Oxidation and annealing of thin FeTi layers covered with Pd

The hydrogen storage material FeTi has the disadvantage to lose its sorption capacity in contact with impurities such as O and H O. A possibility to overcome this problem is to coat it with an anti-corrosive layer which is permeable for hydrogen. In this study we prepared FeTi layers covered with a 4 or 20 nm thin Pd layer. We used ion beam and sputter profiling techniques, X-ray photoelectron spectrometry and scanning probe techniques to investigate the response of these bi-layers upon annealing up to 3008C in vacuum, air and 10y5 mbar O . The layered structure remains intact up to 150 °C. At 2008C in air and O , Fe and some Ti move towards the Pd surface where they form oxide regions. At higher temperatures thicker oxide regions, presumably along the Pd grains, are formed. These processes are more pronounced for the case of 4 nm Pd. A model is presented to explain the observed phenomena. We conclude that up to 1508C 4 nm of Pd is sufficient to act as a protective layer. For a temperature of 2008C, 20 nm Pd may still provide sufficient protection against oxidation

Анализ эффективности зарезки боковых стволов на скважинах Катыльгинского нефтегазового месторождения (Томская область)

Работа посвящена анализу эффективности зарезки боковых стволов как самому эффективному методу по увеличению нефтеотдачи на Катыльгинском месторождении и рекомендована к применению в дальнейшем. В paбoте пpиведены cведения o геoлoгo-физичеcкoй и геoлoгo-пpoмыcлoвoй хapaктеpиcтике меcтopoждения, aнaлиз paзpaбoтки меcтopoждения, пoкaзaтели текущегo cocтoяния paзpaбoтки и востоновления скважин разными методами. Пpедcтaвленa cтpуктуpa фoндa cквaжин, oбopудoвaнных электpoцентpoбежными нacocaми. Пpoделанные paбoты пoкaзaли, чтo внедpение данного метода (закрезки боковых стволов) пoзвoляет увеличить дoбычу нефти из бездействующих скважин пpи cнижении ее cебеcтoимocти.The work is devoted to the analysis of the effectiveness of sidetracking as the most effective method for increasing oil recovery at the Katylginskoye field and is recommended for use in the future. The work contains information on the geological, physical, and geochemical properties of the site, the analysis of the location of the site, the indicators of the current state of the development and the development of wells in various ways. The structure of the wells is presented, which are equipped with electric centrifugal pumps. The completed works showed that the introduction of this method (sidetracking) allows increasing the oil output from idle wells while reducing its self-sufficiency

An Evaluation of the Fe-N Phase Diagram Considering Long-Range Order of N Atoms in γ'-Fe4N1-x and ε-Fe2N1-z

The chemical potential of nitrogen was described as a function of nitrogen content for the Fe-N phases α-Fe[N], γ'-Fe4N1-x, and ε-Fe2N1-z. For α-Fe[N], an ideal, random distribution of the nitrogen atoms over the octahedral interstices of the bcc iron lattice was assumed; for γ'-Fe4N1-x and ε-Fe2N1-z, the occurrence of a long-range ordered distribution of the nitrogen atoms over the octahedral interstices of the close packed iron sublattices (fcc and hcp, respectively) was taken into account. The theoretical expressions were fitted to nitrogen-absorption isotherm data for the three Fe-N phases. The α/α + γ', α + γ'/γ', γ'/γ' + ε, and γ' + ε/ε phase boundaries in the Fe-N phase diagram were calculated from combining the quantitative descriptions for the absorption isotherms with the known composition of NH3/H2 gas mixtures in equilibrium with coexisting α and γ' phases and in equilibrium with coexisting γ' and ε phases. Comparison of the present phase boundaries with experimental data and previously calculated phase boundaries showed a major improvement as compared to the previously calculated Fe-N phase diagrams, where long-range order for the nitrogen atoms in the γ' and ε phases was not accounted for

Initial deposition of calcium phosphate ceramic on polystyrene and porlytetrafluoroethylene by rf magnetron sputtering deposition.

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Initial deposition of calcium phosphate ceramic on polyethylene and polydimethylsiloxane by rf magnetron sputtering deposition: the interface chemistry.

Item does not contain fulltextCalcium phosphate (CaP) coatings are well known for their bioactive nature. CaP coated polymeric materials can be used as implant material. For this, a strong adhesion between the coating and substrate is necessary. Because the chemical structure of the interface plays an important role in the coating adhesion, we studied the interface between CaP and the polymers polyethylene (PE) and polydimethylsiloxane (PDMS/silicone rubber). Both untreated and plasma pretreated polymers were used. On PE, a low Ca/P ratio nearby the interface and a high amount of C-O bonds were found on both untreated and plasma pretreated PE. This is the result of phosphate-like groups that are able to bind to the carbon of the PE. PDMS reacts towards the plasma pretreatment by losing CH(3) side groups. Compared to PE, a low amount of C-O bonds is found nearby the interface. Besides, a low Ca/P ratio is found nearby the interface. This is the result of phosphate groups that connect to Si atoms of the PDMS, thereby replacing the CH(3) side groups. The bombardment by negatively charged oxygen ions that are accelerated from the target during the deposition process makes the chemical interaction between the coating and the substrates possible

Determination of phtoelectron attenuation lengths in calcium phosphate ceramic films using XPS and RBS.

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Radio frequency magnetron sputtering deposition of calcium phosphate coatings: the effect of resputtering on the coating composition.

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