Giant dipole resonance in55Mn* studied with the BGO detector

High-energy gamma-rays emitted in the decay of the giant dipole resonance built on excited states of⁵⁵Mn nucleus were measured with a bismuth germanate detector. Resonance parameters were extracted from the fits to the experimental spectra. Two new high-energy calibration points originating from slow-neutron capture in germanium isotopes of bismuth germanate crystal are proposed for large-volume BGO detectors.     

Yrast excitations in129Te

Using an 11.4MeV/u¹³⁶Xe beam of the UNILAC accelerator of GSI and a^natW target, A=184 isobars were produced and separated by using an on-line mass separator. A new isomeric state was found in¹⁸⁴Hf. This state decays with a half-life of 48(10) s and emits three -rays of 73, 482, and 555 keV as well as lower-lying cascade transitions. The hindrance of the 73 keV-E1 transition with K=8 is compared with those of other even-even hafnium isotopes. The half-life of¹⁸⁴Lu was estimated to be between 15 and 25s.     

Surface modifications of upgraded high-speed tool steel

The SW7M high-speed tool steel of composition Fe (80%), Mo (5%), Cr (4%), V (2%) and C (1%) was studied by conversion electron Mössbauer spectroscopy at 293 K. The specimen consists mainly of -Fe, martensite and austenite grains. The unwanted fraction of austenite was reduced by polishing the sample in an external magnetic field. At elevated temperatures, the SW7M steel exhibits a selective oxidation of its fraction. The corrosion rate is sigificantly reduced by N and Ti low-energy ion bombardment.     

Analytical considerations on the use of a fruit-specific and representative matrix in pesticide residue analysis by LC-ESI-MS/MS

One of the quantification methods frequently applied to pesticide residue analysis in food by liquid chromatography — mass spectrometry (LC-MS) involves matrix-matched calibrations with a representative matrix used for all commodities belonging to one group. This approach, although very practical, is deemed to generate analytical errors. The effect of the application of a representative-matrix calibration curve on the pesticide quantification result was examined. Extractions of 56 pesticides from five soft fruits (strawberries, blackberries, raspberries, black currant and red currant) were carried out using QuEChERS method. Pesticide determinations were performed by LC-MS/MS in multiple reaction monitoring mode. Quantification difference functions and parameters were proposed and calculated. At the concentration of 0.05 mg kg^?1 for ca. 90% of examined pesticides the quantification difference arising from the use of a representative matrix calibration curve (raspberries) instead of a specific fruit matrix calibration curve was below 20% for black and red currents, and below 30% and 35% in the case of strawberries and blackberries, respectively. The 25% difference limit was not exceeded for 51 pesticides in black and red currents, 46 pesticides in blackberries and 45 pesticides in strawberries. Quantification difference functions and parameters such as relative standard deviation of corrected process efficiencies were found to be helpful in data-driven decision-making on the applicability of a representative matrix; the former may be also used as a tool for data correction to ensure the reliability and accuracy of analyses.      

Hard-to-reach nuclei studied with deep-inelastic heavy-ion reactions

Spectroscopic studies performed with deep-inelastic heavy-ion reactions are reviewed for two regions of neutron-rich nuclei. The identification of isomers in nearly complete series of Sn isotopes and the resulting systematic of B(E2) values for isomeric transitions is presented and followed by the discussion of shell model states studied in neutron-rich Te isotopes including the new four neutron-hole isomers identified in ¹³⁰Te. Yrast spectroscopy studies of nuclei from the doubly magic ²⁰⁸Pb region are described by outlining the highest spin states observed in the ²⁰⁸Pb core nucleus. The E3 transitions observed abundantly in yrast decays are discussed within the framework of particle-octupole vibration coupling and the validity of a simple rule connecting energy shifts of octupole states built on one-particle states with the ones observed for two-particle states is demonstrated.Received: 15 January 2003, Published online: 23 March 2004PACS: 21.60.Cs Shell model - 23.20.Lv transitions and level energies - 27.60. + j - 27.80. + w      

Discrete γ-rays in the reactions of 143 MeV32S with58Ni

The reactions induced by 143 MeV³²S on⁵⁸Ni have been studied detecting discrete γ-rays in coincidence with projectile-like fragments (PLF). Information on PLF excitation probability and sequential decay of target-like fragments (TLF) has been obtained. For the²⁸Si+⁶²Zn outgoing channel at small energy loss (¦Q¦<20 MeV), both PLF and TLF data indicate that thermal equilibrium is not attained. The hypothesis of an equal excitation energy partition between the two reaction fragments does not describe properly experimental TLF data. A dependence of PLF excitation probability on the outgoing channel is found for the two final channels³²S+⁵⁸Ni and²⁸Si+⁶²Zn. The values of the spin alignment parameterP _zz, derived for PLF and TLF from measurements ofγ-rays anisotropy, are in disagreement with the expectations of the transport theory for dissipative collisions.     

Transition probabilites betweenvh 11 2/n states in Sn isotopes

A simple evaporation and percolation model is applied to calculate the amount of excitation energy needed to have multifragmentation.     

Projectile-like fragments excitation and gamma-rays emission after the deep inelastic reaction of32S on58Ni

The deep-inelastic reaction induced by 143 MeV³²S on⁵⁸Ni have been studied detecting projectile-like fragments (PLF) in coincidence withγ-rays in NaI(TI) scintillators. γ-ray multiplicity and anisotropy have been derived for Z_plf=14, 15 as a function of energy loss and/or γ-energy. The information obtained are compared with a discrete γ-line study of the same reaction. The effect of the exit channel selection (ejectileZ, energy loss,E _γ) on the γ-observables is discussed in connection with the evidence of a strong PLF γ-emission.     

Estimation of free copper ion concentrations in blood serum using T(1) relaxation rates

The water proton relaxation rate constant R(1)=1/T(1) (at 60 MHz) of blood serum is substantially increased by the presence of free Cu2+ ions at concentrations above normal physiological levels. Addition of chelating agents to serum containing paramagnetic Cu2+ nulls this effect. This was demonstrated by looking at the effect of adding a chelating agent-D-penicillamine (D-PEN) to CuSO4 and CuCl2 aqueous solutions as well as to rabbit blood serum. We propose that the measurement of water proton spin-lattice relaxation rate constants before and after chelation may be used as an alternative approach for monitoring the presence of free copper ions in blood serum. This method may be used in the diagnosis of some diseases (leukaemia, liver diseases and particularly Wilson's disease) because, in contrast to conventional methods like spectrophotometry which records the total number of both bound and free ions, the proton relaxation technique is sensitive solely to free paramagnetic ions dissolved in blood serum. The change in R(1) upon chelation was found to be less than 0.06 s(-1) for serum from healthy subjects but greater than 0.06 s(-1) for serum from untreated Wilson's patients.