Simple analysis method of beam scanning characteristic of a subreflector-displaced reflector antenna

2003 ◽  
Author(s):  
K. Kagoshima
2015 ◽  
Vol 9 (12) ◽  
pp. 1279-1286 ◽  
Author(s):  
Ming Bai ◽  
Naiming Ou ◽  
Ming Jin ◽  
Jungang Miao

2004 ◽  
Author(s):  
Shaun Richmond

Vibration of attached components such as running boards, hand grabs, brake components, etc. has become a serious problem. This paper sets out a simple analysis method for ensuring the survival of these components. A simple mass spring model is used to develop a transfer function into the car body. The frequency components of a wheel flat and 39/33 foot jointed track are then established and the excitation amplitudes for components attached to the car body calculated. The response of these components at their natural frequency is then used to calculate their resulting stress levels. Simple methods for performing this analysis are described


Author(s):  
Yasutomo Kaneko ◽  
Kazushi Mori ◽  
Hiroharu Ohyama

This paper presents a simple analysis method for predicting vibration response characteristics of a bladed disk with continuous ring type structure losing a shroud or a shroud and a stab between two blades. This loss introduces a mistuning of the system and the whole bladed disk model must be used to conduct the study. However, the vibration modes change regularly from a sine and a cosine mode, if the bladed disk consists of many blades. By utilizing this phenomenon, the simple formulation of vibration response of a bladed disk can be derived. Second, the parametric study on the vibration response characteristics of a bladed disk losing a shroud or a shroud and a stab is carried out extensively, utilizing the analysis method proposed here. From the calculated results, the vibration response characteristics of a bladed disk are clarified for both of resonant vibration and random vibration. Lastly, the results calculated by the simple analysis method proposed are compared with the results obtained from FEA (Finite Element Analysis) in order to verify the validity of the analysis method.


2020 ◽  
Author(s):  
Hongwang Lu ◽  
Xin Ma

AbstractThe previous study has reported that the presence of a small flap in the Brown Long-Eared Bat (Plecotus auritus) generate useful spatial information by the frequency-driven beam scanning. However, it did not investigate the beampattern generating mechanism of the flap. In this study, according to the dipole equivalence principle, the two resonance cavities split by the flap are simplified to a dipole source with certain vibration orientation. The analytical solution of the dipole shows obvious frequency-driven sidelobe scanning in the beampattern, which matches the numerical results obtained from the pinna quite well. The results support the hypothesis that the frequency-driven sidelobe scanning is generated by the resonance in the two cavities split by the flap. This method can be applied to design a reflector antenna with small geometric structures for splitting existent resonance cavities to meet requirements of beam scanning.


2018 ◽  
Vol 69 (8) ◽  
pp. 1996-1999 ◽  
Author(s):  
Corina Marilena Cristache ◽  
Eugenia Eftimie Totu ◽  
Daniel Petre ◽  
Roxana Buga ◽  
Gheorghe Cristache ◽  
...  

The present work reports an efficient procedure for a simultaneous determination of melatonin (MEL) and hyaluronic acid (HA) mixture applying first derivative UV-Vis spectrophotometry. At selected wavelength (205 nm), the linearity range for each component of the mixture was established. The linear regression correlation coefficients for the direct UV-Vis spectra (RHA2 = 0.9627) and their first derivate (RHA2 = 0.9986) put in evidence a better fit for the derivative procedure. Through such simple analysis method, it was possible to emphasize that each component of MEL-HA mixture preserves its identity and characteristic properties. Consequently, the association of MEL and HA biomolecules could be used for obtaining a complex therapeutic agent with extensive applications in dental medicine.


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