scholarly journals Conductive concrete made from recycled carbon fibres for self-heating and de-icing applications in urban furniture

2020 ◽  
Vol 70 (339) ◽  
pp. 223
Author(s):  
G. Faneca ◽  
T. Ikumi ◽  
J. M. Torrents ◽  
A. Aguado ◽  
I. Segura
Keyword(s):  
Carbon Fibers ◽  
Dense Matrix ◽  
Carbon Fibres ◽  
Industrial Facilities ◽  
Self Heating ◽  
Heating Performance ◽  
Heating Capacity ◽  
Efficient Heat Transfer ◽  
Real Scale ◽  
Heated Element

This paper presents a broad experimental study performed at laboratory and industrial facilities to develop conductive concrete for self-heating and de-icing applications in urban furniture. Self-heating capacity is achieved by the application of electric current through a highly dense matrix containing recycled carbon fibers and graphite flakes. Prisms and slabs were fabricated with two different conductive concretes and electrode con­figurations to characterize the electrical properties and heating performance. Finally, 3 benches with different electrode disposals were fabricated to assess the heating capacity in real-scale applications. The results presented indicate promising results about the use of recycled carbon fibers for electrothermal concrete applications and identify the electrode configuration that allows the most efficient heat transfer and reduction of temperature gradients within the heated element. Real-scale tests show that the current technology developed is potentially applicable at de-icing applications in climates where temperatures remain within the range of -3 or -5 ºC.

scholarly journals Metallization of Carbon Fibers by Double and Triple Copper Composition

2015 ◽  
Vol 16 (1) ◽  
pp. 185-192
Author(s):  
H.O. Sirenko ◽  
M.B. Skladanyuk ◽  
L.M. Soltys
Keyword(s):  
Crystal Structure ◽  
Carbon Fibers ◽  
Copper Content ◽  
Coating Process ◽  
Carbon Fibres ◽  
Application Technology ◽  
Surface Layers ◽  
Foundations Of Physics ◽  
Theoretical Foundations ◽  
Layer Coating

The theoretical foundations of physics and chemistry and application technology of single- and double-layer coating based on Cu0+Cu2O, Ni0+P, Pb0 on the surface of carbonated fibers have been reviewed. The changes of surface layers crystal structure of carbon fibres in the course of copper-plating have been investigated. The metallic coating process using modified formaldehyde and zinc technology was realized. It is established that copper content in copper – copper oxide increases when using two-layer alternately modified formaldehyde and zinc methods.

Thermal Expansion of Composite System Epoxy Resin/Recycled Carbon Fibers

2020 ◽  
Vol 994 ◽  
pp. 162-169
Author(s):  
Štěpánka Dvořáčková ◽  
Dora Kroisová
Keyword(s):  
Experimental Study ◽  
Thermal Expansion ◽  
Epoxy Resin ◽  
Carbon Fibers ◽  
Composite System ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Carbon Fibres ◽  
Sample Matrix ◽  
Composite Systems

This experimental study deals with the problematics of thermal expansion α [10-6/K] of the composite systems based on recycled carbon fibres reinforced epoxy resin. The epoxy resin CHS – EPOXY 520 (EPOXY 15), cured with the hardener P11 (Districhem, s.r.o.), was chosen as a sample matrix. Recycled carbon fibres with a diameter of 7 μm and a length of 100 μm (Easy Composites Ltd.) were the filler. In the experiment, samples with the fulfilment of 10, 20, 40, 60, 80, 90 and 100 phr were prepared. The samples were being poured into silicone molds, cured at an overpressure of 0.7 MPa and a temperature of 23 ± 2 °C for 24 hours. A thermomechanical analyzer was used to determine the thermal expansion of composite systems. The addition of recycled carbon fibers to epoxy resin can reduce the coefficient of linear thermal expansion at 20°C in half, from the original α = 45 to 55 × 10-6/K for non-filled epoxy resin to α = 25 to 27 × 10-6/K for filled epoxy resin. Optimal filling is at the level of 40 phr, with higher filling there is no further reduction of the linear thermal expansion coefficient.

Studies Regarding the Influence of Loading Force on the Wear Intensity in Case of Polymeric Composite Materials Reinforced with Short Carbon Fibers

2014 ◽  
Vol 1036 ◽  
pp. 36-39
Author(s):  
Radu Caliman
Keyword(s):  
Composite Materials ◽  
Carbon Fibers ◽  
Research Work ◽  
Polymeric Composite ◽  
Wear Intensity ◽  
Tantalum Carbide ◽  
Carbon Fibres ◽  
Polymeric Composite Materials ◽  
Pin On Disc ◽  
Short Carbon

This paper presents a study of the wearing behaviour of polymeric composite materials reinforced with short carbon fibres. Reinforces carbon fiber materials are more effective if refer to specific properties per unit volume compared to conventional isotropic materials. The composite materials used in this research work are obtained combining epoxy with short carbon fibres with titanium carbide and tantalum carbide in order to investigate the wearing intensity of the obtained composites. Varying the percent of epoxy from 29,35% to 43,92% and the percent of short carbon fibres from 35,43% to 53,70%, two different composite materials are obtained and tested. Wearing intensity tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured maintaining constant the rotational speed (14 m/s) and time (120s) and varying the pin-on-disc pressing force: 4, 8 and 12 daN. The pressing load had different effects on the wearing behaviour of the composite coating in dry friction condition. With low percent of epoxy and high percent of carbon fibers the wearing intensity is touching the highest value and gradually decreases with the increasing load, while in low percent of carbon fibers the wearing intensity became larger gradually along with the load increasing.

Effect of Refrigerant Flow Control on the Heating Performance of a Variable-Speed Heat Pump Operating at Low Outdoor Temperature

2005 ◽  
Vol 127 (2) ◽  
pp. 277-286 ◽  
Author(s):  
Bong H. Kim ◽  
Dennis L. O’Neal
Keyword(s):  
Flow Control ◽  
Heat Pump ◽  
Performance Enhancement ◽  
Capillary Tube ◽  
Opening Angle ◽  
Variable Speed ◽  
Outdoor Temperature ◽  
Heating Performance ◽  
Heating Capacity ◽  
Expansion Valve

An experimental study was conducted to investigate the effect of electronic flow control on the performance of a variable-speed heat pump. A heat pump with two different expansion devices (capillary tube and electronic expansion valve) was tested in a psychrometric calorimeter over a range of outdoor temperatures from −15 to 7°C. Heat pump performance was first optimized with respect to charge for each expansion device through cycle-matching tests. Parametric tests also were conducted by changing compressor speed and opening angle for the electronic expansion valve at each outdoor temperature. The refrigeration cycle characteristics of the electronic valve were illustrated using pressure-enthalpy diagrams. Performance enhancement was also analyzed in terms of superheat, heating capacity, and energy efficiency ratio (EER). Comparison of the capillary tube and electronic valve indicated that the superheat significantly improved when using the electronic valve. Also, unit showed larger heating capacity and EER with the electronic valve than with the capillary tube except when the compressor speed was above 95 Hz. Enhancement of heating performance became larger as outdoor temperature decreased.

Methodology for Optimizing the Heating Capacity of Heat-Source Equipments in Double-Energy Radiator Heating System

2012 ◽  
Vol 170-173 ◽  
pp. 2743-2746
Author(s):  
Feng Li ◽  
Zhe Tian ◽  
Qiang Fu ◽  
Qian Ru Li
Keyword(s):  
Heat Source ◽  
Operating Cost ◽  
Heating System ◽  
Heat Pumps ◽  
Heating Period ◽  
Heating Performance ◽  
Heating Capacity ◽  
Minimum Operating ◽  
Optimal Heating ◽  
Sewage Source

The double-energy heating system studied in this paper is consisted of centrifugal sewage-source heat pumps and gas boilers. As the grade and price of the two kinds of energy are different, the heating capacity of the heat-source equipments would have a directly impact on the energy consumption and operating cost of the system. In order to obtain the optimal heating capacity of the heat-source equipments, the calculation models on equipments utilized in this system are firstly established, and then different combination patterns of the heat-source equipments were analyzed on the basis of minimum operating cost, finally, the optimal heating capacity of the heat-source equipments and the heating performance factor (HPF) of the system in different outdoor temperatures were obtained, the results indicate the average HPF of the system in the heating period is 3.57. The method and results provide reference for scientific design of the double-energy heating system.

scholarly journals Investigation on the flexural properties of nanofillers loading on the Jute/Carbon/PLA nanocomposites

2020 ◽  
Vol 14 (4) ◽  
pp. 7424-7433
Author(s):  
Nur Aqilah Sairy ◽  
Norkhairunnisa Mazlan ◽  
Mohamad Ridzwan Ishak ◽  
Nik Noriman Zulkepli
Keyword(s):  
Polymer Nanocomposites ◽  
Carbon Fibers ◽  
Flexural Modulus ◽  
Polymer Nanocomposite ◽  
Fiber Reinforced Polymer ◽  
Carbon Fibres ◽  
Nanocomposite Fiber ◽  
Reinforced Polymer ◽  
Flexural Analysis ◽  
Fractured Surface

Presence of fibers and fillers in a composite can be an efficient way to arrest crack either at macro or micro levels. In this work, woven jute and carbon fibers were arranged alternately in PLA (Polylactic Acid) nanocomposite. Graphene or nanoclay was embedded into PLA matrix to make polymer nanocomposite. Fiber reinforced polymer nanocomposites were prepared by varying the concentration of graphene or nanoclay in the PLA matrix and alternate woven jute/carbon fibers was then bind with the PLA nanocomposite. Influence of graphene or nanoclay concentration and presence of woven fibres in the composite was quantified by flexural analysis. Flexural strength and flexural modulus were found to increase at 3wt% of nanofiller concentration for both graphene/jute/PLA and nanoclay/jute/PLA nanocomposites with increment up to 37% and 31%, respectively. FTIR was used to determine the interaction between PLA and nanofillers. Morphology observation by Scanning Electron Microscopy (SEM) was done to investigate the fractured surface of the hybrid jute/carbon fibres reinforced PLA nanocomposite.

scholarly journals Preparation of boron nitride nanosheet-coated carbon fibres and their enhanced antioxidant and microwave-absorbing properties

RSC Advances ◽  
2018 ◽  
Vol 8 (32) ◽  
pp. 17944-17949 ◽  
Author(s):  
Zhichao Xu ◽  
Yongjun Chen ◽  
Wei Li ◽  
Jianbao Li ◽  
Hui Yu ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Carbon Fibers ◽  
Carbon Fibres ◽  
Microwave Absorbing Properties ◽  
Boron Nitride Nanosheet ◽  
Microwave Absorbing ◽  
Coated Carbon

The coating of BN nanosheets on carbon fibers could enhance the anti-oxidation and microwave absorbing properties of carbon fibers significantly.

SYNERGISTIC EFFECTS OF PLASMA POLYMERIZATION AND COVALENT SURFACE MODIFICATION OF CARBON FIBERS

2021 ◽  
Author(s):  
DANIEL J. EYCKENS ◽  
LACHLAN SOULSBY ◽  
FILIP STOJCEVSKI ◽  
ATHULYA WICKRAMASINGHA ◽  
LUKE C. HENDERSON
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Surface Modification ◽  
Carbon Fibers ◽  
Plasma Polymerization ◽  
Interfacial Shear Strength ◽  
Synergistic Effects ◽  
Interfacial Shear ◽  
Carbon Fibres ◽  
Electrochemical Pretreatment

This work demonstrates the efficacy in performing an electrochemical pretreatment on carbon fibres to improve the effect of plasma polymerization of acrylic acid on these surfaces. Modified samples demonstrated improve physical properties including tensile strength and Young’s modulus, as well as an increase in composite performance as measured by the interfacial shear strength. The electrochemical pretreatment was shown to enhance the advantages observed when coating fibres using plasma polymerization.

scholarly journals Propiedades mecánicas de morteros de cemento con adiciones de fibras de carbono, nanotubos de carbono y grafeno = Mechanical properties of cement mortars with additions of carbon fibres, carbon nanotubes and graphene

2017 ◽  
Vol 3 (3) ◽  
pp. 12
Author(s):  
María Ursúa Goicoechea
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Carbon Fibers ◽  
Carbon Materials ◽  
Carbon Fibres ◽  
Cement Mortars ◽  
Different Types ◽  
Cement Matrices ◽  
Cement Compounds

El carbono es uno de los elementos más abundantes de la naturaleza. Su particular estructura hace que pueda tener hasta cinco tipos distintos de alótropos. Durante los últimos años se han producido grandes avances en el estudio de estos materiales de carbono. Las fibras de carbono (CF), los nanotubos de carbono (CNTs) y el grafeno y óxido de grafeno (GO), en función de su estructura y su escala, presentan unas propiedades notablemente diferenciadas. Este estudio pretende comparar y determinar los efectos de estas características en matrices de cemento. Las características de estos materiales son difíciles de transmitir de forma exacta a los compuestos de cemento y hormigones, principalmente por las dificultades que presentan los nanomateriales en su dispersión. Por ello, los datos obtenidos en distintos estudios muestran resultados muy variables. Sin embargo, se ha demostrado que, para mejoras medias, los nanomateriales resultan ser más eficientes.AbstractCarbon is one of the most abundant elements of nature. Its particular structure has to have up to five different types of allotropes. During the last years there have been great advances in the study of these carbon materials. Carbon fibers (CF), carbon nanotubes (CNT) and graphene and graphene oxide (GO), depending on their structure and scale, have remarkably different properties. This study aims to compare and determine the effects of these characteristics on cement matrices. The characteristics of these materials are difficult to transmit accurately to concrete and cement compounds, mainly due to the difficulties presented by nanomaterials in their dispersion. Therefore, the data obtained in different studies, results, very variable. However, it has been shown that, for average improvements, nanomaterials are more efficient.

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