Octavian Duliu - Academia.edu (original) (raw)

Papers by Octavian Duliu

Experimental Methods in the Physical Sciences

Abstract Electron paramagnetic resonance (EPR) spectroscopy as an analytical method in the proven... more Abstract Electron paramagnetic resonance (EPR) spectroscopy as an analytical method in the provenance studies of carbonates, proposed for the first time in 1983 by Cordischi et al. (1983) has become in the past decades a reliable technique, especially when used in the case of marble artifacts. The main descriptor in this investigation was showed to be the Mn2+ spectrum, which consists of a hyperfine structure sextet as well as one or more singlets between the third and the forth sextet lines. In spite of an apparent simplicity, the Mn2+ spectrum of nonirradiated and irradiated carbonates, i.e., calcite and dolomite as well as the corresponding types of marbles or travertine, displays a multitude of characteristics that could be better described by means of the spin Hamiltonian (SH) parameters, where values could be relatively easy determined by an appropriate computer simulation. Different SH parameters such as resonance line half width, fine structure zero field splitting, and g-factors as well as the sixths line shape together with multivariate statistical analysis method such as principal component, factor, or discriminant analysis could be successfully used to discriminate between limestones or marbles coming from different quarries.

Agronomy

Teucrium L. is a widely distributed genus often used for the treatment of digestive disorders and... more Teucrium L. is a widely distributed genus often used for the treatment of digestive disorders and respiratory problems. The aim of the present study was to determine the chemical composition of essential oils and elemental content of the plant species Teucrium polium, Teucrium hircanicum, Teucrium botrys, Teucrium chamaedrys, Teucrium flavum, Teucrium orientale, and Teucrium scordium of Moldovan origin, as well as to evaluate the antimicrobial activity of their extracts. The composition of essential oils was determined using gas chromatography–mass spectrometry (GC–MS), and neutron activation analysis (NAA) was used to assess the elemental composition of plants. Antimicrobial tests were performed in vitro on the Bacillus subtilis, Pseudomonas fluorescens, Xanthomonas campestris, Erwinia amylovora, Erwinia carotovora, and Candida utilis strains using the double-dilution method. GC–MS allowed the identification of 59 components of the analyzed essential oils, and showed that the analy...

Spectroscopic Techniques for Archaeological and Cultural Heritage Research, 2020

Environmental Science and Pollution Research, 2021

Characterization and monitoring of the air quality in terms of pollution and toxicity impact.  T... more Characterization and monitoring of the air quality in terms of pollution and toxicity impact.  The concentrations of 35 and 40 elements were determined using two analytical methods.  Instrumental neutron activation analysis and atomic absorption spectrometer.  The enrichment factor, pollution load index, potential ecological risk, risk index, and human and ecotoxicity were assessed.

$Research paper thumbnail of The structure of scleractinian coral skeleton analyzed by neutron diffraction and neutron computed tomography$

Scientific Reports, 2020

Two analytical methods based on the neutrons high penetrability, i.e. neutron diffraction (ND) an... more Two analytical methods based on the neutrons high penetrability, i.e. neutron diffraction (ND) and neutron computed tomography (NCT) were used to investigate the structure of the aragonitic skeleton of an exemplar/sample of Dipastraea pallida (Dana 1846), a modern hermatypic coral. ND was used to reconstruct the orientation distribution function (ODF) of the crystalline fibrils which compose the coral skeleton. Accordingly, 684 ND spectra were analyzed using the Rietveld method. The result confirmed the aragonite as the sole mineral component of coral skeleton, allowing to recalculate the ODF of aragonite fibrils and to represent it by means of (100), (010) and (001) crystallographic planes pole figures (PF). Experimental PF showed a remarkable similarity with PF recalculated by considering that all aragonite fibrils are oriented either along the growth axis of polyp cups or perpendicular to this direction. This result confirmed the previous observations based on optical microscopy,...

Radiation, 2021

For a better understanding of the previously observed increased natural radioactivity at the conf... more For a better understanding of the previously observed increased natural radioactivity at the confluence of the Varzob and Sioma rivers, Central Tajikistan, the activity concentration of natural radioactive 40K, Th and U daughters as well as of the anthropogenic 137Cs were determined in nine locations covering the entire Sioma River. The radiometric determinations evidenced, in addition to increased activity concentrations of Th and U daughter radionuclides, an anomalous accumulation of anthropic 137Cs and natural 210Pb in the middle of the Sioma gorge. Complementarily, the mass fractions of natural Th and U determined by instrumental neutron activation analysis evidenced an increased presence of Th and U, which, in some places, overpasses six-times the average mass fraction found in the upper continental crust. The possible influence of active air transport from the southern Tadjik plane during the Afghani storms, as well as the presence of actinide-rich minerals, were analyzed and ...

Plants, 2021

The producers of essential oils from the Republic of Moldova care about the quality of their prod... more The producers of essential oils from the Republic of Moldova care about the quality of their products and at the same time, try to capitalize on the waste from processing. The purpose of the present study was to analyze the chemical composition of lavender (Lavanda angustifolia L.) essential oil and some by-products derived from its production (residual water, residual herbs), as well as to assess their “in vitro” antimicrobial activity. The gas chromatography-mass spectrometry analysis of essential oils produced by seven industrial manufacturers led to the identification of 41 constituents that meant 96.80–99.79% of the total. The main constituents are monoterpenes (84.08–92.55%), followed by sesquiterpenes (3.30–13.45%), and some aliphatic compounds (1.42–3.90%). The high-performance liquid chromatography analysis allowed the quantification of known triterpenes, ursolic, and oleanolic acids, in freshly dried lavender plants and in the residual by-products after hydrodistillation o...

Geological Society, London, Special Publications, 2020

To investigate the influence of local climate and transboundary circulation of moisture on the st... more To investigate the influence of local climate and transboundary circulation of moisture on the stable isotope of precipitation in Ramnicu Valcea, Romania, monthly values of δ2H, δ18O, deuterium excess (dexcess), temperature, relative humidity and precipitation were determined between January 2012 and December 2018. Monthly analysis showed differences in dexcess varying between 24.2‰ (October 2015) and −23.7‰ (July 2013) with a multi-annual average of 6.1 ± 5.9‰, suggesting an Atlantic origin of moisture with episodic Mediterranean transport. Also a significant correlation between the North Atlantic Oscillation on the local temperature during winter season was noticed. The local meteoric water line (LMWL) for the entire period showed slope and intercept values similar to those for neighbouring localities with the same altitude. When the analysis was extended to summer (April–October) and winter (November–March) seasons, the LMWL slope and intercept were different, reflecting the summ...

Microchemical Journal, 2020

The aims of present study consist of collecting more information on the geochemistry of the Varzo... more The aims of present study consist of collecting more information on the geochemistry of the Varzob river unconsolidated sediments as reflecting the diversity of the South-Hissar range together with a comprehensive evaluation of the anthropogenic contamination of the same sediments.

Proceedings of European Physical Society Europhysics Conference on High Energy Physics — PoS(EPS-HEP 2009), 2010

Data in Brief, 2019

This data is the first comprehensive baseline data on the geochemical composition of soil and sed... more This data is the first comprehensive baseline data on the geochemical composition of soil and sediments along the Nile River and Delta in Egypt that was subjected and analyzed by instrumental neutron activation analysis INAA. These data supported the research articles that were done to evaluate the elemental compositions and pollution sources in 176 sampling locations through 133 soil and 43 sediments samples along the Egyptian section of the Nile River and Delta e Egypt. "Geochemistry of sediments and surface soils from the Nile delta and lower Nile valley studied by epithermal neutron activation analysis" Arafa [1], "Major and trace element distribution in soil and sediments from the Egyptian central Nile valley" Badawy [2], and "Assessment of industrial contamination of agricultural soil adjacent to Sadat city, Egypt" Badawy [3]. The samples were analyzed by means of instrumental neutron activation analysis INAA and the concentrations in mg/kg of 28 major and trace elements are obtained. The quality control of the analytical measurements was

Geosciences, 2019

To get more data on the geochemistry of Black Sea euxinic sediments, a 50-cm core was collected a... more To get more data on the geochemistry of Black Sea euxinic sediments, a 50-cm core was collected at a depth of 600 m on a Western Black Sea Continental Platform slope. The core contained unconsolidated sediments rich in cocoolithic ooze and mud. Epithermal Neutron and Prompt Gamma Activation Analysis were used to determine the content of nine major (Na, Mg, Al, Si, K, Ca, Ti, Mn, and Fe as oxides) and 32 trace elements (Cl, Sc, V, Cr, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Sn, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Hf, Ta, W, Th, and U) with a precision varying between 3 and 9%. The core contained unconsolidated sediment rich in coccolithic ooze and mud. Previous 210 Pb geochronology suggests an age of ∼1 ky of considered sediments. Major components distribution showed that, except for Cl and Ca, the contents of all other elements are similar to Upper Continental Crust (UCC) and North American Shale Composite (NASC). The distribution of the 32 trace elements showed similari...

Food Analytical Methods, 2017

To get more data regarding the elemental transfer from soil to wine, the neutron activation analy... more To get more data regarding the elemental transfer from soil to wine, the neutron activation analysis was used to determine 35 elements in vineyard chernozem soil and 18 elements in wines from Romanesti and Cricova, Republic of Moldova. Soil elemental content allowed evidencing more similarities between considered soils and the Upper Continental Crust and the World Average Soil as well as to calculate the soil-to-wine transfer factor for 18 of investigated elements. From all 28 trace elements evidenced in soil, only 13, the soluble ones, were found in all wine samples, which finally allowed determining the corresponding transfer factors whose values varied between 0.02 mg/l (U) and 38 mg/l (K). In this regard, all sorts of wines showed a significant concentration of potassium, varying from 370 to 700 mg/l. A subsequent discriminant analysis allowed discriminating all wine samples according to their types: red and white as well as their origin.

Radiation Physics and Chemistry, 2017

The free radicals of irradiated crayfish Astaculs leptodactylus cuticle were studied by X-band el... more The free radicals of irradiated crayfish Astaculs leptodactylus cuticle were studied by X-band electron paramagnetic resonance. The kinetic behaviour as well as the thermal stability of the radiation-induced free radicals in crayfish cuticle were investigated by means of both isothermal and isochronal annealing. Both short, presumable juvenile and long, mature exemplars of freshwater crayfish were investigated. Only the long exemplars cuticle displayed the presence of Mn 2+ ions, very similar to those reported for Mn 2+ ions in calcite. The 200°C isothermal annealing studies attested the existence of a multitude of radical species, some of them being generated during the first minutes of thermal treatment and then partially of totally vanishing. Regardless these peculiarities, the EPR spectrum of 15 kGy irradiated cuticle showed remarkable time stability, its amplitude decreasing with about 18% after more than 16 months of storage at room temperature. The implications of these observations regarding the diversity of irradiation free radicals as well as their suitability to identify gamma radiation decontamination treatment are discussed.

American Journal of Analytical Chemistry, 2017

The levels and compartmentalization of Na,

Journal of African Earth Sciences, 2017

$Research paper thumbnail of \baselineskip =13pt Orientation distribution function of biotite platelets based on optical, thin sections and <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>μ</mi></mrow><annotation encoding="application/x-tex">\mu </annotation></semantics></math>μ-CT image analysis in an Outokumpu (Finland) biotite gneiss: Comparison with neutron diffraction texture analysis$

Russian Journal of Earth Sciences, 2016

The results of the neutron diffraction investigation were compared with similar results obtained ... more The results of the neutron diffraction investigation were compared with similar results obtained by analysing more-CT, high resolution photographic and thin section images of a cylindrical sample of the textured Outokumpu (Finland) biotite gneiss. All data were interpreted by means of corresponding orientation distribution function (ODF). Both Rayleigh test of uniformity and Rao's test for homogeneity of the corresponding ODF confirmed the existence of a real anisotropic distribution of mineralogical phases within investigated specimens. Together with the neutron diffraction pole figures, ODF, unambiguously proved the existence of a lattice as well as of the shape preferred orientations of the mineralogical components of the complex Outokumpu gneiss.