Large-Scale Assembly of Carbon Nanotubes

2004 ◽  
Author(s):  
T. El-Aguizy ◽  
Sang-Gook Kim
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Large Scale ◽  
Small Scale ◽  
Manufacturing Processes ◽  
Micro Scale ◽  
Multi Scale ◽  
Novel Method ◽  
Functionalization Of Carbon Nanotubes

The scale decomposition of a multi-scale system into small-scale order domains will reduce the complexity of the system and will subsequently ensure a success in nanomanufacturing. A novel method of assembling individual carbon nanotube has been developed based on the concept of scale decomposition. Current technologies for organized growth of carbon nanotubes are limited to very small-scale order. The nanopelleting concept is to overcome this limitation by embedding carbon nanotubes into micro-scale pellets that enable large-scale assembly as required. Manufacturing processes have been developed to produce nanopellets, which are then transplanted to locations where the functionalization of carbon nanotubes are required.

scholarly journals The Effect of Multi-Scale Faults and Fractures on Oil Enrichment and Production in Tight Sandstone Reservoirs: A Case Study in the Southwestern Ordos Basin, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Lianbo Zeng ◽  
Wenya Lyu ◽  
Yunzhao Zhang ◽  
Guoping Liu ◽  
Shaoqun Dong
Keyword(s):  
Large Scale ◽  
Ordos Basin ◽  
Oil Production ◽  
Small Scale ◽  
Type I ◽  
Type Ii ◽  
Tight Sandstone ◽  
Micro Scale ◽  
Multi Scale

The Chang 8 Member of the Upper Triassic Yanchang Formation in the southwestern Ordos Basin is a typical tight sandstone reservoir and has an average porosity of 8.60% and air permeability 0.20 mD. Multi-scale faults and fractures are widely developed in these reservoirs. In this study, three-dimensional seismic data, outcrops, cores, imaging logs, and thin sections were used to classify faults and fractures at multiple scales. Combined with the oil production data, the influence of multi-scale faults and fractures on the oil enrichment and production was analyzed. The results show multi-scale faults and fractures can be divided into six levels: type-I faults, type-II faults, large-scale fractures, mesoscale fractures, small-scale fractures, and micro-scale fractures. As the scale decreases, the number of fractures increases in a power function. Type-I faults cut the caprocks and are not conducive to the preservation of oil. Type-II faults connect the source rocks and reservoirs and are migration channels of the oil source. Large-scale fractures cut the mudstone interlayer and are the seepage channel inside the reservoir. Mesoscale fractures are controlled by thick interlayers, and small-scale fractures are restricted by thin interlayers or layer interfaces. These fractures are the main seepage channels and effective storage spaces. Micro-scale fractures serve as important storage spaces for these reservoirs. The case study of oil reservoir development proves that type-I faults have the greatest impact on fluid flow, while wells drilled into the type-II faults zone have a higher oil production capacity. The oil production changes with the development degree of fractures in different scales, strikes, and positions of faults. Meso- and small-scale fractures are the key to influencing the early single-well production, and micro-scale fractures are conducive to the stable production of single wells. Consequently, multi-scale faults and fractures have significantly different effects on the oil enrichment and production of tight sandstone reservoirs, and the research conclusions can guide to the exploration and development of such similar reservoirs.

scholarly journals Multi-Scale Ionospheric Anomalies Monitoring and Spatio-Temporal Analysis during Intense Storm

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 215
Author(s):  
Na Cheng ◽  
Shuli Song ◽  
Wei Li
Keyword(s):  
Magnetic Storm ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Ionospheric Disturbance ◽  
Ionospheric Scintillation ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Multi Scale ◽  
Intense Storm

The ionosphere is a significant component of the geospace environment. Storm-induced ionospheric anomalies severely affect the performance of Global Navigation Satellite System (GNSS) Positioning, Navigation, and Timing (PNT) and human space activities, e.g., the Earth observation, deep space exploration, and space weather monitoring and prediction. In this study, we present and discuss the multi-scale ionospheric anomalies monitoring over China using the GNSS observations from the Crustal Movement Observation Network of China (CMONOC) during the 2015 St. Patrick’s Day storm. Total Electron Content (TEC), Ionospheric Electron Density (IED), and the ionospheric disturbance index are used to monitor the storm-induced ionospheric anomalies. This study finally reveals the occurrence of the large-scale ionospheric storms and small-scale ionospheric scintillation during the storm. The results show that this magnetic storm was accompanied by a positive phase and a negative phase ionospheric storm. At the beginning of the main phase of the magnetic storm, both TEC and IED were significantly enhanced. There was long-duration depletion in the topside ionospheric TEC during the recovery phase of the storm. This study also reveals the response and variations in regional ionosphere scintillation. The Rate of the TEC Index (ROTI) was exploited to investigate the ionospheric scintillation and compared with the temporal dynamics of vertical TEC. The analysis of the ROTI proved these storm-induced TEC depletions, which suppressed the occurrence of the ionospheric scintillation. To improve the spatial resolution for ionospheric anomalies monitoring, the regional Three-Dimensional (3D) ionospheric model is reconstructed by the Computerized Ionospheric Tomography (CIT) technique. The spatial-temporal dynamics of ionospheric anomalies during the severe geomagnetic storm was reflected in detail. The IED varied with latitude and altitude dramatically; the maximum IED decreased, and the area where IEDs were maximum moved southward.

scholarly journals Study on the nonlinear vibration of embedded carbon nanotube via the Hamiltonian-based method

2021 ◽  
pp. 146134842110327
Author(s):  
Kang-Jia Wang ◽  
Guo-Dong Wang
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nonlinear Vibration ◽  
Elastic Medium ◽  
Numerical Results ◽  
Frequency Property ◽  
New Novel ◽  
Novel Method

This article mainly studies the vibration of the carbon nanotubes embedded in elastic medium. A new novel method called the Hamiltonian-based method is applied to determine the frequency property of the nonlinear vibration. Finally, the effectiveness and reliability of the proposed method is verified through the numerical results. The obtained results in this work are expected to be helpful for the study of the nonlinear vibration.

Novel Method of Converting Metallic-Type Carbon Nanotubes to Semiconducting-Type Carbon Nanotube Field-Effect Transistors

2006 ◽  
Vol 45 (4B) ◽  
pp. 3680-3685 ◽  
Author(s):  
Bae-Horng Chen ◽  
Jeng-Hua Wei ◽  
Po-Yuan Lo ◽  
Zing-Way Pei ◽  
Tien-Sheng Chao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Novel Method

Future trends in carbon nanotubes: Process towards a viable biomedical solution

2021 ◽  
Vol 06 ◽  
Author(s):  
Raja Murugesan ◽  
Sureshkumar Raman ◽  
Arun Radhakrishnan
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Biomedical Applications ◽  
Scale Up ◽  
Diagnostic Techniques ◽  
Nano Composite ◽  
Methods Of Synthesis ◽  
In Trans ◽  
Functionalization Of Carbon Nanotubes

Background: Recently, Nanomaterials based nano-composite materials play the role of various field. Especially, Carbon nanotube based materials are involved in the bio-medical applications.Since, their exclusive and exciting property, researchers worldwide have extensively involved in trans-modulating the carbon nanotubes into a viable medico-friendly system. Objective: These active researches paved the path towards targeted drug delivery, diagnostic techniques, and bio-analytical applications. Despite these exciting properties, which accomplish the probable for biomedical applications, they hold Biosafety issues. Methods: This broad-spectrum review has discussed different aspects of carbon nanotubes and carbon nanotube-based systems related to biomedical applications. Results: Adding to this, a short chronological description of these tiny yet powerful particles given, followed by a discussion regarding their types, properties, methods of synthesis, scale-up, purification techniques and characterization aspects of carbon nanotubes. Conclusion: In the later part, the functionalization of carbon nanotubes was reviewed in detail, which is important to make them biocompatible and stable in biological systems and render them a great property of loading various biomolecules diagnostic and therapeutic moieties. Lastly, an inclusive description of the potential biomedical applications has been given followed by insights into the future.

scholarly journals Carbon Nanotube Sheet-Synthesis and Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2023
Author(s):  
Megha Chitranshi ◽  
Anuptha Pujari ◽  
Vianessa Ng ◽  
Daniel Chen ◽  
Devika Chauhan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Large Scale ◽  
Hydrogen Gas ◽  
Synthesis Process ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Metal Ceramic ◽  
Commercial Applications ◽  
Manufacturing Problems

Decades of extensive research have matured the development of carbon nanotubes (CNTs). Still, the properties of macroscale assemblages, such as sheets of carbon nanotubes, are not good enough to satisfy many applications. This paper gives an overview of different approaches to synthesize CNTs and then focuses on the floating catalyst method to form CNT sheets. A method is also described in this paper to modify the properties of macroscale carbon nanotube sheets produced by the floating catalyst method. The CNT sheet is modified to form a carbon nanotube hybrid (CNTH) sheet by incorporating metal, ceramic, or other types of nanoparticles into the high-temperature synthesis process to improve and customize the properties of the traditional nanotube sheet. This paper also discusses manufacturing obstacles and the possible commercial applications of the CNT sheet and CNTH sheet. Manufacturing problems include the difficulty of injecting dry nanoparticles uniformly, increasing the output of the process to reduce cost, and safely handling the hydrogen gas generated in the process. Applications for CNT sheet include air and water filtering, energy storage applications, and compositing CNTH sheets to produce apparel with anti-microbial properties to protect the population from infectious diseases. The paper also provides an outlook towards large scale commercialization of CNT material.

Critical Buckling Load of Triple-Walled Carbon Nanotube Based on Nonlocal Elasticity Theory

2020 ◽  
Vol 62 ◽  
pp. 108-119
Author(s):  
Tayeb Bensattalah ◽  
Ahmed Hamidi ◽  
Khaled Bouakkaz ◽  
Mohamed Zidour ◽  
Tahar Hassaine Daouadji
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Axial Compression ◽  
Buckling Load ◽  
Small Scale ◽  
Beam Model ◽  
Buckling Loads ◽  
Critical Buckling Load ◽  
Nonlocal Continuum Theory ◽  
Walled Carbon Nanotubes

The present paper investigates the nonlocal buckling of Zigzag Triple-walled carbon nanotubes (TWCNTs) under axial compression with both chirality and small scale effects. Based on the nonlocal continuum theory and the Timoshenko beam model, the governing equations are derived and the critical buckling loads under axial compression are obtained. The TWCNTs are considered as three nanotube shells coupled through the van der Waals interaction between them. The results show that the critical buckling load can be overestimated by the local beam model if the small-scale effect is overlooked for long nanotubes. In addition, a significant dependence of the critical buckling loads on the chirality of zigzag carbon nanotube is confirmed, and these are then compared with: A single-walled carbon nanotubes (SWCNTs); and Double-walled carbon nanotubes (DWCNTs). These findings are important in mechanical design considerations and reinforcement of devices that use carbon nanotubes.

scholarly journals Multi-Scale Remote Sensing Semantic Analysis Based on a Global Perspective

2019 ◽  
Vol 8 (9) ◽  
pp. 417 ◽  
Author(s):  
Wei Cui ◽  
Dongyou Zhang ◽  
Xin He ◽  
Meng Yao ◽  
Ziwei Wang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Receptive Field ◽  
Large Scale ◽  
Semantic Information ◽  
Short Term Memory ◽  
Global Perspective ◽  
Small Scale ◽  
Multi Scale ◽  
Memory Network ◽  
Long Short Term Memory

Remote sensing image captioning involves remote sensing objects and their spatial relationships. However, it is still difficult to determine the spatial extent of a remote sensing object and the size of a sample patch. If the patch size is too large, it will include too many remote sensing objects and their complex spatial relationships. This will increase the computational burden of the image captioning network and reduce its precision. If the patch size is too small, it often fails to provide enough environmental and contextual information, which makes the remote sensing object difficult to describe. To address this problem, we propose a multi-scale semantic long short-term memory network (MS-LSTM). The remote sensing images are paired into image patches with different spatial scales. First, the large-scale patches have larger sizes. We use a Visual Geometry Group (VGG) network to extract the features from the large-scale patches and input them into the improved MS-LSTM network as the semantic information, which provides a larger receptive field and more contextual semantic information for small-scale image caption so as to play the role of global perspective, thereby enabling the accurate identification of small-scale samples with the same features. Second, a small-scale patch is used to highlight remote sensing objects and simplify their spatial relations. In addition, the multi-receptive field provides perspectives from local to global. The experimental results demonstrated that compared with the original long short-term memory network (LSTM), the MS-LSTM’s Bilingual Evaluation Understudy (BLEU) has been increased by 5.6% to 0.859, thereby reflecting that the MS-LSTM has a more comprehensive receptive field, which provides more abundant semantic information and enhances the remote sensing image captions.

Research on the Creation of Small-Scale English-Chinese Parallel Corpus for Manufacturing Systems

2013 ◽  
Vol 421 ◽  
pp. 725-730
Author(s):  
Song Bin Bao
Keyword(s):  
Teaching And Learning ◽  
Manufacturing Systems ◽  
Large Scale ◽  
Small Scale ◽  
Chinese Word Segmentation ◽  
Translation Memory ◽  
Parallel Corpus ◽  
Novel Method ◽  
Chinese Texts ◽  
Education In China

English, which is specially used in the field of manufacturing systems, belongs to ESP (English for specific purposes). In order to improve the effect of ESP education in China, it is very necessary to create an English-Chinese parallel corpus for aiding ESP teaching and learning. In this paper, a novel method is presented to create a small-scale English-Chinese parallel corpus by means of TMS (translation memory system). Firstly, the suitable English and Chinese texts are collected from network, publication and human translation; secondly, The English and Chinese texts are aligned and formatted by using the related TMS functions; then Chinese texts are split into words by using ICWSS (Intelligent Chinese Word Segmentation System); finally, the English-Chinese corpus is stored in cloud database. This small-scale English-Chinese parallel corpus can be searched through ParaConc and meet the basic needs of ESP teaching and learning. Since the method does not need to design new algorithm nor develop new software system, the construction of the corpus is much easier and more flexible compared to general large-scale corpus.

Wavelet Analysis on Eddy Structure in Micro Bubble Two Phase Flow Using PIV

2004 ◽  
Author(s):  
Ling Zhen ◽  
Claudia del Carmen Gutierrez-Torres
Keyword(s):  
Boundary Layer ◽  
Turbulent Flow ◽  
Drag Reduction ◽  
Large Scale ◽  
Operating Conditions ◽  
Small Scale ◽  
Turbulent Structures ◽  
Two Phase ◽  
Multi Scale ◽  
Eddy Structures

The question of “where and how the turbulent drag arises” is one of the most fundamental problems unsolved in fluid mechanics. However, the physical mechanism responsible for the friction drag reduction is still not well understood. Over decades, it is found that the turbulence production and self-containment in a boundary layer are organized phenomena and not random processes as the turbulence looks like. The further study in the boundary layer should be able to help us know more about the mechanisms of drag reduction. The wavelet-based vector multi-resolution technique was proposed and applied to the two dimensional PIV velocities for identifying the multi-scale turbulent structures. The intermediate and small scale vortices embedded within the large-scale vortices were separated and visualized. By analyzing the fluctuating velocities at different scales, coherent eddy structures were obtained and this help us obtain the important information on the multi-scale flow structures in the turbulent flow. By comparing the eddy structures in different operating conditions, the mechanism to explain the drag reduction caused by micro bubbles in turbulent flow was proposed.

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