A calculated risk

When Boston's Jeremiah E. Burke High School lost its accreditation in 1995, no one expected that the path to improvement would lead to the school's first-ever AP Calculus class.Education - Massachusetts - Boston

Third Interger Resonance Slow Extraction Using RFKO at High Space Charge

A proposal to search for direct {\mu}-->e conversion at Fermilab requires slow, resonant extraction of an intense proton beam. Large space charge forces will present challenges, partly due to the substantial betatron tune spread. The main challenges will be maintaining a uniform spill profile and moderate losses at the septum. We propose to use "radio frequency knockout" (RFKO) for fine tuning the extraction. Strategies for the use of the RFKO method will be discussed here in the context of the Mu2e experiment. The feasibility of this method has been demonstrated in simulations.Comment: 3 pp. 2nd International Particle Accelerator Conference: IPAC 2011. 4-9 Sep 2011. San Sebastian, Spai

Including the Interactive White Board in a Classroom

In the last decade, a new technology has started to make its way into countless classrooms around the world. This technology is the Interactive White Board (IWB) system. This self study project shows ways a teacher can integrate the IWB technology in an elementary school classroom. This study was conducted in a first grade classroom in an urban area through analyzing lessons, student work, and teacher journals. The lessons that were taught all included the use of an IWB in different ways, including viewing of online sources, accessing curriculum materials, providing interactive materials, documenting student or teacher work, modeling, and creating opportunities for students to be active learners. I found that the IWB is an effective tool in both delivery of materials during lessons and assessment

Machado de Assis leitor dos românticos brasileiros

O artigo busca reler os textos críticos em que Machado de Assis contempla alguns dos autores românticos brasileiros, de forma a averiguar a sua assimilação dos procedimentos textuais do movimento que marcou o nascimento de nossa identidade literária. Por outro lado, o trabalho busca surpreender, nesses textos, a formação e o estabelecimento de um olhar sobre o romantismo brasileiro – olhar que se perpetua em nossa crítica literária atual.The present text reads the critical essays that M. de Assis wrote about some of the Brazilian romantic authors, in order to recognize his apprehension of the textual proceedings of this movement, which distinguishes the birth of the Brazilian literary identity. On the other side, the article tries to expose, in Machado’s critique, the development and the establishment of a theory of Brazilian Romanticism – a theory that perpetuates itself until today in our literary criticism

O Romantismo brasileiro lido por Antonio Candido

O artigo retoma um texto bastante conhecido de Antonio Candido, “A educação pela noite”, para tentar apontar o que há ali de crítica que funda paradigmas de leitura, ao mesmo tempo em que limita a compreensão do Romantismo brasileiro e reafirma a sua tão propalada inadequação e/ou acriticidade. Ou seja, na leitura feita da prosa de Álvares de Azevedo, é patente a dificuldade de atribuir uma autonomia crítica a nosso Romantismo, apesar do artigo ser, sem dúvida, a maior virada interpretativa na leitura da obra azevediana até o momento

Synthesis, Structure, and Reactivity ofbis(1,2,4-tri-t-butylcyclopentadienyl) Complexes of Cerium

The sterically demanding 1,2,4-tri-t-butylcyclopentadienylligand (1,2,4-(Me3C)3C5H2, hereafter Cp') has been used to preparemonomeric cerium metallocenes, Cp 2CeX (X = Cl, I, OSO2CF3), which areused to synthesize the benzyl, Cp'2CeCH2C6H5. The benzyl is a usefulstarting material for preparing other complexes in the Cp'2CeZ system (Z= BF4, F, NH2, C6H5, H). X-ray crystal structures of Cp'2CeOSO2CF3,Cp'2CeF, Cp'2CeCH2C6H5, and Cp'2CeH are presented. The benzyl slowlydecomposes in solution to toluene and a metallacycle,[Cp'][(Me3C)2C5H2(CMe2CH2)]Ce. The ring CMe3 groups of both themetallacycle and the hydride, Cp'2CeH, can be fully deuterated byprolonged exposure to C6D6, providing a useful labeling tool inmechanistic studies.The hydride activates C-F and/or C-H bonds influorobenzenes, C6HxF6-x , x = 0-5. The reactions are selective, with theselectivity depending on the presence of two fluorines ortho to thereaction site more than on the type of bond activated. Complexes of thetype Cp'2CeC6HxF5-x , x = 0-4, are formed as intermediates, which slowlydecompose in solution to Cp'2CeF and fluorobenzynes, C6HxF4-x, x = 0-4,which are trapped. The rate at which Cp'2CeC6HxF5-x complexes decomposeincreases as the number of fluorines decreases. Complexes with oneortho-fluorine decompose much faster than those with two ortho-fluorines.The metallacycle activates only C-H bonds in fluorobenzenes, permittingthe synthesis of specific Cp'2CeC6HxF5-x complexes. The crystal structureof Cp'2CeC6F5 is presented. The hydride and the metallacycle react withfluoromethanes, CH4-xFx, x = 1-3, through postulated Cp'2CeCH3-xFxintermediates to generate Cp'2CeF and other products. The other products,CH4, tri-t-butylbenzenes, tri-t-butylfluorobenzenes, and a presumedmetallocene cerium fluoride with one Cp' and one (Me2EtC)(Me3C)2C5H2ligand, suggest a decomposition pathway for Cp'2CeCH3-xFx , x = 1-3, thatinvolves carbenes or carbenoids, which are trapped. The hydridepolymerizes ethylene, but hydrogenates other olefins. The metallacycleactivates C-H bonds in olefins and aromatics to generate new complexeswith Ce-C bonds. The hydride reacts with one equivalent of CO in pentaneto generate (Cp'2Ce)2CH2O, whose crystal structure shows the presence ofa bridging dianionic formaldehyde ligand. (Cp'2Ce)2CH2O reacts H2 to givethe hydride and Cp'2CeOMe, or with a mixture of H2 and CO to generateCp'2CeOMe exclusively. (Cp'2Ce)2CH2O or the hydride can react with anadditional equivalent of CO to generate dimeric enediolate,(Cp'2CeCHO)2