Phosphors for remote thermograph sensing in lower temperature ranges

1996 ◽  
Vol 32 (3) ◽  
pp. 253 ◽  
Author(s):  
A.J. Simons ◽  
I.P. McClean ◽  
R. Stevens
Keyword(s):  
Temperature Ranges ◽  
Lower Temperature

scholarly journals Creep deformation behavior during densification of ZrB2-SiBCN ceramics with ZrO2 additive

2020 ◽  
Vol 9 (5) ◽  
pp. 544-557
Author(s):  
Bo Feng ◽  
Zhenhang Wang ◽  
Yunhao Fan ◽  
Jinghua Gu ◽  
Yue Zhang
Keyword(s):  
Grain Boundary ◽  
Creep Deformation ◽  
Applied Pressure ◽  
Grain Boundary Sliding ◽  
Diffusion Creep ◽  
Atom Diffusion ◽  
Grain Boundary Mobility ◽  
Controlling Mechanism ◽  
Temperature Ranges ◽  
Lower Temperature

Abstract ZrB2-SiBCN ceramics with ZrO2 additive are hot-pressed under a constant applied pressure. The densification behavior of the composites is studied in a view of creep deformation by means of the Bernard-Granger and Guizard model. With determination of the stress exponent (n) and the apparent activation energy (Qd), the specific deformation mechanisms controlling densification are supposed. Within lower temperature ranges of 1300–1400 °C, the operative mechanism is considered to be grain boundary sliding accommodated by atom diffusion of the polymer-derived SiBCN (n = 1, Qd = 123±5 kJ/mol) and by viscous flow of the amorphous SiBCN (n = 2, Qd = 249±5 kJ/mol). At higher temperatures, the controlling mechanism transforms to lattice or intra-granular diffusion creep (n = 3–5) due to gradual consumption of the amorphous phase. It is suggested that diffusion of oxygen ions inside ZrO2 into the amorphous SiBCN decreases the viscosity, modifies the fluidity, and contributes to the grain boundary mobility.

scholarly journals Internal Friction and Dynamic Modulus in Ultra-High Temperature Ru-Nb Functional Intermetallics / Tarcie Wewnętrzne I Moduł Dynamiczny W Bardzo Wysoko Temperaturowych Funkcjonalnych Związkach Międzymetalicznych Z Układu Ru-Nb

2015 ◽  
Vol 60 (4) ◽  
pp. 3069-3072
Author(s):  
M.L. Nó ◽  
L. Dirand ◽  
A. Denquin ◽  
J. San Juan
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Martensitic Transformations ◽  
Time Dependent ◽  
Structural Defects ◽  
Complete Analysis ◽  
Internal Friction Peak ◽  
Thermally Activated ◽  
Temperature Ranges ◽  
Lower Temperature

In the present work we have studied the high-temperature shape memory alloys based on the Ru-Nb system by using two mechanical spectrometers working in temperature ranges from 200 to 1450ºC and -150 to 900ºC. We have studied internal friction peaks linked to the martensitic transformations in the range from 300 to 1200ºC. In addition, we have evidenced another internal friction peak at lower temperature than the transformations peaks, which apparently exhibits the behaviour of a thermally activated relaxation peak, but in fact is a strongly time-dependent peak. We have carefully studied this peak and discussed its microscopic origin, concluding that it is related to the interaction of some structural defects with martensite interfaces. Finally, we perform a complete analysis of the whole internal friction spectrum, taking into account the possible relationship between the time-dependent peak and the martensitic transformation behaviour.

Evaluation of CO2 Absorbent/De-Absorbent by AAO/CaO Membrane

2013 ◽  
Vol 690-693 ◽  
pp. 1856-1859
Author(s):  
Chien Chon Chen ◽  
Yen Po Wang
Keyword(s):  
Anodic Aluminum Oxide ◽  
Sol Gel ◽  
Core Shell ◽  
Anodic Aluminum ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Co2 Absorbent ◽  
Lower Temperature ◽  
The Relationship ◽  
Fuel Material

This paper discussed the fabrication of anodic aluminum oxide (AAO)/CaO core-shell membrane by anodization and sol-gel processes and evaluated the relationship between the Al2O3/CaO and CO2 by thermodynamic calculation. According to thermodynamic property that CaO can reacts with CO2 forming calcium carbonate (CaCO3) in a lower temperature ranges, CaCO3 can also be decomposed to CaO in a higher temperature ranges. Because the reversible reaction property that CaO can be a CO2 absorbent/ de-absorbent. We address that AAO based on core-shell nanotubes structure to achieve such a demand. The captured CO2 can further convert to fuel material of hydrocarbons.

scholarly journals The effects of temperature on the kinetics and stability of mesophilic and thermophilic 3-phosphoglycerate kinases

1998 ◽  
Vol 330 (3) ◽  
pp. 1087-1095 ◽  
Author(s):  
M. Theresa THOMAS ◽  
K. Robert SCOPES
Keyword(s):  
Growth Temperature ◽  
Phosphoglycerate Kinase ◽  
Theoretical Explanation ◽  
Thermophilic Bacterium ◽  
Optimum Growth ◽  
Optimum Growth Temperature ◽  
Irreversible Denaturation ◽  
Temperature Ranges ◽  
Effects Of Temperature ◽  
Lower Temperature

The effects of temperature on the kinetic parameters kcat and Km, for three isolates of the highly conserved monomeric enzyme 3-phosphoglycerate kinase (PGK), were investigated in detail using a rapid automated kinetics apparatus. PGK was purified from the thermophilic bacterium Thermoanaerobacter sp. Rt8.G4 (optimum growth temperature 68 °C), the mesophile Zymomonas mobilis (optimum growth temperature 32 °C) and a second, unidentified, soil mesophile designated unid A (optimum growth temperature 27 °C). The kinetic behaviour with temperature of each PGK preparation was distinct, despite the conserved nature of the enzyme. The kcat values increased with temperature, but not as rapidly exponentially, as might be expected from the Arrhenius equation. Maximum kcat values were at much higher temperatures than the optimum growth temperatures for the mesophiles, but for the thermophile the temperature of maximum kcat was close to its optimum growth temperature. Km values were in general nearly constant through the lower temperature ranges, but increased substantially as the optimum temperature (highest kcat) was passed. Thermal irreversible denaturation of the PGK proteins was also investigated by measuring loss of activity over time. In a dilute buffer, Arrhenius plots for denaturation were linear, and the calculated apparent energy of activation (Eact) for denaturation for the thermophilic PGK was 600 kJ·mol-1, whereas for the mesophilic enzymes the values were 200-250 kJ·mol-1. In the presence of substrates, a considerable stabilization occurred, and in the case of the Z. mobilis enzyme, the apparent Eact was increased to 480 kJ·mol-1. A theoretical explanation for these observations is presented. Comparing the kinetics data with irreversible denaturation rates determined at relevant temperatures, it was clear that kcat values reached a maximum, and then decreased with higher temperature before irreversible denaturation had any significant influence.

scholarly journals Effect of The Calcination Process On The Magnetotransport Properties in Co-Precipitation Derived La0.67Ca0.33MnO3 Ceramics

2021 ◽  
Author(s):  
Yule Li ◽  
Ping Yu ◽  
Xiaojin Wang ◽  
Fuxin Ling ◽  
Qingming Chen ◽  
...  
Keyword(s):  
Colossal Magnetoresistance ◽  
Sol Gel ◽  
Insulator Transition ◽  
Precipitation Method ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Calcination Process ◽  
Temperature Ranges ◽  
Lower Temperature ◽  
Co Precipitation

Abstract La0.67Ca0.33MnO3 (LCMO) attracts considerable attention as a quintessential example for colossal magnetoresistance (CMR), metal-insulator transition and related temperature coefficient of resistance (TCR) studies. Here, co-precipitation method was utilized to prepare the LCMO ceramics, whose magnetotransport properties as a function of calcination temperature (Tcal) and calcination time (tcal) were investigated. The magnetotransport properties of these LCMO ceramics were significantly enhanced compared with LCMO derived by sol-gel methods. The TCR of LCMO increased firstly and then decreased as the Tcal increased, whereas the metal-insulator transition temperature (TMIT) shifted towards to the lower temperature. Magnetoresistance (MR) increased as Tcal rose and reached 82.4 % at Tcal = 800 ℃. The mechanism of such magnetotransport properties with different temperature ranges was discussed. The optimal TCR of 32.3%·K-1 in LCMO was prepared with Tcal = 500 ℃ and tcal = 8 h, showing that co-precipitation method would facilitate the potential application of LCMO in infrared detecting and magnetoresistive switching.

scholarly journals NOVEL POLYMER NANOCOMPOSITES FOR MICROELECTRONICS APPLICATIONS

2020 ◽  
Vol 5 (2) ◽  
pp. 315-318
Author(s):  
Pankaj Kumar Mishra
Keyword(s):  
Carrier Mobility ◽  
Peak Position ◽  
Polarization Method ◽  
Heating Rates ◽  
Depolarization Current ◽  
Electrical Fields ◽  
Temperature Ranges ◽  
Lower Temperature ◽  
Constant Heating ◽  
Thermally Stimulated Depolarization

The effect of polarization time on the space charge relaxation behavior of pure and nano ZnO doped PVK samples has been studied. The study has been carried out by thermally stimulated depolarization current patterns of electrets formed by polarization method at 350 volts field strengths at 40◦C to 70◦C with constant heating rates. The results obtained show the shift of the TSD peak position towards lower temperature ranges. Decrease in activation energy was observed corresponding to the increase in polarizing field. The intensity of the peak maxima results in being a good indicator of the trapped carrier number evolution. For high temperatures and high electrical fields the saturation of the phenomenon is achieved faster, which is attributed to facilitated carrier mobility.

scholarly journals Experimental Assessment of Water Hammer-Induced Column Separation in Oil-Hydraulic Pipe Flow

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Marcus Jansson ◽  
Magnus Andersson ◽  
Maria Pettersson ◽  
Matts Karlsson
Keyword(s):  
Cavitation Erosion ◽  
Water Hammer ◽  
Hydraulic Test ◽  
Delay Reduction ◽  
Simulation Tools ◽  
Column Separation ◽  
Temperature Ranges ◽  
Good Repeatability ◽  
Lower Temperature ◽  
Future Work

Cavitation erosion through water hammer and column separation is a major concern in hydraulic applications such as percussive rock drilling. Cavitation aspects must be considered both in early and late design stages, which require deep knowledge and tools for prediction. In this study, an oil-hydraulic test equipment for water hammer assessment was designed using state-of-the-art simulation tools. Several tests were performed, with and without column separation, showing good repeatability on measured pressures. At higher flow rates, column separation was the dominating feature and several high-pressure peaks with subsequent time delay reduction could be observed. These patterns were affected by the oil temperature, with most substantial changes at lower temperature ranges (<32 °C). Standard transmission line simulations managed to predict the water hammer, but as expected not the column separation, which is the theme of future work using this setup.

Some Aspects of the Growth of Single and Mixed Populations of Flagellates and Ciliates

1956 ◽  
Vol 33 (4) ◽  
pp. 627-644
Author(s):  
SMILJA MUČIBABIĆ
Keyword(s):  
Population Growth ◽  
Maximum Yield ◽  
Maximum Size ◽  
Multiplication Rate ◽  
Size And Shape ◽  
Different Temperatures ◽  
Temperature Ranges ◽  
Lower Temperature Range ◽  
Lower Temperature ◽  
The Relationship

Populations of Chilomonas paramecium have been maintained in a standard concentration of nutrient medium (0.1% beef-extract with 0.1% sodium acetate), at eight different temperatures, from 5 to 36° C. The temperatures 5 and 36° C. did not support the growth of a population. The rate of population growth increased with increase of temperature up to a maximum, and then decreased. The maximum yield, on the other hand, was not affected, within wide limits, by different temperatures. The relationship between temperature and maximum size of population was different when maximum size was expressed in total number of organisms from that when maximum size was expressed in terms of total volume of organisms. In the former case, the maximum size increased with the increase of temperature; while in the latter it decreased with increase of temperature. Bělehrádek's temperature coefficient, b, of the multiplication rate of Chilomonas did not show significant differences for different temperature ranges, while the coefficients Q10, and the thermal increment µ were larger for the lower temperature range. The size and shape of Chilomonas were found to depend on the temperature and on the age of the population. With increase in temperature, the size of organisms decreased to a minimum and then increased again, so that organisms were largest at extreme temperatures. In general, the organisms were more slender at lower than at higher temperatures. At all temperatures, the flagellate increased in size at the beginning of population growth and later decreased. Variation in size and shape was greatest at the beginning of growth and during transition to the maximum stationary phase.

scholarly journals Dynamics of collembolan communities inside the forested scree slope

2018 ◽  
Vol 1 ◽  
Author(s):  
Michal Rendoš ◽  
Ľubomír Kováč ◽  
Andrej Mock ◽  
Dana Miklisová
Keyword(s):  
Thermal Conditions ◽  
Karst Area ◽  
Locomotory Activity ◽  
Long Period ◽  
Monthly Temperature ◽  
Data Loggers ◽  
Collembolan Species ◽  
Temperature Ranges ◽  
Plastic Cylinder ◽  
Lower Temperature

The monthly dynamics of collembolan communities was studied over a year-long period in the depth profile of forested scree slope in the karst area of the Čierna hora Mts. (Western Carpathians, Slovakia). Collembola were sampled using non-baited subterranean traps consisted of a plastic cylinder with the small openings drilled around at 10 horizontal levels (5 – 95 cm), and a system of 10 plastic cups connected to each other by a helical rod and nuts. The plastic cylinder, after being buried in the slope profile, served as a protective casing for inserting the plastic cups filled with the preservative solution. The cups inside the cylinder were placed right under the openings on the cylinder perimeter, enabling to trap specimens in the particular depth. The temperature was measured continuously throughout the study at four-hour intervals using thermo-data loggers affixed to the wall of the plastic cups. During the year, the monthly temperature means on the surface ranged between 0.2°C (January) to 16.6°C (August) while the monthly temperature means at the depth of 95 cm ranged between 3.5°C (April) to 15.2°C (September). Monthly temperature ranges varied from 5.0°C (February) to 12.5 °C (October) on the surface and from 0.5°C (February, April) to 4.5 °C (July) at 95 cm. A total of 60 collembolan species were identified, among them 27 trogloxenes, 19 subtroglophiles, 12 eutroglophiles and 2 troglobionts. Fluctuations of the locomotory activity during the year were observed in all four categories of Collembola and at all depths. Redundancy analysis (RDA) revealed collembolan activity to be substantially affected by the thermal conditions fluctuating over the year. Most eutroglophiles and troglobionts, associated with deeper layers of the scree slope, preferred rather lower temperature ranges and were typical of the autumn months.

scholarly journals Data analysis of COVID-19 wave peaks in relation to latitude and temperature for multiple nations

2021 ◽  
Author(s):  
Mayuri Jain ◽  
Sukhada Aloni ◽  
Pravin Adivarekar
Keyword(s):  
Data Analysis ◽  
Temperature Variation ◽  
Current Data ◽  
Effect Of Temperature ◽  
Multiple Peaks ◽  
Different Seasons ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Biological Organisms

It was observed that the multiple peaks of coronavirus disease 19 (COVID 19) appeared in different seasons in different countries. There were countries where the COVID-19 peak occurred during extremely low temperatures, such as Norway, Canada and on the other hand there were countries with high-temperature ranges such as Brazil, India, UAE. Most of the high-latitude countries received their outbreak in winter and most of the countries near the equator mark the outbreak during the summer. Most of the biological organisms have their growth dependent on the temperature, and hence we explored that if there is any relation of temperature versus COVID-19 outbreak in the particular country. It was also seen that people are not behaving differently during the peak of the COVID-19 wave, hence it was important to know whether the COVID-19 virus has evolved or the global temperature variation caused these multiple peaks. This work focuses on finding the effect of temperature variation on the COVID-19 outbreak. We used Levenberg Marquardt technique to find the correlation between the temperature at which COVID-19 outbreak peaks and the latitude of the particular country. We found that between the temperature range of 14 Degree C to 20 Degree C spread of the COVID-19 is minimal. Based on our results we can also say that the COVID-19 outbreak is seen in lower temperature (0 Degree C to 13 Degree C) ranges as well as in the higher temperature ranges (21 Degree C to 35 Degree C). The current data analysis will help the authorities to manage their resources in advance to prepare for any further outbreaks that might occur in the COVID-19 or even in the next pandemic.

Sign in / Sign up

Export Citation Format

Share Document