Temperature dependence of the resistance, impedance and capacitance of semitransparent PTB7-Th and PCBM sensor

2019 ◽  
Vol 33 (12) ◽  
pp. 1950110
Author(s):  
Muhammad Riaz ◽  
Khasan S. Karimov ◽  
Jameel-Un Nabi

The temperature dependences of resistance, impedance and capacitance of semitransparent sensor having structure ITO/PTB7-Th:PC[Formula: see text]BM/Graphene composite (semisurface type) were investigated. The transparency of the sensor was 58–60%. The dependences of the resistance, impedance and capacitance at different frequencies 100 Hz, 1 kHz, 10 kHz, 100 kHz and 200 kHz and temperature in the range of 23.8–80[Formula: see text]C for the sensor were studied. It was observed that as the temperature increased from 23.8[Formula: see text]C to 80[Formula: see text]C, the resistance and impedance (at 1 kHz) of the samples decreased, on average, by a factor of 3.51 and 3.79, respectively. At same experimental conditions (1 kHz), the capacitances of the samples also decreased by a factor of 9.6. It was also noted that as frequency increased from 100 Hz to 200 kHz, the impedance of the sensor decreased by a factor of 21 and 12, at temperatures 24[Formula: see text]C and 58[Formula: see text]C, respectively. Under the same conditions, the capacitance decreased by a factor of 30 and 28, respectively. The temperature resistance coefficients were measured to be −1.31%/[Formula: see text]C, −1.30%/[Formula: see text]C, −1.27%/[Formula: see text]C, −0.84%/[Formula: see text]C, −0.72%/[Formula: see text]C and −0.33%/[Formula: see text]C for R, Z (100 Hz), Z (1 kHz), Z (10 kHz), Z (100 kHz) and Z (200 kHz), respectively. For capacitance measurement, the temperature capacitance coefficients were measured as −1.39%/[Formula: see text]C, −1.38%/[Formula: see text]C, −1.37%/[Formula: see text]C, −1.36%/[Formula: see text]C and −1.34%/[Formula: see text]C, respectively. The semitransparent PTB7-Th- and PC[Formula: see text]BM-based temperature sensor can be used for measurement of the temperature as a teaching aid in situations where visual control of illumination and light intensity is required.

Author(s):  
C. McCarthy ◽  
H. Savage ◽  
M. Nettles

Using a new biaxial friction apparatus, we conducted experiments of ice-on-rock friction in order to better understand basal sliding of glaciers and ice streams. A series of velocity-stepping and slide–hold–slide tests were conducted to measure friction and healing at temperatures between −20°C and melting. Experimental conditions in this study are comparable to subglacial temperatures, sliding rates and effective pressures of Antarctic ice streams and other glaciers, with load-point velocities ranging from 0.5 to 100 µm s −1 and normal stress σ n  = 100 kPa. In this range of conditions, temperature dependences of both steady-state friction and frictional healing are considerable. The friction increases linearly with decreasing temperature (temperature weakening) from μ  = 0.52 at −20°C to μ  = 0.02 at melting. Frictional healing increases and velocity dependence shifts from velocity-strengthening to velocity-weakening behaviour with decreasing temperature. Our results indicate that the strength and stability of glaciers and ice streams may change considerably over the range of temperatures typically found at the ice–bed interface. This article is part of the themed issue ‘Microdynamics of ice’.


2015 ◽  
Vol 8 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Zilong Wang ◽  
Hua Zhang ◽  
Wei Zhao ◽  
Zhigang Zhou ◽  
Mengxun Chen

Research on automatic tracking solar concentrator photovoltaic systems has gained increasing attention in developing the solar PV technology. A paraboloidal concentrator with secondary optic is developed for a three-junction GaInP/GalnAs/Ge solar cell. The concentration ratio of this system is 200 and the photovoltaic cell is cooled by the heat pipe. A detailed analysis on the temperature coefficient influence factors of triple-junction solar cell under different high concentrations (75X, 100X, 125X, 150X, 175X and 200X) has been conducted based on the dish-style concentration photovoltaic system. The results show that under high concentrated light intensity, the temperature coefficient of Voc of triple-junction solar cell is increasing as the concentration ratio increases, from -10.84 mV/°C @ 75X growth to -4.73mV/°C @ 200X. At low concentration, the temperature coefficient of Voc increases rapidly, and then increases slowly as the concentration ratio increases. The temperature dependence of η increased from -0.346%/°C @ 75X growth to - 0.103%/°C @ 200X and the temperature dependence of Pmm and FF increased from -0.125 W/°C, -0.35%/°C @ 75X growth to -0.048W/°C, -0.076%/°C @ 200X respectively. It indicated that the temperature coefficient of three-junction GaInP/GalnAs/Ge solar cell is better than that of crystalline silicon cell array under concentrating light intensity.


1993 ◽  
Vol 58 (2) ◽  
pp. 234-243 ◽  
Author(s):  
Viliam Klimo ◽  
Martina Bittererová ◽  
Stanislav Biskupič ◽  
Ján Urban ◽  
Miroslav Micov

The reaction O + OH → O2 + H in conditions of combustion of hydrocarbons and polymers was modelled by using the method of quasiclassical trajectories. The potential energy surface was determined by the multiconfiguration interaction method and fitted with the analytical form of the extended LEPS function. Attention was paid to the mean values of the vibrational and rotational quantum numbers of O2 molecules and their temperature dependence. The temperature dependence of the mean lifetime of the OOH collision complex was also examined. The calculated rate constants were analyzed and compared with the experimental data over the temperature region of the combustion processes.


1974 ◽  
Vol 29 (1) ◽  
pp. 145-157 ◽  
Author(s):  
Tetsuhiko Tomiki ◽  
Takeo Miyata ◽  
Hirokazu Tsukamoto

Phenomenological and physical aspects of the intrinsic tail spectra of the alkalihalides are studied referring to the new results on the intrinsic tail spectra of KBr and KI and to the temperature dependences of the lowest-energy Γ-exciton peak of the sodium- and potassium-halides. Systematically analysing the temperature dependence of the steepness parameter σs (T) of the Urbach rule for these halides, it is found that the frequency factor has the value nearly equal to the acoustic phonon energy at X or L of each host lattice and the steepness constant σs0 becomes larger in passing from fluoride to iodide. This halogen dependence of σs0 is discussed in terms of the hole band-mass of the Γ8-level.


2006 ◽  
Vol 361 (1472) ◽  
pp. 1307-1315 ◽  
Author(s):  
Lin Wang ◽  
Nina M Goodey ◽  
Stephen J Benkovic ◽  
Amnon Kohen

Residues M42 and G121 of Escherichia coli dihydrofolate reductase ( ec DHFR) are on opposite sides of the catalytic centre (15 and 19 Å away from it, respectively). Theoretical studies have suggested that these distal residues might be part of a dynamics network coupled to the reaction catalysed at the active site. The ec DHFR mutant G121V has been extensively studied and appeared to have a significant effect on rate, but only a mild effect on the nature of H-transfer. The present work examines the effect of M42W on the physical nature of the catalysed hydride transfer step. Intrinsic kinetic isotope effects (KIEs), their temperature dependence and activation parameters were studied. The findings presented here are in accordance with the environmentally coupled hydrogen tunnelling. In contrast to the wild-type (WT), fluctuations of the donor–acceptor distance were required, leading to a significant temperature dependence of KIEs and deflated intercepts. A comparison of M42W and G121V to the WT enzyme revealed that the reduced rates, the inflated primary KIEs and their temperature dependences resulted from an imperfect potential surface pre-arrangement relative to the WT enzyme. Apparently, the coupling of the enzyme's dynamics to the reaction coordinate was altered by the mutation, supporting the models in which dynamics of the whole protein is coupled to its catalysed chemistry.


1979 ◽  
Vol 44 (12) ◽  
pp. 3521-3528 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Josef Koubek ◽  
Jiří Pick

The temperature dependences of heats of vaporization of propylamine, isopropylamine, butylamine, isobutylamine, sec-butylamine, cyclohexylamine, diethylamine and triethylamine and saturated vapour pressures of butylamine, isobutylamine, sec-butylamine and triethylamine were measured. The cohesive energies of amines studied in dependence on temperature were calculated from the experimental values.


1983 ◽  
Vol 69 (4) ◽  
pp. 305-308 ◽  
Author(s):  
Franco Zunino ◽  
Renato Marchesini ◽  
Elsa Melloni ◽  
Giuseppina Savi ◽  
Gabriella Pezzoni ◽  
...  

The effectiveness of laser photoradiation therapy with hematoporphyrin derivative sensitization was tested in the MS-2 sarcoma. This solid tumor, transplanted into the pad of the hind leg of BALB/c mice, was found to be a sensitive experimental model for a quantitative evaluation of response to phototherapy and for determination of critical parameters in laser phototherapy treatment. Under our experimental conditions, optimal therapeutic effects appeared to be critically dependent on drug dose, number of treatments, light intensity, and irradiation of the peripheral border of the tumor.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hoang Tung Nguyen ◽  
Van Long Le ◽  
Thi Minh Hai Nguyen ◽  
Tae Jung Kim ◽  
Xuan Au Nguyen ◽  
...  

Abstract We report the temperature dependence of the dielectric function ε = ε1 + iε2 and critical point (CP) energies of biaxial α-SnS in the spectral energy region from 0.74 to 6.42 eV and temperatures from 27 to 350 K using spectroscopic ellipsometry. Bulk SnS was grown by temperature gradient method. Dielectric response functions were obtained using multilayer calculations to remove artifacts due to surface roughness. We observe sharpening and blue-shifting of CPs with decreasing temperature. A strong exciton effect is detected only in the armchair direction at low temperature. New CPs are observed at low temperature that cannot be detected at room temperature. The temperature dependences of the CP energies were determined by fitting the data to the phenomenological expression that contains the Bose–Einstein statistical factor and the temperature coefficient for describing the electron–phonon interaction.


1982 ◽  
Vol 114 (4) ◽  
pp. 377-379 ◽  
Author(s):  
Bernard J. R. Philogène

The use of artificial illumination in entomological studies is extensive. Incandescent and fluorescent lights are used in mass-rearing insects necessary for physiological and ecological studies, and in photoperiod-controlled as well as in electrophysiological experiments.One of the main problems facing investigators in the interpretation of their results or in comparing these to preceding reports is the plethora of ways in which experimental conditions involving light are reported. Here are some examples: “The ants were kept under fluorescent light from 0800 to 2000 hours; light intensity on the ants was about 400 lux” (McCluskey 1965).


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