-Introduction. Vietnam is among the world's top 20 mango producing countries. In this country, the 'cat Hoa loc' variety is predominant, with 17 692 ha under cultivation with an annual production of 58 471 t; it is considered to be the best mango variety in the Mekong delta. Ripening of the fruit is typically expressed by a skin colour change from green to bright yellow. This variety is highly prized by local and foreign consumers, but subject to different disorders, especially fruit fly infestations. Heat treatment is a safe alternative to chemical treatments. It can impair mould development and control fruit infestation by destroying fruit fly eggs and larvae. It may have a greater or lesser effect on fruit physiology. If the treatment temperature and duration are incorrectly handled, skin burns may result and the internal quality of the fruit may be affected. Materials and methods. 'Cat Hoa loc' mangoes at the commercially mature stage were subjected to hot air treatment (47°C and 90% RH) of different durations [(0, 20, 40, 60, 90, 120 and 180) min from the fruit core attaining the temperature]. After treatment, the fruits were stored at 25°C and quality parameters evaluated (weight loss, peel and flesh colour, percentages of fruit with burns and rots, burn index, ripening percentage, firmness, TSS, TA, vitamin C content, pH, reducing and total sugars, and taste test). Results and discussion. For the 'cat Hoa loc' variety, heat treatment accelerated ripening of the fruit in the initial storage period and colour changes occurred more quickly. However, after 7 days' storage, the difference in Hue value between the treated and control fruits disappeared. Hot air treatment at 47°C of different durations [(20 to180) min] did not affect the internal coloration changes of 'cat Hoa loc' mangoes, but did affect the flesh firmness. We found that, after 3 d, hot air treatment at 47°C led to significantly faster weight loss than control fruits but this difference disappeared after 7 d. Total sugar content was not affected by the treatment, but titratable acidity decreased more quickly in treated fruits. Vietnam / Mangifera indica / fruits / postharvest control / heat treatment / qualityEffets du traitement thermique sur la qualité post-récolte de mangues 'cat Hoa loc'.Résumé -Introduction. Le Vietnam est parmi les 20 premiers pays producteurs de mangues au monde. Dans ce pays, la variété 'cat Hoa loc' est prédominante (17 692 ha cultivés et production annuelle de 58 471 t) ; elle est considérée comme la meilleure variété de mangue dans le delta du Mékong. La maturation du fruit s'exprime généralement par un changement de couleur de la peau qui vire du vert au jaune vif. Cette variété est très appréciée par les consommateurs locaux et étrangers, mais elle est sujette à divers troubles, notamment à des infestations par la mouche des fruits. Le traitement thermique est une bonne alternative aux traitements chimiques. Il peut altérer le développement des moisissures et contrôler l'infestation des fruits par la des...

Stainless steel (SS304) is a widely used material in underwater nuclear applications due to its superior corrosion resistance and high strength. Along with these superior properties, the application demands neutron absorption and high wear resistance under dynamic operations. The ceramic reinforcements help to enhance these properties of metal alloy with a suitable composite design. The present work deals with the development of high wear-resistant and radiation (nuclear) tolerant boron carbide (B4C)–SS 304 composite material. SS304 metal matrix with 0–5 vol% of B4C ceramic reinforcement is produced by powder metallurgy technique. The presence of reinforcement was confirmed with X-ray diffraction analysis. Properties such as density, hardness, and water absorption are measured. A pin-on-disc tribology study is conducted to evaluate the coefficient of friction and wear of developed compositions at a sliding distance of 200 m, contact load of 10 N, and sliding speed of 1 and 5 m/s under dry lubrication conditions. The lowest density of 2.96 g/cc was noted for 15% B4C-reinforced composite as compared to the density of SS304 metal matrix (5.71 g/cc). The water absorption capacity of the composite was increased with percentage reinforcement, and it was found 62% higher than the unreinforced matrix. The hardness of composite increases with B4C particle reinforcement and maximum microhardness of 153 HV was measured for 15 vol% reinforced composites. Wear and coefficient of friction decrease with an increase in the percentage of B4C particles. At 15 vol% of B4C in the composite, lowest wear (1.91 mm3@1 m/s and 2.51 mm3@5 m/s) and COF (0.021@1 m/s and 0.042@5 m/s) were observed. This suggests that the developed composite can be effectively used in low-pressure–high-speed nuclear applications.

The main purpose of this article is to establish a susceptibility zonation map of the landslides and debris flows in Phin Ngan commune, Bat Xat district, Lao Cai province on a large scale using statistical methods and machine learning combined with the FlowR model. First, the five Landslide Susceptibility Index (LSI) maps were established from two statistical models (Logistic Regression - LR, Discriminant Analysis – DA) and three machine learning models (Bayesian Network – BN, Artificial Neural Network – ANN, Support Vector Machine – SVM) were generated based on seven maps of landslide conditioning factors (slope, curvature, stream power index-SPI, topographic wetness index-TWI, sediment transportation index-STI, land use/land cover and weathering crust). Next, the five LSI maps will be evaluated for performance with the value of Area Under the Curve (AUC) according to the Receiver Operating Characteristic (ROC) curve. After that, a susceptibility map of debris flow established with FlowR software was combined with the five LSI maps created from five statistical and machine learning methods to generate a susceptibility zonation map of landslides and debris flows in the study area. The area percentage of the locations with ​​landslides and debris flows located in the zones of susceptibility (very low, low, medium, high, very high), which were created from five combined methods: BN-FlowR, LR-FlowR, DA-FlowR, ANN-FlowR, and SVM-FlowR, were compared and evaluated. The results indicate that the integrated models have given outputs with good forecasting ability. They are also very useful in land-use planning as well as the prevention and mitigation of risks due to landslides and debris flows in the research area and other similar mountainous areas.