Search results for " powder"
showing 10 items of 93 documents
Nanoscale chemistry and atomic-scale microstructure of a bulk Ni3Sn material built using selective laser melting of elemental powder blends
2021
Abstract Cubic specimens of the intermetallic Ni3Sn compound were built using selective laser melting of elemental powder blends. A specimen built at a laser power of 200 W and a scanning speed of 0.5 m/s was determined to have a homogeneous distribution of Ni and Sn on a mesoscopic scale in spite of a 2 at.% Sn deficiency. Characterization of the microstructure using the HAADF-STEM technique reveals a dispersion of ultrafine Ni particles, nanoscale chemical inhomogeneity and the formation of antiphase nanodomains in the matrix of equiaxed Ni3Sn grains. While a mesoscopic homogeneity of the specimen demonstrates a prospect of additive manufacturing of a bulk intermetallic material using sel…
Inspection of additive-manufactured layered components
2015
Laser powder deposition (LPD) is a rapid additive manufacturing process to produce, layer upon layer, 3D geometries or to repair high-value components. Currently there is no nondestructive technique that can guarantee absence of flaws in LPD products during manufacturing. In this paper a laser ultrasonic technique for in-line inspection of LPD components is proposed. Reference samples were manufactured from Inconel and machined flaws were created to establish the sensitivity of the technique. Numerical models of laser-generated ultrasonic waves have been created to gain a deeper understanding of physics, to optimize the set-up and to verify the experimental measurements. Results obtained on…
Inactivation of dried spores of Bacillus subtilis 168 by a treatment combining high temperature and pressure
2019
International audience; Specific treatments combining high temperatures of up to 150 °C and moderate pressure of up to 0.6 MPa have been applied to Bacillus subtilis 168 spores conditioned at different aw levels (between 0.10 and 0.70) corresponding to different residual water contents within the spore core. The spores were treated as a dry powder in a pressurized nitrogen environment or in water/glycerol solutions.These thermodynamic conditions were intended to prevent any water evaporation from the spore core during time/temperature treatments.Our results clearly show that retaining liquid water in the core by applying pressure during the treatment resulted in greater spore destruction (b…
Synthesis, characterization and thermal properties of new aromatic quaternary ammonium bromides
2004
Series of new aromatic R 2R′ 2N +Br - (R=benzyl, 4-methylbenzyl, 2-phenylethyl, 3-phenylpropyl; R′=ethyl, methyl, isopropyl) or RR′ 2NH +Br --type (R=benzyl, R′=isopropyl) quaternary ammonium bromides were prepared by using novel synthetic route in which a formamide (N,N-diethylformamide, N,N-dimethylformamide, N,N-diisopropylformamide) is treated with aralkyl halide in presence of a weak base. The compounds were characterized by 1H-NMR and 13C-NMR spectroscopy and mass spectrometry. Structures of the crystalline compounds were determined by X-ray single crystal diffraction, and in addition the powder diffraction method was used to study the structural similarities between the single crysta…
Friction stir consolidation of aluminum machining chips
2017
Friction stir consolidation (FSC) is a solid-phase manufacturing process that consolidates metal powder, chips, or scraps into solid blocks via severe plastic deformation and solid state welding. It has the potential to be a more economical and âgreenâ process to recycle metal waste. In this study, solid discs were made from AA6061 aluminum alloy machining chips by FSC. The progression of the process was revealed by analyzing the motion of the tool, consolidating force, power history, and macro/microstructure of discs produced from a series of partial consolidation experiments. A bowl-shaped recrystallized zone in the vertical cross-sections of the disc products was observed and conside…
Comparison of the chemopreventive efficacies of garlic powders with different alliin contents against aflatoxin B1 carcinogenicity in rats
2004
Garlic (Allium sativum) is well known for its beneficial effects on health and particularly for its chemopreventive potential against cancer. The present study was designed to compare the chemopreventive efficacies of several garlic powders with various levels of alliin, a precursor of active sulfur compounds. For this purpose we used the medium-term hepatocarcinogenesis protocol (resistant hepatocyte model), which allows the detection of preneoplasic foci expressing the placental form of glutathione S-transferase (GST-P) as an end-point. Rats were fed diets containing three garlic powders (5% of the diet) with various alliin contents for 3 weeks. Garlic powders were obtained from bulbs gro…
The Effect of Fluctuating Temperature on the Stability of Turoctocog Alfa for Hemophilia A
2019
Abstract Background and objective Factor VIII (FVIII) is indicated for the prevention or treatment of bleeding in patients with hemophilia A. FVIII product stability under high and fluctuating temperatures is important, particularly for patients who reside in, or travel to, regions with high ambient temperatures, as they may remove their product from the refrigerator and return it, unused, multiple times. We evaluated the effect of variable temperature storage conditions, including up to 40 °C, on the stability of the recombinant FVIII product, turoctocog alfa. Methods Turoctocog alfa dry powder stability was assessed when moved between storage conditions of 5 °C (ambient humidity) and 40 °…
Metallic lead recovery from lead-acid battery paste by urea acetate dissolution and cementation on iron
2009
Abstract A suitable hydrometallurgical and environmentally friendly process was studied to replace the currently used practices for recycling lead-acid batteries via smelting. Metallic lead was recovered by cementation from industrial lead sludge solutions of urea acetate (200 to 500 g/L) using different types of metallic iron substrates (nails, shaving or powder) as reducing agents. Under specific operating conditions, up to 99.7% of lead acid battery paste, mainly composed of PbSO4, PbO2 and PbO·PbSO4 species, was converted to metallic lead.. The conversion of the metallic lead and rate of the cementation reaction were strictly dependent on the type of iron substrate used as the reductant…
The comparison of seven different methods to quantify the amorphous content of spray dried lactose
2006
The purpose of this work was to verify the usefulness, advantages and disadvantages of seven methods that are widely used to detect, and quantify the amorphous contents in pharmaceutical solids. Here, StepScan DSC, a type of modulated temperature calorimetry method, was applied for the first time to quantify amorphicity. The comparison of the analytical methods was undertaken with real (non-artificial) test samples, i.e. spray-dried lactose samples with various degrees of crystallinity. In these samples, it was essential that the amorphous and the crystalline portions are not present as separate particles, which is the case when physical (artificial) mixtures of totally amorphous and totall…
Inhaled Surfactant in the treatment of accidental Talc Powder inhalation: a new case report
2011
Abstract The use of talcum powder is incorrectly part of the traditional care of infants. Its acute aspiration is a very dangerous condition in childhood. Although the use of baby powder has been discouraged from many authors and the reports of its accidental inhalation have been ever more rare, sometimes new cases with several fatalities have been reported. We report on a patient in which accidental inhalation of baby powder induced severe respiratory difficulties. We also point out the benefits of surfactant administration. Surfactant contributed to the rapid improvement of the medical and radiological condition, preventing severe early and late complications and avoiding invasive approac…