The composite structure with the dielectric elastomer and soft materials is the main form of theactuators in soft robots. However, the theoretical model is hard to obtain due to the nonlinear large deformationof mater...The composite structure with the dielectric elastomer and soft materials is the main form of theactuators in soft robots. However, the theoretical model is hard to obtain due to the nonlinear large deformationof materials. In this paper, a new composite element model is established based on the absolute nodal coordinateformulation. The consistent deformation conditions at the contact interface between two thin plates are deduced.The hyperelastic constitutive model and the dielectric elastomer constitutive model are introduced for the twothin plates. Then the dynamic model is established to study the dynamic behaviors of the composite flexiblestructure with various parameters. The results show that the nonlinear deformation appears obviously whenthe flexible composite plate structure is driven by various voltages, and the warping deformation becomes moreobvious with the increase of the voltage. The width and thickness of the driven thin plate influence the stabilityof the whole structure. With the decrease of the width or thickness, the deformation of the structure is moreconsistent with obvious periodicity, and the control performance is improved. Finally, the structural parametersof the composite structures are optimized to improve the control performance based on the dynamic performance.Additionally, smaller width and thickness parameters are preferred to obtain better performance in the design offlexible actuator of soft robot.展开更多
Introduction: In this study, physical and chemical characteristics of Lamivudine, Tenofovir Disoproxil Fumarate (TDF) and potential excipients were systematically followed and documented [1]. Objective: The objective ...Introduction: In this study, physical and chemical characteristics of Lamivudine, Tenofovir Disoproxil Fumarate (TDF) and potential excipients were systematically followed and documented [1]. Objective: The objective of this scientific work was to carry out pre-formulation studies including compatibility studies on Lamivudine and Tenofovir Disoproxil Fumarate with their potential excipients prior a direct compression process [2]. Methodology: The interaction was studied in three set of environments namely uncontrolled room conditions for Zone VI b (30°C ± 2°C), oven conditions in which the oven was set at 50°C and accelerated climatic conditions in which a climatic chamber was set at 40°C ± 2°C/75% ± 5% Relative Humidity (RH %). Sample preparation was done by mixing the amount of formulation excipients to active substances at a ratio of 1:10, whereas active substance to another active substance at a ratio of 1:1, active substance to coating materials at 1:4, coating materials to the whole set of excipients 1:4. The whole set of samples was geometrically mixed and triturated by mortar and pestle to very fine uniform powder to ensure homogeneity of the mixture. HPLC analytical method was used for simultaneous quantitative determination of lamivudine and tenofovir disoproxil fumarate. Transmittance of the mixture was determined by Near Infra-Red (NIR) technique. Results: The amount of Lamivudine as on day 0 was comparable to day 90 for in all tested conditions (Room, Oven and Climatic Chamber), whereas for Tenofovir Disoproxil Fumarate only the amount of the drug at Room (30°C ± 2°C) was comparable to results on day 90. A significant drop of amount of Tenofovir Disoproxil Fumarate (TDF) exposed to moisture (Climatic chamber at 40°C ± 2°C/75% ± 5% Relative Humidity (RH %)) and temperature of 50°C was observed. Colour change was observed for samples subjected to moisture (Climatic chamber at 40°C ± 2°C/75% ± 5% Relative Humidity (RH %)) and as well picked up in the NIR region 400 to 1500 cm<sup>-1<展开更多
基金the National Natural Science Foundation of China(No.51775345)。
文摘The composite structure with the dielectric elastomer and soft materials is the main form of theactuators in soft robots. However, the theoretical model is hard to obtain due to the nonlinear large deformationof materials. In this paper, a new composite element model is established based on the absolute nodal coordinateformulation. The consistent deformation conditions at the contact interface between two thin plates are deduced.The hyperelastic constitutive model and the dielectric elastomer constitutive model are introduced for the twothin plates. Then the dynamic model is established to study the dynamic behaviors of the composite flexiblestructure with various parameters. The results show that the nonlinear deformation appears obviously whenthe flexible composite plate structure is driven by various voltages, and the warping deformation becomes moreobvious with the increase of the voltage. The width and thickness of the driven thin plate influence the stabilityof the whole structure. With the decrease of the width or thickness, the deformation of the structure is moreconsistent with obvious periodicity, and the control performance is improved. Finally, the structural parametersof the composite structures are optimized to improve the control performance based on the dynamic performance.Additionally, smaller width and thickness parameters are preferred to obtain better performance in the design offlexible actuator of soft robot.
文摘Introduction: In this study, physical and chemical characteristics of Lamivudine, Tenofovir Disoproxil Fumarate (TDF) and potential excipients were systematically followed and documented [1]. Objective: The objective of this scientific work was to carry out pre-formulation studies including compatibility studies on Lamivudine and Tenofovir Disoproxil Fumarate with their potential excipients prior a direct compression process [2]. Methodology: The interaction was studied in three set of environments namely uncontrolled room conditions for Zone VI b (30°C ± 2°C), oven conditions in which the oven was set at 50°C and accelerated climatic conditions in which a climatic chamber was set at 40°C ± 2°C/75% ± 5% Relative Humidity (RH %). Sample preparation was done by mixing the amount of formulation excipients to active substances at a ratio of 1:10, whereas active substance to another active substance at a ratio of 1:1, active substance to coating materials at 1:4, coating materials to the whole set of excipients 1:4. The whole set of samples was geometrically mixed and triturated by mortar and pestle to very fine uniform powder to ensure homogeneity of the mixture. HPLC analytical method was used for simultaneous quantitative determination of lamivudine and tenofovir disoproxil fumarate. Transmittance of the mixture was determined by Near Infra-Red (NIR) technique. Results: The amount of Lamivudine as on day 0 was comparable to day 90 for in all tested conditions (Room, Oven and Climatic Chamber), whereas for Tenofovir Disoproxil Fumarate only the amount of the drug at Room (30°C ± 2°C) was comparable to results on day 90. A significant drop of amount of Tenofovir Disoproxil Fumarate (TDF) exposed to moisture (Climatic chamber at 40°C ± 2°C/75% ± 5% Relative Humidity (RH %)) and temperature of 50°C was observed. Colour change was observed for samples subjected to moisture (Climatic chamber at 40°C ± 2°C/75% ± 5% Relative Humidity (RH %)) and as well picked up in the NIR region 400 to 1500 cm<sup>-1<
