7 research outputs found
Radiocezij u mahovinama u Parku prirode KopaÄki rit u Hrvatskoj: traganje za neprijavljenim ispuÅ”tanjem iz nuklearnih postrojenja u ratom razorenoj Ukrajini
The invasion of Ukraine and military operations around Ukrainian nuclear power plants and other nuclear facilities have prompted us to search for radiocaesium in mosses from the KopaÄki Rit Nature Park in Croatia, since mosses are known bioindicators of airborne radioactive pollution, and KopaÄki Rit is a known low radiocaesium background area. Sampling was finished in August 2023, and our analysis found no elevated radiocaesium levels. KopaÄki Rit therefore remains a suitable place for future detection of anthropogenic radioactive pollutants.Invazija na Ukrajinu i vojne operacije oko ukrajinskih nuklearnih elektrana i drugih nuklearnih postrojenja potaknule su nas da potražimo radiocezij u mahovinama u Parku prirode KopaÄki rit, jer su mahovine poznati bioindikatori radioaktivnog oneÄiÅ”Äenja zraka, a KopaÄki je rit poznat po niskoj razini oneÄiÅ”Äenja radiocezijem. Uzorkovanje je zavrÅ”eno u kolovozu 2023. NaÅ”a analiza nije otkrila poviÅ”ene razine radiocezija. KopaÄki rit stoga ostaje pogodno mjesto za buduÄu detekciju antropogenog radioaktivnog oneÄiÅ”Äenja
Multichannel Anomaly of the Resonance Pole Parameters Resolved
Inspired by anomalies which the standard scattering matrix pole-extraction
procedures have produced in a mathematically well defined coupled-channel
model, we have developed a new method based solely on the assumption of
partial-wave analyticity. The new method is simple and applicable not only to
theoretical predictions but to the empirical partial-wave data as well. Since
the standard pole-extraction procedures turn out to be the lowest-order term of
the proposed method the anomalies are understood and resolved.Comment: 5 page
The detailed mechanism of the eta production in pp scattering up to the Tlab = 4.5 GeV
Contrary to very early beliefs, the experimental cross section data for the
eta production in proton-proton scattering are well described if pi and only
eta meson exchange diagrams are used to calculate the Born term. The inclusion
of initial and final state interactions is done in the factorization
approximation by using the inverse square of the Jost function. The two body
Jost functions are obtained from the S matrices in the low energy effective
range approximation. The danger of double counting in the p-eta final state
interaction is discussed. It is shown that higher partial waves in
meson-nucleon amplitudes do not contribute significantly bellow excess energy
of Q=100 MeV. Known difficulties of reducing the multi resonance model to a
single resonance one are illustrated.Comment: 10 pages, 5 figures, corrected typos in relation (3), changed content
(added section with differential cross sections
Wi-Fi i ljudsko zdravlje
An enormous increase in the application of wireless communication in recent decades has intensified research into consequent increase in human exposure to electromagnetic (EM) radiofrequency (RF) radiation fields and potential health effects, especially in school children and teenagers, and this paper gives a snap overview of current findings and recommendations of international expert bodies, with the emphasis on exposure from Wi-Fi technology indoor devices. Our analysis includes over 100 in vitro, animal, epidemiological, and exposure assessment studies (of which 37 in vivo and 30 covering Wi-Fi technologies). Only a small portion of published research papers refers to the ārealā health impact of Wi-Fi technologies on children, because they are simply not available. Results from animal studies are rarely fully transferable to humans. As highly controlled laboratory exposure experiments do not reflect real physical interaction between RF radiation fields with biological tissue, dosimetry methods, protocols, and instrumentation need constant improvement. Several studies repeatedly confirmed thermal effect of RF field interaction with human tissue, but non-thermal effects remain dubious and unconfirmed.ZnaÄajan porast uporabe bežiÄne RF komunikacije u posljednjim desetljeÄima te s tim povezane izloženosti ljudi umjetno stvorenom neionizirajuÄem zraÄenju (RF polja), koje prije nije postojalo na Zemlji, tema su velikog broja istraživanja moguÄih utjecaja tih zraÄenja na okoliÅ” i zdravlje ljudi, osobito djece i mladih, kako bi se utvrdile Äinjenice o meÄudjelovanju RF polja s genskim materijalom živih biÄa. U ovom radu dan je pregled aktualnih istraživanja i preporuka meÄunarodnih struÄnih tijela. Poseban naglasak dan je na moguÄi utjecaj radiofrekvencijskoga zraÄenja na mlade odnosno na Å”kolsku djecu koja su mu tijekom Å”kolovanja svakodnevno dodatno izložena tijekom e-Å”kole koriÅ”tenjem najmodernijih Wi-Fi tehnologijskih rjeÅ”enja za komunikaciju u obrazovanju
Fundamental properties of resonances
All resonances, from hydrogen nuclei excited by the high-energy gamma rays in deep space to newly discovered particles produced in Large Hadron Collider, should be described by the same fundamental physical quantities. However, two distinct sets of properties are used to describe resonances: the pole parameters (complex pole position and residue) and the Breit- Wigner parameters (mass, width, and branching fractions). There is an ongoing decades-old debate on which one of them should be abandoned. In this study of nucleon resonances appearing in the elastic pion-nucleon scattering we discover an intricate interplay of the parameters from both sets, and realize that neither set is completely independent or fundamental on its own