scholarly journals Sequential Photodamage Driven by Chaotic Systems in NiO Thin Films and Fluorescent Human Cells

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1377
Author(s):  
Hilario Martines-Arano ◽  
Mónica Araceli Vidales-Hurtado ◽  
Samara Palacios-Barreto ◽  
Martín Trejo-Valdez ◽  
Blanca Estela García-Pérez ◽  
...  
Keyword(s):  
Processing Technique ◽  
Human Cells ◽  
Flip Flop ◽  
Optical Signals ◽  
Laser Ablation Process ◽  
Thermal Phenomenon ◽  
Potential Applications ◽  
Two Wave Mixing ◽  
Mixing Method ◽  
532 Nm

A laser ablation process assisted by the feedback of a sensor with chaotic electronic modulation is reported. A synchronous bistable logic circuit was analyzed for switching optical signals in a laser-processing technique. The output of a T-type flip-flop configuration was employed in the photodamage of NiO films. Multiphotonic effects involved in the ablation threshold were evaluated by a vectorial two-wave mixing method. A photoinduced thermal phenomenon was identified as the main physical mechanism responsible for the nonlinearity of index under nanosecond irradiation at 532 nm wavelength. Comparative experiments for destroying highly transparent human cells were carried out. Potential applications for developing hierarchical functions yielding laser-induced controlled explosions with immediate applications for biomedical photothermal processes can be contemplated.

Development of Ultra-Fine Microstructure in Titanium via Powder Metallurgy for Improved Ductility and Strength

2008 ◽  
Vol 604-605 ◽  
pp. 223-228 ◽  
Author(s):  
Daniel Eylon ◽  
William A. Ernst ◽  
Daniel P. Kramer
Keyword(s):  
Permanent Magnets ◽  
Rapid Heating ◽  
Fine Powder ◽  
Processing Technique ◽  
Grain Structure ◽  
Fine Microstructure ◽  
Potential Applications ◽  
Grade 3 ◽  
Ti Powder ◽  
Cp Ti

In an effort to produce an ultra-fine alpha titanium equiaxed grain structure, suitable for superplastic deformation processes, Armstrong-Process CP Ti powder, was consolidated into compacts with grain-size on the order of 2 to 3 microns. This powder has very fine dendritic-shaped particles with an inherent sub-micron grain-structure. In order to preserve as much as possible the fine powder microstructural scale, the compaction was accomplished by rapid-heating and short-hold VHP, using a procedure derived from a processing technique originally developed at the University of Dayton for producing nano-phase hard permanent magnets. It was modified to suit the titanium powder, and a range of parameters was experimented to produce a variation of microstructures. One set of compaction conditions resulted in the desired microstructure, and subsequent tensile testing demonstrated strength and ductility exceeding CP Ti Grade 3, due to the ultra-fine equiaxed alpha grain structure. The paper will discuss the various microstructures and the potential applications.

scholarly journals Toward Non-Invasive Measurement of Atmospheric Temperature Using Vibro-Rotational Raman Spectra of Diatomic Gases

2020 ◽  
Vol 12 (24) ◽  
pp. 4129
Author(s):  
Tyler Capek ◽  
Jacek Borysow ◽  
Claudio Mazzoleni ◽  
Massimo Moraldi
Keyword(s):  
Continuous Wave ◽  
Molecular Nitrogen ◽  
Atmospheric Temperature ◽  
Precise Determination ◽  
Gas Temperature ◽  
Advantages And Disadvantages ◽  
Non Invasive ◽  
Potential Applications ◽  
532 Nm

We demonstrate precise determination of atmospheric temperature using vibro-rotational Raman (VRR) spectra of molecular nitrogen and oxygen in the range of 292–293 K. We used a continuous wave fiber laser operating at 10 W near 532 nm as an excitation source in conjunction with a multi-pass cell. First, we show that the approximation that nitrogen and oxygen molecules behave like rigid rotors leads to erroneous derivations of temperature values from VRR spectra. Then, we account for molecular non-rigidity and compare four different methods for the determination of air temperature. Each method requires no temperature calibration. The first method involves fitting the intensity of individual lines within the same branch to their respective transition energies. We also infer temperature by taking ratios of two isolated VRR lines; first from two lines of the same branch, and then one line from the S-branch and one from the O-branch. Finally, we take ratios of groups of lines. Comparing these methods, we found that a precision up to 0.1 K is possible. In the case of O2, a comparison between the different methods show that the inferred temperature was self-consistent to within 1 K. The temperature inferred from N2 differed by as much as 3 K depending on which VRR branch was used. Here we discuss the advantages and disadvantages of each method. Our methods can be extended to the development of instrumentation capable of non-invasive monitoring of gas temperature with broad potential applications, for example, in laboratory, ground-based, or airborne remote sensing.

The Fabrication and Property of PTFE-NP Liquid Marbles

2012 ◽  
Vol 465 ◽  
pp. 136-140
Author(s):  
Shao Peng Wang ◽  
Bing Yu ◽  
Hai Lin Cong ◽  
Xue Bai
Keyword(s):  
Drug Delivery ◽  
Water Purification ◽  
Powder Materials ◽  
Liquid Drops ◽  
Liquid Marbles ◽  
Delivery Water ◽  
Potential Applications ◽  
New Type ◽  
Mixing Method

Liquid marbles are hydrophilic liquid drops encapsulated with hydrophobic powder materials. The liquid marbles have potential applications in drug delivery, water purification, ferrofluidic device and sensor microfabrication. In this work, a new type of polytetrafluoroethylene nanoparticle (PTFE-NP) liquid marbles were fabricated successfully using mixing method. The morphology of the formed liquid marbles was characterized under different conditions, and novel properties of the PTFE-NP liquid marbles were investigated and demonstrated.

scholarly journals Photoconductive Multiplexing by ZnO:Zr:F Thin Solid Films

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
C. Torres-Torres ◽  
L. Castañeda ◽  
R. Torres-Martínez
Keyword(s):  
Nonlinear Optical ◽  
Laser System ◽  
Optical Nonlinearity ◽  
Spectroscopic Studies ◽  
Photon Absorption ◽  
Zno Films ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Two Wave Mixing ◽  
Mixing Method

Within this work, the nonlinear optical properties and electrical effects exhibited by zinc oxide thin films codoped with zirconium and fluorine are reported. The development of a simple photoconductive multiplexor system is proposed. The samples were prepared by the ultrasonic spraying technique (UST). Spectroscopic studies and a vectorial two-wave mixing method were carried out with a nanosecond Nd:YAG laser system at 532 nm. Experimental results indicate that after the zirconium and fluorine doping, a strong third-order optical nonlinearity can be developed in the ZnO films. The nonlinear optical response seems to be dominantly originated by a two-photon absorption closely related to a photoconductive phenomenon.

Multi-Functional Silica Nanoparticles Based on Metal Atom Clusters: From Design to Toxicological Studies

2014 ◽  
Vol 617 ◽  
pp. 179-183
Author(s):  
Tangi Aubert ◽  
Nicolas Nerambourg ◽  
Chrystelle Neaime ◽  
Francisco Cabello-Hurtado ◽  
Marie Andrée Esnault ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Metal Atom ◽  
Risk Evaluation ◽  
Human Cells ◽  
Hybrid Nanoparticles ◽  
Gold Nanocrystals ◽  
Atom Clusters ◽  
Toxicological Studies ◽  
Potential Applications

We report on the interest of luminescent and nanosized metal atom clusters for the development of functional silica nanoparticles. Furthermore, multi-functional hybrid nanoparticles have been achieved by associating these luminescent clusters with magnetic γ-Fe2O3 nanocrystals and plasmonic gold nanocrystals. In addition, as part of the risk evaluation before potential applications, the toxicity of the nanoparticles was evaluated both on plants and on human cells.

scholarly journals Controlling hybrid nonlinearities in transparent conducting oxides via two-colour excitation

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Clerici ◽  
N. Kinsey ◽  
C. DeVault ◽  
J. Kim ◽  
E. G. Carnemolla ◽  
...  
Keyword(s):  
Optical Pulse ◽  
Temporal Dynamics ◽  
Dynamic Control ◽  
Modulation Bandwidth ◽  
Optical Signals ◽  
Conducting Oxides ◽  
Transparent Conducting ◽  
Potential Applications ◽  
New Material ◽  
At Will

Abstract Nanophotonics and metamaterials have revolutionized the way we think about optical space (ɛ,μ), enabling us to engineer the refractive index almost at will, to confine light to the smallest of the volumes, and to manipulate optical signals with extremely small footprints and energy requirements. Significant efforts are now devoted to finding suitable materials and strategies for the dynamic control of the optical properties. Transparent conductive oxides exhibit large ultrafast nonlinearities under both interband and intraband excitations. Here we show that combining these two effects in aluminium-doped zinc oxide via a two-colour laser field discloses new material functionalities. Owing to the independence of the two nonlinearities, the ultrafast temporal dynamics of the material permittivity can be designed by acting on the amplitude and delay of the two fields. We demonstrate the potential applications of this novel degree of freedom by dynamically addressing the modulation bandwidth and optical spectral tuning of a probe optical pulse.

scholarly journals Nonlinear Mechanooptical Transmittance Controlled by a Rotating TiO2 Thin Solid Film with Embedded Bimetallic Au-Pt Nanoparticles

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
A. J. Piña-Díaz ◽  
M. Trejo-Valdez ◽  
S. Morales-Bonilla ◽  
C. R. Torres-San Miguel ◽  
C. L. Martínez-González ◽  
...  
Keyword(s):  
Laser System ◽  
Sol Gel ◽  
Pt Nanoparticles ◽  
Optical Transmittance ◽  
Thin Solid Film ◽  
Third Order ◽  
Transmission Electron ◽  
Potential Applications ◽  
Two Wave Mixing ◽  
Solid Film

The modification in the third-order nonlinear optical behavior exhibited by a titanium dioxide thin solid film with embedded Gold-Platinum nanoparticles was induced by nanosecond optical pulses. A Nd:YAG laser system was employed for the experiments explored by a vectorial two-wave mixing method with the sample in rotation. The nanostructures were prepared by a sol-gel technique. Transmission Electron Microscopy studies and ultraviolet-optical spectroscopy measurements were undertaken. The evolution of the optical transmittance exhibited by the sample in rotation controlled by a servomechanism was observed. Potential applications for developing mechanooptical functions based on third-order optical nonlinearities were contemplated.

Mechanical Alloying of Ti-Based Materials

2018 ◽  
Vol 770 ◽  
pp. 95-105 ◽  
Author(s):  
Hilda Chikwanda ◽  
L. Mahlatji
Keyword(s):  
Mechanical Alloying ◽  
Powder Processing ◽  
High Energy ◽  
Processing Technique ◽  
Dispersion Strengthening ◽  
High Energy Ball Mill ◽  
Potential Applications ◽  
Powder Particles ◽  
Energy Ball ◽  
Metastable Effects

Mechanical alloying (MA) is a simple and versatile dry powder processing technique that has been used for the manufacture of both equilibrium and metastable phases of commercially useful and scientifically interesting materials. It owes its origin to an industry need to develop a nickel-based super alloy for gas turbine applications that had both oxide dispersion strengthening and precipitation hardening. This far-from equilibrium powder metallurgy processing technique involves fracturing, welding and re-welding of powder particles in a High Energy Ball Mill (HEBM). MA is an economically viable process with important technical advantages. Its utmost advantage is in the synthesis of novel alloys, e.g., alloying of ordinarily immiscible elements, that is not possible by any other technique. As MA is a completely solid-state processing technique, the limitations imposed by phase diagrams do not apply to it. The MA process is capable of producing different types of metastable effects in a variety of alloy systems. Some of the metastable effects achieved by MA are solid solution formation and amorphisation. MA has the possibility of producing superior and enhanced materials than those produces by conventional methods. In this work a review of MA and its present and potential applications for Ti-based materials are presented.

scholarly journals Enhanced photoresponse of highly air-stable palladium diselenide by thickness engineering

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2467-2474 ◽  
Author(s):  
Jing Wu ◽  
Yunshan Zhao ◽  
Minglei Sun ◽  
Minrui Zheng ◽  
Gang Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Optoelectronic Properties ◽  
First Principles Calculation ◽  
Next Generation ◽  
Promising Candidate ◽  
Band Engineering ◽  
Potential Applications ◽  
532 Nm ◽  
Low Symmetry ◽  
Insight Into

AbstractRecently, layered two-dimensional (2D) palladium diselenide (PdSe2), with a unique low- symmetry puckered pentagon atomic morphology, has emerged as a promising candidate for next-generation nanoelectronics and optoelectronics because of its chemical stability and extraordinary electrical properties. Moreover, PdSe2 possesses a strong thickness-dependent bandgap that varies from 0 eV for bulk to 1.3 eV for monolayer, which can further render its potential applications in optoelectronics. However, the layer-dependent optoelectronic properties of PdSe2 are still lacking up to date. Herein, we studied the optoelectronics transport characteristics of high-quality PdSe2-based photodetectors with different thicknesses. We demonstrated an enhancement of PdSe2 photodetector performance owing to the band engineering via a thickness reduction. The highest responsivity of 5.35 A/W can be achieved with an external quantum efficiency of 1250% at the wavelength of 532 nm. We attribute such high performance in photoresponsivity to the high valley convergence in the conduction band of layered PdSe2, in agreement with first-principles calculation. Our results offer new insight into the layer-dependent optoelectronic properties of PdSe2 and open new avenues in engineering next-generation 2D-based electronics and optoelectronics.

A MULTIVIBRATOR CIRCUIT BASED ON CHAOS GENERATION

2012 ◽  
Vol 22 (01) ◽  
pp. 1250011 ◽  
Author(s):  
E. CAMPOS-CANTÓN ◽  
R. FEMAT ◽  
J. G. BARAJAS-RAMÍREZ ◽  
I. CAMPOS-CANTÓN
Keyword(s):  
Chaotic Systems ◽  
Pulse Generator ◽  
Piecewise Linear ◽  
Equilibrium Stability ◽  
Flip Flop ◽  
Chua’S Oscillator ◽  
Potential Applications ◽  
Bistable Potential ◽  
Linear Subsystem ◽  
Parametric Modulation

We present a parameterized method to design multivibrator circuits via piecewise-linear (PWL) chaotic systems, which can exhibit double-scroll oscillations. The circuit is conformed exploiting a parametric modulation that manipulates the equilibrium stability of each linear subsystem. Chua's oscillator is used as benchmark to illustrate the effectiveness of the proposed method to design multivibrator circuits. Thus, our proposal allows the design of the three configurations of a multivibrator: monostable, astable, and bistable. Potential applications are illustrated designing a pulse generator and a full S-R flip flop device based on our all-in-one multivibrator circuit.

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