Rheological Properties of PFPE Lubricants at Elevated Temperatures

2016 ◽  
Vol 52 (7) ◽  
pp. 1-4 ◽  
Author(s):  
Pil Seung Chung ◽  
Wonyup Song ◽  
Lorenz T. Biegler ◽  
Myung S. Jhon
Keyword(s):  
Rheological Properties ◽  
Elevated Temperatures ◽  
Pfpe Lubricants

scholarly journals Influence of Guayule Resin as a Bio-Based Additive on Asphalt–Rubber Binder at Elevated Temperatures

Recycling ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 38 ◽  
Author(s):  
Ahmed Hemida ◽  
Magdy Abdelrahman
Keyword(s):  
Rheological Properties ◽  
Elevated Temperatures ◽  
Thermo Gravimetric Analysis ◽  
Crumb Rubber ◽  
Environmental Concerns ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Asphalt Cement ◽  
Asphalt Rubber ◽  
Liquid Phases

This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with the bio-based material “guayule resin.” This replacement could be beneficial in terms of sustainability, economics, and environmental concerns related to the asphalt industry. Nine asphalt–rubber–guayule binders were investigated to find their rheological properties. Consecutively, the study proceeded with five selected binders being compared to the original asphalt (PG64-22). Investigations underwent whole matrices (crumb rubber modifier (CRM) residue included) and liquid phases (CRM residue extracted). Additionally, these properties were partially sought for their corresponding asphalt–rubber binders to compare and judge the contribution of the guayule resin. Likewise, a thermo-gravimetric analysis was done for the guayule resin to recognize its moisture and composition complexity. Such an analysis was also done for the as-received CRM and some extracted CRMs to determine the release and residue of rubber components. Outcomes showed that the guayule resin has the potential to compensate the performance required against the original asphalt at elevated temperatures while greatly decreasing the asphalt cement proportion. For instance, a blend of 62.5% asphalt, 12.5% CRM, and 25% guayule resin provided better performance than that of the original asphalt.

The Effect of Refrigerated Storage on the Rheological Properties of Three Commercial Mozzarella Cheeses

2008 ◽  
Vol 4 (4) ◽  
Author(s):  
Edward B Muliawan ◽  
Savvas G Hatzikiriakos
Keyword(s):  
Rheological Properties ◽  
Viscoelastic Properties ◽  
Elevated Temperatures ◽  
Maxwell Model ◽  
Model Parameters ◽  
Refrigerated Storage ◽  
Mozzarella Cheese ◽  
Relaxation Dynamics ◽  
Generalized Maxwell Model ◽  
Linear Viscoelastic

The linear and non-linear viscoelastic properties and the effect of refrigerated storage on the rheological properties of three commercial mozzarella cheeses was studied. The linearity of the rheological behavior of mozzarella cheese increases with temperature because of the ability for the cheese to flow easier at higher temperatures as well as the lack of yield stress at elevated temperatures. The generalized Maxwell model parameters obtained from the linear viscoelastic data were found to describe the linear relaxation dynamics of the mozzarella cheese satisfactorily. It is also shown that the damping function of mozzarella cheese, which is a measure of the degree of non-linearity, can be described by a generalized Zapas model. Although, the different commercial mozzarella cheeses do not exhibit linear viscoelastic differences at room temperature, they do show significant differences at 60°C. The effect of refrigerated storage on the linear viscoelastic properties is brand-dependent and indicates structural differences among cheese samples. Finally it is shown that the dynamic moduli decrease with longer refrigerated storage due to proteolysis activities and/or weakening of the casein matrix.

Effects of Temperature and Chemical Admixtures on the Properties of Rock-Based Geopolymers Designed for Zonal Isolation and Well Abandonment

2021 ◽  
Author(s):  
Fawzi Chamssine ◽  
Mahmoud Khalifeh ◽  
Elsayed Eid ◽  
Mona Wetrhus Minde ◽  
Arild Saasen
Keyword(s):  
Mechanical Properties ◽  
Rheological Properties ◽  
Elevated Temperatures ◽  
Setting Time ◽  
Strength Development ◽  
Fluid Loss ◽  
Rotational Viscometer ◽  
Well Abandonment ◽  
Uniaxial Compressive Strength Test ◽  
The Impact

Abstract In this paper, the impact of temperature and admixture-based salts on the mechanical and rheological properties, and composition of geopolymers was studied. Neat geopolymer and Class-G cement, manufactured by Dyckerhoff, were used as reference samples at elevated temperatures. To enhance the additive properties of the geopolymer slurry, a combination of K and Zn was examined with a variety of K:Zn ratio ranging from ∼0.15 to ∼0.25. The workability of samples was tested by using an atmospheric consistometer, while other rheological properties were examined by running fluid loss test, and rotational viscometer test. The sample with the best workability was cured for 1, 3, and 7 days at bottomhole static temperatures of 70 and 80°C and pressure of 140 MPa where the mechanical properties were examined by ultrasonic cement analyzer and uniaxial compressive strength test. X-ray diffraction was used to analyze the composition of samples at different curing times and temperatures. The obtained results showed that the salt derivative admixtures have a significant impact on the oligomerization and polycondensation phases, where it distinctively elongated the setting time, enhanced strength, and strength development. On the other hand, the temperature effect was clearly observed by reducing rheological properties, while maintaining similar mechanical properties.

Improving Oil well Cement Slurry Performance Using Hydroxypropylmethylcellulose Polymer

2013 ◽  
Vol 787 ◽  
pp. 222-227 ◽  
Author(s):  
Ghulam Abbas ◽  
Sonny Irawan ◽  
Sandeep Kumar ◽  
Ahmed A.I. Elrayah
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Rheological Properties ◽  
Elevated Temperatures ◽  
Free Water ◽  
Oil Wells ◽  
Fluid Loss ◽  
Cement Slurry ◽  
Multifunctional Additive ◽  
Wide Range

At present, high temperature oil wells are known as the most problematic for cementing operation due to limitations of polymer. The polymers are significantly used as mutlifunctional additives for improving the properties of cement slurry. At high temperature, viscosity of polymer decreases and unable to obtained desired properties of cement slurry. It becomes then major cause of fluid loss and gas migration during cementing operations. Thus, it necessitates for polymers that can able to enhance viscosity of slurry at elevated temperatures. This paper is aiming to study Hydroxypropylmethylcellulose (HPMC) polymer at high temperature that is able to increase the viscosity at elevated temperature. In response, experiments were conducted to characterize rheological properties of HPMC at different temperatures (30 to 100 °C). Then it was incorporated as multifunctional additive in cement slurry for determining API properties (fluid loss, free water, thickening time and compressive strength). It was observed that HPMC polymer has remarkable rheological properties that can have higher viscosity with respect to high temperatures. The best concentration of HPMC was found from 0.30 to 0.50 gallon per sack. This concentration showed minimal fluid loss, zero free water, high compressive strength and wide range of thickening time in cement slurry. The results signified that HPMC polymer is becoming multifunctional additive in cement slurry to improve the API properties of cement slurry and unlock high temperature oil wells for cementing operations.

Modification of bitumen by EPDM blended with hybrid nanoparticles: Physical, thermal, and rheological properties

2018 ◽  
Vol 33 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Atefeh Ghoreishi ◽  
Mojtaba Koosha ◽  
Navid Nasirizadeh
Keyword(s):  
Rheological Properties ◽  
Softening Point ◽  
Elevated Temperatures ◽  
Viscoelastic Behavior ◽  
Hybrid Nanoparticles ◽  
Modified Bitumen ◽  
Thermal Degradation Behavior ◽  
Complex Shear ◽  
Linear Viscoelastic ◽  
Temperature Susceptibility

The aim of this research is to study the physical, thermal, and rheological properties of bitumen modified with ethylene propylene diene monomer (EPDM) elastomer and hybrid nanoparticles including carbon nanotubes (CNTs) masterbatch and bentonite nanoclay. Modified bitumen samples were prepared by mixing 60/70 bitumen with 3% EPDM, 0.1% CNT masterbatch, and 1.5% and 4.5% bentonite nanoclay. It was found that addition of these nanoparticles increased the softening point, reduced the penetration degree as well as temperature susceptibility of the modified bitumens. Results of rheological studies in the linear viscoelastic range showed that for the hybrid samples reinforced with EPDM, CNT masterbatch, and nanoclay, complex shear modulus was increased at high temperatures and the rutting factor was shifted from 81°C for the unmodified bitumen to >90°C for the EPDM-nano-modified bitumens. Thermogravimetric analysis also showed the improvement in the thermal degradation behavior of the hybrid samples. Our results indicate that the addition of small amounts of the additives used in this work can highly enhance the viscoelastic behavior of the bitumen at elevated temperatures. According to the findings of this work, the addition of EPDM (3%) and hybrid nanoparticles of CNT masterbatch (0.1%) and bentonite nanoclay (1.5%) to bitumen can synergistically result in the lowest penetration degree, highest softening point, and lowest temperature susceptibility and has the potential to have a better performance in warm areas.

scholarly journals Component Analysis of Bio-Asphalt Binder Using Crumb Rubber Modifier and Guayule Resin as an Innovative Asphalt Replacer

2020 ◽  
Author(s):  
Ahmed Hemida ◽  
Magdy Abdelrahman
Keyword(s):  
Rheological Properties ◽  
Elevated Temperatures ◽  
Chemical Interaction ◽  
Asphalt Binder ◽  
Thermo Gravimetric Analysis ◽  
Component Analysis ◽  
Crumb Rubber ◽  
Physical Interaction ◽  
Gravimetric Analysis ◽  
Asphalt Rubber

This research seeks to interpret the component analysis of an innovative bio-asphalt binder using guayule resin in addition to crumb rubber modifier (CRM) at high concentrations. Such asphalt modification aims to minimize the dependency on virgin asphalt binder and provide new solutions concerning sustainable, flexible pavement industry. Guayule resin is a promising bioresource for asphalt binder replacement. By now, it could be considered a no value byproduct extracted during the guayule natural rubber production. CRM is a recycled material derived from scrap tires. The provided interpretation could help in understanding the asphalt-rubber-guayule interaction mechanism. Fourier transform infrared spectroscopy (FTIR), supported by thermo-gravimetric analysis (TGA), was used to investigate the component analyses of guayule resin composition, asphalt guayule interaction, and asphalt rubber guayule interaction, compared to corresponding asphalt rubber interaction. Additionally, the rheological properties at elevated temperatures were provided to link the microscale properties with the final product performance. The study clarified the distinct carbon and hydrogen compositional elements of guayule resin. Asphalt and guayule resin have similarities in chemical composition and rheological behavior with temperature susceptibility. The asphalt guayule binder had physical interaction. However, when both interacted with rubber, a chemical interaction was attributed, with no difference in rubber dissolution tendency, in asphalt rubber guayule, compared to asphalt rubber. A bio-binder composed of 62.5% asphalt, 25% guayule and 12.5% CRM had the potential to provide rheological properties better than base asphalt. Such behavior was interpreted by a high release of rubber components.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Observations oh Nucleation and Growth of Voids in Nickel

1970 ◽  
Vol 28 ◽  
pp. 414-415
Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel
Keyword(s):  
High Purity ◽  
Growth Stage ◽  
Elevated Temperatures ◽  
Early Growth ◽  
Nucleation And Growth ◽  
Pure Nickel ◽  
Different Temperatures ◽  
Total Fluence ◽  
Neutron Exposure ◽  
Growth Of Voids

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.

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