4 resultados para Bertrand Bergeron

em Bucknell University Digital Commons - Pensilvania - USA


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Based on the Ricker/Witmer survey on Library Support for Science Research and Education, a brief statistical analysis of the Bucknell University community and library support for science and engineering research and education is provided. The position and responsibilities of Reference Librarian/Coordinator of Science and Engineering Resources in the Ellen Clarke Bertrand Library are detailed. Throughout the article, I describe the motivation and justification for an integrated university library collection, which serves not only the Science and Engineering faculty and students, but the entire Bucknell University community. The issues of finance and budget, public service, and information access and delivery in relation to a central university library are discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In an effort to reduce Interlibrary borrowing activity, while enhancing the Library collection, the Bertrand Library has initiated a program to purchase current monographs requested through ILL by Bucknell University students and faculty. The results have been a successful reduction in ILL workload, and a cost-effective means of document delivery as measured by average delivery time, cost-per-title, processing costs, and circulation statistics. This procedure reflects an overall change in our philosophy concerning document access and delivery, which led to the reorganization of ILL services and staff in the Bertrand Library.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The atom efficient phospha-Michael reaction between bis 4-methylphenyl phosphine oxide and several activated internal alkenes has been shown to occur under microwave irradiation without added solvent or catalyst. The alkenes used for this study were ethyl 4-nitrocinnamate, two chalcones ((E)-3-(4-methoxy-phenyl)-1-(4- nitrophenyl)-prop-2-en-1-one and (E)-1-(4-methoxyphenyl)-3-(3-nitro-phenyl)-prop-2- en-1-one), and 2-phenylmethylene-propanedinitrile. In the case of ethyl 4-nitrocinnamate, reaction with bis 4-methylphenyl phosphine oxide for sixty minutes at 130 °C yielded the desired phospha-Michael product in a 55% yield after purification. Varying the location of the nitro group on the phenyl rings of the chalcones did not seem to have a large effect on their reactivity. By NMR, both chalcones seemed to react to the same extent when the reaction times and temperatures were held constant. Interestingly, a phospha-Michael reaction was observed at a reaction temperature of 65°C for experiments involving 2- phenyl-methylene-propanedinitrile while the other substrates required a reaction temperature of 130 °C. Similar experiments were carried out with bis mesityl phosphine oxide and two internal alkenes: 2-phenylmethylene-propanedinitrile and ethyl-2-cyano-3- methyl-2-butenoate. These experiments did not yield any of the predicted phospha- Michael products, which suggest steric limitations to the Michael donor for this reaction.