The Roman paintings of Luxor temple in Upper Egypt, dated back to the reign of Emperor Diocletian... more The Roman paintings of Luxor temple in Upper Egypt, dated back to the reign of Emperor Diocletian (late third century AD), are considered one of the most important examples of the use of over-painting techniques in the world. Different plaster layers were applied and painted with scenes of Roman officials over the decorated pharaonic walls from the period of Amenophis III (eighteenth Dynasty, c.1402–1364 BC). In this study, different analytical methods were applied to identify the painting materials that were used for the construction of the over-paintings.
Patterns of chemotaxis by Salmonella typhimurium strain LT-2 to l -amino acids and to several sug... more Patterns of chemotaxis by Salmonella typhimurium strain LT-2 to l -amino acids and to several sugars were quantitated by the Adler capillary procedure. Competition experiments indicated that LT-2 possesses three predominant receptors, or interacting sets of receptors, for amino acids. These were termed the aspartate, serine, and alanine classes, respectively. Studies with strains carrying point and deletion mutations affecting components of the phosphoenolpyruvate: glycose phosphotransferase system (PTS) made unlikely a role in primary reception of d -glucose by the three soluble PTS components, namely HPr, enzyme I, and factor III. A ptsG mutant defective in membrane-bound enzyme IIB′ of the high-affinity glucose transport system was shown to exhibit normal chemotaxis providing pleiotropic effects of the mutation were eliminated by its genotypic combination with other pts mutations or, phenotypically, by addition of cyclic AMP and substrate. A correlation was demonstrated between c...
A quantitative synergetic extraction procedure for cobalt, nickel and palladium from thiocyanate ... more A quantitative synergetic extraction procedure for cobalt, nickel and palladium from thiocyanate aqueous solutions into methyl isobutyl ketone (MIBK), containing 2-benzoylpyridine-2-pyridylhydrazone (BPPH), was studied by flame atomic absorption spectrometry (FAAS) and molecular absorption spectrometry (UV-VIS). Using FAAS, linear calibration graphs were obtained from 0.0-0.5 mg l(-1) Co(II), 0.0-1.5 mg l(-1) Ni(II) and 0.0-2.0 mg l(-1) Pd(II). The reproducibilities were s(r,Co(II))=2.0%, s(r,Ni(II))=1.0% and s(r,Pd(II))=1.3% and the limits of detection were c(L,Co(II))=0.004 mg l(-1), c(L,Ni(II))=0.009 mg l(-1) and c(L,Pd(II))=0.012 mg l(-1). Using UV-VIS method the linear calibration graphs were 0.0-0.5 mg l(-1) for Co(II), 0.0-1.0 mg l(-1) for Ni(II) and 0.0-2.0 mg l(-1) for Pd(II). The reproducibilities were s(r,Co(II))=1.3%, s(r,Ni(II))=1.7% and s(r,Pd(II))=1.0% and the limits of detection were c(L,Co(II))=0.001 mg l(-1), c(L,Ni(II))=0.004 mg l(-1) and c(L,Pd(II))=0.002 mg l(-1). The extraction method is almost free from interferences and has been successfully applied to the determination of cobalt, nickel and palladium in dental alloys.
Abstract Surface sediments and aquatic plants from the River Pinios, Greece, were collected and a... more Abstract Surface sediments and aquatic plants from the River Pinios, Greece, were collected and analyzed for Fe, Mn, Ni, Zn, Cr and Cu, in order to obtain information about the heavy metal contamination of the river. The selected species proved to be good indicators for the monitoring of heavy metals. The distribution of heavy metals in the root, the stem and the leaves of the plants is also investigated.
ABSTRACT In the interdisciplinary domain of conservation science, a critical and selective eye is... more ABSTRACT In the interdisciplinary domain of conservation science, a critical and selective eye is required in order to allow researchers to choose the most effective combination of analytical techniques for each project and, more importantly, to process and analyze the resulting volume of diverse data. The current essay attempts to combine a more traditional workflow for the examination of painted objects with techniques borrowed from the domain of computer science in order to yield the maximum amount of information and make that added knowledge more accessible to the researcher. The project was approached as a case study, regarding a post-Byzantine icon. Three-dimensional digitization with a laser scanning system, X-ray radiography and optical microscopy were applied for the determination of several structural characteristics of the painted surface and the icon's state of preservation. Multispectral imaging was used for the collection of surface spectral data, which were subsequently processed by means of cluster analysis in a novel approach to map the composition of the painted surface. Finally, micro-X-Ray Fluorescence (μ-XRF) was chosen as the primary source for surface pointwise elemental composition data while Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography coupled with Mass Spectroscopy (GC-MS) provided additional assistance in the characterization of materials based on their molecular structure. A custom platform was developed to address the issue of multilevel visualization and assessment of the data, designed to act as a tool for viewing and combining the acquired information. Via this integrated approach valuable information regarding the icon was revealed, including the verification of a prior conservation attempt and partial overpainting, the recording and quantification of the warping of the wooden panel and, finally, the identification of the constituent materials and their spatial distribution.
An efficient ion chromatographic (IC) method was developed for the simultaneous quantitative dete... more An efficient ion chromatographic (IC) method was developed for the simultaneous quantitative determination of Li+, Na+, NH4+, K+, Cs+, Ca2+, Mg2+, Sr2+, Ba2+ and Be2+ in energy drinks, pharmaceutical and drinking water samples by non-suppressed conductometric detection. The separation of ten cations including ammonium was achieved using a cation-exchange column and low conductivity mobile phase. The mobile phase consisted of tartaric acid, dipicolinic acid and boric acid. The separation of the cations was completed in less than 18 min, with a flow rate of 1.2 mL min−1. The separation was not affected by the existence of cations Co2+, Cr3+, Cd2+, Cu2+, Bi3+, Ag+, Fe3+ and Zn2+ in concentrations up to 20 mg L−1. Using an injection volume of 20 μL the obtained detection limits were 0.003 mg L−1, 0.02 mg L−1, 0.01 mg L−1, 0.01 mg L−1, 0.10 mg L−1, 0.01 mg L−1, 0.02 mg L−1, 0.02 mg L−1, 0.003 mg L−1 and 0.1 mg L−1, for Li+, Na+, NH4+, K+, Cs+, Ca2+, Mg2+, Sr2+, Be2+ and Ba2+ respectively...
The flame atomic absorption spectroscopic determination of molybdenum, in aqueous solutions of te... more The flame atomic absorption spectroscopic determination of molybdenum, in aqueous solutions of tetrathiomolybdate (MoS 4 2-, TTM) and paramolybdate species (Mo 7 O 24 2-, PM) has been investigated. A serious signal decrease occurred, if molybdenum has been ...
The Roman paintings of Luxor temple in Upper Egypt, dated back to the reign of Emperor Diocletian... more The Roman paintings of Luxor temple in Upper Egypt, dated back to the reign of Emperor Diocletian (late third century AD), are considered one of the most important examples of the use of over-painting techniques in the world. Different plaster layers were applied and painted with scenes of Roman officials over the decorated pharaonic walls from the period of Amenophis III (eighteenth Dynasty, c.1402–1364 BC). In this study, different analytical methods were applied to identify the painting materials that were used for the construction of the over-paintings.
Patterns of chemotaxis by Salmonella typhimurium strain LT-2 to l -amino acids and to several sug... more Patterns of chemotaxis by Salmonella typhimurium strain LT-2 to l -amino acids and to several sugars were quantitated by the Adler capillary procedure. Competition experiments indicated that LT-2 possesses three predominant receptors, or interacting sets of receptors, for amino acids. These were termed the aspartate, serine, and alanine classes, respectively. Studies with strains carrying point and deletion mutations affecting components of the phosphoenolpyruvate: glycose phosphotransferase system (PTS) made unlikely a role in primary reception of d -glucose by the three soluble PTS components, namely HPr, enzyme I, and factor III. A ptsG mutant defective in membrane-bound enzyme IIB′ of the high-affinity glucose transport system was shown to exhibit normal chemotaxis providing pleiotropic effects of the mutation were eliminated by its genotypic combination with other pts mutations or, phenotypically, by addition of cyclic AMP and substrate. A correlation was demonstrated between c...
A quantitative synergetic extraction procedure for cobalt, nickel and palladium from thiocyanate ... more A quantitative synergetic extraction procedure for cobalt, nickel and palladium from thiocyanate aqueous solutions into methyl isobutyl ketone (MIBK), containing 2-benzoylpyridine-2-pyridylhydrazone (BPPH), was studied by flame atomic absorption spectrometry (FAAS) and molecular absorption spectrometry (UV-VIS). Using FAAS, linear calibration graphs were obtained from 0.0-0.5 mg l(-1) Co(II), 0.0-1.5 mg l(-1) Ni(II) and 0.0-2.0 mg l(-1) Pd(II). The reproducibilities were s(r,Co(II))=2.0%, s(r,Ni(II))=1.0% and s(r,Pd(II))=1.3% and the limits of detection were c(L,Co(II))=0.004 mg l(-1), c(L,Ni(II))=0.009 mg l(-1) and c(L,Pd(II))=0.012 mg l(-1). Using UV-VIS method the linear calibration graphs were 0.0-0.5 mg l(-1) for Co(II), 0.0-1.0 mg l(-1) for Ni(II) and 0.0-2.0 mg l(-1) for Pd(II). The reproducibilities were s(r,Co(II))=1.3%, s(r,Ni(II))=1.7% and s(r,Pd(II))=1.0% and the limits of detection were c(L,Co(II))=0.001 mg l(-1), c(L,Ni(II))=0.004 mg l(-1) and c(L,Pd(II))=0.002 mg l(-1). The extraction method is almost free from interferences and has been successfully applied to the determination of cobalt, nickel and palladium in dental alloys.
Abstract Surface sediments and aquatic plants from the River Pinios, Greece, were collected and a... more Abstract Surface sediments and aquatic plants from the River Pinios, Greece, were collected and analyzed for Fe, Mn, Ni, Zn, Cr and Cu, in order to obtain information about the heavy metal contamination of the river. The selected species proved to be good indicators for the monitoring of heavy metals. The distribution of heavy metals in the root, the stem and the leaves of the plants is also investigated.
ABSTRACT In the interdisciplinary domain of conservation science, a critical and selective eye is... more ABSTRACT In the interdisciplinary domain of conservation science, a critical and selective eye is required in order to allow researchers to choose the most effective combination of analytical techniques for each project and, more importantly, to process and analyze the resulting volume of diverse data. The current essay attempts to combine a more traditional workflow for the examination of painted objects with techniques borrowed from the domain of computer science in order to yield the maximum amount of information and make that added knowledge more accessible to the researcher. The project was approached as a case study, regarding a post-Byzantine icon. Three-dimensional digitization with a laser scanning system, X-ray radiography and optical microscopy were applied for the determination of several structural characteristics of the painted surface and the icon's state of preservation. Multispectral imaging was used for the collection of surface spectral data, which were subsequently processed by means of cluster analysis in a novel approach to map the composition of the painted surface. Finally, micro-X-Ray Fluorescence (μ-XRF) was chosen as the primary source for surface pointwise elemental composition data while Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography coupled with Mass Spectroscopy (GC-MS) provided additional assistance in the characterization of materials based on their molecular structure. A custom platform was developed to address the issue of multilevel visualization and assessment of the data, designed to act as a tool for viewing and combining the acquired information. Via this integrated approach valuable information regarding the icon was revealed, including the verification of a prior conservation attempt and partial overpainting, the recording and quantification of the warping of the wooden panel and, finally, the identification of the constituent materials and their spatial distribution.
An efficient ion chromatographic (IC) method was developed for the simultaneous quantitative dete... more An efficient ion chromatographic (IC) method was developed for the simultaneous quantitative determination of Li+, Na+, NH4+, K+, Cs+, Ca2+, Mg2+, Sr2+, Ba2+ and Be2+ in energy drinks, pharmaceutical and drinking water samples by non-suppressed conductometric detection. The separation of ten cations including ammonium was achieved using a cation-exchange column and low conductivity mobile phase. The mobile phase consisted of tartaric acid, dipicolinic acid and boric acid. The separation of the cations was completed in less than 18 min, with a flow rate of 1.2 mL min−1. The separation was not affected by the existence of cations Co2+, Cr3+, Cd2+, Cu2+, Bi3+, Ag+, Fe3+ and Zn2+ in concentrations up to 20 mg L−1. Using an injection volume of 20 μL the obtained detection limits were 0.003 mg L−1, 0.02 mg L−1, 0.01 mg L−1, 0.01 mg L−1, 0.10 mg L−1, 0.01 mg L−1, 0.02 mg L−1, 0.02 mg L−1, 0.003 mg L−1 and 0.1 mg L−1, for Li+, Na+, NH4+, K+, Cs+, Ca2+, Mg2+, Sr2+, Be2+ and Ba2+ respectively...
The flame atomic absorption spectroscopic determination of molybdenum, in aqueous solutions of te... more The flame atomic absorption spectroscopic determination of molybdenum, in aqueous solutions of tetrathiomolybdate (MoS 4 2-, TTM) and paramolybdate species (Mo 7 O 24 2-, PM) has been investigated. A serious signal decrease occurred, if molybdenum has been ...
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