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Stephen T. Kempley - One of the best experts on this subject based on the ideXlab platform.
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Critical dependence of acetate thermal mattress on gel Activation Temperature
Archives of Disease in Childhood, 2007Co-Authors: Amy Carmichael, Sarah Mccullough, Stephen T. KempleyAbstract:Background: Sodium acetate gel mattresses provide an active method of warming patients through release of latent heat of crystallisation. They can be used as an adjunct to incubator care or as an exclusive heat source. Objective: To determine Activation Temperatures of the Transwarmer mattress needed to achieve plateau Temperatures of 38-42°C. Design and setting: In vitro testing of mattress Temperature. Methods and outcome measures: Transwarmer mattresses were activated at initial Temperatures ranging from 5 to 40°C. Mattress Temperature was recorded up to 4 h to determine peak and plateau Temperatures. Peak and plateau Temperatures achieved by the mattress were related to the initial starting Temperature. Results: The starting Temperature of the mattress was strongly correlated with peak and plateau Temperature (r=0.99, p
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Critical dependence of acetate thermal mattress on gel Activation Temperature.
Archives of disease in childhood. Fetal and neonatal edition, 2006Co-Authors: Amy Carmichael, Sarah Mccullough, Stephen T. KempleyAbstract:Background: Sodium acetate gel mattresses provide an active method of warming patients through release of latent heat of crystallisation. They can be used as an adjunct to incubator care or as an exclusive heat source. Objective: To determine Activation Temperatures of the Transwarmer mattress needed to achieve plateau Temperatures of 38–42°C. Design and setting: In vitro testing of mattress Temperature. Methods and outcome measures: Transwarmer mattresses were activated at initial Temperatures ranging from 5 to 40°C. Mattress Temperature was recorded up to 4 h to determine peak and plateau Temperatures. Peak and plateau Temperatures achieved by the mattress were related to the initial starting Temperature. Results: The starting Temperature of the mattress was strongly correlated with peak and plateau Temperature (r = 0.99, p Conclusions: Safe use of this device is critically dependent on gel Temperature at the point of Activation. To ensure warming of a hypothermic neonatal patient without running any risk of burns, the mattress should be activated with a gel Temperature between 19°C and 28°C.
Kulamani Parida - One of the best experts on this subject based on the ideXlab platform.
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Amine-modified titania–silica mixed oxides: 1. Effect of amine concentration and Activation Temperature towards epoxidation of cyclohexene
Catalysis Communications, 2005Co-Authors: Santosh Kumar Samantaray, Kulamani ParidaAbstract:Abstract Titania–silica mixed oxides with covalently bound 3-aminopropyl groups were prepared by keeping the amount of tetrabutylorthotitanate as fixed and varying the 3-aminopropyltriethoxy silane and tetraethylortho silicate precursors using sol–gel process. The samples are characterised to know the specific surface area, surface oxygen and hydrophilicity/hydrophobicity index. Epoxidation of cyclohexene with hydrogen peroxide is carried out over these catalysts as a function of amine concentration and Activation Temperature. The conversion of cyclohexene and selectivity towards cyclohexene oxide is directly correlated with the surface area as well as surface oxygen and hydrophobicity of the catalyst, respectively.
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Studies on anion-promoted titania: 3. Effect of concentration and source of phosphate ion, method of preparation, and Activation Temperature on redox, acid–base, textural and catalytic properties of titania
Journal of Molecular Catalysis A-chemical, 2000Co-Authors: Santosh Kumar Samantaray, Kulamani ParidaAbstract:The effect of phosphate concentration, source of phosphate ion, method of preparation and Activation Temperature on the redox, acid–base, textural, and catalytic properties of phosphated titania (PO 4 3− /TiO2) toward alcohol and cumene conversion reactions has been described. The characterisation of the catalyst was performed using X-ray powder diffraction (XRD), infra-red spectroscopy (IR), thermal analysis (TG–DTA), nitrogen adsorption–desorption methods, surface redox, acid–base and phosphate content by spectrophotometric method. TG–DTA and XRD patterns show that phosphate stabilises the anatase phase of TiO2 up to 1173 K and decreases its crystallite size. IR result shows that phosphate species strongly bound bidentately on TiO2 supports. Surface area is found to increase with the increase in phosphate content up to 7.5 wt.% loading and thereafter decreases. However, total acidity and the catalytic activity increases with the increase in phosphate content up to 10.0 wt.%. Phosphated samples (pH = 3) prepared using H3PO4 as the source of phosphate ion exhibit higher acidity than the samples (pH = 7) using H3PO4 and (NH4)3PO4, though all the three samples contain same amount of phosphate ion (10.0 wt.%). Among the 573, 773, 973, and 1173 K activated samples, the 573 K sample has shown maximum activity toward the above reactions. © 2001 Elsevier Science B.V. All rights reserved.
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Studies on PO43−/ZrO2: II. Effect of Phosphate Concentration and Activation Temperature on the Catalytic Properties of Zirconia
Journal of Colloid and Interface Science, 2000Co-Authors: P.k. Pattnayak, Kulamani ParidaAbstract:Abstract The effect of Activation Temperature and phosphate concentration on the catalytic properties of phosphated zirconia (PO43−/ZrO2) has been described. XRD patterns show that phosphate stabilizes the tetragonal phase of ZrO2 up to 1000°C but the crystallization Temperature is delayed with increases in the concentration of phosphate. Surface area and surface acidity of the samples increase with increases in the phosphate up to a certain concentration and decrease with further increases. The cumene cracking/dehydrogenation and 2-propanol conversion reactions are carried out to evaluate the catalytic properties of the samples. The nature of sites present on the samples has been determined and discussed by correlation of the concentration of phosphate, Activation Temperature, and activity and selectivity to a particular product. Among the 400, 500, and 600°C activated samples, the 500°C sample has shown maximum activity toward the above reactions.
G Suresh Babu - One of the best experts on this subject based on the ideXlab platform.
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CO2 utilization as a soft oxidant for the synthesis of styrene from ethylbenzene over Co3O4 supported on magnesium aluminate spinel: role of spinel Activation Temperature.
Scientific reports, 2020Co-Authors: Venkata Rao Madduluri, Ravi Kumar Marella, Marlia M Hanafiah, Sivarama Krishna Lakkaboyana, G Suresh BabuAbstract:Magnesium aluminate spinel (MgAl2O4) supported Co3O4 catalysts are synthesized and tested for the oxidative dehydrogenation (ODH) of ethylbenzene using CO2 as a soft oxidant. The effect of spinel calcination Temperature on the catalytic performance has been systematically investigated. With an increase in the Activation Temperature from 600 to 900 °C, the active presence of a single-phase MgAl2O4 spinel is observed. A catalyst series consisting of MgAl2O4 spinel with varying Co loadings (10-20 wt%) were prepared and systematically distinguished by ICP, XRD, BET, TPR, NH3-TPD, UV-Vis DRS, FT-IR, XPS, SEM, and TEM. Among the tested cobalt catalysts, 15Co/800MA sample derived by calcination of MgAl2O4 support at 800 °C exhibits the most excellent catalytic performance with the maximum ethylbenzene conversion (≥ 82%). Also, high yields of styrene (≥ 81%) could be consistently achieved on the same active catalyst. Further, the catalyst exhibited almost stable activity during 20 h time-on-stream with a slow decrease in the ethylbenzene conversion from 82 to 59%. However, the selectivity of styrene (98%) stayed almost constant during the reaction. Activation of the MgAl2O4 spinel at 800 °C facilitates a dramatic chemical homogeneity for the alignment of Co3O4 nanoparticles on the surface of the active catalyst. Moreover, the isolated Co3O4 clusters have a strong chemical/electronic interaction with the Mg2+ and Al3+ ions on the support perform a crucial role to achieve the maximum catalytic activity.
Amy Carmichael - One of the best experts on this subject based on the ideXlab platform.
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Critical dependence of acetate thermal mattress on gel Activation Temperature
Archives of Disease in Childhood, 2007Co-Authors: Amy Carmichael, Sarah Mccullough, Stephen T. KempleyAbstract:Background: Sodium acetate gel mattresses provide an active method of warming patients through release of latent heat of crystallisation. They can be used as an adjunct to incubator care or as an exclusive heat source. Objective: To determine Activation Temperatures of the Transwarmer mattress needed to achieve plateau Temperatures of 38-42°C. Design and setting: In vitro testing of mattress Temperature. Methods and outcome measures: Transwarmer mattresses were activated at initial Temperatures ranging from 5 to 40°C. Mattress Temperature was recorded up to 4 h to determine peak and plateau Temperatures. Peak and plateau Temperatures achieved by the mattress were related to the initial starting Temperature. Results: The starting Temperature of the mattress was strongly correlated with peak and plateau Temperature (r=0.99, p
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Critical dependence of acetate thermal mattress on gel Activation Temperature.
Archives of disease in childhood. Fetal and neonatal edition, 2006Co-Authors: Amy Carmichael, Sarah Mccullough, Stephen T. KempleyAbstract:Background: Sodium acetate gel mattresses provide an active method of warming patients through release of latent heat of crystallisation. They can be used as an adjunct to incubator care or as an exclusive heat source. Objective: To determine Activation Temperatures of the Transwarmer mattress needed to achieve plateau Temperatures of 38–42°C. Design and setting: In vitro testing of mattress Temperature. Methods and outcome measures: Transwarmer mattresses were activated at initial Temperatures ranging from 5 to 40°C. Mattress Temperature was recorded up to 4 h to determine peak and plateau Temperatures. Peak and plateau Temperatures achieved by the mattress were related to the initial starting Temperature. Results: The starting Temperature of the mattress was strongly correlated with peak and plateau Temperature (r = 0.99, p Conclusions: Safe use of this device is critically dependent on gel Temperature at the point of Activation. To ensure warming of a hypothermic neonatal patient without running any risk of burns, the mattress should be activated with a gel Temperature between 19°C and 28°C.
Moisés Frías - One of the best experts on this subject based on the ideXlab platform.
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Activation Temperature-mediated mineralogical transformations in slate quarry sludge: Pozzolanic properties
Construction and Building Materials, 2018Co-Authors: I.f. Sáez Del Bosque, Moisés Frías, M.i. Sánchez De Rojas, César MedinaAbstract:Abstract Ornamental stone quarries generate huge volumes of waste. The valorisation of such waste as possible additions (supplementary cementitious materials) to cement would contribute to the implementation of circular economy criteria in the construction industry. The study reported here constitutes a first-time analysis of the pozzolanicity and morphological and microstructural changes induced in slate quarry sludge by thermal Activation. The findings showed that thermal Activation enhanced waste pozzolanicity, which at later ages was slightly higher than found in granite sludge and lower than in silica fume and fired clay-based materials. According to the Frattini test, the materials resulting from blending 20% or less of this waste cannot be regarded as CEM IV pozzolanic cements. A microstructural study revealed the surface formation of C-S-H gels in the slate sludge/Ca(OH)2 system, which was more intense when the waste was activated. According to the statistical analysis performed, three factors -time, Activation Temperature and replacement ratio-, significantly affected slate sludge pozzolanicity.
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Mineralogical Evolution of Kaolin‐Based Drinking Water Treatment Waste for Use as Pozzolanic Material. The Effect of Activation Temperature
Journal of the American Ceramic Society, 2013Co-Authors: Moisés Frías, Raquel Vigil De La Villa, Rosario García, María Isabel Sánchez De Rojas, Trino A. BaloaAbstract:This study reports on exhaustive scientific research into the influence of the Activation Temperature of inert waste from drinking water treatment plants for use as supplementary cementing material in cements. The effect of Activation Temperature on the mineralogy of the reactive products resulting from pozzolanic activity and on the evolution of the hydrated phases formed during the pozzolanic reaction at 28 d of curing was analyzed with the assistance of different instrumental techniques such as X-ray fluorescence, X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopy. The results show that all the activated products (based on metakaolinite) presented high pozzolanic activity at all ages of the reaction (up to 90 d), although 600°C at 2 h are the recommended ideal Activation conditions from an energetic and economic viewpoint. The Activation Temperature (600°C–900°C for 2 h of retention) plays an important role in the reaction kinetics in activated drinking water waste/Ca(OH)2 systems. The hydrated phases identified under these Activation conditions were very similar, but with important differences in the crystalline aluminates phases content. Thus, the formation of stratlingite (C2ASH8) is favored at low Temperatures (
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Influence of Activation Temperature of kaolinite-based clay wastes on pozzolanic activity and kinetic parameters
Advances in Cement Research, 2010Co-Authors: Moisés Frías, O. Rodríguez, B. Nebreda, R. García, E. Villar-cociñaAbstract:It is well known that the transformation of some clay minerals into pozzolanic materials for the manufacture of Portland cements depends on the Activation conditions. In the current paper, a study was carried out to evaluate the effect of Activation Temperature in the range of 500–700°C on the characteristics of thermally activated clay wastes (ACWs). Different chemical, morphological, mineralogical and pozzolanic characteristics as well as kinetic parameter determinations were analysed in order to provide a complete study of the activated products and the viability of their use in the manufacture of blended cements. The results obtained showed that Activation Temperature plays a special role in the mineralogy of ACWs as well as their pozzolanic behaviour. Mineralogically, the ACWs were essentially formed from calcite and talc; kaolinite and chlorite were also identified depending on Activation conditions. The values of the kinetic parameters indicated different pozzolanic activity of the ACWs, mainly ove...
