A fast ultrasound-assisted sequential extraction (UASE) procedure for the determination of cadmium, lead and nickel fractions in soil was developed and fully validated. The working parameters of an ultrasound probe were optimized by comparing the content of metals in soil extracts obtained by the UASE procedure with that obtained by the conventional (with the aid of a vertical rotor) modified C...

Explicitly correlated local coupled-cluster (LCCSD-F12) methods with pair natural orbitals (PNOs), orbital specific virtual orbitals (OSVs), and projected atomic orbitals (PAOs) are compared. In all cases pair-specific virtual subspaces (domains) are used, and the convergence of the correlation energy as a function of the domain sizes is studied. Furthermore, the performance of the methods for ...

Metal (Cr, Co, Cu, Zn, Cd, Pb, Ni) and metalloid (As) accumulation was studied in roadside soil and wild rat (Rattus sp.) samples from near a Pb-Zn mine (Kabwe, Zambia) and the capital city of Zambia (Lusaka). The concentrations of the seven metals and As in the soil samples and Pb in the rat tissue samples were quantified using atomic absorption spectroscopy. The concentrations of Pb, Zn, Cu, ...

BACKGROUND A new blood lead testing instrument has qualities that make the instrument attractive for on-site testing of occupational lead exposures. This study evaluated the accuracy of the instrument when used in a manufacturing setting, and examined the impact of blood storage and shipment on results. METHODS Venous blood specimens (n=121) were obtained and immediately analyzed on-site usin...

We investigate the applicability of two-line atomic fluorescence (TLAF) from seeded indium atoms for temperature measurements in highly sooting flames. The results show that TLAF holds promise for two-dimensional temperature measurements in sooting and fuel-rich flames under conditions in which other thermometry techniques fail, a result that is attributed to the superior characteristics of the...

A new fast method for determination of mobile zinc fractions in soil is proposed in this work. The three-stage modified BCR procedure used for fractionation of zinc in soil was accelerated by using ultrasounds. The working parameters of an ultrasound probe, a power and a time of sonication, were optimized in order to acquire the content of analyte in soil extracts obtained by ultrasound-assiste...

This paper describes the findings of selenium measurement in three types of soil (semigley, pseudogley and hypogley) and in wheat grain cultivated in these types of soil in the vicinity of Koprivnica using hydrid atomic absorption spectrometry. The results showed relatively low selenium levels in all three types of soil (145-333 micrograms Se/kg dry weight) as well as the wheat grain (22-62 mic...

The nonlinear absorption (NLA) properties of free base and metalated porphyrins with a unique 5,10-A(2)B(2) substitution pattern were studied with open Z-scan technique at 532 nm in the nanosecond regime over a broad range of input fluence. The NLA responses were found to be dependent on structural features and the solvent used. In most cases, the character of the response differed from that ty...

We explore phenomenologies of the topflavour model for the LEP experiment at m Z scale and the atomic parity violation (APV) experiment in the Cs atoms at low energies. Implications of the model on the Z peak data are studied in terms of the precision variables ǫ i 's. We find that the LEP data give more stringent constraints on the model parameters than the APV data.

The quantitative analysis of molecular density matrices in terms of oriented quasi-atomic orbitals (QUAOs) is shown to yield detailed conceptual insight into the dissociation of dioxetane on the basis of ab initio wave functions. The QUAOs persist and can be followed throughout the reaction path. The kinetic bond orders and the orbital populations of the QUAOs quantitatively reveal the changes ...