To investigate the impacts of an energy efficiency retrofit, indoor air quality and resident health were evaluated at a low-income senior housing apartment complex in Phoenix, Arizona, before and after a green energy building renovation. Indoor and outdoor air quality sampling was carried out simultaneously with a questionnaire to characterize personal habits and general health of residents. Measured indoor formaldehyde levels before the building retrofit routinely exceeded reference exposure limits, but in the long-term follow-up sampling, indoor formaldehyde decreased for the entire study population by a statistically significant margin. Indoor PM levels were dominated by fine particles and showed a statistically significant decrease in the long-term follow-up sampling within certain resident subpopulations (i.e. residents who report smoking and residents who had lived longer at the apartment complex). Practical ImplicationsThe results presented here provide insight into the indoor air quality before, immediately after, and 1 year after an energy efficiency retrofit on a federal-subsidized senior apartment complex. With increasing focus on building energy efficiency, it is critical to evaluate possible relationships between resident health and changes in indoor environmental quality. Initially, formaldehyde exposure was quite high for all study participants, but an overall decrease was measured a year after the construction was completed. Particulate matter, however, was largely impacted by resident behavior (such as smoking), and a long-term decrease was only observed when combined with particular subpopulations.

The time dependence of the gaseous unimolecular decomposition of the jet-cooled adduct ion, Ni+-OC(CH3)2, was monitored through selective detection of the Ni+CO fragment ion. Various resolved amounts of energy in the range 15600-18800 cm(-1) were supplied to initiate the dissociation reaction through absorption of laser photons by the title molecular complex. First-order rate constants, k(E), ranged from 113000 to 55000 s(-1) and decreased with decreasing amounts of internal excitation. The energy used to initiate the reaction is well below that required to fragment C-C sigma bonds and indicates the necessity of the Ni+ cation to induce bond activation and fragmentation. These measurements are carried out in a unique apparatus and represent the first direct kinetic study of such catalytic type reactions.

Rate constants for the low-energy Ni(+)-assisted C-C bond cleavage reaction of deuterium-labeled acetone have been acquired under jet-cooled conditions in the gas phase. The energies used to initiate the dissociative reactions of the precursor complex ion Ni(+)(d(6)-Ac) are well below that required to cleave C-C sigma-bonds in isolated organic molecules. The rate constants are compared to those acquired previously for the lighter Ni(+)(h(6)-Ac) isotope and result in a substantial kinetic isotope effect (k(H)/k(D) approximately 5.5). Arguments are made that implicate isomerization leading to C-C bond coupling as the rate-limiting step (not C-C sigma-bond activation) in the dissociative reaction.

The A 2 − X 2 + (0,0) band system of barium monofluoride (BaF) has been recorded using high-resolution laser-induced fluorescence spectroscopy both field-free and in the presence of static magnetic and electric fields. The field-free spectra for the 135 BaF, 137 BaF, and 138 BaF isotopologues were modeled to generate an improved set of spectroscopic constants for the A 2 (υ = 0) and X 2 + (υ = 0) states. The observed optical Stark shifts for the 138 BaF isotopologue were analyzed to produce the permanent electric dipole moments of 1.50(2) and 1.31(2) D for the A 2 1/2 (υ = 0) and A 2 3/2 (υ = 0) states, respectively. The observed optical Zeeman shifts for the 138 BaF isotopologue were analyzed to produce a set of magnetic g factors for the A 2 (υ = 0) and X 2 + (υ = 0) states.

No abstract