Analysis of Large Non-linear Elastic Deformation of Fabrics

The effect of material non-linearity on large lateral deformations of fabrics structures was studied. Fixing the boundaries, the deformation under uniform internal pressure was analyzed by nonlinear FEM (Finite Element Method). Because non-linear elasticity was found in the tensile testing of fabrics, the non-linear tensile characteristic was also considered in the FEM. Some experiments were conducted under various fixed conditions and the displacement was measured by a laser displacement sensor. The calculated results considering the non linear tensile elasticity of materials were found to agree with the experimental ones. Thus the validity of the proposed calculation method was proven.     

Online time-differential perturbed angular correlation study with an O beam - Residence sites of oxygen atoms in highly oriented pyrolytic graphite

The online time-differential perturbed angular correlation (TDPAC) method was applied to a study of the physical states of a probe ¹⁹F, the β⁻ decay product of ¹⁹O (t_1/2 = 26.9 s), implanted in highly oriented pyrolytic graphite. The observed magnitude of the electric field gradient at the probe nucleus, ∣V_zz∣ = 2.91(17) × 10²² V m⁻², suggests that the incident ¹⁹O atoms are stabilized at an interlayer position with point group C_3v. Exhibiting observed TDPAC spectra having a clear sample-to-detector configuration dependence, we demonstrate the applicability of the present online method with a short-lived radioactive ¹⁹O beam.     

Management of excess energy in a photovoltaic/grid system by production of clean hydrogen

In this article, the authors design a new clean storage device for a photovoltaic system (PV) reinforced by the electrical grid. The photovoltaic system supplies power to a DC load. When the power of the photovoltaic source is insufficient, the electrical grid compensates the energy deficit. On the other hand, if the load is satisfied and the PV source is still able of supplying energy, the energy excess is diverted to an own storage unit materialized by an electrolysis which produces gaseous hydrogen by the process of electrolysis of water. The authors show that the quantity of hydrogen produced is proportional to the photovoltaic energy excess and also to the flow of water injected into the electrolysis. In this case, it is a question of designing an electrolysis with specific characteristics, which takes into account the quantity of energy excess and the flow of water injected into it. The authors abandon the idea of controlling the water flow by means of a pumping-electrovalve system, and initiate the idea of replacing the function of the pump by the action of gravity. The work focuses on the development of an electrolysis optimization approach using the water flow control in its alliance with the PV power excess which is also maximized. For an optimized use of the global system (load and electrolysis), the authors present an architecture based on energy-converting structures (DC/DC and AC/DC). In addition, to increase the reliability and safety of the system, the authors finish by developing a power management strategy (PMS) in the designed system. This power management strategy organizes the energy flow and selects the appropriate path of this flow between the two energy sources (PV and electrical grid) and the two possible energy receivers (load and electrolysis). A complete modeling of the system is developed in the Matlab/Simulink environment. The simulation results show that the hybrid system (PV and electrical grid) is able to permanently supplying the load and potentially storing the excess of the PV energy in the form of hydrogen gas.     

Application of full-factorial design for optimization of the moisture determination in wheat flour using infrared scales

We studied the parameters that may affect the analysis of the moisture content in wheat flour using infrared scales. The parameters were studied by one-factor at a time methodology and then, by full-factorial design (2³). The best condition using infrared scales occurred at 120 °C, with a sample weight of 1.5 g and an exposure time to infrared radiation of 6 min. We observed the interaction effect between the three factors studied. The analysis time was 60 times lower than classical method. The optimized method for determination of the moisture content in wheat flour using infrared scales was validated to range between 9 and 17 %.     

Simulation of kinetic analysis on terpolymerization of styrene/butyl methacrylate/methacrylic acid system

The simultaneous differential equations which connected the copolymerization kinetics of the component reaction in the multi-copolymerization system with the changing rate of the concentration of each monomer and radical, the concentration and the molecular weight of the polymer obtained are analysed in a number of ways. The distribution of the components and the degree of polymerization are also simulated. The styrene/butyl methacrylate/methacrylic acid terpolymerization system, using carbon tetrachloride as solvent and benzoyl peroxide as initiator, was chosen. The simulation model which satisfied the experimental values of the concentration of the multiple components in the system, the composition and molecular weight distribution and the number of chlorine atoms introduced into the copolymer ends is established. When the time interval changed, the effects on the distribution of the composition in copolymers and the distribution of the degree of polymerization were also calculated.