Changes in the central and peripheral circulatory system in response to the cold: own studies using impedance plethysmography and Doppler ultrasound

The aim of the study was to determine the cardiovascular response to continuous (4 °C for 60 min) and intermittent (10 min at 4?°C and 10 min at room temperature alternately) exposure to the cold in 30 healthy young men. The subjects were equipped with a set of identical clothing (insulation 2.1 clo) and during the stay in the chamber and outside performed the same activities, i.e., walking on a treadmill at a speed of 0.5?km/h. The tests included assessing the central circulatory system using the Holter system and assessing the peripheral circulatory system using impedance plethysmography and Doppler ultrasound. The analysis of the parameters that describe the central and peripheral circulation poses a difficulty in determining which variant of exposure constitutes a greater load on the circulatory system. It should be noted that even the conditions used in the study may cause adverse effects in the cardiovascular system.     

Extraction and Characterization of Nanocrystalline Cellulose from Doum (<Emphasis Type="Italic">Chamaerops humilis</Emphasis>) Leaves: A Potential Reinforcing Biomaterial

The aim of this investigation was to extract nanocrystalline cellulose (NCC) from Moroccan Doum fibers (Chamaerops humilis) by chemical treatment to examine their potential for use as reinforcement fibers in bionanocomposite applications. The chemical composition, morphological and structural properties of the Doum fibers was determined at different stages of chemical treatment. Morphological (transmission electron microscopy and scanning electron microscopy), structural characterization (X-ray diffraction, Fourier transformed infrared), thermal characterization (thermogravimetric analysis). The suspension electrostatic stabilization (zeta potential) of NCCs was also carried out. The results of these characterization analysis found that average size of the NCC is 220 nm in length and 11 nm in diameter, with high crystallinity index (93 %), a thermal stability comparable to that of untreated Doum fibers (degradation temperature 340 °C), which is reasonably promising for the use of these nanofibers in reinforced-polymer manufacturing, and a good stability in water suspension that it allows their utilization such as reinforcement of the water-soluble polymers to prepare the bio-nanocomposite.     

Yield and quality of charcoals from olive mill residues and its stone and pulp fractions: An enhanced comparative study

Pyrolysis is a promising way to upgrade large amounts of residues from olive oil processing into charcoal. Pyrolysis of the stone and pulp fractions needed to be investigated before conclusions could be drawn. We subjected the olive stone fraction, the pulp fraction, and a mixture of the two to dynamic pyrolysis and isothermal pyrolysis at 360°C. We characterized the charcoals resulting from isothermal pyrolysis at 360°C for different durations in terms of the fixed-carbon content (FCC), carbon content (CC), and high heating value (HHV). We found that charcoal yield from the pulp was higher than that from the stones, which were 38.1% and 32.9%, respectively, after pyrolysis for 360 min. This seemingly unexpected result was due to the high contents of ash (6.22%) and extractives (13%) in the pulp, which remained completely and partially undecomposed, respectively, in the charcoals and are accounted for when calculating yields. However, charcoals obtained from the stones were of higher quality than charcoals from the pulp, with lower ash content and higher FCC, CC, and HHV. In particular, the FCC, CC, and HHV after pyrolysis for 360 min were 73.2%, 74.4%, and 30.2 MJ/kg for the stones and only 61.8%, 63.2%, and 25.9 MJ/kg for the pulp, respectively. Depending on the required quality of the final charcoal, our results help decide whether to pyrolyse the entire olive residues or only one of the two fractions, more likely the stones.     

Assessment of heat-inactivated marine Aspergillus flavus as a novel biosorbent for removal of Cd(II), Hg(II), and Pb(II) from water

Environmental Science and Pollution Research - A novel marine fungus was isolated and classified as Aspergillus flavus strain EGY11. The heat-inactivated form of isolated Aspergillus flavus was...     

Photocatalytic demulsification of oil/water emulsions containing nonionic surfactant

Environmental Science and Pollution Research - Separation of oil-water (OW) emulsions is investigated using a photocatalytic demulsification approach. Experiments were conducted using two types of...     

Toxic impact of nanomaterials on microbes,plants and animals

Nanotechnology has many potential applications in medical, agriculture, electronic and sports industries. Nonetheless, there is actually little knowledge on toxic effects of nanomaterial. Here we review nanotoxicity, action mechanisms and fate of nanomaterials. We discuss the impact of nanotoxicity on microbes, plant, animal and human health, and factors like size, shape, surface charge, composition, ionic concentration and physiological. We explain the detection of nanotoxicity at cell and genome levels. Toxicities of commercial nanomaterials, risk management, rules and regulations regarding marketed nanoproducts are also summarized.     

Dynamics of heavy-metal transfer between biotic (Cytheria chione and Cerastoderma edule) and abiotic (water and sediment) components in marine environment (Bay of Martil, Moroccan Mediterranean coast)

This study deals with the transfer of heavy metals (Hg, Cd, Pb, Cr, Ni, Ti, Zn, and Cu) between abiotic and biotic components (Cytheria chione and Cerastoderma edule) in the inshore intertidal zones of Tetouan/Martil over 2 yr of investigation (1992-1994). Analysis of the heavy-metal accumulation kinetics in Cytheria chione and Cerastoderma edule shows that their highest contents occur during the spring-summer period when an important proliferation of the plankton biomass occurs. However, the accumulation of Cd is higher during the period between winter and spring. In general, heavy-metal concentrations are higher at Cytheria chione than at Cerastoderma edule. These results, according to previous studies, suggest the presence of significant correlations and dynamic reciprocal transfer of heavy metals among seawater, sediment, and molluscs. They also suggest that the level of contamination of decreasing heavy metals follows the sequence: sediment, organisms, and water. Among the molluscs investigated, the variability of the thallium (Tl) contents is difficult to detect due to the very weak presence of this metal in the analysed tissues.     

Photocatalytic degradation of Chicago Sky Blue 6B and Benzopurpurin 4B using titanium dioxide thin film

Aqueous solutions of azo dyes undergo degradation to form harmless intermediates and colorless products following irradiation by visible light in the presence of titanium dioxide thin films. The dyes that were studied in this work are： Chicago Sky Blue 6B and Benzopurpurin 4B. Results obtained indicated that complete mineralization of the dyes took place under the experimental conditions. There was an increase in conductivity after the complete mineralization experiments possibly indicating the formation of ions such as NO3^- and SO4^2-. Chemical oxygen demand（COD） measurements show a decrease in organic matter for both dyes following complete degradation. The effect of how changing experimental conditions such as pH, temperature and starting concentrations of dyes affected the rate of dye degradation was measured. There was an increase in the rate of disappearance of the dye color at lower pH. High concentrations of dye solutions reauired Iona dearadation time.     

Short-term, real-time forecasting of hourly ozone, NO2 and NO levels by means of multiple linear regression modelling

Conclusions  The results are at least as good as those obtained with much more sophisticated models. Furthermore, the models can be easily run on a simple PC. This approach may provide a good diagnostic network (as seen in Bilbao) with real-time, short-term prognostic capabilities for a given location. The models have been built for Bilbao and are applicable only in this location. However, using the same methodology, similar results could be obtained in other environments if a good diagnostic network is available. The full paper is published in the Internet journal ‘Gate to EHS (Environmental and Health Science)’, in June 2001, and can be called up and cited by way of the DOI:http://dx.doi.org/10.1065/ehs2001.06.009