Software‐defined networking approach for enhanced evolved packet core network

The evolved packet core (EPC) network is the mobile network standardized by the 3rd Generation Partnership Project and represents the recent evolution of mobile networks providing high‐speed data rates and on‐demand connectivity services. Software‐defined networking (SDN) is recently gaining momentum in network research as a new generation networking technique. An SDN‐based EPC is expected to introduce gains to the EPC control plane architecture in terms of simplified, and perhaps even software‐based, vendor independent infrastructure nodes. In this paper, we propose a novel SDN‐based EPC architecture along with the protocol‐level detailed implementation and provide a mechanism for identifying information fields exchanged between SDN‐EPC entities that maintains correct functionality with minimal impact on the conventional design. Furthermore, we present the first comprehensive network performance evaluation for the SDN‐based EPC versus the conventional EPC and provide a comparative analysis of 2 networks performances identifying potential bottlenecks and performance issues. The evaluation focuses on 2 network control operations, namely, the S1‐handover and registration operations, taking into account several factors, and assessing performance metrics such as end‐to‐end delay (E2ED) for completion of the respective control operation, and EPC nodes utilization figures.     

Analysis of steelmaking kinetics from IMPHOS pilot plant data

It is widely accepted that understanding the kinetics of steelmaking is a complex task, and reliable and validated kinetics models are required for developing successful steelmaking process models. Therefore, as an initial attempt, this paper analyses the applicability of first order kinetics to explain the steelmaking reaction kinetics using the published data in the IMproving Phosphorus Refining research report. The process data for 20 heats in a 6?tonne pilot plant were analysed for the removal of carbon, silicon, manganese and phosphorus using first order kinetics with static and dynamic equilibrium conditions. It was observed that the removal behaviour of silicon closely followed a first order kinetics relationship, while that of carbon only approximately followed a first order kinetics relationship. The removal of manganese did not show a good degree of fit with first order kinetics using static equilibrium condition, but a clear improvement was observed when calculated using dynamic equilibrium condition. In contrast, the kinetics of phosphorus oxidation did not follow any first order relationship.     

Influence of Ultrasonic Waves on the Processing of Cotton with Cationic Softener

In recent years, the textile industry has been forced to develop new technologies to reduce energy and water consumption. The use of ultrasound in textile wet processing is one solution to this problem. The aim of this work was to investigate the effects of ultrasonic energy on the processing of cotton with a cationic softener. For this purpose, cotton fabric was treated with a fatty acid amide derivative cationic softener in water using ultrasonic energy during treatment. The physical properties of the fabrics treated under different conditions are discussed. The results show that the treatment of fabrics with softeners in an ultrasound bath is more effective compared to conventional methods and that it enhances the physical properties of the cotton.     

Improvement of processing parameters by using processing aids during the linear low‐density polyethylene film blowing process

Polymer processing aids are used to improve processing properties in the polyethylene industry. These materials improve not only the physical and mechanical properties of the final products but also their processing properties. This paper studies some of the processing variables such as die pressure, melt temperature, masterbatch activity, and die gap by examining the functions of polymer processing aids and, last but not least, the effects on the film blowing process of two‐component processing aids containing a perfluorinated additive and polyoxyethylene. J. VINYL ADDIT. TECHNOL., 2010. © 2009 Society of Plastics Engineers     

A mathematical model for prediction of microporosity in aluminum alloy A356

In the present work, a mathematical model was developed based on finite difference method to predict the microporosity distribution in A356 aluminum alloy casting. Heat, mass, and gas conservation equations were solved in this model. Moreover, Darcy’s equation was considered in the mushy zone. Results show that the distribution and concentration of microporosities in cast parts vary with both cooling rate and initial gas content. Simulation results were compared with experimental data where proportionally good agreement with experimental results was found. Finally, a complex cast part was simulated presenting the ability of the model to predict the porosities in industrial cast parts.     

Development of a 2-D 2-group neutron noise simulator for hexagonal geometries

In this paper, the development of a neutron noise simulator for hexagonal-structured reactor cores using both the forward and the adjoint methods is reported. The spatial discretisation of both 2-D 2-group static and dynamic equations is based on a developed box-scheme finite difference method for hexagonal mesh boxes. Using the power iteration method for the static calculations, the 2-group neutron flux and its adjoint with the corresponding eigenvalues are obtained by the developed static simulator. The results are then benchmarked against the well-known CITATION computer code. The dynamic calculations are performed in the frequency domain which leads to discarding of the time discretisation. Then, the developed 2-D 2-group neutron noise simulator calculates both the discretised forward and the adjoint reactor transfer function between a point source and its induced neutron noise, by assuming the neutron noise source as an “absorber of variable strength” type. The neutron noise induced by a “vibrating absorber” type of noise source may also be modeled using the calculated transfer function. The viability of the simulator is verified for different benchmark cases.     

Experimental Measurement of Asymmetric Fluctuations of Poloidal Magnetic Field in Damavand Tokomak at Different Plasma Currents

Toroidal and Poloidal magnetic fields have an important effect on the tokomak topology. Damavand Tokomak is a small size tokomak characterized with k?=?1.2, B _t?=?1T, R ₀?=?36?cm, maximum plasma current is about 35?KA with a discharge time of 21?ms. In this experimental work, the variation of poloidal magnetic field on the torodial cross section is measured and analyzed. In order to measure the polodial magnetic field, 18 probes were installed on the edge of tokomak plasma with ?θ?=?18°, while a limiter was installed inside the torus. Plasma current, I _p, induces a polodial magnetic field, B _p, smaller than the torodial magnetic field B _t. Magnetic lines B produced as a combination of B _t and B _p, are localized on the nested toroidal magnetic surfaces. The presence of polodial magnetic field is necessary for particles confinement. Mirnov oscillations are the fluctuations of polodial magnetic field, detected by magnetic probes. Disrupted instability in Tokomak typically starts with mirnov oscillations which appear as fluctuations of polodial magnetic field and is detected by magnetic probes. Minor disruptions inside the plasma can contain principal magnetic islands and their satellites can cause the annihilation of plasma confinement. Production of thin layer of turbulent magnetic field lines cause minor disruption. Magnetic limiter may cause the deformation of symmetric equilibrium configuration and chaotic magnetic islands reveal in plasma occurring in thin region of chaotic field lines close to their separatrix. The width of this chaotic layer in the right side of poloidal profile of Damavand Tokomak is smaller than the width in the left side profile because of Shafranov displacement. Ergodic region in the left side of profile develops a perturbation on the magnetic polodial field lines, B _p, that are greater in magnitude than that in the right side, although the values of B _p on the left side are smaller than that on the right side of the profile. The Left side of profile is close to the principal magnetic axis and the right side is away from Z axis of Tokamak.     

The oxide electrochemistry of ruthenium and its relevance to trench liner applications in damascene copper plating

There is considerable interest in the use of ruthenium as an ultrathin trench liner in damascene copper plating used to fabricate on-chip interconnects. The problem is that when freshly deposited ruthenium films are exposed to air, their surfaces tend to undergo spontaneous oxidation, and such deposits (as demonstrated here) are reluctant to undergo reduction. Copper deposition in an acid plating bath occurs readily on the oxidized ruthenium, but the presence of oxide is known to have a detrimental effect both on the copper superfilling process and copper adhesion at the Ru/Cu interface.     

A 5th-order ΣΔ modulator with combination of op-Amp and CBSC circuit for ADSL applications

In this letter, a 5th-Order single-loop low distortion Sigma–Delta Modulator (SDM) is implemented with the combination of the comparator-based switched-capacitor (CBSC)-based and op-amp-based techniques for asymmetric digital subscriber line (ADSL) applications. This structure, which uses integrator (CBSC-based) and IIR filter (op-amp-based) concurrently, has relatively fewer feed-forward paths and modulator coefficients for sensitivity reduction to mismatch. To lower the power consumption of the modulator, the integrators are implemented with CBSC, the IIR filter block is implemented by single OTA, and a passive adder is used to realize the adder at the input of the 5-bit quantizer. The design purpose is minimizing the power consumption while the dynamic performance maintains high. As shown in the simulation result, for a 2-MHz signal bandwidth, the modulator achieves a dynamic range (DR) of 86.5 dB and a peak signal-to-noise and distortion ratio (SNDR) of 85 dB with an oversampling ratio of 8. In addition it consumes 18.75 mW from a 1.8-V power supply at 32 MS/s, which obtains a figure of merit of 1.6e−3.