[en] Performance and financial constraints are pushing modern DAQs (Data Acquisition Systems) to use distributed cluster environments instead of monolith one-box systems. Inside clusters application communication layers should support outstanding high performance requirements. We are currently investigating different network protocols that could meet the requirements of high speed/low latency peer-to-peer communication within DAQ clusters. We have carried out various performance measurements with TCP and SCTP over Fast and Gigabit Ethernet. We are focusing on Ethernet Technologies, because this transport medium is broad deployed, cost efficient and it has much better cost/throughput ratio than other available communication alternatives (e.g.: Myrinet, Infiniband). During this study, a protocol performance measurement application with different peer transport components has been developed. In the first part of the paper, we give a short comparison of the two protocols (SCTP and TCP), and an introduction of the transport layer structure developed. Later on we discuss the performance results of single/multi-stream peer-to-peer communication, give overview about application code transition possibilities from application developer point of view between the two protocols, and draw conclusions about usability

[en] Various aspects of Di 2-ethylhexylphosphoric acid (DEHPA) synthesis were investigated using ¹H, ¹³C and ³¹P NMR techniques. The first step of the present work consists of the identification and the determination of DEHPA, its derivatives and other intermediates in the reaction mixture without previous separation or purification. The second step is devoted to the study of the effects of the main factors, i.e. the reaction temperature, ROH/P₂O₅ mole ratio, the reaction time and the presence of some additives upon the reaction. The spectra and the distribution of the reaction products were also discussed. As an important conclusion which can be withdrawn from the present investigations one can suggest that the -26 ppm triplet is due to the presence of triphosphorus compounds. Such compounds should result from the direct interaction between 2-ethylhexanol and the polymeric phosphorus anhydride during the first 40 minutes after the beginning of the reaction. Pyrophosphates i.e. diphosphorus intermediates and the monoester which exhibit a relatively higher stability were also yielded

[en] An original way for TBP synthesis was developed by combining two classical reactions. This process consists in esterifying butanol with o-phosphoric acid in presence of small amounts of promoting agent. The reaction occurs without solvent and under pressure. The promoter seems to play an enhancing role and presents a synergetic effect. Its action is obvious only for optimal conditions when TBP yield can reach 60%mol after 5 to 10 hours. This process is interesting by the fact that the process is accelerated by comparison to the classical esterification which is known to be very slow and that the process uses hydrated phosphoric acid which is a very low cost reagent and non-corrosive material. According to the operating conditions, one can favour selectively the formation of mono-, di- or triester and this process can be applied in manufacturing other phosphoric extraction agents

[en] The aqueous solution is contacted with an aminated compound of low solubility in water, for instance a trialkylamine, and the complex formed is separated. Application is made to the recovery of organic phosphorus compounds in effluent for reuse in uranium or plutonium extraction or for extraction of degradation products of TBP

No abstract available

[en] The present work deals with the optimisation study of TBP synthesis process by phosphoric acid. This way of synthesis is more advantageous than POCL3 or P2O5 as phosphatant agents. these latters are toxic and dangerous for the environnement. The optimisation study is based on a series of 16 experiences taking into account the range of variation of the following parameters : temperature, pressure, reagents mole ratio, promoter content. the yield calculation is based on the randomisation of an equation including all parameters. the resolution of this equation gave a 30% TBP molar ratio. this value is in agreement with that of experimental data

[en] The extraction of uranium(VI) through a W/O/W liquid membrane containing DEHPA was studied in the counter transport system. The optimum stable conditions of W/O emulsion were determined; the optimum concentrations of surfactant span 80 and paraffine oil were 2 Vol. %, respectively. The extraction results showed that more than 95 % of uranium(VI) was extracted during 10 minutes when the carrier concentration was 4 Vol. %, internal aqueous phase; IN-Hsub(2)SOsub(4) solution, external aqueous phase; pH 2 and mixing speed; 350 rpm. (Author)

[en] This work consists on the synthesis of dibutylphosphoric acis (DBP) by reaction of butanol with phosphorus pentoxid and on its separation by liquid-liquid extraction. It also deals with the characterization of DBP by some physicochemical analysis methods such as : chromatography, pH-metry and infrared and ultraviolet spectrophotometries. this study showed essentialy, that DBP can be formed in an appreciable amount (55%) when the reaction is realised with butanol/pentoxid molar ratio upper than 3 at temperature of 95 C

[en] The present work summarizes preliminary experiments dealing with the analysis of the main organophosphorus extracting agents TBP, DEHPA and TOPO widely used in hydrometallurgy and particulary in uranium one treatment. In order to ovoid the thermodegraduation processes of such compounds, an adequate combination of vaporization temperature and the carrier gas flow, i,e, the time contact of the compounds in column must be made. In this context, the present work was justly achieved in order to elaborate a only the separation but also the accurate determination of the compounds dealt with. One can remark that maintaining constant the temperature and slightly varying the flow velocity of the carrier gas, the peaks of TBP and butanol were better separated. Nevertheless, a limitation may appear when nitrogen flow is raised up to 30m1/mn. This is essentially due to the lose polarity and their analogous chemical behaviours. Thus one can conclude that such compounds can be easily determined in the ranges of 0-60% for D2EHPA, for TOPO and 24% for TBP. The determination accuracy for all compounds varies between 0.005 and 0.12%. Thus, one can conclude that the organophosphorus extracting agents such as TBP, D2EHPA and TOPO can be easily determined without previous purification. The isothermal conditions are strongly recommemded in this case because of the quickness of the technique. The secondary products resulting from the synthesis process do not affect greatly the determinations of such compounds and their accuracies

No abstract available