6,161 research outputs found
Modelling the spring ozone maximum and the interhemispheric asymmetry in the remote marine boundary layer 1. Comparison with surface and ozonesonde measurements
Here we report a modelling study of the spring ozone maximum and its
interhemispheric asymmetry in the remote marine boundary layer (MBL). The
modelled results are examined at the surface and on a series of time-height
cross sections at several locations spread over the Atlantic, the Indian, and
the Pacific Oceans. Comparison of model with surface measurements at remote MBL
stations indicate a close agreement. The most striking feature of the
hemispheric spring ozone maximum in the MBL can be most easily identified at
the NH sites of Westman Island, Bermuda, and Mauna Loa, and at the SH site of
Samoa. Modelled ozone vertical distributions in the troposphere are compared
with ozone profiles. For the Atlantic and the Indian sites, the model generally
produces a hemispheric spring ozone maximum close to those of the measurements.
The model also produces a spring ozone maximum in the northeastern and tropical
north Pacific close to those measurements, and at sites in the NH high
latitudes. The good agreement between model and measurements indicate that the
model can reproduce the proposed mechanisms responsible for producing the
spring ozone maximum in these regions of the MBL, lending confidence in the use
of the model to investigate MBL ozone chemistry (see part 2 and part 3). The
spring ozone maximum in the tropical central south Pacific and eastern
equatorial Pacific are less well reproduced by the model, indicating that both
the transport of precursors from biomass burning emissions taking place
in southeastern Asia, Australia, Oceania, southern Africa, and South America
are not well represented in the model in these regions. Overall, the model
produces a better simulation at sites where the stratosphere and biomass
burning emissions are the major contributors.Comment: 24 pages, 8 figure
Adoptive Cell Therapy for Patients with Melanoma
Adoptive cell therapy can be an effective treatment for some patients with advanced cancer. This report summarizes clinical trial results from the Surgery Branch, NCI, investigating tumor infiltrating lymphocytes (TIL) and gene engineered peripheral blood T cells for the therapy of patients with melanoma and other solid tumors
An Expedited, Regiospecific para-Bromination of Activated Aryls
Electrophilic Aromatic Substitution (EAS) is one of the most frequently used aryl substitution methods. Aside from the fact that most EAS reactions require an acid and an oxidizer to proceed, the reactions involving activated aryls typically produce a mixture of ortho- and para- products as well as an ortho-/para- disubstituted product. Regiospecificity in aromatic substitution is key in the production of many compounds in a variety of disciplines. Since EAS is one of the most often used substitution methods, it is extremely important to develop an efficient method for regiospecific substitutions. Previous research developed a method of ortho-substitution by using hydrocarbon media, a less hazardous, greener medium, which was modified to develop a method of p-iodination (bromination), but with extensive time periods. The research presented here not only reveals an expedient, rapid method for regiospecific p-bromination, but also does so without the need for an acid or an oxidizer. The conditions for p-bromination involve the use of acetone (sometimes with cyclohexane) and NBS resulting in GC yields of p-brominated product approaching 100% in a cost and time efficient manner without the concerns of hazardous materials or byproducts like Br2 or HBr. The reaction mechanism is briefly examined as well
Two teaching units in second-year typewriting
Thesis (M.A.)--Boston University, 1947. This item was digitized by the Internet Archive
Understanding the Clean Air Act: Implementation Issues for Electric Utilities
With the creation of tradable sulfur dioxide permits under the Clean Air Act Amendments of 1990, financial markets have been drawn into the effort to achieve targeted air pollution reductions at least cost. As Susan Dudley explains, financial markets will go well beyond simply providing a place to buy and sell permits. These markets will create a variety of futures contracts that will enable utilities to manage the risks of planning future strategies to control pollution
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