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Wyszukujesz frazę "nanotube" wg kryterium: Temat


Tytuł:
The pecularities of structure and diffraction by mis fit mixed-layer nanotubes
Autorzy:
Figovsky, O.
Pashin, D.
Khalitov, Z.
Valeeva, D.
Chkanov, A.
Powiązania:
https://bibliotekanauki.pl/articles/411579.pdf
Data publikacji:
2012
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
nanorurki
karbowanie nanorurek
nanotube
goffered nanotube
superlattice
Opis:
The analysis of diffraction by separate mixed-layer goffered nanotube's lattice is offered. Two extreme cases of the large and small size of coherent scattering regions (CSR) in a radial direction are considered. The qualitative explanation of observed diffraction effects is given.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2012, 2; 7-14
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability of finite-size argon thin film coating single wall carbon nanotube
Autorzy:
Kośmider, M.
Dendzik, Z.
Żurek, S.
Górny, K.
Powiązania:
https://bibliotekanauki.pl/articles/1964139.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska
Tematy:
nanotube
molecular dynamics
cluster
thin film
Opis:
The structure and the dynamics of the argon thin film coating (15,4) and (12,12) carbon nanotubes have been studied in a series of molecular dynamic simulations. In the studied temperature regime, the argon atoms in the thin film were well localized. Structural changes and diffusion process inside the argon layers were not been observed. The influence of the chirality and the radius of the nanotube to the cluster properties is also reported.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2009, 13, 3; 187-197
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology Control of One-Dimensional Gallium Nitride Nanostructures by Modulating the Crystallinity of Sacrificial Gallium Oxide Templates
Autorzy:
Ko, Yun Taek
Park, Mijeong
Park, Jingyeong
Moon, Jaeyun
Choa, Yong-Ho
Lee, Young-In
Powiązania:
https://bibliotekanauki.pl/articles/2049246.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
GaN
nanofiber
nanotube
electrospinning
chemical transformation
Opis:
In this study, we demonstrated a method of controllably synthesizing one-dimensional nanostructures having a dense or a hollow structure using fibrous sacrificial templates with tunable crystallinity. The fibrous Ga2O3 templates were prepared by calcining the polymer/gallium precursor nanofiber synthesized by an electrospinning process, and their crystallinity was varied by controlling the calcination temperature from 500°C to 900°C. GaN nanostructures were transformed by nitriding the Ga2O3 nanofibers using NH3 gas. All of the transformed GaN nanostructures maintained a one-dimensional structure well and exhibited a diameter of about 50 nm, but their morphology was clearly distinguished according to the crystallinity of the templates. When the templates having a relatively low crystallinity were used, the transformed GaN showed a hollow nanostructure, and as the crystallinity increased, GaN was converted into a denser nanostructure. This morphological difference can be explained as being caused by the difference in the diffusion rate of Ga depending on the crystallinity of Ga2O3 during the conversion from Ga2O3 to GaN. It is expected that this technique will make possible the tubular nanostructure synthesis of nitride functional nanomaterials.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 3; 709-712
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analytical study on buckling behavior of CNT/polymer composite plates using the first order shear deformation theory
Autorzy:
Peyyala, P. K.
Subba Rao, V. V.
Powiązania:
https://bibliotekanauki.pl/articles/281618.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
buckling
carbon nanotube
composite plates
micromechanics
FSDT
Opis:
Most plates used in engineering structures such as aircraft wings, ship ducts and buildings, although quite capable of resisting tensile loads, are poor in withstanding compression. In order to avoid premature failure under compression, it is important to know buckling behavior of the plate. This article primarily deals with the analytical study of buckling behavior of a carbon nanotube reinforcing polymer composite plates based on the first order shear deformation theory by employing Mori-Tanaka micromechanics approach to obtain elastic properties. In this investigation, an attempt is made for evaluating the effect of plate thickness, CNT volume fraction, stacking sequence and CNT radii on the buckling of plates.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 71-79
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of the properties of ablative composites with carbon and MMT nanofiller reinforcement
Autorzy:
Szczepaniak, R.
Czubak, K.
Przybyłek, P.
Stabryn, S.
Powiązania:
https://bibliotekanauki.pl/articles/245567.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
composite
ablative properties
nanotube
carbon fibre
ablation
Opis:
One of the most important parameters in the selection of composite materials used for the protection of avionics instruments exposed to high temperatures are ablative properties. They constitute the main criterion in determining the composition and thickness of the protective material. In this article, the authors determine the ablative properties of a polymer matrix with carbon reinforcement and check the effect of using the MMT additive (montmorillonite) on the change in the resistance to the impact of a high heat flux. The tested materials play an important role in the defence, aviation and space industry. Ablative materials are the only ones to protect the rear wall surface from an excessive temperature rise while using a thin insulation wall. For the sake of the research, we prepared a series of samples of the composite produced with epoxy resin LH 145, H 147 hardener, carbon fibre mats and the addition of MMT. The prepared samples were tested on a unique stand in laboratory conditions. The findings obtained from the experimental testing after a detailed analysis were tabulated and presented in the form of graphs. The authors determined the ablative loss of mass of the individual samples, compared their internal temperatures, which had been measured with thermocouples, as well as the temperature on the backside of the sample. In addition, in order to complement the experimental studies of determining the temperature rise on the rear surface, the authors used a thermal imaging camera. Besides, they took photos of different layers of the examined structure, which had been exposed, to a heat stream, by means of a scanning microscope.
Źródło:
Journal of KONES; 2017, 24, 4; 305-312
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CNTFET Based OTRA and its Application as Inverse Low Pass Filter
Autorzy:
Prasad, Dinesh
Tayal, Divyam
Yadav, Ayesha
Singla, Laxya
Haseeb, Zainab
Powiązania:
https://bibliotekanauki.pl/articles/227047.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carbon nanotube (CNT)
Operational Transresistance Amplifier (OTRA)
Opis:
Operational Transresistance Amplifier (OTRA) has been a topic of great interest recently. OTRA has proved itself to be an appropriate device for the analog applications. As MOS scaling suffers from various problems, carbon nanotube field effect transistor (CNTFET) has came into light as one of the brightest alternative for FET (Field Effect Transistors) based devices. This work has introduced a new CNTFET based OTRA which is capable of realising inverse low pass filter using two OTRAs and few passive elements. CNTFET based OTRA has been designed and simulated at 10nm technology node. The working ability of the designed model has been conformed using HSPICE simulation. It is compared with conventional CMOS based OTRA. The comparative analysis has revealed improvement in various performance parameters. The paper also presents how change in number of carbon nanotube in CNTFETs in OTRA circuit affects the transresistance gain and input impedance. The optimized results are also discussed to improve transresistance gain and input impedance. The paper also dealt with the realisation of inverse low pass filter using proposed CNTFET based OTRA.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 4; 665-670
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanofluid flow and heat transfer of carbon nanotube and graphene platelette nanofluids in entrance region of microchannels
Autorzy:
Fuller, N. E.
Liu, J. T. C.
Powiązania:
https://bibliotekanauki.pl/articles/38606230.pdf
Data publikacji:
2020
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
nanofluids
heat transfer
carbon nanotube
graphene nanoplatelettes
Opis:
Suspensions of nano-scale particles in liquids, dubbed nanofluids, are of great interest for heat transfer applications. Nanofluids potentially offer superior thermal conductivity to alternative, pure fluids and are of particular interest in applications where active cooling of power-dense systems is required. In this work, the thermophysical properties of carbon nanotube nanofluids (CNTNf) and those of graphene nanoplatelette nanofluids (GNPNf) as functions of particle volume fraction are deduced from published experiments. These properties are applied to a perturbative boundary layer model to examine how the velocity and temperature profiles (and correspondingly shear stress and surface heat transfer) vary with the nanoparticle concentration in the entrance region of microchannels. Findings of this modeling effort indicate that both shear stress and heat transfer in GNPNf increase with increasing particle concentration. The normalized increase in shear stress is approximately twice that for heat transfer as a function of the GNP particle concentration. Interestingly, CNTNf shows anti-enhancement heat transfer behaviour; an increasing concentration of CNT nanoparticles is associated with both an increase in shear stress and a decrease in the surface heat transfer rate.
Źródło:
Archives of Mechanics; 2020, 72, 4; 355-379
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of carrageenan/multi-walled carbon nanotube hybrid hydrogel nanocomposite for adsorption of crystal violet from aqueous solution
Autorzy:
Hosseinzadeh, H.
Powiązania:
https://bibliotekanauki.pl/articles/780038.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
carrageenan
hydrogel
nanocomposite
carbon nanotube
adsorption
crystal violet
Opis:
A novel polysaccharide-based hydrogel nanocomposite was prepared using grafting of acrylic acid (AA) on to kappa-carrageenan (κC) by incorporating multi-walled carbon nanotube (MCNT). In fact, MCNTs were used as nano-sized reinforcements in the synthesized nanocomposite. Spectroscopy together with morphology proved relatively strong κC-MCNT interaction. Besides, the swelling behavior of the nanocomposite hydrogel was studied. The results showed that in the presence of MCNTs, the equilibrium swelling capacity was decreased. This can be attributed to cross-linking role and hydrophilicity nature of MCNTs. The adsorption performance of hydrogel nanocomposite was also investigated for the removal of crystal violet (CV) as a cationic dye. The effects of some important parameters such as MCNT concentration, pH and contact time on the uptake of CV solution were studied. Equilibrium adsorption isotherm data of the hydrogel exhibited better fit to the Langmuir than to the Freundlich isotherm model. According to this model, the maximum adsorption capacity of κC-based hydrogel nanocomposite was found to be 118 mg . g–1.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 2; 70-76
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on mechanical properties of PE/CNT composites
Autorzy:
Najipour, A.
Fattahi, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/279240.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
nanocomposite
carbon nanotube
polyethylene
injection molding
mechanical properties
Opis:
High density polyethylene/carbon nanotube composites have been produced for investigations. Four CNT volume fractions and two injection pressures were considered. According to the Taguchi approach, eight experiments were designed. The effect of the carbon nanotubes weight fraction and injection pressure on hardness and impact strength of nanocomposite samples were investigated. The results showed that the effect of the carbon nanotube weight fraction on hardness and impact strength of nanocomposite samples was much higher than the effect of injection pressure. By adding 1%wt (weight) carbon nanotube into the polymer, the impact strength and hardness of the samples improved by 74% and 47%, respectively
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 2; 719-726
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving crashworthiness by damping vibrations in cfrp composite structures using carbon nanotubes springs
Autorzy:
Ranjan, K.
Powiązania:
https://bibliotekanauki.pl/articles/950116.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
carbon nanotube springs
CFRP
piezoelectric substance
impact
crashworthiness
Opis:
Carbon nanotubes have tensile strength approximately 30 times higher than the conventional steel. Moreover theoretically these CNT moulded into springs can store potentially 1000 times more energy than steel. Carbon nanotubes have excellent damping characteristics, which is possibly due to interfacial friction between the carbon nanotubes and the polymer resins and also because of large surface area over given specific mass. There applications are still far from reality. But here in this paper I will try to bring the CNT springs to a new application to improve the crashworthiness of a car may it be a formula one or a supercar whose chassis is moulded out of Carbon Fiber Reinforced Plastic (CFRP). These springs combined with piezoelectric substance can give tremendous improvement in driver’s safety during collisions. Here I have tried to combine the mechanical strength of Carbon nanotube with best suitable piezoelectric material to derive a new property which will transform impact energy into electrical energy and hence utilize it for driver’s protection. In the paper I have studied various piezoelectric materials, their bonding and behaviour with carbon atoms. I have tried to generate a possible stable structure theoretically which can withstand high impact as well as generate enough potential energy for driver to be safe during the impact.
Źródło:
Journal of KONES; 2013, 20, 2; 343-348
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiobjective Performance Investigation of CNT Coated HSS Tool Under the Response Surface Methodology Platform
Autorzy:
Chandru, Manivannan
Selladurai, Velappan
Venkatesh, Chenrayan
Powiązania:
https://bibliotekanauki.pl/articles/2049740.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carbon nanotube
RSM
cutting forces
cutting tooltip temperature
tool wear
Opis:
The present research employs the statistical tool of response surface methodology (RSM) to evaluate the machining characteristics of carbon nanotubes (CNTs) coated high-speed steel (HSS) tools. The methodology used for depositing carbon nanotubes was Plasma-Enhanced Chemical Vapor Deposition (PECVD). Cutting speed, thickness of cut, and feed rate were chosen as machining factors, and cutting forces, cutting tooltip temperature, tool wear, and surface roughness were included as machining responses. Three-level of cutting conditions were followed. The face-centered, Central Composite Design (CCD) was followed to conduct twenty number of experiments. The speed of cutting and rate of feed have been identified as the most influential variables over the responses considered, followed by the thickness of cut. The model reveals the optimized level of cutting parameters to achieve the required objectives. The confirmation experiments were also carried out to validate the acceptable degree of variations between the experimental results and the predicted one.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 2; 627-635
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of heat transfer during pool boiling on minifins surface coated with carbon nanotubes
Autorzy:
Strąk, E.
Pastuszko, R.
Kłosowiak, R.
Urbaniak, R.
Powiązania:
https://bibliotekanauki.pl/articles/175588.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pool boiling
carbon nanotube
heat transfer coefficient
power
electronic cooling
Opis:
The article describes the study of heat transfer during pool boiling on minifins surface coated with nanostructure. This is a molecular level technology used in engineering or mechanical factory. A surface with carbon nanotubes (CNTs) is highly effective in reducing the superheat incipience and enhancing both the heat flux and heat transfer coefficient. The paper focuses on the comparison of the surfaces, on which pool boiling heat transfer occurs, i.e., on minifins coated with carbon nanotubes (MF+N) with surfaces formed by sintering the woven copper wire mesh to the minifins tips (MF+M) and with plain minifins surface (MF). The experiments were carried out for two boiling fluids: water and ethyl alcohol. The purpose of the presented study was to find out which of those tested surfaces and fluids could be the best alternative for use in the cooling of electronic devices and which surfaces could be used as thermosyphon or heat pipe evaporator.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2015, 128; 59-72
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of crack resistance in epoxy/boron nitride nanotube nanocomposites based on multi-scale methodInvestigation of crack resistance in epoxy/boron nitride nanotube nanocomposites based on multi-scale method
Autorzy:
Hemmatian, Hossein
Zamani, Mohammad Reza
Jam, Jafar Eskandari
Powiązania:
https://bibliotekanauki.pl/articles/280181.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
boron nitride nanotube
epoxy
fracture modes
finite element model
multi-scale method
Opis:
Boron nitride nanotubes (BNNTs) possess superior mechanical, thermal and electrical properties and are also suitable for biocomposites. These properties make them a favorable reinforcement for nanocomposites. Since experimental studies on nanocomposites are timeconsuming, costly, and require accurate implementation, finite element analysis is used for nanocomposite modeling. In this work, a representative volume element (RVE) of epoxy/BNNT nanocomposites based on multi-scale modeling is considered. The bonds of BNNT are modeled by 3D beam elements. Also non-linear spring elements are employed to simulate the van der Waals bonds between the nanotube and matrix based on the Lennard- -Jones potential. Young’s and shear modulus of BNNTs are in ranges of 1.039-1.041 TPa and 0.44-0.52 TPa, respectively. Three fracture modes (opening, shearing, and tearing) have been simulated and stress intensity factors have been determined for a pure matrix and nanocomposite by J integral. Numerical results indicate that by incorporation of BNNT in the epoxy matrix, stress intensity factors of three modes decrease. Also, by increasing the chirality of BNNT, crack resistance of shearing and tearing modes are enhanced, and stress intensity factor of opening mode reduced. BNNTs bridge the crack surface and prevent crack propagation.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 1; 207-219
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigating of a wide range of concentrations of multi-walled carbon nanotubes on germination and growth of castor seeds (Ricinus communis L.)
Autorzy:
Fathi, Z.
Khavari Nejad, R.-A.
Mahmoodzadeh, H.
Satari, T.N.
Powiązania:
https://bibliotekanauki.pl/articles/65867.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
concentration
multi-walled carbon nanotube
germination
growth
castor oil
seed
Ricinus communis
Euphorbiaceae
Opis:
Carbon nanotubes act as regulators of plant germination and growth and are able to change the morphology and physiology of plant cells. The castor plant (Ricinus communis L.) belongs to the Euphorbiaceae family and is a very important medicinal plant. The aim of this study was to investigate the effect of 10 different concentrations of multi-walled carbon nanotubes (MWCNTs) (2, 5, 10, 20, 50, 75, 100, 125, 250 and 500 μg · ml–1) alongside the control under laboratory conditions on the germination and growth of castor seedlings. The results demonstrated that the maximum percentage of germination (96.7%) and relative germination percentage (100%) were found in the concentrations of 50 and 100 μg · ml–1, respectively, and the highest germination rate (53.3%) and the mean germination time (4.6 days) was seen in the concentration of 75 μg · ml–1. However, no statistically significant differences were found between the different concentrations in any of the germination factors. In the concentration of 100 μg · ml–1, there was a significant increase in the seedling vigor index I (400) when compared with the concentrations of 5 and 10 μg · ml–1. The maximum seedling vigor index II (11.3) was found in the concentration of 100 μg · ml–1 and was significantly different from the control and all applied concentrations. The length of radicle in the 100 and 125 μg · ml–1 had a significant increase when compared with the control and the concentrations of 10 and 50 μg · ml–1. The maximum seedling length (4.6 cm) was seen in the concentration of 100 μg · ml–1 where there was a significant increase with 10 μg · ml–1. Moreover, in the 100 μg · ml–1 concentration, the largest number of rootlets (8.6) was seen and when compared with the control and concentrations of 5, 10 and 50 μg · ml–1, there was a statistically significant increase. The maximum wet weight (0.3 g) and dry weight (0.1 g) of seedlings were obtained in the concentration of 100 μg · ml–1 and when compared with the control, there was a significant increase. It was found that in all factors related to the growth of seedlings, the concentrations of 10 and 50 MWCNTs had an inhibitory effect on the response index. The MWCNTs concentration of 100 μg · ml–1 was considered as the optimum concentration in the growth stage of castor seedlings.
Źródło:
Journal of Plant Protection Research; 2017, 57, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of selected aspects of a tank gassing-up process on board liquefied petroleum gas carrier. Part I
Autorzy:
Wieczorek, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/1845464.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
convective heat transfer
Reynolds number
nanofluid
single
wall
carbon
nanotube
SWCNT
laminar flow
Opis:
The paper is a thermodynamics analysis of the removal of any inert gas from the tank using the vapors of any liquefied petroleum gas cargo (called cargo tank gassing-up operation). For this purpose, a thermodynamic model was created which considers two boundary cases of this process. The first is a ‘piston pushing’ of inert gas using liquefied petroleum gas vapour. The second case is complete mixing of both gases and removal the mixture from the tank to the atmosphere until desired concentration or amount of liquefied petroleum gas cargo in the tank is reached. Calculations make it possible to determine the amount of a gas used to complete the operation and its loss incurred as a result of total mixing of both gases.
Źródło:
Archives of Thermodynamics; 2021, 42, 2; 43-58
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of convective heat transfer of single wall carbon nanotube nanofluid laminar flow inside a circular tube
Autorzy:
Saeed, Farqad Rasheed
Jasim, Marwah A.
Mahmood, Natheer B.
Jaffar, Zahraa M.
Powiązania:
https://bibliotekanauki.pl/articles/1845470.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
convective heat transfer
reynolds number
nanofluid
single
wall
carbon
nanotube
SWCNT
laminar flow
Opis:
This study presents the behavior of a single wall carbon nanotube (SWCNT)/water nanofluid for convective laminar flow inside a straight circular pipe heated by a constant heat flux. Five volume fractions of SWCNT were used to investigate their effect on the heat transfer coefficient, Nusselt number, temperature distribution and velocity field in comparison with pure water flow. One model for each property was tested to calculate the effective thermal conductivity, effective dynamic viscosity, and effective specific heat of the SWCNT/water mixture. The models were extracted from experimental data of a previous work. The outcomes indicate that the rheological behavior of SWCNT introduces a special effect on the SWCNT/water properties, which vary with SWCNT volume fraction. The results show an improvement in the heat transfer coefficient with increasing volume fraction of nanoparticles. The velocity of SWCNT/water nanofluid increased by adding SWCNT nanoparticles, and the maximum increase was registered at 0.05% SWCNT volume fraction. The mixture temperature is increased with the axial distance of the pipe but a reduction in temperature distribution is observed with the increasing SWCNT volume fraction, which reflects the effect of thermophysical properties of the mixture.
Źródło:
Archives of Thermodynamics; 2021, 42, 2; 103-119
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wybranych rodzajów wielościennych nanorurek węglowych (MWCNT) na deformowalną warstwę fosfolipidową na powierzchni wody
Influence of different multi-walled carbon nano-tubes (MWCNTs) on deformable phospholipid film on aqueous surface
Autorzy:
Kondej, D.
Sosnowski, T. R.
Powiązania:
https://bibliotekanauki.pl/articles/2073380.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
nanorurki węglowe
surfaktant płucny
inhalacja
efekty powierzchniowe
carbon nanotube
lung surfactant
inhalation
interfacial effects
Opis:
Przedstawiono i omówiono wyniki badania wpływu nanorurek węglowych o różnej charakterystyce na dynamiczne właściwości powierzchniowo czynne mono warstwy fosfolipidowej modelującej surfaktant płucny na powierzchni woda-powietrze. Stwierdzono zaburzenie mechanicznych cech powierzchni międzyfazowej w postaci zmian jej ściśliwości. Efekty te zależą od rodzaju nanorurek (w tym zwilżalności i powierzchni właściwej) oraz ich stężenia. Potwierdzono obserwowaną we wcześniejszych badaniach specyficzną zależność parametrów reologicznych od stężenia cząstek, którą można tłumaczyć agregacją nanorurek po przekroczenia stężenia granicznego.
Experimental investigations of MWCNTs influence on dynamic surface-active properties of phospholipid monolayer used as a functional model of lung surfactant at air-water interface are presented. Modification of mechanical properties of the interface was detected in a form of surface compressibility changes. The observed effects are dependent on MWCNTs concentration and their properties (including wettability and specific surface area). The particular relationship between surface rheological parameters and particle concentration was detected suggesting the effect of carbon nanotubes aggregation at a certain concentration level.
Źródło:
Inżynieria i Aparatura Chemiczna; 2017, 6; 205--207
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication of Titanium dioxide nanotube photo-electrodes in different electrolyte mixtures and the impacts on their characteristics and photo-catalytic abilities under visible light
Autorzy:
Liu, M-T.
Zhang, J.
Wang, B.
Powiązania:
https://bibliotekanauki.pl/articles/780075.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
TiO2
anodizing
electrolytes
Nanotube arrays
photo-catalysis
water pollution
water treatments
Rhodamine B
Opis:
TiO2  nanotube arrays were fabricated using electrochemical anodization of titanium foils, where different types of electrolytes were tested to determine conceptual choice for nanotubes fabrication. These electrolytes are 1M (NH4)2SO4  containing 0.5% wt NH4F, 1M Na2SO4  containing 0.5% wt NH4F, 1M NaF containing 0.5% wt (NH4)2SO4  and a mixture of water: ethylene glycol 1:9 containing 0.5% wt NH4F. The foils were marked as EG type (Ethylene Glycol), AS type (Ammonium sulfate), SS type (sodium sulfate) and SF type (sodium fluoride). The photocatalytic capabilities and characterization of the fabricated NTAs were analyzed using SEM, XRD, and DRS. The degradation ratio of designated organic pollutants (Rhodamine B) was analyzed. The obtained results have proven that foils fabricated using Ethylene glycol have significant photocatalytic abilities, with a degradation ratio of EG-SS-SF-AS types being 80% to 85%, 70% to 80%, 70% to 75% and 52% to 55%, respectively.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 1; 34-40
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular order and dynamics of 5CB liquid crystals in confined space - computer simulation
Autorzy:
Gwizdała, W.
Gburski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1940712.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska
Tematy:
liquid crystal
5CB
carbon nanostructure
nanotube
graphene
computer simulation
MD
second rank order parameter
Opis:
We studied the dynamical and structural properties of an important nematic 4-n-pentyl-4’-cyanobiphenyl (5CB) mesogen placed near carbon allotropes (graphene, nanotube), using modeling and molecular dynamics simulations (MD). Every investigated nanosystem (a free cluster of 5CB, a 5CB cluster confined in a single-walled carbon nanotube, 5CB mesogens located between two graphene sheets, a 5CB thin layer on a single-walled carbon nanotube, a thin layer of a 5CB molecules near graphene plane) contains a liquid crystal cluster consisting of 5CB molecules (22–98 molecules). We also performed a computer experiment for a 5CB bulk sample (196 5CB mesogens) with periodic boundary conditions. The following observables were calculated for several temperatures: mean square displacement, radial distribution function and second rank order parameter of 5CB clusters. The obtained results from MD simulations were discussed and compared with the experimental data.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 1; 35-64
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free vibration analysis of thick disks with variable thickness containing orthotropic-nonhomogeneous material using finite element method
Autorzy:
Zafarmand, H.
Kadkhodayan, M.
Powiązania:
https://bibliotekanauki.pl/articles/279473.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
free vibration
carbon nanotube
functionally graded material
thick disk
variable thickness
graded finite element method
Opis:
Free vibration analysis of thick functionally graded nanocomposite annular and solid disks with variable thickness reinforced by single-walled carbon nanotubes (SWCNTs) is presented. Four types of distribution of uniaxial aligned SWCNTs are considered: uniform and three kinds of functionally graded (FG) distribution through radial direction of the disk. The effective material properties of the nanocomposite disk are estimated by a micro mechanical model. The axisymmetric conditions are assumed and employing the graded finite element method (GFEM), the equations are solved. The solution is considered for four different thickness profiles, namely constant, linear, concave and convex. The achieved results show that the type of distribution and volume fraction of CNTs and thickness profile have a great effect on normalized natural frequencies.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 4; 1005-1018
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterisation of PSA/CNT Composites and Fibres
Wytwarzanie i charakteryzacja kompozytów polisulfonamidowych z udziałem nanorurek węglowych oraz wytworzonych z nich włókien
Autorzy:
Chen, Z.
Xin, B.
Wu, X.
Wang, X.
Du, W.
Powiązania:
https://bibliotekanauki.pl/articles/232490.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
polysulfonamide
nanorurki węglowe
nanokompozyty
własności termiczne
przewodność elektryczna
carbon nanotube
nanocomposites
thermal property
electrical conductivity
Opis:
In this paper, polysulfonamide/carbon nanotube (PSA/CNT) composite solutions with different CNT contents were prepared using the physical blending method. Corresponding composite fibers were extruded and fabricated through a set of wet spinning units, and composite membranes were prepared by the spin-coating method. The PSA/CNT composite fibers and membranes were characterised by means of SEM, FTIR and XRD among others. The mechanical, thermal and electrical properties were also analysed in this study. The experimental results show that CNT at low contents can be distributed homogeneously in the PSA matrix. Furthermore the molecular structure and chemical composition of PSA does not undergo an obvious change. Crystallisation in the PSA can be promoted at low CNT contents because the nano-particles can act as a nucleation agent. Moreover the electrical conductivity of PSA can be improved significantly by the blending of CNT.
Przygotowano szereg zestawów polisulfonamidu i różnej ilości nanorurek węglowych. Z przygotowanego kompozytu wyprodukowano włókna i folie, które zostały scharakteryzowane przez skaningową mikroskopię elektronową, spektroskopię w podczerwieni i dyfrakcję rentgenowską. Analizowano również właściwości mechaniczne, przewodność cieplną i elektryczną otrzymanych próbek. Wyniki wskazują, że przy małym stężeniu nanorurek węglowych mogą one być rozprowadzone jednorodnie w całej matrycy; struktura molekularna i właściwości matrycy PSA nie ulegają zmianie; krystalizacja w matrycy PSA inicjowana jest przez nanorurki; przewodność elektryczna kompozytu zależy w dużym stopniu od ilości dodanych nanorurek.
Źródło:
Fibres & Textiles in Eastern Europe; 2012, 5 (94); 21-25
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology and selected properties of NR/BR/CNT nanocomposites – effect of ethanol-assisted mixing
Struktura i wybrane właściwości nanokompozytów NR/BR/CNT – wpływ mieszania wspomaganego etanolem
Autorzy:
Zhang, Juzheng
Gu, Zheng
Meng, Chao
Wang, Jianfa
Sui, Jinyong
Powiązania:
https://bibliotekanauki.pl/articles/24202824.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
natural rubber
butadiene rubber
carbon nanotube
nanocomposites
kauczuk naturalny
kauczuk butadienowy
nanorurki węglowe
kompozyt
dyspersja
Opis:
Carbon nanotubes (CNT) and ethanol-assisted mixing were used to obtain composites based on a mixture of natural rubber and butadiene rubber (NR/BR 80/20). The structure of the composites was determined by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal aging tests were also carried out and the vulcanization process was characterized. SEM confirmed the homogeneous dispersion of CNTs in the polymer matrix. Improvements in tensile and tear strength as well as thermal stability were also achieved.
Do otrzymywania kompozytów na bazie mieszaniny kauczuku naturalnego i butadienowego (NR/BR 80/20) zastosowano nanorurki węglowe (CNT) i mieszanie wspomagane etanolem. Strukturę kompozytów określono za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FTIR) oraz skaningowej mikroskopii elektronowej (SEM). Przeprowadzono również badania starzenia termicznego oraz scharakteryzowano proces wulkanizacji. Metodą SEM potwierdzono jednorodną dyspersję CNT w osnowie polimerowej. Uzyskano również poprawę wytrzymałości na rozciąganie i rozdzieranie oraz stabilności termicznej.
Źródło:
Polimery; 2023, 68, 5; 251--258
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electromagnetic Wave Absorbing Properties of Cotton Fabric with Carbon Nanotubes Coating
Właściwości pochłaniania fal elektromagnetycznych tkaniny bawełnianej z powłoką z nanorurek węglowych
Autorzy:
Zou, Lihua
Shen, Jiahui
Xu, Zhenzhen
Ruan, Fangtao
Qiu, Yiping
Liu, Zhi
Powiązania:
https://bibliotekanauki.pl/articles/232586.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
carbon nanotube
electromagnetic wave
absorbing
coating
cotton fabric
nanorurka węglowa
fala elektromagnetyczna
pochłanianie
powłoka
tkanina bawełniana
Opis:
In order to endow cotton fabric with the electromagnetic shielding property while preserving comfort and softness, carbon nanotubes (CNTs) were coated onto NaOH pretreated fabrics via a binder-free dip-coating approach. Scanning electron microscopy (SEM) and Infrared spectroscopy were utilised to investigate the surface morphology and modification of the CNT functionalised fabrics. The effects of the number of dip-coatings, the concentration of carbon nanotubes, and the impregnation temperature on electrical conductivity, electromagnetic (EM) shielding effectiveness (SE), and wave absorbing efficiency of cotton fabrics were evaluated, respectively. The SE value of the CNT functionalised cotton fabrics increased with the dip-coating time and reached 16.5 dB after CNT dip-coating ten times, which indicates that 97.76% of the electromagnetic wave was shielded. Meanwhile, by adding layers of stacking fabrics, the SE of CNT coated fabrics was further improved to 26.4 dB. The shielding mechanism was also studied by comparing its reflection and absorption behaviour, which demonstrates that 65.7% of the electromagnetic wave was absorbed.
Aby nadać tkaninie bawełnianej właściwości ekranowania elektromagnetycznego przy jednoczesnym zachowaniu komfortu i miękkości, najpierw zastosowano obróbkę tkaniny z zastosowaniem NaOH, a następnie nałożono na nią powłokę z nanorurek węglowych (CNT). Za pomocą skaningowej mikroskopii elektronowej (SEM) i spektroskopii w podczerwieni zbadano morfologię powierzchni tkanin funkcjonalizowanych CNT. Oceniono wpływ liczby powłok zanurzeniowych, stężenia nanorurek węglowych i temperatury impregnacji na przewodność elektryczną, skuteczność ekranowania elektromagnetycznego (EM) (SE) oraz efektywność pochłaniania fal przez tkaniny bawełniane. Stwierdzono, że wartość SE funkcjonalizowanych tkanin bawełnianych CNT wzrastała wraz z czasem powlekania zanurzeniowego i osiągnęła 16.5 dB po dziesięciokrotnym powlekaniu zanurzeniowym CNT, co wskazało, że 97.76% fali elektromagnetycznej było ekranowane. Poprzez dodanie warstw tkanin, współczynnik SE tkanin powlekanych CNT został dodatkowo poprawiony do 26,4 dB. Zbadano również mechanizm ekranowania, porównując jego właściwości odbijania oraz pochłaniania i stwierdzono, że 65.7% fali elektromagnetycznej zostało zaabsorbowane.
Źródło:
Fibres & Textiles in Eastern Europe; 2020, 5 (143); 82-90
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostic of the Decomposition of Sulphur Hexafluoride (SF₆) in Gas-Insulated Equipment, Due to Partial Discharges, Using Hollow Carbon Nanotubes
Autorzy:
Chenaf, T.
Zegnini, B.
Benghia, A.
Powiązania:
https://bibliotekanauki.pl/articles/1031774.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
Gas insulated switchgear
decomposition gases
carbon nanotube
Material Studio (MS)
DMol3 module
adsorption
graphene sheets.
Opis:
Sulphur hexafluoride, SF₆ gas has excellent physical and chemical properties and insulation arc extinction performance. It has been widely used in electric power systems and other electrical equipment due to such advantages, as compact size and high reliability. SF₆, can be decomposed into different gases, when the equipment exhibits arc discharge, local heating of contactor, and partial discharge. It is important to detect decomposition of insulating gas SF₆, caused by partial discharges for gas-insulated switchgear. Partial discharge in gas-insulated switchgear can lead to the generation of multiple decomposition products of SF₆, and the detection and analysis of these decomposition products is important for fault diagnosis. The detection of decomposition components is needed to maintain on-line running state monitoring. Recently, interest in carbon nanotubes has been rapidly growing in various scientific and engineering fields, because of their faster response, higher sensitivity, lower operating temperature and a wider variety of detectable gas. In this paper, a molecular dynamics simulation software package, Materials Studio, is used to model accurately the processes by which single-walled carbon nanotubes could detect studied gases. All calculations were performed using the DMol³module of the Materials Studio. We compute the preferential adsorption sites, bonding configurations, and adsorption geometry for molecular adsorption. Results of analysis of electrical characteristics reveal that SWCNTs show different responses to the decomposed gases.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 1176-1180
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of cement matrixes with dispersion of multilayer carbon nanotubes
Modifikacija cementhykh matric dispersiejj mnogoslojjnykh uglerodnykh nanotrybok
Autorzy:
Yakovlev, G.
Pervushin, G.
Fedorova, G.
Maeva, I.
Pudov, I.
Korzhenko, A.
Keriene, J.
Powiązania:
https://bibliotekanauki.pl/articles/793569.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
carbon nanotube
dispersion
calcium hydrosilicate
frost resistance
compact structure
Portland cement
cement stone
microstructure
thermal analysis
cement matrix
Opis:
The concrete with compact structure on the basis of Portland cement modified by the dispersion of multilayer carbon nanotubes GraphistrengthTM by Arkema is investigated. The change in the structure of cement stone in the process of concrete setting and hardening when introducing carbon nanotubes into the concrete composition is observed.
Исследован бетон плотной структуры на основе портландцемента, модифицированный дисперсией многослойных углеродных нанотрубок GraphistrengthTM, производимых корпорацией «Аркема». Установлено изменение структуры цементного камня в процессе гидратации и твердения при введении углеродных нанотрубок в состав бетона.
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 3
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł

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