Search results for "heavy [meson]"
showing 10 items of 385 documents
Finite amplitude method applied to giant dipole resonance in heavy rare-earth nuclei
2015
Background: The quasiparticle random phase approximation (QRPA), within the framework of the nuclear density functional theory (DFT), has been a standard tool to access the collective excitations of the atomic nuclei. Recently, finite amplitude method (FAM) has been developed, in order to perform the QRPA calculations efficiently without any truncation on the two-quasiparticle model space. Purpose: We discuss the nuclear giant dipole resonance (GDR) in heavy rare-earth isotopes, for which the conventional matrix diagonalization of the QRPA is numerically demanding. A role of the Thomas-Reiche-Kuhn (TRK) sum rule enhancement factor, connected to the isovector effective mass, is also investig…
Investigation of the reaction 64Ni+238U being an option of synthesizing element 120
2010
This study is concerned with the search for entrance channels suitable to synthesize elements with Z > 118. Mass-energy distributions as well as capture cross-sections of fission-like fragments have been measured for the reactions 64Ni + 238U → 302120 and 48Ca + 238U → 286112 at energies near the Coulomb barrier. Compound nucleus fission cross-sections were estimated from the analysis of mass and total kinetic energy distributions. The cross-section drops three orders of magnitude for the formation of the compound nucleus with Z = 120 obtained in the reaction 64Ni + 238U compared to the formation of the compound nucleus with Z = 112 obtained in the reaction 48Ca + 238U at an excitation ener…
Exploring the stability of super heavy elements: First Measurement of the Fission Barrier of $^{254} $No
2013
The gamma-ray multiplicity and total energy emitted by the heavy nucleus 254No have been measured at 2 different beam energies. From these measurements, the initial distributions of spin I and excitation energy E * of 254No were constructed. The distributions display a saturation in excitation energy, which allows a direct determination of the fission barrier. 254No is the heaviest shell-stabilized nucleus with a measured fission barrier. © Owned by the authors, published by EDP Sciences, 2014.
Long-lived particles at the energy frontier: the MATHUSLA physics case
2019
We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of Standard Model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the $\mu$m scale up to the Big Bang Nucleosynthesis limit of $\sim 10^7$m. Neutral LLPs with lifetimes above $\sim$ 100m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging …
Biomonitoring of Atmospheric Aerosol with the use of Apis mellifera and Pleurozium schreberi
2019
The aim of the carried out research was to assess atmospheric aerosol pollution levels in the area of three apiaries located in the Opole Province and to analyse heavy metals pollution in bee honey and western honey bees. Pleurozium schreberi moss was used in analysing atmospheric aerosol pollution with the active biomonitoring method, whereas heavy metals levels were determined with flame atomic absorption spectrometry method (F-AAS). Relative Accumulation Factors (RAF) were used in determining increases of analytes concentrations in the moss samples. As a result of the carried out study, the following conclusions have been reached: mosses are good bioindicators of environment pollution th…
Mosses as biomonitor of air pollution with analytes originating from tobacco smoke
2018
The aim of the carried out research was the assessment of the possibility to use a popular bioindicator - Pleurozium schreberi mosses as a biosensor of the air pollution in living quarters with the analytes originating from tobacco smoke. The moss bag method of active biomonitoring, popular in environmental studies, was applied; the method is based on exposing mosses collected in clean areas in the locations polluted with, for example, heavy metals. However, this experiment involved exposing mosses in living quarters, in which approximately 10 cigarettes were smoked daily (first room - kitchen). For the purpose of comparison, moss samples were also placed in another room (bedroom), which wa…
The influence of environmental conditions on the lifespan of mosses under long-term active biomonitoring
2021
Abstract Biomonitoring with living organisms is most often used in order to gather quick information about environmental quality – for example the level of heavy metals polluting the air. Experiments are not often performed when the bioindicator is exposed to pollutants over the long time (6 months and more) because this period required to obtain credible results and the risk not yet studied of physiological changes and of degeneration of the living material which would undoubtedly affect the biomonitoring results. The aim of study was to evaluate the physiological condition of Pleurozium schreberi moss species subjected to continuous exposure for a year, using the moss-bag method, under va…
Geographical and ecological outline of metal(loid) accumulating plants in Italian vascular flora
2018
The decontamination of heavy metal polluted soils is one of the major challenges that our industrialized world has to face. Remediation technologies are being developed and employed in order to reduce the potential hazards of metal and metalloid contamination. Plants capable of uptaking metals and metalloids in their tissues can be an effective tool to remove such pollutants from contaminated soils. The use of this plant-driven process (Phytoremediation) requires the knowledge of the right phytoextractors to use when facing different types of contamination. The aim of this paper is to provide an inventory of phytoextractors that can be used in Phytoremediation procedures in Italy. The check…
Leaf Biosorbents for the Removal of Heavy Metals
2018
The presence of heavy metals in waters is a global concern. Among various remediation technologies, biosorption is an attractive and promising process since in many cases, it is fast, selective, and highly efficient. Other advantages, such as applicability for various types of pollutants, simplicity, low cost, ease of operation, and the potential reusability of the adsorbents, make it beneficial. Nowadays, more and more green materials, raw or modified, are inclined to be explored instead of conventional adsorbents, within concept of Green Chemistry. This review focuses on the use of leaves-based biosorbents in raw or modified forms to sequestrate heavy metals from waters and wastewaters.
Recent advances on portable sensing and biosensing assays applied for detection of main chemical and biological pollutant agents in water samples: A …
2021
Abstract The quality analysis of water, pharmaceutical and environmental compounds is a basic subject for human health. The presence of low-quality drugs, biological toxins and chemical compounds in water or forbidden additives in the nourishments lead to irreversible problems in human health. Hence, multiple analytical approaches have been presented for investigating the quality of environmental, pharmaceutical, and food compounds and monitoring the detection of toxic compounds and pollutants in water. Sensing tools based on analytical strategies are required for identifying and quantifying the different pollutants including biological and chemical contaminants in water samples. Among diff…