Impact of the atmospheric transmittance and total water vaporcontent in the algorithms for estimating satellite sea surfacetemperatures

Sea surface temperature (SST) algorithms for NOAA AVHRR data can determine SST with rms values of 0.7 K on a global basis. However, this figure is not compatible with the high accuracy of 0.3 K required by climate studies. Biases in the SST product, arising when the factors that increase the optical path-length (absorbents concentration in the atmosphere or viewing angles) are large, cause problems in the use of the split-window formulation for climate monitoring. The reason is that the split-window coefficients currently used are not adequate to cover for all the atmospheric variability. To show this, simulations of channels 4 and 5 of AVHRR/2 of NOAA-11 using a radiative transfer model have been made. The range of atmospheric conditions and surface temperatures introduced in the simulation covers the variability of these parameters on a worldwide scale. From these data, the authors present new split-window coefficients that take into account the atmospheric variability through the ratio of the channel transmittances, or else through the total water vapor content along the path. They also show, using simulated and actual data, that the proposed split-window algorithm has a real global character and represents an improvement over the conventional algorithms     

Myocardial involvement in systemic lupus erythematosus. A noninvasive study of left ventricular function

A relatively high incidence of heart failure is noted among patients with systemic lupus erythematosus (SLE) without clearly defined clinical causes. To evaluate left ventricular performance in patients with SLE without evidence of cardiovascular disease, noninvasive measurement of the systolic time intervals was carried out. Simultaneous recording of the electrocardiogram, phonocardiogram and carotid arterial pulsation were obtained in 25 patients with systemic lupus erythematosus and compared with 22 normal subjects. The patients with SLE had a shorter left ventricular ejection time (P less than 0.05), a longer pre-ejection period (P less than 0.02) and an increased ratio of pre-ejection period/left ventricular ejection time (P less than 0.005). These abnormalities on ventricular function were independent of age, duration of the disease, hypertension, renal involvement, anemia, immunologic activity and corticosteroid treatment. Several etiologic possibilities are discussed and the clinical usefulness of this method to detect and follow-up the cardiac dysfunction in systemic lupus erythematosus is emphasized.     

Reduced Carbon and Energy Footprint in Highway Operations: The Highway Energy Assessment (HERA) Methodology

Global demand for mobility is increasing and the environmental impact of transport has become an important issue in transportation network planning and decision-making, as well as in the operational management phase. Suitable methods are required to assess emissions and fuel consumption reduction strategies that seek to improve energy efficiency and furthering decarbonization. This study describes the development and application of an improved modeling framework – the HERA (Highway EneRgy Assessment) methodology – that enables to assess the energy and carbon footprint of different highways and traffic flow scenarios and their comparison. HERA incorporates an average speed consumption model adjusted with a correction factor which takes into account the road gradient. It provides a more comprehensive method for estimating the footprint of particular highway segments under specific traffic conditions. It includes the application of the methodology to the Spanish highway network to validate it. Finally, a case study shows the benefits from using this methodology and how to integrate the objective of carbon footprint reductions into highway design, operation and scenario comparison.     

Effect of enterocin AS-48 in combination with high-intensity pulsed-electric field treatment against the spoilage bacterium Lactobacillus diolivorans in apple juice

Enterocin AS-48 was tested in apple juice against the cider-spoilage, exopolysaccharide-producing strain Lactobacillus diolivorans 29 in combination with high-intensity pulsed-electric field (HIPEF) treatment (35 kV/cm, 150 Hz, 4 μs and bipolar mode). A response surface methodology was applied to study the bactericidal effects of the combined treatment, with AS-48 concentration and HIPEF treatment time as process variables. At subinhibitory bacteriocin concentrations, microbial inactivation by the combined treatment increased as the bacteriocin concentration and the HIPEF treatment time increased (from 0.5 to 2.0 μg/ml and from 100 to 1000 μs, respectively). Highest inactivation (4.87 logs) was achieved by 1000 μs HIPEF treatment in combination with 2.0 μg/ml AS-48. While application of treatments separately did not protect juice from survivors during storage, survivors to the combined treatment were inactivated within the following 24 h of storage, and the treated samples remained free from detectable lactobacilli for at least 15 days at temperatures of 4 °C as well as 22 °C. The combined treatment could be useful for inactivation of exopolysaccharide-producing L. diolivorans in apple juice.     

Study of ash deposition during coal combustion under oxyfuel conditions

This paper presents a comparative study on ash deposition of two selected coals, Russian coal and lignite, under oxyfuel (O₂/CO₂) and air combustion conditions. The comparison is based on experimental results and subsequent evaluation of the data and observed trends. Deposited as well as remaining filter ash (fine ash) samples were subjected to XRD and ICP analyses in order to study the chemical composition and mineral transformations undergone in the ash under the combustion conditions. The experimental results show higher deposition propensities under oxyfuel conditions; the possible reasons for this are investigated by analyzing the parameters affecting the ash deposition phenomena. Particle size seems to be larger for the Russian coal oxy-fired ash, leading to increased impaction on the deposition surfaces. The chemical and mineralogical compositions do not seem to differ significantly between air and oxyfuel conditions.The differences in the physical properties of the flue gas between air combustion and oxyfuel combustion, e.g. density, viscosity, molar heat capacity, lead to changes in the flow field (velocities, particle trajectory and temperature) that together with the ash particle size shift seem to play a role in the observed ash deposition phenomena.     

Experimental and computational study on the bubble behavior in a 3-D fluidized bed

The results from a two-fluid Eulerian–Eulerian three-dimensional (3-D) simulation of a cylindrical bed, filled with Geldart-B particles and fluidized with air in the bubbling regime, are compared with experimental data obtained from pressure and optical probe measurements in a real bed of similar dimensions and operative conditions. The main objectives of this comparison are to test the validity of the simulation results and to characterize the bubble behavior and bed dynamics. The fluidized bed is 0.193 m internal diameter and 0.8 m height, and it is filled with silica sand particles, reaching a settle height of 0.22 m. A frequency domain analysis of absolute and differential pressure signals in both the measured and the simulated cases shows that the same principal phenomena are reproduced with similar distributions of peak frequencies in the power spectral density (PSD) and width of the spectrum. The local dynamic behavior is also studied in the present work by means of the PSD of the simulated particle fraction and the PSD of the measured optical signal, which reveals as well good agreement between both the spectra. This work also presents, for the first time, comparative results of the measured and the simulated bubble size and velocity in a fully 3-D bed configuration. The values of bubble pierced length and velocity retrieved from the experimental optical signals and from the simulated particle fraction compare fairly well in different radial and axial positions. Very similar values are obtained when these bubble parameters are deduced from either simulated pressure signals or simulated particle volume fraction. In addition, applying the maximum entropy method technique, bubble size probability density functions are also calculated. All these results indicate that the two-fluid model is able to reproduce the essential dynamics and interaction between bubbles and dense phase in the 3-D bed studied.     

Toward remote sensing methods for land cover dynamic monitoring: Application to Morocco

An extensive remotely sensed dataset recently available to the scientific community, The Global Land 1-km AVHRR Project, has been used to examine the possibilities of multi-temporal imagery for mapping and monitoring changes in the biophysical characteristics of land cover. Our goal was to investigate the regional response of the soil-vegetation system to climate in arid zones. We addressed this problemby applying theoretical models to obtain parameters such as Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) from satellite data and by analysing the spatial-temporal dynamics of these parameters. Morocco was selected as the area of study due to its high environmental diversity. This area is also clearly affected by the risk of the advance of the desert. Using The Global Land 1-km AVHRR Project dataset, two methodologies are proposed for the monitoring of land cover dynamics in different areas of interest defined using as mapping criteria the Annual Average of NDVI (AANDVI): (1) The Method of the Area of the Triangle (MAT), based on a form described by the annual evolution of LST and NDVI in each area; (2) the Method of the Slope, which analyses the slope of the line defined by the months of the maximum NDVI and the minimum LST.     

Sakacin M, a bacteriocin-like substance from Lactobacillus sake 148.

The antagonistic activity of Lactobacillus sake 148 was evaluated during its growth on complex broth media and in a semisynthetic defined medium (SDM) with various supplements. The antagonistic activity was a growth-associated property, being detected and quantified when L. sake 148 was grown at either 4, 8, 16, 25 or 32 degrees C. The concentrated culture supernatant of L. sake 148 was subjected to purification by lyophilization and gel filtration. The purification procedure resulted in a small increase in its specific activity (7-fold) and in a low recovery of the original inhibitory activity (8%). Gel filtration analysis of the partially purified activity on Sephadex G-50 revealed an apparent molecular weight of 4640. The partially purified antagonistic activity of L. sake 148 was destroyed by treatment with proteolytic enzymes. However, the antagonistic activity was resistant to heat, having D-values at 121, 135 and 150 degrees C of 23.8, 17.4 and 15.2 min, respectively.     

Critical analysis of the European Union directive which regulates the use of biofuels: An approach to the Spanish case

For more than a decade we have lived in a period where the so-called “sustainability” is crucial and is motivated primarily by the social awareness of achieving a balance between human development and the conservation of the environment. This philosophy has a direct and inevitable impact on business and politics. Governments have long since been developing standards and encouraging various diverse initiatives whose aim is to defend the environment.In recent times, the global debate on the environment has been centred on CO₂ emissions. This gas is the major cause of the “greenhouse effect” and people are more concerned with the idea that the emissions of this gas should be minimized. As a result of this concern, the Kyoto Protocol was enacted and subscribed to by many countries, setting the maximum gas emissions for them.Fossil fuels are a major source of CO₂ emissions. In 2003 the European Union (EU) directive 2003/30/EC [2003/30/EC Directive of the European Parliament and the Council—8th may 2003. On the promotion of the use of biofuels or other renewable fuels for transport] was developed with the aim of promoting the use of biofuels as a substitute for diesel or petrol among European Union countries as well as to contribute to fulfilling the commitments on climate change, security of supply in environmentally friendly conditions and the promotion of renewable energy sources.In order to achieve these goals, the directive forces all EU members to ensure that at least 5.75% of all petrol and diesel fuels sold for transport purposes are biofuels before December 31 of 2010. European Union countries have social and economic characteristics unique to themselves. The energy dependence from foreign sources, the features of the agricultural sector or the degree of industrialization varies greatly from one country to another. In this context, it is questionable whether the obligation imposed by this directive applies to achieve uniform and/or identical goals in each of the countries involved and whether the actions of the various governments are also aligned with these goals.     

Application of a simple algorithm to estimate daily evapotranspiration from NOAA-AVHRR images for the Iberian Peninsula

Evapotranspiration (ET) is a key process in land surface-atmosphere studies. It mainly depends on water availability and incoming solar radiation and then reflects the interactions between surface water processes and climate. In this paper, a methodology for retrieving ET from low spatial resolution remote sensing data is presented. It is based on the evaporative fraction concept, and it has been applied to Advanced Very High Resolution Radiometer (AHVRR) data acquired over the Iberian Peninsula. The methodology does not require other data than the data provided by the satellite and may be applied to areas with almost spatially constant atmospheric conditions and which include wet and dry sub-areas. The comparison with high resolution ET estimation shows a root mean square error (RMSE) of 1.4 mm d^− 1 which is in agreement with the sensitivity analysis of the method. Finally, the methodology has been applied to temporal NOAA-AVHRR images acquired from 1997 to 2002 in order to analyze the seasonal evolution of the daily ET. The temporal study of the ET values realized in this paper shows that the highest ET values are associated with the higher development crops, while the lowest values are related with lower development or null crop. As a conclusion, it is shown that the ET values obtained with the proposed model evolve according to the variations presented in parameters such as surface temperature or vegetation index.