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Coupling effect between magnetic wires and its influence on high gradient magnetic separation performance

Jiang Yaxiong, Zeng Jianwu, Cao Mengbing, Yu Weijun, Xie Enlong, Chen Luzheng

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 1

art. no. 183620

EN

High gradient magnetic separation (HGMS) is effective for the separation of weakly magnetic minerals, and this method is achieved through the use of matrix, which is made of huge numbers of rod wires. So that the coupling effect of magnetic field and flow field between wires has a marked effect on the HGMS performance. In the investigation, the coupling effect between magnetic wires and its influence on high gradient magnetic separation performance were theoretically described and simulated using COMSOL Multiphysics. It is found that the magnetic field round a wire would be affected by the neighboring wires, and then a coupling effect of magnetic field between wires was produced, increasing the magnetic induction intensity on the upstream and downstream of wire surface. And the coupling effect of flow field could increase the slurry velocity at the regions of the wire surface with azimuth angles of 0° and 90°, which is beneficial for the selective capture of wire. These simulated results were basically validated with the experimental separation, using an innovative Magnetic Capture Analysis Method. It is found that the wire spacing has significant effect on the coupling effect of magnetic wires, and a critical spacing for wires could achieve an excellent coupling effect, which is beneficial for the improvement of HGMS performance. This investigation contributes to improve HGMS performance in concentrating fine weakly magnetic ores.

2

Dynamic coupling analysis between scale of network retail market and green circulation efficiency

Si Guoxing

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 1

127--137

EN

A sound circulation system is an important carrier for the development of the retail industry, and the promotion of green circulation efficiency (GCE) plays an important role in driving the market scale expansion of network retail (NR). This study uses the development status of China’s NR and circulation industries as basis to estimate the total carbon emissions (CE) of the circulation industry by using the system dynamics method. Moreover, this research measures China’s GCE by combining data envelopment analysis (DEA) and Malmquist index to construct a coupling analysis model to empirically investigate the dynamic coupling relationship between the NR scale and green circulation efficiency. Results indicate that China’s GCE is generally increasing, but growth rate fluctuates significantly. Additionally, the improvement of the quality and efficiency of China’s circulation industry has not yet formed a steady green path. China’s NR market scale continues to expand, but NR at this stage is still mainly concentrated in the eastern region. The efficiency of green circulation and scale of the NR market show a good coupling trend, but there is still a significant gap between the central and western regions. Accordingly, this study proposes that the construction of a green circulation system should be strengthened, and that the development of a green and efficient circulation industry should be taken as the engine of the NR scale expansion.

3

On the prediction of the effect of bi-ventricular assistance after cardiac explantation on the vascular flow physiology: A numerical study

Marcel Louis, Specklin Mathieu, Kouidri Smaine, Lescroart Mickael, Hébert Jean-Louis

Biocybernetics and Biomedical Engineering

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2024

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Vol. 44, no. 1

105--118

EN

Heart failure is a chronic and progressive condition characterized by the heart’s inability to pump sufficient blood to meet the body’s metabolic demands. It is a significant public health concern worldwide, associated with high morbidity, mortality, and healthcare costs. For advanced heart failure cases not responding to medical therapy, heart transplantation or mechanical circulatory support with ventricular assist devices (VADs) can be considered. In the specific case of bi-ventricular heart failure a replacement of both ventricles is required. In this context a Total Artificial Heart (TAH) may be proposed as a bridge to transplant solution. Additionally, bi-ventricular assist devices (BiVADs) are available to support both ventricles simultaneously. However Bi-ventricular heart failure management is difficult with poor outcomes. New surgical procedures appear to propose solutions after both ventricle failure. One of these intervention uses two continuous-flow VADs as a total artificial heart after cardiac explantation due to myocardial sarcoma. Unfortunately, this procedure makes patient management very difficult as pulmonary pressures and flow rate are no longer measurable after the surgical procedure. The setting of both pumps is hence a complex task for patient management. This article aims at helping clinicians on patient management undergoing double assistance after cardiac explantation by predicting the different outcomes on the vascular grid for all the possible rotational speed combination using a lumped model. Results provide a range of both pump operating conditions suitable for delivering a physiologically adapted flow to the vascular grid when combined with hypotensive treatments.

4

Special size effects in advanced single-gate and multiple-gate SOI transistors

Ohata A., Ritzenthaler R., Faynot O., Cristoloveanu S.

Journal of Telecommunications and Information Technology

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2007

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nr 2

14-24

EN

State-of-the-art SOI transistors require a very small body. This paper examines the effects of body thinning and thin-gate oxide in SOI MOSFETs on their electrical characteristics. In particular, the influence of film thickness on the interface coupling and carrier mobility is discussed. Due to coupling, the separation between the front and back channels is difficult in ultra-thin SOI MOSFETs. The implementation of the front-gate split C-V method and its limitations for determining the front- and back-channel mobility are described. The mobility in the front channel is smaller than that in the back channel due to additional Coulomb scattering. We also discuss the 3D coupling effects that occur in FinFETs with triple-gate and omega-gate configurations. In low-doped or tall fins the corner effect is suppressed. Narrow devices are virtually immune to substrate effects due to a strong lateral coupling between the two lateral sides of the gate. Short-channel effects are drastically reduced when the lateral coupling screens the drain influence.