Formal Modeling and Verification for MVB

Multifunction Vehicle Bus (MVB) is a critical component in the Train Communication Network (TCN), which is widely used in most of the modern train techniques of the transportation system. How to ensure security of MVB has become an important issue. Traditional testing could not ensure the system correctness. The MVB system modeling and verification are concerned in this paper. Petri Net and model checking methods are used to verify the MVB system. A Hierarchy Colored Petri Net (HCPN) approach is presented to model and simulate the Master Transfer protocol of MVB. Synchronous and asynchronous methods are proposed to describe the entities and communication environment. Automata model of the Master Transfer protocol is designed. Based on our model checking platform M3C, the Master Transfer protocol of the MVB is verified and some system logic critical errors are found. Experimental results show the efficiency of our methods

Influence of Microstructure on Chip Formation when Broaching Ferritic-Pearlitic Steels

Broaching is a specific process characterized by relatively low cutting speeds and uncut chip thicknesses. The latter is in the range of 0.1 to 0.25 mm in the roughing section of the tool but can decrease down to 0.0015 mm in the finishing one. This induces drastically different cutting behaviours compared to macroscale processes such as turning. The question of the scale effects in such conditions is thus clearly raising and especially the size and distribution of the microstructure. This paper proposes an investigation to assess the importance of the material heterogeneities on chip formation when broaching ferritic-pearlitic steels

High-throughput bioprinting of the nasal epithelium using patient-derived nasal epithelial cells.

Progenitor human nasal epithelial cells (hNECs) are an essential cell source for the reconstruction of the respiratory pseudostratified columnar epithelium composed of multiple cell types in the context of infection studies and disease modeling. Hitherto, manual seeding has been the dominant method for creating nasal epithelial tissue models through biofabrication. However, this approach has limitations in terms of achieving the intricate three-dimensional (3D) structure of the natural nasal epithelium. 3D bioprinting has been utilized to reconstruct various epithelial tissue models, such as cutaneous, intestinal, alveolar, and bronchial epithelium, but there has been no attempt to use of 3D bioprinting technologies for reconstruction of the nasal epithelium. In this study, for the first time, we demonstrate the reconstruction of the nasal epithelium with the use of primary hNECs deposited on Transwell inserts via droplet-based bioprinting (DBB), which enabled high-throughput fabrication of the nasal epithelium in Transwell inserts of 24-well plates. DBB of progenitor hNECs ranging from one-tenth to one-half of the cell seeding density employed during the conventional cell seeding approach enabled a high degree of differentiation with the presence of cilia and tight-junctions over a 4 weeks air-liquid interface culture. Single cell RNA sequencing of these cultures identified five major epithelial cells populations, including basal, suprabasal, goblet, club, and ciliated cells. These cultures recapitulated the pseudostratified columnar epithelial architecture present in the native nasal epithelium and were permissive to respiratory virus infection. These results denote the potential of 3D bioprinting for high-throughput fabrication of nasal epithelial tissue models not only for infection studies but also for other purposes, such as disease modeling, immunological studies, and drug screening

Is PM1 similar to PM2.5? : a new insight into the association of PM1 and PM2.5 with children's lung function

Experimental data suggests that PM1 is more toxic than PM2.5 although the epidemiologic evidence suggests that the health associations are similar. However, few objective exposure data are available to compare the associations of PM1 and PM2.5 with children lung function. Our objectives are a) to evaluate associations between long-term exposure to PM1, PM2.5 and children’s lung function, and b) to compare the associations between PM1 and PM2.5. From 2012 to 2013, we enrolled 6,740 children (7-14 years), randomly recruited from primary and middle schools located in seven cities in northeast China. We measured lung function including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), and maximal mid-expiratory flow (MMEF) utilizing two portable electronic spirometers. We dichotomized continuous lung function measures according the expected values for gender and age. The spatial resolution at which PM1 and PM2.5 estimated were estimated using a machine learning method and the temporal average concentrations were averaged from 2009 to 2012. A multilevel regression model was used to estimate the associations of PM1, PM2.5 exposure and lung function measures, adjusted for confounding factors. Associations with lower lung function were consistently larger for PM1 than for PM2.5. Adjusted odds ratios (OR) per interquartile range greater PM1 ranged from 1.53 for MMEF (95% confidence interval [CI]: 1.20-1.96) to 2.14 for FEV1 (95% CI: 1.66-2.76) and ORs for PM2.5 ranged from 1.36 for MMEF (95%CI: 1.12–1.66) to 1.82 for FEV1 (95%CI: 1.49-2.22), respectively. PM1 and PM2.5 had

Towards Low Carbon: A Lightweight Design of Automotive Brake Hub

Carbon peaking and carbon neutrality have become important considerations in today’s manufacturing industry. Vehicle lightweight design can reduce carbon emissions and it is an important means to achieve carbon peak and carbon neutrality. In this study, the lightweight design method of automotive brake hub towards low carbon and the calculation method of low-carbon benefit are presented. A brake hub is the core of a drum brake, working together with a friction plate and brake shoe to complete the braking process. The requirements for the safety performance of brake hub are becoming increasingly more stringent in order to improve the stability and safety of the braking process. The brake hub ZD02-151122A manufactured by Anhui Axle Co., Ltd.(Suzhou, China), was used as the research object. The lightweight optimization of the brake hub was designed under the lightweight drive to reduce the shape variables and stress values of the brake hub and to reduce the mass. The proposed optimization scheme changed the chamfering to 45 × 45 and increased the number of bolt holes to eight. Compared with the original brake hub, the maximum strain, maximum stress value, stress concentration coefficient, and mass were reduced by 15.38%, 17.66%, 1.50%, and 17.40%, respectively, which achieved the specified optimization goal of improving mechanical properties and reducing mass. Towards low carbon, the reduction in carbon emissions from the optimized brake hub manufacturer and the vehicle during operation was calculated. For Anhui Axle Co., Ltd., the carbon emission can be reduced by 4.21 × 106 kg per year. Moreover, vehicle exhaust emissions can be reduced by 8.76 × 108 kg if all trucks produced by a medium-sized vehicle assembly company are driven on the road until being scrapped. This study serves as a reference for design optimization and low-carbon benefit analysis of other major automotive components

Towards Low Carbon: A Lightweight Design of Automotive Brake Hub

Carbon peaking and carbon neutrality have become important considerations in today’s manufacturing industry. Vehicle lightweight design can reduce carbon emissions and it is an important means to achieve carbon peak and carbon neutrality. In this study, the lightweight design method of automotive brake hub towards low carbon and the calculation method of low-carbon benefit are presented. A brake hub is the core of a drum brake, working together with a friction plate and brake shoe to complete the braking process. The requirements for the safety performance of brake hub are becoming increasingly more stringent in order to improve the stability and safety of the braking process. The brake hub ZD02-151122A manufactured by Anhui Axle Co., Ltd.(Suzhou, China), was used as the research object. The lightweight optimization of the brake hub was designed under the lightweight drive to reduce the shape variables and stress values of the brake hub and to reduce the mass. The proposed optimization scheme changed the chamfering to 45 × 45 and increased the number of bolt holes to eight. Compared with the original brake hub, the maximum strain, maximum stress value, stress concentration coefficient, and mass were reduced by 15.38%, 17.66%, 1.50%, and 17.40%, respectively, which achieved the specified optimization goal of improving mechanical properties and reducing mass. Towards low carbon, the reduction in carbon emissions from the optimized brake hub manufacturer and the vehicle during operation was calculated. For Anhui Axle Co., Ltd., the carbon emission can be reduced by 4.21 × 106 kg per year. Moreover, vehicle exhaust emissions can be reduced by 8.76 × 108 kg if all trucks produced by a medium-sized vehicle assembly company are driven on the road until being scrapped. This study serves as a reference for design optimization and low-carbon benefit analysis of other major automotive components

A new species of the genus Acanthosaura (Squamata, Agamidae) from Yunnan, China, with comments on its conservation status

A new species of Acanthosaura from Yunnan, China, is described based on morphological and genetic data. The new species can be separated from all other species of the genus by having a different shape of the black eye patch, a different coloration of the postorbital and occipital spines and nuchal crest, and a different color of the gular pouch. Genetically, uncorrected sequence divergences of COI between the new species and investigated congeners ranged from 16.12% to 24.11%. The conservation status of the new species is also discussed