• 제목/요약/키워드: AH-1

검색결과 5,329건 처리시간 0.036초

공격헬기 개발을 위한 무장 비행시험 탄약발수 최적화 연구 (A Study for Optimization of Armed Flight Test Ammunition Requirement for the Development of Attack Helicopter)

  • 이명석;허장욱
    • 한국산학기술학회논문지
    • /
    • 제21권8호
    • /
    • pp.147-153
    • /
    • 2020
  • 헬기와 같은 항공기의 신규 개발에는 시제품 설계 및 제작과 함께 많은 시간동안 비행시험을 통한 안전성 검증이 요구된다. 비행시험을 수행하는 시험평가 단계는 시스템의 개발에 있어 성공을 좌우하는 중요한 과정이며, 특히, 공격헬기 개발을 위해서는 무장분야 비행시험을 통한 안전성 검증이 매우 중요하다. 이러한 공격헬기의 개발에 있어서 무장분야 비행시험 관련 시험평가 기간 및 비용은 비행시험의 소요탄약 발수와 밀접한 관계가 있다. 따라서, 본 논문에서는 미 군사 규격인 ADS-44-HDBK와 유사 사례로 AH-1 헬기의 분석을 통해 공격헬기 개발 간 무장분야 비행시험에 요구되는 탄약소요량을 제시하였다. AH-1 헬기의 사례 분석을 통해 중복 사격시험 배제 및 형상차이를 고려하여 탄약 요구량 산출이 가능하며, 기관총 장착 형상의 경우 사격시험 관련 탄약이 약 10,500R 요구되고, 로켓 장착 형상의 경우 사격시험 관련 탄약이 약 324R 요구된다. 또한, 무장통합벤치를 적절하게 사용을 한다면 무장분야 비행시험간 발생 가능한 위험요소 식별하여 미연에 배제함으로써 무장분야 비행시험의 효율적 추진이 예상된다.

Regulation of CYP 1A1 gene expression by retinoic acid receptor, retinoid X receptor and constitutive androstane receptor in rainbow trout hepatoma cells(RTH 149)

  • Kim, Ji-Sun;Yang, So-Yeun;Seo, Mi-Jung;Sheen, Yhun-Yhong
    • 한국응용약물학회:학술대회논문집
    • /
    • 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
    • /
    • pp.89-89
    • /
    • 2003
  • Exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes a variety of biological and toxicology effects, most of which are mediated by aryl hydrocarbon receptor (AhR). The ligand-bound AhR as a heterodimer with AhR nuclear translocator (ARNT) binds to its specific DNA recognition site, the dioxin-responsive element (DRE), and it results in increased transcription of CYP1A1 gene. Retinoic acid (RA) regulates the transcription of various genes for several essential functions through binding to two classes of nuclear receptors, the retinoic acid receptor (RAR) and retinoid X receptor (RXR). Constitutive androstane receptor (CAR) also regulates the transcription of gene. In this study, we have examined how RAR, RXR and CAR regulated CYP1A1 in rainbow trout hepatoma cell (RTH 149) using luciferase reporter gene assay system. We did transient transfection with CYP1A1 luciferase reporter gene and treated with TCDD, all-trans RA, 9-cis RA and phenobarbital. Treatment of all-trans RA, 9-cis RA or phenobarbital decreased the TCDD induced transcription of CYP1Al. When we did transient cotransfection with CYP1A1 luciferase reporter gene and RXR, as increase of RXR concentration, the TCDD induced transcription of CYP1A1 was decreased. Transfection with CAR also decreased the TCDD induced transcription of CYP1A1 in RTH 149 cells.

  • PDF

리튬 폴리머 전지용 $LiFe_xMn_{1-x}PO_4$ 정극활물질의 전기화학적 특성 (The electrochemical properties of $LiFe_xMn_{1-x}PO_4$ cathode materials for lithium polymer batteries)

  • 전대규;구할본
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
    • /
    • pp.424-425
    • /
    • 2005
  • The purpose of this study is to research and develop $LiFe_xMn_{1-x}PO_4$ cathode for lithium polymer batteries. $LiFe_xMn_{1-x}PO_4$ cathode active materials were prepared using a solid-state reaction by adding carbon black to the synthetic precursors. We investigated cyclic voltammetry and charge/discharge cycling of $LiFe_xMn_{1-x}PO_4$/SPE/Li cells. The discharge capacity of $LiFe_{0.5}Mn_{0.5}PO_4$ was l26mAh/g and 110mAh/g at 1st and 10th cycle.

  • PDF

C/EBP$\beta$ mediated inhibition of PAH-inducible CYPlAl expression by Oltipraz, a cancer chemopreventive agent

  • Cho, Il-Je;Kim, Sang-Geon
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
    • /
    • pp.85.3-86
    • /
    • 2003
  • Oltipraz, a cancer chemopreventive agent, induces CYP1A1 to a certain extent by transactivation of the gene via the Ah receptor (AhR)-xenobiotic response element (XRE) pathway. Previously, we showed that oltipraz promoted CCAAT/enhancer binding protein (C/EBP ) activation, which leads to the induction of glutathione S-transferase. Given that oltipraz activates C/EBP for gene transactivation and that the putative C/CBP binding site is located in CY)1A1 promoter region, this study investigated the effect of oltipraz on CYP1A1 induction by 3-methylcholanthrene (3-MC). (omitted)

  • PDF

리튬이온이차전지 음극활물질로써 주석을 첨가한 열분해탄소의 합성과 특성평가 (Synthesis and Characterization of Tin-Pyrolyzed Carbon Composites as Anode Material for Lithium Ion Secondary Batteries)

  • 황윤주;박상호;김애란;;;서은경;남기석
    • 에너지공학
    • /
    • 제19권1호
    • /
    • pp.16-20
    • /
    • 2010
  • 본 연구에서는 바이오매스로 커피원두를 이용하여 합성한 카본재료에 도전재로 주석을 이용하였다. 주석을 첨가하는 방법에 따라 단순 혼합, 화학적인 방법을 이용하여 혼합체를 만들어 시료를 합성하였다. 시료에 대한 XRD를 이용하여 주석과 탄소가 혼합된 구조를 가지고 있음을 확인하였고 SEM을 통한 합성된 시료구입자크기($12{\sim}85\;{\mu}m$)와 형태를 확인하였다. 충 방전 테스트를 실시하여 15사이클에서 카본블랙을 사용했을 때(105 mAh/g)보다 주석을 화학적으로 혼합을 시킨 시료의 경우(191 mAh/g)가 방전용량이 더 높게 나타나는 것을 볼 수 있었고, 주석을 단순 혼합을 실시한 경우에서는 카본블랙과 비슷한 용량(131 mAh/g)을 보였다.

Efficacy of genotype-matched Newcastle disease virus vaccine formulated in carboxymethyl sago starch acid hydrogel in chickens vaccinated via different routes

  • Mahamud, Siti Nor Azizah;Bello, Muhammad Bashir;Ideris, Aini;Omar, Abdul Rahman
    • Journal of Veterinary Science
    • /
    • 제23권4호
    • /
    • pp.25.1-25.14
    • /
    • 2022
  • Background: The commercially available Newcastle disease (ND) vaccines were developed based on Newcastle disease virus (NDV) isolates genetically divergent from field strains that can only prevent clinical disease, not shedding of virulent heterologous virus, highlighting the need to develop genotype-matched vaccines Objectives: This study examined the efficacy of the NDV genotype-matched vaccine, mIBS025 strain formulated in standard vaccine stabilizer, and in carboxymethyl sago starch-acid hydrogel (CMSS-AH) following vaccination via an eye drop (ED) and drinking water (DW). Methods: A challenge virus was prepared from a recent NDV isolated from ND vaccinated flock. Groups of specific-pathogen-free chickens were vaccinated with mIBS025 vaccine strain prepared in a standard vaccine stabilizer and CMSS-AH via ED and DW and then challenged with the UPM/NDV/IBS362/2016 strain. Results: Chickens vaccinated with CMSS-AH mIBS025 ED (group 2) developed the earliest and highest Hemagglutination Inhibition (HI) NDV antibody titer (8log2) followed by standard mIBS025 ED (group 3) (7log2) both conferred complete protection and drastically reduced virus shedding. By contrast, chickens vaccinated with standard mIBS025 DW (group 5) and CMSS-AH mIBS025 DW (group 4) developed low HI NDV antibody titers of 4log2 and 3log2, respectively, which correspondingly conferred only 50% and 60% protection and continuously shed the virulent virus via the oropharyngeal and cloacal routes until the end of the study at 14 dpc. Conclusions: The efficacy of mIBS025 vaccines prepared in a standard vaccine stabilizer or CMSS-AH was affected by the vaccination routes. The groups vaccinated via ED had better protective immunity than those vaccinated via DW.

ARYL HYDROCARBON- AND ESTROGEN-MEDIATED SIGNALS POSSIBLY CROSS TALK TO REGULATE CYP1A1 GENE EXPRESSION

  • Joung, Ki-Eun;Kim, Yeo-Woon;Min, Kyung-Nan;Sheen, Yhun-Yhong
    • 한국응용약물학회:학술대회논문집
    • /
    • 한국응용약물학회 2001년도 추계학술대회 및 정기총회
    • /
    • pp.112-112
    • /
    • 2001
  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.

  • PDF

노년 비만남성의 셔츠원형 개발을 통한 실버 의류산업 활성화 기반 구축 - CLO 3D 가상착의 시스템 활용 - (Building up the foundation for the elderly apparel industry through the development on shirt sloper of elderly obese males - Applying CLO 3D program -)

  • 성옥진;김숙진
    • 복식문화연구
    • /
    • 제28권3호
    • /
    • pp.299-312
    • /
    • 2020
  • The purpose of this study is to create a shirt sloper suitable for an elderly male body shape by producing virtual models using a 3D-virtualization program, making a torso prototype using the Yuka CAD system, and employing 3D simulation to virtualize and calibrate the model. First, the following three types of obese dummies are implemented through the CLO 3D program: Type 1 exhibits body fat in the lower body; Type 2 exhibits an obese abdomen; and Type 3 displays a balanced form of obesity. Second, for the design of the shirt pattern, the waist back length (measured value+1), back armhole depth (C/10+12+3+0.5~1.5), front armhole depth (back armhole depth 0~1), front interscye (2C/10-1+0.5-0.5), armscye depth (C/10+2+3.5+ 0.5), back interscye (2C/10-1+1), front chest C (C/4+2.5+1), back chest C (C/4+2.5-1), front hem C (C/4+2.5+1(+2)), back hem C (C/4+2.5-1(+2)), cap height (AH/3-5), and biceps width (Front AH-1, Back AH-1) are calculated. Third, the virtual attachment of the shirt pattern is resolved by increasing the front and back armhole depths, and the front and rear wrinkles are improved by adding a back armhole dart. The front hem lift and lateral pull caused by the protrusion of the abdomen are amended by increasing the margin of the chest, waist C, and hip C, with the appearance improved by balanced margin distribution in the front, back, and side panels. The improved retail pattern with an increase in the front armholes C was balanced on the torso plate.

Recent Development of 5 V Cathode Materials for Lithium Rechargeable Batteries

  • Kim Hyun-Soo;Periasamy Padikkasu;Moon Seong-In
    • 전기화학회지
    • /
    • 제7권1호
    • /
    • pp.1-8
    • /
    • 2004
  • This paper deals with the recent development of high-voltage cathode materials of mono- and di- metal ions substituted spinel $LiMn_2O_4$ for lithium batteries. $LiCu_xMn_{2-x}O_4(0{\leq}x{\leq}0.5)$ shows reversible intercalation/deintercalation in two potential regions, $3.9\~43\;and\;4.8-5.0V$ and stable electrochemical cycling behavior but with low capacity. $LiNi_{0.5}Mn_{1.5}O_4$ obtained by a sol-gel process delivers a capacity of 127mAh $g^{-1}$ on the first cycle and sustains a value of 124 mAh $g^{-1}$ even after the 60th cycle. The $Li_xCr_yMn_{2-y}O_4(0{\leq}x{\leq}0.5)$ solid-solutions exhibit enhanced specific capacity, larger average voltage, and improved cycling behaviors for low Cr content. $LiCr_yMn_{2-y}O_4$ presents a reversible Li deintercalation process at 4.9V, whose capacity is proportional to the Cr content in the range of $0.25{\leq}x{\leq}0.5$ and delivers higher capacities. $LiM_yCr_{0.5-y}Mn_{1.5}O_4(M=Fe\;or\;Al)$ shows that the capacity retention is lowered compared with lithium manganate. The cumulative capacities obtainable with Al-substitutted materials are less than those with Fe-substituted materials. $LiCr_xNi_{0.5-x}Mn_{1.5}O_4(x=0.1)$ delivers a high initial capacity of 1$152mAh\;g^{-1}$ with excellent cycleability.