Vapour pressures of hydroxybenzophenone UV absorbers

Vapour pressures of hydroxybenzophenone UV absorbers

A thermogravimetric method was used to measure the vapour pressures of a series of hydroxybenzophenone UV stabilisers. Enthalpies of vaporisation were determined from the slope of a plot of the logarithm of the vapour pressure against reciprocal absolute temperature. Enthalpies of sublimation were measured either directly by the same method or by summing the enthalpy of vaporisation with the en...

Estimating the vapour pressures of alpha-pinene products

Introduction Conclusions References Tables Figures Back Close Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Print Version Interactive Discussion EGU Abstract A prediction method based on group contribution principles is proposed for estimating the vapour pressure of α-pinene oxidation products. Temperature dependent contributions are provided for the f...

Investigations on Photostability of UV-Absorbers for Cosmetic Sunscreens

X-Ray Absorption Associated with High-Velocity UV Absorbers

We present Chandra observations of two radio-quiet QSOs, PG 2302+029 and PG 1254+047. PG2302+029 has an ultra high-velocity UV absorption system (∼ −56, 000 km s), while PG 1254+047 is a Broad Absorption Line (BAL) QSO with detached troughs. Both objects are X-ray weak, consistent with the known correlation between αox and the strength of the UV absorption lines. The data suggest that there is ...

Comments on the Intrinsic X-ray/uv Absorbers in Agn

This talk discusses the unified X-ray/UV absorption models in AGN. I will first review the models and discuss how they offer an unique opportunity to probe the near nuclear environment of AGNs. Recently, however, the validity of these models has been questioned by a number of authors. I will discuss these papers and argue that the data/ models presented in them do NOT contradict the unified X-r...