scholarly journals Evidence of Bermuda Hot and Wet Upwelling From Novel Three‐Dimensional Global Mantle Electrical Conductivity Image

2020 ◽  
Vol 21 (6) ◽  
Author(s):  
Shiwen Li ◽  
Aihua Weng ◽  
Yanhui Zhang ◽  
Adam Schultz ◽  
Yabin Li ◽  
...  
RSC Advances ◽  
2016 ◽  
Vol 6 (27) ◽  
pp. 22364-22369 ◽  
Author(s):  
Zhiduo Liu ◽  
Dianyu Shen ◽  
Jinhong Yu ◽  
Wen Dai ◽  
Chaoyang Li ◽  
...  

Three dimensional graphene foam incorporated into epoxy matrix greatly enhance its thermal conductivity (up to 1.52 W mK−1) at low graphene foam loading (5.0 wt%), over an eight-fold enhancement in comparison with that of neat epoxy.


2020 ◽  
Vol 8 (34) ◽  
pp. 11748-11759 ◽  
Author(s):  
Jingnan Ni ◽  
Ruoyu Zhan ◽  
Jun Qiu ◽  
Jincheng Fan ◽  
Binbin Dong ◽  
...  

Three-dimensional graphene aerogel/polydimethylsiloxane metacomposites with an integral multi-interface structure possess adjustable negative permittivity, excellent microwave absorption and electromagnetic interference shielding.


2020 ◽  
Vol 26 (4) ◽  
pp. 765-776 ◽  
Author(s):  
Gurminder Singh ◽  
Pulak Mohan Pandey

Purpose The purpose of this study is to study the mechanical, tribological and electrical properties of the copper-graphene (Cu-Gn) composites fabricated by a novel rapid tooling technique consist of three-dimensional printing and ultrasonic-assisted pressureless sintering (UAPS). Design/methodology/approach Four different Cu-Gn compositions with 0.25, 0.5, 1 and 1.5 per cent of graphene were fabricated using an amalgamation of three-dimensional printing and UAPS. The polymer 3d printed parts were used to prepare mould cavity and later the UAPS process was used to sinter Cu-Gn powder to acquire free-form shape. The density, hardness, wear rate, coefficient of friction and electrical conductivity were evaluated for the different compositions of graphene and compared with the pure copper. Besides, the comparison was performed with the conventional method. Findings Cu-Gn composites revealed excellent wear properties due to higher hardness, and the lubrication provided by the graphene. The electrical conductivity of the fabricated Cu-Gn composites started increasing initially but decreased afterwards with increasing the content of graphene. The UAPS fabricated composites outperformed the conventional method manufactured samples with better properties such as density, hardness, wear rate, coefficient of friction and electrical conductivity due to homogeneous mixing of metal particles and graphene. Originality/value The fabrication of Cu-Gn composite freeform shapes was found to be difficult using conventional methods. The novel technique using a combination of polymer three-dimensional printing and UAPS as rapid tooling was introduced for the fabrication of freeform shapes of Cu-Gn composites and mechanical, tribological and electrical properties were studied. The method can be used to fabricate optimized complex Cu-Gn structures with improved wear and electrical applications.


2020 ◽  
Vol 11 (5) ◽  
pp. 1342-1346 ◽  
Author(s):  
Hanna C. Wentz ◽  
Grigorii Skorupskii ◽  
Ana B. Bonfim ◽  
Jenna L. Mancuso ◽  
Christopher H. Hendon ◽  
...  

Redox-active ligands are used to reversibly tune electrical conductivity in a porous 3D metal–organic framework (MOF).


Author(s):  
Esmaiil Ghasemisahebi ◽  
Hassan Bararnia ◽  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin

In this study deformation and breakup of a falling drop which is surrounded by another liquid are modeled numerically. The drop is influenced by an external electric field which is applied uniformly on the side walls of the domain. An open-source volume-of-fluid solver, Gerris with dynamic adaptive grid refinement has been used for numerically modeling the three-dimensional deformation of a falling droplet. The numerical results are presented for various values of density ratios and electrical conductivity and permittivity. The current numerical results are compared with previous experimental and analytical works which shows a great agreement between them.


2019 ◽  
Vol 21 (8) ◽  
pp. 4145-4154 ◽  
Author(s):  
Chun Tan ◽  
Matthew D. R. Kok ◽  
Sohrab R. Daemi ◽  
Daniel J. L. Brett ◽  
Paul R. Shearing

A sulfur electrode was imaged with X-ray micro and nano computed tomography for the modelling of effective molecular diffusivity and electrical conductivity through flux based simulations.


2020 ◽  
Author(s):  
Alexey Kuvshinov ◽  
Alexander Grayver ◽  
Lars Tøffner-Clausen ◽  
Nils Olsen

<p>In this contribution, we report on our recent attempts to detect lateral variations of the electrical conductivity at mid mantle depths (400­ – 1600 km) using 6 years of Swarm, Cryosat-2 and observatory magnetic data. The approach involves a three-dimensional (3-D) inversion of matrix Q-responses. These responses relate spherical harmonic coefficients of external (inducing) and internal (induced) parts of the magnetic potential, derived for geomagnetic variations at periods longer than 1 day and hence mainly describing signals of magnetospheric origin (i.e. external also to satellites, as required). In addition to the inversion results, we discuss potential ways to improve the recovery of 3-D conductivity structures in the mantle.</p>


2011 ◽  
Vol 1304 ◽  
Author(s):  
S. Xu ◽  
O. Rezvanian ◽  
K. Peters ◽  
M.A. Zikry

ABSTRACTA three-dimensional (3D) carbon nanotube (CNT) network computational model was developed to investigate the electrical conductivity and current flow in polymer composites with randomly dispersed CNTs. A search algorithm was developed to determine conductive paths for 3D CNT arrangements and to account for electron tunneling effects. Tunneled currents were obtained as a function of tunneling distance and matrix material. Several possible CNT conductive paths were obtained and finite-element representative volume elements (RVEs) were then used to predict current densities in different CNT arrangements. The predictions indicate that random CNT arrangements can be optimized for current transport.


2012 ◽  
Vol 622-623 ◽  
pp. 781-786
Author(s):  
Sarojini Swain ◽  
Subhendu Bhattacharya ◽  
Ram Avatar Sharma ◽  
Lokesh Chaudhari

Hydroxyl modified multi-walled carbon nanotubes (OH-MWCNT)/ polyurethane (PU) and graphene nanosheets (GNS)/PU composites were prepared by dispersing the OH-MWCNT and GNS at different wt % in to the PU matrix. It was found that the electrical percolation threshold of the GNS/PU composite is much higher compared to that of OH-MWCNT/PU and also the electrical conductivity of the OH-MWCNT/PU composite is higher than the GNS/PU composite in the same level of filler content. This may be due to the two composites having different electrical conduction mechanisms: The OH-MWCNT/PU composite represents a three dimensional conduction system while, the GNS/PU composite represents a two dimensional conduction system. The improvement in the electrical conductivity with the incorporation of GNS as a filler in the composite is far lower than what theoretically expected. It is also observed that the tensile strength of the OH-MWCNT/PU composite is higher compared to the GNS/PU in the same level filler content.


Sign in / Sign up

Export Citation Format

Share Document