Introduction to Supply Chain Security and Mutual Trust Research Minitrack

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Coupling vibration analysis of auger drilling system

In the process of drilling coal, the kinematics of drill-rod is quite complicated. The drill-rod not only vibrates in longitudinal, transverse and torsional direction, but also random impacts and contacts coal wall. Considering the drilling load of drill-bit and coal, contact impact of the drill-rod and coal wall, the drill-rods are dispersed into a number of finite elements. At the same time, the nonlinear dynamic model of drill-rod system coupling longitudinal, transverse and torsional vibration is set up. The simulations of the dynamic model are researched under the conditions of different hardness coal (2.7, 3.7, 4.65). In order to decrease the vibration of auger drill, the stabilizer is added onto the drilling mechanism. And the underground experiments are done at 2404 working face of Xie-Zhang Coal Mine in Shan-Dong Province of China. The results indicate that the transverse vibration radius, the longitudinal vibration frequency and amplitude all decrease with the rock hardness. The maximum transverse vibration radius shows an exponential relation with the drilling depth under the condition of the same rock. Under the same condition, the drilling depth of auger drill with stabilizer is 1.39 times that with no stabilizer, and the drilling pressure decreases about 2/3

Regulation of Biosurfactant Production by Quorum Sensing in Pseudomonas fluorescens 5064, the Cause of Broccoli Head Rot Disease

Broccoli head rot is a destructive disease found in most broccoli production areas. The main pathogen is the bacterium Pseudomonas fluorescens. P. fluorescens 5064, which was first isolated from an infected broccoli head in SE Scotland, produces biosurfactants that are important for bacterial establishment on the plant surface prior to causing disease in broccoli. Preliminary experiments performed in this study showed that biosurfactant production in P. fluorescens 5064 was cell density dependent, which is a typical characteristic of the quorum sensing mechanism. Quorum sensing is a bacterial communication mechanism, which controls a number of key processes in growth, reproduction and virulence via signalling molecules (quorum sensing signal) in many gram-negative bacteria. One aim of this study was to determine if biosurfactant production in P. fluorescens 5064 is controlled via quorum sensing. To do this, 35 surfactant-minus Tn5 mutants of P. fluorescens 5064 were screened for their abilities to produce a quorum sensing signal. Six of these biosurfactant-deficient mutants showed a large reduction in quorum sensing signal production. In one mutant 6423, which contains a single Tn5 insertion, the production of the quorum sensing signal was almost eliminated. Addition of quorum sensing signal, either synthetic or extracted from wild type P. fluorescens 5064, was able to restore biosurfactant production in mutant 6423. This strongly suggests that quorum sensing regulates biosurfactant production in P. fluorescens 5064. Attempts were made to clone and sequence the Tn5 disrupted gene in mutant 6423, but the identity of the gene remains inconclusive. The quorum sensing signal in wild type P. fluorescens 5064 was identified in this study by High Pressure Liquid Chromatography and Mass Spectrometry as N-3-hydroxyoctanoyl-homoserine lactone, which has been shown by other researchers to be present in P. fluorescens strain 2-79, but not in the strains F113, 7-14 and NCIMB 10586. The discovery that biosurfactant production in P. fluorescens 5064 is regulated by quorum sensing opens up a possibility for novel control of broccoli head rot. Although only the control of biosurfactant production by quorum sensing was examined in this study, it is possible that other virulence factors, such as pectic enzyme production, are also controlled by quorum sensing as in other pathogenic bacteria. By blocking the quorum sensing system, the pathogenic P. fluorescens that use this mechanism to control virulence could potentially be rendered avirulent. In greenhouse pathogenicity tests, a quorum sensing signal-degrading bacterium, Bacillus sp. A24, was evaluated for biocontrol of head rot disease caused by P. fluorescens 5064 on broccoli. However, the Bacillus sp. A24 showed only limited control effects, despite its strong quorum sensing signal-degrading ability towards the pathogen in vitro. A subsequent test proved that Bacillus sp. A24 is a surfactant producer itself and this could explain its ineffectiveness in disease control. When screening the quorum sensing signals of the 35 biosurfactant mutants, mutant 6418 was found to produce a potent antibiotic-like compound. This was identified by thin-layer chromatography as pyrrolnitrin. Unlike wild-type P. fluorescens 5064, mutant 6418 has lost its ability to produce virulence factors and is thus non-pathogenic. It was therefore of interest to determine if mutant 6418 could be used as a biocontrol agent to control broccoli head rot disease. In greenhouse pathogenicity tests, mutant 6418 significantly reduced disease by 41 %. The practical application of this research to bacterial disease control – via the manipulation of quorum sensing to inhibit virulence gene expression – is discussed

Research on homogeneous deformation of electromagnetic incremental tube bulging

The electromagnetic incremental forming (EMIF) method is used for tube forming process. Suitable 2D FE models are designed to predict the forming process with a moving coil. In comparison with experimental values, simulation method can obtain accurate results. Then, effect factors named overlapping ration of adjacent discharge positions, discharge voltage, forming sequence and die dimension on tube homogeneous deformation are discussed. The result demonstrates that it is feasible to produce long-straight wall tubes using a small coil by electromagnetic incremental tube bulging

Deep Drawing of Cylindrical Cup Using Incremental Electromagnetic Assisted Stamping with Radial Magnetic Pressure

AbstractA new forming method named incremental electromagnetic assisted stamping with radial magnetic pressure is proposed to draw a deep cylindrical cup. The method combines with traditional stamping, electromagnetic sheet forming and electromagnetic launch technology. Three types of discharge coils are imbedded in die and blank holder, respectively. The 3D finite element model is set up to predict the complex deformation process. The forming process and principle of the new method are discussed. The values of material flow, stress and thickness in different forming processes are compared. In comparison with traditional stamping, incremental electromagnetic assisted stamping with radial magnetic pressure can significantly increase the value of material at sheet end flow inward, decrease the tensile stress and thickness reduction at the easily broken position, and obtain uniform stress distribution. Therefore, deeper cylindrical cup could be manufactured by incremental electromagnetic assisted stamping with radial magnetic pressure

Interference model of conical pick in cutting process

The load on conical pick is affected by many factors such as pick geometry and installation angle. In order to decrease the wear and vibration of pick in the cutting process by choosing proper impact angle, the interference mathematical models of straight and revolving cutting were established according to coal cutting theory. Based on this, coal cutting experiment was carried out with different impact angles β, different head face radii of pick body R and different cutting depths d to verify the mathematical model. The results indicate that the picks cutting into coal with a certain installed angle are prone to interfere with coal in the cutting progress. There is a crsitical impact angle, and it is different under different cutting conditions. The critical impact angle decreases with the head face radius of pick body R and cutting depth d. On the condition of given pick geometry and movement parameters, the cutting force of picks or cutting torque of cutting header decreases with the impact angle. When the impact angle of the pick is larger than the critical angle, the load on pick will increase prominently

Fault diagnosis of pump valve spring based on improved singularity analysis

The fracture of pump valve springs is another typical fault of emulsion pump with high pressure and large discharge, which greatly influences the volumetric efficiency of emulsion pump. The fault diagnosis on pump valve springs of emulsion pump was analyzed based on the singularity analysis of continuous wavelet transform. The improved method for Lipschitz index was presented with better robustness and efficiency based on the Least Square Method. The criterion for the fracture of pump valve was confirmed. Diagnostic results indicate that it is accurate and effective of the improved method to locate the singularity of signals, identify the moment when the valve disc impacts on base or lift limiter and judge the fault diagnosis of pump valve

Application of Blockchain and Internet of Things to Ensure Tamper-Proof Data Availability for Food Safety

Food supply chain plays a vital role in human health and food prices. Food supply chain inefficiencies in terms of unfair competition and lack of regulations directly affect the quality of human life and increase food safety risks. This work merges Hyperledger Fabric, an enterprise-ready blockchain platform with existing conventional infrastructure, to trace a food package from farm to fork using an identity unique for each food package while keeping it uncomplicated. It keeps the records of business transactions that are secured and accessible to stakeholders according to the agreed set of policies and rules without involving any centralized authority. This paper focuses on exploring and building an uncomplicated, low-cost solution to quickly link the existing food industry at different geographical locations in a chain to track and trace the food in the market.Comment: Journal of Food Quality, 202

Strengthen the application research of big data in food safety

Food safety is essential to national economy and people's livelihood. A good food safety system is extremely important for maintaining social stability and providing scientific data for government decision. Big data provides a new approach to food safety. Through the integration of the data in the whole industrial chain, it will greatly improve the data analysis ability and help in discovering the potential valuable information. It could provide scientific decision-making suggestions for regulators, producers and consumers. It will provide a solution for timely warning of food safety incidents, the accurate traceability and accountability of food products. This paper will briefly introduce some existing big data platforms in food safety area. Then, it will discuss the challenges such as multi-sources data analysis, visualization and market mechanism. At the end of this paper, the future development trend of big data in food safety area is discussed