Corrugated surface microparticles with chitosan and levofloxacin for improved aerodynamic performance

Corrugated surface microparticles comprising levofloxacin(LEV),chitosan and organic acid were prepared using the 3-combo spray drying method.The amount and the boiling point of the organic acid affected the degree of roughness.In this study,we tried to improve the aerodynamic performance and increase aerosolization by corrugated surface microparticle for lung drug delivery efficiency as dry powder inhaler.HMP175 L20 prepared with 175 mmol propionic acid solution was corrugated more than HMF175 L20 prepared with 175 mmol formic acid solution.The ACI and PIV results showed a significant increase in aerodynamic performance of corrugated microparticles.The FPF value of HMP175 L20 was 41.3%±3.9%compared with 25.6%±7.7%of HMF175 L20.Corrugated microparticles also showed better aerosolization,decreased x-axial velocity,and variable angle.Rapid dissolution of drug formulationswas observed in vivo.Lowdoses administered to the lungs achieved higher LEV concentrations in the lung fluid than high doses administered orally.Surface modification in the polymer-based formulation was achieved by controlling the evaporation rate and improving the inhalation efficiency of DPIs.

Numerical investigation on adiabatic film cooling effectiveness and heat transfer coefficient for effusion cooling over a transverse corrugated surface

Three-dimensional numerical computations are conducted to investigate the effects of the blowing ratio and corrugation geometry on the adiabatic film cooling effectiveness as well as the heat transfer coefficient over a transverse corrugated surface.It is noticeable that the adiabatic wall temperature on the wavy valley of the transverse corrugated surface is relatively lower than that on the wavy peak.Surface corrugation has a relatively obvious influence on the laterallyaveraged adiabatic film cooling effectiveness in the region where the effusion film layer is developed,but has little influence in the front region.Compared to a flat surface,the transverse corrugated surface produces a smaller adiabatic film cooling effectiveness and a higher heat transfer coefficient ratio.The effusion cooling difference between the flat and corrugated surfaces behaves more obviously under a small aspect ratio of the wavy corrugation.

ANALYTICAL AND NUMERICAL SOLUTIONS FOR THE FLOW IN MICROTUBE WITH THREE-DIMENSIONAL CORRUGATED SURFACE,PART 1:STEADY FLOW

The influences of three-dimensional corrugated wall on the fully-developed steady no-slip flows in microtube are studied by analytical and numerical methods in this article. Detailed analytical solutions for the space-averaged equations and the numerical method for the solutions of the disturbance equations are given. An iterative arithm of coupled equations with respect to space-averaged velocities and disturbance velocities is suggested. The study shows that a three-dimensional subsidiary stress layer exists in the near-wall region. The relative roughness, wavenumber and Reynolds number are three important parameters influencing the subsidiary stresses and the space-averaged pressure drop. The space-averaged pressure drop subject to an invariable flow rate mainly depends on the position of datum surface. When the datum surface is taken at the balance position of wall function, the value of pressure drop is determined by the dynamic characteristics of the flow.

Surface Corrugation in Rotational and Diffractive Scattering of O_2 from LiF(001)

A quantum dynamic calculation on a five-dimensional O2/LiF （001） model system is performed using themulti-configuration time-dependent Hartree method.The obtained results show that the mechanism of rotational anddiffractive excitation in details: Comparison with the rotational excited state, the initially non-rotational state is seento favor the inelastic scattering in the rotational excitation process.The surface corrugation can damp the quantuminterferences and produce a greater amount of rotational inelastic scattering at the expense of the elastic process inthe rotational excitation process.The diffraction process and the average energy transferred into the rotational anddiffractive mode are also discussed.

Heat transfer and flow characteristics in a channel with one corrugated wall

The present study numerically investigates the characteristics of three-dimensional turbulent flow and heat transfer in the channel with one corrugated wall heated with constant temperature by means of large eddy simulation.The corrugated wall is sinusoidal in the streamwise and spanwise directions.The Reynolds number in terms of bulk velocity and channel half-height is fixed at 2800 and the wave amplitude to wavelength ratio is varied in the rangeα/λ=0.01,0.02,0.04 in the streamwise direction andα/λ=0.01,0.02,0.04 in the spanwise direction.The results show that flow separation bubbles appear and near-wall streamwise vortices are generated with larger population in the upslope region of the bottom wall as wave amplitude increases.Compared with flat wall,the corrugated geometry increases the pressure coefficient and decreases the friction coefficient on the corrugated wall,and consequently increases the total drag coefficient owing to the increase of pressure coefficient,as expected,the heat transfer is higher.The waves in the spanwise direction converge the vortices into the trough along the streamwise direction and push them away from the bottom wall.Finally,thermal performance factor is defined and the effects of wave amplitude on the thermal performance are scrutinized.