[en] Published in summary form only

[en] The present invention relates to a procedure for the valorization of uranium ores contained in a phosphatic stuff. The procedure consists in a heat conditioning of the ores before acid etching and in a subsequent conventional acid etching, using especially SO₂ of H₂SO₄ solutions

[en] Glassy carbon (GC) possesses excellent thermal resistance but is apt to oxidation. This significantly limits its potential applications in high-temperature environments. This paper investigates the surface deterioration mechanisms of three types of GCs prepared at different heat treatment temperatures (HTT) and/or machining conditions. After cyclic heating-cooling, the polished GC made under a higher HTT (GC-G) demonstrated better anti-deterioration performance than that under a lower HTT (GC-K). In the GC-K, oxidation readily proceeds along the depth direction during the heating-cooling process, leading to the reduction of Young’s modulus and catastrophic surface cracks; whereas in the GC-G, the more ordered graphite sites provide resistance to the thermal oxidation induced surface deterioration. Cutting-induced defects can significantly reduce Young’s modulus and accelerate the deterioration. (paper)

[en] The double loop electrochemical potentiokinetic reactivation (EPR-DL) technique was used to determine the degree of sensitization (DOS) of AISI 316 type alloys where the molybdenum content was replaced both partial and totally by vanadium. The double loop potentiokinetic polarization curves in 0.5 M H₂SO₄ with the addition of 0.01 M KSCN at 25 C were obtained to calculate the DOS via reactivation and passivation charges ratio (Ca/Cp). Before the electrochemical experiments were carried out, the alloys were heat treated at 680 C for 1.5 and 10 hours to produce a sensitized microstructure with chromium and molybdenum depleted zones close to the grain boundaries. The results showed that the 1.5 hour heat treated partially modified alloys displayed less DOS than the totally modified ones, while the 10 hour heat treated totally modified alloys showed less DOS than the partially modified ones. The results are consistent with a beneficial effect of vanadium when it replaces the molybdenum in the alloys. Transmission electron microscopy was used in order to correlate the electrochemical and microstructural results. (orig.)

[en] Effects of heat treatment, gamma irradiation, and combined treatments on the shelf-life of fresh avocados (Persea americana L.). Experiments to determine the effective irradiation conditions to prolong the shelf-life of fresh avocados were conducted at the centre for the Application of Isotopes washed and dried, then divided into 4 groups, namely for control (A), dipped in hot water at 40⁰C for 20 minutes (heat treatment, B), irradiated at a dose of 25 Gy (C), and combination of hot water dipping (40⁰C for 20 minutes) and irradiation at a 25 Gy (D). The samples were stored at room temperature. Evaluation on physical and chemical properties of the samples was done daily up to 10 days' storage. Parameters observed were texture, moisture and fat contents, percentage of weight loss, percentage of mature fruit, and subjective organoleptic evaluation. It was found that treated samples with and without combination treatment were still in good condition until 10 days of storage. It could be concluded that dipping in hot water, either alone or in combination with irradiation at a dose of 25 Gy could extend the shelf-life of fresh avocado up to 10 days at room temperature compared to only 5 days of the control. (author). 2 figs, 8 refs

[en] A silver-coated copper powder with an added transition Sn layer is obtained by electroless plating, and the prepared composite powder is heat-treated under a protective atmosphere to form a transition layer by diffusion between metal atoms for improved powder properties. The effect of the transition layer on the morphology, adhesion and oxidation resistance of the copper-coated copper powder is studied. The results show that the Cu/Sn/Ag composite powder exhibits excellent plating adhesion and oxidation resistance performance when the content of the intermediate layer is 10% of Sn. (paper)

[en] The strength and toughness of the heat-treated and tempered C-Mn are studied. Two types of heat-treatment have been carried out with the specimens in an argon gas. The variation in the fracture surfaces of the heat-treated and tempered specimens with impact test temperature is discussed also

[en] Published in summary form only

[en] A method is disclosed for heat treating an age-hardenable iron-nickelchromium alloy to obtain a morphology of the gamma-double prime phase enveloping the gamma-prime phase, the alloy consisting essentially of about 40 to 50% nickel, 7.5 to 14% chromium, 1.5 to 4% niobium, 0.3 to 0.75% silicon, 1 to 3% titanium, 0.1 to 5% aluminum, 0.02 to 1% carbon, 0.002 to 0.0015% boron and the remain substantially all iron. To obtain optimal results, the alloy is cold-worked 20 to 60% followed by heating at 1050⁰C. For 1/2 hour with an air-cool plus heating at 800⁰C. For 2 hours with a furnace cool to 625⁰C. The alloy is then held at 625⁰C. For 12 hours, followed by an air-cool

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