The Experts below are selected from a list of 99876 Experts worldwide ranked by ideXlab platform
Abiodun O Ajibade - One of the best experts on this subject based on the ideXlab platform.
-
Mixed convection in a vertical annulus filled with Porous Material having time-periodic thermal boundary condition: steady-periodic regime
Meccanica, 2016Co-Authors: Basant K. Jha, Deborah Daramola, Abiodun O AjibadeAbstract:An analytical solution for the problem of a fully developed laminar mixed convection flow in a vertical annulus filled with Porous Material is presented, where the outer surface of the inner cylinder is heated sinusoidally and the inner surface of outer cylinder is kept at a constant temperature. The solution is based on the assumption that both the velocity and temperature profile far from the annulus entrance do not change due to infinite length of the cylinders forming the annulus. Perturbation method is employed to solve the momentum and energy equations, the graphical interpretation reveals that the effect of the dimensionless frequency Ω of the sinusoidal wall heating on the absolute value of oscillatory term of the velocity is negligible in the range 0.5 ≤ Ω ≤ 2 for air.
-
role of heat generation absorption on mixed convection flow in a vertical tube filled with Porous Material having time periodic boundary condition steady periodic regime
Transport in Porous Media, 2016Co-Authors: Basant K. Jha, Deborah Daramola, Abiodun O AjibadeAbstract:This paper discusses the hydrodynamic and thermal behaviours of a fully developed mixed convective flow of a viscous incompressible heat generating/absorbing fluid in a vertical tube filled with isotropic Porous Material having time-periodic boundary condition. The dimensionless governing equations of motion and energy subjected to the Boussinesq approximation and asymmetric heat conditions are solved analytically. Closed-form solutions are expressed in terms of modified Bessel function of first kind. The solutions obtained are graphically represented, and the effects of the dimensionless heat generation/absorption H, the dimensionless frequency \(\Omega \) and the Darcy number Da on the fluid flow are investigated. It is discovered that velocity is maximum at two different locations in the flow domain, one near the surface of the tube and another at the axis of the tube. The presence of the heat generation parameter is seen to enhance the temperature distribution and this is reflected as increase in the magnitude of the oscillation dimensionless velocity, whereas in the presence of heat absorption a reversed trend occurs.
-
mixed convection flow in a vertical tube filled with Porous Material with time periodic boundary condition steady periodic regime
Afrika Matematika, 2015Co-Authors: Basant K. Jha, Abiodun O Ajibade, Deborah DaramolaAbstract:An analytical study is reported on the hydrodynamic and thermal behaviour of a fully developed mixed convective flow in a vertical tube filled with isotropic Porous Material having time-periodic boundary condition. The analysis is performed for fully developed parallel flow and steady-periodic regime. The momentum and energy equations presented in dimensionless form along with the constraint equations for the present physical situation are solved exactly. Closed form solution are expressed in terms of modified Bessel function of first kind. The solution obtained is graphically represented and the effect of the Prandtl number \(Pr\), the dimensionless frequency \(\Omega \), and the Darcy number \(Da\) on the flow is investigated. It is discovered that velocity is maximum at two different locations in the flow domain, one near the surface of the tube and another at the axis of the tube.
Ying Xu - One of the best experts on this subject based on the ideXlab platform.
-
ultrasensitive detection of enrofloxacin in chicken muscles by surface enhanced raman spectroscopy using amino modified glycidyl methacrylate ethylene dimethacrylate gma edma powdered Porous Material
Food Analytical Methods, 2014Co-Authors: Ying Xu, Yiping Du, Qingqing Li, Xuan Wang, Han Zhang, Ting Wu, Huilian HuAbstract:Illegally use of enrofloxacin in chicken has raised serious concerns due to its negative effects on public health. In this study, surface-enhanced Raman spectroscopy (SERS) using amino-modified glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) powdered Porous Material was developed and validated to detect enrofloxacin in chicken muscles. By this method, enrofloxacin in chicken muscles was successfully detected at a concentration of 0.01 mg kg−1, which was lower than the legal maximum residue limit. And the unique “fingerprint-like” spectral patterns of enrofloxacin obtained from SERS spectra could be used for identification and characterization. Compared with high-performance liquid chromatography, the assay of six samples with SERS was rapid in less than 40 min, and the detection was highly sensitive. The results demonstrate that SERS using GMA-EDMA powdered Porous Material can be potentially employed as a screening tool for rapid detection of residual drugs in a large amount of food samples.
-
rapid atto molar level detection of surface enhanced raman spectroscopy technique based on glycidyl methacrylate ethylene dimethacrylate gma edma Porous Material
Journal of Raman Spectroscopy, 2013Co-Authors: Qingqing Li, Ying Xu, Yiping Du, Xuan Wang, Jinpei GengAbstract:A novel miniature device for rapid ultra-sensitive surface-enhanced Raman scattering (SERS) detection was developed in the present study. The device was made of a syringe, a piece of filter, and a Teflon tube. Therefore, it was with advantages of simplicity, miniaturization, and easy operability. The tube was filled in advance with the glycidyl methacrylate-ethylene dimethacrylate powder Porous Material which has been proved to increase the sensitivity of normal SERS dramatically, then the mixture solution containing the analyte, silver colloid, and NaCl solution passed through the Porous Material by the action of the syringe. SERS signals were collected from the surface of the Material. Rhodamine 6G (R6G), p-aminothiophenol (PATP), and thiabendazole (TBZ) were employed as the probe molecules in the present work. R6G at microlitre-scale can be detected at an extremely low concentration of 10–18 mol/l, and the relative standard deviation of spot to spot is 14.16% at the intensity of the band at 609 cm−1. The concentrations of PATP and TBZ that can be detected with the method are 10−11 mol/l and 1.3 × 10−6 mol/l, respectively. This method not only has achieved the ultra-sensitive detection of dye and pesticide but also realized the simple, rapid, and small sample quantity requirement detection, and it is of great potential use for lots of analytes. Copyright © 2013 John Wiley & Sons, Ltd.
-
rapid and sensitive detection of pesticides by surface enhanced raman spectroscopy technique based on glycidyl methacrylate ethylene dimethacrylate gma edma Porous Material
Chinese Chemical Letters, 2013Co-Authors: Qingqing Li, Ying Xu, Yiping Du, Xuan Wang, Jinpei GengAbstract:Abstract A novel method of fast and sensitive SERS detection using GMA–EDMA Porous Material combined with a miniature device was reported in this study. A 100 μL solution containing sample, silver colloid and NaCl was evenly mixed to ensure the sample molecules would adsorb onto silver nanoparticles. Then the mixture was added onto the Porous Material surface slowly, so that the aggregation of silver colloid would stay on the surface while the liquid components would flow away. This technology can improve the sensitivity of SERS detection. By this method, two pesticides tricyclazole and paraquat were successfully detected at concentrations of 5 × 10 −3 mg/L and 1 × 10 −3 mg/L, respectively.
Qingqing Li - One of the best experts on this subject based on the ideXlab platform.
-
ultrasensitive detection of enrofloxacin in chicken muscles by surface enhanced raman spectroscopy using amino modified glycidyl methacrylate ethylene dimethacrylate gma edma powdered Porous Material
Food Analytical Methods, 2014Co-Authors: Ying Xu, Yiping Du, Qingqing Li, Xuan Wang, Han Zhang, Ting Wu, Huilian HuAbstract:Illegally use of enrofloxacin in chicken has raised serious concerns due to its negative effects on public health. In this study, surface-enhanced Raman spectroscopy (SERS) using amino-modified glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) powdered Porous Material was developed and validated to detect enrofloxacin in chicken muscles. By this method, enrofloxacin in chicken muscles was successfully detected at a concentration of 0.01 mg kg−1, which was lower than the legal maximum residue limit. And the unique “fingerprint-like” spectral patterns of enrofloxacin obtained from SERS spectra could be used for identification and characterization. Compared with high-performance liquid chromatography, the assay of six samples with SERS was rapid in less than 40 min, and the detection was highly sensitive. The results demonstrate that SERS using GMA-EDMA powdered Porous Material can be potentially employed as a screening tool for rapid detection of residual drugs in a large amount of food samples.
-
rapid atto molar level detection of surface enhanced raman spectroscopy technique based on glycidyl methacrylate ethylene dimethacrylate gma edma Porous Material
Journal of Raman Spectroscopy, 2013Co-Authors: Qingqing Li, Ying Xu, Yiping Du, Xuan Wang, Jinpei GengAbstract:A novel miniature device for rapid ultra-sensitive surface-enhanced Raman scattering (SERS) detection was developed in the present study. The device was made of a syringe, a piece of filter, and a Teflon tube. Therefore, it was with advantages of simplicity, miniaturization, and easy operability. The tube was filled in advance with the glycidyl methacrylate-ethylene dimethacrylate powder Porous Material which has been proved to increase the sensitivity of normal SERS dramatically, then the mixture solution containing the analyte, silver colloid, and NaCl solution passed through the Porous Material by the action of the syringe. SERS signals were collected from the surface of the Material. Rhodamine 6G (R6G), p-aminothiophenol (PATP), and thiabendazole (TBZ) were employed as the probe molecules in the present work. R6G at microlitre-scale can be detected at an extremely low concentration of 10–18 mol/l, and the relative standard deviation of spot to spot is 14.16% at the intensity of the band at 609 cm−1. The concentrations of PATP and TBZ that can be detected with the method are 10−11 mol/l and 1.3 × 10−6 mol/l, respectively. This method not only has achieved the ultra-sensitive detection of dye and pesticide but also realized the simple, rapid, and small sample quantity requirement detection, and it is of great potential use for lots of analytes. Copyright © 2013 John Wiley & Sons, Ltd.
-
rapid and sensitive detection of pesticides by surface enhanced raman spectroscopy technique based on glycidyl methacrylate ethylene dimethacrylate gma edma Porous Material
Chinese Chemical Letters, 2013Co-Authors: Qingqing Li, Ying Xu, Yiping Du, Xuan Wang, Jinpei GengAbstract:Abstract A novel method of fast and sensitive SERS detection using GMA–EDMA Porous Material combined with a miniature device was reported in this study. A 100 μL solution containing sample, silver colloid and NaCl was evenly mixed to ensure the sample molecules would adsorb onto silver nanoparticles. Then the mixture was added onto the Porous Material surface slowly, so that the aggregation of silver colloid would stay on the surface while the liquid components would flow away. This technology can improve the sensitivity of SERS detection. By this method, two pesticides tricyclazole and paraquat were successfully detected at concentrations of 5 × 10 −3 mg/L and 1 × 10 −3 mg/L, respectively.
Basant K. Jha - One of the best experts on this subject based on the ideXlab platform.
-
Mixed convection in a vertical annulus filled with Porous Material having time-periodic thermal boundary condition: steady-periodic regime
Meccanica, 2016Co-Authors: Basant K. Jha, Deborah Daramola, Abiodun O AjibadeAbstract:An analytical solution for the problem of a fully developed laminar mixed convection flow in a vertical annulus filled with Porous Material is presented, where the outer surface of the inner cylinder is heated sinusoidally and the inner surface of outer cylinder is kept at a constant temperature. The solution is based on the assumption that both the velocity and temperature profile far from the annulus entrance do not change due to infinite length of the cylinders forming the annulus. Perturbation method is employed to solve the momentum and energy equations, the graphical interpretation reveals that the effect of the dimensionless frequency Ω of the sinusoidal wall heating on the absolute value of oscillatory term of the velocity is negligible in the range 0.5 ≤ Ω ≤ 2 for air.
-
role of heat generation absorption on mixed convection flow in a vertical tube filled with Porous Material having time periodic boundary condition steady periodic regime
Transport in Porous Media, 2016Co-Authors: Basant K. Jha, Deborah Daramola, Abiodun O AjibadeAbstract:This paper discusses the hydrodynamic and thermal behaviours of a fully developed mixed convective flow of a viscous incompressible heat generating/absorbing fluid in a vertical tube filled with isotropic Porous Material having time-periodic boundary condition. The dimensionless governing equations of motion and energy subjected to the Boussinesq approximation and asymmetric heat conditions are solved analytically. Closed-form solutions are expressed in terms of modified Bessel function of first kind. The solutions obtained are graphically represented, and the effects of the dimensionless heat generation/absorption H, the dimensionless frequency \(\Omega \) and the Darcy number Da on the fluid flow are investigated. It is discovered that velocity is maximum at two different locations in the flow domain, one near the surface of the tube and another at the axis of the tube. The presence of the heat generation parameter is seen to enhance the temperature distribution and this is reflected as increase in the magnitude of the oscillation dimensionless velocity, whereas in the presence of heat absorption a reversed trend occurs.
-
mixed convection flow in a vertical tube filled with Porous Material with time periodic boundary condition steady periodic regime
Afrika Matematika, 2015Co-Authors: Basant K. Jha, Abiodun O Ajibade, Deborah DaramolaAbstract:An analytical study is reported on the hydrodynamic and thermal behaviour of a fully developed mixed convective flow in a vertical tube filled with isotropic Porous Material having time-periodic boundary condition. The analysis is performed for fully developed parallel flow and steady-periodic regime. The momentum and energy equations presented in dimensionless form along with the constraint equations for the present physical situation are solved exactly. Closed form solution are expressed in terms of modified Bessel function of first kind. The solution obtained is graphically represented and the effect of the Prandtl number \(Pr\), the dimensionless frequency \(\Omega \), and the Darcy number \(Da\) on the flow is investigated. It is discovered that velocity is maximum at two different locations in the flow domain, one near the surface of the tube and another at the axis of the tube.
Yiping Du - One of the best experts on this subject based on the ideXlab platform.
-
ultrasensitive detection of enrofloxacin in chicken muscles by surface enhanced raman spectroscopy using amino modified glycidyl methacrylate ethylene dimethacrylate gma edma powdered Porous Material
Food Analytical Methods, 2014Co-Authors: Ying Xu, Yiping Du, Qingqing Li, Xuan Wang, Han Zhang, Ting Wu, Huilian HuAbstract:Illegally use of enrofloxacin in chicken has raised serious concerns due to its negative effects on public health. In this study, surface-enhanced Raman spectroscopy (SERS) using amino-modified glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) powdered Porous Material was developed and validated to detect enrofloxacin in chicken muscles. By this method, enrofloxacin in chicken muscles was successfully detected at a concentration of 0.01 mg kg−1, which was lower than the legal maximum residue limit. And the unique “fingerprint-like” spectral patterns of enrofloxacin obtained from SERS spectra could be used for identification and characterization. Compared with high-performance liquid chromatography, the assay of six samples with SERS was rapid in less than 40 min, and the detection was highly sensitive. The results demonstrate that SERS using GMA-EDMA powdered Porous Material can be potentially employed as a screening tool for rapid detection of residual drugs in a large amount of food samples.
-
rapid atto molar level detection of surface enhanced raman spectroscopy technique based on glycidyl methacrylate ethylene dimethacrylate gma edma Porous Material
Journal of Raman Spectroscopy, 2013Co-Authors: Qingqing Li, Ying Xu, Yiping Du, Xuan Wang, Jinpei GengAbstract:A novel miniature device for rapid ultra-sensitive surface-enhanced Raman scattering (SERS) detection was developed in the present study. The device was made of a syringe, a piece of filter, and a Teflon tube. Therefore, it was with advantages of simplicity, miniaturization, and easy operability. The tube was filled in advance with the glycidyl methacrylate-ethylene dimethacrylate powder Porous Material which has been proved to increase the sensitivity of normal SERS dramatically, then the mixture solution containing the analyte, silver colloid, and NaCl solution passed through the Porous Material by the action of the syringe. SERS signals were collected from the surface of the Material. Rhodamine 6G (R6G), p-aminothiophenol (PATP), and thiabendazole (TBZ) were employed as the probe molecules in the present work. R6G at microlitre-scale can be detected at an extremely low concentration of 10–18 mol/l, and the relative standard deviation of spot to spot is 14.16% at the intensity of the band at 609 cm−1. The concentrations of PATP and TBZ that can be detected with the method are 10−11 mol/l and 1.3 × 10−6 mol/l, respectively. This method not only has achieved the ultra-sensitive detection of dye and pesticide but also realized the simple, rapid, and small sample quantity requirement detection, and it is of great potential use for lots of analytes. Copyright © 2013 John Wiley & Sons, Ltd.
-
rapid and sensitive detection of pesticides by surface enhanced raman spectroscopy technique based on glycidyl methacrylate ethylene dimethacrylate gma edma Porous Material
Chinese Chemical Letters, 2013Co-Authors: Qingqing Li, Ying Xu, Yiping Du, Xuan Wang, Jinpei GengAbstract:Abstract A novel method of fast and sensitive SERS detection using GMA–EDMA Porous Material combined with a miniature device was reported in this study. A 100 μL solution containing sample, silver colloid and NaCl was evenly mixed to ensure the sample molecules would adsorb onto silver nanoparticles. Then the mixture was added onto the Porous Material surface slowly, so that the aggregation of silver colloid would stay on the surface while the liquid components would flow away. This technology can improve the sensitivity of SERS detection. By this method, two pesticides tricyclazole and paraquat were successfully detected at concentrations of 5 × 10 −3 mg/L and 1 × 10 −3 mg/L, respectively.
