The Experts below are selected from a list of 678 Experts worldwide ranked by ideXlab platform
U S Hareesh - One of the best experts on this subject based on the ideXlab platform.
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very low thermal conductivity in lanthanum phosphate zirconia ceramic nanocomposites processed using a precipitation Peptization synthetic approach
New Journal of Chemistry, 2016Co-Authors: Kottarathil Shijina, K G K Warrier, Sasidharan Sankar, Mohan Midhun, Meerankhan Firozkhan, Balagopal N Nair, U S HareeshAbstract:A wet chemical synthetic approach involving precipitation–Peptization mechanisms was successfully adopted for the development of LaPO4–ZrO2 nanocomposites with the ZrO2 content varying in the 5–20 wt% range. Stoichiometric lanthanum phosphate, formed as nanofibrils during the precipitation reaction with orthophosphoric acid, was subsequently transformed into nanorods of ∼10 nm width and 98% TD for the LaPO4–10 wt% ZrO2 composition upon sintering at 1600 °C. The addition of ZrO2 to LaPO4 impeded densification and grain growth inhibition of up to 50% was obtained for LaPO4–20 wt% ZrO2 nanocomposites. Furthermore, the nanocomposites indicated very low thermal conductivity values (1 W m−1 K−1) compared to single phase LaPO4. The non-reactivity of LaPO4 and ZrO2 at high temperatures and the low thermal conductivity values of LaPO4–ZrO2 render them effective for high temperature thermal insulation applications.
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temperature assisted acid catalyzed Peptization of tio2 facile sol gel approach for thermally stable anatase phase
RSC Advances, 2014Co-Authors: Vidya Kattoor, Venu Sreekala Smitha, Peer A Mohamed, U S Hareesh, K G K WarrierAbstract:High temperature stable, phase pure anatase has been successfully synthesized by temperature assisted acid catalyzed Peptization of hydrous titania through an aqueous sol–gel method. This facile method does not contain any metal or non metal dopants and is very effective in extending the anatase to rutile phase transformation by 200 °C. The temperature maintained during the Peptization process has a significant effect on the particle size and morphology of titanium dioxide. The sol synthesized by Peptization at 60 °C has the lowest particle size of 65.2 nm and after calcination at 800 °C, has a crystallite size of ∼53 nm. The relatively higher particle size of other samples is attributed to the aggregation of particles at respective Peptization temperatures. An optimum temperature of 60 °C is effective in minimising the aggregation behaviour of titania sol which further increases the photocatalytic activity. Titanium dioxide peptized at 60 °C has higher photocatalytic activity (∼86%) than the one peptized at 30 °C (∼74%) under UV-A exposure for 100 minutes with apparent rate constants 0.02 and 0.01 min−1 respectively. An increased anatase to rutile transformation temperature of 800 °C will be very useful in increasing the annealing especially in ceramic substrates. Thus highly photoactive nanocrystalline titania containing thermally stable anatase that can be used for high temperature photocatalytic applications has been synthesized.
B. Schaffer - One of the best experts on this subject based on the ideXlab platform.
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processed cheeses made with and without Peptization submicroscopic structure and thermodynamic characteristics
Journal of Thermal Analysis and Calorimetry, 2001Co-Authors: B. Schaffer, S Szakaly, D LőrinczyAbstract:The osteoporosis is regarded as a widespread disease all over the world. In the prevention therapy of this disease there is a primary role of the daily calcium intake with the proper Ca:P ratio (1:1–1:2). The primary source of Ca for people the dairy products are implied, from which only the processed cheeses have inadequate ratio of Ca:P. In cheeses processed without Peptization developed in the Hungarian Dairy Research Institute (HDRI) the Ca:P ratio meets the requirements (1.5:1), moreover these products can be enriched with Ca. In this study we used both processing technologies. The electronmicroscopic photographs demonstrate the differences clearly. The traditionally processed cheese (with Peptization) has a 'spongy’ structure well known from literature, while a space-net can be seen resulting from the casein-filamentous hydrocolloid interaction in the structure of heat-treated cheese without Peptization. DSC curves are the same in the temperature range 0–40°C, showing endotherm melting process in two well-distinguished temperature interval (0–20 and 22–40°C). They are different in the temperature interval 40–100°C: in the case of processed cheese with Peptization the gel-sol transformation gives a higher endotherm peak in a narrow temperature range, while for heat-treated cheese without Peptization this temperature range is wider with a lower endotherm peak. Both electronmicroscopic and DSC investigations have proved that contrary to the traditionally processed cheese where the structure is formed by the linked peptized protein, in the heat- processed cheese without Peptization the frame-forming element is the huge hydrocolloid molecule interacted with the protein. The enthalpy change is substantially lower at the disintegration of the latter structure.
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processed cheeses made with and without Peptization submicroscopic structure and thermodynamic characteristics
Journal of Thermal Analysis and Calorimetry, 2001Co-Authors: B. Schaffer, S Szakaly, D LőrinczyAbstract:Abstract The osteoporosis is regarded as a widespread disease all over the world. In the prevention therapy of this disease there is a primary role of the daily calcium intake with the proper Ca:P ratio (1:1–1:2). The primary source of Ca for people the dairy products are implied, from which only the processed cheeses have inadequate ratio of Ca:P. In cheeses processed without Peptization developed in the Hungarian Dairy Research Institute (HDRI) the Ca:P ratio meets the requirements (1.5:1), moreover these products can be enriched with Ca. In this study we used both processing technologies. The electronmicroscopic photographs demonstrate the differences clearly. The traditionally processed cheese (with Peptization) has a 'spongy’ structure well known from literature, while a space-net can be seen resulting from the casein-filamentous hydrocolloid interaction in the structure of heat-treated cheese without Peptization. DSC curves are the same in the temperature range 0–40C, showing endotherm melting proc...
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dsc and electronmicroscopic investigation of dispersion type processed cheeses made without Peptization
Journal of Thermal Analysis and Calorimetry, 1999Co-Authors: B. Schaffer, D Lőrinczy, Joseph BelagyiAbstract:In contrast with the traditional method of cheese processing, where Ca breaks down from the protein chain and protein is peptized, a new technology has been elaborated, during which cheese is dispersed without phosphate-containing processing salt, when the gel is formed by plant hydrocolloids. Raw material of constant composition was processed with a phosphate-containing salt or in the presence of hydrocolloids. Thermodynamic processes occurring during the processing and in the end-products were examined by an ultra-sensitive micro DSC method. The structures of end-products were also investigated by electronmicroscopy. The temperature ranges of the endothermal processes indicating the transformations of protein and hydrocolloids can be distinguished: 81-90°C for Peptization processing and 61-72°C for processing without Peptization. The differences are less in the end-products: 75-87°C in traditional processed cheese and 68-74°C in processed cheeses made without Peptization. In contrast with the spongy structure of traditional processed cheeses consisting of peptized proteins, processed cheeses made without Peptization involve structure-forming elements created by the interaction of linear macromolecules of hydrocolloids and cheese proteins.
K G K Warrier - One of the best experts on this subject based on the ideXlab platform.
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very low thermal conductivity in lanthanum phosphate zirconia ceramic nanocomposites processed using a precipitation Peptization synthetic approach
New Journal of Chemistry, 2016Co-Authors: Kottarathil Shijina, K G K Warrier, Sasidharan Sankar, Mohan Midhun, Meerankhan Firozkhan, Balagopal N Nair, U S HareeshAbstract:A wet chemical synthetic approach involving precipitation–Peptization mechanisms was successfully adopted for the development of LaPO4–ZrO2 nanocomposites with the ZrO2 content varying in the 5–20 wt% range. Stoichiometric lanthanum phosphate, formed as nanofibrils during the precipitation reaction with orthophosphoric acid, was subsequently transformed into nanorods of ∼10 nm width and 98% TD for the LaPO4–10 wt% ZrO2 composition upon sintering at 1600 °C. The addition of ZrO2 to LaPO4 impeded densification and grain growth inhibition of up to 50% was obtained for LaPO4–20 wt% ZrO2 nanocomposites. Furthermore, the nanocomposites indicated very low thermal conductivity values (1 W m−1 K−1) compared to single phase LaPO4. The non-reactivity of LaPO4 and ZrO2 at high temperatures and the low thermal conductivity values of LaPO4–ZrO2 render them effective for high temperature thermal insulation applications.
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temperature assisted acid catalyzed Peptization of tio2 facile sol gel approach for thermally stable anatase phase
RSC Advances, 2014Co-Authors: Vidya Kattoor, Venu Sreekala Smitha, Peer A Mohamed, U S Hareesh, K G K WarrierAbstract:High temperature stable, phase pure anatase has been successfully synthesized by temperature assisted acid catalyzed Peptization of hydrous titania through an aqueous sol–gel method. This facile method does not contain any metal or non metal dopants and is very effective in extending the anatase to rutile phase transformation by 200 °C. The temperature maintained during the Peptization process has a significant effect on the particle size and morphology of titanium dioxide. The sol synthesized by Peptization at 60 °C has the lowest particle size of 65.2 nm and after calcination at 800 °C, has a crystallite size of ∼53 nm. The relatively higher particle size of other samples is attributed to the aggregation of particles at respective Peptization temperatures. An optimum temperature of 60 °C is effective in minimising the aggregation behaviour of titania sol which further increases the photocatalytic activity. Titanium dioxide peptized at 60 °C has higher photocatalytic activity (∼86%) than the one peptized at 30 °C (∼74%) under UV-A exposure for 100 minutes with apparent rate constants 0.02 and 0.01 min−1 respectively. An increased anatase to rutile transformation temperature of 800 °C will be very useful in increasing the annealing especially in ceramic substrates. Thus highly photoactive nanocrystalline titania containing thermally stable anatase that can be used for high temperature photocatalytic applications has been synthesized.
D Lőrinczy - One of the best experts on this subject based on the ideXlab platform.
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processed cheeses made with and without Peptization submicroscopic structure and thermodynamic characteristics
Journal of Thermal Analysis and Calorimetry, 2001Co-Authors: B. Schaffer, S Szakaly, D LőrinczyAbstract:Abstract The osteoporosis is regarded as a widespread disease all over the world. In the prevention therapy of this disease there is a primary role of the daily calcium intake with the proper Ca:P ratio (1:1–1:2). The primary source of Ca for people the dairy products are implied, from which only the processed cheeses have inadequate ratio of Ca:P. In cheeses processed without Peptization developed in the Hungarian Dairy Research Institute (HDRI) the Ca:P ratio meets the requirements (1.5:1), moreover these products can be enriched with Ca. In this study we used both processing technologies. The electronmicroscopic photographs demonstrate the differences clearly. The traditionally processed cheese (with Peptization) has a 'spongy’ structure well known from literature, while a space-net can be seen resulting from the casein-filamentous hydrocolloid interaction in the structure of heat-treated cheese without Peptization. DSC curves are the same in the temperature range 0–40C, showing endotherm melting proc...
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dsc and electronmicroscopic investigation of dispersion type processed cheeses made without Peptization
Journal of Thermal Analysis and Calorimetry, 1999Co-Authors: B. Schaffer, D Lőrinczy, Joseph BelagyiAbstract:In contrast with the traditional method of cheese processing, where Ca breaks down from the protein chain and protein is peptized, a new technology has been elaborated, during which cheese is dispersed without phosphate-containing processing salt, when the gel is formed by plant hydrocolloids. Raw material of constant composition was processed with a phosphate-containing salt or in the presence of hydrocolloids. Thermodynamic processes occurring during the processing and in the end-products were examined by an ultra-sensitive micro DSC method. The structures of end-products were also investigated by electronmicroscopy. The temperature ranges of the endothermal processes indicating the transformations of protein and hydrocolloids can be distinguished: 81-90°C for Peptization processing and 61-72°C for processing without Peptization. The differences are less in the end-products: 75-87°C in traditional processed cheese and 68-74°C in processed cheeses made without Peptization. In contrast with the spongy structure of traditional processed cheeses consisting of peptized proteins, processed cheeses made without Peptization involve structure-forming elements created by the interaction of linear macromolecules of hydrocolloids and cheese proteins.
Kottarathil Shijina - One of the best experts on this subject based on the ideXlab platform.
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very low thermal conductivity in lanthanum phosphate zirconia ceramic nanocomposites processed using a precipitation Peptization synthetic approach
New Journal of Chemistry, 2016Co-Authors: Kottarathil Shijina, K G K Warrier, Sasidharan Sankar, Mohan Midhun, Meerankhan Firozkhan, Balagopal N Nair, U S HareeshAbstract:A wet chemical synthetic approach involving precipitation–Peptization mechanisms was successfully adopted for the development of LaPO4–ZrO2 nanocomposites with the ZrO2 content varying in the 5–20 wt% range. Stoichiometric lanthanum phosphate, formed as nanofibrils during the precipitation reaction with orthophosphoric acid, was subsequently transformed into nanorods of ∼10 nm width and 98% TD for the LaPO4–10 wt% ZrO2 composition upon sintering at 1600 °C. The addition of ZrO2 to LaPO4 impeded densification and grain growth inhibition of up to 50% was obtained for LaPO4–20 wt% ZrO2 nanocomposites. Furthermore, the nanocomposites indicated very low thermal conductivity values (1 W m−1 K−1) compared to single phase LaPO4. The non-reactivity of LaPO4 and ZrO2 at high temperatures and the low thermal conductivity values of LaPO4–ZrO2 render them effective for high temperature thermal insulation applications.