar and planetary motions. This means that aspects of the Ptolemaic system had been introduced into the Korean astronomy in the 15th century The calendar of the Choseon dynasty was made by the method of Chiljeongsan Naepion, but the calculations of solar and lunar eclipses and five planet’s positions are compared to those of the Chiljeongsan Oepion. In this paper, we discussed mainly the differences of the calculation methods of the solar positions in both calendars.
Integration of Landsat ETM+ and Radarsat SAR Data for Land Cover Classification
Authors: Kim Sun Hwa , Lee Kyu Sung
Published: March 2009

This study aims to analyze the synergic effect of integrating two distinctive satellite
remote sensor data (optical and microwave imagery) for land cover classification. The study area covers diverse land cover types in the Western coastal region of the Korean peninsula. Eleven land cover types were classified using several datasets of combined Landsat ETM+ and Radarsat synthetic aperture radar (SAR) data as well as only a single dataset of either ETM+ or SAR data alone. Furthermore, we introduced a texture image that was derived from the SAR data. The
synergic effect of these combined datasets was evident by both image interpretation and computerassisted classification. The overall classification accuracy of the combined datasets was improved to 74.60% as compared to the 69.35% accuracy of using ETM+ data alone.
High-Resolution Spectroscopy of 15 Metal-Poor Stars
Authors: Jeong Hyun Jin , Lee Jae Woo , Kim Sug Whan , Kang A Ram
Published: March 2009

We present high-resolution chemical abundance results of 15 metal-poor dwarf stars in the solar neighborhood. Our metallicity measurements are in a good agreement with previous estimates. The stars under investigation have metallicities ranging from -1.6 to -2.8 with the mean value of [Fe/H] = -2.28. The mean values of elemental abundances are [O/Fe] = 0.73, [Na/Fe] = -0.16, [Ca/Fe] = 0.28, and [Ti/Fe] = 0.60. Our results are found to be consistent with those of giant metal-poor stars.
Preparation of Maghemite Nanoparticles for Clinical Applications
Authors: Woo Kyoungja , Lee Ho Jin
Published: March 2009

The synthesis of nearly monodisperse, roughly spherical, and non-aggregated maghemite (g-Fe2O3) nanoparticles (average diameter = 5.5 nm, standard deviation = 0.7 nm over 100 particles) is reported. We utilized a sol-gel reaction of common ferric salt in reverse micelles and then, crystallization of the gel particles by reflux. The nanoparticles show superparamagnetic behavior and are expected to be useful for clinical applications.
Polymer-Stabilized Co Nanocrystals
Authors: Shin Eun Young , Fang Jiye , O'Connor Charles J. , Golub Vladimir , Wang Cuiying , Jun Moon Jin
Published: March 2009

Polymer-coated cobalt nanocrystals were prepared in a polar solvent at high temperature through an organometallic thermal-decomposition route in the presence of poly (N-viny-2- pyrrolidone) as a protective polymer. The as-synthesized PVP-coated cobalt nanocrystals were 20 to 80 nm cubic/hexagonal shapes. HCP was further determined as a main phase in these samples. For comparison purposes, we have also prepared PVP-cobalt nanocrystals using the seed-mediated thermal decomposition method. It revealed that PVP plays a significant role in the synthesis of cubicstructured cobalt nanocrystals. It was also noted that the formation of Co nanocrystals and their magnetic properties were dependent not only on the PVP component but also in the synthetic route. The saturation magnetization (MS) determined from the seed-mediated sample is lower than that of the conventional sample. The coercivity of the former (610 Oe at 5 K), however, is double that of
latter (300 Oe at 5 K), indicating that coercivity strongly depends on the crystallinity of the cobalt.
HOMO-LUMO Interaction between Diene and Dienophile with an Electron-Withdrawing Group
Authors: Oh Teresa , Lee Kwang Man , Kim Kyung Sik , Oh Sung Bo , Kim Won Hyung , Choi Chi Kyu
Published: March 2009

Recently, the carbon-centered organic system with C-H hydrogen bonds is being examined and reported with particular focus on its chemical shifts. These properties are traditionally associated with the red shifted hydrogen bond due to the weak interaction of C-H hydrogen bonds. In a few cases, however, the strengthening of the C-H bond is characterized by the blue shift. In this study, organic-inorganic hybrid silica and fluorinated amorphous carbon films have been deposited on a
p-type Si (100) substrate by inductively coupled plasma chemical vapor deposition. The reason for the chemical shift in the low dielectric constant materials with C-H hydrogen bonds was researched on, and the effect of the meso-structure of the films by the inverse electron demand Diels-Alder reaction of the C=C and C=O double bond was also studied.
Indentation Creep in Zirconia Ceramics under Variable Loads
Authors: Ren X.J. , Hooper R.M. , Henshall J.L.
Published: March 2009

Time dependent deformation at room and elevated temperature is a significant property of zirconia ceramics and has a direct influence on their use. An understanding of this time dependent behaviour is therefore important in predicting the service life of a component. In this work, the indentation creep behaviour of two typical zirconia ceramics ¾ ceria stabilised polycrystalline tetragonal (Ce-TZP) and yttria (6%) stabilized polycrystalline cubic zirconia, YCPZ, have been investigated from room temperature to 600 °C. Indentation creep tests with various loads yielded identical creep rate, which indicates that indentation size effect has no significant effect on the indentation creep of zirconia ceramics. Tests with variable loads, using a spring loaded apparatus, exhibited comparable indentation creep rates to that under constant loading.
Rheological Behaviors of Alumina Aqueous Suspensions
Authors: Wang Tie Chao , Yang Jin Long , Ma Li Guo , Huang Yong
Published: March 2009

Rheological behaviors of alumina aqueous suspension were investigated, and some methods to modify the rheological behaviors of the suspensions were studied. It was found that there is a critical solid volume fraction for alumina aqueous suspensions. When the volume fraction reaches or exceeds the critical value the suspensions show shear thinning behaviors all along, while above which the rheological behaviors of alumina suspensions change from shear thinning to shear thickening.
Effects of PLS on Green State Joining ZrO2/Al2O3 Ceramics
Authors: Wei Yan Qiu , Liu Jia Chen , Zhang Xin Xin , Zhao Yu Hong
Published: March 2009

A new kind of polymer/layered silicate (PLS) nanocomposites-containing slurry was used to join green bodies of ZrO2 (8YSZ) and 95Al2O3 ceramics, without applied pressure. After sintering, a fine joint could be obtained without obvious cracks, pores and other defects, and the average flexural strength of the joints was comparable to that of the 95Al2O3 matrix. Effects of PLS on joining
process were analyzed and the results showed suitability of PLS-containing slurry for green state joining ZrO2 to Al2O3 ceramics.
Effect of Microstructure on the Wear Resistance of Alumina Dispersed Y2O3-ZrO2 Ceramics
Authors: Liang Xiao Ping , Yang Zheng Fang , Yuan Q.M. , Jin Zheng Guo
Published: March 2009

The effect of microstructure on the wear resistance of two Al2O3 dispersed in ZrO2 matrix (ADZ) ceramics was investigated, Al2O3 dispersed in commercially co-precipitated 3mol% Y2O3-doped tetragonal zirconia polycrystal (CYADZ) and Al2O3 dispersed in mixed 3mol% Y2O3-doped tetragonal zirconia polycrystal (MYADZ). These materials were used as a pin sliding against a plate of polyurethane rubber (UR) in the presence of aqueous NaOH solution containing
SiO2 as the abrasive medium at a sliding speed of 0.15m/s and a normal load of 100N. The results indicated that the CYADZ specimen had uniform microstructure and fine grain size, which accounted for its better abrasive wear-resistance than that of the MYADZ specimen with non-uniform microstructure and largely different grain sizes due to inhomogeneous distribution of Y2O3. The hardness and toughness of two ADZ specimens were close, but strength of the MYADZ specimen
was lower than that of the CYADZ specimen, which indicated the defect was serious in the MYADZspecimen. The CYADZ specimen was characterized by plastic deformation and micro-ploughing, which the MYADZ specimen dominated by micro- cracking and brittle fracture.
Characteristics of Machinable LaPO4/Al2O3 Composites
Authors: Min Jiang , Liu Jia Chen , Du Hai Yan , Liu Yi Rong , Cao Zhi Jun
Published: March 2009

Some useful characteristics, including strength, toughness, damage of machining, and propagation pattern of indentation cracks, were studied based on machinable 30 wt%LaPO4/ Al2O3 composites. Corresponding characteristics for Al2O3 ceramic were also concerned for comparing. The results supplied some elementary information for both use and further study of LaPO4/ Al2O3
composites.
Preparation of CIM Feedstock of Al2O3-SiC Nanocomposite
Authors: Luting Yan , Wenjie Si , Tao Xiong , Hezhuo Miao
Published: March 2009

The ceramic injection molding feedstock of Al2O3-SiC nanocomposite were prepared and studied in detail. Three ways of surface modification including surfactant pre-coating, surface emulsion polymerization and surface low temperature plasma polymerization were used to modify the surface of SiC powders in order to reduce the agglomeration, improve the dispersion and the compatibility with organic media. CIM feedstock with different SiC content and solid loading were
prepared through mixing surface modified SiC powders with Al2O3 powders and organic binders. The effect of three ways of surface modification on the viscosity of CIM feedstock were studied and the way of surface emulsion polymerization developed the best action in increasing dispersion, reducing viscosity and improving the solid loading of CIM feedstock.
Pressureless Sintering the Al2O3/SiC Nanocomposites in Deoxidized Atmosphere
Authors: Peng Zhen Zhen , Cai Shu , Wang Yan Wei , Wu Hou Zheng
Published: March 2009

Many significant improvements have been shown in mechanical properties of ceramic nanocomposites with ceramic matrix being dispersed with second sub-micro sized (or nano-sized) phase. This study designed and fabricated Al2O3/SiC nanocomposites with a raw material used for 85% alumina as matrix and
SiC grits in submicro-scale as dispersion phase via a controlled pressureless sintering in air. With coarse SiC powder as bed powder, both C and SiC powder making deoxidized atmosphere, 85Al2O3/SiC nanocomposites with different SiC contents were densified by pressureless sintering at low temperature. Fracture surface investigation indicated that dense nanocomposites with small grain size were produced. General material properties and microstructure were measured and characterized. The results showed that composites sintered in deoxidized atmosphere had better mechanical properties than those sintered in flowing argon.
Al2O3 Multiphase Ceramics Coatings Sprayed by SHS-RFS Based on the Cladding Powders
Authors: Wang Jian Jiang , Du Xin Kang , Liu Hong Wei , Yan Jun
Published: March 2009

Based on SHS reactive flame spray technology, Al2O3 multiphase ceramics coatings were produced. Chemical copper-plating technology was used to produce the Al-CuO powders of copper cladding, which became individual SHS reactive units respectively. The phenomena and principles of the SHS reactive flame spray of the Al-CuO powders of copper cladding forming Al2O3 multiphase ceramics
coatings were investigated. It was found that copper cladding of Al-CuO powders were necessary for the SHS reaction during the spray process. The better the cladding was, the more sufficient the SHS reaction, and the higher the transformation rate was. The Cu and Al2O3 fine molten drops produced by the SHS
reaction bumped the substrate and flatted to form layer-shaped Al2O3-based multiphase ceramics coatings. The binding strength between the coating and substrate was as high as 19.8MPa, and the micro-hardness of the coatings was Hv712. The overall properties of the coatings were better than those of the ceramics
coatings sprayed by the traditional flame spray.
Preparation of High Capacity Thin-Wall Rutile Tube for Ozone Generator by Colloidal Injection Moulding of Ceramics
Authors: Ma Tian , Huang Yong , Yang Jin Long , Zhang Li Ming , Zhao L.
Published: March 2009

Colloidal injection moulding of ceramics (CIMC), an innovative technique combining the advantages of conventional injection moulding and colloidal forming process, is applied to prepare thin-wall rutile tube for high capacity ozone generator. The forming process is studied detailed and the processing parameter of forming, drying and sintering schedule is determined in this research. The wall thickness of the sintered tube is 1.5~2mm and its inner diameter is about 26 mm, length is about
300 mm. The electric properties of the tube are also measured under different conditions. The above-mentioned tube is applied in ozone generator and the yield of ozone is about 55mg·L-1.
Production of Si3N4 Whiskers in Solid Mixtures through Vapor-Solid Mechanism Using 2MgO 2Al2O3 5SiO2 as Sintering Additives
Authors: Guo Wenli , Xu Ting Xian , Zou Qiang , Ge Chang Chun
Published: March 2009

The production of silicon nitride whiskers in solid mixtures under nitrogen-containing
atmospheres was investigated. Green bodies made of micron and nano silicon nitride powders with 2MgO×2Al2O3×5SiO2 as sintering additive were sintered at 1500~1560oC in flowing nitrogen-containing atmospheres. Resultantly whisker-like products were formed on the cold side of the graphite boat. X-ray diffraction analysis indicated that the formed whisker were α–Si3N4. The products were analyzed by transmission electron microscope. The morphologies of the resulting whisker were varied with sintering temperatures and atmospheres. Dislocation structures were observed on the edge of some whiskers. This suggested that the whisker growth proceeded through a vapor-solid (VS) mechanism. The mechanism of whiskers growth at different temperatures and atmospheres was discussed with a thermodynamic calculation based on a database software.