Sudesna mjerenja γγ-raspada stanja 166Ho nastalih reakcijom (n,γ)

Levels of 166Ho were studied using thermal and average resonance neutron capture and with the (d,p) and (d,3He) reactions. We have devoted a large effort to the measurements of the γγ-coincidence spectra in the broad energy region 50 - 6243 keV. Based on these data and those of earlier studies, the levels are grouped into 23 rotational bands. Among them are 6 new ones. The results are in good agreement with the semiempirical and quasiparticle-phonon model, where Coriolis and residual interactions are taken into account. Details of model interpretation have been presented in a previously published paper.Proučavali smo stanja 166Ho nastala termičkim i prosječnim rezonantnim uhvatom neutrona, te (d,p) i (d,3He) reakcijama. Uložili smo velik trud u mjerenjima sudesnih γγ-spektara u širokom energijskom području od 50 do 6243 keV. Na osnovi tih i ranijih podataka, stanja su grupirana u 23 rotacijske vrpce. Među njima je i 6 novih. Ishodi su u suglasju s poluempiričkim i kvazičestično-fononskim modelom, uzimajući u obzir Coriolisovo međudjelovanje i rezidualne interakcije. Podrobnosti modelskog tumačenja objavljene u u ranijem članku

Sudesna mjerenja γγ-raspada stanja 166Ho nastalih reakcijom (n,γ)

Levels of 166Ho were studied using thermal and average resonance neutron capture and with the (d,p) and (d,3He) reactions. We have devoted a large effort to the measurements of the γγ-coincidence spectra in the broad energy region 50 - 6243 keV. Based on these data and those of earlier studies, the levels are grouped into 23 rotational bands. Among them are 6 new ones. The results are in good agreement with the semiempirical and quasiparticle-phonon model, where Coriolis and residual interactions are taken into account. Details of model interpretation have been presented in a previously published paper.Proučavali smo stanja 166Ho nastala termičkim i prosječnim rezonantnim uhvatom neutrona, te (d,p) i (d,3He) reakcijama. Uložili smo velik trud u mjerenjima sudesnih γγ-spektara u širokom energijskom području od 50 do 6243 keV. Na osnovi tih i ranijih podataka, stanja su grupirana u 23 rotacijske vrpce. Među njima je i 6 novih. Ishodi su u suglasju s poluempiričkim i kvazičestično-fononskim modelom, uzimajući u obzir Coriolisovo međudjelovanje i rezidualne interakcije. Podrobnosti modelskog tumačenja objavljene u u ranijem članku

Study of ^194 Ir via thermal neutron capture and (d,p) reactions

Levels of ^194 Ir were studied using thermal neutron capture reaction. A pair spectrometer was used to measure the high-energy gamma-ray spectrum from thermal-neutron capture in enriched ^193 Ir target over the energy range 4640 - 6100 keV. The low-energy gamma-radiation from the reaction was studied with crystal diffraction spectrometers, and conversion electrons were observed with magnetic spectrometers. The high-sensitivity measurements at the Grenoble reactor, evaluated for transition energies up to 500 keV, are compared with lower-sensitivity measurements at the Wuerenlingen and Salaspils reactors. The comparison helped to obtain reliable isotopic identification for a number of ^194 Ir lines. The multipolarity admixtures for 29 gamma-transitions were determined on the basis of conversion lines from different electron subshells. Prompt and delayed gamma-gamma coincidences were measured using semiconductor and scintillation detectors. The ^193 Ir(d,p) high-resolution spectra, observed with a magnetic spectrometer, are given. All these data contributed to establishing a detailed level scheme of ^194 Ir. Additional data and the interpretation of the results in terms of current models will be presented in a forthcoming paper

Proučavanje 194Ir uhvatom termičkih neutrona I (d, p) reakcijom

Levels of 194Ir were studied using thermal neutron capture reaction. A pair spectrometer was used to measure the high-energy γ-ray spectrum from thermal-neutron capture in enriched 193Ir target over the energy range 4640 - 6100 keV. The low-energy γ-radiation from the reaction was studied with crystal diffraction spectrometers, and conversion electrons were observed with magnetic spectrometers. The high-sensitivity measurements at the Grenoble reactor, evaluated for transition energies up to 500 keV, are compared with lower-sensitivity measurements at the Wuerenlingen and Salaspils reactors. The comparison helped to obtain reliable isotopic identification for a number of 194Ir lines. The multipolarity admixtures for 29 γ-transitions were determined on the basis of conversion lines from different electron subshells. Prompt and delayed γ-γ coincidences were measured using semiconductor and scintillation detectors. The 193Ir(d,p) high-resolution spectra, observed with a magnetic spectrometer, are given. All these data contributed to establishing a detailed level scheme of 194Ir. Additional data and the interpretation of the results in terms of current models will be presented in a forthcoming paper.Proučavala su se stanja u 194Ir reakcijama 193Ir(n, γ) i 193Ir(d, p). Mjerenja uhvata termičkih neutrona načinjena su uz reaktore u Grenoblu, Wuerenlingenu i Salapsisu. Za mjerenja γ-zračenja visoke energije upotrebljavao se spektrometar parova, a za niske energije difraktometar. Konverzijske elektrone se mjerilo magnetskim spektrometrom. Mjerenja reakcije (d, p) visokog razlučivanja izvedena su magnetskim spektrometrom. Usporedbe tih mjerenja omogućile su pouzdano izotopno prepoznavanje prijelaza u 194 Ir, a spektri konverzijskih elektrona i određivanje multipolnosti prijelaza. Dobiveni su podaci osnova sheme raspada 194Ir

Proučavanje 194Ir uhvatom termičkih neutrona I (d, p) reakcijom

Levels of 194Ir were studied using thermal neutron capture reaction. A pair spectrometer was used to measure the high-energy γ-ray spectrum from thermal-neutron capture in enriched 193Ir target over the energy range 4640 - 6100 keV. The low-energy γ-radiation from the reaction was studied with crystal diffraction spectrometers, and conversion electrons were observed with magnetic spectrometers. The high-sensitivity measurements at the Grenoble reactor, evaluated for transition energies up to 500 keV, are compared with lower-sensitivity measurements at the Wuerenlingen and Salaspils reactors. The comparison helped to obtain reliable isotopic identification for a number of 194Ir lines. The multipolarity admixtures for 29 γ-transitions were determined on the basis of conversion lines from different electron subshells. Prompt and delayed γ-γ coincidences were measured using semiconductor and scintillation detectors. The 193Ir(d,p) high-resolution spectra, observed with a magnetic spectrometer, are given. All these data contributed to establishing a detailed level scheme of 194Ir. Additional data and the interpretation of the results in terms of current models will be presented in a forthcoming paper.Proučavala su se stanja u 194Ir reakcijama 193Ir(n, γ) i 193Ir(d, p). Mjerenja uhvata termičkih neutrona načinjena su uz reaktore u Grenoblu, Wuerenlingenu i Salapsisu. Za mjerenja γ-zračenja visoke energije upotrebljavao se spektrometar parova, a za niske energije difraktometar. Konverzijske elektrone se mjerilo magnetskim spektrometrom. Mjerenja reakcije (d, p) visokog razlučivanja izvedena su magnetskim spektrometrom. Usporedbe tih mjerenja omogućile su pouzdano izotopno prepoznavanje prijelaza u 194 Ir, a spektri konverzijskih elektrona i određivanje multipolnosti prijelaza. Dobiveni su podaci osnova sheme raspada 194Ir

Study of ^194 Ir via thermal neutron capture and (d,p) reactions

Levels of ^194 Ir were studied using thermal neutron capture reaction. A pair spectrometer was used to measure the high-energy gamma-ray spectrum from thermal-neutron capture in enriched ^193 Ir target over the energy range 4640 - 6100 keV. The low-energy gamma-radiation from the reaction was studied with crystal diffraction spectrometers, and conversion electrons were observed with magnetic spectrometers. The high-sensitivity measurements at the Grenoble reactor, evaluated for transition energies up to 500 keV, are compared with lower-sensitivity measurements at the Wuerenlingen and Salaspils reactors. The comparison helped to obtain reliable isotopic identification for a number of ^194 Ir lines. The multipolarity admixtures for 29 gamma-transitions were determined on the basis of conversion lines from different electron subshells. Prompt and delayed gamma-gamma coincidences were measured using semiconductor and scintillation detectors. The ^193 Ir(d,p) high-resolution spectra, observed with a magnetic spectrometer, are given. All these data contributed to establishing a detailed level scheme of ^194 Ir. Additional data and the interpretation of the results in terms of current models will be presented in a forthcoming paper

Phosphine Modulation for Enhanced CO₂ Capture: Quantum Mechanics Predictions of New Materials

It is imperative to develop efficient CO2 capture and activation technologies to combat the rising levels of deleterious greenhouse gases in the atmosphere. Using Quantum Mechanics methods (Density Functional Theory), we propose and evaluate several metal-free and metal-containing phosphines that provide strong CO2 binding under ambient conditions. Depending on the electron donating capacity of the phosphine and the ability of the P-bound ligands to hydrogen bond to the CO2, we find that the CO2 binding can be as strong as −18.6 kcal/mol downhill, which should be quite adequate for ambient conditions. We explore some modifications of the phosphine to improve CO2 binding, and we elucidate which chemical descriptors correlate directly with CO2 binding energy. Specifically, we find that charge accumulation on the CO2 unit of the CO2-bound adduct has the greatest correlation with CO2 binding affinity. Finally, we probe the mechanism for CO2 reduction to CO and methanol in aqueous media

Phosphine Modulation for Enhanced CO₂ Capture: Quantum Mechanics Predictions of New Materials

It is imperative to develop efficient CO2 capture and activation technologies to combat the rising levels of deleterious greenhouse gases in the atmosphere. Using Quantum Mechanics methods (Density Functional Theory), we propose and evaluate several metal-free and metal-containing phosphines that provide strong CO2 binding under ambient conditions. Depending on the electron donating capacity of the phosphine and the ability of the P-bound ligands to hydrogen bond to the CO2, we find that the CO2 binding can be as strong as −18.6 kcal/mol downhill, which should be quite adequate for ambient conditions. We explore some modifications of the phosphine to improve CO2 binding, and we elucidate which chemical descriptors correlate directly with CO2 binding energy. Specifically, we find that charge accumulation on the CO2 unit of the CO2-bound adduct has the greatest correlation with CO2 binding affinity. Finally, we probe the mechanism for CO2 reduction to CO and methanol in aqueous media