The paper presents studies about the process of obtaining the fertilizers based on ammonium phosphates (NH 4 ) 2 HPO 4 and NH 4 H 2 PO 4 with boron added as micronutrient. As boron source was used boric acid, which has been introduced into the neutralization mass at various NH 3 :H 3 PO 4 molar ratio, in order to obtain thermal stable compounds, with a minimum loss of nutritional elements (N, P). The variation of pH, considered the process control parameter, as a function of NH 3 :H 3 PO 4 molar ratio was recorded during the neutralization.Specific analyses has been used in order to determine phosphorus, ammonia nitrogen and boron content in the obtained fertilizers. The thermal behaviour of the fertilizers was studied using TG and DTG. The lowest total mass loss was observed at a 1.5 NH 3 :H 3 PO 4 molar ratio.

The sorption equilibriums of phosphate and thiocyanate anions on isomorphic substituted Mg/Zn-Al-type hydrotalcites were investigated in this study. Langmuir and Freundlich isotherms were used to interpret the equilibrium data for phosphate. The sorption equilibriums of phosphate on Mg 3 Al, Mg 2 ZnAl and Mg 1.5 Zn 1.5 Al hydrotalcites were well described by the Langmuir isotherm. The highest maximum sorption capacities for these adsorbents were as follows: 111, 101 and 95 mg g -1 . The equilibrium constant and standard Gibbs energy changes were also calculated from the sorption data. Standard Gibbs energy changes of about -20 kJ mol -1 indicated that the process might be considered as physical adsorption. The sorption equilibriums of phosphate on isomorphic substituted samples of MgZn 2 Al and Zn 3 Al were well described by the Freundlich isotherm. Thiocyanate showed a relative low affinity for the studied materials, as indicated by both the "S"-shaped isotherms and low sorption capacities. The sorption of phosphate and thiocyanate on the investigated hydrotalcites showed a continuous decrease of the sorption capacity in the following order: Mg

The paper deals with some aspects regarding the behavior of modern and efficient solutions - for rehabilitation of reinforced concrete framed structures. The paper is devoted to experimental studies on carbon fiber reinforced polymer (CFRP) systems used as strengthening solution for reinforced concrete (RC) frames assumed as existing structures, which were tested as un-strengthened and as (CFRP) strengthened structures. Single span and single story frames (scale 1:2) were designed and detailed according to the Romanian design codes from 1970s under which seismic design was inadequate. The RC design and the magnitude of applied forces were ensuring the failure mechanism, of non-strengthened RC frames, by plastic hinges at columns ends. Then the columns were strengthened by using CFRP materials. The experimental program emphasized some important aspects regarding the behavior and failure by debonding of CFRP strengthening materials applied to RC frames. The analysis of experimental data and theoretical values showed up an increase of resistance and stiffness achieved by strengthening.

This paper presents the results of a study carried out in order to produce synthetic ester oils of a mixed structure based on sebacic acid with beneficial tribological properties. These series of unsymmetrical diesters were synthesized using superior aliphatic alcohols such as 2‐ethyl‐hexanol, isodecanol and isotridecanol, along with special alcohols of a complex alkyl‐aryl structure, namely 2‐phenoxy‐ethanol, 2‐[(o‐sec butyl) phenoxy] ethanol and 2‐[(p‐nonyl) phenoxy] ethanol. Also synthesized were symmetric esters based on the complex aliphatic‐aromatic alcohols with pendant aliphatic chain. The variation in the principal properties as a function of both the length of the aliphatic chain introduced by the aliphatic alcohol, and the length and position of the aliphatic pendant chain on the aromatic nucleus of the complex alkyl‐aryl alcohol was assessed. Based on this, it has been possible to obtain fluid products with variable properties. The introduction of the aromatic function in the structure of these diesters led to interesting features, and the superior values recorded for the main tribological characteristics demonstrated their versatility. Copyright © 2006 John Wiley & Sons, Ltd.

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