Search results for "heavy [meson]"
showing 10 items of 385 documents
Search for heavy neutrinos with the T2K near detector ND280
2019
This paper reports on the search for heavy neutrinos with masses in the range 140<MN<493 MeV/c2 using the off-axis near detector ND280 of the T2K experiment. These particles can be produced from kaon decays in the standard neutrino beam and then subsequently decay in ND280. The decay modes under consideration are N→ℓ±απ∓ and N→ℓ+αℓ−β(−)ν(α,β=e,μ). A search for such events has been made using the Time Projection Chambers of ND280, where the background has been reduced to less than two events in the current dataset in all channels. No excess has been observed in the signal region. A combined Bayesian statistical approach has been applied to extract upper limits on the mixing elements of heav…
Utilisation des minéraux lourds comme indicateurs de paléoplacers alluvionnaires diamantifères en République centrafricaine (RCA). Use of heavy miner…
2001
International audience; Le diamant est la première ressource minérale de la République Centrafricaine (RCA). Exclusivement exploité par plusieurs sociétés minières avant 1960, il l'est maintenant de façon artisanale. Avec une production annuelle d'envi-ron 500 000 carats (1 carat = 0,2 g), la RCA est le dixième producteur de diamant (en valeur) dans le monde. Les diamants gemmes (pierres de joaillerie, taillables) représentent 70 à 75 % de la production. Deux principales zones diamantifères présentant une relation spatiale évidente existent en RCA : la Formation de Mouka-Ouadda à l'Est et celle de Carnot à l'Ouest. Ces formations, représentant les 'roches magasins' du diamant, constituent a…
A Noxious Weed Ambrosia artemisiifolia L. (Ragweed) as Sustainable Feedstock for Methane Production and Metals Immobilization
2023
Plants of the Ambrosia genus are invasive and cause many ecological problems, including the oppression of the growth of agricultural crops and native plants, land depletion, and the production of strong allergens. The use of weeds as a sustainable feedstock for biogas production, either methane or hydrogen, is a promising way to fulfill the energy needs of the current generation, eliminate the depletion of non-renewable carbon resources, and preserve the ecosystem degradation caused by invasive species impacts. A diversified microbial community was used as inoculum and Ambrosia artemisiifolia L. biomass as a substrate for anaerobic degradation and methane production. In this regard, the dev…
Elemental contamination of an open-pit mining area in the Peruvian Andes
2014
New technologies and higher prices of raw materials have promoted the expansion of mining activity throughout the world; if not properly regulated, this activity can lead to contamination of the local and regional environ- ment. The city of Cerro de Pasco is located close to a large open-pit mine and in recent years, several reports have pro- vided evidence of environmental contamination and related health problems. The aim of this paper is to evaluate the contamination in fluvial water, sediments and biological fluids from this area. The collective results show elevated metal and metalloid concentrations in rivers and sediments, especially in the areas downstream of the mine. For instance,…
ELECTROCHEMICAL METHODS DETERMINATION OF HEAVY METALS IN WINE BEVERAGE ACHIEVING ECOSANOGENE
2014
In this work, we estimated reproducibility and procedures to improve the selectivity of the method and to determine the influence of different analytical parameters (pH, electrolyte composition, deposition time and potential, presence of ligands). Detection limit of copper in samples of white wine and red Blaj (Romania) is 2.4 ppm, with a deviation of 1.5-2,0%. The results were compared with the results by atomic adsorption classical method. The sensitivity of the method is two times smaller, Daton this Pb2- ions.
Structure of superheavy nuclei along decay chains of element 115
2014
[Introduction] A recent high-resolution α , X -ray, and γ -ray coincidence-spectroscopy experiment offered the first glimpse of excitation schemes of isotopes along α -decay chains of Z = 115. To understand these observations and to make predictions about shell structure of superheavy nuclei below 288 115, we employ two complementary mean-field models: the self-consistent Skyrme energy density functional approach and the macroscopic-microscopic Nilsson model. We discuss the spectroscopic information carried by the new data. In particular, candidates for the experimentally observed E 1 transitions in 276 Mt are proposed. We find that the presence and nature of low-energy E 1 transitions in w…
Effetti trasversi nella propagazione di fasci ottici in vetri ad alto indice
2008
We investigate beam propagation in a novel Heavy Metal Oxide glass, reporting near infrared beam self-confinement and solitons, filamentation, interactions and conical emission at picoseconds and discussing them with the aid of a model.
The Assessment of Heavy Metal Contamination of the Cultivated Soils in the Odra River Floodplain
2021
Abstract The aim of the study was to assess the contamination of selected heavy metals in cultivated soils of the Odra river floodplain. The heavy metals Mn, Fe, Cu, Zn, Ni, Cd and Pb were determined in soil samples collected in the autumn of 2020 - after the vegetation period of plants from designated measurement points. Concentrations of the analytes were measured using an atomic absorption spectrometer (F-ASA). A comparison was made between concentrations of heavy metals in soil samples collected from areas flooded in 1997 and from areas flooded as a result of rainfall, snowmelt and winter floods. The results of the studies were compared with the data for soils taken from non-flooded are…
117番元素Ts合成のための48Ca+249Bk融合反応
2019
We have performed an experiment to synthesize the element 117 (Ts) with the $^{48}$Ca+$^{249}$Bk fusion reaction. Four $\alpha$-decay chains attributed to the element 117 were observed. Two of them were long decay chains which can be assigned to the one originating from the $\alpha$ decay of $^{294}$Ts. The other two were short decay chains which are consistent with the one originating from the $\alpha$ decay of $^{293}$Ts. We have compared the present results with the literature data, and found that our present results mostly confirmed the literature data, leading to the firm confirmation of the synthesis of the element 117.
Use of algae in active biomonitoring of Surface waters
2014
Przeprowadzono badania biomonitoringowe trzech zbiorników retencyjnych położonych na terenie województwa opolskiego (południowa Polska): Zbiornika Turawa, Zbiornika Nysa i Zbiornika Otmuchów. W glonach słodkowodnych Spirogyra sp. i morskich Palmaria palmata (Linnaeus) Weber & Mohr, eksponowanych w badanych wodach, oznaczono metodą absorpcyjnej spektrometrii atomowej (AAS) przyrosty stężeń: Mn, Fe, Cu, Zn, Cd i Pb. W wodach oznaczano także pH, konduktywność oraz stężenie Mn i Fe. Stężenia Cu, Zn, Cd i Pb w badanych wodach były mniejsze od granicy oznaczalności metody. Badania prowadzono od czerwca do lipca 2014 r. Wskazano na różnice w przyrostach stężeń metali ciężkich w próbkach glonów eks…