Applying switching and multiple access model for reducing packet loss and network overheads in watm

As an effectual simple wireless equivalent created in the telecommunications (telephone) industry, Wireless Asynchronous Transfer Mode (WATM) is utilized to stream unified traffics like video, data, and voice data. In the asynchronous data transfer mode, voice data transfer a packet with the same medium, and data share the networks and burst data. Effective WATM data transmission requires an extensive array of designs, techniques used for control, and simulation methodologies. The congestion of the network is among the key challenges that lower the entire WATM performance during this procedure, in addition to the delay in cell and the overload of traffic. The congestions cause cell loss, and it requires expensive switches compared to the LAN. Consequently, in this current study, the application of an effectual switching model together with a control mechanism that possesses multiple accesses is employed. The multiple access process and switching model are utilized to establish an effective data sharing process with minimum complexity. The switching model uses the synchronous inputs and output ports with buffering to ensure the data sharing process. The traffic in the network is decreased, and the loss of packets in the cells is efficiently kept to a minimum by the proposed technique. The system being discussed is employed through the utilization of software employed using OPNET 10.5 simulation, with the valuation of the WATM along with the investigational outcomes accordingly. The system's efficiency is assessed by throughput, latency, cell loss probability value (CLP), overhead network, and packet loss. Thus, the system ensures the minimum packet loss (0.1 %) and high data transmission rate (96.6 %)

Analysis of Metal Transfer and Weld Forming Characteristics in Triple-wire Gas Indirect Arc Welding

Triple-wire gas indirect arc welding (TW-GIA) has the advantages of low heat input and high deposition rate. However, the simultaneous melting of triple wires makes the metal transfer mode complicated. The unknown of the metal transfer mode restricts the development of this technology. In this paper, high-speed camera systems and electrical signal acquisition sensors were used to explore the TW-GIA metal transfer mode. The static force model and the arc conductive channel model were used to discuss the droplet force and energy conversion characteristics respectively. Results showed that the TW-GIA metal transfer modes can be divided into: short-circuit transfer (SCT), main wire projected transfer + side wire globular transfer (PGT), main wire streaming transfer + side wire projected transfer (SPT) and main wire streaming transfer + side wire streaming transfer (SST). Moreover, the process parameter ranges corresponding to the four modes were summarized. Due to the stable arc and the uniform metal transfer process, SPT and SST can form desirable weld seam. The gravity and z-axis components of electromagnetic force are the main forces that promote metal transfer. The x-axis and y-axis components of the electromagnetic force deviate the metal transfer path from the arc coverage. Due to the change of arc conductive channel, the energy transferred from TW-GIA to the base metal is less than that of GMAW, showing the advantages of small welding deformation, narrow heat affected zone and grain refinement.

Strength analysis and method research of a light truck powertrain mounting system

This paper presents an integral strength checking method to solve the problem that the step-by-step strength checking method cannot check the strength of metal parts in the rubber mounting system of light truck powertrain. By establishing an integral finite element model including powertrain and rubber mount system and considering the rubber bearing and force transfer mode, the motion coordination and overall analysis of mount system and powertrain are realized. The calculation results show that the proposed method can easily and accurately complete the strength check of metal parts of the mounting system, which provides a reference for the structural design of the mounting system.

Flow and heat transfer near a cylinders row

The paper aims to investigate the dependence of heat transfer classification on the Reynolds number (Re) during flow around circular heated cylinders row. The investigated range of Re number varies from 4.5×103 up to 42×103. The distance between cylinders S was changed from 0.5d to 4d (where d is the cylinders dia). Cylinders surface temperature was kept constant. For each Re number, the case when the cylinders were mounted one after the other was investigated. To measure heat transfer and flow parameters (velocity, heat flux and heat transfer coefficient) near and at the cylinders surface, two experimental methods were used: gradient heatmetry and PIV. Heat flux and velocity fields were obtained from gradient heatmetry and PIV results, based on which the flow mode could be determined and compared with heat transfer mode. As a result, it was found that heat transfer is influenced by both the Reynolds number and the distance between the cylinders. The observed features are associated with influence on characteristics such as separation point location, boundary layer thickness, change in flow between the cylinders and vortices formation.

Numerical Simulation of Paraffin Melting Process in an Inclined Channel

Numerical simulation of the melting of paraffin in the inclined straight channel shows that the melting speed of paraffin is faster in the early stage and gradually slows down in the later stage. It is found that heat conduction is the main heat transfer mode in the early stage of paraffin melting. With the increasing number of liquid paraffin, natural convection occurs in the liquid paraffin. The liquid paraffin with higher temperature flows upward due to the effect of buoyance and lift, and convection heat transfer gradually increases and takes the dominant position in the melting process.

Highly Efficient Debromination of 4,4ʹ-dibrominated Diphenyl Ether by Organic-palygorskite Supported Pd/Fe Nanoparticles

Organic-palygorskite (OP) supported Pd/Fe nanoparticles composite (OP-Pd/Fe) was prepared by stepwise reduction method. The removal capacity of 4,4ʹ-dibrominated diphenyl ether (BDE15) by OP-Pd/Fe was compared with other various materials. For better understanding the possible mechanism, the synthesized and reacted OP-Pd/Fe materials were characterized by TEM, SEM, XRD, and XPS, respectively. The effects of major influencing parameters on the degradation of BDE15 were also studied. Benefit from the synergistic effect of the carrier and bimetallic nanoparticles, BDE15 could be completely debrominated into diphenyl ether (DE) under suitable conditions. A two-stage adsorption/debromination removal mechanism was proposed. The degradation of BDE15 with OP-Pd/Fe was mainly stepwise debromination reaction, and hydrogen transfer mode was assumed as the dominated debromination mechanism. The removal process fitted well to the pseudo first-order kinetic equation. The observed rate constants increased with increasing Pd loading and OP-Pd/Fe dosage, while decreased with increasing initial BDE15 concentration, the tetrahydrofuran/water ratio, and the initial pH of the solution. The work provides a new approach for the treatment of PBDEs pollution.

Effect of the Metal Transfer Mode on the Symmetry of Bead Geometry in WAAM Aluminum

The symmetrical nature in the case of wall fabrication by wire arc additive manufacturing (WAAM) has been observed in the literature, but it has not been studied as a source of knowledge. This paper focuses on the comparative study of three drop transfer methods employing Gas Metal Arc Welding (GMAW) technology, one of the most reported for the manufacture of aluminum alloys. The transfer modes studied are the well-known pulsed GMAW, cold arc, and the newer pulsed AC. The novelty of the last transfer mode is the reversal of the polarity during the preparation phase of the substance for droplet deposition. This study compares the symmetry of zero beads to determine the best parameters and transfer modes for wire arc additive manufacturing of 5 series aluminum. The pulsed transfer modes show values of 0.6 for symmetry ratio, which makes them more interesting strategies than cold arc with a symmetry ratio of 0.5. Furthermore, the methodology proposed in this study can be extrapolated to other materials manufactured with this technology.

Diagnosing of the presence of liquid inclusions in the gas pipelines

Due to the insufficiently effective gas drying in preparing it for further transport on the main pipeline in the composition of the gas remains a sufficient amount of fluid. The presence of liquid inclusions in the transported streams causes a nonequilibrium behavior of such systems, which is not taken into account in traditional calculation methods and increases the calculation error. Therefore, to select an adequate transfer mode, it is necessary to diagnose the internal structure of natural gas systems, which is the main task of studying this article. In working on the basis of a generalized model of motion of the relaxation medium in the pipeline by the introduction of the equation of the state for nonequilibrium gases, the calculated ratios are obtained to estimate the hydraulic and nonequilibrium parameters of the gas flow. In order to numerically implement these relations, a computational algorithm was drawn up and on the basis of the operational data of the actual gas pipeline obtained appropriate estimates. The results of the calculations were shown that both the density and the pressure relaxation times are rather significant. This indicates the presence of liquid inclusions in the transport stream. Thus, the authors proposed a numerically implemented procedure for diagnosing the presence of liquid inclusions in natural gases, which can be recommended for the use of services engaged in the operation of main gas pipelines. Keywords: natural gas; gas pipeline; liquid inclusions; model; diagnostics.