Development of combustion chamber of a reference calorimeter with numerical analysis

<p class="Abstract">The present work focuses on the numerical modeling of two combustion chambers to be used inside an isoperibolic calorimeter to measure the Superior Calorific Value (SCV) from natural gas. This work shows performance of both chambers working under isoperibolic principle, through simulations based on Computational Fluid Dynamics (CFD). The aim of the work is expose the performance of chamber combustion published in the literature versus another one proposed in this work, and show how was improved the performance of the chamber which proposed in this work by changing the geometry. And it is checked by analyzing temperature of burned gases at exit of combustion chamber.</p>

Thermodynamic and Calorimetric Study of Acetylsalicylic Acid (Aspirin) and Ibuprofen

Enthalpies of solution and dilution of aqueous solutions of sodium acetylsalicylic acid salt and ibuprofen salt were measured with an isoperibolic calorimeter at 293.15 K, 298.15 K, 303.15 K, 308.15 K and 318.15 K. The concentration of the electrolyte was restricted to the solubility of the salt at various temperatures and did not exceed 0.035–0.057 mol kg-1, depending on the temperature studied. The Virial coefficients were derived from Pitzer's model and the excess thermodynamic functions of both the solution and the components of the solution were calculated. An analysis of the thermodynamic characteristics of the solution in terms of concentration and temperature interval was carried out and discussed. Additionally, an analysis was performed by differential scanning calorimetry (DSC).