Atomic Layer Deposition of Aluminum Nitride Using Tris(diethylamido)aluminum and Hydrazine or Ammonia

Aluminum nitride (AlN _x ) films were obtained by atomic layer deposition (ALD) using tris(diethylamido) aluminum(III) (TDEAA) and hydrazine (N₂H₄) or ammonia (NH₃). The quartz crystal microbalance (QCM) data showed that the surface reactions of TDEAA and N2H4 (or NH₃) at temperatures from 150 to 225°C were self-limiting. The rates of deposition of the nitride film at 200°C for systems with N₂H₄ and NH₃ coincided: ~1.1 Å/cycle. The ALD AlN films obtained at 200°C using hydrazine had higher density (2.36 g/cm³, 72.4% of bulk density) than those obtained with ammonia (2.22 g/cm³, 68%). The elemental analysis of the film deposited using TDEAA/N2H4 at 200°C showed the presence of carbon (~1.4 at %), oxygen (~3.2 at %), and hydrogen (22.6 at %) impurities. The N/Al atomic concentration ratio was ~1.3. The residual impurity content in the case of N₂H₄ was lower than for NH₃. In general, it was confirmed that hydrazine has a more preferable surface thermochemistry than ammonia.     

Effect of sublimation epitaxy conditions on the properties of (SiC)<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>(AlN)<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions

We have studied the effect of growth conditions on the growth rate, chemical composition, and conductivity type of films of (SiC)_{1 ? x} (AlN) _x semiconductor solid solutions produced by sublimation epitaxy on 6H-SiC substrates in an argon + nitrogen atmosphere.     

Acoustic Emission Testing of Early Generation of Defects in CFRP Samples under Static and Thermal Loading

Russian Journal of Nondestructive Testing - Static tests of the samples of Torayca T700, T800 carbon fiber reinforced plastics consisting of nine monolayers with $$\left[ { \pm...     

Comparative in vitro Studies of the Topoisomerase I Inhibition and Anticancer Activities of Metallated N-Confused Porphyrins and Metallated Porphyrins

Using the original approach, a series of metallated N-confused porphyrins and metallated porphyrins have been synthesized and characterized. For all the synthesized porphyrins, in vitro studies of cytotoxic activity against K562, U937, HL-60, Jurkat, A549 and HeLa cancer cell lines, the ability to induce apoptosis and effects on the cell cycle as well as the kinetics of proliferative activity of porphyrins and their respective metallated complexes in real time have been developed. The inhibitory activity of metallated porphyrins against human topoisomerase I and the possible mechanism of inhibition have been carried out by modelling using molecular docking.     

Structure and properties of PP/TiO2 based polymer nanocomposites

ABSTRACT

The transient pulse testing is used in bridgewire-charges to measure the electrothermal performance non-destructively rather than by the conventional inspection. The conventional inspection has the disadvantage of destruction with a number of products tested, while the transient pulse testing can give a dynamic electrothermal curve at a user's command. In addition, the transient pulse testing can be used to measure a passel of products one by one rather than by a statistical spot check. Unfortunately, a statistic spot check cannot provide the firing reliability of products efficiently. The other way round, the transient pulse testing may put an end to the possibility of loss for users absolutely. The reason that the transient pulse testing is not devastating for products is that these mixtures of a product have a required thermal stability, and then are simultaneously able to be responded reliably by a very small pulse current. We have determined that these red matches based on Si/Pb₃O₄/DDNP mixtures electrothermal responsibility curves. Firing performance, measurements of the transient pulse testing, and electrothermal parameters are presented in this paper.     

Radial Distribution of the Temperature in a Well

Journal of Engineering Physics and Thermophysics - A theoretical investigation of the radial temperature distributions in the upward and downward flows of fluid in the borehole of a production well...     

Detecting hazardous sources of acoustic-emission signals using the estimated energy of clusters

A method for detecting hazardous sources of acoustic-emission (AE) signals by the level of their energy activity using clustering by digitized signal shape was considered. The influence of the distance between a source and an AE transducer on the energy of recorded AE signals was analyzed. The energy distribution median of signals in a cluster was proposed for evaluating the hazard of an AE signal source. The application of the developed method was tested based on the example of the analysis of AE inspection data on the welding of steel specimens with incomplete fusion and a crack at the root of a weld seam. This testing confirms the results of the fractographic inspection of a defective weld seam.     

Clustering of sources of acoustic-emission signals by the leading-edge rise rate

It is shown that the method of clustering by the leading-edge rise rate of the envelope of an acoustic-emission (AE) signal makes it possible to reduce the time of calculation of the coordinates of flaws as compared to the clustering by shape. The developed technique realizes the on-line localization of massive flows of AE signals with an accuracy sufficient for practical application. The practical parameters of using the method for operation on a steel sheet with a simulator obtained for a statically loaded duralumin specimen and for welding of steel specimens with aluminum and titanium inserts are considered.     

Acoustic-emission study of the possibilities of localizing flaws of a welded joint during cooling

A method of localizing acoustic-emission signals from flaws of a welded joint during its cooling is considered. Aluminum and titanium inserts were used to simulate flaws of the welded joint. The developed technique of clustering made it possible to exclude noise accompanying the processes of welding and cooling the welded joint. The welded specimens were tested on an MTS-50 loading machine. At the finishing stage, specimens with double-sided welded joints containing titanium inserts were subjected to metallographic analysis.