Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(537 6). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Universitat Rovira i Virgili

1. Amat Genís, Albert. Effect of visible and near-infrared light on adenosine triphosphate (atp).

Degree: Departament de Ciències Mèdiques Bàsiques, 2005, Universitat Rovira i Virgili

ATP is a key molecule in cellular metabolism. In this thesis, I examined the effects of visible (635 and 655 nm) and near-infrared (810 and 830 nm) light on ATP in solution. I also examined were the biochemical behavior of light-exposed ATP in the luciferine-luciferase reaction and hexokinase reaction, the initial step in glycolysis that begins extra mithocondrial ATP synthesis. Irradiated groups in the luciferine-luciferase reaction showed an improvement in the kinetic parameters V0 and k, and more ATP molecules reacted with the enzyme when they were excited by light. When irradiated ATP was added to the hexokinase reaction, the experimental groups showed significant differences in the Michaelis-Menten kinetic parameters (km for ATP and vmax) and the rate of product synthesis was greater. Changes in both reactions were wavelength and dose dependant. When ATP was excited with UV photons, it fluoresced. This fluorescence decreased when Mg2+ was added, probably because the ion binds the phosphates, which are the part of the molecule responsible for light emission. Irradiating the ATP-Mg2+ solution with 655 nm and 830 nm light increased the fluorescence resulting from a displacement of charges in the phosphor-oxygen bond that repels Mg2+. The refraction of light in an ATP solution was observed by the Michelson interferometer and by directly measuring the refractive index. The refractive index changed after red and near-infrared light interaction due to a change in the electrical permittivity of the medium. Since ATP in water is transparent to visible and near-infrared light, and is therefore not a chromophore for those wavelengths, I conclude that the observed light interaction with ATP is not due to photon absorption but to the electromagnetic disturbance produced by the light, which leads to a polarization of the dielectric molecule that is ATP. This interaction of visible and near-infrared electromagnetic energy with ATP offers new perspectives for explaining light interaction at subcellular level. Advisors/Committee Members: [email protected] (authoremail), true (authoremailshow), Rigau Mas, Josepa (director).

Subjects/Keywords: refractive index; adenosine triphosphate (atp); Laser; 537; 577; 6; 61

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Amat Genís, A. (2005). Effect of visible and near-infrared light on adenosine triphosphate (atp). (Thesis). Universitat Rovira i Virgili. Retrieved from http://hdl.handle.net/10803/8715

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Amat Genís, Albert. “Effect of visible and near-infrared light on adenosine triphosphate (atp).” 2005. Thesis, Universitat Rovira i Virgili. Accessed April 11, 2021. http://hdl.handle.net/10803/8715.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Amat Genís, Albert. “Effect of visible and near-infrared light on adenosine triphosphate (atp).” 2005. Web. 11 Apr 2021.

Vancouver:

Amat Genís A. Effect of visible and near-infrared light on adenosine triphosphate (atp). [Internet] [Thesis]. Universitat Rovira i Virgili; 2005. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10803/8715.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Amat Genís A. Effect of visible and near-infrared light on adenosine triphosphate (atp). [Thesis]. Universitat Rovira i Virgili; 2005. Available from: http://hdl.handle.net/10803/8715

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Bonache Samaniego, Ricardo. Self-oscillating resonant converters: general approach and applications.

Degree: Departament d'Enginyeria Electrònica, Elèctrica i Automàtica, 2017, Universitat Rovira i Virgili

In this thesis, self-oscillation in resonant converters is generated by the appropriate use of the input inductor current zero-crossings to change the polarity of the input voltage. As a result, the input current and the first harmonic of the input voltage are in phase, which ensures a unity power factor to the steady-state operation of the resonant converter. This fact confers a nature of loss-free resistor (LFR) on the two-port description of the converter. The self-oscillation generating mechanism is proven to be effective in second, third and fourth order structures. Although the self-oscillation generation is a relatively simple task, the analytical description of the generation is more involved. It combines time-domain and frequency-domain analyses to justify that a spiral starting from zero initial conditions eventually converges into an ellipse that corresponds to the steady-state behavior of the limit cycle. The stability of the generation is demonstrated by proving the stability of the resulting discrete recurrence considering two successive zero-crossings of the input inductor current after completing a generic oscillation cycle. This approach successfully explains the generation of two-dimension and three-dimension spirals in second and third order converters respectively. Self-oscillating resonant converters with the previous mechanism to generate oscillations are a simple procedure to transmit power but they are sensitive to input voltage perturbations or load changes. Hence, a voltage regulation loop has to be added. Inserting a voltage regulation loop requires modeling the dynamic behavior of the self-oscillating resonant converter whose switching law is a linear combination of inductor current and capacitor voltage. Relating the variations of the constant of that linear combination to the changes of the switching frequency is the key aspect of the modeling, which is carried out for second order converters. The resulting closed-loop regulation exhibits larger bandwidth and a better robustness degree than conventional controllers. Advisors/Committee Members: [email protected] (authoremail), true (authoremailshow), Olalla Martínez, Carlos (director), Martínez Salamero, Luis (director), true (authorsendemail).

Subjects/Keywords: Auto-oscil·lació; Convertidors resonants; Sistemes estructura variable; Auto-oscilación; Convertidores resonantes; Sistemas estructura variable; Self-oscillation; Resonant converters; Variable structure systems; Enginyeria i Arquitectura; 00; 537; 6; 62

…128 5.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 6 Fourth… …ZCS) and soft-switching [6] were also mentioned during those decades, though… …the resonant frequency f0 , identified as 6 UNIVERSITAT ROVIRA I VIRGILI SELF-OSCILLATING… …implementation of a practical application based on a LCC converter. Finally, in Chapter 6 the previous… 

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Bonache Samaniego, R. (2017). Self-oscillating resonant converters: general approach and applications. (Thesis). Universitat Rovira i Virgili. Retrieved from http://hdl.handle.net/10803/402466

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Bonache Samaniego, Ricardo. “Self-oscillating resonant converters: general approach and applications.” 2017. Thesis, Universitat Rovira i Virgili. Accessed April 11, 2021. http://hdl.handle.net/10803/402466.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Bonache Samaniego, Ricardo. “Self-oscillating resonant converters: general approach and applications.” 2017. Web. 11 Apr 2021.

Vancouver:

Bonache Samaniego R. Self-oscillating resonant converters: general approach and applications. [Internet] [Thesis]. Universitat Rovira i Virgili; 2017. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10803/402466.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Bonache Samaniego R. Self-oscillating resonant converters: general approach and applications. [Thesis]. Universitat Rovira i Virgili; 2017. Available from: http://hdl.handle.net/10803/402466

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.