• Title/Summary/Keyword: Serial Properties

Search Result 107, Processing Time 0.033 seconds

MODIFICATION OF METAL MATERIALS BY HIGH TEMPERATURE PULSED PLASMA FLUXES IRRADIATION

  • Vladimir L. Yakushin;Boris A. Kalin;Serguei S. Tserevitionov
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2000.05a
    • /
    • pp.1-1
    • /
    • 2000
  • The results of the modification of metal materials treated by high temperature pulst:d plasma fluxes (HTlPPF) with a specific power of incident flux changing in the $(3...100)10^5{]\;}W/cm^2$ range and a pulse duration lying from 15 to $50{\;}\mu\textrm{s}$ have been presented. The results of HTPPF action were studied on the stainless steels of 18Cr-l0Ni, 16Cr- 15Ni, 13Cr-2Mo types; on the structural carbon steels of (13...35)Cr, St. 3, St. 20, St. 45 types; on the tool steels of U8, 65G, ShHI5 types, and others; on nickel and high nickel alloy of 20Cr-45Ni type; on zirconium- and vanadium-base alloys and other materials. The microstructure and properties (mechanical, tribological, erosion, and other properties) of modified materials and surface alloying of metals exposed to HTPPF action have been investigated. It was found that the modification of materials by HTPPF resulted in a simultaneous increase of several properties of the treated articles: microhardness of the surface and layers of 40...60 $\mu\textrm{m}$ in depth, tribological characteristics (friction coefficient, wear resistance), mechanical properties ({\sigma_y}, {\;}{\sigma_{0.2}}.{\;}{\sigma_r}) on retention of the initial plasticity ($\delta$), corrosion resistance, radistanation erosion under ion irradiation, and others. The determining factor of the changes observed is the structural-phase modification of the near-surface layers, in particular, the formation of the fine cellular structure in the near-surface layers at a depth of $20{\;}{\mu\textrm{m}}$ with dimension of cells changing in the range from 0.1 to $1., 5{\;}\mu\textrm{m}$, depending on the kind of material, its preliminary treatment, and the parameters of plasma fluxes. The remits obtained have shown the possibility of purposeful surface alloying of metals exposed to HTPPF action over a depth up to 20...45 $\mu\textrm{m}$ and the concentration of alloying element (Ni, Cr, V) up to 20 wt.%. Possible industrial brunches for using the treatment have been also considered, as well as some results on modifying the serial industrial articles by HTPPF.

  • PDF

Spatial Variation Analysis of Soil Characteristics and Crop Growth across the Land-partitioned Boundary II. Spatial Variation of Soil Chemical Properties (구획경계선(區劃境界線)의 횡단면(橫斷面)에 따른 토양특성(土壤特性)과 작물생육(作物生育)에 관한 공간변이성(空間變異性) 분석연구 II. 토양(土壤) 화학성(化學性)의 공간변이성(空間變異性))

  • Park, Moo-Eon;Yoo, Sun-Ho
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.22 no.4
    • /
    • pp.257-264
    • /
    • 1989
  • In order to study spatial variability of soil chemical properties across the land-partitioned boundary on Hwadong silt clay loam soil (Fine clayey, mixed, mesic family of Aquic Hapludalfs) in the experimental fie ld of the wheat and Barley Research Institute in Suwon, all measured data were analyzed by means of kriging, fractile diagram, smooth frequency distribution, and autocorrelation. Sampling for soil chemical property analysis was made at 225 intersections of 15x 15 grid with 10m interval from three soil depths (0-10cm, 25-35cm, 50-60cm) in the seven patitioned fields. 1. The coefficient of variance (CV) of various chemical properties varied from 5.4 to 72.7%. Soil pH was classified into the low variation group with CV smaller than 10%, while the other chemical properties belonged to the medium variation group with C.V. between 10 and 100% 2. The approximate number of soil samples for the determination of various chemical properties with error smaller than 10% were two for pH, ten for CEC, 15 for exchangeable Ca, 32 for total nitrogen content, 39 for exchangeable Mg, 40 for exchangeable K, 61 for exchangeable Na, 82 for organic matter content, 212 for available phosphate,. 3. Smooth frequency distribution and fractile diagram showed that available phosphate was in log-normal distribution while others were in normal distribution. 4. Serial correlation analysis revaled that the soil chemical properties had spatial dependence between two nearest neighbouring grid points. Autocorrelation analysis of chemcial properties measured between the serial grid points in the direction of south to north following land-partitioned boundary showed that the zone of influence showing stationarity ranged from 20 to 50m. In the direction of east to west accross land-partitioned boundary, the autocorrelogram of many chemical properies showed peaks with the periodic interval of 30m, which were similar to the partitioned land width. This reveals that the land-partitioned boundary causes soil variability.

  • PDF

Studies on the Characters of Avian Infectious Bronchitis Virus Isolated in Korea. (국내 분리 닭 전염성 기관지염 바이러스 성상에 관한 연구)

  • 이청산;조우영;최윤식;김순재
    • Korean Journal of Veterinary Service
    • /
    • v.14 no.1
    • /
    • pp.27-40
    • /
    • 1991
  • In order to investigate the biological properties, pathogenicity and immune responses in artficially infected SPF chickens with Avian infectious bronchitis virus that was isolated from chickens showing IB like signs in southern region of Chung buk. Results obtained throuth the experiments are summarized as follows. 1. From 15 IB suspected cases, two strains of IB virus were isolated, one each from the tracheas and lungs. 2. Infectious bronchitis specific embryo lesions were observed after four serial passages of the isolates in chicken embryos. 3. The field isolates and M-41 strain of IB virus interfered with the replication of Newcastle disease virus in chicken embryos. 4. When specific pathogen free chickens, two week old, were inoculated with the IB virus isolates, clinical respiratory signs as dyspnea, coughing were observed. Airsacculitis was observed by necropsy. 5. AGP antibody positive rates of inoculated SPF chickens were highest on day 14 and lowest on day 36, while HI antibody responses were detected on day 14 in all Groups, the reinoculated Group was shown highest titers. 6. By Indirect immunofluorescence antibody assay of artificially infected SPF chickens, the viral antigens were detected in tissues of larynx, trachea and lung on the 4 th to 7 th days post inoculation.

  • PDF

Development of the Hybrid Type Robot Using a Pneumatic Actuator For Physical Therapy Of Ankylosis (관절 경직 환자의 물리 치료를 위한 공압 구동형 하이브리드 로봇 개발)

  • 최현석;최철우;한창수;한정수
    • Journal of Biomedical Engineering Research
    • /
    • v.24 no.2
    • /
    • pp.127-132
    • /
    • 2003
  • In this paper. the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantages of good compliance , high Payload-to-weight and payload-to-volume ratios. high speed and force capabilities. Using pneumatic actuators. which have low stiffness. the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into Positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory. the Pneumatic service robot is evaluated and verified.

Self-renewal and circulating capacities of metastatic hepatocarcinoma cells required for collaboration between TM4SF5 and CD44

  • Lee, Doohyung;Lee, Jung Weon
    • BMB Reports
    • /
    • v.48 no.3
    • /
    • pp.127-128
    • /
    • 2015
  • Tumor metastasis involves circulating and tumor-initiating capacities of metastatic cancer cells. Hepatic TM4SF5 promotes EMT for malignant growth and migration. Hepatocellular carcinoma (HCC) biomarkers remain unexplored for metastatic potential throughout metastasis. Here, novel TM4SF5/CD44 interaction-mediated self-renewal and circulating tumor cell (CTC) capacities were mechanistically explored. TM4SF5-dependent sphere growth was correlated with $CD133^+$, $CD24^-$, ALDH activity, and a physical association between CD44 and TM4SF5. The TM4SF5/CD44 interaction activated c-Src/STAT3/ Twist1/ B mi1 signaling for spheroid formation, while disturbing the interaction, expression, or activity of any component in this signaling pathway inhibited spheroid formation. In serial xenografts of less than 5,000 cells/injection, TM4SF5-positive tumors exhibited locally-increased CD44 expression, suggesting tumor cell differentiation. TM4SF5-positive cells were identified circulating in blood 4 to 6 weeks after orthotopic liver-injection. Anti-TM4SF reagents blocked their metastasis to distal intestinal organs. Altogether, our results provide evidence that TM4SF5 promotes self-renewal and CTC properties supported by $CD133^+/TM4SF5^+/CD44^+^{(TM4SF5-bound)}/ALDH^+/CD24^-$ markers during HCC metastasis.

A study on the effect of $TiO_2$ to the characterization of PTC thermister (PTC서미스터의 특성에 미치는 $TiO_2$의 영향에 관한 연구)

  • 신태현;김영조;이기택
    • Electrical & Electronic Materials
    • /
    • v.8 no.1
    • /
    • pp.83-89
    • /
    • 1995
  • In this paper, the specimens-($Ba_{0.997}$ L $a_{0.003}$)Ti $O_{3}$ + xTi $O_{2}$, x=0.005, 0.01, 0.02, 0.03[mol]- were fabricated by a solid-state reaction method which is easy in microstructure control and good in mass production. Their crystalline structures and microstructures were analysed, and electrical properties were investigated. The perovskite-crystalline structure is confirmed by XRD, and it is exhibited by SEM that the grain grows with an addition of Ti $O_{2}$. Resistivity decreases with increasing sinteiing temperature, and the specimen of ($Ba_{0.997}$ L $a_{0.003}$)Ti $O_{3}$ + 0.02Ti $O_{2}$ sintered at 1350.deg. C shows the best PTC effects. The complex impedance plots exhibit the serial equivalent circuit of ( $R_{gb}$ / $C_{gb}$ ) and $R_{g}$ it is realized that PTC effect is attributed to the resistivity of grain boundary.ary.y.

  • PDF

Operating Properties of Resistive Superconducting fault Current Limiters with Various Pattern Shapes

  • Park, Hyo-Sang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.12S
    • /
    • pp.1286-1291
    • /
    • 2003
  • Quench behavior of resistive superconducting fault current limiters (SFCLS) with various pattern shapes was investigated. The pattern shapes employed were meander, bi-spiral, and spital shapes of identical line width, gap and margin. SFCLS were fabricated from YBCO thin films grown on two-inch diameter Al$_2$O$_3$ substrates under the same conditions. The total length of current limiting paths was the shortest at the spital shape due to its larger useless space. Inductance component of SFCLs with the spiral shape was around two times as high as those of other two shapes. This is not desirable since impedance characteristics of existing power systems can be changed. Resistance rise of current limiting elements was low at a spiral shape before the whole quench completion, which may act as a disadvantage for simultaneous quench in serial connection between current limiting elements, but the temperature tended to have similar values at higher voltages. On the other hand, hi-spital shape was severe at insulation level between current limiting lines. When these aspects were considered, we concluded that a meander shape was appropriate to design for a resistive SFCL based on thin films except the concentration of electric field at edge areas of strip lines.

Optimized Conditions of Model Processing for Ready-to-eat Style Galbi-jjim Prepared by Sous-vide and Cook-chill System

  • Kim, Kyeong-Mi;Park, Jin-Hee;Shin, Weon-Sun
    • Food Science of Animal Resources
    • /
    • v.29 no.6
    • /
    • pp.673-679
    • /
    • 2009
  • To develop ready-to-eat (RTE) style Korean traditional Galbi-jjim, the optimal conditions for sous-vide cooking and cookchill preparation and the sensory properties of the cooked products were investigated. During heating, the meat core temperatures reached $85^{\circ}C$ within 30 min and 45 min when a water bath and combination oven were used, respectively. Chilling to $3^{\circ}C$ within 45 min was conducted to meet the standards for microbiological safety set by the UK Department of Health and Social Security (DHSS) Guideline. Galbi-jjim that was vacuum-cooked in a water bath was much more tender than that of Galbi-jjim prepared using the cook-chill method, but had no difference in any reheating methods. The average sensory scores of juiciness and the overall acceptance of Galbi-jjim were significantly higher when water bath cooking was used, and there were no differences in reheating methods. In conclusion, the serial methods of sous-vide processing and rapid chilling can be applied to produce RTE traditional Galbi-jjim, and this can be conducted while meeting the standards specified in safety guidelines.

Feldstein-Horioka Puzzle in Thailand and China: Evidence from the ARDL Bounds Testing

  • RUANKHAM, Warawut;PONGPRUTTIKUL, Phoommhiphat
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.8 no.9
    • /
    • pp.1-9
    • /
    • 2021
  • This study aimed to investigate the existence of the Feldstein-Horioka (1980) puzzle in international macroeconomics by applying the conditional Autoregressive Distributed Lag (ARDL) model to examine the long-run relationship between national savings and investments in Thailand and China. The input of this study relied on annual national savings and investments as a fraction of GDP during 1980-2019 which was collected from China National Bureau of Statistics (NBS) and Thailand National Economic and Social Development Council (NESDC). Hypothetically, Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) unit root tests were applied to test the stationary properties and to investigate the integration level of selected time series. The empirical results, confirmed by cumulative sum (CUSUM) and cumulative sum square (CUSUMSQ), maintained no serial correlation and structural break problems. The finding of this study suggested that the Feldstein-Horioka puzzle in Thailand did not exist significantly. Thailand's national savings and investments nexus was independent, following the classic economic idea that financial liberalization, or perfect capital mobility, allowed national savings and investments to flow freely to countries with better interest rates. Whereas, a strong significant correlation was found in the case of China during the fixed exchange rate regime switching in 1994 and post WTO participation after 2001-2019.

Modified partial least squares method implementing mixed-effect model

  • Kyunga Kim;Shin-Jae Lee;Soo-Heang Eo;HyungJun Cho;Jae Won Lee
    • Communications for Statistical Applications and Methods
    • /
    • v.30 no.1
    • /
    • pp.65-73
    • /
    • 2023
  • Contemporary biomedical data often involve an ill-posed problem owing to small sample size and large number of multi-collinear variables. Partial least squares (PLS) method could be a plausible alternative to an ill-conditioned ordinary least squares. However, in the case of a PLS model that includes a random-effect, how to deal with a random-effect or mixed effects remains a widely open question worth further investigation. In the present study, we propose a modified multivariate PLS method implementing mixed-effect model (PLSM). The advantage of PLSM is its versatility in handling serial longitudinal data or its ability for taking a randomeffect into account. We conduct simulations to investigate statistical properties of PLSM, and showcase its real clinical application to predict treatment outcome of esthetic surgical procedures of human faces. The proposed PLSM seemed to be particularly beneficial 1) when random-effect is conspicuous; 2) the number of predictors is relatively large compared to the sample size; 3) the multicollinearity is weak or moderate; and/or 4) the random error is considerable.