Oxidation Resistance of Cast Magnesium Alloys

The purpose of the present study was to examine the oxidation of Mg–Al alloys in the atmosphere of oxygen at various temperatures. The basic examination methods used were differential scanning calorimetry (DSC) and thermogravimetry (TG). The results show that the oxide layer can either protect the material against progressive oxidation or it can cause complete disintegration of material. The nature of the oxide layer formed depends on the external conditions, i.e. on the atmosphere, temperature, and type of alloy. A model of the Mg–Al alloy oxidation was calculated from the TG curves.     

Complete classification of raw LIDAR data and 3D reconstruction of buildings

LIDAR (LIght Detection And Ranging) data are a primary data source for digital terrain model (DTM) generation and 3D city models. This paper presents a three-stage framework for a robust automatic classification of raw LIDAR data as buildings, ground and vegetation, followed by a reconstruction of 3D models of the buildings. In the first stage the raw data are filtered and interpolated over a grid. In the second stage, first a double raw data segmentation is performed and then geometric and topological relationships among regions resulting from segmentation are computed and stored in a knowledge base. In the third stage, a rule-based scheme is applied for the classification of the regions. Finally, polyhedral building models are reconstructed by analysing the topology of building outlines, building roof slopes and eaves lines. Results obtained on data sets with different ground point density, gathered over the town of Pavia (Italy) with Toposys and Optech airborne laser scanning systems, are shown to illustrate the effectiveness of the proposed approach.     

Role of the implantable cardioverter-defibrillator in secondary prevention of sudden death in hypertrophic cardiomyopathy patients

1. Despite the frenetic pace of cytochrome P450 (CYP) research, important questions remain about the possible role of xenobiotic-metabolizing CYP in development and cellular homeostasis. 2. The recent experimental development of CYP null mouse lines has provided valuable new models for addressing these issues, as well as providing novel in vivo models to study the precise role of CYP in chemical-mediated toxicity. 3. The present review summarizes results from the three Cyp gene knockout mouse lines generated so far and looks at likely future directions of this research field. 4. Also discussed are null mouse lines with targeted mutations in genes encoding receptors having primary roles in Cyp gene regulation.     

Forecasting risks of natural gas consumption in Slovenia

Efficient operation of modern energy distribution systems often requires forecasting future energy demand. This paper proposes a strategy to estimate forecasting risk. The objective of the proposed method is to improve knowledge about expected forecasting risk and to estimate the expected cash flow in advance, based on the risk model. The strategy combines an energy demand forecasting model, an economic incentive model and a risk model. Basic guidelines are given for the construction of a forecasting model that combines past energy consumption data, weather data and weather forecast. The forecasting model is required to estimate expected forecasting errors that are the basis for forecasting risk estimation. The risk estimation strategy also requires an economic incentive model that describes the influence of forecasting accuracy on the energy distribution systems’ cash flow. The economic model defines the critical forecasting error levels that most strongly influence cash flow. Based on the forecasting model and the economic model, the development of a risk model is proposed. The risk model is associated with critical forecasting error levels in the context of various influential parameters such as seasonal data, month, day of the week and temperature. The risk model is applicable to estimating the daily forecasting risk based on the influential parameters. The proposed approach is illustrated by a case study of a Slovenian natural gas distribution company.     

Adjusting the Structure and Electronic Properties of Carbons for Metal‐Free Carbocatalysis of Organic Transformations

Carbon nanomaterials doped with some other lightweight elements were recently described as powerful, heterogeneous, metal‐free organocatalysts, adding to their high performance in electrocatalysis. Here, recent observations in traditional catalysis are reviewed, and the underlying reaction mechanisms of the catalyzed organic transformations are explored. In some cases, these are due to specific active functional sites, but more generally the catalytic activity relates to collective properties of the conjugated nanocarbon frameworks and the electron transfer from and to the catalytic centers and substrates. It is shown that the learnings are tightly related to those of electrocatalysis; i.e., the search for better electrocatalysts also improves chemocatalysis, and vice versa. Carbon–carbon heterojunction effects and some perspectives on future possibilities are discussed at the end.     

Examining the bentonite produced in a biodiesel refinery process as soil amendment in a well-draining soil

Clean Technologies and Environmental Policy - The expansion of biofuels produced from cooking oils and vegetal oils is expected to increase, together with the production of exhausted clay used in...     

Carrot DNA-methyltransferase is encoded by two classes of genes with differing patterns of expression

There is a wide variety of renal tubular disorders affecting children. Understanding the pathophysiology of each disease assists in the recognition and treatment of these diseases, which can have profound effects on a child's growth and development. We review some of the more common tubular disorders found in children, emphasizing those conditions in which recent advances have been made in understanding of the specific genetic or physiological defect responsible: Fanconi's syndrome, cystinuria, renal tubular acidosis, and the hypokalemic metabolic alkaloses. Current recommendations are presented for diagnosing and treating these conditions.     

Thermodynamic properties of the enzymatic hydrolysis of sunflower oil in high-pressure reactors

On the basis of our previous results, where optimal conditions for the lipase-catalyzed hydrolysis of sunflower oil in a high-pressure batch stirred tank reactor were determined, some thermodynamic and kinetic properties of lipase preparation Lipolase 100T (Aspergillus niger lipase) were established. Activation energy (32.7 kJ/mol) was determined from an Arrhenius plot. Activity of the Lipolase 100T increased between 35 and 50°C, but with further temperature increase thermal deactivation occurred. The thermal deactivation rate constant was 0.40, and the deactivation enthalpy was 123.0 kJ/mol. Because of the desirability of continuous applications of enzyme-catalyzed reactions, a high-pressure continuous flat-shape membrane reactor (HP CFSMR) was designed. Hydrolysis of sunflower oil in this reactor was performed. Maximal conversion in the HP CFSMR was achieved after 1 h. A polysulfone membrane was successfully used as a separation unit, and the highest conversion of FFA was determined at 50°C, 200 bar, and a flow rate for substrates of 0.1 mL/min (each).     

Nitrate removal from electro-oxidized landfill leachate by ion exchange

Treatment of landfill leachates by electrochemical oxidation led to the complete removal of chemical oxygen demand and ammonium nitrogen. However, as result of the ammonium oxidation, the partial formation of nitrate ions was observed. Ion exchange technology was investigated as a polishing step in the treatment of landfill leachates. Removal of nitrate from aqueous solutions was studied using two selective anion exchangers: Purolite A 520E and Purolite A 300, under a fixed bed configuration. The following aspects of the ion exchange system were experimentally analyzed: (i) the influence of the presence of other competitive anions in solution, sulfate and chloride, during the loading step, (ii) the breakthrough point and resin saturation as a function of chloride concentration in the feed stream and, (iii) the efficiency of the regeneration step working with NaCl solutions at several concentrations. After a comparison of the experimental results, it was concluded that the resin Purolite A 300 showed a better behavior. Experimental analysis of the equilibrium isotherms made it possible to determine the equilibrium constant (K=3.21) and the maximum capacity (q(max)=183mgg(-1)), important parameters in the design of the treatment process.