The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Lian Zhang - One of the best experts on this subject based on the ideXlab platform.
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xinjiang lignite ash slagging and flow under the weak Reducing Environment at high temperatures slag viscosity and its variation with ash type and addition of clay
Fuel, 2019Co-Authors: Baiqian Dai, Jie Zhao, Lian ZhangAbstract:Abstract In this study, five different ashes derived from Xinjiang lignite were tested for slagging at 1300–1400 °C in a weak Reducing Environment (1% CO in nitrogen), at different exposure time from 10 min to 2 h. The apparent viscosities for different slags were determined by using a modified inclined plane (M-IP) method with an inclination of 25° based on the slag travel length per unit mass. In particular, the variation on slag viscosity upon the blending of additives including clay and MgO was examined in detail. As have been confirmed, the slags derived from the original basic and neutral ashes start to flow from 1400 °C onwards. The viscosities calculated based on the M-IP method at 1400 °C are in the range from ∼1 Pa·s for neutral ash to ∼5 Pa·s for the basic ash slags. For both neutral and acidic slags, their viscosities calculated by the M-IP method show a good agreement with some of the existing empirical models that have been validated for high-rank coal slags. Upon the addition of 10 wt% clay, the viscosity of basic ash at 1300 °C was reduced to 1.53–1.71 Pa·s, demonstrating a comparable flow-ability and viscosity to that of the original ash at 1400 °C. The addition of MgO promotes the slag flow-ability and reduces the slag viscosity to a relatively small extent in comparison to clay. Instead of melting with other elements in the ash matrix to form slag, the discrete Mg grains are observed in the slag matrix. It could even partially react with the alumina plate. The precipitation of Mg may promote the slag flow-ability by alleviating the slag penetration into the alumina plane and the resultant friction between them. Additionally, the viscosities for both the original slags and those blended with clay decrease quickly upon the increase of the exposure time, substantiating a non-linear slagging propensity and hence, probably non-Newtonian property. A minimum exposure time of 40 min is essential to ensure these slags to settle down and reach their equilibrium viscosities in the M-IP method.
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Xinjiang lignite ash slagging and flow under the weak Reducing Environment at high temperatures – Slag viscosity and its variation with ash type and addition of clay
Fuel, 2019Co-Authors: Baiqian Dai, Jie Zhao, Lian ZhangAbstract:Abstract In this study, five different ashes derived from Xinjiang lignite were tested for slagging at 1300–1400 °C in a weak Reducing Environment (1% CO in nitrogen), at different exposure time from 10 min to 2 h. The apparent viscosities for different slags were determined by using a modified inclined plane (M-IP) method with an inclination of 25° based on the slag travel length per unit mass. In particular, the variation on slag viscosity upon the blending of additives including clay and MgO was examined in detail. As have been confirmed, the slags derived from the original basic and neutral ashes start to flow from 1400 °C onwards. The viscosities calculated based on the M-IP method at 1400 °C are in the range from ∼1 Pa·s for neutral ash to ∼5 Pa·s for the basic ash slags. For both neutral and acidic slags, their viscosities calculated by the M-IP method show a good agreement with some of the existing empirical models that have been validated for high-rank coal slags. Upon the addition of 10 wt% clay, the viscosity of basic ash at 1300 °C was reduced to 1.53–1.71 Pa·s, demonstrating a comparable flow-ability and viscosity to that of the original ash at 1400 °C. The addition of MgO promotes the slag flow-ability and reduces the slag viscosity to a relatively small extent in comparison to clay. Instead of melting with other elements in the ash matrix to form slag, the discrete Mg grains are observed in the slag matrix. It could even partially react with the alumina plate. The precipitation of Mg may promote the slag flow-ability by alleviating the slag penetration into the alumina plane and the resultant friction between them. Additionally, the viscosities for both the original slags and those blended with clay decrease quickly upon the increase of the exposure time, substantiating a non-linear slagging propensity and hence, probably non-Newtonian property. A minimum exposure time of 40 min is essential to ensure these slags to settle down and reach their equilibrium viscosities in the M-IP method.
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xinjiang lignite ash slagging and flowability under the weak Reducing Environment at 1300 c a new method to quantify slag flow velocity and its correlation with slag properties
Fuel Processing Technology, 2018Co-Authors: Baiqian Dai, Lian ZhangAbstract:Abstract In this study, a novel measurement method for the direct visualisation and quantification of lignite slag flowability has been established. The ash slagging was tested under a weak Reducing Environment (1% CO 2 in nitrogen) at temperature range from 1000 to 1300 °C to mimic a cyclone combustion furnace for the Chinese Xinjiang lignite. Five different ash samples with a broad variation on the basicity, i.e. base/acid ratio from 1.98 to 0.27, and their blends with up to 40 wt% clay were loaded on a 25°–inclined corundum substrate and exposed to the above-mentioned Reducing gases in a pre-heated horizontal furnace. The thermodynamic equilibrium software, FactSage 6.4 and typical viscosity equations were also employed to quantify the liquid fraction in each slag and its viscosity, respectively. Efforts were further made to correlate the calculated liquid fraction and viscosity of a slag and its flow velocity. As has been found, the neutral ash with the lowest ash fusion temperature is the only original ash sample that can melt and flow at 1300 °C without the use of clay additive, although its flow velocity is quite marginal. The addition of clay into basic ashes, at 8–10 wt% is able to improve the slag flow velocity by 6–7 times at 1300 °C. Both ash basicity and liquid fraction within an ash are critical in determining the slag flow velocity. However, neither has proven to be a sole and sufficient factor affecting the slag flowability. The slag viscosity is believed to be a key factor counter balancing the liquid fraction within a slag. This hypothesis was proven by the addition of 5–10 wt% MgO into a basic ash that decreased both the liquidus fraction and slag viscosity. Since the decrease on the slag viscosity (based on the calculation) was more remarkable than the liquidus fraction, the slag flow velocity was improved consequently. Apart from providing a new method to quantify slag flowability, this study also paved a direction for the future study focusing on lignite ash slag viscosity and modelling approach to correlate lignite slag properties and its flow velocity. A universal method has yet to be established for either of them.
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Xinjiang lignite ash slagging and flowability under the weak Reducing Environment at 1300 °C – A new method to quantify slag flow velocity and its correlation with slag properties
Fuel Processing Technology, 2018Co-Authors: Baiqian Dai, Lian ZhangAbstract:Abstract In this study, a novel measurement method for the direct visualisation and quantification of lignite slag flowability has been established. The ash slagging was tested under a weak Reducing Environment (1% CO 2 in nitrogen) at temperature range from 1000 to 1300 °C to mimic a cyclone combustion furnace for the Chinese Xinjiang lignite. Five different ash samples with a broad variation on the basicity, i.e. base/acid ratio from 1.98 to 0.27, and their blends with up to 40 wt% clay were loaded on a 25°–inclined corundum substrate and exposed to the above-mentioned Reducing gases in a pre-heated horizontal furnace. The thermodynamic equilibrium software, FactSage 6.4 and typical viscosity equations were also employed to quantify the liquid fraction in each slag and its viscosity, respectively. Efforts were further made to correlate the calculated liquid fraction and viscosity of a slag and its flow velocity. As has been found, the neutral ash with the lowest ash fusion temperature is the only original ash sample that can melt and flow at 1300 °C without the use of clay additive, although its flow velocity is quite marginal. The addition of clay into basic ashes, at 8–10 wt% is able to improve the slag flow velocity by 6–7 times at 1300 °C. Both ash basicity and liquid fraction within an ash are critical in determining the slag flow velocity. However, neither has proven to be a sole and sufficient factor affecting the slag flowability. The slag viscosity is believed to be a key factor counter balancing the liquid fraction within a slag. This hypothesis was proven by the addition of 5–10 wt% MgO into a basic ash that decreased both the liquidus fraction and slag viscosity. Since the decrease on the slag viscosity (based on the calculation) was more remarkable than the liquidus fraction, the slag flow velocity was improved consequently. Apart from providing a new method to quantify slag flowability, this study also paved a direction for the future study focusing on lignite ash slag viscosity and modelling approach to correlate lignite slag properties and its flow velocity. A universal method has yet to be established for either of them.
Baiqian Dai - One of the best experts on this subject based on the ideXlab platform.
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Bio-Slag High-Temperature Corrosion on an Alumina Refractory under the Reducing Environment
Energy & Fuels, 2021Co-Authors: Yan Zhou, Baiqian DaiAbstract:The alkali and alkaline earth metals in the biomass are one of the major challenges that restrict the biomass/low-rank-coal entrained-flow gasification in the way of ash slagging and corrosion. To ...
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xinjiang lignite ash slagging and flow under the weak Reducing Environment at high temperatures slag viscosity and its variation with ash type and addition of clay
Fuel, 2019Co-Authors: Baiqian Dai, Jie Zhao, Lian ZhangAbstract:Abstract In this study, five different ashes derived from Xinjiang lignite were tested for slagging at 1300–1400 °C in a weak Reducing Environment (1% CO in nitrogen), at different exposure time from 10 min to 2 h. The apparent viscosities for different slags were determined by using a modified inclined plane (M-IP) method with an inclination of 25° based on the slag travel length per unit mass. In particular, the variation on slag viscosity upon the blending of additives including clay and MgO was examined in detail. As have been confirmed, the slags derived from the original basic and neutral ashes start to flow from 1400 °C onwards. The viscosities calculated based on the M-IP method at 1400 °C are in the range from ∼1 Pa·s for neutral ash to ∼5 Pa·s for the basic ash slags. For both neutral and acidic slags, their viscosities calculated by the M-IP method show a good agreement with some of the existing empirical models that have been validated for high-rank coal slags. Upon the addition of 10 wt% clay, the viscosity of basic ash at 1300 °C was reduced to 1.53–1.71 Pa·s, demonstrating a comparable flow-ability and viscosity to that of the original ash at 1400 °C. The addition of MgO promotes the slag flow-ability and reduces the slag viscosity to a relatively small extent in comparison to clay. Instead of melting with other elements in the ash matrix to form slag, the discrete Mg grains are observed in the slag matrix. It could even partially react with the alumina plate. The precipitation of Mg may promote the slag flow-ability by alleviating the slag penetration into the alumina plane and the resultant friction between them. Additionally, the viscosities for both the original slags and those blended with clay decrease quickly upon the increase of the exposure time, substantiating a non-linear slagging propensity and hence, probably non-Newtonian property. A minimum exposure time of 40 min is essential to ensure these slags to settle down and reach their equilibrium viscosities in the M-IP method.
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Xinjiang lignite ash slagging and flow under the weak Reducing Environment at high temperatures – Slag viscosity and its variation with ash type and addition of clay
Fuel, 2019Co-Authors: Baiqian Dai, Jie Zhao, Lian ZhangAbstract:Abstract In this study, five different ashes derived from Xinjiang lignite were tested for slagging at 1300–1400 °C in a weak Reducing Environment (1% CO in nitrogen), at different exposure time from 10 min to 2 h. The apparent viscosities for different slags were determined by using a modified inclined plane (M-IP) method with an inclination of 25° based on the slag travel length per unit mass. In particular, the variation on slag viscosity upon the blending of additives including clay and MgO was examined in detail. As have been confirmed, the slags derived from the original basic and neutral ashes start to flow from 1400 °C onwards. The viscosities calculated based on the M-IP method at 1400 °C are in the range from ∼1 Pa·s for neutral ash to ∼5 Pa·s for the basic ash slags. For both neutral and acidic slags, their viscosities calculated by the M-IP method show a good agreement with some of the existing empirical models that have been validated for high-rank coal slags. Upon the addition of 10 wt% clay, the viscosity of basic ash at 1300 °C was reduced to 1.53–1.71 Pa·s, demonstrating a comparable flow-ability and viscosity to that of the original ash at 1400 °C. The addition of MgO promotes the slag flow-ability and reduces the slag viscosity to a relatively small extent in comparison to clay. Instead of melting with other elements in the ash matrix to form slag, the discrete Mg grains are observed in the slag matrix. It could even partially react with the alumina plate. The precipitation of Mg may promote the slag flow-ability by alleviating the slag penetration into the alumina plane and the resultant friction between them. Additionally, the viscosities for both the original slags and those blended with clay decrease quickly upon the increase of the exposure time, substantiating a non-linear slagging propensity and hence, probably non-Newtonian property. A minimum exposure time of 40 min is essential to ensure these slags to settle down and reach their equilibrium viscosities in the M-IP method.
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xinjiang lignite ash slagging and flowability under the weak Reducing Environment at 1300 c a new method to quantify slag flow velocity and its correlation with slag properties
Fuel Processing Technology, 2018Co-Authors: Baiqian Dai, Lian ZhangAbstract:Abstract In this study, a novel measurement method for the direct visualisation and quantification of lignite slag flowability has been established. The ash slagging was tested under a weak Reducing Environment (1% CO 2 in nitrogen) at temperature range from 1000 to 1300 °C to mimic a cyclone combustion furnace for the Chinese Xinjiang lignite. Five different ash samples with a broad variation on the basicity, i.e. base/acid ratio from 1.98 to 0.27, and their blends with up to 40 wt% clay were loaded on a 25°–inclined corundum substrate and exposed to the above-mentioned Reducing gases in a pre-heated horizontal furnace. The thermodynamic equilibrium software, FactSage 6.4 and typical viscosity equations were also employed to quantify the liquid fraction in each slag and its viscosity, respectively. Efforts were further made to correlate the calculated liquid fraction and viscosity of a slag and its flow velocity. As has been found, the neutral ash with the lowest ash fusion temperature is the only original ash sample that can melt and flow at 1300 °C without the use of clay additive, although its flow velocity is quite marginal. The addition of clay into basic ashes, at 8–10 wt% is able to improve the slag flow velocity by 6–7 times at 1300 °C. Both ash basicity and liquid fraction within an ash are critical in determining the slag flow velocity. However, neither has proven to be a sole and sufficient factor affecting the slag flowability. The slag viscosity is believed to be a key factor counter balancing the liquid fraction within a slag. This hypothesis was proven by the addition of 5–10 wt% MgO into a basic ash that decreased both the liquidus fraction and slag viscosity. Since the decrease on the slag viscosity (based on the calculation) was more remarkable than the liquidus fraction, the slag flow velocity was improved consequently. Apart from providing a new method to quantify slag flowability, this study also paved a direction for the future study focusing on lignite ash slag viscosity and modelling approach to correlate lignite slag properties and its flow velocity. A universal method has yet to be established for either of them.
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Xinjiang lignite ash slagging and flowability under the weak Reducing Environment at 1300 °C – A new method to quantify slag flow velocity and its correlation with slag properties
Fuel Processing Technology, 2018Co-Authors: Baiqian Dai, Lian ZhangAbstract:Abstract In this study, a novel measurement method for the direct visualisation and quantification of lignite slag flowability has been established. The ash slagging was tested under a weak Reducing Environment (1% CO 2 in nitrogen) at temperature range from 1000 to 1300 °C to mimic a cyclone combustion furnace for the Chinese Xinjiang lignite. Five different ash samples with a broad variation on the basicity, i.e. base/acid ratio from 1.98 to 0.27, and their blends with up to 40 wt% clay were loaded on a 25°–inclined corundum substrate and exposed to the above-mentioned Reducing gases in a pre-heated horizontal furnace. The thermodynamic equilibrium software, FactSage 6.4 and typical viscosity equations were also employed to quantify the liquid fraction in each slag and its viscosity, respectively. Efforts were further made to correlate the calculated liquid fraction and viscosity of a slag and its flow velocity. As has been found, the neutral ash with the lowest ash fusion temperature is the only original ash sample that can melt and flow at 1300 °C without the use of clay additive, although its flow velocity is quite marginal. The addition of clay into basic ashes, at 8–10 wt% is able to improve the slag flow velocity by 6–7 times at 1300 °C. Both ash basicity and liquid fraction within an ash are critical in determining the slag flow velocity. However, neither has proven to be a sole and sufficient factor affecting the slag flowability. The slag viscosity is believed to be a key factor counter balancing the liquid fraction within a slag. This hypothesis was proven by the addition of 5–10 wt% MgO into a basic ash that decreased both the liquidus fraction and slag viscosity. Since the decrease on the slag viscosity (based on the calculation) was more remarkable than the liquidus fraction, the slag flow velocity was improved consequently. Apart from providing a new method to quantify slag flowability, this study also paved a direction for the future study focusing on lignite ash slag viscosity and modelling approach to correlate lignite slag properties and its flow velocity. A universal method has yet to be established for either of them.
Jie Zhao - One of the best experts on this subject based on the ideXlab platform.
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xinjiang lignite ash slagging and flow under the weak Reducing Environment at high temperatures slag viscosity and its variation with ash type and addition of clay
Fuel, 2019Co-Authors: Baiqian Dai, Jie Zhao, Lian ZhangAbstract:Abstract In this study, five different ashes derived from Xinjiang lignite were tested for slagging at 1300–1400 °C in a weak Reducing Environment (1% CO in nitrogen), at different exposure time from 10 min to 2 h. The apparent viscosities for different slags were determined by using a modified inclined plane (M-IP) method with an inclination of 25° based on the slag travel length per unit mass. In particular, the variation on slag viscosity upon the blending of additives including clay and MgO was examined in detail. As have been confirmed, the slags derived from the original basic and neutral ashes start to flow from 1400 °C onwards. The viscosities calculated based on the M-IP method at 1400 °C are in the range from ∼1 Pa·s for neutral ash to ∼5 Pa·s for the basic ash slags. For both neutral and acidic slags, their viscosities calculated by the M-IP method show a good agreement with some of the existing empirical models that have been validated for high-rank coal slags. Upon the addition of 10 wt% clay, the viscosity of basic ash at 1300 °C was reduced to 1.53–1.71 Pa·s, demonstrating a comparable flow-ability and viscosity to that of the original ash at 1400 °C. The addition of MgO promotes the slag flow-ability and reduces the slag viscosity to a relatively small extent in comparison to clay. Instead of melting with other elements in the ash matrix to form slag, the discrete Mg grains are observed in the slag matrix. It could even partially react with the alumina plate. The precipitation of Mg may promote the slag flow-ability by alleviating the slag penetration into the alumina plane and the resultant friction between them. Additionally, the viscosities for both the original slags and those blended with clay decrease quickly upon the increase of the exposure time, substantiating a non-linear slagging propensity and hence, probably non-Newtonian property. A minimum exposure time of 40 min is essential to ensure these slags to settle down and reach their equilibrium viscosities in the M-IP method.
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Xinjiang lignite ash slagging and flow under the weak Reducing Environment at high temperatures – Slag viscosity and its variation with ash type and addition of clay
Fuel, 2019Co-Authors: Baiqian Dai, Jie Zhao, Lian ZhangAbstract:Abstract In this study, five different ashes derived from Xinjiang lignite were tested for slagging at 1300–1400 °C in a weak Reducing Environment (1% CO in nitrogen), at different exposure time from 10 min to 2 h. The apparent viscosities for different slags were determined by using a modified inclined plane (M-IP) method with an inclination of 25° based on the slag travel length per unit mass. In particular, the variation on slag viscosity upon the blending of additives including clay and MgO was examined in detail. As have been confirmed, the slags derived from the original basic and neutral ashes start to flow from 1400 °C onwards. The viscosities calculated based on the M-IP method at 1400 °C are in the range from ∼1 Pa·s for neutral ash to ∼5 Pa·s for the basic ash slags. For both neutral and acidic slags, their viscosities calculated by the M-IP method show a good agreement with some of the existing empirical models that have been validated for high-rank coal slags. Upon the addition of 10 wt% clay, the viscosity of basic ash at 1300 °C was reduced to 1.53–1.71 Pa·s, demonstrating a comparable flow-ability and viscosity to that of the original ash at 1400 °C. The addition of MgO promotes the slag flow-ability and reduces the slag viscosity to a relatively small extent in comparison to clay. Instead of melting with other elements in the ash matrix to form slag, the discrete Mg grains are observed in the slag matrix. It could even partially react with the alumina plate. The precipitation of Mg may promote the slag flow-ability by alleviating the slag penetration into the alumina plane and the resultant friction between them. Additionally, the viscosities for both the original slags and those blended with clay decrease quickly upon the increase of the exposure time, substantiating a non-linear slagging propensity and hence, probably non-Newtonian property. A minimum exposure time of 40 min is essential to ensure these slags to settle down and reach their equilibrium viscosities in the M-IP method.
Hidehito Urata - One of the best experts on this subject based on the ideXlab platform.
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Syntheses of prodrug-type phosphotriester oligonucleotides responsive to intracellular Reducing Environment for improvement of cell membrane permeability and nuclease resistance
Bioorganic & medicinal chemistry letters, 2017Co-Authors: Junsuke Hayashi, Yusuke Samezawa, Yosuke Ochi, Shun-ichi Wada, Hidehito UrataAbstract:We synthesized prodrug-type phosphotriester (PTE) oligonucleotides containing the six-membered cyclic disulfide moiety by using phosphoramidite chemistry. Prodrug-type oligonucleotides named "Reducing-Environment-Dependent Uncatalyzed Chemical Transforming (REDUCT) PTE oligonucleotides" were converted into natural oligonucleotides under cytosol-mimetic reductive condition. Furthermore, the REDUCT PTE oligonucleotides were robust to nuclease digestion and exhibited good cell membrane permeability.
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Gene silencing by 2'-O-methyldithiomethyl-modified siRNA, a prodrug-type siRNA responsive to Reducing Environment.
Bioorganic & medicinal chemistry letters, 2015Co-Authors: Yosuke Ochi, Junsuke Hayashi, Shun-ichi Wada, Osamu Nakagawa, Mieko Imai, Hidehito UrataAbstract:RNAs bearing various 2'-modifications have been synthesized in an effort to improve nuclease resistance. However, the gene silencing activity of small interfering RNAs (siRNAs) has been decreased or sometimes completely suppressed by the chemical modifications. We previously developed a post-synthetic approach for the synthesis of 2'-O-methyldithiomethyl-modified RNA, which can be converted into unmodified RNA under Reducing conditions, and named it Reducing-Environment-Dependent Uncatalyzed Chemical Transforming RNA (REDUCT RNA). Here, the gene silencing activity of REDUCT siRNA bearing 2'-O-methyldithiomethyl groups was evaluated. REDUCT siRNA showed more effective gene silencing than unmodified siRNA regardless of the modification site. This result suggests that REDUCT siRNA is converted into unmodified siRNA inside cells as a prodrug-type siRNA.
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A post-synthetic approach for the synthesis of 2′-O-methyldithiomethyl-modified oligonucleotides responsive to a Reducing Environment
Chemical communications (Cambridge England), 2013Co-Authors: Yosuke Ochi, Shun-ichi Wada, Osamu Nakagawa, Katsunori Sakaguchi, Hidehito UrataAbstract:Based on a novel concept, a Reducing-Environment-Dependent Uncatalyzed Chemical Transforming RNA, “REDUCT RNA”, we established a post-synthetic approach for the synthesis of 2′-O-methyldithiomethyl-modified oligonucleotides from 2′-O-(2,4,6-trimethoxybenzylthiomethyl)-oligonucleotides by treatment with dimethyl(methylthio)sulfonium tetrafluoroborate. 2′-O-methyldithiomethyl oligonucleotides were easily converted into 2′-hydroxy oligonucleotides under Reducing conditions, such as those found in the intracellular Environment.
Maheshwar Sharon - One of the best experts on this subject based on the ideXlab platform.
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role of Reducing Environment in the chemical growth of zinc selenide thin films
Materials Letters, 2013Co-Authors: L P Deshmukh, P C Pingale, S S Kamble, S A Lendave, S T Mane, B R Pirgonde, Madhuri Sharon, Maheshwar SharonAbstract:Abstract Chemical deposition of ZnSe (Zn/Se ratio, 0.57≤x≤0.99) thin films highlighting influence of Reducing Environment on the structural properties and surface morphology is presented. Hydrazine hydrate was used as a Reducing agent to initiate growth process and to reduce selenosulfate to Se2− ions that permits formation of non-stoichiometric ZnSe film layers. ZnSe films thus obtained are adherent, homogeneous and diffusely reflecting with light brown coloured tinge. These films were characterized through XRD, SEM, EDS and AFM techniques to reveal the structural and morphological informations. As-grown films are polycrystalline wurtzite with (1 0 1) preferred orientation. d-values change considerably whereas I/Imax is more or less constant. The average lattice parameters have similar trend of variation with Zn/Se ratio. Non-uniform distribution of spherical ZnSe crystallites was observed through SEM. The micrographs further indicated marginal agglomeration of crystallites forming globule like overgrowth. AFM studies spotlighted influence of Reducing Environment on the surface roughness of the films. The bulk ZnSe exhibits LO and TO phonon bands at 252 cm−1 and 205 cm−1 respectively as indicated by Raman studies. The optical band gap is decreased a little and is correlated to variation in the excess metallic Se-phase.