Conductivity dynamics of metallic-to-insulator transition near room temperature in normal spinel CoFe2O4 nanoparticles

2018 ◽  
Vol 6 (17) ◽  
pp. 4720-4726 ◽  
Author(s):  
Janio Venturini ◽  
Rubia Y. S. Zampiva ◽  
Diógenes H. Piva ◽  
Roger H. Piva ◽  
João Batista M. da Cunha ◽  
...  
Keyword(s):  
Room Temperature ◽  
Site Occupancy ◽  
Insulator Transition ◽  
Effect Of Temperature ◽  
Electrical Characteristics ◽  
Cofe2o4 Nanoparticles ◽  
Normal Spinel

Designing a ferrite with dual electrical characteristics: the effect of temperature and site occupancy on the conductivity mechanisms of spinel CoFe2O4.

scholarly journals Effect of Temperature on The Electron Concentration of Crystalline GaAs Semiconductor Based on The p-n Junction Due to Deformation Potential Scattering

2019 ◽  
Vol 2 (1) ◽  
pp. 35
Author(s):  
Nova Alviati ◽  
Samsiatun Hoiriyah ◽  
Misto Misto ◽  
Edy Supriyanto
Keyword(s):  
Electron Mobility ◽  
Room Temperature ◽  
Potential Scattering ◽  
Charge Carriers ◽  
Semiconductor Materials ◽  
Effect Of Temperature ◽  
Deformation Potential ◽  
Electrical Characteristics ◽  
Gaas Crystal ◽  
Free Electrons

The electrical characteristics of semiconductor materials can be predicted based on the transport of charge carriers within the material. Under room temperature, the electrical properties of semiconductor materials can be exploited by knowing the value of their electron mobility to predict the number of electrons that experience the transport mechanism. When the material is observed under room temperature, the interaction of electrons and the lattice atoms' vibrations result in deformation potential scattering. This can stimulate electron mobility changes, which can affect the number of free electrons in semiconductor materials. The research results presented in this paper simulate the number of electrons that change due to electrons' mobility in the GaAs crystal. This material undergoes potential scattering deformation due to the interaction between electrons and phonons at temperature (40-100) K. The simulation is carried out by modeling the GaAs semiconductor material in the form of a p-n junction. The temperature variation given to the material shows a significant change in concentration in the junction area. In contrast, in the contact area's vicinity with the external circuit, both the p-layer and the n-layer show relatively constant electron concentrations.

Effect of Temperature on ADP-Induced Platelet Aggregation

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Incubation Period ◽  
Room Temperature ◽  
Important Variable ◽  
Practical Significance ◽  
Effect Of Temperature ◽  
Induce Platelet Aggregation ◽  
Cuvette Holder ◽  
Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

scholarly journals Green Biosynthesis of Silver Nanoparticles Using Leaf Extract of Carissa carandas L. and Their Antioxidant and Antimicrobial Activity against Human Pathogenic Bacteria

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 299
Author(s):  
Reetika Singh ◽  
Christophe Hano ◽  
Gopal Nath ◽  
Bechan Sharma
Keyword(s):  
Silver Nanoparticles ◽  
Pathogenic Bacteria ◽  
Leaf Extract ◽  
Room Temperature ◽  
Xrd Analysis ◽  
Antibacterial Activities ◽  
Effect Of Temperature ◽  
Human Pathogenic Bacteria ◽  
Carissa Carandas ◽  
Antioxidant And Antimicrobial Activity

Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxidant phytochemicals. Here, we expand this traditional usage with the green biosynthesis of silver nanoparticles (AgNPs) achieved using a Carissa carandas L. leaf extract as a reducing and capping agent. The green synthesis of AgNPs reaction was carried out using 1mM silver nitrate and leaf extract. The effect of temperature on the synthesis of AgNPs was examined using room temperature (25 °C) and 60 °C. The silver nanoparticles were formed in one hour by stirring at room temperature. In this case, a yellowish brown colour was developed. The successful formation of silver nanoparticles was confirmed by UV–Vis, Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The characteristic peaks of the UV-vis spectrum and XRD confirmed the synthesis of AgNPs. The biosynthesised AgNPs showed potential antioxidant activity through DPPH assay. These AgNPs also exhibited potential antibacterial activity against human pathogenic bacteria. The results were compared with the antioxidant and antibacterial activities of the plant extract, and clearly suggest that the green biosynthesized AgNPs can constitute an effective antioxidant and antibacterial agent.

scholarly journals The effect of temperature on the forward bias electrical characteristics of both pure Ni and oxidized Ni/Au Schottky contacts on n-type GaN: A case study

2020 ◽  
Vol 19 ◽  
pp. 103656
Author(s):  
Ali Hajjiah ◽  
Asmaa Alkhabbaz ◽  
Hussein Badran ◽  
Ivan Gordon
Keyword(s):  
Forward Bias ◽  
Schottky Contacts ◽  
Effect Of Temperature ◽  
Electrical Characteristics

scholarly journals The Deformation Behavior and Bending Emissions of ZnO Microwire Affected by Deformation-Induced Defects and Thermal Tunneling Effect

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5887
Author(s):  
Linlin Shi ◽  
Hong Wang ◽  
Xiaohui Ma ◽  
Yunpeng Wang ◽  
Fei Wang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Luminescent Properties ◽  
Tunneling Effect ◽  
Light Sources ◽  
Electrical Characteristics ◽  
Fundamental Research ◽  
Induced Defects ◽  
Theoretical Simulations ◽  
Bright Emission

The realization of electrically pumped emitters at micro and nanoscale, especially with flexibility or special shapes is still a goal for prospective fundamental research and application. Herein, zinc oxide (ZnO) microwires were produced to investigate the luminescent properties affected by stress. To exploit the initial stress, room temperature in situ elastic bending stress was applied on the microwires by squeezing between the two approaching electrodes. A novel unrecoverable deformation phenomenon was observed by applying a large enough voltage, resulting in the formation of additional defects at bent regions. The electrical characteristics of the microwire changed with the applied bending deformation due to the introduction of defects by stress. When the injection current exceeded certain values, bright emission was observed at bent regions, ZnO microwires showed illumination at the bent region priority to straight region. The bent emission can be attributed to the effect of thermal tunneling electroluminescence appeared primarily at bent regions. The physical mechanism of the observed thermoluminescence phenomena was analyzed using theoretical simulations. The realization of electrically induced deformation and the related bending emissions in single microwires shows the possibility to fabricate special-shaped light sources and offer a method to develop photoelectronic devices.

Effect of Temperature on the Interfacial Bonding Strength between PVB and Glass from RT to -50 °C

2011 ◽  
Vol 492 ◽  
pp. 61-65 ◽  
Author(s):  
Yuan Tian ◽  
Yi Wang Bao ◽  
De Tian Wan ◽  
Xiu Fang Wang ◽  
Zhi Ming Han
Keyword(s):  
Bonding Strength ◽  
Room Temperature ◽  
Testing Temperature ◽  
Interfacial Bonding ◽  
Effect Of Temperature ◽  
Laminated Glass ◽  
Interfacial Bonding Strength ◽  
Cooling Speed ◽  
Bonding Method ◽  
Shear Bonding Strength

Laminated glass and photovoltaic laminated glass are widely used in architecture. The interfacial bonding strengths between poly(vinyl butyral) (PVB) and glass were investigated by the cross-bonding method from room temperature to -50 °C. The loading speed was 5 mm/min, and the cooling speed was about 0.5 °C/min. The testing sample was hold at each temperature for half an hour. It was revealed that the testing temperature had great effect on the bonding strength. At room temperature, the tensile bonding strength was 11.49 MPa and the shear bonding strength was 6.61 MPa. With the temperature decreased from RT to -50 °C, the tensile bonding strength was decreased by 66.81%, but the shear bonding strength was increased by 212.16%. From RT to -30 °C, the change rates of the tensile and shear bonding strength bonding strength were 65.57% and 172.68% respectively, only 3.61% and 14.48% from -30 °C to -50 °C. The mechanism for the bonding strength depended on testing temperatures from RT to -50 °C was also discussed.

Effect of temperature and scarification on germination and emergence of wild safflower, Carthamus oxyacantha Bieb.

1975 ◽  
Vol 84 (2) ◽  
pp. 239-243 ◽  
Author(s):  
A. Bassiri ◽  
I. Rouhani ◽  
S. R. Ghorashy
Keyword(s):  
Seedling Growth ◽  
Room Temperature ◽  
Laboratory Experiments ◽  
Germination Percentage ◽  
Effect Of Temperature ◽  
Silty Clay ◽  
Wild Type ◽  
Different Temperatures ◽  
Wild Safflower ◽  
Wild Seed

SUMMARYSeeds of wild safflower, Carthamus oxyacantha Bieb., collected from the Bajgah area, Iran, were subjected to chilling and/or scarification and their germination and emergence characteristics and seedling growth were studied in two laboratory experiments. Seeds of Arak 2811 variety of cultivated safflower, C. tinctorius L., harvested from the same area at the same time was used for comparison.In the first experiment, the untreated, scarified, chilled at 0 °C for 1 month, and chilled and scarified wild seed and seed of the variety Arak 2811 were incubated at six different temperatures (5, 10, 15, 20, 25 and 30 °C) and their germination percentage and seedling lengths were recorded. In the second experiment, the seeds of the above five treatments were planted in a silty clay loam at room temperature (23 ± 2 °C) and their emergence and seedling heights were noted.In all cases, the cultivated variety, Arak 2811, had higher germination and emergence percentages and seedling heights than the wild type. Germination of both strains was greatly reduced at the two extreme temperatures (5 and 30 °C). The optimum temperatures for germination of the wild and the cultivated strains were between 15 and 20 °C.Scarification of the wild seed did not improve the germination or emergence percentages and chilling of the seed for a month at 0 °C reduced the emergence of the wild seed. Temperature of germination, however, seemed to be an important factor affecting germination and seedling growth of wild safflower.

Effect of Temperature on Incubation Time for Spontaneous Morphology Change in Electrodeposited Copper Metallization

2005 ◽  
Vol 863 ◽  
Author(s):  
S. Ahmed ◽  
D.N. Buckley ◽  
S. Nakahara ◽  
Y. Kuo
Keyword(s):  
Incubation Period ◽  
Incubation Time ◽  
Annealing Time ◽  
Room Temperature ◽  
Diffusion Mechanism ◽  
Systematic Investigation ◽  
Effect Of Temperature ◽  
Copper Metallization ◽  
Morphology Change ◽  
A Value

AbstractA systematic investigation of the effect of annealing time and temperature on the incubation period for spontaneous morphology change (SMC) in electrodeposited copper metallization is reported. The incubation time is greatly reduced at higher temperatures. At each temperature, the remaining incubation time at room temperature was found to decrease approximately linearly with increasing annealing time. An Arhennius plot of the measured rates of decrease showed good linearity and yielded a value of 0.48 eV for the activation energy. This is consistent with a vacancy diffusion mechanism for the process occurring during the incubation period and supports our proposed mechanism for SMC.

NQR Relaxation Studies on Halogenomethyl Groups in Halogenoacetates

1998 ◽  
Vol 53 (6-7) ◽  
pp. 480-483 ◽  
Author(s):  
Maria Zdanowska-Fnjczek
Keyword(s):  
Room Temperature ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Effect Of Temperature ◽  
Relaxation Theory ◽  
Temperature Range ◽  
Spin Lattice ◽  
Relaxation Studies

Abstract The effect of temperature on the chlorine NQR spin-lattice relaxation times in CsH(ClH2-CCOO)2 , KH(Cl3 CCOO) 2 and N(CH3)4 H(ClF2CCOO)2 has been studied in the temperature range 77 K to room temperature. The results were discussed on the basis of NQR relaxation theory.

Effect of temperature on plasma renin samples.

1978 ◽  
Vol 24 (7) ◽  
pp. 1202-1204 ◽  
Author(s):  
F Fyhrquist ◽  
L Puutula
Keyword(s):  
Plasma Renin Activity ◽  
Room Temperature ◽  
Plasma Renin ◽  
Renin Activity ◽  
Effect Of Temperature ◽  
Plasma Samples ◽  
Hypertensive Patients ◽  
Variable Extent ◽  
Venous Plasma

Abstract Plasma renin activity was measured in parallel in Na2EDTA-contained plasma samples after storage at -20, 4, and 24 degrees C, and in the lyophilized state. In peripheral venous plasma from 22 hypertensive patients, the activity (range, 0.08-46.7 microgram/liter per hour) remained stable during three days of storage at 4 degrees C, but decreased to a variable extent when plasma was kept at 24 degrees C: in one day by 9.2%, two days by 25.6%, and three days by 74.0%. Values were the same for samples handled at room temperature and chilled to 4 degrees C within 3 h and parallel samples immediately cooled in an icebath and kept at 4 degrees C. Freezing (-20 degrees C) and thawing of plasma was associated with a 22% mean increase in activity (range, 0-83%). Lyophilization resulted in a smaller increase of plasma renin activity (mean 12%, range 0-46%). Blood for renin analysis need not be cooled immediately, but must be cooled to 4 degrees C within 2-3 h. It then is stabe for at least three days. Freezing or lyophilization appears to be associated with some cold activation of "prorenin."

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