Academic literature on the topic 'Temperature Retarder'
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Journal articles on the topic "Temperature Retarder"
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Petriashvili, Gia, Andro Chanishvili, Nino Ponjavidze, et al. "Crystal Smectic G Phase Retarder for the Real-Time Spatial-Temporal Modulation of Optical Information." Chemistry & Chemical Technology 17, no. 4 (2023): 758–65. http://dx.doi.org/10.23939/chcht17.04.758.
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We have manufactured and investigated a novel phase retarder based on a rare and less studied liquid crystal phase, such as the Crystal Smectic G-phase prepared by mixing two certified nematic mixtures. The phase retarder is transparent in the visible and near-infrared parts of the optical spectrum. The temperature stability over a wide temperature range, high birefringence, and high strength, allow the production of various types of phase retarders that can be used in optics, optical chemical analysis,and polarimetry.
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Liu, Cheng Ye, and Jian Ming Shen. "Design Technologies of Eddy Current Retarder Used in an Automobile." Applied Mechanics and Materials 251 (December 2012): 134–38. http://dx.doi.org/10.4028/www.scientific.net/amm.251.134.
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Auxiliary brake sets had been widely used for heavy duty trucks and advanced buses. They played a role of split-flow braking load of main brake system. As one of auxiliary brake sets eddy current retarder had good braking performance and braking stability, and it is automotive and maintain constant speed by its continual braking. In this paper, key technologies of eddy current retarder, such as braking torque, working volt and current, magnetic circuit, material of rotor plate and iron, heat dissipation performance of rotor plate, match between eddy current retarded and automobile, and effect of temperature rise on its braking performance were presented and discussed in detail. Meanwhile, advantage and disadvantage of eddy current retarder were analyzed.
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Wu, Chao, Zhen Chuan Song, Shou Sheng Tang, and Wei Gang Shan. "The Experimental Study of Unload on Temperature Characteristics of Hydraulic Retarder." Applied Mechanics and Materials 620 (August 2014): 255–61. http://dx.doi.org/10.4028/www.scientific.net/amm.620.255.
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The experimental study of unload on temperature characteristics is put up for heavy vehicle hydraulic retarder, forms the retarder unload testing method of temperature characteristics, confirms the relationship between the temperature of hydraulic retarder inner cavity and unload torquecavity air density, which can be used to instruct the simulation of retarder inside flow field in unload condition and actualize method to reduce air losing, and it lays the foundation for developing mechanism research to reduce air losing of retarder.
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Koo, Kyung Mo, Gyu Yong Kim, Hiroyuki Miyauchi, and Yeon Woo Kang. "Properties of Autogenous Shrinkage in High-Strength Mass Concrete According to Hydration Heat Velocity." Advanced Materials Research 311-313 (August 2011): 1993–99. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.1993.
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The early-age properties and relationships between hydration heat and autogenous shrinkage in high-strength mass concrete are investigated through analysis of the history curves of hydration heat and autogenous shrinkage. To reduce the hydration heat velocity, micro encapsulated retarder (MR) that could retard cement reaction was applied. In the result of research, the hydration temperature and hydration heat velocity of high-strength mass concrete can be decreased with the reduction of size specimen and use of the retarder. A close relationship could be found between the hydration temperature and autogenous shrinkage; the higher the hydration heat velocity, the higher the autogenous shrinkage velocity and the greater the ultimate autogenous shrinkage.
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Yuan, Zhe, Wen Xing Ma, Wei Cai, Li Dan Fan, and Jian Jun Song. "Temperature Field Analysis on the Hydrodynamic Retarder of Heavy Vehicle." Advanced Materials Research 503-504 (April 2012): 1025–28. http://dx.doi.org/10.4028/www.scientific.net/amr.503-504.1025.
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According to the working characteristics of the hydrodynamic retarder, the hydrodynamic retarder D300 is chosen in this research. Based on three-dimensional flow theory, the internal temperature fields of hydrodynamic retarder with different liquid-filled ratios of 100%, 75%, 50%, 25% are numerically simulated. The standard k-ε model is chosen as turbulent model for calculation. The SIMPLEC algorithm is chosen as velocity-pressure coupling algorithm and the second order upwind scheme is used as discrete method. The mixture multiphase model is used to calculate the unsteady gas-liquid two-phase flow in the condition of partial charging. Through simulating and analyzing, it provides an important theoretical basis for the heat exchange of the hydrodynamic retarder at different gears.
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Kovalev, I. S. "MATHEMATICAL AND COMPUTER SIMULATION OF THE COMMERTIAL VEHICLE’S HYDRAULIC RETARDER." Vestnik SibADI 15, no. 3 (2018): 400–411. http://dx.doi.org/10.26518/2071-7296-2018-3-400-411.
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Introduction.The article represents the mathematical model of commercial vehicle’s hydraulic retarder. The model is based on the mathematical model of the variable filling hydraulic dynamometer.Materials and methods.The retarder model was designed with the possibility of its integration with the mathematical model of the engine cooling system. For this purpose, the state function of fluid temperature in a working chamber of the retarder was added to the retarder model. Consequently, fluid compression in the working chamber was included into the model to avoid unlimited filling because of possible high pressure at the retarder inlet.Results.The simulation model of the retarder was established as LMS Amesim submodel using C-programming language. For testing, the retarder simulation model was integrated with the Amesim models of the engine cooling system and with the powertrain and vehicle movement dynamics. In addition, brake torque regulation wassynthesized on PI controllers.Discussion and conclusions. During simulation of the vehicle movement on the mountain route expectable results were obtain, such as continuous braking via the retarder, which led to increasing of the cooling system’s fluid temperature. Therefore, overfilling of the retarder working chamber didn’t occur through the fluid compression. The retarder model could be applied to determine retarder design influence at vehicle functioning. For instance, it could be used for development of the algorithms’ control.
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Lu, Ya, Ming Li, Zi Han Guo, and Xiao Yang Guo. "Synthesis and Characterization Performance of a Novel High Temperature Retarder Applied in Long Cementing Interval." Materials Science Forum 847 (March 2016): 479–84. http://dx.doi.org/10.4028/www.scientific.net/msf.847.479.
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In view of the common polymer retarder of AMPS has poor sedimentation stability for slurry in high temperature, and thickening curve for unusual problems, a new terpolymers retarder PSIH which can solve the problem for the large temperature difference was synthesized by free radical aqueous solution copolymerization using styrene sulfonate (SSS), Itaconic acid (IA) and unsaturated hydroxyl ester monomers X . The structure and thermal stability of the copolymer was characterized with gel permeation chromatography (GPC), infrared spectroscopy (IR), and thermal gravimetric analysis (TG). The application performance of the retarder was assessed. The results demonstrated as follows. 1) The preferred synthesis conditions of the retarder is: the mass ratio of SSS/IA/X=9: 3: 1, temperature=60°C, initiator concentration =2%, the reaction time=5h, pH value was controlled in the neutral bias acidity. 2) Synthetic copolymer is the target product with appropriate molecular weight and has good thermal stability with thermal decomposition temperature of the main chain up to 375°C. 3) Compared with ordinary retarder the PSIH has merits as follows: excellent thermal resistant ability and sedimentation stability in high temperature; the rapid development of compressive strength in low temperature, and a big temperature span (30 °C~150 °C). The thickening time of the slurry with 1.0% PSIH is 245 min at 150°C; the compressive strength of cement with the same dosage can get up to 4.7MPa at 30 °C. In short, PSIH has excellent ability to cope with large temperature difference, providing a strong technical support for complex deep well cementing.
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Huang, Yi Qi, Gan Wei Cai, Yu Jiang, and Zhao Yu Luo. "Method of Genetic Algorithm Optimization Design of Permanent Magnet Retarder." Applied Mechanics and Materials 215-216 (November 2012): 362–67. http://dx.doi.org/10.4028/www.scientific.net/amm.215-216.362.
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This paper introduced the method of multidisciplinary design optimization based on genetic algorithm. The basic structure and new auxiliary braking mechanism of permanent magnet retarder was analyzed. The influences of magnetic field parameters, structural design parameters, rotor parameters and permanent magnet temperature parameters on the behaviors performance of the permanent magnet retarder were discussed. The conceptual model of permanent magnet retarder was developed to maximize the brake torque of the permanent magnet retarder. The design variables included the radial width and the axis length of permanent magnet, the number of permanent magnet, the radius of rotor, the thickness of rotor, and the air gas. The constraint conditions included permitting temperature of rotor, saturation magnetic flux density of magnet material, and relation of structural geometry. The results of design optimization variables were obtained by applying genetic algorithm. The multidisciplinary design optimization in this paper is an effective method for the global design optimization of the permanent magnet retarder.
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Soegiharto, Achmad Fauzan Hery. "The Investigation of Additional Cooling Fan on the Brake System to Overcome the Overheating Issue: A Case Study of Oil Cooler Retarder Brake." Journal of Mechanical Engineering 22, no. 1 (2025): 207–22. https://doi.org/10.24191/jmeche.v22i1.4565.
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The retarder brake is a critical component for articulated trucks, particularly in coal mining, where heavy loads are transported on steep terrains. The primary braking system often proves inadequate under these conditions, making the retarder brake essential. However, overheating in the retarder brake system reduces braking efficiency and increases the risk of mechanical failure. This study investigates the causes of overheating and assesses the effectiveness of adding a fan cooler to the oil retarder brake system. The methodology employed is quantitative observation, where a fan cooler was installed in the cooling line before the oil entered the retarder cooler. Data were collected during vehicle operations on a steep slope, with retarder oil temperatures measured before and after fan installation. The results show a temperature reduction from 120 °C to 108 °C after installing the fan cooler, significantly improving the cooling efficiency. Furthermore, the fan cooler installation reduced the vehicle’s breakdown unscheduled (BUS) time from 40 hours to just 2 hours. These findings suggest that adding a fan cooler prevents overheating and enhances the reliability and safety of braking systems in heavy-duty mining vehicles. Future studies could focus on integrating more excellent fan systems with enhanced pump capacity to optimize thermal management further.
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Ikpeka, Princewill Maduabuchi. "Effects of Additive Concentrations on Cement Rheology at Different Temperature Conditions." International Journal of Engineering Works (ISSN: 2409-2770) 06, no. 03 (2019): 50–70. https://doi.org/10.5281/zenodo.2583066.
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Cement slurries are designed to achieve zonal isolation; improve rheological properties and displacement efficiency of cementing system. Oil well cement slurries depend on temperature, additive concentrations; quality and quantity, to contribute to the placement and success of cementing operation. This study aims at analysing the effects of cement slurry additive concentration on rheology at different temperature conditions. Three additive concentrations were varied; Retarder, Fluid Loss Additive and Dispersant. Using full factorial design, 27 experiments were carried out to analyse the effect of these additives at different temperatures. Rheological properties like plastic viscosity, yield stress, shear rate and shear stress were experimentally determined at different temperatures and concentrations of additives. A simple cement slurry design which consists of: Dyckerhoff Class G, Fluid Loss Additive, Retarder, Dispersant, Defoamer and Drill Water, was used for the laboratory experiments. The slurry was conditioned in accordance with the procedure set out in API RP 10B-2. Linear regression was then used to build models describing the effect of temperature and additive concentration on plastic viscosity and yield point of the cement slurry. Ms-Excel plots were used as a tool in presenting the relationships between Shear Stress and shear rates at varying temperature conditions. Results from the analysis reveal that for a Temperature increase of 125% and Retarder concentration increase of 200%, there were significant decline in Plastic viscosity (-41%) and Yield point (-44%). Whereas increasing the Fluid loss additive by 100% caused a significant increase in Yield point (+51%) and relatively insignificant increase in Plastic Viscosity (+4.4%).<strong> </strong>
Dissertations / Theses on the topic "Temperature Retarder"
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GERARD, BRUNO. "Luminescence retardee stimulee electriquement dans les sulfures de zinc et de cadmium actives au cuivre, a l'or ou a l'argent et coactives a l'aluminium : application a un imageur mammographique numerique a memoire." Paris 6, 1988. http://www.theses.fr/1988PA066252.
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Etude de la faisabilite de cet imageur utilisant, comme principe d'acquisition de l'image x, l'effet gudden-pohl, phenomene de luminescence retarde stimulee electriquement (lse). Seuls zns et cds dopes par cu, au ou ag donne l'effet lse adequat apres une phase de sensibilisation. Variation de la luminescence en fonction de la dose de rayons x, du champ electrique, de la temperature, du dopage, etc. Modelisation de l'effet lse: l'enregistrement de l'image se fait par piegeage de trous sur des accepteurs dans la couche d'appauvrissement superficielle, la recombinaison radiative se produisant avec ces trous lorsque le champ electrique applique abaisse la barriere de potentiel superficielle. Elaboration d'une maquette en vue du developpement d'un imageur mammographique numerique
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Adohi, Bibi J. P. "Claquage électrique de films d'oxyde de polyphénylène réalisés par voie électrochimique." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0066.
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L'etude du claquage dans la geometrie d'electrode plan-sphere en variant le milieu montre que le claquage est provoque par des decharges electriques; l'analyse quantitative de ces decharges montre qu'un materiau peut etre caracterise par le champ cree au moment de la rupture par les charges deposees en surface. Etude de la conductivite electrique et du retard au claquage dans la geometrie plan-plan pour des echantillons autocicatricables en fonction de la temperature. Discussion du mecanisme de claquage
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Ding, Mengli. "Synthesis and drug delivery applications of iron(III) trimesate nanoMOFs." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASF095.
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Les matériaux hybrides organiques-inorganiques à l'échelle nanométrique (nanoMOFs) ont montré un potentiel significatif dans le domaine de la libération contrôlée de médicaments (DDS) en raison de leurs propriétés avantageuses, notamment des compositions modulables, une porosité importante, de grandes surfaces spécifiques, de bonnes biocompatibilités et dégradabilités. Parmi la famille de nanoMOFs, le MIL-100(Fe) (MIL signifie Matériaux de l'Institut Lavoisier), construit à partir de trimères de fer et de ligands organiques (trimésate), a été largement étudié, avec des données bien documentées sur la toxicité in vivo et la biocompatibilité, ce qui en fait un candidat très attractif pour des applications biomédicales. Nous avons rédigé deux articles de synthèse qui détaillent la synthèse et les applications des nanoMOFs dans le domaine biomédical. Ce travail nous a permis de cerner plusieurs défis qui subsistent encore dans l'application biomédicale et la production à grande échelle des nanoMOFs MIL-100(Fe). Tout d'abord, il est essentiel d'améliorer la stabilité des nanoMOFs pendant leur conservation et dans de milieux biologiques, en vue d'une utilisation industrielle ultérieure. De plus, les méthodes de synthèse des nanoMOFs MIL-100(Fe) nécessitent une optimisation pour répondre aux exigences de la production à grande échelle non consommatrice d'énergie et “verte” (sans solvants organiques toxiques). Pour tenter de pallier à ces problèmes, nous proposons la modification de la surface des nanoMOFs MIL-100(Fe) avec des copolymères ou oligomères biocompatibles afin d'améliorer leur stabilité et leur biocompatibilité in vitro/in vivo. En outre, nous avons optimisé la stratégie de synthèse des nanoMOFs à base de trimésate de fer pour permettre une production simple, écologique, continue, respectueuse de l'environnement et à faible consommation d'énergie. Tout d'abord, nous avons conçu et synthétisé une famille de copolymères de type peigne qui comportent des chaines de poly(éthylène glycol) (PEG), des fonctions alendronate pour permettre un bon anchrage aux MOFs, et des molécules fluorescentes afin de permettre une bonne détection des nanoparticules composites. L'association de ces matériaux est extrêmement rapide (10 secondes) et les rendements avoisinent les 100%. Tous les composants des copolymères peigne jouent un role dans ce processus efficace de recouvrement. Les MIL-100(Fe) revêtus de copolymères ont non seulement démontré une excellente stabilité, mais aussi un caractère “furtif” évitant la reconnaissance par les macrophages. Les nanoMOFs ont été obtenus par une synthèse micro-onde usuelle, mais nécessitant un grand apport d'énergie et des températures élevées (130 °C). Dans un effort d'optimiser la synthèse, nous avons exploré des méthodes nouvelles opérant à température ambiante. Tout d'abord nous avons utilisé des modulateurs afin de contrôler la taille des nanoMOFs à température ambiante. En faisant varier les rapports molaires (R) de l'acide acétique (modulateur) et de l'acide trimésique (ligand organique), nous avons obtenu des nanoMOFs avec des diamètres hydrodynamiques allant de 40 à 200 nm. Nous avons ensuite recouvert ces nanoparticules avec des oligomères à base de cyclodextrine, afin d'obtenir une bonne stabilité sans compromettre leur capacité d'encapsulation de molécules actives. Ces études proposent des méthodes vertes et ouvrent la voie à la production à grande échelle des nanoMOFs à base de trimésate de fer<br>Nanoscale metal-organic frameworks (nanoMOFs) have shown significant promise as drug delivery systems (DDS) due to their advantageous properties, including tunable compositions, uniform porosity, large surface areas, biocompatibility, and degradability. Among these, MIL-100(Fe) (MIL stands for Materials of the Lavoisier Institute) nanoMOFs, constructed from trimesate organic linkers and iron trimers, have been extensively studied. We reviewed here in detail their well-documented in vivo toxicity and biocompatibility data, making them highly attractive candidates for drug delivery applications. We highlighted several challenges which remain in the biomedical application and large-scale production of MIL-100(Fe) nanoMOFs. First, improving the storage stability of MIL-100(Fe) is essential for further use. Additionally, the synthesis methods for MIL-100(Fe) nanoMOFs need optimization to meet the demands of green (organic solvent free) large-scale production. To address these issues, we propose the surface modification of MIL-100(Fe) nanoMOFs with biocompatible copolymers or oligomers to enhance their stability and biocompatibility. Furthermore, we have investigated novel synthesis strategies for MIL-100(Fe) nanoMOFs to enable simple, green, environmentally friendly, and low-energy production. We designed and synthesized a family of comb-like copolymers, comprising grafted: i) “x” (0-6) alendronate (Ale) anchoring units; ii) “y” (up to 45) poly(ethylene glycol) (PEG) side chains with molecular weight of zK (z=0.5, 2, 5), and iii) fluorescent Alexa Fluor (F) moieties. The resulting FAlexPEGzKy copolymers spontaneoulsy adsorbed onto the nanoMOF's surface in aqueous media, reaching ~100% efficiency. We highlighted the cooperative effects of each component of the FAlexPEGzKy copolymers in the association process. The coating occurred in the top layers without affecting the nanoMOF's crystallinity. The composition of the FAlexPEGzKy copolymers was optimized to ensure a good stability in biological media, despite the non covalent nature of the coating. In addition, the copolymer-coated MIL-100(Fe) nanoMOFs not only exhibited excellent storage stability but also demonstrated a “stealth effect” in macrophage J774 cells, as shown by confocal studies and iron quantification in the cells. In these studies, MIL-100(Fe) nanoMOFs were prepared by a conventional microwave hydrothermal procedure at high temperature (130 °C). To optimize the process, we investigated the possibilities to obtain MIL-100(Fe) nanoMOFs at room temperature. We used modulators in an attempt to control the size of the nanoMOFs. By varying the molar ratio (R) of acetic acid (modulator) to trimesic acid (organic linker), we obtained MIL-100(Fe) nanoMOFs with hydrodynamic diameters ranging from 40 to 200 nm. However, the resulting MIL-100(Fe) nanoMOFs needed also to be coated to avoid their aggregation. The coatings based on crosslinked cyclodextrins did not compromise the drug-loading capacity of the nanoMOFs. In a nutshell, this work presents novel strategies to construct nanoMOFs in a lego-type manner, using materials prepared mostly using “green” chemistry
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Chowdhury, Usman. "Cutting rules for Feynman diagrams at finite temperature." 2010. http://hdl.handle.net/1993/3856.
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The imaginary part of the retarded self energy is of particular interest as it contains a lot of physical information about particle interactions. In higher order loop diagrams the calculation become extremely tedious and if we have to do the same at finite temperature, it includes an extra dimension to the difficulty. In such a condition we require to switch between bases and select the best basis for a particular diagram. We have shown in our calculation that in higher order loop diagrams, at #12;finite temperature, the R/A basis is most convenient on summing over the internal vertices and very efficient on calculating some particular diagrams while the result is most easily interpretable in the Keldysh basis for most other complex diagrams.
Books on the topic "Temperature Retarder"
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Horing, Norman J. Morgenstern. Quantum Mechanical Ensemble Averages and Statistical Thermodynamics. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198791942.003.0006.
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Chapter 6 introduces quantum-mechanical ensemble theory by proving the asymptotic equivalence of the quantum-mechanical, microcanonical ensemble average with the quantum grand canonical ensemble average for many-particle systems, based on the method of Darwin and Fowler. The procedures involved identify the grand partition function, entropy and other statistical thermodynamic variables, including the grand potential, Helmholtz free energy, thermodynamic potential, Gibbs free energy, Enthalpy and their relations in accordance with the fundamental laws of thermodynamics. Accompanying saddle-point integrations define temperature (inverse thermal energy) and chemical potential (Fermi energy). The concomitant emergence of quantum statistical mechanics and Bose–Einstein and Fermi–Dirac distribution functions are discussed in detail (including Bose condensation). The magnetic moment is derived from the Helmholtz free energy and is expressed in terms of a one-particle retarded Green’s function with an imaginary time argument related to inverse thermal energy. This is employed in a discussion of diamagnetism and the de Haas-van Alphen effect.
Book chapters on the topic "Temperature Retarder"
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Hanelt, Eckhard, Thomas Kammel, and Masato Kuwabara. "A New Retarder Film Improving the Temperature Dependent Performance of STN Displays." In Functional Materials. Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/3527607420.ch18.
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Zhang, Ying, Yunjin Wang, Guchang Zhang, et al. "An Efficient Retarded Acid System for Deep and High Temperature Carbonate Reservoirs." In Computational and Experimental Simulations in Engineering. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-42515-8_79.
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Nicklas, Jan, Lisa Ditscherlein, Shyamal Roy, Stefan Sandfeld, and Urs A. Peuker. "Microprocesses of Agglomeration, Hetero-coagulation and Particle Deposition of Poorly Wetted Surfaces in the Context of Metal Melt Filtration and Their Scale Up." In Multifunctional Ceramic Filter Systems for Metal Melt Filtration. Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_15.
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AbstractIn this chapter the fundamental principles of the interaction of poorly wetted particles with interfaces of particles and bubbles are investigated in a water-based model system in which the similarity of poor wettability of non-metallic inclusions by molten metal and the poor wettability of silanized metal-oxide-particles by water is utilized. Capillary forces, the presence of nanobubbles and absorption of gas layers accompany the decreased wettability and lead to strong attractive forces. The combined effect of wettability and surface roughness is analyzed in detail, employing a variety of Atomic Force Microscopy techniques, as well as theoretical modeling of capillary forces and retarded van der Waals Forces for layered substrates. These concepts are extended to investigate particle-bubble interactions at different approach velocities by Colloidal Probe Atomic Force Microscopy and analysis by the Stokes-Reynolds-Young–Laplace model. The influence of temperature effects on the particle–particle interaction is investigated by High Temperature Atomic Force Microscopy. Additionally, the suitability of different interaction potentials for the Molecular Dynamics simulation of sintering alumina nanoparticles is accessed. Macroscopic agglomeration and hetero-coagulation experiments in a baffled stirred tank provide an insight into the dynamics of agglomeration and hetero-coagulation at for the metal melt filtration typical inclusion concentrations and wettability states.
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Wang, Ru. "The Role of Polymer in Calcium Sulfoaluminate Cement-Based Materials." In Springer Proceedings in Materials. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-72955-3_16.
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AbstractIn order to realize sustainable development, new types of cements were paid more attention. Calcium sulfoaluminate (CSA) cement is a kind of eco-friendly cement that has the characteristics of low carbon emission, low energy consumption, fast setting and hardening, and so on. But the main hydration product ettringite (AFt) is quite sensitive to curing conditions that makes CSA cement-based materials sensitive to temperature and ageing. Polymer plays a key role in improving the properties of CSA cement mortar. Our researches showed that styrene-butadiene copolymer (SB) could result in a big reduction of zeta potential and conductivity of the CSA cement paste, retard the very initial hydration of CSA cement but not after 3 h, and lead to the generation of more AFt and aluminium hydroxide (AH3). With SB addition increasing, the yield stress, viscosity, thixotropy, fluidity and thus workability of CSA cement mortar were significantly improved. The mechanical strength of CSA cement mortar showed a reduction after a certain age, but when SB was added there was no reduction anymore under various curing conditions. SEM observation of the morphology accounts well for the changes in mechanical properties. The shrinkage, water capillary adsorption, and durability such as resistance to freezing and thawing cycle, carbonization and sulfate attack were also investigated. This paper reviewed the role of polymer in CSA cement-based materials taking SB as an example based on recent research work of our group.
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Touati, Khaled, and Fernando Tadeo. "Effects of the Temperatures on PRO." In Pressure Retarded Osmosis. Elsevier, 2017. http://dx.doi.org/10.1016/b978-0-12-812103-0.00003-9.
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MATSUMOTO, H. "RETARDED FORMULATION AT FINITE TEMPERATURE." In Thermal Field Theories. Elsevier, 1991. http://dx.doi.org/10.1016/b978-0-444-88903-4.50011-1.
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Adler, Stephen L. "Further Multiparticle Topicst." In Ouaternionic Quantum Mechanics and Ouanturn Fields. Oxford University PressNew York, NY, 1995. http://dx.doi.org/10.1093/oso/9780195066432.003.0010.
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Abstract In the third section, we examine the implementation of statistical mechanical methods in quaternionic quantum mechanics. We define thermal averages and construct thermally averaged retarded and “temperature” Green’s functions, which obey the usual temporal boundary conditions, but which are no longer related to one another by analytic continuation in Fourier space.
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Campos, Danilo Ferreira. "MÉTODOS DE REFRIGERAÇÃO DE CARCAÇAS E SUA RELAÇÃO COM A MACIEZ DA CARNE." In Avanços, Inovações e Saberes em Ciência e Tecnologia de Alimentos. Editora Científica Digital, 2024. http://dx.doi.org/10.37885/240817589.
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A aplicação de baixas temperaturas visa retardar as atividades microbianas, assim como as reações químicas e enzimáticas que provocam alterações nos alimentos. O processo de refrigeração é crucial para determinar a maciez da carne, e a escolha do método de refrigeração pode variar conforme a espécie, a velocidade de produção do produto e o tempo de prateleira desejado. Na refrigeração de carnes, são empregados procedimentos convencionais, método rápido, resfriamento ultrarrápido, super-rápido e por aspersão. Após o abate, a temperatura interna das carcaças geralmente varia entre 30 °C e 39 °C. Este calor residual deve ser dissipado durante o processo inicial de resfriamento, a fim de reduzir a temperatura interna da carcaça a valores próximos de 0 °C. Para o resfriamento das carcaças, as câmaras frigoríficas devem ser mantidas entre -4 °C e 0 °C, enquanto a temperatura ambiente não deve exceder 3 °C. Além disso, pode ser empregado outros métodos com o objetivo de alcançar a maciez da carne desejada em menos tempo, acelerar a transformação muscular em carne, diminuir os custos de produção nos frigoríficos, reduzir as perdas por evaporação durante o resfriamento e mitigar os efeitos adversos, como o encurtamento das fibras quando utilizado procedimentos de refrigeração mais intensivos.
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Wani, Khursheed Ahmad, Jamila Irfan, and Junaid Ahmad Malik. "Impact of Heat Stress on Embryonic Implantation." In Climate Change and Its Impact on Fertility. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4480-8.ch005.
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One of the expected effects of mammalian developmental defects is a rise in air temperature. Heat stress adversely affects embryo oogenesis, oocyte maturation, fertilization, and implantation. The number of defects caused by heat stress in all mammals is almost identical, but each species has its own particular sensitivity to specific defects. It suggests that genotype may have a significant effect on the type of defect, its occurrence, and its extent. By heat output and loss, the body temperature is usually preserved in a restricted range, but the equilibrium can be disrupted by illness, inadequate nutrition, and severe environmental temperature. Elevated maternal temperature during pregnancy, either by fever or any other means of heating, may result in embryo death, retarded development, abortion, and many embryonic defects such as cell proliferation, migration, differentiation and apoptosis or programmed cell death, structural and functional defects, and changes in maternal physiology. Maternal heat stress also reduces the levels of placental hormones. This chapter deals with the heat stress effect on reduction of reproductive function, implantation defects, etc. of different animals and humans.
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Wani, Khursheed Ahmad, Jamila Irfan, and Junaid Ahmad Malik. "Impact of Heat Stress on Embryonic Implantation." In Climate Change and Its Impact on Fertility. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4480-8.ch005.
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One of the expected effects of mammalian developmental defects is a rise in air temperature. Heat stress adversely affects embryo oogenesis, oocyte maturation, fertilization, and implantation. The number of defects caused by heat stress in all mammals is almost identical, but each species has its own particular sensitivity to specific defects. It suggests that genotype may have a significant effect on the type of defect, its occurrence, and its extent. By heat output and loss, the body temperature is usually preserved in a restricted range, but the equilibrium can be disrupted by illness, inadequate nutrition, and severe environmental temperature. Elevated maternal temperature during pregnancy, either by fever or any other means of heating, may result in embryo death, retarded development, abortion, and many embryonic defects such as cell proliferation, migration, differentiation and apoptosis or programmed cell death, structural and functional defects, and changes in maternal physiology. Maternal heat stress also reduces the levels of placental hormones. This chapter deals with the heat stress effect on reduction of reproductive function, implantation defects, etc. of different animals and humans.
Conference papers on the topic "Temperature Retarder"
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Kӧhler, M., and U. Heubner. "Time-Temperature-Sensitization and Time-Temperature-Precipitation Behavior of Alloy 625." In CORROSION 1996. NACE International, 1996. https://doi.org/10.5006/c1996-96427.
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Abstract Time-Temperature-Sensitization diagrams have been established for a low-carbon version of alloy 625 (UNS N06625). Sensitization in terms of a 50 μm (2 mils) intergranular penetration criterion starts after about 3 h aging time at 750°C (soft annealed condition) or after less than 1 h aging time at 800°C (solution annealed condition) when tested according to ASTM-G 28 method A. Grain boundary precipitation of carbides occurs during aging of both the soft annealed and the solution annealed material, but the soft annealed material exhibits a more pronounced general precipitation of Ni3(Nb,Mo) phase giving rise to more distinct loss of ductility. Sensitization of alloy 625 may be retarded by lowering its iron content.
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Kim, Chuljung. "A Comparative Study on Coating Performance of Inorganic Zinc Primer System and Inorganic Copolymer System by Long-Term Durability Test Including High Temperature Exposure at 540°C." In CONFERENCE 2023. AMPP, 2023. https://doi.org/10.5006/c2023-18820.
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Abstract Bulk items such as cast and forged valves are commonly to be installed randomly without information on operating conditions. Therefore, inorganic copolymer coating products covering a wide temperature range are applied with a thickness of 250 μm (10 mils) to 300 μm (12 mils). The inorganic zinc coating system is also able to be applied in a wide temperature range, but it is limited to up to 400°C (752°F) due to the zinc melting point of 420°C (788°F). However, if zinc coating is not applied as a topcoat, it may be retarded from being oxidized even at high temperatures. Thus, considering the application of a mixed coating system of inorganic zinc and inorganic copolymer, the complex cycling test of the heating furnace at 540°C (1004°F), QUV exposure, and salt spray was carried out for 3 months to compare with the inorganic copolymer system for coating performance. As a test result, it is confirmed that applying a mixed coating system composed of inorganic zinc and inorganic copolymer to a bulk valve is a suitable and optimal system under various temperature conditions for improving anti-corrosion performance and adhesion performance.
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Xyla, Aglaia, Pavlos Klepetsanis, and Petros G. Koutsoukos. "Calcium Carbonate-Calcium Sulfate Scale Formation at Elevated Temperatures." In CORROSION 1989. NACE International, 1989. https://doi.org/10.5006/c1989-89177.
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Abstract Scale formation is a commonly occuring problem in processes employing primary waters in which ions of sparingly soluble salts are in relatively high concentrations, depending on their origin. The problem is intensified at elevated temperatures and may be associated with corrosion phenomena when scale is deposited on metallic parts of equipment. Since a number of sparingly soluble salts may precipitate, the relationship between such salts is interesting. In this work the relationship between calcium carbonate and calcium sulfate dihydrate was investigated. Calcium carbonate solutions, saturated with respect to calcium sulfate dihydrate at 120°C and at 140°C,were seeded with synthetic calcium sulfate dihydrate seed crystals and the precipitation process was monitored by following calcium concentration in solution. The deposition of calcium carbonate was induced by the introduced gypsum crystals following the lapse of induction periods proportional to the solution supersaturation. The phase initially forming was found to be vaterite, converting subsequently into aragonite and calcite. The apparent rate order was found to be 5, a value very close to that found in spontaneous precipitation studies of the calcium carbonate system. It appeared that the phase forming is stabilized by temperature mainly, since the same phases were found in the absence of calcium sulfate dihydrate and at conditions of spontaneous precipitation at 140°C. At this temperature, it was found that the precipitation of calcium carbonate was retarded by the presence of the gypsum seed crystals.
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Was, Gary S., and Jin K. Sung. "Intergranular Cracking of Ni-16Cr-9Fe Alloys in High Temperature High Purity Water." In CORROSION 1990. NACE International, 1990. https://doi.org/10.5006/c1990-90519.
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Abstract The objective of this work is to provide a better understanding of the role of grain boundary chemistry in pure water intergranular stress corrosion cracking (SCC) of controlled purity Inconel 600-type alloys. High purity heats of Ni-16Cr-9Fe alloys with controlled addition of carbon, boron, and phosphorus were heat treated to produce chromium depletion, boron segregation, carbon segregation and phosphorus segregation, as well as inter-and intra-granular precipitation of chromium carbides. Constant extension rate (CER) tests were conducted at 360°C in deaerated high purity water (&lt;10 ppb O2) containing a hydrogen overpressure at an initial strain rate of 3x10−7 sec−1. The experimental results showed that 1) the Ni-Cr-Fe alloy containing no impurity addition exhibited significant IG cracking, 2) carbon in solution enhanced IG cracking resistance, 3) boron, and phosphorus segregation retarded IG cracking, 4) chromium depletion did not affect IG cracking, 5) cold work in the form of compression significantly increased IG cracking susceptibility, and 6) intergranular fracture was found in an ultra high purity alloy at 360°C and 400°C in flowing Ar tests. The results suggest that grain boundary impurities enhance resistance to IG cracking. In addition, it is likely that creep plays a role in IG cracking in 360°C water.
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Congleton, J., and R. N. Parkins. "Stress Corrosion Cracking of Steel in High Temperature Water." In CORROSION 1987. NACE International, 1987. https://doi.org/10.5006/c1987-87105.
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Abstract In an attempt to elucidate the mechanism of cracking for RPV steels in high temperature water, slow strain rate tests and polarization measurements have been made in a series of Fe-C-Mn-X alloys, where X was either Cr, Ni, Mo or Si (typical alloying elements for RPV steels) and on some relevant commercial alloys. The slow strain rate tests were performed in 250°C water at a series of applied potentials. On the criteria of the minimum potential at which cracking will occur, nickel and chromium retard cracking whereas molybdenum enhances cracking. The mechanism of cracking is discussed in terms of the maximum crack velocities observed and typical anodic current densities observed in polarization studies. Whereas it would be helpful to obtain straining electrode data in typical low conductivity reactor grade water to assist interpretation of the present results, the existing data suggests that the rate controlling mechanism for cracking is anodic dissolution at the crack tip, but that the observed crack growth rate might only be explained by the involvement of a significant contribution from mechanical tearing in the fracture process.
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Bota, Gheorghe M., Dingrong Qu, Srdjan Nesic, and H. Alan Wolf. "Naphthenic Acid Corrosion of Mild Steel in the Presence of Sulfide Scales Formed in Crude Oil Fractions at High Temperature." In CORROSION 2010. NACE International, 2010. https://doi.org/10.5006/c2010-10353.
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Abstract Increasing demand on the oil market has raised interest in oils with high naphthenic acid (NAP) concentration. These oils were previously considered of lower quality due to their corrosive character. Processing such oils at elevated temperatures encountered in refineries (300-350°C) may cause aggressive corrosive attack on the inside walls of equipment such as pipes and distillation towers. Naphthenic acid corrosion attack is a non-aqueous corrosion process and can be retarded by sulfur containing compounds inherently present in crude oil fractions in the form of soluble sulfides. Although these sulfides can be corrosive as well, they can also form iron sulfide scale on the metal surfaces potentially offering a degree of protection against naphthenic acid attack. However the iron sulfide scales can be removed from metal surfaces under the combined effects of high velocity flow and NAP attack. This research project has focused on the role of iron sulfide scales formed in different crude oil fractions on samples made from mild as well as chromium containing steels. They were exposed to naphthenic acid attack under high flow rates at high temperature.
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Maurer, J. R., and J. R. Kearns. "Enhancing the Properties of a 6% Molybdenum Austenitic Alloy with Nitrogen." In CORROSION 1985. NACE International, 1985. https://doi.org/10.5006/c1985-85172.
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Abstract The frequency of pitting and crevice corrosion failures in bleaching plants can be reduced with the use of austenitic stainless alloys containing increased levels of molybdenum and nitrogen. The corrosion and mechanical properties of a 6% molybdenum alloy, known as AL 6X™, have been improved with the addition of 0.2 wt% nitrogen. This has been shown by field and laboratory tests that have compared the nitrogen-bearing AL 6XN™ alloy to other stainless steels. The nitrogen addition in the AL 6XN alloy retarded secondary phase formation and lowered the solution annealing temperature. These improvements have made possible the production of thick plate that is suitable for multi-pass welding.
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Kawamura, H., H. Hirano, M. Koike, and M. Suda. "Inhibitory Effect of Boric Acid on Intergranular Attack and Stress Corrosion Cracking of Alloy 600 in High Temperature Water." In CORROSION 1995. NACE International, 1995. https://doi.org/10.5006/c1995-95408.
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Abstract The inhibitory effect of boric acid on the Intergranular Attack and Stress Corrosion Cracking (IGA/SCC) propagation behavior of steam generator (SG) tubing was studied under accelerated test conditions. Based on the analysis results of stress intensity factors at IGA/SCC crack tips, the notched C-ring tests were carried out to evaluate the effect of stress intensity and boric acid on the IGA/SCC crack propagation. The A.C. impedance measurement and Auger electron spectroscopy (AES) were also conducted to clarify the inhibitory effect of boric acid. Notched C-ring test results indicated that IGA/SCC crack velocity of alloy 600 increased gradually with increasing stress intensity factor in the range 4 to about 26 MPa·m1/2, which might be loaded on the IGA/SCC crack tips of actual SG tubes under PWR secondary conditions. Adding boric acid slightly retarded the crack velocity in both all volatile treatment (AVT) water and caustic solutions. IGA/SCC crack velocities were lower in nearly neutral solutions than in alkali or acidic solutions. Furthermore, A.C. impedance studies showed that the polarization resistances of oxide films formed in boric acid solutions were higher than those of films formed in acidic and alkali solutions. AES analysis revealed that boron content in the oxide films formed in acidic solution containing boric acid was lowest. Good agreement was obtained between the IGA/SCC inhibitory effect of boric acid and the formation of the stable oxide films containing boron.
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Rodrigues, Klin, Auribel Dos Santos, Hans Oskarsson, Szymon Jankowski, and Paul Ferm. "Smart Retarder for Cementing Systems with Accelerated Set and Gel Strength Properties with Potential for Improved Operational Safety." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/208074-ms.
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Abstract Cement retarders available in the market include the traditional lignosulfonates and synthetic copolymers. Commonly, lignosulfonates lack batch to batch reproducibility which hinders formulation consistency. Both lignosulfonates and synthetic polymers will retard the set of cement. However, their chemistry dictates that they also slow down setting time which increases waiting on cement time, thus increasing rig costs. This paper proposes a new smart cement retarder that overcomes these traditional negatives. A number of polymers were designed and synthesized aiming for a chemical able to retard the set of cement while also acting as an accelerator once the cement slurry was in place. These polymers were tested for cement retardation performance using a high-pressure high-temperature (HPHT) consistometer. Static Gel Strength Analyzers (SGSA) measurements were used to determine compressive strength development as well as static gel strength development while curing under downhole temperature and pressure conditions. The new smart cement retarder delivers cement retardation in the 125 - 350°F temperature range and can be used at higher temperatures using a co-retarder. This unique material delivers an accelerated set and attains 500 psi compressive strength very quickly which minimizes waiting on cement time. In addition, this new retarder builds static gel strength rapidly and minimizes gel transition time. Upscaling to field application, the top of the cementing column takes the longest to set. By having this inbuilt accelerator into the system, it allows the top of the column to set as fast as possible gaining the needed compressive strength at the weakest point of the cement column. This should ensure the quality of the cement job in comparison with conventional retarders with significant operating cost savings. The new smart cement retarder will simplify cementing formulations due to its flexibility in dosage range of the retarder within the slurry and improve the quality of the cement jobs. As a result, the proposed smart cement retarder can help with minimizing risk of failures during production and possibly improving safety.
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Montgomery, Justin, Timothy McNally, Jay Hunger, and Sreedhar Subramanian. "Evaluation of Lignosulfonate Based Retarders for Thickening Time as a Function of Dosage and Temperature." In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204327-ms.
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Abstract The retardation of class H Portland cement using lignosulfonates was investigated in the temperature range between 54°C and 153°C. Lignosulfonates with varying extent of modification was used in the study, and the optimum retarder dosage and temperature range to achieve desired thickening time was identified for different lignosulfonate types (non-modified, modified and highly modified). In general, a linear thickening response was observed at low retarder dosage, while a near exponential increase in thickening time response was observed at higher dosages. Defining the retarder dosage temperature relationship is essential for proper cement slurry design for securing desired placement of cement slurry. A significant finding is that the thickening time responses trend from near linear at low dosages, transitioning to near exponential at higher dosages. The observed results varied depending on the extent of modification performed on the lignosulfonate retarder. Pure lignosulfonate retarders produce optimal dosage response from 54°C to 97°C. Modified retarders work best in the range of 97°C to 118°C. While highly modified retarders perform best in the range of 118°C to 153°C. Defining the retarder dosage temperature relationship is essential for proper cement slurry design for securing desired placement of cement slurry.
Reports on the topic "Temperature Retarder"
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Lichter, Amnon, Gopi K. Podila, and Maria R. Davis. Identification of Genetic Determinants that Facilitate Development of B. cinerea at Low Temperature and its Postharvest Pathogenicity. United States Department of Agriculture, 2011. http://dx.doi.org/10.32747/2011.7592641.bard.
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Botrytis cinerea is the postharvest pathogen of many agricultural produce with table grapes, strawberries and tomatoes as major targets. The high efficiency with which B. cinerea causes disease on these produce during storage is attributed in part due to its exceptional ability to develop at very low temperature. Our major goal was to understand the genetic determinants which enable it to develop at low temperature. The specific research objectives were: 1. Identify expression pattern of genes in a coldenriched cDNA library. 2. Identify B. cinerea orthologs of cold-induced genes 3. Profile protein expression and secretion at low temperature on strawberry and grape supplemented media. 4. Test novel methods for the functional analysis of coldresponsive genes. Objective 1 was modified during the research because a microarray platform became available and it allowed us to probe the whole set of candidate genes according to the sequence of 2 strains of the fungus, BO5.10 and T4. The results of this experiment allowed us to validate some of our earlier observations which referred to genes which were the product of a SSH suppression-subtraction library. Before the microarray became available during 2008 we also analyzed the expression of 15 orthologs of cold-induced genes and some of these results were also validated by the microarray experiment. One of our goals was also to perform functional analysis of cold-induced genes. This goal was hampered for 3 years because current methodology for transformation with ‘protoplasts’ failed to deliver knockouts of bacteriordopsin-like (bR) gene which was our primary target for functional analysis. Consequently, we developed 2 alternative transformation platforms, one which involves an air-gun based technique and another which involves DNA injection into sclerotia. Both techniques show great promise and have been validated using different constructs. This contribution is likely to serve the scientific community in the near future. Using these technologies we generated gene knockout constructs of 2 genes and have tested there effect on survival of the fungus at low temperature. With reference to the bR genes our results show that it has a significant effect on mycelial growth of the B. cinerea and the mutants have retarded development at extreme conditions of ionic stress, osmotic stress and low temperature. Another gene of unknown function, HP1 is still under analysis. An ortholog of the yeast cold-induced gene, CCH1 which encodes a calcium tunnel and was shown to be cold-induced in B. cinerea was recently cloned and used to complement yeast mutants and rescue them from cold-sensitivity. One of the significant findings of the microarray study involves a T2 ribonuclease which was validated to be cold-induced by qPCR analysis. This and other genes will serve for future studies. In the frame of the study we also screened a population of 631 natural B. cinerea isolates for development at low temperature and have identified several strains with much higher and lower capacity to develop at low temperature. These strains are likely to be used in the future as candidates for further functional analysis. The major conclusions from the above research point to specific targets of cold-induced genes which are likely to play a role in cold tolerance. One of the most significant observations from the microarray study is that low temperature does not induce ‘general stress response in B. cinerea, which is in agreement to its exceptional capacity to develop at low temperature. Due to the tragic murder of the Co-PI Maria R. Davis and GopiPodila on Feb. 2010 it is impossible to deliver their contribution to the research. The information of the PI is that they failed to deliver objective 4 and none of the information which relates to objective 3 has been delivered to the PI before the murder or in a visit to U. Alabama during June, 2010. Therefore, this report is based solely on the IS data.