Fluorescence diagnostics of oil pollution in coastal marine waters by use of artificial neural networks

We discuss the problems with and the real possibilities of determining oil pollution in situ in coastal marine waters with fluorescence spectroscopy and of using artificial neural networks for data interpretation. In general, the fluorescence bands of oil and aquatic humic substance overlap. At oil concentrations in water from a few to tens of micrograms per liter, the intensity of oil fluorescence is considerably lower than that of humic substances at concentrations that typically are present in coastal waters. Therefore it is necessary to solve the problem of separating the small amount of oil fluorescence from the humic substance background in the spectrum. The problem is complicated because of possible interactions between the components and variations in the parameters of the fluorescence bands of humic substances and oil in water. Fluorescence spectra of seawater samples taken from coastal areas of the Black Sea, samples prepared in the laboratory, and numerically simulated spectra were processed with an artificial neural network. The results demonstrate the possibility of estimating oil concentrations with an accuracy of a few micrograms per liter in coastal waters also in cases in which the contribution from other organic compounds, primarily humic substances, to the fluorescence spectrum exceeds that of oil by 2 orders of magnitude and more.     

Optoacoustic technique for noninvasive monitoring of blood oxygenation: a feasibility study

Replacement of invasive monitoring of cerebral venous oxygenation with noninvasive techniques offers great promise in the management of life-threatening neurologic illnesses including traumatic brain injury. We developed and built an optoacoustic system to noninvasively monitor cerebral venous oxygenation; the system includes a nanosecond Nd:YAG laser and a specially designed optoacoustic probe. We tested the system in vitro in sheep blood with experimentally varied oxygenation. Our results demonstrated that (1) the amplitude and temporal profile of the optoacoustic waves increase with blood oxygenation in the range from 24% to 92%, (2) optoacoustic signals can be detected despite optical and acoustic attenuation by thick bone, and (3) the system is capable of real-time and continuous measurements. These results suggest that the optoacoustic technique is technically feasible for continuous, noninvasive monitoring of cerebral venous oxygenation.     

The eidochromatic transform for color-image coding.

We introduce the eidochromatic transform as a tool for improved lossy coding of color images. Many current image-coding formats (such as JPEG 2000) utilize both a color-component transform (relating values of different image components at a single location) and a wavelet or other spatial transform (relating values of a single-image component at proximate, but different image locations). The eidochromatic transform further reduces redundancy by relating image values simultaneously across color components and in the two spatial dimensions. Our approach is to introduce an additional transform step following the color-component and spatial transforms. In tests, this step reduced the overall static entropy of the chrominance components of quantized transformed images by up to 40% or more. Combined with JPEG 2000's modeling and coding method, the eidochromatic transform was found to reduce the size of lossily coded color images by up to 27% overall.     

Creativity and Innovation through Multidisciplinary and Multisectoral Cooperation

This paper explores the relation between creativity, innovation and new product development in multidisciplinary and multisectoral settings. We claim that the development of innovative products benefits from the generation of a high number of creative ideas. Moreover, we argue that the idea generation process can be particularly fruitful within collaborative multidisciplinary environments, where firms and Science and Technology institutions coexist and cooperate. Our approach draws on existing literature to investigate the creativity and idea generation process within the frame of multisectoral and multidisciplinary cooperation initiatives, involving firms and Science and Technology related institutions. We then call upon our own empirical work to identify conditions favourable to those processes and some issues that affect the fulfilment of the creative potential that exists in multidisciplinary groups.     

The mushroom bodies of Drosophila melanogaster: an immunocytological and golgi study of Kenyon cell organization in the calyces and lobes

Golgi impregnations reveal a variety of dendritic morphologies amongst Kenyon cells in the mushroom bodies of Drosophila melanogaster. Different morphological types of Kenyon cells contribute axon-like processes to five divisions of the medial and vertical lobes. Four of these divisions have characteristic affinities to antibodies raised against aspartate, glutamate, and taurine. A newly described posterior subdivision of the medial lobe, here named the betac lobe with its vertical branch alphac, comprises glutamatergic Kenyon cells that are probably homologous to glutamatergic Kenyon cells in the cockroach and honey bee, and are the last neurons to differentiate. The first neurons to differentiate, which supply the gamma lobe, are equipped with clawed dendritic specializations and are the structural homologues of clawed class II Kenyon cells supplying the gamma lobes in cockroaches and honey bees. Three intermediate divisions lie between the betac lobe and gamma lobe. These are, from the back towards the front, the beta lobe, the beta' lobe, and a narrow division between beta' and gamma called the beta" lobe. The fused calyx of the Drosophila mushroom body is comparable to the double calyces of Hymenoptera, here exemplified by a basal taxon, Diprion pini. Further similarities between the hymenopteran calyces and those of Drosophila are suggested by the segregation of different types of Kenyon cell dendrites within the calyx neuropil. The organization of afferents from the antennal lobes also defines regions in the Drosophila calyx that may be homologous to the lip and basal ring regions of the honey bee calyces. As in honey bees, GABAergic processes densely invade Drosophila's calyces, which also contain a sparse but uniform distribution of octopaminergic elements. Microsc. Res. Tech. 62:151-169, 2003.     

Pt black powder as a heat exchanger at ultralow temperature

We have studied a series of Pt black sinters. They were produced under different pressure and temperature conditions, resulting in packing fractions ranging from 40 up to 60%. The samples were sintered to a highly polished copper surface of 2.0×1.3 cm² with a thickness from 25 m up to 1 mm. Dependent on the presintering temperature a specific surface area between 90 m²/cm³ and 180 m²/cm³ is found. The electrical resistivity was about 114 ·cm at room temperature and 50 ·cm at 4.2 K for 40% density and 56 ·cm and 23 ·cm for 60% density, respectively. The microscopic structure of several samples was characterized by electron microscopy and neutron diffraction techniques. A porosity around 0.5 m and an anisotropic particle size of only 70 Å was found. This indicates that this material can well be used as a heat exchanger at ultralow temperature.     

Role of bottom sediments in the secondary pollution of aquatic environments by heavy-metal compounds

The results of long‐term investigations into the concentrations of some heavy metals (Fe, Mn, Cu, Zn, Pb, Cr, and Cd) in the bottom sediments of the Dnieper reservoirs and the Dnieper–Bug estuary are considered. Maximum quantities of the metals studied are characteristic of southern water bodies located within industrial zones (the Zaporozh’e and Kakhovka reservoirs as well as the Dnieper–Bug estuary). The highest concentrations of the metals studied occurred in the clay silts (Fe, 11 600–32 400; Mn, 1504–3450; Cu, 38.9–85.5; Zn, 89.8–186.5; Cr, 48.6–193.0; and Cd, 1.9–4.4 mg kg^‐1 dry weight). Accumulation of heavy metals in the bottom sediments is an important factor in the self‐purification of aquatic environments. However, this process is reversible and therefore provides a constant threat of secondary water pollution. Secondary water pollution is observed in summer and autumn when water consumption increases. The concentrations of heavy metals increase by a factor of 1.5–3 after the drawdown of the water level. The main reason for the rise in the concentrations of metals is exchange between the bottom sediments and the water column. The rate of heavy metal migration is connected with the forms of occurrence in solid substrates and pore solutions in the bottom sediments, as well as with physico‐chemical conditions arising at the sediment/water boundary. Therefore, our investigations concentrated on the study of the fractional distribution of heavy metals among solid substrates and their forms of occurrence in interstitial solutions. This distribution depends, most of all, on the chemical properties of metals as well as the chemical and mineralogical composition of the sediments and the chemical properties of pore solutions. Most of the supply of Mn, Zn, Fe, and Cd is associated with oxides and hydroxides of iron and manganese (Mn, 74–93%; Zn, 43–70%; Fe, 27–59%; and Cd, 28–41%). Most copper and chromium is bound to organic matter and to scarcely soluble minerals. In the interstitial solutions studied, metals (except manganese) are found mainly as complex compounds with dissolved organic matter of a different molecular weight. Nevertheless, the fraction of complexes with a relatively low molecular weight (500–5000 Da) prevailed (40–70%). Dissolved manganese in the pore solutions consists chiefly of free (hydrated) ions Mn²⁺ (80–95%). The results obtained were used for a comparative evaluation of heavy metal mobility and the exchange ability of their associated compounds in the bottom sediment–water system.     

Methylation of Phenol by Methanol on Acidic Zeolite H–Y Investigated by in situ CF MAS NMR Spectroscopy

In situ ¹³C MAS NMR spectroscopy under continuous-flow (CF) conditions was applied to study the mechanism of the methylation of phenol by methanol on acidic zeolite H–Y. Ex situ GC-MS was used as a complementary technique to confirm the nature of the chemical species remaining on the catalyst after the in situ MAS NMR investigations. Anisole and cresols were observed as the main reaction products in the initial step of the reaction. By use of the stopped-flow (SF) technique, the consecutive transformation of anisole to cresols was observed at the reaction temperature of 413K indicating that anisole is an unstable primary product and an important intermediate.