Pseudo-Plastic Phenomena with Vulcanized Rubber

1944 ◽  
Vol 17 (4) ◽  
pp. 854-864 ◽  
Author(s):  
A. J. Wildschut
Keyword(s):  
Natural Rubber ◽  
Room Temperature ◽  
Total Flow ◽  
Total Rate ◽  
Considerable Part ◽  
Vulcanized Rubber ◽  
Constant Tension ◽  
Different Temperatures ◽  
Flow Diagrams ◽  
Increasing Temperature

Abstract It is shown that plastic flow and relaxation of vulcanized natural rubber follow a logarithmic course with time. As a result, it is possible to define rate of flow as the ratio of flow at constant tension to the logarithm of the time, and rate of relaxation as the ratio of the decline in tension at constant elongation to the logarithm of the time. A study of tension-rate of flow diagrams at different temperatures has shown that, at room temperature, a considerable part of the total flow measured is reversible and therefore must be considered as pseudo-flow. This pseudo-flow is caused by a retardation in crystallization, and diminishes with increase in temperature. As a result, with increasing temperature, the total rate of flow passes through a minimum. An analogous situation occurs with the phenomenon of relaxation.

Effect on Vulcanized Rubber Compounds of Immersion in Boiling Water

1931 ◽  
Vol 4 (3) ◽  
pp. 426-436
Author(s):  
K. J. Soule
Keyword(s):  
Water Absorption ◽  
Room Temperature ◽  
Anomalous Behavior ◽  
Boiling Water ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Actual Change

Abstract Further work is very desirable on the effect of different accelerators, antioxidants, and fluxes. It is possible that their study will throw more light on the mechanism of the swelling phenomena, and also help to explain the anomalous behavior of some of the fillers tested. It would also seem to be worth while to study the action of a few selected stocks in water, at several temperatures between room temperature and 100° C., to determine if the water absorption and swelling merely increase with rising temperatures, or whether there might be an actual change in behavior at different temperatures.

Influence of Temperature upon the Texture Evolution and Mechanical Behaviour of Zircaloy-4

2011 ◽  
Vol 702-703 ◽  
pp. 834-837
Author(s):  
Peter Honniball ◽  
Michael Preuss ◽  
Joao Quinta da Fonseca
Keyword(s):  
Mechanical Behaviour ◽  
Room Temperature ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Crystal Plasticity Finite Element ◽  
Ebsd Data ◽  
Electron Backscatter ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Backscatter Diffraction

The mechanical behaviour and texture evolution during uniaxial compression of Zircaloy-4 at different temperatures (25, 300, 500 C) has been studied. At room temperature and 300 C the texture evolution and strain-hardening behaviour observed are attributed to the activation of {10-12} tensile twinning, which can be identified in optical micrographs and electron backscatter diffraction (EBSD) data. The influence of twinning upon the texture evolution and hardening rate becomes less apparent with increasing temperature. Nevertheless twinning is still active at 500 C. Simulation of the texture evolution at 500 C using crystal plasticity finite element modelling (CPFEM) indicates that slip alone cannot explain the experimentally observed textures at this temperature.

Effects of Homogenizing and Extrusion on Elongation of As-Cast AZ80 Magnesium Alloy

2012 ◽  
Vol 626 ◽  
pp. 386-390
Author(s):  
Yao Jin Wu ◽  
Bao Hong Zhang ◽  
Yong Biao Yang ◽  
Zhi Min Zhang
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Clear Correlation ◽  
Homogenization Treatment ◽  
Az80 Magnesium Alloy ◽  
Different Temperatures ◽  
Az80 Alloy ◽  
Increasing Temperature

This paper presents the results of an investigation of the effects of homogenizing heat treatment and extrusion on plasticity of the as-cast AZ80 magnesium alloy. Both the homogenized and non-homogenized billets of AZ80 alloy were forward extruded at several different temperatures and different extrusion ratios. The effects of homogenization and extrusion on plasticity were evaluated by conducting tensile tests on these billets at room temperature and comparing their elongations. The experimental results showed that the elongation of the as-cast AZ80 alloy was increased by 67% after the homogenization treatment. After extrusion, the elongation of both the homogenized and non-homogenized AZ80 alloy increased significantly. The elongation of the homogenized billets decreased gradually with increasing temperature. For the non-homogenized billets, however, the elongation decreased sharply with temperature from 300 to 350 °C and then increased gradually with increasing temperature. There was not clear correlation between the elongations of both the homogenized and non-homogenized billets and the extrusion ratio.

Analysis of C-V Characteristics of InP(p)/InSb/Al2O3/Au MIS Structures in Wide Temperature Range

2013 ◽  
Vol 685 ◽  
pp. 179-184
Author(s):  
M.A. Benamara ◽  
A. Talbi ◽  
Z. Benamara ◽  
B. Akkal ◽  
N. Chabane Sari ◽  
...  
Keyword(s):  
High Speed ◽  
Room Temperature ◽  
Electrical Characterization ◽  
State Density ◽  
Capacitance Voltage ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Accumulation Region ◽  
Interface Study

Superscript textThe III-V semiconductors materials and in particularly Indium Phosphide are a promising candidates for the elaboration of high speed electronic compounds. The importance of the interface study is increasing considerably in the last years to understand, the mechanism of interface formations and to control perfectly the technology of the elaborated compounds. This study presents an electrical characterization of InP(p)/InSb/Al2O3/ Au structures in the range of temperature varying from the temperature of liquid nitrogen to the temperature of 400°K. In order to give the evolution of electrical parameters of these structures with temperature, we have realized Capacitance-Voltage measurements at high frequency for different temperatures. The found results show that there is dispersion in the accumulation region as function with temperature. The quantity of positive charges in the insulator is estimated to 1.37×1012 atm/cm2 at room temperature. This value decreases slightly with increasing temperature. It varies fromSuperscript text 1.57×1012 atm/cm2 at 77°K to 1.12×1012 atm/cm2 at 400°K. The interface insulator/semiconductor of our samples presents a good electronical quality, the state density is equal to 4.1011 eV-1.cm-2 at room temperature, this one increases from 4.7×1010 eV-1.cm-2 to 7.1011 eV-1.cm-2 when temperature increases from 77°K to 400°K.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

scholarly journals A Comparative Electrochemical and Morphological Investigation on the Behavior of NiCr and CoCr Dental Alloys at Various Temperatures

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 256
Author(s):  
Florentina Golgovici ◽  
Mariana Prodana ◽  
Florentina Gina Ionascu ◽  
Ioana Demetrescu
Keyword(s):  
Low Temperatures ◽  
Artificial Saliva ◽  
Electrochemical Stability ◽  
Morphological Investigation ◽  
Dental Alloys ◽  
Ion Release ◽  
Icp Ms ◽  
Different Temperatures ◽  
Good Concordance ◽  
Increasing Temperature

The purpose of our study is to compare the behavior of two reprocessed dental alloys (NiCr and CoCr) at different temperatures considering the idea that food and drinks in the oral cavity create various compositions at different pH levels; the novelty is the investigation of temperature effect on corrosion parameters and ion release of dental alloys. Electrochemical stability was studied together with morphology, elemental composition and ions release determination. The results obtained are in good concordance: electrochemistry studies reveal that the corrosion rate is increasing by increasing the temperature. From SEM coupled with EDS, the oxide film formed on the surface of the alloys is stable at low temperatures and a trend to break after 310K. ICP-MS results evidence that in accordance with increasing temperature, the quantities of ions released from the alloys immersed in artificial saliva also increase, though they still remain small, less than 20 ppm.

scholarly journals Temperature-Dependent Stimulated Emission Cross-Section in Nd3+:YLF Crystal

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 431
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Michael Bass ◽  
Alessandra Toncelli
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Room Temperature ◽  
Radiative Decay ◽  
Emission Cross Section ◽  
Spectroscopic Properties ◽  
Stimulated Emission ◽  
Different Temperatures ◽  
Stimulated Emission Cross Section ◽  
Semi Empirical

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd3+ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the 4F3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the 4F3/2 to the 4I9/2, 4I11/2, and 4I13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull–Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the 4I11/2 and 4I13/2 levels.

Proteinase and phospholipase activities and development at different temperatures of yeasts isolated from bovine milk

2011 ◽  
Vol 78 (4) ◽  
pp. 385-390 ◽  
Author(s):  
Priscilla A Melville ◽  
Nilson R Benites ◽  
Monica Ruz-Peres ◽  
Eugenio Yokoya
Keyword(s):  
Dairy Products ◽  
Room Temperature ◽  
Bovine Milk ◽  
Raw Milk ◽  
Pathogenic Potential ◽  
Proteinase Production ◽  
Different Temperatures ◽  
Quality Of Milk ◽  
Means Of Transmission

The presence of yeasts in milk may cause physical and chemical changes limiting the durability and compromising the quality of the product. Moreover, milk and dairy products contaminated by yeasts may be a potential means of transmission of these microorganisms to man and animals causing several kinds of infections. This study aimed to determine whether different species of yeasts isolated from bovine raw milk had the ability to develop at 37°C and/or under refrigeration temperature. Proteinase and phospholipase activities resulting from these yeasts were also monitored at different temperatures. Five genera of yeasts (Aureobasidium sp., Candida spp., Geotrichum spp., Trichosporon spp. and Rhodotorula spp.) isolated from bovine raw milk samples were evaluated. All strains showed one or a combination of characteristics: growth at 37°C (99·09% of the strains), psychrotrophic behaviour (50·9%), proteinase production (16·81% of the strains at 37°C and 4·09% under refrigeration) and phospholipase production (36·36% of the isolates at 37°C and 10·9% under refrigeration), and all these factors may compromise the quality of the product. Proteinase production was similar for strains incubated at 37°C (16·81% of the isolates) and room temperature (17·27%) but there was less amount of phospholipase-producing strains at room temperature (15·45% of the isolates were positive) when compared with incubation at 37°C (36·36%). Enzymes production at 37°C by yeasts isolated from milk confirmed their pathogenic potential. The refrigeration temperature was found to be most efficient to inhibit enzymes production and consequently ensure better quality of milk. The viability of yeasts and the activity of their enzymes at different temperatures are worrying because this can compromise the quality of dairy products at all stages of production and/or storage, and represent a risk to the consumer.

scholarly journals E/D-Mode GaN Inverter on a 150-mm Si Wafer Based on p-GaN Gate E-Mode HEMT Technology

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 617
Author(s):  
Li-Fang Jia ◽  
Lian Zhang ◽  
Jin-Ping Xiao ◽  
Zhe Cheng ◽  
De-Feng Lin ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Room Temperature ◽  
Supply Voltage ◽  
High Input ◽  
Smart Power ◽  
Input Noise ◽  
Power Integrated Circuit ◽  
Different Temperatures ◽  
Device Technology ◽  
Si Wafer

AlGaN/GaN E/D-mode GaN inverters are successfully fabricated on a 150-mm Si wafer. P-GaN gate technology is applied to be compatible with the commercial E-mode GaN power device technology platform and a systematic study of E/D-mode GaN inverters has been conducted with detail. The key electrical characters have been analyzed from room temperature (RT) to 200 °C. Small variations of the inverters are observed at different temperatures. The logic swing voltage of 2.91 V and 2.89 V are observed at RT and 200 °C at a supply voltage of 3 V. Correspondingly, low/high input noise margins of 0.78 V/1.67 V and 0.68 V/1.72 V are observed at RT and 200 °C. The inverters also demonstrate small rising edge time of the output signal. The results show great potential for GaN smart power integrated circuit (IC) application.

scholarly journals Simulation of FDSOI-ISFET with Tunable Sensitivity by Temperature and Dual-Gate Structure

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1585
Author(s):  
Hanbin Wang ◽  
Jinshun Bi ◽  
Mengxin Liu ◽  
Tingting Han
Keyword(s):  
Gate Voltage ◽  
Computer Aided Design ◽  
Silicon On Insulator ◽  
Fully Depleted ◽  
Gate Structure ◽  
Different Temperatures ◽  
Dual Gate ◽  
Sensitivity Changes ◽  
Increasing Temperature ◽  
Aided Design

This work investigates the different sensitivities of an ion-sensitive field-effect transistor (ISFET) based on fully depleted silicon-on-insulator (FDSOI). Using computer-aided design (TCAD) tools, the sensitivity of a single-gate FDSOI based ISFET (FDSOI-ISFET) at different temperatures and the effects of the planar dual-gate structure on the sensitivity are determined. It is found that the sensitivity increases linearly with increasing temperature, reaching 890 mV/pH at 75 °C. By using a dual-gate structure and adjusting the control gate voltage, the sensitivity can be reduced from 750 mV/pH at 0 V control gate voltage to 540 mV/pH at 1 V control gate voltage. The above sensitivity changes are produced because the Nernst limit changes with temperature or the electric field generated by different control gate voltages causes changes in the carrier movement. It is proved that a single FDSOI-ISFET can have adjustable sensitivity by adjusting the operating temperature or the control gate voltage of the dual-gate device.

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