scholarly journals Elastic-plastic transition stresses in a thin rotating disc with rigid inclusion by infinitesimal deformation under steady-state temperature

2010 ◽  
Vol 14 (1) ◽  
pp. 209-219 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
Outer Surface ◽  
Room Temperature ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Angular Speed ◽  
Incompressible Material ◽  
Plastic State ◽  
Rotating Disc ◽  
Elastic Plastic ◽  
Different Temperatures

Stresses for the elastic-plastic transition and fully plastic state have been derived for a thin rotating disc with rigid shaft at different temperatures and results have been discussed and depicted graphically. It has been observed that at room temperature rotating disc made of compressible material and of smaller radii ratio yields at the internal surface at a higher angular speed as compared to rotating disc made of incompressible material. With the introduction of thermal effect rotating disc yields at the outer surface at a lesser angular speed as compared to rotating disc at room temperature. The circumferential stress is maximum at the outer surface of the rotating disc with further increases with the increase in temperature. It means that angular speed of the rotating disc is less than that of the temperature-loaded disc in the fully plastic case.

scholarly journals Thermo elastic-plastic transition in a thin rotating disc with inclusion

2007 ◽  
Vol 11 (1) ◽  
pp. 103-118 ◽  
Author(s):  
Kumar Gupta ◽  
P Pankaj
Keyword(s):  
Thermal Effect ◽  
Internal Surface ◽  
Angular Speed ◽  
Incompressible Material ◽  
Plastic State ◽  
Percentage Increase ◽  
Compressible Material ◽  
Rotating Disc ◽  
Elastic Plastic ◽  
Different Temperatures

Stresses for the elastic-plastic transition and fully plastic state have been derived for a thin rotating disc with shaft at different temperatures and results have been discussed and depicted graphically. It has been observed that the rotating disc with inclusion and made of compressible material requires lesser angular speed to yield at the internal surface and higher percentage increase in angular speed to become fully plastic as compare to disc made of incompressible material. With the introduction of thermal effect the rotating disc with inclusion required lesser angular speed to yield at the internal surface. Rotating disc made of compressible material with inclusion requires higher percentage increase in angular speed to become fully-plastic as compare to disc made of incompressible material. Thermal effect also increases the values of radial and circumferential stresses at the internal surface for fully-plastic state. .

scholarly journals Systematic Review Based on the Study of Elastic-Plastic Transition Stresses

2021 ◽  
Vol 23 (07) ◽  
pp. 1077-1084
Author(s):  
Gurinder Kaur ◽  
◽  
Nishi Gupta ◽  
Keyword(s):  
Systematic Review ◽  
Thermal Effect ◽  
Radial Stress ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Angular Speed ◽  
Plastic State ◽  
Compressible Material ◽  
Rotating Disc ◽  
Elastic Plastic

A systematic review based upon the study of elastic-plastic transition stresses. A worthwhile work about the analysis of elastic-plastic transition stresses in different rotating materials by varying different parameters is discussed. In the case of compressible material, the strain rates have a maximum value at the internal surface. It has been observed that radial stress has a higher value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress with thermal effect and this value of radial stress further increases. With the increase of angular speed, the value of radial stress further increases as compared to the case with no thermal effect. The magnitude of the stresses and pressure reduce with the variation of thickness needed for a fully plastic state. At the inner surface, the effect of heat increases stress for compressible material. The thickness and density parameters decrease the value of angular speed at the internal surface of the rotating disc of compressible material as well as incompressible materials. The radial and the hoop stress, both decrease with the increased value of temperature at the Elastic-Plastic stage, but with the reverse result obtained for a fully Plastic state.

scholarly journals Creep transition stresses in a thin rotating disc with shaft by finite deformation under steady-state temperature

2010 ◽  
Vol 14 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
Thermal Effect ◽  
Radial Stress ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Angular Speed ◽  
Incompressible Material ◽  
Strain Rates ◽  
Rotating Disc ◽  
Maximum Value ◽  
Steady State Temperature

Creep stresses and strain rates have been derived for a thin rotating disc with shaft at different temperature. Results have been discussed and presented graphically. It has been observed that radial stress has maximum value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress and this value of radial stress further increase with the increase of angular speed. With the introduction of thermal effect, it has been observed that radial stress has higher maximum value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress, and this value of radial stress further increases with the increase of angular speed as compared to the case without thermal effect. Strain rates have maximum values at the internal surface for compressible material. Rotating disc is likely to fracture by cleavage close to the inclusion at the bore.

Elastic-Plastic State of Inhomogeneous Soil Array with a Spherical Cavity

2013 ◽  
Vol 842 ◽  
pp. 462-465 ◽  
Author(s):  
Vladimir I. Andreev ◽  
Anatoliy S. Avershyev ◽  
Stanislaw Jemiolo
Keyword(s):  
Plastic Deformation ◽  
Outer Surface ◽  
Spherical Cavity ◽  
Plastic Material ◽  
Plastic State ◽  
Cavity Model ◽  
Limit Loads ◽  
Elastic Plastic ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The article deals with the elastic-plastic state of inhomogeneous array with a spherical cavity. Model is used thick-walled ball of an elastic-perfectly plastic material (Prandtl diagram). It is shown that in the inhomogeneous material, depending on the inhomogeneity functions describing the change of the modulus of elasticity and yield stress of soil plastic deformation may appear on both the inner and outer surface of the ball and inside it. Are found values of the limit loads, displacement diagrams are constructed in an array.

scholarly journals Steady thermal stress and strain rates in a circular cylinder with non-homogeneous compressibility subjected to thermal load

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 81-92 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
External Surface ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Incompressible Material ◽  
Pressure Effects ◽  
Homogeneous Material ◽  
Strain Rates ◽  
Compressible Material ◽  
Homogeneous Case ◽  
Effects Of Temperature

The non-homogeneity is assumed due to variation of modulus of compression. It has seen that in the presence of temperature, a cylinder made of non-homogeneous material k<0 (Non-homogeneity is less at internal surface than at outer surface) require high pressure to become fully plastic as is required for initial yielding and this pressure goes on increasing with the increases in temperature, showing that a cylinder made of non-homogeneous material k<0 is on the safer side of design. For homogeneous case, it has been observed that the circumferential stress has maximum value at the external surface of the cylinder made of incompressible material as compared to compressible material. For Homogeneous case, with effects of temperature reduces the stresses at the external surface of the cylinder in comparison to pressure effects only. Strain rates are found to be maximum at the internal surface of the cylinder made of compressible material and they decrease with the radius. With the introduction of temperature effect, the creep rates have higher values at the internal surface but lesser values at the external surface as compare to a cylinder subjected to pressure only.

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).

Elasto-plastic state of curve beam system subjected to complex loading

1996 ◽  
Vol 18 (4) ◽  
pp. 14-22
Author(s):  
Vu Khac Bay
Keyword(s):  
Cylindrical Shell ◽  
Solution Method ◽  
Complex Loading ◽  
Numerical Results ◽  
Elastic Solution ◽  
Plastic State ◽  
Curve Beam ◽  
Elastic State ◽  
Elastic Plastic ◽  
Beam System

Investigation of the elastic state of curve beam system had been considered in [3]. In this paper the elastic-plastic state of curve beam system in the form of cylindrical shell is analyzed by the elastic solution method. Numerical results of the problem and conclusion are given.

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.

Sign in / Sign up

Export Citation Format

Share Document