Abstract  This study investigated meteorological, physical, and chemical characteristics of 2 severe Hwangsa (Asian dust, maximum average of PM10 above 1000 mu g m(-3)) observed in Seoul, the capital city of Korea, during 30 similar to 31(st) May, 2008 (DSS2008) and 25 similar to 26(th) December, 2009 (DSS2009). DSS2008 and DSS2009 had a same source region and route. However, they have different meteorological conditions. DSS2009 had a shorter travel time from the source region to Korea and shorter duration time in Korea than DSS2008 due to a strong winter Siberian anticyclone. One of DSS2008 sample was affected by not only Asian dust but also a long-range transported haze due to consecutive influx after low pressure passed while DSS2009 sample collected only dust aerosol. For both cases, the mass concentration of coarse particles (PM10-1) increased by 3 similar to 14 times compared to that during non Asian dust period, however, that of fine particles (PM1) increased only in DSS2008. For DSS2008 water-soluble ion balance between anions and cations in fine mode was close to 1:1 while cations were higher than anions in coarse mode. NH4 (+) and Ca2+ were found to be the main contributing factors for the neutralization. Cl- loss was observed about 60% indicating an active interaction of Na+ with pollutants. Reconstruction of chemical compositions showed relatively high concentrations of secondary pollutants (NH4NO3 and (NH4)(2)SO4), CaCO3, and Ca(NO3)(2) compared to that during non Asian dust period. DSS2009 exhibited the typical characteristics of Asian dust having a high concentration of Ca2+ with higher equivalent concentration of cations than anions in all size bins. Cl- loss was hardly observed. The secondary pollutants were lower than that of non Asian dust cases. The result of reconstruction of ionic components indicated the CaCO3 derived from soil particle, CaSO4, and Ca (NO3)(2) were dominant in DSS2009.

Abstract  The direct-quadrature method of moment (DQMOM) and transported PDF (TPDF) approaches have been adopted to predict the precise structure of turbulent CH(4)-air piloted jet flame. To realistically account for precise turbulent flame structure of turbulent jet flame, the mathematical formations of the transported PDF method are based on the joint-composition PDF model together with I FM mixing process. To minimize computational burden, the steady flamelet library is utilized to account for non-equilibrium chemistry. For unconditional means and conditional scatters for species mass fraction and temperature, comparison between predictions and measurement are made. Numerical results obtained by DQMOM and TPDF are reasonably well agreed with experimental data in terms of the mean and rms of species mass fraction and probability density function.

Abstract  An experimental study was performed to analyze the combustion processes of JP-8 and fossil Diesel fuel in an optically-accessible single-cylinder heavy-duty diesel engine equipped with a high pressure common-rail injection system. In terms of emission, JP-8 emitted less smoke with more HC and NOx. Direct imaging and two-color thermometry were applied to verify the emission trend for both fuels. The combustion process was characterized by means of image analysis focusing on the luminosity intensity and its spatial distribution (flame spatial fluctuation (FSF) and flame non-homogeneity (FNH)). The results from the two-color thermometry were analyzed by the flame temperature and KL factor distribution. From the combustion process analysis of the direct imaging, it was verified that JP-8 had a longer ignition delay compared to fossil Diesel fuel regardless of injection pressure. However, flame luminosity of JP-8 was vanished more rapidly. The flame luminosity intensity analysis showed that fossil Diesel fuel had stronger flame luminosity overall and duration of visible flame luminosity was longer than JP-8. This implies that fossil Diesel fuel had more diffusion dominant combustion. From the flame luminosity variation rate analysis, decreasing rate of flame luminosity for JP-8 was higher compared with fossil Diesel fuel, showing that oxidation rate of JP-8 was much higher than fossil Diesel fuel. From FSF and FNH analysis, JP-8 showed lower value for both FSF and FNH in the later stage of combustion, because the later stage of combustion with JP-8 has less jet structure in comparison with fossil Diesel fuel. The flame temperature field from two-color thermometry showed that locally high temperature region existed with JP-8. KL factor distribution of JP-8 was distributed more uniformly with a relatively lower level of KL intensity in comparison with fossil Diesel fuel in the late stage of combustion. (C) 2012 Elsevier Ltd. All rights reserved.

Abstract  We describe a new method for the manufacture of single walled carbon nanotube (SWCNT)-based electrical devices on flexible substrates. The method involves the deposition of a SWCNT films onto polydimethylsiloxane (PDMS) substrates from rigid substrates using the adhesive property of PDMS. This method is similar to the conventional dry transfer method, which is based on surface-energy modification, except that our method involves mechanical transfer using the adhesive property of PDMS under peculiar conditions. The gas- sensing characteristics of the resulting transferred SWCNT films are presented, showing, for example, that typical flexible sensors exhibit a sensitivity of 17.4% for 4-ppm NO2 in a vacuum at room temperature. The performances of the devices are slightly reduced when they are bent to a curved profile with a bending radius of 2?cm (15.9%). The field-emission properties are also investigated. From these emitters, the SWCNTs can be turned on with a field as low as 0.9?V/mu m, and an emission current density of 0.75?mA/cm2 at 1.2?V/mu m can be attained. Thus, a method for the fabrication of flexible devices is established, which should find practical applications in electronic devices. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Abstract  DME (dimethyl ether, CH3OCH3) is a potentially attractive fuel for gas turbines because of low pollutant emission and easy transportation and storage. However, the high flame speed and a low ignition temperature of DME present a high risk of flash-back, which can be a potentially serious problem. To solve this problem and achieve better combustion performance, the present study contrived a new fuel nozzle for DME that can obtain optimal combustion of DME in the gas turbine combustor, thereby achieving cost reduction of power generation, enhancement in reliability of power plants and diversification of usable fuel. The configuration of a fuel nozzle for DME and a design method using Wobbe Index are both described in detail. The combustion performance of the newly developed DME fuel nozzle was verified through a gas turbine combustion test and the results showed considerable improvement in the performance of NOx and CO emissions and the prevention of flash-back. (C) 2012 Elsevier Ltd. All rights reserved.

Abstract  This study aims to investigate the combustion characteristics of mixed fuel of liquefied propane gas (LPG) and biodiesel under compression ignition (Cl) in an effort to develop highly efficient and environmentally friendly mixed fuel-based Cl engines. Although LPG fuel is known to be eco-friendly due to its low CO2, emission, LPG has not yet been widely applied for highly efficient Cl engines because of its low cetane number and is usually mixed with other types of Cl-friendly fuels. In this study, a number of experiments were prepared with a constant volume chamber (CVC) setup to understand the fundamental combustion characteristics of mixed fuel with LPG and biodiesel in two weight-based ratios and exhaust gas recirculation (EGR) conditions. The results from the current investigations verify the applicability of mixed fuel of LPG and biodiesel in Cl engines with a carefully designed combustion control strategy that maximizes the benefits of the mixed fuel. Based on the results of this study, ignition is improved by increasing the cetane value by using higher blending ratios of biodiesel. As the blending ratios of biodiesel increased, CO and HC decreased and CO2 and NOx increases.

Abstract  Smoke inhalation injury is frequently accompanied by cyanide poisoning that may result in substantial morbidity and mortality, and methods are needed to quantitatively determine extent of airway injury. We utilized a 3-D endoscopic frequency- domain optical coherence tomography (FD-OCT) constructed with a swept-source laser to investigate morphological airway changes following smoke and cyanide exposure in rabbits. The thickness of the mucosal area between the epithelium and cartilage in the airway was measured and quantified. 3-D endoscopic FD-OCT was able to detect significant increases in the thickness of the tracheal walls of the rabbit beginning almost immediately after smoke inhalation injuries which were similar to those with combined smoke and cyanide poisoning. (C) 2011 Optical Society of America

Abstract  We examined the effects of vitamin C in Pluronic F127 on diabetic wound healing. Full-thickness excision skin wounds were made in normal and diabetic Wistar rats to evaluate the effect of saline, saline plus vitamin C (antioxidant sol), Pluronic F127, or Pluronic F127 plus vitamin C (antioxidant sol-gel). The rate of wound contraction, the levels of epidermal and dermal maturation, collagen synthesis, and apoptosis production in the wound tissue were determined. In vitro data showed that after 6 hours of air exposure, the order of the scavenging abilities for HOCl, H2O2, and O-2 (-) was antioxidant sol-gel > antioxidant saline > Pluronic F127 = saline. After 7 and 14 days of wound injury, the antioxidant sol-gel improved wound healing significantly by accelerated epidermal and dermal maturation, an increase in collagen content, and a decrease in apoptosis formation. However, the wounds of all treatments healed mostly at 3 weeks. Vitamin C in Pluronic F127 hastened cutaneous wound healing by its antioxidant and antiapoptotic mechanisms through a good drug delivery system. This study showed that Pluronic F127 plus vitamin C could potentially be employed as a novel wound-healing enhancer.

Abstract  The evolution of organic aerosols (OA) in Mexico City and its outflow is investigated with the nearly explicit gas phase photochemistry model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere), wherein precursor hydrocarbons are oxidized to numerous intermediate species for which vapor pressures are computed and used to determine gas/particle partitioning in a chemical box model. Precursor emissions included observed C3-10 alkanes, alkenes, and light aromatics, as well as larger n-alkanes (up to C25) not directly observed but estimated by scaling to particulate emissions according to their volatility. Conditions were selected for comparison with observations made in March 2006 (MILAGRO). The model successfully reproduces the magnitude and diurnal shape for both primary (POA) and secondary (SOA) organic aerosols, with POA peaking in the early morning at 15-20 mu g m(-3), and SOA peaking at 10-15 mu g m(-3) during mid-day. The majority (>= 75 %) of the model SOA stems from reaction products of the large n-alkanes, used here as surrogates for all emitted hydrocarbons of similar volatility, with the remaining SOA originating mostly from the light aromatics. Simulated OA elemental composition reproduces observed H/C and O/C ratios reasonably well, although modeled ratios develop more slowly than observations suggest. SOA chemical composition is initially dominated by delta-hydroxy ketones and nitrates from the large alkanes, with contributions from peroxy acyl nitrates and, at later times when NOx is lower, organic hydroperoxides. The simulated plume-integrated OA mass continues to increase for several days downwind despite dilution-induced particle evaporation, since oxidation chemistry leading to SOA formation remains strong. In this model, the plume SOA burden several days downwind exceeds that leaving the city by a factor of >3. These results suggest significant regional radiative impacts of SOA.

Abstract  Infrared radiative emissions by carbon dioxide (CO2) and nitric oxide (NO) are the major cooling mechanisms of the lower thermosphere. During geomagnetically active periods, the NO density and cooling rate in the auroral regions increase significantly as a result of particle precipitation and Joule heating. Previous studies have shown that the time for NO density to recover to quiet time levels is longer than that of the thermosphere temperature or density recovery. This study explores the implications of these different recovery rates for the post-storm thermosphere. Thermosphere densities retrieved from the CHAMP and GRACE accelerometer measurements and NO cooling rates measured by TIMED/SABER are used to examine their variations during the post-storm period of the October 2003 geomagnetic storms. It was found that thermosphere densities at both CHAMP and GRACE altitudes recovered rapidly and continuously decreased below the quiet time densities during the post-storm period, especially at middle latitudes. Compared with the quiet time values, the maximum depletion in the CHAMP and GRACE densities after the storm is about 23-36%, and the estimated decrease of thermospheric temperature is as large as 70-110 K. Our analysis suggests that the elevated NO cooling rate, resulting from the slower recovery of NO densities in the post-storm period, is a plausible cause for this apparent post-storm overcooling of the thermosphere.

Abstract  The present work presents a measurement uncertainty evaluation according to Guide to the Expression of Uncertainty in Measurement (GUM) of the concentration of the cations K+ and Li+ and anions NO3-2 and SO4-2 in fine airborne particulate matter, refers to particles less than 2.5 mu m in diameter (PM2.5), as measured by ion chromatography (US-EPA 300 method). The GUM method is not typically used to report uncertainty. In general, the analytical results only report the measurement's standard deviation under repetition as an uncertainty; thus, not all sources of uncertainty are considered. In this work, the major sources of uncertainty regarding the measurements were identified as contributions to linear least square regression lines, repeatability, precision, and trueness. The expanded uncertainty was approximately 20% for anions and cations. The largest contribution to uncertainty was found to be repeatability.

Abstract  The elemental composition of laboratory chamber secondary organic aerosol (SOA) from glyoxal uptake, alpha-pinene ozonolysis, isoprene photooxidation, single-ring aromatic photooxidation, and naphthalene photooxidation is evaluated using Aerodyne high-resolution time-of-flight mass spectrometer data. SOA O/C ratios range from 1.13 for glyoxal uptake experiments to 0.30-0.43 for alpha-pinene ozonolysis. The elemental composition of alpha-pinene and naphthalene SOA is also confirmed by offline mass spectrometry. The fraction of organic signal at m/z 44 is generally a good measure of SOA oxygenation for alpha-pinene/O(3), isoprene/high-NO(x), and naphthalene SOA systems. The agreement between measured and estimated O/C ratios tends to get closer as the fraction of organic signal at m/z 44 increases. This is in contrast to the glyoxal uptake system, in which m/z 44 substantially underpredicts O/C. Although chamber SOA has generally been considered less oxygenated than ambient SOA, single-ring aromatic- and naphthalene-derived SOA can reach O/C ratios upward of 0.7, well within the range of ambient PMF component OOA, though still not as high as some ambient measurements. The spectra of aromatic and isoprene-high-NO(x) SOA resemble that of OOA, but the spectrum of glyoxal uptake does not resemble that of any ambient organic aerosol PMF component.

Abstract  BACKGROUND: The ongoing emission of nitric oxide (NO) is a serious persistent environmental problem, because it contributes to atmospheric ozone destruction and global warming. A novel and effective system was developed for the complete treatment of NO from flue gases. The system features NO absorption by FeII(EDTA) and biological denitrification in a rotating drum biofilter (RDB). RESULTS: After 100 mg L1 FeII(EDTA) was added to the nutrient solution, the results show that the NO removal efficiency was improved from 70.56% to 80.15%, the optimal temperature improved from 32.5 degrees C to 40.5 degrees C, and the pH improved from 7.5 to 8.08.3. A maximum NO removal efficiency of 96.5% was achieved when 500 mg L1 FeII(EDTA) was used in the nutrient solution. CONCLUSION: This experiment demonstrates that FeII(EDTA) could not only improve the mass transfer efficiency of NO from gas to liquid, but also serve as an electron donor for the biological reduction of NO to N2. The new integrated treatment system seemed to be a promising alternative for the complete treatment of NO from flue gases. (c) 2012 Society of Chemical Industry

Abstract  The objective of the work presented in this paper is to contribute to the development of CHP systems based on conventional diesel engines but fuelled with pyrolysis oil or pyrolysis oil derived fuels. Experiments have been carried out using a one-cylinder, 20 kW(e) diesel engine, which was adapted to enable the feeding of different fuels and the monitoring of its performance. Apart from the introduction of a completely new stainless steel fuel injection system also specific measures have been implemented to overcome the difficult and slow ignition behavior of pyrolysis oil. Pyrolysis oil could be successfully combusted provided the air inlet temperature was increased to 100-120 degrees C at an engine compression ratio of 17.6. This temperature can be reduced by approximately 40 degrees C when the compression ratio is increased to 22.4. Generally, pyrolysis oil fuelling led to an increase in CO emission and a decrease in NOx emission. Apparently, peak temperatures in the cylinder are lower upon fuelling pyrolysis oil. A 'duration' experiment of 40 h was carried out while fuelling pyrolysis oil, without any notable effect on flue gas emissions and fuel consumption. This is considered as a very promising result, but further long-term testing will be required. (C) 2012 Elsevier Ltd. All rights reserved.

Abstract  The aim of this study was to investigate the influence of the vertical position of a motorway on the pollutant concentrations in the vicinity of the motorway. Therefore, a near-road monitoring campaign was performed along two adjoining motorway stretches: one motorway at ground level and a motorway flyover. PM2.5 and nitrogen oxides (NO, NO2 and NOx) were measured at both sides of the motorway on a 30-min resolution. In addition, EC (elemental carbon) was measured on both sides of the road on a daily basis using low volume samplers and thermal–optical transmission (TOT) analysis of filters. PNC (particle number concentration) was measured at one side. The measurement locations on each side of the road were located at 29 m and 102 m from the motorway at ground level and at 60 m and 120 m from the motorway flyover. Pollution roses, showed increased average concentrations in the direction of the road for nitrogen oxides and PM2.5. The impact of road traffic appeared to be higher at ground level compared to the flyover. The difference in concentration between both sides of the road for PM2.5, NO, NO2 and NOx was analysed using linear mixed models. The concentration difference, which can be seen as the contribution of road traffic to the pollutant concentration, was calculated taking into account prevailing wind directions. The results indicate that taking into account confounding parameters (time of day, day of the week, distance to the road and wind speed), the contribution of the motorway traffic to pollutant concentrations is significantly higher when the motorway is at ground level. Furthermore, time of day and day of the week also have a significant effect on the concentration difference. The linear mixed model estimated a reduced road increment at the motorway flyover compared to the ground level motorway of 119 ppb for NO, 29 ppb for NO2 and 3.5 μg m−3 for PM2.5. taking into account confounding parameters. The highest EC and PNC concentrations were measured downwind of the motorway at ground level.

Abstract  The Global Ozone Monitoring Instrument (GOME) was launched in April 1995 on ESA's ERS-2 platform, and the GOME Data Processor (GDP) operational retrieval algorithm has produced total ozone columns since July 1995. We report on the new GDP5 spectral fitting algorithm used to reprocess the 16-year GOME data record. Previous GDP total ozone algorithms were based on the DOAS method. In contrast, GDP5 uses a direct-fitting algorithm without high-pass filtering of radiances; there is no air mass factor conversion to vertical column amount. GDP5 includes direct radiative transfer simulation of earthshine radiances and Jacobians with respect to total ozone, albedo closure and other ancillary fitting parameters - a temperature profile shift, and amplitudes for undersampling and Ring-effect interference signals. Simulations are based on climatological ozone profiles extracted from the TOMS Version 8 database, classified by total column. GDP5 uses the high-resolution Brion-Daumont-Malicet ozone absorption cross-sections, replacing older GOME-measured flight model data. The semi-empirical molecular Ring correction developed for GDP4 has been adapted for direct fitting. Cloud preprocessing for GDP5 is done using updated versions of cloud-correction algorithms OCRA and ROCINN. The reprocessed GOME GDP5 record maintains the remarkable long-term stability of time series already achieved with GDP4. Furthermore, validation results show a clear improvement in the accuracy of the ozone product with reduced solar zenith angle and seasonal dependences, particularly in comparison with correlative observations from the ground-based network of Brewer spectrophotometers.

Abstract  We study the interactions between atmospheric boundary layer (ABL) dynamics and atmospheric chemistry using a mixed-layer model coupled to chemical reaction schemes. Guided by both atmospheric and chemical measurements obtained during the DOMINO (Diel Oxidant Mechanisms in relation to Nitrogen Oxides) campaign (2008), numerical experiments are performed to study the role of ABL dynamics and the accuracy of chemical schemes with different complexity: the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4) and a reduced mechanism of this chemical system. Both schemes produce satisfactory results, indicating that the reduced scheme is capable of reproducing the O-3-NOx-VOC-HOx diurnal cycle during conditions characterized by a low NOx regime and small O-3 tendencies (less than 1 ppb per hour). By focusing on the budget equations of chemical species in the mixed-layer model, we show that for species like O-3, NO and NO2, the influence of entrainment and boundary layer growth is of the same order as chemical production/loss. This indicates that an accurate representation of ABL processes is crucial in understanding the diel cycle of chemical species. By comparing the time scales of chemical reactive species with the mixing time scale of turbulence, we propose a classification based on the Damkohler number to further determine the importance of dynamics on chemistry during field campaigns. Our findings advocate an integrated approach, simultaneously solving the ABL dynamics and chemical reactions, in order to obtain a better understanding of chemical pathways and processes and the interpretation of the results obtained during measurement campaigns.

Abstract  Background: Currently, a new generation of synthetic pulmonary surfactants is being developed that may eventually replace animal-derived surfactants used in the treatment of respiratory distress syndrome. Enlightened by this, we prepared a synthetic peptide-containing surfactant (Synsurf) consisting of phospholipids and poly-l-lysine electrostatically bonded to poly-l-glutamic acid. Our objective in this study was to investigate if bronchoalveolar lavage (BAL)-induced acute lung injury and surfactant deficiency with accompanying hypoxemia and increased alveolar and physiological dead space is restored to its prelavage condition by surfactant replacement with Synsurf, a generic prepared Exosurf, and a generic Exosurf containing Ca2+. Methods: Twelve adult New Zealand white rabbits receiving conventional mechanical ventilation underwent repeated BAL to create acute lung injury and surfactant-deficient lung disease. Synthetic surfactants were then administered and their effects assessed at specified time points over 5 hours. The variables assessed before and after lavage and surfactant treatment included alveolar and physiological dead space, dead space/tidal volume ratio, arterial end-tidal carbon dioxide tension (PCO2) difference (mainstream capnography), arterial blood gas analysis, calculated shunt, and oxygen ratios. Results: BAL led to acute lung injury characterized by an increasing arterial PCO2 and a simultaneous increase of alveolar and physiological dead space/tidal volume ratio with no intergroup differences. Arterial end-tidal PCO2 and dead space/tidal volume ratio correlated in the Synsurf, generic Exosurf and generic Exosurf containing Ca2+ groups. A significant and sustained improvement in systemic oxygenation occurred from time point 180 minutes onward in animals treated with Synsurf compared to the other two groups (P < 0.001). A statistically significant decrease in pulmonary shunt (P < 0.001) was found for the Synsurf-treated group of animals, as well as radiographic improvement in three out of four animals in that group. Conclusion: In general, surfactant-replacement therapy in the animals did not fully restore the lung to its prelavage condition. However, our data show that the formulated surfactant Synsurf improves oxygenation by lowering pulmonary shunt.

Abstract  Biodiesel has proved to be an environment friendly alternative fuel for diesel engine because it can alleviate regulated and unregulated exhaust emissions. However, most researchers have observed a significant increase in NOx emissions with biodiesel when compared to petrodiesel. The exact cause of this increase is still unclear; however, researchers believe that the fuel properties have been shown to effect the emissions of NOx. The present work reviews the effect of fuel properties and composition on NOx emissions from biodiesel fuelled engines. The paper is organised in three sections. The first section deals with the NOx formation mechanisms. In the following section, the reasons for increased NOx emissions of biodiesel fuel are discussed. After this, the influence of composition and fuel properties on NOx emissions from biodiesel fuelled engines has been reviewed. Finally, some general conclusions concerning this problem are summarised and further researches are pointed out. (c) 2012 Elsevier Ltd. All rights reserved.

Abstract  The possibility of the application of nano- and microparticles of iron as the carriers for palladium and platinum catalysts are shown. An increase in the efficiency of the catalytic activity by 2-5 times is found to be reached by way of microstirring of the reaction medium using magnetic fields with a variable direction of the intensity gradient. The possibility of manufacturing composite materials of iron-silver and iron-gold is also shown, which can be used in electric engineering. The techniques for producing catalytic and conducting materials based on the chemical depositing of certain metals on iron particles are described. Galvanic methods were shown to be used for the development of metal shells on the particles of magnetic current-conducting materials. The copper sliding contacts with microinclusions of graphite and iron manufactured using the proposed methods are characterized by a specific electric resistance of rho = 2-3 x 10(-6) Ohm cm (for comparison, the specific electric resistance of graphite sliding contacts is rho = 800 x 10(-6) Ohm cm) at a simultaneous increase in the wear resistance and, as a consequence, in the service life by 12-15 times. The possibility of the chemical passivation of the surface of nano- and microparticles of iron is shown to prevent their reacting with diluted nitric acid. Iron particles were studied to be used for obtaining contrasting X-ray anatomical specimens of the intraosteal blood-vascular system. A technological application of a magnetic field with a variable direction of the intensity gradient was proposed to increase the density of filling the capillary network with contrasting particles, which allows increasing the density of the filling of the intraosteal capillary network by up to 75% with respect to the volume.

Abstract  MILD (Moderate and Intensive Low oxygen Dilution) combustion is a novel approach to reducing NOx emissions and improving combustion efficiency in fossil fuels power plants. It is characterized by elevated temperature and high dilution of reactants and strong recirculation inside the combustion chamber which produce a low temperature increase, thus reducing NOx formation. The main differences with conventional combustion concern the chemical reactions that take place in almost the entire volume of the combustion chamber and the uniformity of both temperature and the chemical species concentration. For this reason advanced turbulence-chemistry interaction models with detailed kinetic mechanisms are required to accurately simulate MILD by means of CFD calculations. The main aim of this work is to deepen the influence of turbulence-chemistry interaction on pulverized coal MILD combustion and to understand which models are more accurate and suitable to reproduce the process. In particular, two turbulence-chemistry interaction models are analyzed. On one hand, a conventional model based on infinitely fast chemistry Eddy Dissipation Model with a two-step global kinetic mechanism is considered. On the other hand, an advanced model based on finite rate chemistry Eddy Dissipation Concept is considered and used with both a global and detailed kinetic mechanisms. The results are finally compared with an experimental test-case. From the comparison, advanced turbulence- chemistry models used with complex kinetic mechanisms give, as expected, the best agreement with numerical results, despite the higher computational resources required. (C) 2011 Elsevier Ltd. All rights reserved.

Abstract  Phyllorhiza punctata (P. punctata) is a jellyfish native to the southwestern Pacific. Herewith we present the biochemical and pharmacological characterization of an extract of the tentacles of P. punctata. The tentacles were subjected to three freezethaw cycles, homogenized, ultrafiltered, precipitated, centrifuged and lyophilized to obtain a crude extract (PHY-N). Paralytic shellfish poisoning compounds such as saxitoxin, gonyautoxin-4, tetrodotoxin and brevetoxin-2, as well as several secretory phospholipase A2 were identified. PHY-N was tested on autonomic and somatic neuromuscular preparations. In mouse vas deferens, PHY-N induced phasic contractions that reached a peak of 234 +/- 34.7% of control twitch height, which were blocked with either 100 mu m of phentolamine or 1m m of lidocaine. In mouse corpora cavernosa, PHY-N evoked a relaxation response, which was blocked with either L-NG- Nitroarginine methyl ester (0.5 m m) or 1m m of lidocaine. PHY-N (1, 3 and 10 mu g ml(-1)) induced an increase in tonus of the biventercervicis neuromuscular preparation that was blocked with pre-treatment of galamine (10 mu m). Administration of 6 mg kg(-1) PHY-N intramuscularly produced death in broilers by spastic paralysis. In conclusion, PHY-N induces nerve depolarization and nonspecifically increases neurotransmitter release. Copyright (C) 2011 John Wiley & Sons, Ltd.

Abstract  This paper describes comparative studies on the determination of di-n-butyl phosphate (DBP) by ion chromatography (IC) and gas chromatography (GC) techniques in spent solvent of PUREX process used for the reprocessing of spent nuclear fuels. The ion chromatography method involves the separation of DBP from 30% TBP-NPH (tri-n- butylphosphate diluted in normal paraffin hydrocarbon) containing heavy metal ion like uranium and nitric acid by extraction of DBP into alkaline medium. DBP was subsequently eluted by ion- exchange separation in ion chromatography column and followed by suppressed conductivity detection. DBP is quantified to a lower limit of about 1 ppm with 3% RSD. However, in order to determine DBP by gas chromatography technique DBP is first quantitatively converted into its volatile and stable derivatives by using diazomethane prior to analysis by GC. Results obtained with ion chromatographic technique are compared with those of obtained by standard gas chromatographic technique. It was observed that IC technique involves minimum steps and is much faster than GC analysis. The effect of mobile phase flow rate on the detector response, retention time, and column pressure are also investigated.

Abstract  Throughout Europe and the USA, forest ecosystem functioning has been impacted by long-term excessive deposition of acidifying compounds. In this study, we report on trends in stand deposition and soil solution fluxes of inorganic nitrogen (N) and sulphur (S) compounds over a 17-year period (1994-2010) in five ICP Forests monitoring plots in Flanders, northern Belgium. Deposition was dominated by N, and primarily NH4+. Deposition of SO42- and NH4+ declined by 56-68% and 40-59% respectively. Deposition of NO decreased by 17-30% in deciduous forest plots, but remained stable in coniferous forest plots. The decrease of N and S deposition was parallelled by a simultaneous decline in base cation (BC = Ca2+ + K+ + Mg2+) deposition, resulting in a 45-74% decrease of potentially acidifying deposition. Trends in soil solution fluxes of NH4+, NO3-, SO42- and BC mirrored declining depositions. Nitrate losses below the rooting zone were eminent in both coniferous forest plots and in one deciduous forest plot, while net SO42- release was observed in two deciduous forest plots. Critical limits for BC/Al ratio were exceeded at the three plots on sandy soils with lower cation exchange capacity and base saturation. Soil solution acid neutralizing capacity increased but remained negative, indicating that soil acidification continued, as the start of recovery was delayed by a simultaneous decrease of BC depositions and short-term soil buffering processes. Despite substantial reductions, current N deposition levels still exceed 4-8 times the critical load for safeguarding sensitive lichen species, and are still 22-69% above the critical load for maintaining ground vegetation diversity. (C) 2012 Elsevier Ltd. All rights reserved.