Spectral Analysis of the Acoustic Signal During Ablation of Biological Tissue with Pulsed CO2- Lasers

Author(s):  
Hendrik Steigerwald ◽  
Martin Werner ◽  
Manfred Klasing ◽  
Mikhail Ivanenko ◽  
Daniela Harbecke ◽  
...  
Author(s):  
A.V Bublikov ◽  
P.I Pilov ◽  
N.S Pryadko ◽  
Yu.A Papaika ◽  
K.V. Ternova

Purpose. Increasing the jet mill productivity by use of automatic control of the grinding chamber filling level based on the acoustic monitoring results of the jet grinding process. Methodology. Simulation is performed in MATLAB. Acoustic signals of the mill operating zones are used to determine the grinding process parameters. Findings. A simulation model of the automatic jet mill control system is created, which takes into account the inertia of material flows in the grinding chamber and classifier, as well as the main disturbing influences on the process of forming the mill output flow. To analyze the control process, there are three main parts the information component (regulator and technical means of automation), a set of mathematical models that describe the physical processes in the grinding chamber and in the classifier. A study on the automatic control process of the grinding chamber filling is made under the condition of determining the controlled value indirectly through spectral analysis of the acoustic signal in the mill. The insignificant influence of perturbations on the controlled quantity due to very slow filling of the chamber with material in comparison with the period of stream fluctuations at a chamber entrance owing to perturbation action is shown. Originality. For the first time the possibility has been proved of using a relay regulator in control of the grinding chamber filling, determined indirectly through spectral analysis of the acoustic signal in a jet mill. The efficiency of the mill operation at automatic control of the grinding chamber filling according to the relay law is investigated. Practical value. It is shown that with the transition from automated to automatic control of the grinding chamber filling, the mill productivity increases by 1015%. The obtained results are used to build a system of automatic jet mill control.


Author(s):  
T. E. Hutchinson ◽  
D. E. Johnson ◽  
A. C. Lee ◽  
E. Y. Wang

Microprobe analysis of biological tissue is now in the end phase of transition from instrumental and technique development to applications pertinent to questions of physiological relevance. The promise,implicit in early investigative efforts, is being fulfilled to an extent much greater than many had predicted. It would thus seem appropriate to briefly report studies exemplifying this, ∿. In general, the distributions of ions in tissue in a preselected physiological state produced by variations in the external environment is of importance in elucidating the mechanisms of exchange and regulation of these ions.


Author(s):  
K. N. Colonna ◽  
G. Oliphant

Harmonious use of Z-contrast imaging and digital image processing as an analytical imaging tool was developed and demonstrated in studying the elemental constitution of human and maturing rabbit spermatozoa. Due to its analog origin (Fig. 1), the Z-contrast image offers information unique to the science of biological imaging. Despite the information and distinct advantages it offers, the potential of Z-contrast imaging is extremely limited without the application of techniques of digital image processing. For the first time in biological imaging, this study demonstrates the tremendous potential involved in the complementary use of Z-contrast imaging and digital image processing.Imaging in the Z-contrast mode is powerful for three distinct reasons, the first of which involves tissue preparation. It affords biologists the opportunity to visualize biological tissue without the use of heavy metal fixatives and stains. For years biologists have used heavy metal components to compensate for the limited electron scattering properties of biological tissue.


2008 ◽  
Author(s):  
Ji Ha Lee ◽  
Sung Won Choi ◽  
Ji Sun Min ◽  
Eun Ju Jaekal ◽  
Gyhye Sung

1953 ◽  
Author(s):  
C. J. Burke ◽  
R. Narasimhan ◽  
O. J. Benepe

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