following the changes in the paradigm of urban studies in recent years, sustainability has become an increasingly important issue in the neighborhood’s planning and designing. however, this concept has originally been developed for american and european neighborhoods’ planning, it could also be customized for other neighborhoods’. additionally, in the neighborhood scale, the quality parameter f...

Peng et al. (1) conclude that a fast increase in the mass absorption cross-section (MAC) of black carbon (BC) in urban environments leads to significantly increased estimates of the BC radiative forcing (RF). Their chamber measurements are highly valuable and complement observations performed in ambient conditions, but their “enhancement factor” relative to an unspecified baseline may not be di...

We have completed a series of measurements that provide a basic understanding of the properties of CsI photocathodes for use in ring imaging Cherenkov (RICH) detectors. The quantum efficiency of CsI has been measured relative to an NIST-calibrated photodiode and is in excellent agreement with a similar measurement by Breskin et al. A representative value of the quantum efficiency is 20% at 180 ...

Organic substances can adopt an amorphous solid or semisolid state, influencing the rate of heterogeneous reactions and multiphase processes in atmospheric aerosols. Here we demonstrate how molecular diffusion in the condensed phase affects the gas uptake and chemical transformation of semisolid organic particles. Flow tube experiments show that the ozone uptake and oxidative aging of amorphous...

We present a model where an unstable MeV Majorana tau neutrino can naturally reconcile the cold dark matter model (CDM) with cosmological observations of large and small scale density fluctuations and, simultaneously, with data on solar and atmospheric neutrinos. The solar neutrino deficit is explained through long wavelength, socalled just-so oscillations involving conversions of νe into both ...

Short-lived greenhouse gases that also contribute to air pollution are playing a major role in global warming. Black carbon alone is likely the second or third most important climate forcing agent. The short atmospheric lifetime of these pollutants means that, unlike CO2, reducing emissions produces a decrease in atmospheric concentration and a reduction of the radiative forcing that drives cli...

Atmospheric Chemistry and Physics Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP if available. Abstract Peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) were measured sequentially in situ by an online gas-phase chromatograph with electron capture detector at urba...

Among the halogenated hydrocarbons, chloromethanes (i.e., methyl chloride, CH₃Cl; methylene chloride, CH₂Cl₂; chloroform, CHCl₃; and carbon tetrachloride, CCl₄) play a vital role due to their extensive uses as solvents and chemical intermediates. This article aims to review their main chemical/physical properties and commercial/industrial uses, as well as the environment and health hazards pose...

Coupling of local chemical processes over the globe by atmospheric transport leads to the existence of chemical modes that are a fundamental characterization of global atmospheric chemistry and provide a true description of the atmospheric response to small changes in trace-gas emissions. Such coupled chemistry-transport modes in global tropospheric chemistry are an inherent feature of three-di...

The regional atmospheric chemistry and climate model REMOTE has been used to conduct numerical simulations of the atmosphere during the catastrophic Indonesian fires of 1997. These simulations represent one possible scenario of the event, utilizing the RETRO wildland fire emission database. Emissions from the fires dominate the atmospheric concentrations of O(3), CO, NO(2), and SO(2) creating m...