• Journal of Nutrition and Health
• /
• v.9 no.2
• /
• pp.68-86
• /
• 1976

The primary purpose of this study is to evaluate the correct nutritional status on pre-school children in Korea. Furthermore, it made an attempt to find and define nutrional problems, and assist in establishment on their nutritional improvement plan. For this, food intake and health condition (physical, clinical, biochemical and parasitological) survey on 109 Pre-school children in both sexes, randomly selected from Yang-Gu area in Gang-Won province and Rea-ju area in Kyong-gy Province, were conducted by means of three-day records, during the two periods of Spring and Fall season in 1975. The results obtained are summerized as follows: 1. The food intake; Average food intake of the subjects per day were $508{\sim}647g$ ($83{\sim}91%$ in vegetable foods and $5.5{\sim}11.7%$ in animal foods) in Yang-gu area, and $587{\sim}698g$ ($88{\sim}89%$ in vegetable foods and $6.3{\sim}7.6%$ in animal foods) in Rea-ju area. 2. The intake of energy and nutrients; a) Calory intake. Average energy intake of subjects per day in Yang-gu area$(1120{\sim}1415kcal)$ were all lower than the Korean Recommended Dietary Allowances (RDA) in either Spring and Fall survey, whereas the subjects in Rea-ju area were lower intake $(1213{\sim}1418kcal)$ than the RDA in the Spring but higher intake$(1516{\sim}1755kcal)$ than the RDA in the Fall, and the average intake were similar level with that of RDA. b) Protein intake. Average protein intake of the subjects per day in Yang-gu area $(33{\sim}43g)$ girl subjects in Rea-ju area $(35{\sim}39g)$ were lower than the RDA in either Spring and Fall survey, whereas the boy subjects in Rea-ju area$(36{\sim}38g)$ were lower in Spring and higher $(49{\sim}57g)$ in the Fall than that of the RDA, but the average $(43{\sim}47g)$ were similar level with the RDA. The protein intake from animal sources in all subjects were much lower $(5.5{\sim}11.7\;of\;total\;protein)$ than the RDA. c) Fat intake. Average fat intake were very lower in all subjects of both area $(14{\sim}24g\;in\;Yang-gu,\;10{\sim}12g\;in\;Rea-ju)$ than that of RDA which is recommended $12{\sim}14%$ of total energy to be supplied from fat. d) Calcium intake. Average calcium intake were very low in all subjects of both area $(264{\sim}355mg\;in\;Yang-gu\;and\;283{\sim}429mg\;in\;Rea-ju)$, especially, these in Spring were about a half level of the RDA, and it was much increased in the Fall due to increased intake of milk, but it was still not enough than the RDA. e) Vitamin A intake. Average intake of V.A ($703{\sim}1465\;IU$ in Ynag-gu and $750{\sim}1521\;IU$ in Rea-ju) were also lower than the RDA, moreover their V-A sources were mainly vegetable, so that the V-A supply might be critical one for the subjected. f) Riboflavin intake. Average riboflavin intake on all subjects in both area except boys in Rea-ju area in Fall, were very lower than the RDA. 3. The physical status; a) Average weight and height of boys aged 4 and 5 in Yang-gu area and girls of aged 5 in Rea-ju area were lower than those of Korean Standard of 1967 report, but those by age of girls in Yang-gu area and boys in Rea-ju area were a little heigher than the Korean Standard. It is, hower, present Korean standard of physical status might be somehow heigher than the 1967, since the socio-economical situation has been much improved during past a decade. So that, if one considered on this sense, the physical status of the subjects on this survey might be somehow lower than those of present Korean standard. b) Average upper arm circumference in both area were no difference each other, and their mean values of age 4, 5 and 6 in boy and girl were 15.6, 16.5, 16.4 and 15.5, 16.5, 16.4cm respectively. c) Average chest girth of boys were similar to those of Korean standard whereas the girls were smaller than the Korea standard. The average head circumference also showed similar tendency with the chest girth. 4. The clinical findings; The most popular clinical signs were angular stomatitis and dental caries, and boys had more heigher incidence then the girls. 5. The biochemical findings; a) Hemoglobin and anemia Average Hb value of boys and girls were 11.4 and 10.9g per 100 ml of blood respectively. The incidence of anemia (Hb value below 11 g/100 ml, by WHO) was increased by age, and girls had more heigher incidence than the boy (34% : 48%). The incidence of anemia in age of 4,5, and 6 in boys and girls were 28%, 41% 34%, and 33%, 50%, 49% respectively. The degree of the anemia was not severe, and the anemia of there subjects may be caused mainly low intake of better quality protein and low iron intake as well. b) Hematocrit. Average Ht value of whole subject were $39.9{\sim}41.6%$. c) Blood plasma protein. Average blood plasma protein contents of whole subjects were $6.6{\sim}7.4gm$ per 100 ml. The incidence of deficient range (<6.0g%, by ICNND) was only one girl of age 4 in yang Gu area. 6. Parasitological findgs; The most popular parasitism were asicris lumbicoides and trichocephalus trichiura, and about 2/3 of the whole subjects were suffering one or more of these parasitism.

• Journal of Korea Technology Innovation Society
• /
• v.10 no.1
• /
• pp.73-97
• /
• 2007

R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.17 no.1
• /
• pp.3642-3654
• /
• 1975

The purpose of this thesis is to derive a unit hydrograph which may be applied to the ungaged watershed area from the relations between directly measurable unitgraph properties such as peak discharge(qp), time to peak discharge (Tp), and lag time (Lg) and watershed characteristics such as river length(L) from the given station to the upstream limits of the watershed area in km, river length from station to centroid of gravity of the watershed area in km (Lca), and main stream slope in meter per km (S). Other procedure based on routing a time-area diagram through catchment storage named Instantaneous Unit Hydrograph(IUH). Dimensionless unitgraph also analysed in brief. The basic data (1969 to 1973) used in these studies are 9 recording level gages and rating curves, 41 rain gages and pluviographs, and 40 observed unitgraphs through the 9 sub watersheds in Nak Oong River basin. The results summarized in these studies are as follows; 1. Time in hour from start of rise to peak rate (Tp) generally occured at the position of 0.3Tb (time base of hydrograph) with some indication of higher values for larger watershed. The base flow is comparelatively higher than the other small watershed area. 2. Te losses from rainfall were divided into initial loss and continuing loss. Initial loss may be defined as that portion of storm rainfall which is intercepted by vegetation, held in deppression storage or infiltrated at a high rate early in the storm and continuing loss is defined as the loss which continues at a constant rate throughout the duration of the storm after the initial loss has been satisfied. Tis continuing loss approximates the nearly constant rate of infiltration (${\Phi}$-index method). The loss rate from this analysis was estimated 50 Per cent to the rainfall excess approximately during the surface runoff occured. 3. Stream slope seems approximate, as is usual, to consider the mainstreamonly, not giving any specific consideration to tributary. It is desirable to develop a single measure of slope that is representative of the who1e stream. The mean slope of channel increment in 1 meter per 200 meters and 1 meter per 1400 meters were defined at Gazang and Jindong respectively. It is considered that the slopes are low slightly in the light of other river studies. Flood concentration rate might slightly be low in the Nak Dong river basin. 4. It found that the watershed lag (Lg, hrs) could be expressed by Lg=0.253 (L.Lca)0.4171 The product L.Lca is a measure of the size and shape of the watershed. For the logarithms, the correlation coefficient for Lg was 0.97 which defined that Lg is closely related with the watershed characteristics, L and Lca. 5. Expression for basin might be expected to take form containing theslope as {{{{ { L}_{g }=0.545 {( { L. { L}_{ca } } over { SQRT {s} } ) }^{0.346 } }}}} For the logarithms, the correlation coefficient for Lg was 0.97 which defined that Lg is closely related with the basin characteristics too. It should be needed to take care of analysis which relating to the mean slopes 6. Peak discharge per unit area of unitgraph for standard duration tr, ㎥/sec/$\textrm{km}^2$, was given by qp=10-0.52-0.0184Lg with a indication of lower values for watershed contrary to the higher lag time. For the logarithms, the correlation coefficient qp was 0.998 which defined high sign ificance. The peak discharge of the unitgraph for an area could therefore be expected to take the from Qp=qp. A(㎥/sec). 7. Using the unitgraph parameter Lg, the base length of the unitgraph, in days, was adopted as {{{{ {T}_{b } =0.73+2.073( { { L}_{g } } over {24 } )}}}} with high significant correlation coefficient, 0.92. The constant of the above equation are fixed by the procedure used to separate base flow from direct runoff. 8. The width W75 of the unitgraph at discharge equal to 75 per cent of the peak discharge, in hours and the width W50 at discharge equal to 50 Per cent of the peak discharge in hours, can be estimated from {{{{ { W}_{75 }= { 1.61} over { { q}_{b } ^{1.05 } } }}}} and {{{{ { W}_{50 }= { 2.5} over { { q}_{b } ^{1.05 } } }}}} respectively. This provides supplementary guide for sketching the unitgraph. 9. Above equations define the three factors necessary to construct the unitgraph for duration tr. For the duration tR, the lag is LgR=Lg+0.2(tR-tr) and this modified lag, LgRis used in qp and Tb It the tr happens to be equal to or close to tR, further assume qpR=qp. 10. Triangular hydrograph is a dimensionless unitgraph prepared from the 40 unitgraphs. The equation is shown as {{{{ { q}_{p } = { K.A.Q} over { { T}_{p } } }}}} or {{{{ { q}_{p } = { 0.21A.Q} over { { T}_{p } } }}}} The constant 0.21 is defined to Nak Dong River basin. 11. The base length of the time-area diagram for the IUH routing is {{{{C=0.9 {( { L. { L}_{ca } } over { SQRT { s} } ) }^{1/3 } }}}}. Correlation coefficient for C was 0.983 which defined a high significance. The base length of the T-AD was set to equal the time from the midpoint of rain fall excess to the point of contraflexure. The constant K, derived in this studies is K=8.32+0.0213 {{{{ { L} over { SQRT { s} } }}}} with correlation coefficient, 0.964. 12. In the light of the results analysed in these studies, average errors in the peak discharge of the Synthetic unitgraph, Triangular unitgraph, and IUH were estimated as 2.2, 7.7 and 6.4 per cent respectively to the peak of observed average unitgraph. Each ordinate of the Synthetic unitgraph was approached closely to the observed one.

• Journal of Technology Innovation
• /
• v.5 no.2
• /
• pp.1-21
• /
• 1997

The objective of this paper is to think about what structural reforms of the Korean government S&T development management system might be. Korean society is currently experiencing a drastic socio-economic transformation. The results of this transformation should be reflected on the determining process of the directions and breadths of structural reforms of government S&T development management system. Because the government system design will be based on the premises of socio-economic conditions under which administrative activities perform and also this socio-economic changes can influence on changes of the premises of government management system design. Moreover, S&T development management system is a subsystem of government system so that the directions of structural reform of those subsystems should be considered in the broad framework changes in the development management system of the government. For the last forty years, the Korean government S&T development management system has been based on the premises including transformation from an agrarian society to an industrial society, authoritarianism and centrally controlled institutions, and exteremely small portions of private investments for science and thechonology R & D of the total. Recently, however, the premises of Korean government S&T development management system have rapidly changed. the characteristics of these changes are including tranformation from an industrial society to a knowledge and information intensive society, globalization, localization, and relatively large portion of private investments for science and technology R & C of the total. The basis of government reforms in Korea was the realization of the performances and values through the enhancement of national competitive capacity, attainment of lean government, decentralization and autonomy. However, the Korean government has attached a symbolic value of strategic organizations representing strong policy intentions of government for the science and technology based development. Most problems associated with the Korean government S&T development management system have grown worse during 1990s. Many people perceive that considerable part of this problem was generated because the government could not properly adapt itself to new administrative environment and the paradigm shift in its role. First of all, the Korean government S&T development management system as a whole failed to develop an integrated vision under which processes in formulating science and thechology development goals and developing consistent government plans concerning science and technology development are guided. Second, most of the local governments have little organizational capacity and manpowers to handle localized activities to promote science and technology in their regions. Third, the measure to coordinate and set priorities to invest resources for the development of science and technology was not effective. Fourth, the Most has been losing its reputation as the symbol of ideological commitment of the top policy maker to promote science and technology. Various ideas to reform government S&T development management system have been suggested recently. Most frequently cited ideas are as follow : (ⅰ)strengthen the functions of MoST by supplementing the strong incentive and regulatory measures; (ⅱ)create a new Ministry of Education, Science & Technology and Research by merging the Ministry of Education and the MoST; (ⅲ)create a new Ministry of Science & Technology and Industry ; and(ⅳ)create a National Science and Technology Policy Council under the chairmanship of the President. Four alternatives suggested have been widely discussed among the interested parties and they each have merits as well as weaknesses. The first alternative could be seen as an alternative which cannot resolve current conflicts among various ministries concerning priority setting and resource allocation. However, this alternatives can be seen as a way of showing the top policymaker's strong intention to emphasize science and technology based development. Second alternative is giving a strategic to emphasize on the training and supplying qualified manpower to meet knowledge and information intensive future society. This alternative is considered to be consistent with the new administrative paradigm emphasizing lean government and decentralization. However, opponents are worrying about the linkages and cooperative research between university and industry could be weakening. The third alternative has been adopted mostly in nations which have strong basic science research but weak industrial innovation traditions. Main weakness of this alternative for Korea is that Korean science and technology development system has no strong basic science and technology research traditions. The fourth alternative is consistent with new administrative paradigms and government reform bases. However, opponents to this alternative are worried that the intensive development of science and technology because of Korea's low potential research capabilities in science and technology development. Considerning the present Korean socio-economic situation which demands highly qualified human resources and development strategies which emphasizes the accumulations of knowledge-based stocks, I would like to suggest the route of creating a new Ministry of Education, Science & Technology and Research by intergrating education administration functions and science & technology development function into one ministry.

• Journal of Embryo Transfer
• /
• v.19 no.2
• /
• pp.173-183
• /
• 2004

This study was carried out to examine the effects of epidermal growth factor (EGF) and the number of cumulus-oocyte complexes (COCs) on in vitro maturation (IVM) of porcine immature oocytes, and on subsequent in vitro fertilization (IVF) and development (IVD). COCs were collected from antral follicles of porcine ovaries collected from abattoir, and were maturated in modified NCSU-23 (mNCSU-23) with 10% pFF, 0.6 mM cysteine, 50 ${\mu}mM{\beta}-mercaptoethanol$, 1 mM dbcAMP, 10 IU/mL PMSG and 10 IU/mL hCG, which was supplemented with or without 10 ng/mL EGF and into which 50 or 15 COCs per droplet was put. Oocytes matured in vitro, were fertilized in vitro in modified Tris-buffered medium (mTBM) with the final motile sperm concentration of 1${\times}$105 sperm/mL, and subsequently putative embryos were developed in vitro in NCSU- 23. The results are as follows. 1.In the result of IVM, 10 ng/mL EGF supplement duplicated the percentage of C4 group of COCs(41% vs 81%). But the rate of germinal vesicle breakdown (GVBD) and of nuclear maturation were not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, and there was not a significant interaction between the two factors, either. 2. In the result of IVF, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, or was not a significant interaction between the two factors, in the rate of sperm penetration, in the percentage of oocytes with male pronucleus (MPN), and in the rate of polyspermy. 3. In the result of IVD, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet in the percentage of cleaved oocytes. There was not significantly different between the number of COCs per culture droplet, but between control and EGF supplemented (p<0.01) in the percentage of blastocysts, the number of inner cell mass (ICM), trophectoderm (TC) and total cells. There was no significant interaction between the two factors anywhere. These results suggested that 10 ng/mL EGF supplement into mNCSU-23 for IVM was effective in the production of more as well as better blastocysts during IVD through increasing the number of cells in those.

• Investigative Magnetic Resonance Imaging
• /
• v.5 no.1
• /
• pp.57-65
• /
• 2001

Purpose : $T_2$-weighted half courier Echo Planar Imaging (T2HEPI) method is proposed to reduce measurement time of existing EPI by a factor of 2. In addition, high $T_2$ contrast is obtained for clinical applications. High resolution single-shot EPI images with $T_2$ contrast are obtained with $128{\times}128$ matrix size by the proposed method. Materials and methods : In order to reduce measurement time in EPI, half courier space is measured, and rest of half courier data is obtained by conjugate symmetric filling. Thus high resolution single shot EPI image with $128{\times}128$ matrix size is obtained with 64 echoes. By the arrangement of phase encoding gradients, high $T_2$ weighted images are obtained. The acquired data in k-space are shifted if there exists residual gradient field due to eddy current along phase encoding gradient, which results in a serious problem in the reconstructed image. The residual field is estimated by the correlation coefficient between the echo signal for dc and the corresponding reference data acquired during the pre-scan. Once the residual gradient field is properly estimated, it can be removed by the adjustment of initial phase encoding gradient field between $70^{\circ}$ and $180^{\circ}$ rf pulses. Results : The suggested T2EPl is implemented in a 1.0 Tela whole body MRI system. Experiments are done with the effective echo times of 72ms and 96ms with single shot acquisitions. High resolution($128{\times}128$) volunteer head images with high $T_2$ contrast are obtained in a single scan by the proposed method. Conclusion : Using the half courier technique, higher resolution EPI images are obtained with matrix size of $128{\times}128$ in a single scan. Furthermore $T_2$ contrast is controlled by the effective echo time. Since the suggested method can be implemented by software alone (pulse sequence and corresponding tuning and reconstruction algorithms) without addition of special hardware, it can be widely used in existing MRI systems.

• Journal of Magnetics
• /
• v.20 no.4
• /
• pp.381-386
• /
• 2015

The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2000.04a
• /
• pp.9-10
• /
• 2000

An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.

• Reproductive and Developmental Biology
• /
• v.31 no.3
• /
• pp.161-167
• /
• 2007

In this study, we constructed and tested retrovirus vectors designed to express the human thrombopoietin gene under the control of the tetracycline-inducible promoters. To increase the hTPO gene expression at him-on state, WPRE sequence was also introduced into retrovirus vector at downstream region of either the hTPO gene or the sequence encoding reverse tetracycline-controlled transactivator (rtTA). Primary culture cells (PFF, porcine fetal fibroblast; CEF, chicken embryonic fibroblast) infected with the recombinant retrovirus were cultured in the medium supplemented with or without doxycycline for 48hr, and induction efficiency was measured by comparing the hTPO gene expression level using RT-PCR, western blot and ELISA. Higher hPTO expression and tighter expression control were observed from the vector in which the WPRE sequence was placed at downstream of the hTPO (in CEF) or rtTA(in PFF) gene. This resulting tetracycline inducible vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals.

• Investigative Magnetic Resonance Imaging
• /
• v.2 no.1
• /
• pp.96-103
• /
• 1998

Purpose : To assess the clinical utility of turbo contrast-enhanced magnetic resonance angiography(CE MRA) in the evaluation of the aortic arch and its major branches and to compare the image quality of CE MRA among different coils used. Materials and Methods : Turbo three-phase dynamic CE MRA encompassing aortic arch and its major branches was prospectively performed after manual bolus IV injection of contrast material in 29 patients with suspected cerebrovascular diseases at 1.0T MR unit. the raw data were obtained with 3-D FISH sequence (TR 5.4ms, TE 2.3ms, flip angle 30, slab thickness 80nm, effective slice thickness 4.0mm, matrix size $100{\times}256$, FOV 280mm). Total data acquisition time was 4. to 60 seconds. We subjectively evaluated the imge quality with three-rating scheme : "good" for unequivocal normal finding, "fair" for relatively satisfactory quality to diagnose 'normal' despite intravascular low signal, and "poor" for equivocal diagnosis or non-visualization of the origin or segment of the vessels due to low signal or artifacts which needs catheter angiography. At the level of the carotid bifurcation, it was compared with conventional 2D-TOF MRA image. Overall image quality was also compared visually and quantitatively by measuring signal-to-noise ratios (SNRs) of the ascending aorta, the innominate artery and both common carotid arteries among the three different coils used(CP body array(n=12), CP neck array(n=9), and head-and-neck(n=8). Results : Demonstration of the aortic arch and its major branches was rated as "good" in 55% (16/29) and "fair" in 34%(10/29). At the level of the carotid bifurcation, image quality of turbo CE MRA was same as or better than conventional 2D-TOF MRA in 65% (17/26). Overall image quality and SNR were significantlygreater with CP body array coil than with CP neck array or head-and-neck coil. Conclusions : Turbo CE MRA can be used as a screening exam in the evaluation of the major branches of the aortic arch from their origin to the skull base. Overall imagequality appears to be better with CP body array coil than with CP neck array coil or head-and-neck coil.