279 research outputs found
Liquid laser cavities
Liquid laser cavities have plenum chambers at the ends of the capillary cell which are terminated in transparent optical flats. By use of these cavities, several new europium chelates and a terbium chelate can provide laser action in solution at room temperature
Laser action from a terbium beta-ketoenolate at room temperature
Laser activity is achieved in a solution of terbium tris at room temperature in a liquid solvent of acetonitrile or p-dioxane. After precipitation, the microcrystals of hydrated tris chelate are filtered, washed in distilled water, and dried. They show no signs of deterioration after storage
Exploring the multi-humped fission barrier of 238U via sub-barrier photofission
The photofission cross-section of 238U was measured at sub-barrier energies
as a function of the gamma-ray energy using, for the first time, a
monochromatic, high-brilliance, Compton-backscattered gamma-ray beam. The
experiment was performed at the High Intensity gamma-ray Source (HIgS) facility
at beam energies between E=4.7 MeV and 6.0 MeV and with ~3% energy resolution.
Indications of transmission resonances have been observed at gamma-ray beam
energies of E=5.1 MeV and 5.6 MeV with moderate amplitudes. The triple-humped
fission barrier parameters of 238U have been determined by fitting EMPIRE-3.1
nuclear reaction code calculations to the experimental photofission cross
section.Comment: 5 pages, 3 figure
Nuclear photonics at ultra-high counting rates and higher multipole excitations
Next-generation gamma beams beams from laser Compton-backscattering
facilities like ELI-NP (Bucharest)] or MEGa-Ray (Livermore) will drastically
exceed the photon flux presently available at existing facilities, reaching or
even exceeding 10^13 gamma/sec. The beam structure as presently foreseen for
MEGa-Ray and ELI-NP builds upon a structure of macro-pulses (~120 Hz) for the
electron beam, accelerated with X-band technology at 11.5 GHz, resulting in a
micro structure of 87 ps distance between the electron pulses acting as mirrors
for a counterpropagating intense laser. In total each 8.3 ms a gamma pulse
series with a duration of about 100 ns will impinge on the target, resulting in
an instantaneous photon flux of about 10^18 gamma/s, thus introducing major
challenges in view of pile-up. Novel gamma optics will be applied to
monochromatize the gamma beam to ultimately Delta E/E~10^-6. Thus
level-selective spectroscopy of higher multipole excitations will become
accessible with good contrast for the first time. Fast responding gamma
detectors, e.g. based on advanced scintillator technology (e.g. LaBr3(Ce))
allow for measurements with count rates as high as 10^6-10^7 gamma/s without
significant drop of performance. Data handling adapted to the beam conditions
could be performed by fast digitizing electronics, able to sample data traces
during the micro-pulse duration, while the subsequent macro-pulse gap of ca. 8
ms leaves ample time for data readout. A ball of LaBr3 detectors with digital
readout appears to best suited for this novel type of nuclear photonics at
ultra-high counting rates.Comment: 4 pages, 1 figure, 1 tabl
The Prophylactic Use of Bovine Colostrum in a Murine Model of TNBS-Induced Colitis
This study investigated the eects of a short-term administration of bovine colostrum (BC)
in a TNBS model of induced colitis. Colitis was induced by TNBS treatment after seven days of BC (BC
group, n = 12) or saline (control group, n = 12) administration in mice. Clinical signs, histopathological
characteristics, expression levels of Toll-like receptor 4 (TLR4), pro- and anti-inflammatory cytokines,
and microbial composition were assessed. BC was well tolerated and did not induce any histological
damage or clinical symptoms. After TNBS treatment, the BC group showed a reduction in body
weight (BW) loss compared to Control (p < 0.05). Moreover, expression levels of TLR4 (p < 0.01),
Interleukin-1 (IL-1; p < 0.001), Interleukin-8 (IL-8; p < 0.001), and Interleukin-10 (IL-10; p < 0.001)
were lower in mice administered with BC. Finally, Escherichia coli were higher (p < 0.05), while
Enterococci (p < 0.001), Lactobacillus spp. (p < 0.001), and Bifidobacterium spp. (p < 0.05) were lower in
Control than BC group. This study confirms that pre-treatment with BC modulates the expression of
genes and the count of microbes involved in the etiopathogenesis of colitis
In-beam fast-timing measurements in 103,105,107Cd
Fast-timing measurements were performed recently in the region of the
medium-mass 103,105,107Cd isotopes, produced in fusion evaporation reactions.
Emitted gamma-rays were detected by eight HPGe and five LaBr3:Ce detectors
working in coincidence. Results on new and re-evaluated half-lives are
discussed within a systematic of transition rates. The states in
103,105,107Cd are interpreted as arising from a single-particle excitation. The
half-life analysis of the states in 103,105,107Cd shows no change in
the single-particle transition strength as a function of the neutron number
Effects of Goji berries supplementation on the productive performance of rabbit
Abstract
Recognized by the traditional medicine and recent scientific research studies, Lycium barbarum berries (Goji berries) have beneficial effects on human and animal health. The aim of our study was to evaluate the effects of Goji berries on the productive performance of rabbits. One month before insemination, 60 New Zealand White does were randomly assigned to one of the following 3 dietary treatments: commercial standard diet (C); C supplemented with 1% Goji berries (LG); and C supplemented with 3% Goji berries (HG). After weaning up to 91 days of age, 15 randomly selected rabbits/group were fed the same diet as the mothers (C, LG, and HG). Non-pregnant and lactating does of C group showed the highest feed intake (P < 0.01), although no significant differences in body weight (BW) were observed between groups. Nutritional treatment did not affect the offspring's feed intake. However, the rabbits fed with Goji supplementation showed not only higher mean BW both during growth (P < 0.001) and at slaughter (P < 0.01), but also better feed conversion ratio (FCR; P < 0.01) than the control group. Rabbits of LG group showed the best performances in the pre-weaning period which was probably related to the highest milk production of the LG does (P < 0.001). Indeed, LG group showed lower pre-weaning mortality (P < 0.05), higher litter size (P < 0.05), and higher litter weight (P < 0.05) at day 18 as well as higher litter size at weaning (P = 0.05) compared to C group. In conclusion, the present study demonstrates that a low percentage of dietary supplementation with Goji berry improves both reproductive and productive traits of rabbits. Although further studies are needed, our study paves the way for the use of Goji berries in the rabbit nutrition
Search for particle–vibration coupling in 65Cu
The lifetime of the 9/2 + state of 65 Cu, at 2534 keV, has been measured by fast timing techniques, in order to establish wether such state arises from a weak coupling between a p3=2 proton and the 3 octupole vibration at 3.56 MeV in the 64 Ni core. The 65 Cu nucleus was populated by the reaction 7 Li + 64 Ni at 32 MeV, at the Horia Hu- lubei National Institute of Physics and Nuclear Engineering (NIPNE) in Bucharest, and its -decay was detected by the ROSPHERE array. The measured lifetime coresponds to a B(E3) reduced transition probability to the ground state equal to 8.89 W.u., in agreement with theoretical predictions in the weak coupling limit
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