Biospeckle Activity of Highbush Blueberry Fruits Infested by Spotted Wing Drosophila (Drosophila suzukii Matsumura)

In this study, the potential of the biospeckle phenomenon for detecting fruit infestation by Drosophila suzukii was examined. We tested both graphical and analytical approaches to evaluate biospeckle activity of healthy and infested fruits. As a result of testing the qualitative approach, a generalized difference method proved to be better at identifying infested areas than Fujii’s method. Biospeckle activity of healthy fruits was low and increased with infestation development. It was found that the biospeckle activity index calculated from spatial-temporal speckle correlation of THSP was the best discriminant of healthy fruits and fruits in two different stages of infestation development irrespective of window size and pixel selection strategy adopted to create the THSP. Other numerical indicators of biospeckle activity (inertia moment, absolute value of differences, average differences) distinguished only fruits in later stage of infestation. Regular values of differences turned out to be of no use in detecting infested fruits. We found that to provide a good representation of activity it was necessary to use a strategy aimed at random selection of pixels gathered around the global maximum of biospeckle activity localized on the graphical outcome. The potential of biospeckle analysis for identification of highbush blueberry fruits infested by D. suzukii was confirmed.

Band gap characteristics of friction stir additive manufactured phononic crystals

Additive Manufacturing (AM) is widely used to fabricate phononic crystals (PnCs) in recent years. Friction Stir Additive Manufacturing (FSAM) is a new-type solid state fabrication technology which is fusion free with low distortions. FSAM was selected to fabricate the designed PnCs. The manufactured specimen was distorted due to the temperature rise in the manufacturing process and the band gaps (BGs) were changed with the distortions. Results indicate that the band gap of the PnCs moves to be in higher frequency domain due to the residual distortions of the manufactured PnCs. The residual distortion of FSAM PnCs is 2.77 times smaller in comparison with the Tungsten Inert Gas (TIG) welding. So, the differences of the band gap between the designed PnCs and the FSAM specimen are only in the range of 0.15%- 0.55% due to the lower temperature rise in FSAM. The further analysis shows that the change of the BGs is caused by the growth of the inertia moment for the FSAM PnCs. With the increase of the rotating speed in FSAM, the residual distortion of the FSAM PnCs is increased due to the increase of the welding temperature. This can lead to the increase of the inertia moment, which is the key reason for the increase of the BG characteristics of the FSAM PnCs.

Effective shaping of a bisymmetrical cross section of beams under shear stresses constraints

The subject of the studies is effective shaping of an analytically defined, bisymmetrical cross section of beams. The objective function concerns the maximum of the inertia moment and minimum of the area of the cross section. The constraint condition takes into account the maximum shear stresses. The effective shapes of the exemplary beams are derived. Results of the analytical study are presented in Tables and Figures.

Calculation of Nuclear Properties for 56–62Fe Isotopes in the Model Space (HO) Using NuShellX@MSU Code

The nuclear shell model has been applied to calculate the yrast energy levels, quadrupole transition probability (BE2), deformation parameter B2, rotational energy (hw), and inertia moment (20/h2) for the ground state band. The NuShellX@MSU code has been used to determine the nuclear properties of 56−62Fe isotopes, by using the harmonic oscillator (HO) model space for P (1f7/2), N (2p3/2), N (1f5/2), and N (2p1/2) orbits and (HO) interaction. The results are in good agreement with the available experimental data on the above nuclear properties and all nuclei under study. In addition, the back bending phenomenon has been explained by the calculations, and it has been very clear in 58,60,62Fe nuclei. It has also been confirmed and determined the most spins and parities of energy levels. In these calculations, new values have been theoretically determined for the most nuclear properties which were previously experimentally unknown.

Investigating the effect of the impeller blade gradient angle on the compressor reliability

Studies show that operating stress and natural frequency of the turbocharger impeller are two key parameters that affect the service life of the turbocharger. In this regard, NREC and ANSYS software are utilized in the present study to design impellers and calculate the impeller stress, natural frequency, and the inertia moment of the impeller for each baseline impeller and their modifications. Furthermore, modal tests are carried out to verify the simulation results. Finally, the compressor characteristic maps before and after the blade gradient angle optimization are compared. Obtained results show that compared with the cantilever length, the blade thickness has a remarkable influence on the blade gradient angle. Moreover, it is found that the correlation between the blade gradient angle and the first-order frequency multiplication ratio is linear. As the blade gradient angle increases, the maximum stress at the blade root of the compressor initially decreases and then increases. The value of the blade gradient angle varies within the range of 2.288°–3.955°. Moreover, the closer the gradient angle to 3.26°, the smaller the maximum equivalent stress of the impeller, and the higher the impeller strength. The greater the thickness of the blade, the longer the cantilever length of the impeller, and the greater the inertia moment. Optimizing the blade gradient angle can improve the efficiency of the compressor without changing the pressure ratio and flow rate. It should be indicated that error between the results from the simulation and the experiment is within the range 1.736%–1.254%. Therefore, the calculation results are reliable. It is concluded that the regular pattern of the blade gradient angle affects the compressor impeller stress and its natural frequency. The present article is expected to provide a helpful theoretical basis for designing an optimized compressor impeller.

Development Of A Quick Design Method For Composite Concrete Slab-Over Steel I-Girder Bridges For Project Bidding

In bridge analysis, designers calculate maximum bending moment, MT, and shear force, VT, of a bridge girder under truck loading, then use available truck fraction, FT to generate the longitudinal live load effects. This Thesis presents structural analysis of different girder configurations subjected to CL-W truck loading. Girder geometries include single-, two-, three- and four-span girders. The maximum shear, deflection and moments were plotted and then used to develop equations to represent their values. Furthermore, a software was developed to perform composite steel I-girder design. The software optimizes the I-girder size based on CHBDC design procedure. Using the developed software, a parametric study was conducted to determine the required composite moment of inertia, moment of inertia of the bare steel section and steel web area to satisfy all design requirements. Empirical equations for these three properties were developed to assist bridge designers in estimating steel I-section sizes for contract bidding.

Development Of A Quick Design Method For Composite Concrete Slab-Over Steel I-Girder Bridges For Project Bidding

In bridge analysis, designers calculate maximum bending moment, MT, and shear force, VT, of a bridge girder under truck loading, then use available truck fraction, FT to generate the longitudinal live load effects. This Thesis presents structural analysis of different girder configurations subjected to CL-W truck loading. Girder geometries include single-, two-, three- and four-span girders. The maximum shear, deflection and moments were plotted and then used to develop equations to represent their values. Furthermore, a software was developed to perform composite steel I-girder design. The software optimizes the I-girder size based on CHBDC design procedure. Using the developed software, a parametric study was conducted to determine the required composite moment of inertia, moment of inertia of the bare steel section and steel web area to satisfy all design requirements. Empirical equations for these three properties were developed to assist bridge designers in estimating steel I-section sizes for contract bidding.

DSP improvement of a vector speed induction motor control with a RST and adaptive fuzzy controller

The aim of this work is to improve the dynamics and to overcome the limitation of conventional fixed parameters PI controller used in induction motor (IM) field-oriented control (FOC). This study presents and implements a RST and an adaptive fuzzy controller (AFC) to enhance variable speed control. Theoretical background of theses controllers is outlined and then experimental results are presented. Practical implementation has been realized on a board with a 1.1 KW IM supplied by 10 KHz space vector pulse width modulation current regulated inverter used as power amplifier consisted of 300V, 10A IGBT and Matlab/Simulink environment. Test benches have been established under different operating conditions in order to evaluate and compare the performances of the PI, IP, and polynomial RST and adaptive fuzzy controllers. Parameter variations for the rotor and the inertia moment variation were done in order to compare and verify the robustness of each controller. High dynamic performances and robustness against parameters variation were obtained with the use of both RST and AFC.