α-Bromoketals and acetals are important synthetic precursors in organic synthesis. In this work, some new α-bromoketals are synthesized by the reaction of aryl methyl ketones with diols in the presence of 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU) hydrobromide-perbromide in good isolated yields. The latter compound converts aldehydes to acetals and serves as a new and efficient reagent for t...

[1] Airborne measurements in regions of varying meteo‐ rology and pollution are used to quantify the contribution of organic acids and a mass spectral marker for oxygenated aerosols, m/z 44, to the total organic aerosol budget. Organic acids and m/z 44 separately are shown to exhibit their highest organic mass fractions in the vicinity of clouds. The contribution of such oxygenated species is s...

Here, we report a facile strategy for the synthesis of cadmium and cobalt metal-organic frameworks (MOFs), their subsequent conversion to corresponding oxide. Thus, Cd-MOF Co-MOF were prepared by successive ionic layer adsorption reaction (SILAR) using Cd 2+ or Co cation precursors p -phenylenediamine (PPD) anion precursor. As-synthesized particles with unique morphology converted into CdO 3 O ...

a simple method has been employed to synthesize copper and copper oxide nanoparticles from copper (ii) succinate precursor by thermal decomposition method using oleylamine as a capping agent. the particles synthesized with oleylamine and triphenylphosphine were well dispersed nanoparticles obtained from x-ray diffraction (xrd). the synthesized copper nanoparticles were characterized by uv-visib...

a two-week tunnel study was conducted in monterrey, mexico during june 2009 to characterizevolatile organic compound (voc) emissions from the local vehicle fleet and estimate the correspondingemission factors (efs). the loma larga tunnel (llt), a 532 meter-long structure that is mainly used by lightduty gasoline-powered vehicles was used as the experimental set-up. ambient air samples (2-hour a...

2016 © American Water Works Association JOURNAL AWWA OCTOBER 2016 | 108:10 Microfiltration (MF) membranes are low-pressure membranes that generally have pore sizes in the range of 1 to 0.1 μm. They can effectively reject bacteria, protozoa, and colloidal particles by size exclusion. The physical rejection of viruses and the dissolved fraction of natural organic matter (NOM) by MF (0.1 μm nomina...

In 1935 Anson crystallized carboxypeptidase from autolyzed beef pancreas glands (2) and reported that fresh pancreas did not contain the active enzyme, but an inactive precursor, procarboxypeptidase. The precursor was partially purified and found to be activated by trypsin (3). In contrast to the pancreatic enzymes trypsin and chymotrypsin, which are prepared directly from their purified precur...

Described here is a new and highly general strategy for multiple-template (multitemplate) patterning. This process is significant because it allows us to create various unusual shapes such as solid spheres, yolk-shell spheres, flowerlike particles, and structured nanocomponents. Alcoholysis of the metal-organic precursors with mixtures of glycerol and various amounts of ethanol followed by calc...

[1] Inclusion of isoprene as a source of secondary organic aerosol (SOA) in a global model increases the global burden of SOA from all sources by more than a factor of two. The isoprene source substantially increases SOA concentrations in the free troposphere, because isoprene, and, more importantly, isoprene’s oxidation products, have much greater concentrations at higher altitudes than other ...

Complexes and clusters bridge the gap between molecular and macroscopic levels by linking individual gaseous molecules to newly formed nanoparticles but the driving forces and mechanism for the formation of complexes and clusters in the atmosphere are not well understood. We have performed ab initio and density functional quantum chemical calculations to elucidate the role of organic acids in t...