• The Korean Journal of Physiology
• /
• v.23 no.2
• /
• pp.225-236
• /
• 1989

1) At the isolated perfused guinea-pig and rat heart heterometric autoregulation of the myocardium and myogenic autoregulation of the coronary vessels were induced by means of stepwise increases of perfusion pressure. 2) According to this loading test Frank-Starling function curves of the left ventricle and pressure-flow curves of the coronary vessels can be drawn. This graphic evaluation gives more information about the condition of the heart and the coronary vessels than simple evaluation under hemodynamic equilibrium. 3) There are significant differences in both curves between animal species and between different perfusate Mg concentration. 4) Myogenic autoregulation is not affected by the cyclooxygenase inhibitors indometacin and me- clofenamate. Thus it appears unlikely that prostanoides are involved in myogenic autoregulation. 5) Ca antagonists (Gallopamil, prenylamine) depress myogenic autoregulation dose-dependently. Enhanced myogenic autoregulation, induced by low extracellular magnesium, can be reduced effectively by Gallopamil. 6) Ginsenosides from Panax ginseng as well as the ginsenoside 'Rg' are effective inhibitors of myogenic autoregulation without major negative inotropic effects.

• YAKHAK HOEJI
• /
• v.23 no.3_4
• /
• pp.129-132
• /
• 1979

The ORD and CD for hyoscine-N-butylbromide present curves of negative Cotton effect in 190-250nm region. The values of .alpha./sub 232/ .alpha./sub 208/, vertical bar .alpha./sub 232/ vertical bar + vertical bar .alpha./sub 208/ and .theta./sub 221.5/ have linearities in the range of lower concentration (hyoscine-N-butylbromide 0.01-0.1w/v%). It is possible to determine the optical purity of hyoseine-N-butylbromide by using these linearities. This experiment is extremely simple and less time-consuming than other methods for estimating optical purity.

• 전기의세계
• /
• v.20 no.2
• /
• pp.27-31
• /
• 1971

Using insulating paper (cellophan), we measured the influences of moisture abosrbed for electrical properties i.e. V.I curves which result in deteriorating due to the moisture alsorbed is related to electrical properties Considerally due to the electrolytic effects of moisture involved cellulose Gel structure, we obtained also an evaluation method of deterioration rate Caused by the moisture absorbed in insulating papers.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.02a
• /
• pp.263-265
• /
• 2003

A winding machine to fabricate the double pancake coils was manufactured. A race-track type double pancake coil using high temperature superconductor (HTS) tape was prepared and I-V and I-H characteristic curves were obtained at the atmosphere of liquid nitrogen. The winding method to make the double pancake coil and its properties is discussed.

• Journal of the Korean Vacuum Society
• /
• v.10 no.2
• /
• pp.257-261
• /
• 2001

InAs/GaAs quantum dots between InGaAs/GaAs superlattices were grown by MBE. The quantum dots size is shown to be very uniform by measuring photoluminescence spectra of quantum dots. Single photon structures based on self-consistent calculation were grown and single photon devices were fabricated by e-beam lithography. The electrical hystereses of I-V curves for single Photon devices would result from single electron-hole recombination, where the resonant-tunneling voltages of electron and hole are different.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.6
• /
• pp.678-682
• /
• 2004

Generally Bi-2223/Ag tapes have a broad S/N transition region and their sheath is a good electric conductor. In this study, the current distribution between superconductor and metal sheath in HTS tapes were investigated. AC with its peak value above 10 times $I_{c}$ was applied to HTS tapes for around 6 cycles and V-I characteristics were measured. Using the resistance of the sheath and V-I curves, the current distribution between superconductor and metal sheath was calculated. When 150 $A_{p}$ was applied, more than 2/3 of the current flows through superconductor. However, in the case of 304 $A_{p}$, most of the applied current came to flow through the metal sheath at the 6th cycle.e.e.e.

• Journal of Magnetics
• /
• v.14 no.1
• /
• pp.11-14
• /
• 2009

We investigated the I-V curves and differential tunneling conductance of two, CoFeB/MgO/CoFeB-based, magnetic tunnel junctions (MTJs): one with a low tunneling magnetoresistance (TMR; 22%) and the other with a high TMR (352%). This huge TMR difference was achieved by different MgO sputter conditions rather than by different annealing or deposition temperature. In addition to the TMR difference, the junction resistances were much higher in the low-TMR MTJ than in the high-TMR MTJ. The low-TMR MTJ showed a clear parabolic behavior in the dI/dV-V curve. This high resistance and parabolic behavior were well explained by the Simmons' simple barrier model. However, the tunneling properties of the high-TMR MTJ could not be explained by this model. The characteristic tunneling properties of the high-TMR MTJ were a relatively low junction resistance, a linear relation in the I-V curve, and conduction dips in the differential tunneling conductance. We explained these features by applying the coherent tunneling model.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.1
• /
• pp.1-7
• /
• 2014

A bidirectional transient voltage suppression (TVS) diode consisting of specially designed $p^--n^{{+}+}-p^-$ multi-junctions was developed using low temperature (LT) epitaxy and fabrication processes. Its electrostatic discharge (ESD) performance was investigated using I-V, C-V, and various ESD tests including the human body model (HBM), machine model (MM) and IEC 61000-4-2 (IEC) analysis. The symmetrical structure with very sharp and uniform bidirectional multi-junctions yields good symmetrical I-V behavior over a wide range of operating temperature of 300 K-450 K and low capacitance as 6.9 pF at 1 MHz. In addition, a very thin and heavily doped $n^{{+}+}$ layer enabled I-V curves steep rise after breakdown without snapback phenomenon, then resulted in small dynamic resistance as $0.2{\Omega}$, and leakage current completely suppressed down to pA. Manufactured bidirectional TVS diodes were capable of withstanding ${\pm}4.0$ kV of MM and ${\pm}14$ kV of IEC, and exceeding ${\pm}8$ kV of HBM, while maintaining reliable I-V characteristics. Such an excellent ESD performance of low capacitance and dynamic resistance is attributed to the abruptness and very unique profiles designed very precisely in $p^--n^{{+}+}-p^-$ multi-junctions.

• Journal of Radiation Protection and Research
• /
• v.7 no.1
• /
• pp.49-55
• /
• 1982

Thermally stimulated currents of polymers have some properties as radiation dosimetry, especially polymer could be made as a good dosimeter in biological fields because of tissue equivalent material. We experimented the radiation response of polymers and attempted to apply it in clinical use. Polymers have the properties of thermoluminescence and thermally stimulated currents which are due to several kinds of charged particles such as dipoles, electronic trapped charges and mobile ions. Several peaks are datected in the thermally stimulated currents in polyethylene under vias field V, by heating from room temperature to $100^{\circ}C$ shortly after irradiation. As V increases, both the peak temperature $T_m$ and the activation energy H decreases, while the peak current $I_m$ increases. We plotted the $T_m-V\;and\;I_m-V$ curves and calculated the electron trap depth with the recombination operative TSC theory and compared the peak TSC with radiation doses.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.687-690
• /
• 2004

Fabrication and characterization of dye-sensitized TiO2 solar cells(DSSC) consisting of spray-coated TiO2 electrode, an electrolyte containing I-/I3- redox couple, and a Pt-coated counter electrode carried out, using mainly FE-SEM and solar simulator. Also, effect of rapid thermal annealing(RTA) temperatue on I-V curves of DSSCS consisting of approximately 10m thickness and $5{\times}5mm2$ active area. No significant difference in the apparent size of TiO2 clusters was observed with increasing RTA temperature. Also, an open circuit voltage(Voc) of approximately 0.70V and a short-circuit photocurrent(Jsc) of 8 to 12mA/cm2 were observed in the TiO2 solar cell. With increasing RTA temperature upto 550oC, photocurrent density of dye-sensitized solar cells was enhanced, leading to enhancing the efficiency of dye-sensitized solar cells having Pt-electroplated counter electrode.