• Title/Summary/Keyword: EDs

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Survey on microcalorimetry about EDS (에너지 분산형 미세열량측정에 관한 자료조사)

  • Kim, J.H.;Park, K.S.;Oh, C.S.
    • Journal of Energy Engineering
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    • v.23 no.1
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    • pp.1-6
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    • 2014
  • We have surveyed on microcalorimetry which we can treat with energy dispersive spectrometer(EDS) as wavelength dispersive spectrometer(WDS), to be developed in order to make higher energy resolution as to detect X-ray peak as high as wavelength dispersive spectrometer(WDS). When we take into consideration about energy resolution, Wavelength dispersive spectrometer is 2~20eV and energy dispersive spectrometer is 140~180eV.

Enhanced Electrochemical Properties of Surface Modified LiMn2O4 by Li-Fe Composites for Rechargeable Lithium Ion Batteries

  • Shi, Jin-Yi;Yi, Cheol-Woo;Liang, Lianhua;Kim, Keon
    • Bulletin of the Korean Chemical Society
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    • v.31 no.2
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    • pp.309-314
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    • 2010
  • The surface modified $LiMn_2O_4$ materials with Li-Fe composites were prepared by a sol-gel method to improve the electrochemical performance of $LiMn_2O_4$ and were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and transmission electron microscopy (TEM)-EDS. XRD results indicate that all the samples (modified and pristine samples) have cubic spinel structures, and XRD, XPS, and TEM-EDS data reveal the formation of $Li(Li_xFe_xMn_{2-2x})O_4$ solid solution on the surface of particles. For the electrochemical properties, the modified material demonstrated dramatically enhanced reversibility and stability even at elevated temperature. These improvements are attributed to the formation of the solid solution, and thus-formed solid solution phase on the surface of $LiMn_2O_4$ particle reduces the dissolution of Mn ion and suppresses the Jahn-Teller effect.

Sleep-Wake Disturbance in Post-stroke Patients (뇌졸중 후 수면-각성장애)

  • Suh, Min-Hee;ChoiKwon, Smi
    • Journal of Korean Biological Nursing Science
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    • v.11 no.1
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    • pp.23-31
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    • 2009
  • Purpose: The purpose of the present study was to investigate the prevalence and related factors of sleep-wake disturbance (SWD) in Korean post-stroke patients. This study was the first to address post-stroke SWD in Korea using a structured questionnaire. Method: We investigated the prevalence of SWD and related factors including lesion location, stroke severity, presence of depression and fatigue. We assessed sleep-wake pattern including quality of sleep, sleep latency, wake episodes, wake time after sleep onset, daytime sleep episode and sleep time at daytime. Ninety stroke patients admitted to a university affiliated hospital in Seoul between the period September 2008 and January 2009 were included in the study. Result: Thirty five patients (38.9%) complained insomnia and 32 (35.6%) complained excessive daytime sleepiness (EDS). Quality of sleep (p=.000), sleep latency (p=.000) and total sleep time (p=.001) were significantly poorer in 16 patients with both insomnia and EDS than in the others. The related factors to insomnia were level of education (p=.030), depression (p=.007) and fatigue (p=.034), though related factors to EDS were stroke onset time (p=.049), stroke severity (p=.005), motor dysfunction (p=.035), dysphasia (p=.018), fatigue (p=.001) and lesion location (p=.019). Conclusion: Sleep-wake disturbance is a common problem in Korean stroke patients. Strategies to improve quality of sleep are urgently needed in the post-stroke patients.

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Mechanical Properties of Electro-Discharge-Sintered Porous Titanium Implants (전기방전소결에 의해 제조된 다공성 Titanium 임플란트의 기계적 특성)

  • Hyun, C.Y.;Huh, J.K.;Lee, W.H.
    • Korean Journal of Materials Research
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    • v.16 no.3
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    • pp.173-177
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    • 2006
  • Porous surfaced Ti implant compacts were fabricated by electro-discharging-sintering (EDS) of atomized spherical Ti powders. Powders of $50-100{\mu}m$ in diameter were vibratarily settled into a quarts tube and subject to a high voltage and high density current pulse in Ar atmosphere. Single pulse of 0.7 to 2.0 kJ/0.7 gpowder, from 150, 300, and $450{\mu}F$ capacitors was applied in less than $400{\mu}sec$ to produce twelve different porous-surfaced Ti implant compacts. The solid core formed in the center of the compact shows similar microstructure of cp Ti which was annealed and quenched in water. Hardness value at the solid core was much higher than that at the particle interface and particles in the porous layer, which can be attributed to both heat treatment and work hardening effects induced by EDS. Compression tests were made to evaluate the mechanical properties of the EDS compacts. The compressive yield strength was in a range of 12 to 304MPa which significantly depends on input energy. Selected porous-surfaced Ti-6Al-4V dental implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered Ti dental implants fabricated by conventional sintering process.

Tire Industry and Its Manufacturing Configuration

  • Lee, Young-Sik;Cpim;Lee, Jin-Kyu
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.04a
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    • pp.135-138
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    • 2000
  • This paper is intended to propose what manufacturing configuration (manufacturing planning and shop floor control) is suitable for the tire industry. Basically tire-manufacturing process is mixed-products, parallel-disconnected-flow-shop. Both throughput time and cycle tine are very short, the variety of tires is very high, the setup time is long, shop floor data reporting requirements is high, and there are many equipments and people working. And with no exception, tire industry also now confronts increasing requirements of delivery conformance with the above peculiar characteristics of tire manufacturing and changing market environments, this paper suggests, weekly master scheduling with no MRP is desirable and traditional kanban is right selection for shop floor control/scheduling. This paper describes why this configuration should be, using the manufacturing engineering principles and some new insights like four primitives of parallel flow shop. Generally known that shop with high parallel-product-mix and long setup time isn't good candidate for kanban. The four primitives of parallel flow shop explain why kanban is also useful scheduling technique in that environment.

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The Effects of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) on Proliferation of MCF-7 and Hec-1B Cell Lines

  • Ryu, Y.H.;Seo, D.S.;Ko, Y.
    • Proceedings of the KSAR Conference
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    • 2003.06a
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    • pp.94-94
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    • 2003
  • Endocrine disrupters (EDs) are exogenous chemicals that interfere with the production, releasing, metabolism, excretion, binding of natural hormones, and whole endocrine systems. EDs are very dangerous since they are extremely stable, not easily degraded, and accumulated in fat and tissue. 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) is known as the most toxic EDs. Therefore, this study was conducted to investigate the effects of TCDD on proliferation of human breast cancer (MCF-7) and endometrial adenocarcinoma (Hec-1B) cells. 10, 100, and 1000 nM of TCDD were treated with steroid free condition. Viable cell counting, MTT, and BrdU assay was performed to investigate cell proliferation. Apoptosis was investigated using DNA laddering. Although, DNA fragmentation as the evidence of apoptosis was not detected, all of these cell lines showed restricted proliferation at 48 hrs after 100 and 1000 nM TCDD treatments. Recently, it has been reported that the expression of transforming growth factor $\beta$s (TGF-$\beta$s) are increased in TCDD treatment and also involved in regulation of cell cycle. Therefore, these results were considered that the decreased cell prolifcration by TCDD is related to the expression of TGF-$\beta$s.

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How to Understand Sleep and Sleep Problems in Patients with Prader-Willi Syndrome?

  • Joo, Eun Yeon
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.1 no.2
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    • pp.35-39
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    • 2015
  • Sleep problems occur frequently among patients with Prader-Willi syndrome (PWS). The most common problem is excessive daytime sleepiness (EDS) that are closely related to of sleep-related breathing disorder (SRBD) such as obstructive sleep apnea (OSA) and congenital hypoventilation syndrome. Obesity, craniofacial dysmorphism and muscular hypotonia of patients with PWS may increase the risk of SRBD. Sleep apneas can interrupt the continuity of sleep, and these disruptions result in a decrease in both the quality and quantity of sleep. In addition to SRBD, other sleep disorders have been reported, such as hypersomnia, a primary abnormality of the rapid eye movement (REM) sleep and narcolepsy traits at sleep onset REM sleep. Patients with PWS have intrinsic abnormalities of sleep-wake cycles due to hypothalamic dysfunction. The treatment of EDS and other sleep disorders in PWS are similar to standard treatments. Correction of sleep hygiene such as sufficient amount of sleep, maintenance of regular sleep-wake rhythm, and planned naps are important. After comprehensive evaluation of sleep disturbances, CPAP or surgery should be recommended for treatment of SRBD. Remaining EDS or narcolepsy-like syndrome are controlled by stimulant medication. Bright light therapy might be beneficial for disturbed circadian sleep-wake rhythm caused by hypothalamic dysfunction.

Study of the Stability of Brass Coated on Steel Cords with pH and Applied Constant Potential Changes in Aqueous Solutions by AC Impedance Measurements (교류임피던스 측정에 의한 수용액에서 pH와 일정공급전위 변화에 따른 강철심에 도금된 놋쇠의 안정성 연구)

  • Ko, Young Chun;Chung, Keun Ho
    • Analytical Science and Technology
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    • v.8 no.3
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    • pp.293-298
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    • 1995
  • The stability of brass coated on steel cords with pH and applied constant potential changes in aqueous solution has been investigated by AC impedance measurements. In solutions of the constant pH, as a applied constant potential is shifted to positive potential, the coating pore resistance is reduced. The fact indicates that as a applied constant potential is shifted to positive potential, the brass coated is dissolved more in solution. The stability of brass coated on steel cords decrease in the order pH=7.1 > pH=4.0 > pH=10.0. The above results are demonstrated by the data of scanning of electronic microscopy(SEM)/energy dispersive spectrometer(EDS).

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Fusiform Aneurysm Presenting with Cervical Radiculopathy in Ehlers-Danlos Syndrome

  • Kim, Ho-Sang;Choi, Chang-Hwa;Lee, Tae-Hong;Kim, Sang-Phil
    • Journal of Korean Neurosurgical Society
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    • v.48 no.6
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    • pp.528-531
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    • 2010
  • Ehlers-Danlos syndrome (EDS) type IV is characterized by its clinical manifestations, which are easy bruising, thin skin with visible veins, and rupture of arteries, uterus, or intestines. Arterial complications are the leading cause of death in vascular EDS because they are unpredictable and surgical repair is difficult due to tissue fragility. The authors report a case presented with cervical radiculopathy due to a segmental fusiform aneurysm of the cervical vertebral artery. Transfemoral cerebral angiography (TFCA) was done to verify the aneurysmal dilatation. However, during TFCA, bleeding at the puncture site was not controlled, skin and underlying muscle was disrupted and profound bleeding occurred during manual compression after femoral catheter removal. Accordingly, surgical repair of the injured femoral artery was performed. At this time it was possible to diagnose it as an EDS with fusiform aneurysm on cervical vertebral artery. Particularly, cervical fusiform aneurysm is rare condition, and therefore, connective tissue disorder must be considered in such cases. If connective tissue disorder is suspected, the authors suggest that a noninvasive imaging modality, such as, high quality computed tomography angiography, be used to evaluate the vascular lesion to avoid potential arterial complications.

Airport Power Information System Design in the Inchon Inta'l Airport (인천국제공항 공항전력정보시스템 설계)

  • Oh, Y.D.;Min, S.J.;Lim, J.G.;Moon, J.H.;Lee, T.S.;Yun, T.H.;Kim, M.H.;Moon, Y.H.
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1121-1124
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    • 1998
  • Inchon International Airport(IIA) is constructed for Northeast Asia Gate as is important for IIA to become a 21 century's leader in the world, as is planned for open at december 2000 as a important economic link for unified korea. Airport Power Information System(APIS) is designed through investigation of advanced domestic and international example. In addition to power facility operation it is designed for using an information infrastructure of whole airport. APIS is newly designed for uninterupted power supply, effective power management, information infrastructure's construction. making a profit by positively introduction of new technology for collection and conservation of power related data, correlation with airport infra systems, data interrelative arrangement about related systems like outdoor lighting system and automatic measuring record, CCTV systems for remote power facility monitoring, and promotion of management ability in the emergency status.

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