scholarly journals Hydrodynamic model for UV laser ablation of polymers

1999 ◽  
Vol 17 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Y.V. AFANASIEV ◽  
V.A. ISAKOV ◽  
I.N. ZAVESTOVSKAYA ◽  
B.N. CHICHKOV ◽  
F. VON ALVENSLEBEN ◽  
...  
Keyword(s):  
Phase Transition ◽  
Laser Ablation ◽  
Theoretical Description ◽  
Hydrodynamic Equations ◽  
Uv Laser ◽  
Hydrodynamic Models ◽  
Surface Evaporation ◽  
Vapor Plume ◽  
Analytical Expressions ◽  
Good Agreement

The applicability of hydrodynamic models for theoretical description of UV laser ablation of polymers is studied. The plume formation is considered as a first-kind phase transition. In case of strongly absorbing polymers this phase transition occurs as a surface evaporation, and in case of weakly absorbing polymers as a bulk evaporation. The vapor plume is assumed to be transparent for laser radiation, and its expansion is described by the isoentropic hydrodynamic equations. New analytical expressions for ablation (etch) depths per pulse are obtained, which are in good agreement with the available experimental data (Afanasiev et al. 1997).

scholarly journals Simulation of laser ablation of metals for nanoparticles production

2016 ◽  
Vol 41 ◽  
pp. 1660143 ◽  
Author(s):  
R. V. Davydov ◽  
V. I. Antonov ◽  
T. I. Davydova
Keyword(s):  
Experimental Data ◽  
Laser Ablation ◽  
Femtosecond Laser Ablation ◽  
Hydrodynamic Equations ◽  
Temperature Model ◽  
Wide Range ◽  
Simulation Results ◽  
Range Equation ◽  
Two Temperature ◽  
Good Agreement

In this paper a mathematical model for femtosecond laser ablation of metals is proposed, based on standard two-temperature model connected with 1D hydrodynamic equations. Wide-range equation of state has been developed. The simulation results are compared with experimental data for aluminium and copper. A good agreement for both metals with numerical results and experiment shows that this model can be employed for choosing laser parameters to better accuracy in nanoparticles production by ablation of metals.

On biological signaling

2020 ◽  
Vol 75 (6) ◽  
pp. 507-509 ◽  
Author(s):  
Günter Nimtz ◽  
Horst Aichmann
Keyword(s):  
Phase Transition ◽  
Alternative Model ◽  
Pulse Propagation ◽  
Membrane Surface ◽  
Bound Water ◽  
Theoretical Description ◽  
Lyotropic Liquid Crystal ◽  
Local Phase ◽  
Electric Action ◽  
Nerve Pulse

AbstractPresently, nerve pulse propagation is understood to take place by electric action pulses. The theoretical description is given by the Hodgkin-Huxley model. Recently, an alternative model was proclaimed, where signaling is carried out by acoustic solitons. The solitons are built by a local phase transition in the lyotropic liquid crystal (LLC) of a biologic membrane. We argue that the crystal structure arranging hydrogen bonds at the membrane surface do not allow such an acoustic soliton model. The bound water is a component of the LLC and the assumed phase transition represents a negative entropy step.

scholarly journals Lithography and Etching‐Free Microfabrication of Silicon Carbide on Insulator Using Direct UV Laser Ablation

2020 ◽  
Vol 22 (4) ◽  
pp. 1901173
Author(s):  
Tuan‐Khoa Nguyen ◽  
Hoang-Phuong Phan ◽  
Karen M. Dowling ◽  
Ananth Saran Yalamarthy ◽  
Toan Dinh ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Laser Ablation ◽  
Uv Laser

scholarly journals Structural elastic and thermal properties of SrxCd1−x O mixed compounds — a theoretical approach

2014 ◽  
Vol 32 (3) ◽  
pp. 350-357
Author(s):  
Purvee Bhardwaj
Keyword(s):  
Phase Transition ◽  
Vibrational Energy ◽  
Zero Point ◽  
Study Phase ◽  
Energy Effect ◽  
Phase Transition Pressure ◽  
Vegard’S Law ◽  
Extended Interaction ◽  
Experimental Values ◽  
Good Agreement

AbstractIn the present paper, the structural and mechanical properties of alkaline earth oxides mixed compound SrxCd1−x O (0 ≤ x ≤ 1) under high pressure have been reported. An extended interaction potential (EIP) model, including the zero point vibrational energy effect, has been developed for this study. Phase transition pressures are associated with a sudden collapse in volume. Phase transition pressure and associated volume collapses [ΔV (Pt)/V(0)] calculated from this approach are in good agreement with the experimental values for the parent compounds (x = 0 and x = 1). The results for the mixed crystal counterparts are also in fair agreement with experimental data generated from the application of Vegard’s law to the data for the parent compounds.

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