20 research outputs found
The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources
The production and analysis of distributed sources of 24Na and 222Rn in the
Sudbury Neutrino Observatory (SNO) are described. These unique sources provided
accurate calibrations of the response to neutrons, produced through
photodisintegration of the deuterons in the heavy water target, and to low
energy betas and gammas. The application of these sources in determining the
neutron detection efficiency and response of the 3He proportional counter
array, and the characteristics of background Cherenkov light from trace amounts
of natural radioactivity is described.Comment: 24 pages, 13 figure
Parity Violation in Proton-Proton Scattering
Measurements of parity-violating longitudinal analyzing powers (normalized
asymmetries) in polarized proton-proton scattering provide a unique window on
the interplay between the weak and strong interactions between and within
hadrons. Several new proton-proton parity violation experiments are presently
either being performed or are being prepared for execution in the near future:
at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at
230 MeV and near 1.3 GeV. These experiments are intended to provide stringent
constraints on the set of six effective weak meson-nucleon coupling constants,
which characterize the weak interaction between hadrons in the energy domain
where meson exchange models provide an appropriate description. The 221 MeV is
unique in that it selects a single transition amplitude (3P2-1D2) and
consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The
TRIUMF 221 MeV proton-proton parity violation experiment is described in some
detail. A preliminary result for the longitudinal analyzing power is Az = (1.1
+/-0.4 +/-0.4) x 10^-7. Further proton-proton parity violation experiments are
commented on. The anomaly at 6 GeV/c requires that a new multi-GeV
proton-proton parity violation experiment be performed.Comment: 13 Pages LaTeX, 5 PostScript figures, uses espcrc1.sty. Invited talk
at QULEN97, International Conference on Quark Lepton Nuclear Physics --
Nonperturbative QCD Hadron Physics & Electroweak Nuclear Processes --, Osaka,
Japan May 20--23, 199
Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set
This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of 3He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active 8B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54-0.31+0.33(stat.)-0.34+0.36(syst.)×106 cm-2 s-1, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Δm2=7.59-0.21+0.19×10 -5eV2 and θ=34.4-1.2+1.3degrees
Desempenho reprodutivo, concentrações de progesterona e metabólitos lipídicos no pós-parto de vacas mestiças H/Z, submetidas a uma dieta hiperlipidêmica Reproductive performance, concentrations of progesterone and lipidic metabolites in the postpartum crossbred dairy cows submitted to a hyperlipidemic diet
Para avaliar o efeito de uma dieta hiperlipidêmica nos níveis séricos de metabólitos lipídicos e progesterona e no desempenho reprodutivo, 42 vacas mestiças foram submetidas a dois tratamentos: T1 (n=21) dieta-controle e T2 (n=21) dieta hiperlipidêmica, tendo como principal fonte de lipídios o grão de soja integral. Os intervalos médios para a primeira e segunda ovulações pós-parto foram 26,3 e 35,9 dias para os animais do T1 e 21,7 e 37,4 dias para os do T2. Os intervalos médios do parto ao início da atividade luteal, primeiro estro e primeiro ciclo estral normal foram, respectivamente, 29,9; 39,5; e 53,9 dias para T1 e 25,7; 33,3; e 52,3 dias para T2. A duração média do primeiro ciclo estral foi de 14,7 e 16,9 dias e do segundo de 19,8 e 19,5 dias para T1 e T2, respectivamente. As concentrações de progesterona nos ciclos estrais normais ocorridos durante o período de 90 dias pós-parto variaram de valores mínimos de 0,27 (T1) e 0,31 ng/mL (T2), nos dias 0 e 1 (dia 0 = ovulação), para valores máximos de 6,71 ng/mL (T1), nos dias 10 e 11, e 7,04 ng/mL (T2), nos dias -9 e --8, retornando a níveis basais (<1 ng/mL) nos dias -3 e -2. As concentrações médias de colesterol total e colesterol HDL para T1 e T2 foram, respectivamente, 100,74 e 67,3 mg/dL e 162,25 e 95,8 mg/dL. O efeito de hipercolesterolemia da dieta foi confirmado nesta pesquisa, mas sem nenhum aumento nas concentrações de progesterona e desempenho reprodutivo.<br>To evaluate the effect of a hiperlipidemic diet on the reproductive performance, lipidic metabolites and serum progesterone levels, 42 Holstein-Zebu crossbred cows were submitted to two treatments: T1 (n=21), control diet, and T2 (n=21), hyperlipidemic diet, consisting mainly on whole soybean. The mean intervals to the first and second postpartum ovulations were 26.3 and 35.9 days for animals of T1 and 21.7 and 37.4 days for those of T2. The average intervals from calving to onset of the luteal activity, first estrus and first normal estrus cycle length were respectively, 29.9, 39.5, and 53.9 days for T1 and 25.7, 33.3, and 52.3 days for T2. The average first estrus cycle was 14.7 and 16.9 days and of the second 19.8 and 19.5 days for T1 and T2, respectively. The concentrations of serum progesterone in the normal estrus cycles during the period of 90 days postpartum, varied from minimum values of 0.27 ng/mL (T1) to 0.31 ng/mL (T2) on the days 1 and 0 (day 0 = ovulation) to maximum values of 6.71 ng/mL (T1) on days 10 and 11 and 7.04 ng/mL (T2) on days -9 and --8, returning to basal levels (<1 ng/mL) on days -3 e -2. The total cholesterol and HDL average concentrations for T1 e T2 were 100.74 and 67.3 mg/dL (T1) and 162.25 and 95.8 mg/dL (T2) respectively. The hypercholesterolemic effect of the diet was confirmed, but without any increase in the concentration of progesterone and reproductive performance
ON BECOMING MORE OF A POLICY SCIENTIST
This essay presents some subjective thoughts on becoming more of a policy scientist, based on nearly thirty years of intense interest in policymaking and its improvement. Written as a token of gratitude for the privilege of receiving the first Harold Lasswell Award from the Policy Studies Organization, the essay takes the form of advice to striving policy scientists in nine desiderata followed by five operational recommendations. Some readings for exploring the suggestions presented in this paper are included in the reference section. Copyright 1984 by The Policy Studies Organization.