scholarly journals Numerical Study of the Influence of Water Evaporation on Radiofrequency Ablation

2013 ◽  
Author(s):  
Qing Zhu ◽  
Binbin Ying ◽  
Aili Zhang ◽  
Lisa X. Xu
Keyword(s):  
Numerical Study ◽  
Tumor Therapy ◽  
Electrical Current ◽  
Frictional Heat ◽  
Water Evaporation ◽  
Minimal Invasiveness ◽  
Electrode Wall ◽  
Influence Of Water ◽  
Distant Part ◽  
Intracellular Ions

Radiofrequency (RF) ablation is one of the promising technologies of tumor therapy due to its minimal invasiveness and other advantages. The high frequency alternating electrical current makes movement of the intracellular ions, results in frictional heat inside the tumor tissue and local temperature rising. Temperature of the tissue near the RF electrode increases much faster than the distant part. When it reaches the vapor (boiling) point, excessive evaporation takes place and increases electrical impedance between the electrode and the targeted tissue. This has been a major obstacle for its application. Coolants such as water circulating in the electrodes has been proposed, but as the coolants are only effective on the electrode wall, quick evaporation and correspondent carbonization still exists.

scholarly journals Numerical study of the influence of water evaporation on radiofrequency ablation

2013 ◽  
Vol 12 (1) ◽  
pp. 127 ◽  
Author(s):  
Qing Zhu ◽  
Yuanyuan Shen ◽  
Aili Zhang ◽  
Lisa X Xu
Keyword(s):  
Radiofrequency Ablation ◽  
Numerical Study ◽  
Water Evaporation ◽  
Influence Of Water

scholarly journals A numerical study on the effect of salinity on stability of an unsaturated railway embankment under rainfall

2020 ◽  
Vol 195 ◽  
pp. 01004
Author(s):  
Ali Kolahdooz ◽  
Hamed Sadeghi ◽  
Mohammad Mehdi Ahmadi
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Water ◽  
Water Retention ◽  
Numerical Study ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Unsaturated Hydraulic Conductivity ◽  
Influence Of Water ◽  
Dispersive Soils

Dispersive soils, as one of the main categories of problematic soils, can be found in some parts of the earth, such as the eastern-south of Iran, nearby the Gulf of Oman. One of the most important factors enhancing the dispersive potential is the existence of dissolved salts in the soil water. The main objective of this study is to explore the influence of water salinity on the instability of a railway embankment due to rainfall infiltration. In order to achieve this goal, the embankment resting on a dispersive stratum is numerically modeled and subjected to transient infiltration flow. The effect of dispersion is simplified through variations in the soil-water retention curve with salinity. The measured water retention curves revealed that by omitting the natural salinity in the soil-water, the retention capability of the soil decreases; therefore, the unsaturated hydraulic conductivity of the soil stratum will significantly decline. According to the extensive decrease in the hydraulic conductivity of the desalinated materials, the rainfall cannot infiltrate in the embankment and the rainfall mostly runs off. However, in the saline embankment, the infiltration decreases the soil suction; and consequently, the factor of safety of the railway embankment decreases.

scholarly journals Influence of water evaporation/absorption on the stability of glycerol–water marbles

RSC Advances ◽  
2019 ◽  
Vol 9 (59) ◽  
pp. 34465-34471 ◽  
Author(s):  
Xinxing Lin ◽  
Wei Ma ◽  
Lihui Chen ◽  
Liulian Huang ◽  
Hui Wu ◽  
...  
Keyword(s):  
Water Evaporation ◽  
Glycerol Water ◽  
Influence Of Water ◽  
The Stability

The influence of water evaporation and absorption on the stability of aqueous glycerol marbles was investigated.

scholarly journals Self-remedied Nanomedicine for Surmounting the Achilles's Heel of Photodynamic Tumor Therapy

2021 ◽  
Author(s):  
Xiang Zhou ◽  
Jia-Qi Huang ◽  
Ling-Shan Liu ◽  
Fu-An Deng ◽  
Yi-Bin Liu ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Tumor Suppression ◽  
Hydrophobic Interactions ◽  
Drug Loading ◽  
Tumor Therapy ◽  
Hypoxia Inducible Factor ◽  
Tumor Hypoxia ◽  
Uniform Size ◽  
Minimal Invasiveness ◽  
Carrier Free

Abstract Background: Photodynamic therapy (PDT) has been recognized as a promising tumor treatment for its minimal invasiveness, low side effects and on-demand light controllability. However, the oxygen-dependent PDT could exacerbate tumor hypoxia to upregulate the expression of hypoxia-inducible factor-1α (HIF-1α), which would promote tumor growth and metastasis. Inhibition of HIF-1α activity is very necessary to PDT for effective tumor suppression.Results: Herein, we developed a self-remedied nanomedicine based on a photosensitizer and a HIF-1α inhibitor to surmount the Achilles' heel of PDT for enhanced antitumor efficacy. Specifically, the nanomedicine (designated as CYC-1) was prepared by the self-assembly of Ce6 and YC-1 through π-π stacking and hydrophobic interactions. Carrier-free CYC-1 held an extremely high drug loading rate, uniform size distribution and favorable stability. Compared with free Ce6, CYC-1 exhibited an improved cellular uptake behavior and an enhanced ROS production capability. Besides, CYC-1 had the overwhelming superiority on restraining tumor proliferation over the combined administration of Ce6 and YC-1. More importantly, CYC-1 preferred to accumulate in tumor tissue for efficient PDT by inhibiting the activity of HIF-1α. Ultimately, this YC-1-assistant PDT effectively restrained the tumor growth and caused a low system toxicity. Conclusions: This carrier-free self-remedied strategy overcame the Achilles' heel of PDT on tumor suppression while induced a minimal side effect, which would expedite the development and clinical translation of nanomedicine for PDT against hypoxic tumors.

scholarly journals Numerical Simulation of Fog Transport in a Horizontal Channel

2020 ◽  
Vol 330 ◽  
pp. 01033
Author(s):  
Nihel Grich ◽  
Walid Foudhil ◽  
Souad Harmand ◽  
Sadok Ben Jabrallah
Keyword(s):  
Volume Fraction ◽  
Numerical Study ◽  
Horizontal Channel ◽  
Comsol Multiphysics ◽  
Water Volume ◽  
Influence Of Water ◽  
Simulation Results ◽  
Water Volume Fraction ◽  
Phase Water ◽  
2D Numerical Model

Water spraying in exchanger systems is widely used to allow cooling and improving their performance. However, transfers within the spray mixture are difficult to express because the combined mass and heat are transferred between phases, which complicates the design of the spray systems. This article presents a numerical study of the influence of water volume fraction on the distribution of the temperature in a canal. A 2D numerical model of a horizontal channel was generated and the equations governing the continuous phases (air) and the dispersed phase (water) were developed. These equations were solved using Comsol multiphysics. A comparison of the simulation results and those of the experiment reveals an acceptable concordance.

Numerical Study of Long Channel Carbon Nanotube Based Transistors by Considering Variation in CNT Diameter

2020 ◽  
Vol 61 ◽  
pp. 78-87
Author(s):  
Sajjad Dehghani
Keyword(s):  
Carbon Nanotube ◽  
Chemical Sensors ◽  
Field Effect Transistors ◽  
Numerical Study ◽  
Electrical Current ◽  
Light Emitters ◽  
Short Channel ◽  
Numerical Studies ◽  
Long Channel ◽  
Good Agreement

While much numerical studies have been done on short channel carbon nanotube field effect transistors (CNT-FETs), there are only a few numerical reports on long channel devices. Long channel CNT-FETs have been widely used in chemical sensors and biosensors as well as light emitters. Therefore, numerical study is helpful for a better understanding of the behavior of such devices. In this paper, we numerically analyze long-channel CNT-FETs by solving the continuity and charge equations self-consistently. To increase the accuracy of simulation, filed-dependent mobility is applied to the equations. Furthermore, a method is proposed to obtain the electrical current of transistors as a function of CNT diameter. Obtained results are in good agreement with the previous experimental data. It is found that compared to a CNT-based resistor, the dependence of current on diameter is much higher in a CNT-FET. Finally, reproducibility of transistors based on the arrays of random CNTs of 1-2 nm diameter in terms of the CNTs number is also investigated.

An Impact of a Low Voltage Steady Electrical Current on the Solidification of a Binary Metal Alloy: A Numerical Study

2007 ◽  
Vol 78 (5) ◽  
pp. 402-408 ◽  
Author(s):  
Petr A. Nikrityuk ◽  
Kerstin Eckert ◽  
Roger Grundmann ◽  
Yuansheng S. Yang
Keyword(s):  
Low Voltage ◽  
Numerical Study ◽  
Electrical Current ◽  
Metal Alloy ◽  
Binary Metal

scholarly journals Experimental researches in electricity.—Fifth series

1837 ◽  
Vol 3 ◽  
pp. 211-211
Keyword(s):  
Electrical Current ◽  
The Other ◽  
Simultaneous Action ◽  
Electrical Machine ◽  
Chemical Decomposition ◽  
Effect Decomposition ◽  
Influence Of Water ◽  
The Common ◽  
Experimental Researches ◽  
Satisfactory Manner

The object of the author in this paper is to investigate the nature of electro-chemical decomposition. From the consideration of the circumstances of difference that mark the electricities obtained from the common electrical machine, and from the voltaic battery, and of which he had already established the theory in preceding papers, he was led to expect that the employment of the former in effecting chemical decomposition would exhibit some new conditions of that action, evolve new series of the internal arrangements and changes of the substance under decomposition, and perhaps give efficient powers over matter as yet undecomposed. For the purpose of greater distinctness, he divides the inquiry into three heads. In the first, he treats of some new conditions of electro-chemical decomposition, and shows that that effect does not depend upon the simultaneous action of two metallic plates, since a single pole might be used to effect decomposition; in which case one or other of the elements liberated passes to that pole, and the other element to the other extremity of the apparatus, the air itself acting as a pole. In the second, he considers the influence of water in electro-chemical decomposition; and he combats the opinion that the presence of that fluid is essential to the process is erroneous, and shows that water is merely one of a very numerous class of bodies, by means of which the electric influence is conducted and decomposition effected. In the third, he enters at large into the investigation of the theory of electro-chemical decomposition, and after discussing at some length the various theories of different writers on this curious subject, he is led to consider the effect in question as produced by an internal corpuscular action, exerted according to the direction of the electrical current, and as being the result of a force either superadded or giving direction to the ordinary chemical affinity of the bodies present; that is, modifying the affinities in the particles through which the current is passing, so that they act with greater force in one direction than in another, and consequently cause them to travel, by a series of successive decompositions and recompositions, in opposite directions, so as to be finally disengaged at the boundaries of the decomposing body. Various experiments are detailed in corroboration of these views, which appear to explain, in a satisfactory manner, all the prominent features of electro-chemical decomposition. decomposition.

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