The NEMO-3 experiment measured the half-life of the 2νββ decay and searched for the 0νββ decay of Cd116. Using 410 g of Cd116 installed in the detector with an exposure of 5.26 y, (4968±74) events ...corresponding to the 2νββ decay of Cd116 to the ground state of Sn116 have been observed with a signal to background ratio of about 12. The half-life of the 2νββ decay has been measured to be T1/22ν=2.74±0.04(stat)±0.18(syst)×1019 y. No events have been observed above the expected background while searching for 0νββ decay. The corresponding limit on the half-life is determined to be T1/20ν≥1.0×1023 y at the 90% C.L. which corresponds to an upper limit on the effective Majorana neutrino mass of ⟨mν⟩≤1.4–2.5 eV depending on the nuclear matrix elements considered. Limits on other mechanisms generating 0νββ decay such as the exchange of R-parity violating supersymmetric particles, right-handed currents and majoron emission are also obtained.
A technique of automatic optimization of tuning parameters of the closed-loop automatic control system in the course of operation of the latter is presented. This technique is based on the use of a ...new correlation for calculating tuning parameters of controllers from the coefficients of a transfer function of the object to be controlled. Simple analytical dependences are given that do not require large computer capacities and can easily be incorporated into a microprocessor-based controller, which in this case is converted into a self-tuning device.
The BiPo-3 detector Loaiza, P.; Barabash, A.S.; Basharina-Freshville, A. ...
Applied radiation and isotopes,
05/2017, Letnik:
123
Journal Article
Recenzirano
The BiPo-3 detector is a low radioactive detector dedicated to measuring ultra-low natural contaminations of 208Tl and 214Bi in thin materials, initially developed to measure the radiopurity of the ...double β decay source foils of the SuperNEMO experiment at the μBq/kg level. The BiPo-3 technique consists in installing the foil of interest between two thin ultra-radiopure scintillators coupled to low radioactive photomultipliers. The design and performances of the detector are presented.
In this paper, the final results of the 208Tl and 214Bi activity measurements of the first enriched 82Se foils are reported for the first time, showing the capability of the detector to reach sensitivities in the range of some μBq/kg.
•BiPo3 : low radioactive detector to measure ultra-low levels of 208Tl and 214Bi.•Backgrounds characterized.•Surface background : A(208Tl) =(0.9±0.2)μBq/m2 and A(214Bi) =(1.0±0.3)μBq/m2.•First SuperNemo double β source foils measured : A(208Tl) =(21±11)μBq/kg and A(214Bi) < 290μBq/kg at 90% C.L.•Shows capability to measure 208Tl in the range of some μBq/kg.
The volume 8 of the Catalogue of Palaearctic Coleoptera provides an overview of the bulk of the weevil family Curculionidae and of the family Cryptolaryngidae known to occur in the area covered.
We describe a remarkable and simple alloying procedure in which noble metal intermetallic nanoparticles are produced in gram quantities via digestive ripening. This process involves mixing of ...separately prepared colloids of pure Au and pure Ag or Cu particles and then heating in the presence of an alkanethiol under reflux. The result after 1 h is alloy nanoparticles. Particles synthesized according to this procedure were characterized by UV−vis spectroscopy, EDX analysis, and high-resolution electron microscopy, the results of which confirm the formation of alloy particles. The particles of 5.6 ± 0.5 nm diameter for Au/Ag and 4.8 ± 1.0 nm diameter for Cu/Au undergo facile self-assembly to form 3-D superlattice ordering. It appears that during this digestive ripening process, the organic ligands display an extraordinary chemistry in which atom transfer between atomically pure copper, silver, and gold metal nanoparticles yields monodisperse alloy nanoparticles.
It was brought to my attention by Lee Herman, Jr., American Museum of Natural History, New York, NY, that the following two names in the genus Quedius Stephens are homonyms: 1) Quedius (Microsaurus) ...labradorensis insularis Smetana from North America (Kodiak Island) is a homonym of Quedius insularis Bernhauer and Schubert from New Zealand. I therefore provide a replacement name Quedius labradorensis kodiakensis, new name, for Quedius insularis Smetana (not Quedius insularis Bernhauer and Schubert). 2) Quedius (Raphirus) freyi Smetana from China (Sichuan) is a homonym of Quedius (Raphirus) freyi Scheerpeltz from Cyprus. I therefore provide a replacement name Quedius (Raphirus) freyanus, new name, for Quedius freyi Smetana (not Quedius freyi Scheerpeltz).
In my revision of the New World genera of the tribe Omicrini of the hydrophilid subfamily Sphaeridiinae (1975, Stud. neotr. fauna 10:153-182), I accidentally failed to designate the type species for ...the newly erected genus Aculomicrus . To satisfy Art. 13b of the ICZN Code, and to make the name available, I hereby designate Aculomicrus minimus Smetana 1975 as the type species of Aculomicrus Smetana 1975.
Double beta decay of 100Mo to the excited states of daughter nuclei has been studied using a 600 cm3 low-background HPGe detector and an external source consisting of 2588 g of 97.5% enriched ...metallic 100Mo, which was formerly inside the NEMO-3 detector and used for the NEMO-3 measurements of 100Mo. The half-life for the two-neutrino double beta decay of 100Mo to the excited 01+ state in 100Ru is measured to be T1/2=7.5±0.6(stat)±0.6(syst)⋅1020 yr. For other (0ν+2ν) transitions to the 21+, 22+, 02+, 23+ and 03+ levels in 100Ru, limits are obtained at the level of ∼(0.25–1.1)⋅1022 yr.
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