• Title/Summary/Keyword: HMA

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Effect of Thermal Segregation Reduction in Asphalt Paving with MTV (MTV를 적용한 아스팔트 포설에서 열분리 저감 효과)

  • Kweon, Gichul
    • International Journal of Highway Engineering
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    • v.20 no.4
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    • pp.1-6
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    • 2018
  • PURPOSES : The objective of this study is to evaluate of the effect of thermal segregation reduction in asphalt paving using material transfer vehicles (MTVs). METHODS : Asphalt paving using MTVs was carried out, and the paved surface temperature was measured using an infrared camera. The amount of thermal segregation was estimated from temperature variations. RESULTS : The transportation of hot mix asphalt (HMA) using dump trucks caused temperature segregation that persisted in the paving surface if an MTV was not used. The average temperature variation was 8.58% in paved surfaces where an MTV was not used. However, the temperature variation was 3.10%, 2.86%, and 4.53% for the base layer, inter-layer, and surface layer, respectively, when an MTV was used. CONCLUSIONS : The use of an MTV in asphalt paving reduces thermal segregation approximately 2.3 times in an asphalt mat via a remixing process and also allows for a smoother work process because the paver never needs to stop to receive HMA. However, MTV equipment without pre-heating devices requires careful temperature control during the warm up process at the MTV during construction in the winter.

Evaluation of Field Application and Laboratory Performance of Warm-Mix Asphalt According to the Dosage Rate of Additive (중온화 첨가제 첨가비율에 따른 현장 적용성 평가 및 실내 역학적 거동 특성 연구)

  • Yang, Sunglin;Baek, Cheolmin;Hwang, Sungdo;Kwon, Soo-Ahn
    • International Journal of Highway Engineering
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    • v.15 no.4
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    • pp.117-125
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    • 2013
  • PURPOSES : The purpose of this study is to evaluate of field application and laboratory performance of warm-mix asphalt (WMA) according to the dosage rate of organic-based WMA additive. METHODS: Three asphalt mixtures, i.e., hot mix asphalt (HMA), WMA with the dosage rate of 1.5%, WMA with the dosage rate of 1.0%, were sampled from the asphalt plant when the field trial project were constructed. With these mixtures, the laboratory testings were performed to evaluate the linear viscoelastic characteristics and the resistance to moisture, rutting and fatigue damage. RESULTS : From the laboratory test results, it was found that the WMA with the reduced dosage rate of additive would be comparable to HMA and WMA with the original dosage rate in terms of the dynamic modulus, tensile strength ratio, rutting resistance. However, the fatigue reisistance of WMA with the reduced dosage rate was slightly worse but it should be noted that the fatigue performance is necessarily predicted by combining the material properties and pavement structure. CONCLUSIONS: Through the field construction and laboratory testings, the dosage rate of organic-based WMA additive could be reduced from 1.5% to 1.0% without the significant decrease of compactability and laboratory performance. The long-term performance of the constructed pavement will be periodically monitored to support the findings from this study.

Design of Linear XY Stage using Planar Configuration and Linear Motors with Halbach Magnet Array (평면형 구조와 Halbach 자석배열 선형모터를 이용한 리니어 XY 스테이지의 설계)

  • Kim, Ki-Hyun;Lee, Moon-G.
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.4
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    • pp.553-561
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    • 2010
  • In flat panel display or semiconductor industries, they install the equipments with fine line width and high throughput for fabrication and inspection. The equipments are required to have the linear stage which can position the work-piece with high speed, fine resolution on wide range of motion. In this paper, a precision planar linear XY stage is proposed. The stage has a symmetric planar window configuration and is guided by air-bearings on granite plate. The symmetric planar window configuration makes the stage has robustness against dynamic and thermal disturbances. The air-bearings let the stage move smooth on straight guide bar and flat granite surface. The stage is actuated by linear motor with Halbach magnet array (HMA). HMA generates more confined magnetic flux than conventional array. The linear motors are optimized by using sequential quadratic programming (SQP) with the several constraints that are thermal dissipation, required power, force ripple and so on. The planar linear XY stage with the symmetric planar configuration and the linear motors is implemented and then the performance such as force ripple, resolution and stroke are evaluated.

Gene functional analysis of Harmonia axyridis by in vitro transcription

  • Park, Sang-Eun;Youn, Young-Nam
    • Korean Journal of Agricultural Science
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    • v.46 no.3
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    • pp.471-488
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    • 2019
  • Random genes were screened in two transforming ways to investigate the new genes of a ladybug using the Harmonia axyridis cDNA library stock cell cloned in the LITMUS 28i vector in a previous study. Phenotypic variation was observed after injection of the synthesized double-stranded RNA through the in vitro transcription process. The cDNA library of H. axyridis was transformed into E. coli $DH5{\alpha}$ and 10B competent cells by heat shock. Analysis of the nucleotide sequences of the 42 clones with the insert DNAs revealed that 21 clones were homologous with the genes of insects, and only one clone had a gene from H. axyridis. Thirteen of the 21 insect genes were homologous with genes from coleopteran insects. Fourteen genes were selected, which were identified by the gene screening results, and were synthesized as double-stranded RNA through in vitro transcription. One microgram of the synthesized double-stranded RNA between segments T1 and T2 were injected using a syringe into each anesthetized fourth larvae which were under 2 days old. As a result, a phenotypic variation appeared in the larva injected with the two genes. While the eggs of H. axyridis injected with distilled water hatched out three days after oviposition, the eggs of H. axyridis injected with dsHma 06 did not hatch but become shrivel a week after oviposition. Most of the H. axyridis injected with dsHma 08 died and were unable to complete the pupation or eclosion during ecdysis.

Signal Transduction Factors on the Modulation of Radiosusceptibility in K562 Cells (K562 세포의 방사선 감수성 변화에 영향을 미치는 신호전달인자)

  • Yang Kwang Mo;Youn Seon-Min;Jeong Soo-Jin;Jang Ji-Yeon;Jo Wol-Soom;Do Chang-Ho;Yoo Y대-Jin;Shin Young-Cheol;Lee Hyung Sik;Hur Won Joo;Lim Young-Jin;Jeong Min-Ho
    • Radiation Oncology Journal
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    • v.21 no.3
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    • pp.227-237
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    • 2003
  • Purpose: The human chronic myelogenous leukemia cell line, K562, expresses the chimeric bcr-abl oncoprotein, whose deregulated protein tyrosine kinase activity antagonizes via DNA damaging agents. Previous experiments have shown that nanomolar concentrations of herbimycin A (HWA) coupled with X-irradiation have a synergistic effect in inducing apoptosis in the Ph-positive K562 leukemia cell line, but genistein, a PTK inhibitor, is non selective for the radiation-induced apoptosils on $p210^{bcr/abl}$ protected K562 cells. In these experiments, the cytoplasmic signal transduction pathways, the Induction on a number of transcription factors and the differential gene expression in this model were investigated. Materials and Methids: K562 cells in the exponential growth phase were used in this study. The cells were irradiated with 0.5-12 Gy, using a 6 Mev Linac (Clinac 1800, Varian, USA). Immediately after irradiation, the cells were treated with $0.25/muM$ of HMA and $25/muM$ of genistein, and the expressions and the activities of abl kinase, MAPK family, NF- kB, c-fos, c-myc, and thymidine kinase1 (TK1) were examined. The differential gene expressions induced by PTK inhibitors were also investigated. Results: The modulating effects of herbimycin A and genistein on the radiosensitivity of K562 cells were not related to the bcr-abl kinase activity. The signaling responses through the MAPK family of proteins, were not involved either in association with the radiation-induced apoptosis, which is accelerated by HMA, the expression of c-myc was increased. The combined treatment of genistein, with irradiation, enhanced NF- kB activity and the TK1 expression and activity. Conclusion: The effects of HMA and genistein on the radiosensitivity on the K562 cells were not related to the bcr-abl kinase activity in this study, another signaling pathway, besides the WAPK family responses to radiation to K562 cells, was found. Further evaluation using this model will provide valuable information for the optional radiosensitization or radioprotection.

Smad6 Gene and Suppression of Radiation-Induced Apoptosis by Genistein in K562 Cells (K562 세포주에서 Genistein에 의해 억제되는 Radiation-induced Apoptosis의 조절 유전자)

  • Jeong, Soo-Jin;Jin, Young-Hee;Yoo, Yeo-Jin;Do, Chang-Ho;Jeong, Min-Ho;Huh, Gi-Yeong;Bae, Hye-Ran;Yang, Kwang-Mo;Moon, Chang-Woo;Oh, Sin-Geun;Hur, Won-Joo;Lee, Hyung-Sik
    • Radiation Oncology Journal
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    • v.19 no.3
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    • pp.245-251
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    • 2001
  • Prupose : The genes involved on the suppression or radiation-induced apoptosis by genistein in K562 leukemia cell line was investigated. Materials and methods : K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For X-ray irradiation and drug treatment, cultures were prepared at $2\times10^5\;cells/mL$. The cells were irradiated with 10 Gy (Clinac 1800C, Varian, USA), Stock solutions of herbimycin A (HMA, Calbiochem, UK) and genistein (Calbiochem, UK) were prepared in dimethylsulfoxide (DMSO, Sigma, UK). After incubation at $37^{\circ}C$ for 24 h, PCR-select cDNA subtractive hybridization, dot hybridization, DNA sequencing and Northern hybridization were examined. Results : Smad6 gene was identified from the differentially expressed genes in K562 cells incubated with genistein which had been selected by PCR-select cDNA subtractive hybridization. The mRNA expression of Smad6 in K562 cells incubated with genistein was also higher than control group by Northern hybridization analysis. Conclusion : We have shown that Smad6 involved on the suppression of radiation-induced apoptosis by genistein in K562 leukemia cell line. It is plausible that the relationship between Smad6 and the suppression of radiation-induced apoptosis is essential for treatment development based on molecular targeting designed to modify radiation-induced apoptosis.

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Biopolymer Amended Soil Reduces the Damages of Zn Excess in Camlina sativa L. (토양 내 바이오폴리머 혼합에 의한 Camelina sativa L.의 Zn 과잉 스트레스 피해 경감 효과)

  • Shin, Jung-Ho;Kim, Hyun-Sung;Kim, Eunsuk;Ahn, Sung-Ju
    • Ecology and Resilient Infrastructure
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    • v.7 no.4
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    • pp.262-273
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    • 2020
  • Amending biopolymers such as β-glucan (BG) and Xanthan gum (XG) generally enhances soil strength by ionic and hydrogen bonds between soil particles. Thus, biopolymers have been studied as eco-friendly construction materials in levees. However, physiological responses of plants grown on soil amended with biopolymers are not fully understood. This study focuses on the effects of biopolymers on the growth of Camelina sativa L. (Camelina) under excess zinc (Zn) stress. The optimal concentrations of BG and XG were confirmed to have a 0.5% ratio in soil depending on the physiological parameters of Camelina under excess Zn stress. The Zn binding capacity of biopolymers was investigated using 1,5-diphenylthiocarbazone (DTZ). The reduction of Zn damage in Camelina was evaluated by analyzing the Zn content and expression of heavy metal ATPase (HMA) genes under excess Zn stress. Amendments of BG and XG improved Camelina growth under excess Zn stress. In DTZ staining and ICP-OES analysis, Camelina grown on BG and XG soil showed less Zn uptake than normal soil under excess Zn stress. The Zn-inducible CsHMA3 gene was not stimulated by either BG or XG amendment under excess Zn stress. Moreover, both BG and XG amendments in soil exhibit Zn-stress mitigation similar to that of Zn-tolerant CsHMA3 overexpres sed Camelina. These results indicate that biopolymer-amended soils may influence the prevention of Zn absorption in Camelina under excess Zn stress. Thus, BG and XG are proven to be suitable materials for levee construction and can protect plants from soil contamination by Zn.

Reactivation of Silenced WT1 Transgene by Hypomethylating Agents - Implications for in vitro Modeling of Chemoimmunotherapy

  • Kwon, Yong-Rim;Son, Min-Jung;Kim, Hye-Jung;Kim, Yoo-Jin
    • IMMUNE NETWORK
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    • v.12 no.2
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    • pp.58-65
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    • 2012
  • Background: A cell line with transfected Wilms' tumor protein 1 (WT1) is has been used for the preclinical evaluation of novel treatment strategies of WT1 immunotherapy for leukemia due to the lack of appropriate murine leukemia cell line with endogenous WT1. However, silencing of the transgene occurs. Regarding the effects of hypomethylating agents (HMAs) on reactivation of silenced genes, HMAs are considered to be immune enhancers. Methods: We treated murine WT1- transfected C1498 (mWT1-C1498) with increasing doses of decitabine (DAC) and azacitidine (AZA) to analyze their effects on transgene reactivation. Results: DAC and AZA decreased the number of viable cells in a dose- or time-dependent manner. Quantification of WT1 mRNA level was analyzed by real-time polymerase chain reaction after mWT1-C1498 treated with increasing dose of HMA. DAC treatment for 48 h induced 1.4-, 14.6-, and 15.5-fold increment of WT1 mRNA level, compared to untreated sample, at 0.1, 1, and $10{\mu}M$, respectively. Further increment of WT1 expression in the presence of 1 and $10{\mu}M$ DAC was evident at 72 h. AZA treatment also induced up-regulation of mRNA, but not to the same degree as with DAC treatment. The correlation between the incremental increases in WT1 mRNA by DAC was confirmed by Western blot and concomitant down-regulation of WT1 promoter methylation was revealed. Conclusion: The in vitro data show that HMA can induce reactivation of WT1 transgene and that DAC is more effective, at least in mWT1-C1498 cells, which suggests that the combination of DAC and mWT1-C1498 can be used for the development of the experimental model of HMA-combined WT1 immunotherapy targeting leukemia.

A Study on Mechanical Characteristics of Fiber Modified Emulsified Asphalt Mixture as Environmentally-Friend Paving Material (섬유보강 친환경 상온아스팔트 혼합물의 역학적 특성에 관한 연구)

  • Rhee Suk-Keun;Park Kyung-Won
    • International Journal of Highway Engineering
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    • v.8 no.2 s.28
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    • pp.23-30
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    • 2006
  • Emulsified Asphalt Mixture(EAM) is more environmentally-friendly and cost-effective than typical Hot Mix Asphalt (HMA) because EAM does not produce carcinogenic substances, e.g., naphtha, kerosene, during the both of manufacturing and roadway construction process. Also, it does not require heating the aggregates and asphalt binder. However, EAM has some disadvantages. Generally EAM has a less load bearing capacity and more moisture susceptibility than conventional HMA. The study evaluated a Fiber modified EAM (FEAM) to increase load bearing capacity and to decrease moisture susceptibility of EAM. Modified Marshall mix design was developed to find Optimum Emulsion Contents (OEC), Optimum Water Contents (OWC), and Optimum Fiber Contents (OFC). A series of test were performed on the fabricated specimen with OBC, OWC, and OFC. Tests include Marshall Stability, Indirect Tensile Strength, and Resilient modulus test. Comparison analyses were performed among EAM, Fiber modified EAM (FEAM), and typical HMA to verify the applicability of EAM and FEAM in the field. Test results indicated that both of EAM and FEAM have an enough capability to resist medium traffic volume based on the Marshall mix design criteria. Also the study found that fiber modification is effective to increase the load bearing capacity and moisture damage resistance of EAM.

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