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The microbial community is one of the most important factors in shaping the characteristics of fermented food. Nuodeng ham, traditionally produced and subjected to 1-4 years of fermentation, is a dry fermented food product with cultural and economic significance to locals in southwestern China. In this study, we aimed to characterize the microbiota and physicochemical profiles of Nuodeng ham across different stages of fermentation. Ham samples from each of the four years were analyzed by sequencing bacterial 16S rRNA gene and fungal internal transcribed spacer sequence, in order to characterize the diversity and composition of their microflora. A total of 2,679,483 bacterial and 2,983,234 fungal sequences of high quality were obtained and assigned to 514 and 57 genera, respectively. Among these microbes, Staphylococcus and Candida were the most abundant genera observed in the ham samples, though samples from different years showed differences in their microbial abundance. Results of physicochemical properties (pH, water, amino acid, NaCl, nitrate and nitrite contents, and the composition of volatile compounds) revealed differences among the ham samples in the composition of volatile compounds, especially in the third year samples, in which no nitrite was detected. These results suggest that the structure and diversity of microbial communities significantly differed across different stages of fermentation. Moreover, the third year hams exhibits a unique and balanced microbial community, which might contribute to the special flavor in the green and safe food products. Thus, our study lends insights into the production of high quality Nuodeng ham.

Water inside the micropores has a tremendous influence on the mechanical properties and damage patterns of rocks. To investigate the effects of different moisture contents on the cracking behavior of sandstone under different compression conditions, four groups of sandstone samples with moisture contents of 1.00%, 2.50%, 3.50% and 4.50% were used for uniaxial compression and cyclic loading-unloading experiments. The results show that the compressive strength and elastic modulus decrease with the increase of moisture content. The ultimate failure patterns for samples are all shear failure modes with different dip angles. In the unloading experiments, the dissipated energy and residual strain decreases with the increase of moisture content during the unloading stage with low stress and increases obviously during the unloading stage with high stress.

By defining the degree of dominance between two sets with respect to a certain criterion, a new alpha-dominance relation is proposed in this paper. And then a rough set approach based on this relation in disjunctive set-valued ordered information systems is presented. After that, a ranking method for all objects is introduced to the disjunctive set-valued ordered information systems, and a numerical example is illustrated to demonstrate the validity of this ranking method.

This study has investigated the particle transmission efficiency through the nozzle of the API AerosizerTM numerically. Two-dimensional flow field in the nozzle was first simulated. Particle trajectories for both liquid and solid particles were then calculated to obtain the particle transmission efficiency under various conditions. This study shows that particle aerodynamic diameter, particle materials, particle density and laser beam diameter influence the transmission efficiency. The transmission efficiency is found to increase with increasing particle diameter when the particle aerodynamic diameter is less than several micrometers. The efficiency for liquid particles drops significantly when particle aerodynamic diameter increases from several micrometers because of particle impaction loss in the nozzle. For solid particles, the relationship of the efficiency with particle diameter is found to be more complicated. For particles less than several micrometers in aerodynamic diameter, solid particles behave similarly to the liquid particles. However, as particles are greater than several micrometers, the effect of solid particle bounce is to increase the transmission efficiency with increasing aerodynamic diameter until particles become large enough so that plastic deformation occurs in the particles. Then the transmission efficiency will decrease with increasing particle aerodynamic diameter.