• Title/Summary/Keyword: ER

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Electrical Resistivity and Charge Density of Bismuth Telluride Doped with Erbium

  • Yeom, Tae-Ho
    • Journal of Magnetics
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    • v.10 no.4
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    • pp.149-151
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    • 2005
  • The electric properties of a single crystal bismuth telluride doped with a small concentration of Erbium, $Bi_{z-x}Er_xTe_3$ with x = 0.002, are investigated as a function of temperature. The resistivity was obtained by using the van der Pauw method. The measured electrical resistivity is 78 ${\mu}{\Omega}cm$ at 4.2 K. The charge density of $Bi_{z-x}Er_xTe_3$ is found to be $2{\times}10^{19}/cm^3$ at 4.2 K. It turns out that $Bi_{z-x}Er_xTe_3$ is a p-type semiconductor. It is discussed that the high mobility and less density support that $Bi_{z-x}Er_xTe_3$ is a potential sensor with high energy resolution. Comparison with an established material (i.e. Au:Er alloy) is also discussed.

Effect of Er2O3 Content on Nonlinear Properties and Impulse Clamping Characteristics of Pr/Co/Cr/Al Co-doped Zinc Oxide Ceramics

  • Nahm, Choon-Woo
    • Journal of the Korean Ceramic Society
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    • v.51 no.6
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    • pp.612-617
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    • 2014
  • The microstructure, nonlinear properties, and impulse clamping characteristics of Pr/Co/Cr/Al co-doped zinc oxide ceramics were investigated with various contents of $Er_2O_3$. Increasing $Er_2O_3$ content increased the density of the sintered pellets from 5.69 to $5.83g/cm^3$, and decreased the average grain size from 10.6 to $6.5{\mu}m$. With increased $Er_2O_3$ content, the breakdown field increased from 2318 to 4205 V/cm, and the nonlinear coefficient increased from 19.4 to 40.2. The clamp characteristics were improved with the increase of the content of $Er_2O_3$. The varistors doped with 2.0 mol% exhibited the best clamp characteristics, in which the clamp voltage ratio was 1.40-1.73 at 1-50 A in an impulse current.

Influence of Sintering Temperature and Electrical Properties on ZPCCE Based Varistors (ZPCCE계 바리스터의 전기적 성질에 소결온도가 미치는 영향)

  • 류정선;윤한수;남춘우
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.242-245
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    • 2000
  • The electrical properties of ZPCCE (ZnO-Pr$_{6}$O$_{11}$-CoO-Cr$_2$O$_3$-Er$_2$O$_3$) based varistors were investigated with sintering temperature in range of 1335 to 135$0^{\circ}C$ for 1h. As the sintering temperature increases, the nonlinear exponent decreased, but was high beyond 40 except for 1.0 mol% Er$_2$O$_3$. Among all ZPCCE varistors, the varistor having the highest nonlinear exponent was obtained by sintering at 1335$^{\circ}C$, containing 2.0 mol% Er$_2$O$_3$ and then the nonlinear exponent was 78.05, and the varistors with 0.5 mol% Er$_2$O$_3$ exhibited the lowest leakage current of 1.92 $\mu$A.A.A.

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Electrorheological Effect of the Suspension Composed of Bismark Brown Chitosan Succinate as the Dispersed Phase

  • Choi, Ung-Su
    • KSTLE International Journal
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    • v.8 no.2
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    • pp.21-25
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    • 2007
  • The electrorheological effect of the suspension composed of Bismark Brown chitosan succinate as the dispersed phase in silicone oil was investigated. Bismark Brown chitosan succinate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 1.84 power on the electric field. The experimental results for the suspension correlated with the polarization model and Bismark Brown chitosan succinate suspension behaved as an anhydrous ER fluid. On the basis of the results, Bismark Brown chitosan succinate suspension showed the ER flow behavior upon application of the electric field due to the polarizability of the branched amide and amine polar groups of the Bismark brown chitosan succinate particles.

Vibration mode control of a smart plate containing electro-rheological fluid (ER유체를 이용한 스마트 평판의 진동모드 제어)

  • 정상봉;박용균;최승복
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.10a
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    • pp.451-455
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    • 1997
  • This paper presents vibration mode control of a smart plate containing electro-rheological (ER) fluid between elastic face layers. Following the composition of a silicone oil-based ER fluid, the ER fluid-embedded plate partitioned into four sections is constructed. Then, an extensive modal test is experimentally carried out to identify field-dependent modal parameters such as mode shapes and natural frequencies of the structure with respect to different are subjected to electric fields. The distilled results from the experiment exhibit that the ER fluid can be effectively employed in a continuous fashion to tune modal behaviors of the distributed parameter systems,

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Force Feedback Control of 3 DOF Haptic Device Utilizing Electrorheological Fluid (ER 유체를 이용한 3 자유도 햅틱 장치의 힘 반향 제어)

  • Han, Y.M.;Kang, P.S.;Choi, S.B.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.213-216
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    • 2005
  • This paper presents force feedback control performance of a 3DOF haptic device that can be used for minimally invasive surgery (MIS). As a first step, a 3DOF electrorheological (ER) joint is designed using a spherical mechanism. And it is optimized based on the mathematical torque modeling. Subsequently, the master haptic device is manufactured by the spherical joint. In order to achieve desired force trajectories, model based compensation strategy is adopted for the ER master. Therefore, Preisach model fur the PMA-based ER fluid is identified using experimental first order descending (FOD) curves. A compensation strategy is then formulated through the model inversion to achieve desired force at the ER master. Tracking control performances for sinusoidal force trajectory are presented, and their tracking errors are evaluated.

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Understanding the Unfolded Protein Response (UPR) Pathway: Insights into Neuropsychiatric Disorders and Therapeutic Potentials

  • Pitna Kim
    • Biomolecules & Therapeutics
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    • v.32 no.2
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    • pp.183-191
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    • 2024
  • The Unfolded Protein Response (UPR) serves as a critical cellular mechanism dedicated to maintaining protein homeostasis, primarily within the endoplasmic reticulum (ER). This pathway diligently responds to a variety of intracellular indicators of ER stress with the objective of reinstating balance by diminishing the accumulation of unfolded proteins, amplifying the ER's folding capacity, and eliminating slow-folding proteins. Prolonged ER stress and UPR irregularities have been linked to a range of neuropsychiatric disorders, including major depressive disorder, bipolar disorder, and schizophrenia. This review offers a comprehensive overview of the UPR pathway, delineating its activation mechanisms and its role in the pathophysiology of neuropsychiatric disorders. It highlights the intricate interplay within the UPR and its profound influence on brain function, synaptic perturbations, and neural developmental processes. Additionally, it explores evolving therapeutic strategies targeting the UPR within the context of these disorders, underscoring the necessity for precision and further research to effective treatments. The research findings presented in this work underscore the promising potential of UPR-focused therapeutic approaches to address the complex landscape of neuropsychiatric disorders, giving rise to optimism for improving outcomes for individuals facing these complex conditions.

EFFECTS OF DIETARY TRYPTOPHAN LEVEL AND FOOD INTAKE ON ENERGY UTILIZATION BY MALE GROWING CHICKS

  • Sugahara, K.;Kubo, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.4
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    • pp.647-651
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    • 1992
  • Two experiments involving comparative slaughter procedures were conducted to see if the decrease in total energy retention (ER) resulted from the decreased food intake in growing chicks fed on a diet containing tryptophan less than the requirement. Ad libitum-feeding a diet containing 50% of tryptophan of a control diet (1.5 g/kg) decreased body weight gain, apparent metabolizable energy intake (AMEI), ER and ER : AMEI ratio. When both the control diet and the 0.75 g/kg tryptophan diet were tube-fed at the two levels of food intake, body weight gain was significantly lower in chicks on the low tryptophan diet than in the control chicks at each level of intake. AME : gross-energy ratio decreased only when the low tryptophan diet was tube-fed at the higher level of intake. Energy retained as protein was significantly decreased by the low tryptophan level and reduction of food intake. Energy retained as fat was affected by food intake. ER and ER : AMEI ratio were unaffected by dietary tryptophan level and were proportional to AMEI. Heat increment of feeding was affected by neither tryptophan nor food intake. These results indicate that the decreased ER in chicks fed on the low tryptophan diet was due mainly to the decreased food intake and not to the decreased efficiency of ME utilization.

High-Luminous Efficiency Full-Color Emitting $GdVO_4$:Eu, Er, Tm Phosphor Thin Films

  • Minami, Takatsugu;Miyata, Toshihiro;Mochizuki, Yuu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1091-1094
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    • 2004
  • High-luminous efficiency full-color emissions in photoluminescence (PL) were obtained in $GdVO_4$ phosphor thin films co-doped with various amounts of Eu, Er and/or Tm and postannealed at approximately 1000$^{\circ}C$. The $GdVO_4$:Eu,Er,Tm phosphor thin films were deposited on thick $BaTiO_3$ ceramic sheets by r.f. magnetron sputtering using powder targets and postannealed in an air atmosphere. The rare earth (RE) content (RE/(Gd+V+RE) atomic ratio) in the oxide phosphor thin films was varied in the range from 0.1 to 2 at.%. It was found that the excitation of $GdVO_4$:Eu.Er,Tm thin films is attributed to band-to-band transition. A white PL emission was obtained in a $GdVO_4$:Eu,Er,Tm thin film with Eu, Er and Tm contents of 0.2, 0.7 and 1 at.%, respectively: CIE chromaticity color coordinates. (X=0.352 and Y=0.351). In addition, a white emission was obtained in a thin-film electroluminescent (TFEL) device made with this thin film.

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Effects of HIF-1α/VP16 Hybrid Transcription Factor on Estrogen Receptor in MCF-7 Human Breast Cancer Cells

  • Cho, Jung-Yoon;Park, Mi-Kyung;Lee, Young-Joo
    • Biomolecules & Therapeutics
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    • v.13 no.4
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    • pp.227-231
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    • 2005
  • The estrogen receptor (ER) is activated and degraded by estrogen. We have examined ER downregulation and activation under hypoxia mimetic conditions. Cobalt chloride induced ER downregulation at 24 h of treatment. This degradation involved hypoxia-inducible factor-1$\alpha$ (HIF-1$\alpha$) as examined by using a constitutively active form of HIF-1$\alpha$, HIF-1$\alpha$/VP16, constructed by replacing the transactivation domain of HIF-1$\alpha$ with that of VP16. Western blot analysis revealed that E2-induced ER downregulation was observed within ${\~}6h$, whereas HIF-1$\alpha$/VP16-induced ER degradation was observed within 12${\~}$20h. HIF-1$\alpha$/VP16 activated the transcription of estrogen-responsive reporter gene in the absence of estrogen. These results suggest that ER downregulation and activation under hypoxia maybe mediated in part by a HIP-1$\alpha$ expression.