Search results for "Penn"
showing 10 items of 568 documents
The onset of the rainy season and farmers’ sowing strategy for pearl millet cultivation in Southwest Niger
2011
A multi-year (2004-2009) field survey of on-farm sowing practices in 10 villages located in south-west Niger close to Niamey, is analysed to investigate the relationships (i) between rainfall and the sowing date of pearl millet and the risk of sowing failure, (ii) between sowing and meteorological/agro-climatic onset dates, (iii) between sowing/onset dates, and simulated and observed yield/biomass at the end of the season. Even if some villages sow without any synchronous or anterior rainfall, most parcels (73% out of the 1551 available cases) are sown during and just after a 2-day wet spell receiving at least 10 mm. In fact, there is a strong correlation (r = 0.82-0.95 depending on onset d…
Being popular in online social networks: How agentic, communal, and creativity traits relate to judgments of status and liking
2013
We investigated how personality affects both peer-perceived popularity (status) and sociometric popularity (liking) in online social networks (OSNs). Self-ratings of agentic (e.g., extraversion), communal (e.g., agreeableness), and creativity traits (e.g., openness) were collected from 103 OSN profile owners (targets). Unacquainted perceivers provided status and liking judgments based on either targets’ full OSN profiles or profile pictures. Independent coders assessed behavioral cues (e.g., attractiveness) from targets’ OSN profiles. Results showed that targets scoring high on agency were ascribed a high status (without necessarily being liked), whereas targets scoring high on creativity o…
Major International Information Flows Across the Safex Wheat Market
2016
We study information flows across four wheat futures markets on four continents: Zhengzhou Commodity Exchange (ZCE), South African Futures Exchange (SAFEX), Euronext/Liffe and Kansas City Board of Trade (KCBT). Three approaches for studying information flows among non-synchronous markets are applied: cointegration techniques, vector autoregressive analysis and multiple regression proposed. Although comparable underlying assets are traded in the four markets, our results indicate that no long-run links exist among them. ZCE is by far the most endogenous market, and Euronext/Liffe is the most exogenous one. Finally, the model points to KCBT as the most influential and sensitive wheat market. …
Improved comparison of bar P and P charge-to-mass ratios
1995
The measured ratio of charge-to-mass ratios for the antiproton and proton is 1.000 000 001 5 ± 0.000 000 001 1. This 1 part in 109 comparison (1 ppb) is possible because a single or p is now directly observed while trapped in an open access Penning trap. The comparison is the most accurate mass spectrometry of particles with opposite charge and is the most sensitive test of CPT invariance for a baryon system. It is 40 times more accurate than our earlier comparison with many trapped antiprotons and protons, and is more than 45 000 times more accurate than earlier comparisons made with other techniques.
Valores personales en el baloncesto de formación y su relación con el bienestar y la intención futura de práctica a través de la motivación
2019
Tomando como marco teórico la teoría de los valores humanos (Schwartz, 1992; Schwartz et al., 2012), y la teoría de la autodeterminación (Deci y Ryan, 1985, 2000), el objetivo del estudio consistió en poner a prueba un modelo, en una muestra de 115 jugadores jóvenes de baloncesto ( M edad = 13.98, DT = 0.13), en el que se hipotetizó que los diferentes tipos de motivación (motivación autónoma, controlada y no motivación) actuarían como mediadores de la relación entre los va lores informados por los jugadores (auto - trascendencia, conservación, auto - promoción y apertura al cambio) y los indicadores de bienestar (vitalidad subjetiva y afectos positivos), así como con la intención futura de …
Tirdzniecības atvērtības ietekme uz ekonomikas izaugsmi, CAE valstu empīriskais pētījums
2021
Darba mērķis ir izpētīt tirdzniecības atvērtības ietekmi uz ekonomikas izaugsmi, izmantojot 16 Centrālās un Austrumeiropas valstu paneļa datus 2010. – 2019. gadā, salīdzinot 4 dažādus tirdzniecības atvērtības rādītājus. Apvienotie OLS un fiksētie efekti tiek izmantoti kā primārie novērtētāji, un noturības analīzei tiek izmantots sistēmas GMM tests. Apkopoto OLS un fiksēto šķērsgriezumu regresiju iegūtie rezultāti parāda, ka dažādos tirdzniecības atvērtības mērījumos tirdzniecības atvērtība pozitīvi un ļoti nozīmīgi ietekmē ekonomikas izaugsmi. GMM sistēmas testi parāda tirdzniecības atvērtības negatīvo ietekmi uz ekonomikas izaugsmi, bet nozīmīgumu ieguva tikai divi atvērtības rādītāji.
Improved limit on the directly measured antiproton lifetime
2017
Continuous monitoring of a cloud of antiprotons stored in a Penning trap for 405 days enables us to set an improved limit on the directly measured antiproton lifetime. From our measurements we extract a storage time of $3.15\times {10}^{8}$ equivalent antiproton-seconds, resulting in a lower lifetime limit of ${\tau }_{\bar{{\rm{p}}}}\gt 10.2\,{\rm{a}}$ with a confidence level of $68 \% $. This result improves the limit on charge-parity-time violation in antiproton decays based on direct observation by a factor of 7.
Cadmium mass measurements between the neutron shell closures at N=50 and 82
2010
International audience; The mass values of the neutron-deficient cadmium isotopes 99−109Cd and of the neutronrich isotopes 114,120,122−124,126,128Cd have been measured using ISOLTRAP. The behavior of the separation energies of the cadmium isotopes from N = 50 to 82 is discussed.
The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results
2007
The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for differ…
Theory of simultaneous dipole and quadrupole excitation of the ion motion in a Penning trap
2012
Abstract Penning traps confine ions of atoms and molecules as well as other charged particles by a combination of static electric and magnetic fields to the central region of the trap, where these objects can be studied. Most experiments employ pulses of dipolar radio-frequency radiation followed by pulses of quadrupolar radio-frequency radiation to manipulate the motional state of the trapped particles. Instead of a sequential procedure an excitation of the ion motion by the simultaneous application of dipolar and quadrupolar rf-fields is also conceivable. This paper investigates the theory of simultaneous excitation under very general assumptions, with inclusion of possible damping terms.…