arXiv subjects

Mohsen Salimi

Publications and source records attributed to Mohsen Salimi.

3 recordsLinked to original sources

arXiv2026

Single-run determination of the saturation vapor pressure and enthalpy of vaporization/sublimation of a substance undergoing successive solid-solid and solid-liquid phase transitions: the case of $N$-methyl acetamide

We report on the dynamical measurement of the saturation vapor pressure of $N$-methyl acetamide in the temperature range $-30^\circ$C to $34^\circ$C. This is achieved by monitoring the pressure inside a vacuum chamber in which a precooled sample of the substance slowly thermalizes to the chamber temperature, undergoing first a phase transition between two crystalline structures around $1^\circ$C and then a solid-liquid phase transition around $30^\circ$C. Such a measurement provides in a single run accurate data for the saturation vapor pressure and the enthalpies of sublimation and vaporization of the different phases of the investigated substance.

physics.chem-ph↗

arXiv2025

Dynamical measurement of saturation vapor pressures below and above room temperature

We report on the implementation of a dynamical method for the determination -- in an extended temperature range around room temperature -- of the saturation vapor pressure and enthalpy of vaporization of low-volatility liquid substances. The method relies on isolating a \textit{precooled} substance in a heated chamber under static vacuum conditions and monitoring the chamber pressure as the sample slowly thermalizes to the chamber temperature. We apply the method to four reference substances -- diethyl phthalate, 1-decanol, 1-heptanol, and 1-hexanol -- and provide accurate data for their saturation vapor pressure and enthalpy of vaporization in the range from $-10$ to $35^\circ$C.

physics.chem-ph↗

arXiv2024

Squeeze film absolute pressure sensors with sub-millipascal sensitivity

We report on the realization of ultrasensitive absolute pressure sensors based on silicon nitride membrane sandwiches. These sandwiches consist in a pair of highly-pretensioned, ultrathin (50 nm), large area (0.25 mm2) films, suspended parallel to each other and forming an ultrashort (500 nm), open cavity. The compression of a gas in this cavity leads to a strong squeeze film force, resulting in an increase in the membrane mechanical resonance frequencies which is directly proportional to the absolute gas pressure. These sandwiches show a record high responsitivity of >300 Hz/Pa in terms of squeeze film-induced frequency shift, which, combined with high quality factor mechanical resonances (Q>10^6), allows for bringing the sensitivity of absolute squeeze film pressure sensors down to the sub-millipascal level.

physics.app-ph↗