scholarly journals Experimental Research on Data Synchronous Acquisition Method of Subsidence Monitoring in Submarine Gas Hydrate Mining Area

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4319
Author(s):  
Jiawang Chen ◽  
Chen Cao ◽  
Yongqiang Ge ◽  
Huangchao Zhu ◽  
Chunying Xu ◽  
...  

The data synchronous acquisition is crucial to the seafloor subsidence monitoring system for gas hydrate mining areas based on microelectromechanical sensors (MEMS). Because the independent and high-precision time reference sources on land cannot be used on the seafloor, especially in the deep sea, a relative time synchronization method based on input/output (I/O) and controller area network (CAN) bus was proposed to realize the internal time synchronization of the system. To demonstrate the feasibility of the proposed method, tests including the deformation test of the MEMS sensor array under high pressure, synchronous accuracy test, and landslide and collapse simulation tests were carried out. The synchronization method was performed once every 24 h, and the time drift was reduced to 0.38 ms from more than 30 ms, demonstrating that method can achieve consistent internal time of the system. The method does not require additional hardware devices and has adjustable accuracy.

2020 ◽  
Vol 10 (24) ◽  
pp. 8873
Author(s):  
Hyeong Jun Kim ◽  
Uri Lee ◽  
Manho Kim ◽  
Suk Lee

Time-synchronization technology can provide a common notion of time among the participating nodes on a network. This is essential not only for protocol operation for time-critical services but also for the time stamp for information included in the message. Precise time information can be very crucial for such things as autonomous driving because there are various sensor measurements from multiple cameras, and radio detection and ranging (radar) and light detection and ranging (LiDAR) are used for perceiving the current situation via sensor fusion. A well-known synchronization method, IEEE 1588, denoted as the precision time protocol (PTP), can be used for various applications. For in-vehicle networks of autonomous cars, we have to consider that the network may be comprised of subnetworks based on different protocols such as controller area network (CAN) and Ethernet. However, implementing PTPs on such heterogeneous vehicle networks causes several problems. First, the PTP procedure must be modified to be implement on a CAN network. Second, to calculate the delay and offset for PTP, the processing delay that occurs during message conversion must be considered. In this paper, we propose a synchronization method for CAN–Ethernet networks to solve these problems. The performance of the proposed synchronization method is evaluated by experiments on a real CAN–Ethernet network.


2021 ◽  
Vol 11 (8) ◽  
pp. 3670
Author(s):  
Chih-Yu Chen ◽  
Yung-Chu Chang ◽  
Teh-Hua Tsai ◽  
Man-Hai Liu ◽  
Ying-Chien Chung

Research on gold nanoparticles (AuNPs) has often focused on their physical, chemical, and crystalline characteristics. Commercial AuNPs have been applied in the diverse fields of biomedicine, catalysis, photovoltaics, and sensing. In this study, we explored the various activities of AuNPs to widen their applicability. This paper presents a simple and rapid synthesis process of AuNPs with bacteria isolated from a gold mining area. We also investigated the optimization of reaction parameters for AuNP synthesis. The study results revealed that among the isolated strains, Bifidobacterium lactis and Escherichia coli demonstrated the highest capabilities of AuNP synthesis. The optimal pH values for AuNP synthesis by B. lactis (BLAuNPs) and E. coli (ECAuNPs) were 5.0 for 72 h of incubation and 8.0 for 24 h of incubation. The average particle sizes of ECAuNPs and BLAuNPs were 4.2 and 5.6 nm, respectively. Furthermore, these biogenic AuNPs were found to be stable with no aggregation after 3 months of storage. BLAuNPs and ECAuNPs exhibited high levels of antimicrobial, antioxidant, photocatalytic, and antityrosinase activity. Moreover, they were noncytotoxic to skin cells even at 100% melanin inhibitory concentrations. Considering the demonstrated multifunctional activities of AuNPs, BLAuNPs and ECAuNPs have promising potential for commercialization.


Author(s):  
Young Soo Do ◽  
Min Ho Kim ◽  
Jae Wook Jeon

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Wai Yi

The characteristics of strata, structures, magmatic rocks, lithology and mineralization in Dongtao mining area (Songwang area) of Bobai County, Guangxi were summarized. According to the geochemical anomalies of sediment in water system, and the main anomalies are explained and evaluated, combined with the geological characteristics of Dongtao and other mining areas, the prospecting prediction of favorable areas is carried out, and it is considered that there is a good prospect of prospecting.


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