Assessing the Effect of Dome Shape and Location on The Acoustical Performance of a Mosque by Using Computer Simulation

Architecturally, the dome is one evolutionary presence in most mosques of modern day. Besides mihrab, the dome is one of the architectural elements that has a phenomenon of concentration of energy by reflected sound waves from concave surfaces. The aim of this research is to compare the acoustical performance of different shapes of the dome and their respective locations by using geometrical approach computer simulation. Four types of dome that are commonly used on a mosque; Arabic, segmental, hemispherical, and onion, were modeled to compare their acoustical parameters i.e. reverberation time (RT) and speech transmission index (STI). It can be concluded that the shape of the dome does affect the RT. Furthermore, the shape of the dome also affects the STI - the larger the volume, the lower the STI value. However, the locations of a dome has little significance over acoustical parameter. The findings of this research may not limit to mosques only, but to any similar building that has similar typology.

Acustical Studies of Interactions in the Binary Mixtures of Ethylmethyl Ketone (EMK) and N,N-Dimethylformamide (DMF) through Ultrasonic Measurements at Different Temperatures

Ultrasonic velocities (u), densities (ρ) and viscosities (η) are measured in respect of ethylmethylketone (EMK) and N,N-dimethylformamide (DMF) over the entire composition at 298, 308and 318K. Attempt have been made to extract the information with respect to various kind of intermolecular interactions, such as H-bonding, dipole-dipole, solute –solvent, dispersion type interactions existing between these two components from the following acoustical parameter when examined as a function of solvent composition at different temperatures: adiabatic compressibility (β), specific acoustic impedance (Z), intermolecular free length (Lf), molar sound velocity (Rm), wada’s constant (W), viscous relaxation time (τ), free volume and internal pressure (πi).

Acoustic and Volumetric Properties of Digoxin and Thiabendazole in 1, 4 Dioxane at 303 K

Acoustical and volumetric properties have been measured for substituted heterocyclic compounds digoxin and thiabendazole in 1, 4 dioxane at 303 K. The ultrasonic velocity measurement have been performed to evaluate acoustical parameter such as adiabatic compressibility (βs), partial molal volume (ɸv), intermolecular free length (Lf), apparent molal compressibility (ɸk), specific acoustic impedance (Z), relative association (RA), salvation number (Sn), limiting apparent molal compressibility (ɸ0k), limiting apparent molal volume(ɸ0v) and their constant (Sk,Sv). The viscosity coefficient (A, B) was evaluated by using john–dole equation. These parameters throw the light on the solute-solvent interaction and solute-solute interaction.