Marine diesel units will produce certain vibration and noise at work, which will affect the normal operation of machinery and crew’s physical and mental health. It is a common solution to equip diesel units with vibration isolators, so it is very necessary to optimize the design of vibration isolators. Based on diesel engine set with double layer metal rubber vibration isolator, for example, to establish the geometric model of the vibration isolator with Solidworks, and importing it into the finite element software called ANSYS Workbench to make simulation calculation, get the vibration isolator in forward loading, reverse load and radial load displacement nephogram under three working conditions and stress nephogram, get the maximum double metal rubber vibration isolator deformation, the maximum stress value and the location of maximum stress. The results show that the maximum stress of the double layer metal rubber isolator is less than the yield limit of the material, which meets the work requirements. The stress concentration is easy to occur in the center of the bottom base of the vibration isolator, that is, fatigue failure is easy to occur. Under the condition of radial loading, the maximum deformation of the case is large. The maximum deformation and stress of the improved case are significantly reduced, which is of guiding significance to the optimal design of the vibration isolator.
Recent developments and advances in Ti/TiO2-NTs/PbO2 electrodes:A general Review of their controllable preparation and application in wastwater treatment
Ti/TiO2-NTs(nanotubes)/PbO2 is a new composite electrode material,which has been considered as an optimal electrode material for electrochemical oxidation of organic contaminants in the aquatic environmentthat due to its its good physical and chemical properties,such as good electrocatalytic activity, high oxygen evolution potential, corrosion resistance, good stability, environmental friendliness and simple preparation. The fundamental research and practical application of Ti/ TiO2-NTs(nanotubes)/PbO2 electrodes in the mineralization of organic pollutants have been well developed up to now. So this paper mainly reviews the preparation methods of Ti/TiO2-NTs/ PbO2 electrodes and the structural characterization methods of electrode materials first. And then, the basic principle of electrocatalytic oxidation will be introduced in detail and the application of this electrodes in water treatment is going to be summarized systematically. Further, we also proposed the existing problems in recent research and the potential development direction of electrocatalytic water treatment technology in the future, which could provide reference for the follow-up research.
In Electrodeionization is used in various water treatments due to its low energy consumption, high efficiency and cleanliness. The application of EDI in various water treatments, including heavy metal wastewater, ammonia nitrogen wastewater, salty wastewater, and organic wastewater purification, are reviewed. Ion exchange resins and membranes are important factors influencing the performance of EDI. The research progress on ion exchange resins and membranes in EDI is described, focusing on the solution to the membrane fouling problem in EDI process. Reducing and preventing membrane pollution in EDI is the focus of current research. Solving membrane pollution problem will greatly promote the development and application of EDI.
Nanometer zero-valent iron (nZVI) technology is one of the hotspot in environmental science, according to its huge surface area and high reactivity for the heavy metals, halogenated organic matter. However, as a result of a single nZVI problems easy to reunite and oxidized effect of nZVI reactivity, reduction of pollutant removal effect, the modification of nanometer zero-valent iron is a hotspot of nZVI technology this paper mainly discusses the conventional physical and chemical preparation methods of nanometer zero-valent iron and modified nano zero-valent iron technology are summarized, the future research emphases of nZVI technology are prospected.
Perception of Airport security and safety of international passengers a study Murtala Mohammed International Airport in Nigeria
There had been an increasing security and safety concerns at international terminals since the September 11 incident in the US. In this regards, most related studies seems to be biased towards the developed economics preparedness to enhance and avert possible disaster encountered at the US. However, with the increasing threat being posed on a daily basis on African international terminal especially the Nigerian airport with the rise of Boko Haram and other emerging insurgents threats. This study seeks to examine the perception of international passenger on the safety and security of the Nigerian airport terminal. The methodology involves both the qualitative and the quantitative methods. The data is analysed with descriptive and inferential statistical analytical techniques. The study reveals there is a significant relationship between airport passenger perception of safety and enhanced security level at the airport. Also the passenger nationality status also influences the level of security procedures at the Murtala Mohammed International airport.
Protein-protein interactions (PPIs) and protein complexes formed by interactions are the main accomplishers of various functions of cells. As an important component of biological networks, protein interaction plays an important role in determining life processes such as signal transduction in cells. Although the experimental methods for studying protein interactions are endless, there are still many shortcomings and gaps in the research on the interaction of precisely regulated protein molecules. LOV (Light Oxygen Voltage) is a light-sensitive protein domain originally discovered in the photo of plants for receiving blue light stimulation, transmitting signals, and causing a series of reactions in plants. The LOV domain belongs to a member of the PAS (Per-Arnt-Sim) superfamily and contains two subunits, LOV1 and LOV2. LOV2 is thought to cause a conformational change after receiving light stimulation, primarily responsible for activating the kinase domain. It plays an important role in intracellular signal transduction. In view of the light control and sensitivity of LOV2, which can be used as a research tool in protein interaction processes, the mechanism of action and structural advantages of signal transduction in LOV2 domain in protein interactions are reviewed.
Analysis of commercial automobile insurance operating efficiency and Its influence factors of Chinese property insurance companies -An empirical analysis based on SBM-DEA method and Tobit model
This paper selects the operation data of commercial car insurance of 25 companies in 2012-2016, and calculates the efficiency of commercial car insurance by using SBM-DEA model, also analyzes the main factors affecting the efficiency of commercial car insurance operation by using the Tobit panel data estimation model. The main conclusions are as follows: 1. The overall efficiency value of the commercial insurance company is low, and only 2 of the 25 property insurance companies tested reached the effective frontier, there is still a large space for improvement, the redundancy of low efficiency companies is more serious; In the past three years, the technical efficiency value has remained stable and the upward trend is not obvious. 2. Commercial car insurance premium income share, market share, cost rate, company asset size, all have different degrees of impact on the efficiency value of commercial car insurance.
European diplomacy was in a dominant position after the loss of Soviet influence in the eastern European countries. The Yugoslav crisis was the first challenge for the European Community that could not stop the conflict in the areas of the former Yugoslavia. It did not appear determined in the initial positions of the Yugoslav crisis by attempting to maintain the Yugoslav federation, at a time when it was impossible for the coming of leaders seeking independence from the such federation. The efforts of European diplomats at the London Conference, The Hague, and then onwards to that of Geneva failed to stop the expansion of the conflict towards Kosovo. Where peace was established only when at the same time diplomacy was combined with NATO air force.
In this paper, a DFT- based OFDMA with phase modulation (DFT-OFDMA-PM) system is proposed. The proposed system exploits the advantages of PM, the constant envelope (CE) signal, and the ability to improve the diversity of multipath channels. The performance of the proposed system in terms of bit error rate (BER) is studied and investigated using simulation. An investigation of the proposed system, the DFT-OFDMA-PM, results is carried and compared to the recently proposed DCT-OFDMA-PM system and the conventional systems without PM. Moreover, the key parameter, the modulation index, which affects the performance of the PM systems, is also studied and the optimum value is chosen via simulation. The simulation results for the proposed system show the effectiveness of the proposed system for broadband communications.
Modeling a Fault Tolerant Control Mechanism for Cloud e-marketplaces using Raft Consensus Protocol (RCP)
The evolution of marketplaces started from the traditional marketplace, the internet marketplace, the web service marketplace, the grid marketplace, before moving to cloud e-marketplace. The need to have rapid access to various service by different customers brought about cloud e-marketplaces. The goal of the cloud e-marketplace is to attract the biggest possible number of buyers while ensuring a reduced waiting time for customers and maximized profit for cloud service providers. Challenges like security, performance and fault tolerance are of great concern in the cloud market. While discussion on the issue of security and performance are ongoing, that of fault tolerance is yet to be fully addressed. Although some researchers have proposed the use of multiple servers in achieving the main idea of the cloud e-marketplace, different kinds of faults still affects the performance of cloud e-market. Balancing of providers’ cost and customers’ waiting time is still a major concern. Various techniques have been proposed in solving these problems. However, these techniques only work in a static environment where these servers can be faulty which may lead to long waiting time. We propose the use of Raft consensus protocol as our fault tolerant approach. We use the dynamic environment as against the already static approached already discussed in the literature. In the dynamic environment, two fault tolerant centers that are capable of surviving failure caused by server overload or congestion are used. These are primary and the reservoir centers. The Raft Consensus Protocol is used in both centers to coordinate the servers and make sure that each of the servers exist either as the leader, a candidate, or a as a follower. A waiting time counter algorithm is developed that directs customers request to the primary center when waiting time t