The synthesis for glasses series xFe<sub>2</sub>O<sub>3</sub>-(45-x)PbO-55P<sub>2</sub>O<sub>5</sub>, (with 0 ≤ x ≤ 20;mol%) carried out in a temperature (1050 ± ...The synthesis for glasses series xFe<sub>2</sub>O<sub>3</sub>-(45-x)PbO-55P<sub>2</sub>O<sub>5</sub>, (with 0 ≤ x ≤ 20;mol%) carried out in a temperature (1050 ± 10)°C, leads to obtaining transparent glasses, brown in color and with a non-hygroscopic appearance. The study of glasses dissolution rate, immersed in distilled water at 90°C for 24 days, indicates a considerable chemical durability. The increase in the Fe<sub>2</sub>O<sub>3</sub> content in the vitreous network to the detriment of PbO is a favorable factor for the chemical durability improvement. Different techniques have been used such as X-ray diffraction, infrared spectroscopy, DSC, SEM and density for the study of these glasses. These techniques have led to establish correlations between chemical and structural properties. Thus the results obtained confirmed the creation of P-O-M bonds (M = Pb, Fe) with a strongly covalent nature to the detriment of the hydrated P-O-P bonds and led to the formation, mainly, of pyrophosphate groups. The low melting point of Pb-O makes it possible to play an important role, at the same time, on the viscosity, on the equilibrium between the vitreous bath and the crystallites formed. The dissolution rate obtained is 100 times smaller than that of silicate glasses used as an alternative form for the vitrification of radioactive waste.展开更多
The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks（ANN）. Herein hard rock brittleness is defined using Yagiz＇method. A pre...The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks（ANN）. Herein hard rock brittleness is defined using Yagiz＇method. A predictive model is developed using a comprehensive database compiled from 30 years＇ worth of rock tests at the Earth Mechanics Institute（EMI）, Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.展开更多
In this paper, a new sensorless interior permanent magnet synchronous motor （IPMSM） drives method with extended Kalman filter （EKF） for speed, rotor position and load torque estimation is proposed. The direct torq...In this paper, a new sensorless interior permanent magnet synchronous motor （IPMSM） drives method with extended Kalman filter （EKF） for speed, rotor position and load torque estimation is proposed. The direct torque control （DTC） technique for permanem magnet synchronous motor （PMSM） is receiving increasing attention due to the important advantages of the low dependence on motor parameters when compared with other motor control techniques. The Kalman filter is an observer for linear and non-linear systems and is based on the stochastic intromission, in others words, noise. The PMSM is fed by an indirect power electronic converter which is controlled by a sliding mode technique. The simulation tests performed for different operating condi- tions have confirmed the robustness of the overall system; and it is shown that the sliding mode technique has successfully minimized the different harmonics introduced by the line converter.展开更多
The structure and chemical durability in the vitreous part of the system 60P2O5-2Cr2O3-xFe2O3-(38 - x)Na2O phosphate glasses (with 3 ≤ x ≤ 33 mol%) were investigated using various techniques such as IR spectroscopy,...The structure and chemical durability in the vitreous part of the system 60P2O5-2Cr2O3-xFe2O3-(38 - x)Na2O phosphate glasses (with 3 ≤ x ≤ 33 mol%) were investigated using various techniques such as IR spectroscopy, X-ray diffraction and M?ssbauer spectroscopy. The presence of Cr2O3 and the increase of Fe2O3 at the expense of Na2O in the glass network lead to a large number of covalent and rigid Fe-O-P and Cr-O-P bonds. The infrared and XRD spectra indicate a radical change of structure and show that the increase of the Fe2O3 content favors the depolymerization of the vitreous network towards pyrophosphate chains. The presence of Cr2O3 in the glass seems to favor the covalent Cr-O-P bonds linked to the most probable cyclic metaphosphate chains. However, when the Fe2O3 content increases (≥23 mol%), its impact on the glass network is stronger than that of Cr2O3. The infrared and XRD spectra indicate a radical change of structure and show that the increase in Fe2O3 content favors the depolymerization of the vitreous network to short pyrophosphate chains. The results of M?ssbauer spectroscopy indicate the presence of both Fe (III) and Fe (II) ions which occupied more or less deformed octahedral sites. The growth of the glass transition temperature (Tg) with the increase of the iron oxide in the vitreous network, leads to an improvement of the glass rigidity. This explains the decrease of the ionic radius of the iron and the reinforcement of the interconnection of the chains of vitreous networks. The structure of sodium-chromium-iron phosphate glasses can be considered largely as pyrophosphate units linked to ferric and ferrous ions in octahedral or deformed octahedral coordination. The dissolution rate is 200 times lower than that of the silicate glasses.展开更多
Understanding the situation of sign language(SL)and its history is essential to comprehend the role of sign language interpreter better.It has often implied fundamental questions that refer to the identity constructio...Understanding the situation of sign language(SL)and its history is essential to comprehend the role of sign language interpreter better.It has often implied fundamental questions that refer to the identity construction of the person,his/her attachment to a linguistic community and the place of this community in the current social scheme.Sign language is like any other human languages;it spontaneously develops through deaf communities using this language and without external interference from hearing persons.All living human languages,whether spoken or signed,are characterised by the multiplicity,diversity,and the evolving nature of their vocabulary and this is what determines and proves of the richness of a language.Those who interpret from spoken to sign language are usually referred to as“sign language interpreters”and“deaf interpreters”,but both terms are unsatisfactory because both apply only to the language or community to which they serve.This article will try to shed light on the origins of sign language as well as the emergence of sign language interpreters as key players in an everlasting debate round the deaf and the deaf rights throughout nearly three centuries.展开更多
The impact of climate change on sea level has received a great deal of attention by scientists worldwide. In this context, the problem of sea levels on global and regional scales have been analyzed in a number of stud...The impact of climate change on sea level has received a great deal of attention by scientists worldwide. In this context, the problem of sea levels on global and regional scales have been analyzed in a number of studies based on tide gauges observations and satellite altimetry measurements. This study focuses on trend estimates from 18 high-quality tide gauge stations along the Mediterranean Sea coast. The seasonal Mann-Kendall test was run at a 5% significance level for each of the 18 stations for the period of 1993-2015 (satellite altimetry era). The results of this test indicate that the trends for 17 stations were statistically significant and showed an increase (no significant trend was observed only at one station). The rates of sea level change for the 17 stations that exhibit significant trends, estimated using seasonal Sen's approach, range after correction for Vertical Land Motion (VLM) from 1.48 to 8.72 mm/a for the period 1993-2015. Furthermore, the magnitude of change at the location of each tide gauge station was estimated using the satellite altimetry measurements. Thus, the results obtained agree with those from the tide-gauge data analysis.展开更多
The bioactive triterpenoid 3-oxo-6-β-hydroxy-β-amyrin(1)has been isolated from multiple plant sources.In this study,chloroform fraction of Pistacia integerrima extract was processed for the isolation of the compound...The bioactive triterpenoid 3-oxo-6-β-hydroxy-β-amyrin(1)has been isolated from multiple plant sources.In this study,chloroform fraction of Pistacia integerrima extract was processed for the isolation of the compound.The compound identity was confirmed by advanced spectroscopy technique.X-ray crystallography was applied for molecular structure confirmation.In addition,compound 1 was screen for its activity on reversal of MDR(multidrug resistance)mediated by P-gp(P-glycoprotein).This was accomplished by using rhodamine123 exclusion on multidrug-resistant human ABCB1 gene transfected mouse T-lymphoma cell line.Outcomes revealed that MDR reversing effect was comparable to verapamil as positive control in vitro.Treatment of TPA-induced tumor promotion with 3-oxo-6β-hydroxy-β-amyrin led to reduction in the applied anti-tumor promotion experiment.The chemo-preventive effect of 3-oxo-6β-hydroxy-β-amyrin was comparable to curcumin as positive control based on the reduction of immediate early tumor antigen expression.Molecular docking by applying Autodock Vina 1 and i-GEMDOCK v 2.1 tools indicated that compound 1 gives good docking results,as determined by their fitness score and specificity.Moreover,results showed that compound 1 isolated from Pistacia integerrima precisely attached to a region where co-crystallized ligand for receptor previously existed.Our findings may explain the use of Pistacia integerrima plant extracts as an anticancer agent in folk medicine.展开更多
Proteintyrosine phosphatase 1B(PTP1B)inhibitionis consideredas a potentialtherapeuticfor the treatmentof cancer,type2 diabetes,andobesity.Inour presentwork,weinvestigatedtheanti-diabeticpotentialof8-hydroxydiospyrin(8...Proteintyrosine phosphatase 1B(PTP1B)inhibitionis consideredas a potentialtherapeuticfor the treatmentof cancer,type2 diabetes,andobesity.Inour presentwork,weinvestigatedtheanti-diabeticpotentialof8-hydroxydiospyrin(8-HDN)from D.lotus against the PTP1B enzyme.It showed significant inhibitory activity of PTP1B with an IC 50 value of 18.37±0.02μM.A detailed molecular docking study was carried out to analyze the binding orientation,binding energy,and mechanism of inhibition.A comparative investigation of 8-HDN in the catalytic,as well as the allosteric site of PTP1B,was performed.Binding energy data showed that compound 8-HDN is more selective for the allosteric site and hence avoids the problems associated with catalytic site inhibition.The inhibition mechanism of 8-HDN can be further investigated as an active lead compound against PTP1B by using in vitro and in vivo models.展开更多
The in-soil biodegradation of Stipa tenacissima(alfa)leaves was examined.Non-linear mechanical testing was performed at various biodegradation stages.Tensile strength,loading and unloading Young’s moduli and dissipat...The in-soil biodegradation of Stipa tenacissima(alfa)leaves was examined.Non-linear mechanical testing was performed at various biodegradation stages.Tensile strength,loading and unloading Young’s moduli and dissipation energy decreased with the burial time,whereas plasticity increased.Field-emission scanning electron microscopy(FE-SEM)showed that the fracture cracks propagated in the longitudinal direction in the raw material,resulting in a fracture mode consisting of a mixture of middle lamella delamination and fiber pull-out.In contrast,the cracks were perpendicular to the stem axis in the biodegraded material,demonstrating an important strength loss of the load-bearing fibers.This strength loss was correlated with rapid cellulose degradation.A novel X-ray diffraction(XRD)model was implemented in order to take into account anisotropic size broadening.For the first time,XRD demonstrated the action of biodegradation on unrefined plant tissues under quasi in-situ conditions.Biodegradation induced a progressive loss of crystalline cellulose accompanied with anisotropic crystallite thinning.展开更多
In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and du...In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and due to the European Council Directives on the reuse,recycling and valorization of car components and materials.The aim of our study is to investigate biochemical,physicochemical,and mechanical properties of technical flax fibers to evaluate the impact of transformation processes(scutching,hackling,and homogenization)on final properties of associated composite materials.Different chemical analysis such as Van Soest(biochemical fraction measurement),FTIR(Fourier Transform InfraRed spectroscopy),and XRD(X-ray diffraction)were carried out on different process modalities and show that there is no significant difference in terms of biochemical fraction and crystallinity index.By the same token,mechanical behavior shows that Young’s modulus is not affected by the transformation process.This result is also observed for thermal behavior.The results highlight the fact that the transformation processes of technical fibers do not really affect their physicochemical and mechanical performances.展开更多
The main purpose of this study is to highlight, on the basis of statistical tests, the significant long-term changes of the Mediterranean Sea level, through the analysis of historical tide gauge records. In this frame...The main purpose of this study is to highlight, on the basis of statistical tests, the significant long-term changes of the Mediterranean Sea level, through the analysis of historical tide gauge records. In this framework, 14 tide gauge monthly series selected from the Permanent Service of the Mean Sea Level(PSMSL) database were used. The search for the presence or not of trends within these series, that have a temporal coverage from 59 to 142 years, was carried out using the Mann-Kendall test and the Sen’s slope estimator. The obtained results show that the Split Rt Marjana series are the only ones which does not exhibit a significant trend. The other 13 series show significant increasing trends. This result seems sufficient to suppose the presence, in the past century, of a new climatic phase on the scale of the Mediterranean basin, where the rising sea level is one of the consequences.展开更多
文摘The synthesis for glasses series xFe<sub>2</sub>O<sub>3</sub>-(45-x)PbO-55P<sub>2</sub>O<sub>5</sub>, (with 0 ≤ x ≤ 20;mol%) carried out in a temperature (1050 ± 10)°C, leads to obtaining transparent glasses, brown in color and with a non-hygroscopic appearance. The study of glasses dissolution rate, immersed in distilled water at 90°C for 24 days, indicates a considerable chemical durability. The increase in the Fe<sub>2</sub>O<sub>3</sub> content in the vitreous network to the detriment of PbO is a favorable factor for the chemical durability improvement. Different techniques have been used such as X-ray diffraction, infrared spectroscopy, DSC, SEM and density for the study of these glasses. These techniques have led to establish correlations between chemical and structural properties. Thus the results obtained confirmed the creation of P-O-M bonds (M = Pb, Fe) with a strongly covalent nature to the detriment of the hydrated P-O-P bonds and led to the formation, mainly, of pyrophosphate groups. The low melting point of Pb-O makes it possible to play an important role, at the same time, on the viscosity, on the equilibrium between the vitreous bath and the crystallites formed. The dissolution rate obtained is 100 times smaller than that of silicate glasses used as an alternative form for the vitrification of radioactive waste.
文摘The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks（ANN）. Herein hard rock brittleness is defined using Yagiz＇method. A predictive model is developed using a comprehensive database compiled from 30 years＇ worth of rock tests at the Earth Mechanics Institute（EMI）, Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.
文摘In this paper, a new sensorless interior permanent magnet synchronous motor （IPMSM） drives method with extended Kalman filter （EKF） for speed, rotor position and load torque estimation is proposed. The direct torque control （DTC） technique for permanem magnet synchronous motor （PMSM） is receiving increasing attention due to the important advantages of the low dependence on motor parameters when compared with other motor control techniques. The Kalman filter is an observer for linear and non-linear systems and is based on the stochastic intromission, in others words, noise. The PMSM is fed by an indirect power electronic converter which is controlled by a sliding mode technique. The simulation tests performed for different operating condi- tions have confirmed the robustness of the overall system; and it is shown that the sliding mode technique has successfully minimized the different harmonics introduced by the line converter.
文摘The structure and chemical durability in the vitreous part of the system 60P2O5-2Cr2O3-xFe2O3-(38 - x)Na2O phosphate glasses (with 3 ≤ x ≤ 33 mol%) were investigated using various techniques such as IR spectroscopy, X-ray diffraction and M?ssbauer spectroscopy. The presence of Cr2O3 and the increase of Fe2O3 at the expense of Na2O in the glass network lead to a large number of covalent and rigid Fe-O-P and Cr-O-P bonds. The infrared and XRD spectra indicate a radical change of structure and show that the increase of the Fe2O3 content favors the depolymerization of the vitreous network towards pyrophosphate chains. The presence of Cr2O3 in the glass seems to favor the covalent Cr-O-P bonds linked to the most probable cyclic metaphosphate chains. However, when the Fe2O3 content increases (≥23 mol%), its impact on the glass network is stronger than that of Cr2O3. The infrared and XRD spectra indicate a radical change of structure and show that the increase in Fe2O3 content favors the depolymerization of the vitreous network to short pyrophosphate chains. The results of M?ssbauer spectroscopy indicate the presence of both Fe (III) and Fe (II) ions which occupied more or less deformed octahedral sites. The growth of the glass transition temperature (Tg) with the increase of the iron oxide in the vitreous network, leads to an improvement of the glass rigidity. This explains the decrease of the ionic radius of the iron and the reinforcement of the interconnection of the chains of vitreous networks. The structure of sodium-chromium-iron phosphate glasses can be considered largely as pyrophosphate units linked to ferric and ferrous ions in octahedral or deformed octahedral coordination. The dissolution rate is 200 times lower than that of the silicate glasses.
文摘Understanding the situation of sign language(SL)and its history is essential to comprehend the role of sign language interpreter better.It has often implied fundamental questions that refer to the identity construction of the person,his/her attachment to a linguistic community and the place of this community in the current social scheme.Sign language is like any other human languages;it spontaneously develops through deaf communities using this language and without external interference from hearing persons.All living human languages,whether spoken or signed,are characterised by the multiplicity,diversity,and the evolving nature of their vocabulary and this is what determines and proves of the richness of a language.Those who interpret from spoken to sign language are usually referred to as“sign language interpreters”and“deaf interpreters”,but both terms are unsatisfactory because both apply only to the language or community to which they serve.This article will try to shed light on the origins of sign language as well as the emergence of sign language interpreters as key players in an everlasting debate round the deaf and the deaf rights throughout nearly three centuries.
文摘The impact of climate change on sea level has received a great deal of attention by scientists worldwide. In this context, the problem of sea levels on global and regional scales have been analyzed in a number of studies based on tide gauges observations and satellite altimetry measurements. This study focuses on trend estimates from 18 high-quality tide gauge stations along the Mediterranean Sea coast. The seasonal Mann-Kendall test was run at a 5% significance level for each of the 18 stations for the period of 1993-2015 (satellite altimetry era). The results of this test indicate that the trends for 17 stations were statistically significant and showed an increase (no significant trend was observed only at one station). The rates of sea level change for the 17 stations that exhibit significant trends, estimated using seasonal Sen's approach, range after correction for Vertical Land Motion (VLM) from 1.48 to 8.72 mm/a for the period 1993-2015. Furthermore, the magnitude of change at the location of each tide gauge station was estimated using the satellite altimetry measurements. Thus, the results obtained agree with those from the tide-gauge data analysis.
基金funded by Higher Education commission,Pakistan(HEC)(Grant No.NRPU649).
文摘The bioactive triterpenoid 3-oxo-6-β-hydroxy-β-amyrin(1)has been isolated from multiple plant sources.In this study,chloroform fraction of Pistacia integerrima extract was processed for the isolation of the compound.The compound identity was confirmed by advanced spectroscopy technique.X-ray crystallography was applied for molecular structure confirmation.In addition,compound 1 was screen for its activity on reversal of MDR(multidrug resistance)mediated by P-gp(P-glycoprotein).This was accomplished by using rhodamine123 exclusion on multidrug-resistant human ABCB1 gene transfected mouse T-lymphoma cell line.Outcomes revealed that MDR reversing effect was comparable to verapamil as positive control in vitro.Treatment of TPA-induced tumor promotion with 3-oxo-6β-hydroxy-β-amyrin led to reduction in the applied anti-tumor promotion experiment.The chemo-preventive effect of 3-oxo-6β-hydroxy-β-amyrin was comparable to curcumin as positive control based on the reduction of immediate early tumor antigen expression.Molecular docking by applying Autodock Vina 1 and i-GEMDOCK v 2.1 tools indicated that compound 1 gives good docking results,as determined by their fitness score and specificity.Moreover,results showed that compound 1 isolated from Pistacia integerrima precisely attached to a region where co-crystallized ligand for receptor previously existed.Our findings may explain the use of Pistacia integerrima plant extracts as an anticancer agent in folk medicine.
基金funded by Higher Education commission,Pakistan(HEC),Grant No.NRPU649.
文摘Proteintyrosine phosphatase 1B(PTP1B)inhibitionis consideredas a potentialtherapeuticfor the treatmentof cancer,type2 diabetes,andobesity.Inour presentwork,weinvestigatedtheanti-diabeticpotentialof8-hydroxydiospyrin(8-HDN)from D.lotus against the PTP1B enzyme.It showed significant inhibitory activity of PTP1B with an IC 50 value of 18.37±0.02μM.A detailed molecular docking study was carried out to analyze the binding orientation,binding energy,and mechanism of inhibition.A comparative investigation of 8-HDN in the catalytic,as well as the allosteric site of PTP1B,was performed.Binding energy data showed that compound 8-HDN is more selective for the allosteric site and hence avoids the problems associated with catalytic site inhibition.The inhibition mechanism of 8-HDN can be further investigated as an active lead compound against PTP1B by using in vitro and in vivo models.
文摘The in-soil biodegradation of Stipa tenacissima(alfa)leaves was examined.Non-linear mechanical testing was performed at various biodegradation stages.Tensile strength,loading and unloading Young’s moduli and dissipation energy decreased with the burial time,whereas plasticity increased.Field-emission scanning electron microscopy(FE-SEM)showed that the fracture cracks propagated in the longitudinal direction in the raw material,resulting in a fracture mode consisting of a mixture of middle lamella delamination and fiber pull-out.In contrast,the cracks were perpendicular to the stem axis in the biodegraded material,demonstrating an important strength loss of the load-bearing fibers.This strength loss was correlated with rapid cellulose degradation.A novel X-ray diffraction(XRD)model was implemented in order to take into account anisotropic size broadening.For the first time,XRD demonstrated the action of biodegradation on unrefined plant tissues under quasi in-situ conditions.Biodegradation induced a progressive loss of crystalline cellulose accompanied with anisotropic crystallite thinning.
基金funded by FEDER and it was carried out in collaboration with LSM and LINEO Company.
文摘In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and due to the European Council Directives on the reuse,recycling and valorization of car components and materials.The aim of our study is to investigate biochemical,physicochemical,and mechanical properties of technical flax fibers to evaluate the impact of transformation processes(scutching,hackling,and homogenization)on final properties of associated composite materials.Different chemical analysis such as Van Soest(biochemical fraction measurement),FTIR(Fourier Transform InfraRed spectroscopy),and XRD(X-ray diffraction)were carried out on different process modalities and show that there is no significant difference in terms of biochemical fraction and crystallinity index.By the same token,mechanical behavior shows that Young’s modulus is not affected by the transformation process.This result is also observed for thermal behavior.The results highlight the fact that the transformation processes of technical fibers do not really affect their physicochemical and mechanical performances.
文摘The main purpose of this study is to highlight, on the basis of statistical tests, the significant long-term changes of the Mediterranean Sea level, through the analysis of historical tide gauge records. In this framework, 14 tide gauge monthly series selected from the Permanent Service of the Mean Sea Level(PSMSL) database were used. The search for the presence or not of trends within these series, that have a temporal coverage from 59 to 142 years, was carried out using the Mann-Kendall test and the Sen’s slope estimator. The obtained results show that the Split Rt Marjana series are the only ones which does not exhibit a significant trend. The other 13 series show significant increasing trends. This result seems sufficient to suppose the presence, in the past century, of a new climatic phase on the scale of the Mediterranean basin, where the rising sea level is one of the consequences.
