Search results for "spektrit"

Electron spectra in forbidden β decays and the quenching of the weak axial-vector coupling constant gA

2017

Evolution of the electron spectra with the effective value of the weak axial-vector coupling constant ${g}_{\mathrm{A}}$ was followed for 26 first-, second-, third-, fourth- and fifth-forbidden ${\ensuremath{\beta}}^{\ensuremath{-}}$ decays of odd-$A$ nuclei by calculating the involved nuclear matrix elements (NMEs) in the framework of the microscopic quasiparticle-phonon model (MQPM). The next-to-leading-order terms were included in the $\ensuremath{\beta}$-decay shape factor of the electron spectra. The spectrum shapes of third- and fourth-forbidden nonunique decays were found to depend strongly on the value of ${g}_{\mathrm{A}}$, while first- and second-forbidden decays were mostly unaff…

Advanced voice and data solutions for evolution of cellular network system

2014

Spectrum and energy efficient solutions for OFDMA collaborative wireless networks

2013

Hyperspektrisen kaukokartoitusdatan analysointialgoritmeja

2003

FTIR matrix isolation and theoretical studies of glycolic acid dimers

2018

Glycolic acid (GA) dimers were studied in low temperature argon matrices by means of FTIR spectroscopy. Experimentally, the dimers were produced when monomeric glycolic acid molecules were thermally mobilized upon annealing of argon matrices at 25–35 K. The experimental spectra observed upon annealing indicate the presence of three different dimer structures. Computationally, MP2 and DFT calculations were used to study the potential dimer species in order to scrutinize the possible dimer structures, their energetics and their spectral features. Altogether 27 local minima were found for dimer structures for the three lowest conformers of glycolic acid considered based on previous studies on …

Solar UV radiation and plant responses : assessing the methodological problems in research concerning stratospheric ozone depletion

2010

LIISA-ionilähteen vetyplasman VUV-spektrin ja H ̄ -ionisuihkun intensiteetin korrelaatio

2016

Tässä työssä tutkitaan negatiivisen vetyionilähteen plasman tuottaman ultraviolettisäteilyn ja ionilähteen tuottaman negatiivisen vetyionisuihkun intensiteetin välistä korrelaatiota. Työssä löydettiin korrelaatio VUV-spektrin tiettyjen aallonpituusalueiden intensiteettien välisen suhteen ja Faraday-kupilla mitatun suihkuintensiteetin välillä. Korrelaatio ei kuitenkaan ole yksiselitteinen ja pätee ainoastaan rajoitetussa painealueessa. Vetyplasman molekylaarisen emission Lyman-vyön spektrin ja suihkun korrelaation tarkastelusta huomattiin, että elektronisen perustilan vibronisten viritystilojen 10 ja 11 tuoton suhde korkeampien viritystilojen tuottoon on olennainen negatiivisten vetyionien t…

Electron spectra in forbidden β decays and the quenching of the weak axial-vector coupling constant gA

2017

Evolution of the electron spectra with the effective value of the weak axial-vector coupling constant gA was followed for 26 first-, second-, third-, fourth- and fifth-forbidden β− decays of odd-A nuclei by calculating the involved nuclear matrix elements (NMEs) in the framework of the microscopic quasiparticle-phonon model (MQPM). The next-to-leading-order terms were included in the β-decay shape factor of the electron spectra. The spectrum shapes of third- and fourth-forbidden nonunique decays were found to depend strongly on the value of gA, while first- and second-forbidden decays were mostly unaffected by the tuning of gA. The gA-driven evolution of the normalized β spectra was found t…

¹²C-ionien energiajättö vedessä

2015

Tässä tutkimuksessa käsiteltiin varatuista raskaista hiukkasista koostuvan säteilyn yleistä käyttäytymistä sen vuorovaikuttaessa materiaalin kanssa, sekä tutustuttiin lyhyesti erilaisiin tapoihin mitata säteilyn energiajättöä. Lisäksi MCP-pohjaisiin lentoaikailmaisimiin perustuvalla mittausasetelmalla määritettiin kokeellisesti C-12-ioneista koostuvan säteilyn energiajättöä eripaksuisissa vesikohtioissa. Kohtioiden paksuudet olivat 0,39 mm, 0,57 mm ja 0,93 mm. Motivaationa mittauksille toimi suihkujen käyttö hadroniterapiassa, sillä varattujen raskaiden hiukkasten energiajätön käyttäytyminen materiassa toimii syvällä kudoksissa olevien kasvainten hoitoon erityisen hyvin. Lopulliset tulokset…

gA-driven shapes of electron spectra of forbidden β decays in the nuclear shell model

2017

The evolution of the shape of the electron spectra of 16 forbidden β− decays as a function of gA was studied using the nuclear shell model in appropriate single-particle model spaces with established, well-tested nuclear Hamiltonians. The β spectra of 94Nb(6+)→94Mo(4+) and 98Tc(6+)→98Ru(4+) were found to depend strongly on gA, which makes them excellent candidates for the determination of the effective value of gA with the spectrum-shape method (SSM). A strong gA dependence is also seen in the spectrum of 96Zr(0+)→96Nb(6+). This decay could be used for determining the quenching of gA in sixth-forbidden decays in the future, when the measurement of the spectrum becomes experimentally feasibl…