1,353 research outputs found
Tune Determination of Strongly Coupled Betatron Oscillations in a Fast-Ramping Synchrotron
Tune identification - i.e. attribution of the spectral peak to a particular
normal mode of oscillations - can present a significant difficulty in the
presence of strong transverse coupling when the normal mode with a lower
damping rate dominates spectra of Turn-by-Turn oscillations in both planes. The
introduced earlier phased sum algorithm helped to recover the weaker normal
mode signal from the noise, but by itself proved to be insufficient for
automatic peak identification in the case of close phase advance distribution
in both planes. To resolve this difficulty we modified the algorithm by taking
and analyzing Turn-by-Turn data for two different ramps with the beam
oscillation excited in each plane in turn. Comparison of the relative
amplitudes of Fourier components allows for automatic correct tune
identification. The proposed algorithm was implemented in the Fermilab Booster
B38 console application and successfully used in tune, coupling and
chromaticity measurements.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
Momentum Cogging at the Fermilab Booster
The Fermilab booster has an intensity upgrade plan called the Proton
Improvement plan (PIP). The flux throughput goal is 2E17 protons/hour which is
almost double the current operation at 1.1E17 protons/hour. The beam loss in
the machine is going to be an issue. The booster accelerates beam from 400 MeV
to 8GeV and extracts to The Main Injector (MI). Cogging is the process that
synchronizes the extraction kicker gap to the MI by changing radial position of
the beam during the cycle. The gap creation occurs at about 700MeV which is
6msec into the cycle. The variation of the revolution frequency from cycle to
cycle is larger at lower energy and it is hard to control by changing the
radial position because of aperture limitations. Momentum cogging is able to
move the gap creation earlier by using dipole correctors and radial position
feedback, and controlling the revolution frequency and radial position at the
same time. The new cogging is going to save energy loss and aperture. The
progress of the momentum cogging system development is going to be discussed in
this paper.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
Reference Genome Sequence of the Model Plant Setaria
We generated a high-quality reference genome sequence for foxtail millet (Setaria italica). The ~400-Mb assembly covers ~80% of the genome and \u3e95% of the gene space. The assembly was anchored to a 992-locus genetic map and was annotated by comparison with \u3e1.3 million expressed sequence tag reads. We produced more than 580 million RNA-Seq reads to facilitate expression analyses. We also sequenced Setaria viridis, the ancestral wild relative of S. italica, and identified regions of differential single-nucleotide polymorphism density, distribution of transposable elements, small RNA content, chromosomal rearrangement and segregation distortion. The genus Setaria includes natural and cultivated species that demonstrate a wide capacity for adaptation. The genetic basis of this adaptation was investigated by comparing five sequenced grass genomes. We also used the diploid Setaria genome to evaluate the ongoing genome assembly of a related polyploid, switchgrass (Panicum virgatum)
Observation of Instabilities of Coherent Transverse Ocillations in the Fermilab Booster
The Fermilab Booster - built more than 40 years ago - operates well above the
design proton beam intensity of 4x10**12 ppp. Still, the Fermilab neutrino
experiments call for even higher intensity of 5.5x10**12 ppp. A multitude of
intensity related effects must be overcome in order to meet this goal including
suppression of coherent dipole instabilities of transverse oscillations which
manifest themselves as a sudden drop in the beam current. In this report we
present the results of observation of these instabilities at different tune,
coupling and chromaticity settings and discuss possible cures.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
Synthesis and reactivity of some t-butyl-disilanes and -digermanes
Efficient methods of coupling R2EHCl (R = Me, t-Bu; E = Si, Ge) to give R2HEEHR2 have been developed. These dihydrides are readily halogenated with Br2 or I2 to give the corresponding 1,2-dihalo-disilane or -digermane. High yields of Me2ClGeGeClMe2 are obtained by treating hexamethyldigermane with conc. sulfuric acid and ammonium chloride. Conc. sulfuric acid exclusively cleaves methyl groups from [t-BuMe2Ge--]2 to give [t-BuMeClGe--]2 after treatment with ammonium chloride. The latter dichlorodigermane is formed as a mixture of d,l-enantiomers and the meso isomer as shown by NMR evidence. The bulky t-butyl groups render (t-Bu)4Si2Br2 inert to nucleophilic substitution or metal--halogen exchange with organolithium reagents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21820/1/0000221.pd
Antioxidative Properties of Bitter Gourd (Momordica charantia) and Zucchini (Cucurbita pepo)
The enzymatic and non-enzymatic antioxidative capacities of bitter gourd (Momordica charantia) and zucchini (Cucurbita pepo) were investigated in water extracts and chemical buffer extracts. Bitter gourd and zucchini fruits were purchased from a farmer’s market and homogenized separately in water and in a native enzyme extraction buffer. Total phenolic compounds, free radical DPPH scavenging activity, SOD activity and β- glucosidase activity were assayed in the extracts. The average total phenolic compounds recorded in bitter gourd were 13.28 GAE/g fresh weights while in zucchini, the average was 8.67GAE/g fresh weight. This study also found that bitter gourd was 82.05% as effective as ascorbic acid in inhibiting the free radical DPPH while zucchini was 12.19% as effective. The results indicated that bitter gourd was significantly higher in antioxidant content and in β-glucosidase activities than zucchini (P\u3c0.05). On the other hand, significantly higher SOD activities were recorded in zucchini than in bitter gourd extracts
Justifications for the Probation Sanction Among Residents of Virginia--Cool or Un-Cool?
Perhaps as evidence of a growing cultural gap between our students and ourselves, one of the authors was recently amused when a student asked whether probation was a cool sanction. In this study, we begin an investigation into how cool the probation sanction is in the eyes of residents of the Commonwealth of Virginia. Specifically, we use data from a telephone survey of 840 registered voters to explore three questions. First, how often would they recommend the probation sanction in comparison to other sanctions? Second, how do they justify the sanction relative to justifications for other sanctions? Finally, are their justifications and sentencing recommendations consistent across crimes? We address these questions in this study to see whether the sanction is cool or uncool. In the review of literature, we discuss punishment justifications in general and probation as a punitive experience
Composição da comunidade bacteriana do solo sob sistemas integrados na região norte de Mato Grosso.
Os sistemas integrados de produção agrÃcola estão sendo estudados como uma alternativa aos monocultivos tradicionais no intuÃto de tornar a atividade agrÃcola sustentável, particulamente no estado do Mato Grosso. Entretanto, ainda não se conhece como essa atividade afeta as propriedades microbiológicas do solo. Assim, o objetivo deste trabalho foi avaliar e comparar os efeitos de sistemas integrados na composição da comunidade bacteriana do solo com diferentes monocultivos tendo como área referência uma mata nativa do bioma de transição Cerrado e Amazônia. O local de estudo está localizado na Embrapa Agrossilvipastoril no municÃpio de Sinop/MT e foram avaliados sete tratamentos (1-mata nativa, 2-lavoura, 3-pecuária, 4-eucalipto, 5-integração eucalipto lavoura (iEL), 6-integração eucalipto pecuária (iEP), 7-integração eucalipto lavoura pecuária (iELP)) dispostos em quatro blocos casualizados, os quais foram conduzidos segundo as recomendações agronômicas das espécies cultivadas. As amostras de solo foram coletadas nas épocas de chuva e estiagem em 2012 com o auxÃlio de trado holandês na profundidade de 0-10 cm, considerando 20 pontos aleatórios com caminhamento zigue-zague para fazer uma composta de cada tratamento. A extração de DNA total do solo foi realizada com o kit MoBio UltraClean? Soil DNA (MoBio Laboratories, Carlsbad, CA., EUA) conforme protocolo descrito pelo fabricante e sequenciado pela tecnologia Illumina (Illumina, Inc., CA, USA) com a plataforma MiSeq na Universidade da Florida (Gainesville, EUA). Por meio de ferramentas de bioinformática 2.957.127 sequencias do gene 16S rRNA com alta qualidade foram obtidas, sendo que 2.172.432 de OTUs (Operational Taxonomic Units) foram classificados para o domÃnio Bacteria, 3.564 Archaea e 262.994 não foram classificados. A composição bacteriana do solo com abundancia relativa ≥ 10 % a nÃvel de filo apresentou três táxons, porém Firmicutes e Proteobacteria apresentaram padrão de comportamento de maior abundancia na estiagem em relação a chuva para mata nativa e iELP e para a lavoura o padrão foi o oposto . A nÃvel de classe, dentre cinco filos apenas Actinobacteria variou o comportamento para iELP e mata nativa com menor abundância na estiagem e maior na chuva, tendo a lavoura o comportamento inverso e para Clostridia ocorreu o mesmo padrão porém ao contrário para os respectivos tratamentos. Analisando a diferença entre os tratamentos por meio da dissimiliradidade a nÃvel de filo, corte de abundância relativa ≥ 0.05 % (18 filos na estiagem e 21 na chuva), o dendrograma baseado na distância euclidiana agrupou mata nativa e iELP como os mais semelhantes e lavoura o mais dissimilar dentre todos os tratamentos. Podemos concluir, que o sistema integrado eucalipto lavoura pecuária apresentou maior semelhança na sua composição bacteriana do solo com a da mata nativa em comparação com os demais tratamentos avaliados, como também manteve o padrão do comportamento da abundancia relativa parecido na época de estiagem, assim demonstrando indÃcio de sustentabilidade
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