• Title/Summary/Keyword: Segregation

Search Result 1,183, Processing Time 0.033 seconds

Centerline Segregation of Pipe Plate made of API 5L X65 Steel (배관 강재 API 5L X65의 중심편석)

  • Choe, Byung Hak;Lee, Sang Woo;Kim, Woo Sik;Kim, Cheol Man
    • Journal of the Korean Institute of Gas
    • /
    • v.24 no.5
    • /
    • pp.39-46
    • /
    • 2020
  • This paper is considered about centerline segregation of API 5L steel used in pipeline. Mn/S, Nb and C were known as segregated elements in the centerline of pipe thickness. The Mn usually was accompanied by S consisting of long viscous shape. Microstructure of the centerline was composed of MnS and Nb/Ti indusions including oxide. The segregation effect in centerline region was analyzed by OM, SEM/EDS and micro Vickers hardness. The Mn, Nb and C are retarded elements in transformation from austenite to ferrite or martensite. These elements could derive a bainitic microstructure as a kind of martensite, which is different from difference and element segregation between in matrix and centerline derived from steel melting and heat treatment.

Genetic Epidemiological Analysis of Esophageal Cancer in High-incidence Areas of China

  • Wang, Kai-Juan;Yang, Jun-Xia;Shi, Jia-Chen;Deng, Song-Yuan;Cao, Xiao-Qin;Song, Chun-Hua;Wang, Peng
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.22
    • /
    • pp.9859-9863
    • /
    • 2014
  • Genetic epidemiological studies have shown that genetic susceptibility to esophageal cancer (EC) is an important cause of its high incidence within families in some areas of China. The purpose of this study was to obtain evidence of a genetic basis of EC in Xin-an and Xin-xiang counties in China. Familial aggregation and complex segregation analyses were performed of 79 EC families in these counties. The heritability of EC was examined using Falconer's method and complex segregation analysis was conducted with the SEGREG program in Statistical Analysis for Genetic Epidemiology (SAGE version 5.3.1). The results showed that the distribution of EC in families did not fit well into a binomial distribution. The heritability of EC among first-degree and second-degree relatives was $67.0{\pm}7.31%$ and $43.1%{\pm}9.80%$, respectively, and the summing up powered heritability was $53.2{\pm}6.74%$. The segregation ratio was 0.045. Complex segregation analysis showed that the genetic model of EC was additive. The current results provide evidence for an inherited propensity to EC in certain high-risk groups in China, and support efforts to identify the genes that confer susceptibility to this disease.

Analysis of Non-segregated S-allele Strain by Single-Locus Hypothesis in Self-incompatible Brassica campestris (자가불화합성 Brassica campestris에 있어서 단일유전자좌가설에 의해 분리되지 않는 S-유전자 계통의 분석)

  • 노일섭
    • Journal of Plant Biology
    • /
    • v.36 no.2
    • /
    • pp.127-132
    • /
    • 1993
  • Self-incompatibility in Brassica campestris is controlled by multi-allele system in a single genetic locus, the S locus, and it is elucidated that S-glycoproteins are S gene products. In this experiments, we examined the genetic mode(pollen tube behavior and segregation of S-glycoprotein), characteristic of S-glycoproteins and DNA constitution within nuclear genome on S gene family that unexplained by single locus model, and investigated the segregation pattern of S-glycoproteins in bred F1 generation. By diallel cross among the 15 plants within one family the existence of three types of homozygotes and three types of heterozygotes were observed, and segregation of S-allele could not explained by single locus model. From the results of IEF-immunoblot analysis for non-segregated individual plant, the segregation pattern of S specific bands was corresponded with results of diallel cross except with one case(SaSa genotype). The molecular weight of 6 different S-genotype varied in near by 50 kD, and each genotype expressed with 2 or 3 bands. Specific bands in SaSa, SbSb, ScSc has almost similar molecular weight between them. Southern analysis of genomic DNA probed with S-glycoprotein cDNA for 6 different genotypes revealed that there are clear difference in polymorphism, multiple bands of hybridization, when restriction enzymes of EcoR I were used. It could be assumed that there are several sequences related to the S-glycoprotein structural genes within their nuclear genome. Therefore, we suggested the possibilities that S-allele system could be controlled by multi-locus, that dominance-recessive interactions could be explained by modifier gene or supressor gene based on the results of abnormal segregation of S-glycoprotein in bred F1. The F2 analyses are progressing in now.

  • PDF

A Study on the Effect of Improvement in Work Environment and of Segregation in a Fluorescent Lamp Manufacturing Factory (모 수은취급사업장의 작업환경 개선 및 근로자 작업전환 효과에 관한 연구)

  • Chang, Soung-Hoon;Kim, Kwang-Jong
    • Journal of Preventive Medicine and Public Health
    • /
    • v.22 no.4 s.28
    • /
    • pp.474-479
    • /
    • 1989
  • This research was conducted to evaluate the effect of improvement in work environment and of segregation in a fluorescent lamp manufacturing factory. Among the total of 80 workers, 8 workers whose mercury concentration in urine reached a hazardous level ($200-299{\mu}g/l$) were moved to mercury free workplace. The follow-up examination for their mercury concentration in urine was done three times ; on May 3, 1988, September 1, 1988 and April 3, 1989. The results were as follows : 1. Mercury concentration in the air was reduced from 0.140 to 0.107 $mg/m^3$ in 4 months, and to $0.087mg/m^3$ in one year after environmental improvement in workplace. However the level still exceeded the Threshold Limit Value. 2. The geometric mean of urinary mercury concentration among 80 workers was $173.0{\mu}g/l\;(5.1{\sim}458.6{\mu}g/l$). The distribution of workers according to urinary mercury concentration showed that 9 workers (11.2%) were above the mercury poisoning level ($300{\mu}g/l$), 24 workers (30.0%) were $200-299{\mu}g/l$, 35 workers (43.8%) were $50-199{\mu}g/l$, and 12 workers (15.0%) were below 50 ${\mu}g/l$. 3. Among the 24 workers whose urinary mercury concentration was 200-299 $50-199{\mu}g/l$, 8 were able to be followed up. Their mean urinary mercury concentration before segregation was $244.9{\mu}g/l$, but decreased to $151.4{\mu}g/l$ in four months, $128.8{\mu}g/l$ in six months, and $46.8{\mu}g/l$ in one year after segregation.

  • PDF

Numerical Model with Segregation Potential on Frost Heave and Reliability Assessment for Silty Soils (Segregation Potential 기반 동상 예측 모델 및 실트질 토양을 이용한 동상해석 신뢰성 평가)

  • Jangguen Lee;Zheng Gong;Hyunwoo Jin;Byunghyun Ryu
    • Journal of the Korean GEO-environmental Society
    • /
    • v.24 no.9
    • /
    • pp.41-46
    • /
    • 2023
  • Numerical analysis of frost heave is challenging due to the influence of soil and environmental factors. Thermo-hydromechanical coupled analysis relies heavily on excessive input variables and primarily focuses on validating clayey soils, so it is limited to frost susceptible silty soils. An empirical approach based on thermodynamics offers relatively simple frost heave analysis and the advantage of linking constitutive equations with frost heave to enable geomechanical interpretations. In this paper, we introduce an empirical numerical model using the Segregation Potential (SP) and evaluate reliability through comparative analysis with experimental results of frost susceptible silty soils. While the SP model enables frost heave analysis for the given silty soils, further investigation on various silty soils is necessary to gather data on key input variables.

How Chromosome Mis-Segregation Leads to Cancer: Lessons from BubR1 Mouse Models

  • Lee, Hyunsook
    • Molecules and Cells
    • /
    • v.37 no.10
    • /
    • pp.713-718
    • /
    • 2014
  • Alteration in chromosome numbers and structures instigate and foster massive genetic instability. As Boveri has seen a hundred years ago (Boveri, 1914; 2008), aneuploidy is hall-mark of many cancers. However, whether aneuploidy is the cause or the result of cancer is still at debate. The molecular mechanism behind aneuploidy includes the chromosome mis-segregation in mitosis by the compromise of spindle assembly checkpoint (SAC). SAC is an elaborate network of proteins, which monitor that all chromosomes are bipolarly attached with the spindles. Therefore, the weakening of the SAC is the major reason for chromosome number instability, while complete compromise of SAC results in detrimental death, exemplified in natural abortion in embryonic stage. Here, I will review on the recent progress on the understanding of chromosome missegregation and cancer, based on the comparison of different mouse models of BubR1, the core component of SAC.

Genetic analysis of protoplast fusants of candida pseudotropicalis (Candida pseudotropicalis 융합세포의 유전적 분석)

  • Chun, Soon-Bai;Bai, Suk
    • Korean Journal of Microbiology
    • /
    • v.26 no.2
    • /
    • pp.82-87
    • /
    • 1988
  • The genetic analysis and characterization of protoplast fusion hybrids between complementary auxotrophic mutants of Candida pseudotropicalis were carried out. Nuclear fusion appeared to occur in fusion hybrids (e.g., F15 and F33), as strongly suggested by isolation of recombinants after mitotic segregation of parental genetic markers. This was confirmed by KNA content, nuclear staining and comparison of survival rate to UV light. After keeping fusion hybrids for approximately one year, the frequency of spontaneous mitotic segregation was $3.0\times 10^{-4}$ - $8.1\times 10^{-4}$ while that of induced mitotic segregation was $1.4\times 10^{-3}$- $1.7\times 10^{-3}$. These results suggested that they maintained stable karyogamy state. It was also found that the production of $\beta$-D-galactosidase from F15, F33 and F158 was somewhat increased when compared with that from either auxotrophic parents or wild type.

  • PDF

Particle Flow Analysis of Grain-Size Controlled Rheology Materials (결정립제어 레오로지 소재의 입자유동 해석)

  • 김현일;강충길
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2004.10a
    • /
    • pp.774-777
    • /
    • 2004
  • A rheology casting technology has some advantages compared with conventional forming processes such as die casting, squeeze casting and hot/cold forming. The liquid segregation is important on mechanical properties of materials using rheology casting. In this study, so, molecular dynamics simulations were performed for the control of liquid segregation. Because the dynamics of fluid flow about nano-scaled materials is completely different from continuum, molecular dynamics simulations were used. The behavior of particles was far from the truth according to boundary conditions in simple flow. But various movement of particles appear at two or more molecular simulations.

  • PDF

Practical Use of Self-compacting Concrete by Hydraulic Composition Containing a Segregation-Reducing Agent (수경성 물질용 분리저감제를 사용한 무다짐 콘크리트 실용화 연구)

  • 손유신;이승훈;김규동;김경태
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2001.11a
    • /
    • pp.275-280
    • /
    • 2001
  • Recently, self-compacting concrete is applied in order to achieve workability improvement and rationalization in construction. But self-compacting concrete using viscosity agent has a difficulty in practical use because viscosity agent is invested small quantity and by man-power. Therefore in this paper we have been focused on the development and practical use of self-compacting concrete by hydraulic composition containing the segregation-reducing agent. According to mix variable, we find out right quantity of water, binder and rate of admixture replacement, and also we find out the optimum mix proportion. In the result, self-compacting concrete by hydraulic composition containing the segregation reducing agent gave satisfaction with standard and its demand will increase in the future.

  • PDF

A Study on the Material Resistance Against Segregation of Cement Mortar in Water (수중에서 시멘트 모르타르의 재료분리저항성에 관한 연구)

  • 정민철;남기웅;정윤중
    • Journal of the Korean Ceramic Society
    • /
    • v.31 no.9
    • /
    • pp.941-948
    • /
    • 1994
  • An underwater grout on material resistance against segregation in water were studied by water soluble polymer (methyl cellulose and acrylic acid ester and styrene). The mechanical properties of the grout agents were investigated through the observation of the microstructure and application of fracture mechanic. When the soluble polymer MC+AAES added with 0.6 wt% to the underwater grout agents the compressive strength, flexural strength and Young's modulus were about 58 MPa, 10 MPa and 3.2 GPa respectively, and critical stress intensity was about 0.8 MNm-1.5. It can be considered that the strength improvement and fracture toughness increase may be due to the pore decrease and bonding force by material resistance against segregation in water.

  • PDF