Fabrication of PVDF/PMMA Polymer for Sustainable Energy Harvesting .

JOSE RAYMUNDO LEPPE NEREY FERNANDO ZENAIDO SIERRA ESPINOSA MIGUEL ANGEL BASURTO PENSADO JOSE ALFREDO RODRIGUEZ RAMIREZ (2023)

The synthesis of blends that combine properties of two or more polymeric materials is increasingly investigated due to the versatility of the synthesis and its growing potential for many applications, including sustainability. Their characteristics are defined mainly by the synthesis conditions. Therefore, this paper details the synthesis process of easy-to-handle films using mixing method. The procedures and drawbacks found during the preparation of composite films are described. Polymeric compounds formed by the mixture of polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) are addressed, varying the concentration, and evaluating their impact on the piezoelectric capacity. Films were formed through the spin-coating technique and characterized by optical and holographic microscopes. The results showed that composites with a concentration of 50 wt.% or larger of PVDF in the blend acquire a morphology with a granular appearance, however at lower concentrations they present a homogeneous morphology similar to that of PMMA. A homogeneous distribution of PVDF in the PMMA stands out. However, excessive contents of PMMA are associated to peaks and non-uniformities detected like multicolored regions by digital holography. Controlled strength-strain laboratory tests allowed to evaluate the film blends performance. The results indicate noticeable improvements in voltage output for a composition 70wt% PVDF and 30 wt% PMMA.

Artículo

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS Polymer blends, Power generation, Energy harvesting, Piezoelectricity,

Analysis of Gas Turbine Combustor Exhaust Emissions:Effects of Transient Inlet Air Pressure

FERNANDO ZENAIDO SIERRA ESPINOSA JUAN CARLOS GARCIA CASTREJON JOSE ALFREDO RODRIGUEZ RAMIREZ (2024)

Gas turbine combustors are often subjected to combustion instabilities because

of variability of operating conditions, affecting components, and altering exhaust

emissions. Herein, the analysis focuses on simulating numerically the non-premixed

combustion as unsteady flamelet combustion and detailed kinetic

mechanism. The goal is analyzing exhaust gases under unsteady inlet airflow

conditions to define operation guidelines. The numerical approach is validated

using data from the literature for nonperturbed cases. Three periodical perturbations

of different amplitude show differences with the nonperturbed case.

Besides emission of exhaust gases, the temperature field is sensitive to airflow

inlet conditions. According to the simulation results, a strong dependence of

temperature and pressure in primary and dilution zones of combustor exists on

the inlet air pressure condition. Emissions of flue gases like CO and NOx respond

to combustor thermal behavior showing high sensitivity to inlet air pressure as

well. Results indicate that moderate pressure oscillations may derive into

flashback effects.

Artículo

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS