• Title/Summary/Keyword: PBX

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A Study on the Phase Formation Process in Bi-system Superconductor with Heat Treatment Conditions (열처리 조건에 따른 Bi계 초전도체에서 상 생성 과정에 대한 연구)

  • 정진인;이준웅;박용필
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.221-223
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    • 1999
  • In this work, samples were manufactured variously by changing conventional calcining and sintering conditions and we tried the utilization by making the heat treatment time, which is demanded to high-Tc phase formation, much shorter. We found out optimal heat treatment conditions with the analysis on formation process at superconducting phase in term of the change of calcining and sintering time and then, examined X-ray diffraction(XRD) patterns, scanning electron microscope(SEM) measurement and energy dispersive X-ray spectrometer(EDX) of the samples manufactured under heat treatment conditions which we suggest here. As a result, 2223 high-$T_c$, phase of (Bi,Pb)SrCaCuO superconductor starting with ($Bi_l$ xPbx,)$_2$$Sr_2$$Ca_2$$Cu_3$$O_y$, composition was formed from 1 hr sintering sample at temperature nearby melting point and also the completed sample with calcining and sintering time of 9 hr was formed high-$T_c$.low-$T_c$ phase appearing in sight above the critical temperature of liquid $N_2$.

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Process Development for Recovery of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine from Compressible Polymer-Bonded Explosives Through the Pretreatment of Polymer Binders (폴리머 바인더의 선처리를 통한 압축형 복합화약으로부터 octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine의 회수 공정 개발)

  • Kim, Hyejoo;Kim, DongWoo;Huh, Eugene;Park, Sewon;Lee, Chang-Ha;Ahn, Ik-Sung;Lee, Keun Deuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.5
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    • pp.523-531
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    • 2020
  • Extraction and anti-solvent crystallization were proposed to recover octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) from pressed polymer bonded explosives(PBXs). DXC-57 and DXC-59, whose polymeric binders are Estane and HyTemp with dioctyl adipate plasticizer, respectively, were used as pressed PBX models. Estane of DXC-57 was removed by washing with tetrahydrofuran prior to extraction, which enabled the crystallization of HMX at a low degree of supersaturation, sufficient to obtain β-form HMX. Using dimethyl sulfoxide and ethanol as the extraction solvent and the anti-solvent for crystallization, respectively, HyTemp and dioctyl adipate in DXC-59 were separated from HMX. The purity of recovered β-form HMX was higher than 99 %.

Weighted Gene Co-expression Network Analysis in Identification of Endometrial Cancer Prognosis Markers

  • Zhu, Xiao-Lu;Ai, Zhi-Hong;Wang, Juan;Xu, Yan-Li;Teng, Yin-Cheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4607-4611
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    • 2012
  • Objective: Endometrial cancer (EC) is the most common gynecologic malignancy. Identification of potential biomarkers of EC would be helpful for the detection and monitoring of malignancy, improving clinical outcomes. Methods: The Weighted Gene Co-expression Network Analysis method was used to identify prognostic markers for EC in this study. Moreover, underlying molecular mechanisms were characterized by KEGG pathway enrichment and transcriptional regulation analyses. Results: Seven gene co-expression modules were obtained, but only the turquoise module was positively related with EC stage. Among the genes in the turquoise module, COL5A2 (collagen, type V, alpha 2) could be regulated by PBX (pre-B-cell leukemia homeobox 1)1/2 and HOXB1(homeobox B1) transcription factors to be involved in the focal adhesion pathway; CENP-E (centromere protein E, 312kDa) by E2F4 (E2F transcription factor 4, p107/p130-binding); MYCN (v-myc myelocytomatosis viral related oncogene, neuroblastoma derived [avian]) by PAX5 (paired box 5); and BCL-2 (B-cell CLL/lymphoma 2) and IGFBP-6 (insulin-like growth factor binding protein 6) by GLI1. They were predicted to be associated with EC progression via Hedgehog signaling and other cancer related-pathways. Conclusions: These data on transcriptional regulation may provide a better understanding of molecular mechanisms and clues to potential therapeutic targets in the treatment of EC.

Rheology and Curing of Hydroxyl Terminated Polybutadiene/(Sugar or Calcium Carbonate) Suspension (Hydroxyl Terminated Polybutadiene/(설탕 또는 탄산칼슘) 현탁계의 유변물성 및 경화특성)

  • Lee, Sangmook;Hong, In-Kwon;Lee, Jae Wook;Jeong, Won Bok
    • Polymer(Korea)
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    • v.38 no.4
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    • pp.417-424
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    • 2014
  • Reactivity and rheological behavior of highly concentrated polymer bonded explosives (PBX) simulant was studied. As a binder, thermosetting hydroxyl terminated polybutadiene (HTPB) was used. By using bimodal $CaCO_3$ (size ratio 10:1) and sugar particles (size ratio 25:1) as fillers, maximum 75 v% filling was possible during melt mixing. The relative viscosities of bimodal suspension were much lower than those of unimodal one and showed minimum values at 0.25 of fine particle fraction. In curing experiment, as curing temperature increased, the time of initiation and completeness of curing reaction became shortened, the torque kept low, and the change of internal temperature decreased.

Estimation of Rheological Properties of Highly Concentrated Polymer Bonded Explosive Simulant by Microstructure Analysis (미세구조 해석을 통한 고농축 복합화약 시뮬란트의 유변물성 예측)

  • Lee, Sangmook;Hong, In-Kwon;Lee, Jae Wook;Shim, Jung Seob
    • Polymer(Korea)
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    • v.38 no.2
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    • pp.225-231
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    • 2014
  • The rheological properties of highly concentrated polymer bonded explosive simulant were studied by using poly(ethylene-co-vinyl acetate) with 30 and 60% vinyl acetate (VA) content as a binder, respectively. Calcium carbonate and Dechlorane, whose physical properties are similar to resarch department explosive (RDX)'s, were used as fillers. The suspensions were mixed in a batch melt mixer and it was possible to fill 75 v% at maximum. From dynamic mechanical analysis, Dechlorane showed higher interaction with binder resins than that with calcium carbonate fillers. The effects of microstructural change on the rheological properties of the suspensions were investigated by a plate-plate rheometer with constant shear rate and constant shear stress modes, respectively. The theoretical maximum packing fraction of EVA31/Dechlorane suspension obtained from Krieger-Dougherty equation was 70 v% and it was thought that 2000 Pa was proper shear stress condition for this melt processing.

Five Most Common Prognostically Important Fusion Oncogenes are Detected in the Majority of Pakistani Pediatric Acute Lymphoblastic Leukemia Patients and are Strongly Associated with Disease Biology and Treatment Outcome

  • Awan, Tashfeen;Iqbal, Zafar;Aleem, Aamer;Sabir, Noreen;Absar, Muhammad;Rasool, Mahmood;Tahir, Ammara H.;Basit, Sulman;Khalid, Ahmad Mukhtar;Sabar, Muhammad Farooq;Asad, Sultan;Ali, Agha Shabbir;Mahmood, Amer;Akram, Muhammad;Saeed, Tariq;Saleem, Arsalan;Mohsin, Danish;Shah, Ijaz Hussain;Khalid, Muhammad;Asif, Muhammad;Haq, Riazul;Iqbal, Mudassar;Akhtar, Tanveer
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5469-5475
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    • 2012
  • Background and Objectives: Acute lymphoblastic leukemia (ALL) is a complex genetic disease involving many fusion oncogenes (FO) having prognostic significance. The frequency of various FO can vary in different ethnic groups, with important implications for prognosis, drug selection and treatment outcome. Method: We studied fusion oncogenes in 101 pediatric ALL patients using interphase FISH and RT-PCR, and their associations with clinical features and treatment outcome. Results: Five most common fusion genes i.e. BCR-ABL t (22; 9), TCF3-PBX1 (t 1; 19), ETV6-RUNX1 (t 12; 21), MLL-AF4 (t 4; 11) and SIL-TAL1 (del 1p32) were found in 89/101 (88.1%) patients. Frequency of BCR-ABL was 44.5% (45/101). BCR-ABL positive patients had a significantly lower survival ($43.7{\pm}4.24$ weeks) and higher white cell count as compared to others, except patients with MLL-AF4. The highest relapse-free survival was documented with ETV6-RUNX1 (14.2 months) followed closely by those cases in which no gene was detected (13.100). RFS with BCR-ABL, MLL-AF4, TCF3-PBX1 and SIL-TAL1 was less than 10 months (8.0, 3.6, 5.5 and 8.1 months, respectively). Conclusions: This is the first study from Pakistan correlating molecular markers with disease biology and treatment outcome in pediatric ALL. It revealed the highest reported frequency of BCR-ABL FO in pediatric ALL, associated with poor overall survival. Our data indicate an immediate need for incorporation of tyrosine kinase inhibitors in the treatment of BCR-ABL+ pediatric ALL in this population and the development of facilities for stem cell transplantation.

Electrical Properties in $Pt/SrTiO_3/Pb_x(Zr_{0.52}, Ti_{0.48})O_3/SrTiO_3/Si$ Structure and the Role of $SrTiO_3$ Film as a Buffer Layer ($Pt/SrTiO_3/Pb_x(Zr_{0.52}, Ti_{0.48})O_3/SrTiO_3/Si$ 구조의 전기적 특성 분석 및 $SrTiO_3$박막의 완충층 역할에 관한 연구)

  • 김형찬;신동석;최인훈
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.6
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    • pp.436-441
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    • 1998
  • $Pt/SrTiO_3/Pb_x(Zr_{0.52}, Ti_{0.48})O_3/SrTiO_3/Si$ structure was prepared by rf-magnetron sputtering method for use in nondestructive read out ferroelectric RAM(NDRO-FEAM). PBx(Zr_{0.52}Ti_{0.48})O_3}$(PZT) and $SrTiO_3$(STO) films were deposited respectively at the temperatures of $300^{\circ}C and 500^{\circ}C$on p-Si(100) substrate. The role of the STO film as a buffer layer between the PZT film and the Si substrate was studied using X-ray diffraction (XRD), Auger electron spectroscopy (ASE), and scanning electron microscope(SEM). Structural analysis on the interfaces was carried out using a cross sectional transmission electron microscope(TEM). For PZT/Si structure, mostly Pb deficient pyrochlore phase was formed due to the serious diffusion of Pb into the Si substrate. On the other hand, for STO/PZT/STO/Si structure, the PZT film had perovskite phase and larger grain size with a little Pb interdiffusion. the interfaces of the PZT and the STO film, of the STO film and the interface layer and $SiO_2$, and of the $SiO_2$ and the Si substate had a good flatness. Across sectional TEM image showed the existence of an amorphous layer and $SiO_2$ with 7nm thickness between the STO film and the Si substrate. The electrical properties of MIFIS structure was characterized by C-V and I-V measurements. By 1MHz C-V characteristics Pt/STO(25nm)/PZT(160nm)/STO(25nm)/Si structure, memory window was about 1.2 V for and applied voltage of 5 V. Memory window increased by increasing the applied voltage and maximum voltage of memory window was 2 V for V applied. Memory window decreased by decreasing PZT film thickness to 110nm. Typical leakage current was abour $10{-8}$ A/cm for an applied voltage of 5 V.

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