Water diffusion of two species of coconut shells (CS) nucifera from Cameroon, in the case of drying, was experimentally studied. The experiment was done with the aid of an oven, by the method of gravimetric batch cont...Water diffusion of two species of coconut shells (CS) nucifera from Cameroon, in the case of drying, was experimentally studied. The experiment was done with the aid of an oven, by the method of gravimetric batch control of the mass of the test samples with the temperatures varied from 70° to 180° Celsius. The shells of mature coconuts from two species were conserved in the laboratory at a temperature ranging between 20° and 23° Celsius for two months before being mechanically cleaned. This study allows not only the determination of the water content of the shells, but also the identification of the drying model. It is thus from the ten model tests, and the statistical analysis shows that the Midilli model best predicted this drying phenomenon. The coefficient of effective diffusion was determined at different temperatures which permitted the evaluation of the activation energy per the Arrhenius equation.展开更多
Biomethane potential production from cashew nut hulls, an agricultural waste, was carried out using old and fresh hulls as substrates. Samples were taken from old hulls (around 8 years old) and fresh hulls produced in...Biomethane potential production from cashew nut hulls, an agricultural waste, was carried out using old and fresh hulls as substrates. Samples were taken from old hulls (around 8 years old) and fresh hulls produced in cashew scale transformation units at Bobo Dioulasso/Burkina Faso. Physicochemical parameters showed that cashew hulls can be </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">good candidate for anaerobic digestion. But high acidity, total phenols and lignin tenor could be a constraint for anaerobic bacteria. Theoretical biochemical methane potential showed high value of 666</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">937 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 526</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">206 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> for crushed fresh and powdered old hulls, respectively. Experimental biochemical methane potential showed significantly low potential of</span> <span style="font-family:Verdana;">1.982 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 46.840 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;"></span><span style=展开更多
An empirical formula is proposed to calculate the total binding energy of the outer electrons of atoms and their ions to a high accuracy. It is the authors’ opinion that the validity of the proposed formula testifies...An empirical formula is proposed to calculate the total binding energy of the outer electrons of atoms and their ions to a high accuracy. It is the authors’ opinion that the validity of the proposed formula testifies that electronic shells have some “spatial structures”, and the nature of which depends neither on the nucleus charge, nor on the number of the electrons in a shell.展开更多
The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structure...The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structured Si/C composite (denoted as TSC-PDA-B) has been intelligently designed by rational engineering and precise control. In the novel structure, the multiple Si nanoparticles with small size are successfully encapsulated into the porous carbon shells with double layers benefiting from the strong etching effect of HF. The TSC-PDA-B product prepared is evaluated as anode materials for lithium-ion batteries (LIBs). The TSC-PDA-B product exhibits an excellent lithium storage performance with a high initial capacity of 2108 mAh g^-1 at a current density of 100 mA g^-1 and superior cycling performance of 1113 mAh g^-1 over 200 cycles. The enhancement of lithium storage performance may be attributed to the construction of hybrid structure including small Si nanoparticles, high surface area, and double carbon shells, which can not only increase electrical conductiv让y and intimate electrical contact with Si nanoparticles, but also provide built-in buffer voids for Si nanoparticles to expand freely without damaging the carbon layer. The present findings can provide some scientific insights into the design and the application of advanced Si-based anode materials in energy storage fields.展开更多
The study is focused on the phenomenon of diffusion of water through the shells of two coconut species (coconut nucifera) of Cameroun. The kinetics absorption of water was studied experimentally by the gravimetric met...The study is focused on the phenomenon of diffusion of water through the shells of two coconut species (coconut nucifera) of Cameroun. The kinetics absorption of water was studied experimentally by the gravimetric method with discontinuous control of the mass of the samples at the temperature of 23℃. The mature coconut shells were cleaned mechanically, cut in a spherical shape and placed in a drying oven with 105℃ for 4 hours before being plunged in distilled water at 23℃. This study made it possible not only to determine the rate of water absorbed, but also to model the water kinetic absorption of the shells. Of the two models tested (Peleg and Page), the Page model predicted very well the experimental data. The Fick law made it possible to evaluate the effective diffusivity coefficients at the initial and final phases of absorption. The effective diffusivity coefficient was given from the Arrhenius equation.展开更多
This short letter reports on an unsuspected and quite surprising connection between capillary forces and dark energy. We start with a very brief introduction of the role played by relativistic hydrodynamics in cosmic ...This short letter reports on an unsuspected and quite surprising connection between capillary forces and dark energy. We start with a very brief introduction of the role played by relativistic hydrodynamics in cosmic dark energy research, and then proceed from there to outline the proposed analogy between dark energy and non-relativistic effects of capillary surface energy.展开更多
An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a...An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a hyperbolic fractal Rindler space-time leading to the same robust results regarding real energy and dark energy being 4.5% and 95.5% respectively in full agreement with all recent cosmological measurements.展开更多
文摘Water diffusion of two species of coconut shells (CS) nucifera from Cameroon, in the case of drying, was experimentally studied. The experiment was done with the aid of an oven, by the method of gravimetric batch control of the mass of the test samples with the temperatures varied from 70° to 180° Celsius. The shells of mature coconuts from two species were conserved in the laboratory at a temperature ranging between 20° and 23° Celsius for two months before being mechanically cleaned. This study allows not only the determination of the water content of the shells, but also the identification of the drying model. It is thus from the ten model tests, and the statistical analysis shows that the Midilli model best predicted this drying phenomenon. The coefficient of effective diffusion was determined at different temperatures which permitted the evaluation of the activation energy per the Arrhenius equation.
文摘Biomethane potential production from cashew nut hulls, an agricultural waste, was carried out using old and fresh hulls as substrates. Samples were taken from old hulls (around 8 years old) and fresh hulls produced in cashew scale transformation units at Bobo Dioulasso/Burkina Faso. Physicochemical parameters showed that cashew hulls can be </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">good candidate for anaerobic digestion. But high acidity, total phenols and lignin tenor could be a constraint for anaerobic bacteria. Theoretical biochemical methane potential showed high value of 666</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">937 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 526</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">206 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> for crushed fresh and powdered old hulls, respectively. Experimental biochemical methane potential showed significantly low potential of</span> <span style="font-family:Verdana;">1.982 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 46.840 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;"></span><span style=
文摘An empirical formula is proposed to calculate the total binding energy of the outer electrons of atoms and their ions to a high accuracy. It is the authors’ opinion that the validity of the proposed formula testifies that electronic shells have some “spatial structures”, and the nature of which depends neither on the nucleus charge, nor on the number of the electrons in a shell.
基金financially supported by the National Natural Science Foundation of China(21471096)Shanghai Pujiang Program(17PJD015)
文摘The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structured Si/C composite (denoted as TSC-PDA-B) has been intelligently designed by rational engineering and precise control. In the novel structure, the multiple Si nanoparticles with small size are successfully encapsulated into the porous carbon shells with double layers benefiting from the strong etching effect of HF. The TSC-PDA-B product prepared is evaluated as anode materials for lithium-ion batteries (LIBs). The TSC-PDA-B product exhibits an excellent lithium storage performance with a high initial capacity of 2108 mAh g^-1 at a current density of 100 mA g^-1 and superior cycling performance of 1113 mAh g^-1 over 200 cycles. The enhancement of lithium storage performance may be attributed to the construction of hybrid structure including small Si nanoparticles, high surface area, and double carbon shells, which can not only increase electrical conductiv让y and intimate electrical contact with Si nanoparticles, but also provide built-in buffer voids for Si nanoparticles to expand freely without damaging the carbon layer. The present findings can provide some scientific insights into the design and the application of advanced Si-based anode materials in energy storage fields.
文摘The study is focused on the phenomenon of diffusion of water through the shells of two coconut species (coconut nucifera) of Cameroun. The kinetics absorption of water was studied experimentally by the gravimetric method with discontinuous control of the mass of the samples at the temperature of 23℃. The mature coconut shells were cleaned mechanically, cut in a spherical shape and placed in a drying oven with 105℃ for 4 hours before being plunged in distilled water at 23℃. This study made it possible not only to determine the rate of water absorbed, but also to model the water kinetic absorption of the shells. Of the two models tested (Peleg and Page), the Page model predicted very well the experimental data. The Fick law made it possible to evaluate the effective diffusivity coefficients at the initial and final phases of absorption. The effective diffusivity coefficient was given from the Arrhenius equation.
文摘This short letter reports on an unsuspected and quite surprising connection between capillary forces and dark energy. We start with a very brief introduction of the role played by relativistic hydrodynamics in cosmic dark energy research, and then proceed from there to outline the proposed analogy between dark energy and non-relativistic effects of capillary surface energy.
文摘An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a hyperbolic fractal Rindler space-time leading to the same robust results regarding real energy and dark energy being 4.5% and 95.5% respectively in full agreement with all recent cosmological measurements.
