Journal articles: 'Additifs de conduction'

1

Garcia, Michele Vargas, Dayane Domeneghini Didoné, José Ricardo Gurgel Testa, Rúbia Soares Bruno, and Marisa Frasson de Azevedo. "Visual Reinforcement Audiometry and Steady-State Auditory Evoked Potential in infants with and without conductive impairment." Revista CEFAC 20, no. 3 (May 2018): 324–32. http://dx.doi.org/10.1590/1982-0216201820312217.

Full text

Abstract:

ABSTRACT Purpose: to compare the findings of minimum levels of answers through air and bone conductions between the Visual Reinforcement Audiometry and the Steady-State Auditory Evoked Potential in infants from six to twelve months, with and without conductive disorder. Methods: sixty children aged six to twelve months were evaluated, 30 presenting conductive disorder, and 30 not presenting it. Children with malformation in the external auditory meatus with neurological alteration and / or genetic syndrome were excluded, as well as patients with sensorineural or mixed hearing loss. The infants were subjected to Visual Reinforcement Audiometry and Steady-State Auditory Evoked Potential evaluation through air and bone conduction on the same day. The results of both assessments were compared and correlated. Results: in the comparison through air conduction, for the group without conductive disorder of the medium ear, the minimum levels of response for 500 and 1000Hz were lower (better thresholds) for Steady-State Auditory Evoked Potential in both ears, and through bone conduction were very similar in all frequencies. Concerning the infants that present conductive disorder, the responses through air conduction were better in all frequencies evaluated when obtained via Steady-State Auditory Evoked Potential test. Through bone conduction, the results were very similar for both groups. Conclusion: it was possible to compare the findings to the minimum levels of response through air and bone conductions between the Visual Reinforcement Audiometry and the Steady-State Auditory Evoked Potential, being that the comparison for bone conduction in both groups presents an equivalence in the results, being very similar. In addition, for the air conduction, in the control group, there was proximity of responses of some frequencies, while the values for the Steady-State Auditory Evoked Potential test were better than the behavioral responses in the conductive disorder group.

APA, Harvard, Vancouver, ISO, and other styles

2

Gaponov, A. V. "Non-ohmic conduction in tin dioxide based ceramics with copper addition." Semiconductor Physics Quantum Electronics and Optoelectronics 14, no. 1 (February 28, 2011): 71–76. http://dx.doi.org/10.15407/spqeo14.01.071.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Zhang, Jianye, Zhiyong Huang, Chengen He, Jinlong Zhang, Peng Mei, Xiaoyan Han, Xianggang Wang, and Yingkui Yang. "Binary carbon-based additives in LiFePO4 cathode with favorable lithium storage." Nanotechnology Reviews 9, no. 1 (September 27, 2020): 934–44. http://dx.doi.org/10.1515/ntrev-2020-0071.

Full text

Abstract:

AbstractA pairwise coupling of 0D Super-P (SP), 1D carbon nanotubes (CNTs), and 2D graphene nanosheets (GNs) into binary carbon-based conductive additives was used here for the LiFePO4 cathode in lithium-ion batteries. For comparison, the LiFePO4 cathode with SP, CNT, or GN unitary conductive agent was also examined. Electrochemical test results suggest that the cathodes with binary conducting additives present greatly improved electrochemical performance than the traditional cathode system (only SP used). Especially, the LiFePO4 cathode containing 3% CNT component exhibits the highest specific capacity and the best cycling stability among all the cathodes with binary conducting additives, indicating that an appropriate amount of CNTs is critical in enhancing the conductivity and practical capacity output. However, an excess of CNTs leads to entangling with each other, hampering the uniform distribution of active materials and resulting in poor electrode performance. Furthermore, the combination of CNT and GN can effectively improve the capacity and cycling stability of the LiFePO4 cathodes due to the synergistic effect of 3D conductive networks constructed by the two.

APA, Harvard, Vancouver, ISO, and other styles

4

Sun, Jinru, Xuanjiannan Li, Xiangyu Tian, Jingliang Chen, and Xueling Yao. "Dynamic electrical characteristics of carbon fiber-reinforced polymer composite under low intensity lightning current impulse." Advanced Composites Letters 29 (January 1, 2020): 2633366X2094277. http://dx.doi.org/10.1177/2633366x20942775.

Full text

Abstract:

The distribution and conduction path of lightning current inside carbon fiber-reinforced polymer (CFRP) composites subjected to lightning strikes are determined by their dynamic conductive characteristics. An experimental platform that generates lightning current impulses with variable parameters was established to obtain the equivalent conductivities of CFRPs with different laminated structures. The experimental results indicated that the through-thickness conductivity (10−3 S/mm) was much lower than the in-plane conductivity (100 S/mm). Then, the dynamic conduction model of CFRPs was analyzed based on the anisotropic nonlinear conductivities of CFRPs under lightning currents of 50–1000 A. The CFRP laminate could be regarded as a series circuit of resistance and inductance. The dynamic conductance of the CFRP laminate first increased and then decreased during the single lightning current strike process, which was closely related to the conductive properties of the interlaminar resin. The inductive properties of the CFRP material were manifested in the test results, which showed that the voltage reached the peak value prior to the current waveform and the equivalent conductivities of the CFRPs increased as the rate of increase decreased and the duration increased. In addition, the equivalent inductance of the carbon fiber network was found to be an important part of the inductive effect of CFRP laminates. This research is helpful for understanding the complicated relationships in the lightning current conducting process and can provide experimental and theoretical support for CFRP coupled electrical–thermal simulation studies of lightning direct effects.

APA, Harvard, Vancouver, ISO, and other styles

5

Finegan, Ioana C., and Gary G. Tibbetts. "Electrical conductivity of vapor-grown carbon fiber/thermoplastic composites." Journal of Materials Research 16, no. 6 (June 2001): 1668–74. http://dx.doi.org/10.1557/jmr.2001.0231.

Full text

Abstract:

Conducting polymers are required for applications such as radio frequency interference shielding, primerless electrostatic painting, and static discharge. We have used vapor-grown carbon fiber (VGCF) as an additive to investigate conducting thermoplastics for these applications. The electrical properties of VGCF/polypropylene (PP) and VGCF/nylon composites are very attractive compared with those provided by other conventional conducting additives. Because of the low diameter of the VGCF used, the onset of conductivity (percolation threshold) can be below 3 vol%. Because of the highly conductive nature of the fibers, particularly after a graphitization step, the composites can reach resistivities as low as 0.15 Ω cm.

APA, Harvard, Vancouver, ISO, and other styles

6

Li, Ji, Thomas Wasley, Duong Ta, John Shephard, Jonathan Stringer, Patrick J. Smith, Emre Esenturk, Colm Connaughton, Russell Harris, and Robert Kay. "Micro electronic systems via multifunctional additive manufacturing." Rapid Prototyping Journal 24, no. 4 (May 14, 2018): 752–63. http://dx.doi.org/10.1108/rpj-02-2017-0033.

Full text

Abstract:

Purpose This paper aims to demonstrate the improved functionality of additive manufacturing technology provided by combining multiple processes for the fabrication of packaged electronics. Design/methodology/approach This research is focused on the improvement in resolution of conductor deposition methods through experimentation with build parameters. Material dispensing with two different low temperature curing isotropic conductive adhesive materials was characterised for their application in printing each of three different conductor designs, traces, z-axis connections and fine pitch flip chip interconnects. Once optimised, demonstrator size can be minimised within the limitations of the chosen processes and materials. Findings The proposed method of printing z-axis through layer connections was successful with pillars 2 mm in height and 550 µm in width produced. Dispensing characterisation also resulted in tracks 134 µm in width and 38 µm in height allowing surface mount assembly of 0603 components and thin-shrink small outline packaged integrated circuits. Small 149-µm flip chip interconnects deposited at a 457-µm pitch have also been used for packaging silicon bare die. Originality/value This paper presents an improved multifunctional additive manufacturing method to produce fully packaged multilayer electronic systems. It discusses the development of new 3D printed, through layer z-axis connections and the use of a single electrically conductive adhesive material to produce all conductors. This facilitates the surface mount assembly of components directly onto these conductors before stereolithography is used to fully package multiple layers of circuitry in a photopolymer.

APA, Harvard, Vancouver, ISO, and other styles

7

Lin, Jian Yang, and Bing Xun Wang. "Resistive Switching Characteristics in Nanocrystalline Silicon Films for Conductive-Bridging Resistive Random-Access Memory Applications." Applied Mechanics and Materials 284-287 (January 2013): 2565–69. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.2565.

Full text

Abstract:

In this paper, intrinsic nanocrystalline silicon thin films were deposited onto the ITO/glass substrates by PECVD and were used as the conduction material for the conductive-bridging random-access memory devices. The resistive switching characteristics of the nanocrystalline silicon thin films were investigated. Experimental results have shown that the stable bipolar resistive switching of the nc-Si films and retention time over 104s. In addition, the current conduction mechanism of the nanocrystalline silicon films was examined with XPS depth file analysis. It clearly indicates that the conduction mechanism for the resistive switching is formation metallic bridges come form metal cation migration in the nanocrystalline silicon films.

APA, Harvard, Vancouver, ISO, and other styles

8

Kamaluddin, Siti, Denni Kurniawan, Muhammad Saifullah Abu Bakar, and Zuruzi Abu Samah. "Biochar as a Conducting Filler to Enhance Electrical Conduction Monitoring for Concrete Structures." Key Engineering Materials 847 (June 2020): 149–54. http://dx.doi.org/10.4028/www.scientific.net/kem.847.149.

Full text

Abstract:

Smart and resilient concrete structures will require building materials such as cements that sense flaws. One mechanism of crack detection in structures is monitoring their electrical conduction. Two mechanisms of charge in cement is ionic movement and moisture diffusion. Carbon rich electrically-conducting char is produced by pyrolyzing rice husks and can be used to enhance electrical conduction in cement. This paper studies the evolution of electrical properties in ordinary Portland cement added with up to 15 wt% rice husk-derived biochar. Resistance of cements decreased with increasing biochar addition while moisture loss and resistance both increase as curing time increases. Cement with 15 wt% biochar experiences the largest moisture loss and the most conducting. This suggest charge transport along percolation paths of biochar particles is dominant mechanism in these materials. Electron microscopy and energy dispersive spectroscopic studies reveal formation of Ettringite phase and good wetting/bonding at the interface of biochar particles and cement.

APA, Harvard, Vancouver, ISO, and other styles

9

Cao, Zhengfeng, Yanqiu Xia, and Xiangyu Ge. "Conductive capacity and tribological properties of several carbon materials in conductive greases." Industrial Lubrication and Tribology 68, no. 5 (August 8, 2016): 577–85. http://dx.doi.org/10.1108/ilt-07-2015-0113.

Full text

Abstract:

Purpose The purpose of this paper is to synthesize a new kind of conductive grease which possesses a prominent conductive capacity and good tribological properties. Design/methodology/approach A two-step method was used to prepare complex lithium-based grease. Ketjen black (KB), acetylene black (AB) and carbon black (CB) were characterized by transmission electron microscope and used as lubricant additives to prepare conductive greases. Conductive capacity was evaluated by a conductivity meter, a surface volume resistivity meter and a circuit resistance meter. Tribological properties were investigated by a reciprocating friction and wear tester (MFT-R4000). The worn surfaces were analyzed by a scanning electron microscope, Raman spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscope. Findings The conductive grease prepared with KB has a prominent conductive capacity at room temperature, 100°C and 150°C. Further, this conductive grease also possesses better tribological properties than AB and KB greases. When the concentration of KB is 1.8 Wt.%, the coefficient of friction and wear width reduced by 11 and 14 per cent, respectively. Originality/value This work is a new application of nanometer KB as a lubricant additive in grease, which provides a direction for preparing conductive grease. The conductivity and tribology experiments have been carried out though the variation of experiment conductions.

APA, Harvard, Vancouver, ISO, and other styles

10

Polczyk, Tomasz, Wojciech Zając, Magdalena Ziąbka, and Konrad Świerczek. "Mitigation of grain boundary resistance in La2/3-xLi3xTiO3 perovskite as an electrolyte for solid-state Li-ion batteries." Journal of Materials Science 56, no. 3 (September 30, 2020): 2435–50. http://dx.doi.org/10.1007/s10853-020-05342-7.

Full text

Abstract:

Abstract In this work, we report that modification of the chemical composition of grain boundaries of La2/3-xLi3xTiO3 double perovskite, one of the most promising Li-ion conducting solid electrolytes, can be a convenient and versatile way of controlling the space charge potential, leading to a mitigated electrical resistance of the grain boundaries. Two groups of additives are investigated: lithium-enriching agents (Li3BO3, LiF) and 3d metal ions (Co2+, Cu2+), both expected to reduce the Schottky barrier. It is observed that Li-containing additives work effectively at a higher sintering temperature of 1250 °C. Regarding copper, it shows a much stronger positive impact at lower temperature, 1150 °C, while the addition of cobalt is always detrimental. Despite overall complex behavior, it is documented that the decreased space charge potential plays a more important role in the improvement of lithium conduction than the thickness of the grain boundaries. Among the proposed additives, modification of La2/3-xLi3xTiO3 by 2 mol.% Cu2+ results in the space charge potential reduction by 32 mV in relation to the reference sample, and the grain boundary specific conductivity increase by 80%, as measured at 30 °C. Introduced additive allows to obtain a similar effect on the conductivity as elevating the sintering temperature, which can facilitate manufacturing procedure. Graphic abstract

APA, Harvard, Vancouver, ISO, and other styles

11

Browning, George G., and Stuart Gatehouse. "Hearing in Chronic Suppurative Otitis Media." Annals of Otology, Rhinology & Laryngology 98, no. 4 (April 1989): 245–50. http://dx.doi.org/10.1177/000348948909800402.

Full text

Abstract:

In individuals with chronic otitis media, mixed hearing impairments are common but it is unclear whether the raised bone conduction thresholds are a reflection of the pathologic process affecting the inner ear or a combination of the high prevalence of sensorineural hearing impairments in the population along with the artificial elevation of bone conduction thresholds associated with a conductive defect. a total of 395 ears with chronic otitis media but without cholesteatoma were studied. In them, once the artificial elevation (Carhart effect) of the bone conduction thresholds, which occurs whenever there is an abnormality of the sound conduction mechanism, had been taken into account, there was no difference in the bone conduction thresholds compared with those in 920 control ears. In addition, in 100 instances, the contralateral ear was normal and there was no difference in the bone conduction thresholds between the diseased and the normal ears. Raised bone conduction thresholds in chronic otitis media are considerably likely to reflect both the Carhart effect and the high prevalence of sensorineural impairments, rather than disease damage to the inner ear.

APA, Harvard, Vancouver, ISO, and other styles

12

Wade, Phillip S., Jerry J. Halik, and Marshall Chasin. "Bone Conduction Implants: Transcutaneous vs. Percutaneous." Otolaryngology–Head and Neck Surgery 106, no. 1 (January 1992): 68–74. http://dx.doi.org/10.1177/019459989210600130.

Full text

Abstract:

Clinical experience with transcutaneous bone conduction implants has demonstrated that they are most beneficial for patients with purely conductive hearing loss in at least one ear. Percutaneous bone conduction implants, however, have been reported to provide adequate benefit for patients with mixed hearing loss with bone conduction pure-tone averages up to 45 db hl (Tjellstrom, 1989). The results of 24 Xomed Audiant osseointegrated bone conduction hearing devices (including a clinical trial on two patients using a new, larger magnet [Neodynium Iron Boron]), plus the results of eleven patients implanted and fitted with the percutaneous bone-anchored hearing aid are reported. Aided results with these devices will be presented. In addition, general comparisons of benefit obtained with the two devices will be made for patients who exhibit similar hearing losses. Finally, a direct comparison will be made on two patients who have undergone both implant procedures.

APA, Harvard, Vancouver, ISO, and other styles

13

Karakulov, A. S., N. V. Gusev, Yuriy Yu Drozdov, and N. Y. Nikonova. "The Additives Influence on Heat-Conducting Properties of Aluminium Nitride Circuit Boards." Key Engineering Materials 712 (September 2016): 226–31. http://dx.doi.org/10.4028/www.scientific.net/kem.712.226.

Full text

Abstract:

The paper presents the studies on evaluation of the influence of modified additives of Y2O3-, ZrO2- and Li2O3-type on heat-conductive properties of aluminium-nitride ceramics used as circuit boards. Sintering of the studied samples was carried out using AlN powders and the powders of the modifying additives, mixed in the ball mill based on the spark plasma sintering system “SPS”. Density and heat conductivity were measured for the obtained samples. It was ascertained that the most significant level of heat conductivity was obtained when using the additive mixture made of 7 wt. % of Li2O3 and 3wt. % of Y2O3, which reaches the level of 160 W/m·K. In addition, the results of the studies show that the addition of the modified powders leads to a significant increase of density; the additive consisting of 7wt.% of Li2O3 and 3wt.% of Y2O3 produces the greatest effect.

APA, Harvard, Vancouver, ISO, and other styles

14

Chang, Ming Kuen, Hsin Hong Hsieh, and Siou Jyuan Li. "A Study of Thermal Stability and Electromaganetic Shielding Behavior of Polyaniline-P-Toluene Sulfonic Acid/Montmorillonite Nanocomposites." Applied Mechanics and Materials 52-54 (March 2011): 180–85. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.180.

Full text

Abstract:

Intrinsically conductive polymer-Polyaniline had high conductivity and many other properties, such as environmental stability and rather simple synthesis. In addition, doping with organic acids could enhance its processing, so it had wide range of applications, such as solar cells, antistatic and electromagnetic interference shielding. In this study, the organic amine 1-Dodecylamine (DOA) modification of sodium montmorillonite (NA+-MMT), and conducting polymer / layered silicate salt nanocomposites (PANI-PTSA/DOA-MMT) had been prepared by doping aniline with organic acid (PTSA), then added organic clay. The thermal, electrical properties and EMI effects of nanocomposites had discussed by XRD, TEM, EMI, TGA analysis, conduction measure and EMI tested. The results indicated the organo-clay interlayer distance expanded from 1.29 to 1.8 nm, and DOA-MMT dispersed in the material, that formed an exfoliated nanocomposite. The thermal stability of nanocomposites depended on content of DOA-MMT, material had the better thermal stability when DOA-MMT load was 5 wt. %. The nanocomposites had the best conductivity when DOA-MMT load was 1 wt. % as well as the electromagnetic shielding effectiveness was increase with increase in conductivity. In addition, the electromagnetic shielding of nanocomposites also depended on thickness and frequency of electromagnetic wave, the electromagnetic shielding was increased with increase in thickness and frequency.

APA, Harvard, Vancouver, ISO, and other styles

15

Byraboina, Madhava Rao, Nagendra Babu Pidikiti, Sreenivas Kosaraju, Suryanarayana Murthy Kurivella, and Jagadish Mandava. "Performance assessment of synthesized conductive additive on lead acid battery formation." European Journal of Engineering Research and Science 3, no. 1 (January 22, 2018): 10. http://dx.doi.org/10.24018/ejers.2018.3.1.585.

Full text

Abstract:

The present study mainly focuses on the plate preparation and the usage of the synthesized conductive additive (Barium MetaPlumbate BaPbO3). Formation efficiency and cycle life of the plates with different additives were evaluated. The formation efficiency of the pasted positive plates of the lead-acid battery was greatly enhanced by BaPbO3 addition during the paste preparation. The effects of loading level of the additives on formation efficiency and plate performance were examined in detail by SEM, XRD, and Gravimetric, Electro Chemical Analyzer techniques.

APA, Harvard, Vancouver, ISO, and other styles

16

Suherman, Hendra, Jaafar Sahari, and Abu Bakar Sulong. "Electrical Conductivity and Micro Hardness of Synthetic and Natural Graphite Epoxy Composite." Key Engineering Materials 447-448 (September 2010): 614–18. http://dx.doi.org/10.4028/www.scientific.net/kem.447-448.614.

Full text

Abstract:

This study investigates the electrical conductivity and micro hardness of synthetic and natural graphite epoxy composite. Graphite used on this study is synthetic graphite (SG) and natural graphite (NG) with particle size 44m and 30m, respectively. Different graphite concentrations (50 ~ 80 wt.%) were added into the epoxy resin. The dispersion of graphite in epoxy resin was conducted by high speed mixer through mechanical shearing mechanism, its graphite epoxy suspension was poured into the mold and compression molding was conducted for fabrication of graphite epoxy composites. Electrical conductivity was measured by the four point probe. Microscopic analyses conducted on fracture surface use scanning electron microscopic. Results reveal that non conductive epoxy polymer becomes conductor as addition of graphite. Electrical conductivity of NG higher than SG at the same weight percentage (Wt. %) of conducting filler loading. The highest loading concentration, it exhibited values 12.6 S/cm and 7 S/cm at (80 Wt. %). Hardness property of epoxy composites of both type of graphite increase continuously and reached peak at 60 wt% for NG and 70 wt % for SG, while more addition decreased it.

APA, Harvard, Vancouver, ISO, and other styles

17

Karhuketo, Tapio S., Heikki J. Puhakka, and Pekka J. Laippala. "Tympanoscopy to increase the accuracy of diagnosis in conductive hearing loss." Journal of Laryngology & Otology 112, no. 2 (February 1998): 154–57. http://dx.doi.org/10.1017/s0022215100140174.

Full text

Abstract:

AbstractThe diagnosis of conductive hearing loss is usually based on audiological methods and radiology. The aim of our study was to show that there is a useful additive method to clarify the findings of diseases with conductive hearing loss.Patients (151 ears) with conductive hearing loss were examined using several methods: otomicroscopy, air- and bone-conduction threshold, pure tone average, speech threshold, speech discrimination, tympanometry and stapedial reflex and tympanoscopy.The management of the patients changed in 17 per cent of cases due to tympanoscopy. In a group with normal tympanic membrane the movement of the stapes during endoscopy was compared to stapedial reflex. Stiff stapes were found more often than an abnormal stapedial reflex.Middle ear endoscopy can increase the accuracy of diagnosis of conductive hearing loss thus enhancing decision making in the case of the patient.

APA, Harvard, Vancouver, ISO, and other styles

18

Barker, Alison P. "Conduction calorimetric studies of cements containing 5% additions." Cement and Concrete Research 20, no. 2 (March 1990): 219–26. http://dx.doi.org/10.1016/0008-8846(90)90074-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Lovric, Dino, Slavko Vujevic, and Ivan Krolo. "Computation of per-unit-length internal impedance of a multilayer cylindrical conductor with possible dielectric layers." Facta universitatis - series: Electronics and Energetics 33, no. 4 (2020): 605–16. http://dx.doi.org/10.2298/fuee2004605l.

Full text

Abstract:

In this manuscript, a novel method for computation of per-unit-length internal impedance of a cylindrical multilayer conductor with conductive and dielectric layers is presented in detail. In addition to this, formulas for computation of electric and magnetic field distribution throughout the entire multilayer conductor (including dielectric layers) have been derived. The presented formulas for electric and magnetic field in conductive layers have been directly derived from Maxwell equations using modified Bessel functions. However, electric and magnetic field in dielectric layers has been computed indirectly from the electric and magnetic fields in contiguous conductive layers which reduces the total number of unknowns in the system of equations. Displacement currents have been disregarded in both conductive and dielectric layers. This is justifiable if the conductive layers are good conductors. The validity of introducing these approximations is tested in the paper versus a model that takes into account displacement currents in all types of layers.

APA, Harvard, Vancouver, ISO, and other styles

20

Onoda, Mitsuyoshi. "N-Type Conductive Polymer Having a Concept of Self-Dope: —Poly(P-methylpyridinium vinylene)—." Journal of Nanoscience and Nanotechnology 16, no. 4 (April 1, 2016): 3213–18. http://dx.doi.org/10.1166/jnn.2016.12284.

Full text

Abstract:

Novel self-doped N-type conducting polymer, poly(P-methylpyridinium vinylene), PMePyV were synthesized by using the quaternization of poly(P-pyridyl vinylene), PPyV and several regiochemical consequences in this polymer were proposed. The electrical, optical, and electrochemical properties of self-doped N-type conductive polymer were observed. In addition, a possibility of a variety of functional applications of self-doped N-type conductive polymer was indicated.

APA, Harvard, Vancouver, ISO, and other styles

21

Zhang, Hao, Xiaowen Zhang, Zhou Fang, Yao Huang, Hong Xu, Ying Liu, Daming Wu, Jian Zhuang, and Jingyao Sun. "Recent Advances in Preparation, Mechanisms, and Applications of Thermally Conductive Polymer Composites: A Review." Journal of Composites Science 4, no. 4 (November 29, 2020): 180. http://dx.doi.org/10.3390/jcs4040180.

Full text

Abstract:

At present, the rapid accumulation of heat and the heat dissipation of electronic equipment and related components are important reasons that restrict the miniaturization, high integration, and high power of electronic equipment. It seriously affects the performance and life of electronic devices. Hence, improving the thermal conductivity of polymer composites (TCPCs) is the key to solving this problem. Compared with manufacturing intrinsic thermally conductive polymer composites, the method of filling the polymer matrix with thermally conductive fillers can better-enhance the thermal conductivity (λ) of the composites. This review starts from the thermal conduction mechanism and describes the factors affecting the λ of polymer composites, including filler type, filler morphology and distribution, and the functional surface treatment of fillers. Next, we introduce the preparation methods of filled thermally conductive polymer composites with different filler types. In addition, some commonly used thermal-conductivity theoretical models have been introduced to better-analyze the thermophysical properties of polymer composites. We discuss the simulation of λ and the thermal conduction process of polymer composites based on molecular dynamics and finite element analysis methods. Meanwhile, we briefly introduce the application of polymer composites in thermal management. Finally, we outline the challenges and prospects of TCPCs.

APA, Harvard, Vancouver, ISO, and other styles

22

Wu, Shao Peng, Bo Li, Hong Wang, and Jian Qiu. "Numerical Simulation of Temperature Distribution in Conductive Asphalt Solar Collector due to Pavement Material Parameters." Materials Science Forum 575-578 (April 2008): 1314–19. http://dx.doi.org/10.4028/www.scientific.net/msf.575-578.1314.

Full text

Abstract:

Asphalt pavement serving as solar collector has been developed for the heating and cooling of adjacent buildings as well as to keep the pavement ice-free directly. Material parameters such as thermal conductivity and heat capacity are some of the critical parameters related to the efficiency of the asphalt collector. Graphite powders were utilized as thermal conductive fillers to make asphalt collector conductive so as to improve the efficiency of the asphalt collector. The material parameters change with the addition of graphite consequently. In order to access the solar energy absorbability of conductive asphalt collector, it is necessary to predict the temperature distribution within the asphalt layers. A transient, two-dimensional finite element model is developed to predict temperature distributions in conductive asphalt solar collector due to material parameters. The ability of accurately predict asphalt pavement temperature at different depths will greatly help pavement engineers in determining the solar energy potential of conductive asphalt collector. The results from the prediction model show that the surface temperature of pavement decreases slightly with addition of graphite. The differential maximum asphalt temperature variation at a depth of 10cm is significantly more than that at the surface. Higher temperature and lower temperature gradient can also be observed at the depth of 10cm because the heat conduction is accelerated by the addition of graphite.

APA, Harvard, Vancouver, ISO, and other styles

23

Park, Hee Jung, and Jong Wook Roh. "Protonic Conduction of Nanostructured Y-Doped BaZrO3." Journal of Nanomaterials 2016 (2016): 1–6. http://dx.doi.org/10.1155/2016/8757305.

Full text

Abstract:

Nanostructured ionic conductors have recently attracted our attention due to the expectation that they may lead to new functionalities absent in microcrystalline conductors. In this study, nanostructured barium zirconate with perovskite crystal structure was prepared and its grain and grain boundary protonic conduction was investigated using ac impedance measurements as a function of temperature (RT ~ 400°C) and water partial pressure. The grain was highly conductive of protons, which is governed by the concentration of protonic defects at all temperatures. On the other hand, the grain boundary was not the preferred route for protonic conduction due to high resistance. However, enhanced protonic transport was observed at certain temperatures (<100°C). The protonic resistivity below that temperature decreased with decreasing temperature, showing positive activation energy in relation to temperature. The conduction route for the enhanced transport was the serial grain boundary. In addition, the route was compared with that of nanostructured zirconia with fluorite crystal-structure.

APA, Harvard, Vancouver, ISO, and other styles

24

Barši Palmić, Tibor, Janko Slavič, and Miha Boltežar. "Process Parameters for FFF 3D-Printed Conductors for Applications in Sensors." Sensors 20, no. 16 (August 13, 2020): 4542. http://dx.doi.org/10.3390/s20164542.

Full text

Abstract:

With recent developments in additive manufacturing (AM), new possibilities for fabricating smart structures have emerged. Recently, single-process fused-filament fabrication (FFF) sensors for dynamic mechanical quantities have been presented. Sensors measuring dynamic mechanical quantities, like strain, force, and acceleration, typically require conductive filaments with a relatively high electrical resistivity. For fully embedded sensors in single-process FFF dynamic structures, the connecting electrical wires also need to be printed. In contrast to the sensors, the connecting electrical wires have to have a relatively low resistivity, which is limited by the availability of highly conductive FFF materials and FFF process conditions. This study looks at the Electrifi filament for applications in printed electrical conductors. The effect of the printing-process parameters on the electrical performance is thoroughly investigated (six parameters, >40 parameter values, >200 conductive samples) to find the highest conductivity of the printed conductors. In addition, conductor embedding and post-printing heating of the conductive material are researched. The experimental results helped us to understand the mechanisms of the conductive network’s formation and its degradation. With the insight gained, the optimal printing strategy resulted in a resistivity that was approx. 40% lower than the nominal value of the filament. With a new insight into the electrical behavior of the conductive material, process optimizations and new design strategies can be implemented for the single-process FFF of functional smart structures.

APA, Harvard, Vancouver, ISO, and other styles

25

Gao, Xiaolong, Yao Huang, Xiaoxiang He, Xiaojing Fan, Ying Liu, Hong Xu, Daming Wu, and Chaoying Wan. "Mechanically Enhanced Electrical Conductivity of Polydimethylsiloxane-Based Composites by a Hot Embossing Process." Polymers 11, no. 1 (January 2, 2019): 56. http://dx.doi.org/10.3390/polym11010056.

Full text

Abstract:

Electrically conductive polymer composites are in high demand for modern technologies, however, the intrinsic brittleness of conducting conjugated polymers and the moderate electrical conductivity of engineering polymer/carbon composites have highly constrained their applications. In this work, super high electrical conductive polymer composites were produced by a novel hot embossing design. The polydimethylsiloxane (PDMS) composites containing short carbon fiber (SCF) exhibited an electrical percolation threshold at 0.45 wt % and reached a saturated electrical conductivity of 49 S/m at 8 wt % of SCF. When reducing the sample thickness from 1.0 to 0.1 mm by the hot embossing process, a compression-induced percolation threshold occurred at 0.3 wt %, while the electrical conductivity was further enhanced to 378 S/m at 8 wt % SCF. Furthermore, the addition of a second nanofiller of 1 wt %, such as carbon nanotube or conducting carbon black, further increased the electrical conductivity of the PDMS/SCF (8 wt %) composites to 909 S/m and 657 S/m, respectively. The synergy of the densified conducting filler network by the mechanical compression and the hierarchical micro-/nano-scale filler approach has realized super high electrically conductive, yet mechanically flexible, polymer composites for modern flexible electronics applications.

APA, Harvard, Vancouver, ISO, and other styles

26

Wang, Tongjiang, Leon Ofman, Xudong Sun, Elena Provornikova, and Joseph M. Davila. "Evidence of thermal conduction suppression in hot coronal loops: supplementary results." Proceedings of the International Astronomical Union 11, S320 (August 2015): 202–8. http://dx.doi.org/10.1017/s1743921316000326.

Full text

Abstract:

AbstractSlow magnetoacoustic waves were first detected in hot (>6 MK) flare loops by the SOHO/SUMER spectrometer as Doppler shift oscillations in Fe xix and Fe xxi lines. Recently, such longitudinal waves have been found by SDO/AIA in the 94 and 131 Å channels. Wang et al. (2015) reported the first AIA event revealing signatures in agreement with a fundamental standing slow-mode wave, and found quantitative evidence for thermal conduction suppression from the temperature and density perturbations in the hot loop plasma of ≳ 9 MK. The present study extends the work of Wang et al. (2015) by using an alternative approach. We determine the polytropic index directly based on the polytropic assumption instead of invoking the linear approximation. The same results are obtained as in the linear approximation, indicating that the nonlinearity effect is negligible. We find that the flare loop cools slower (by a factor of 2–4) than expected from the classical Spitzer conductive cooling, approximately consistent with the result of conduction suppression obtained from the wave analysis. The modified Spitzer cooling timescales based on the nonlocal conduction approximation are consistent with the observed, suggesting that nonlocal conduction may account for the observed conduction suppression in this event. In addition, the conduction suppression mechanism predicts that larger flares may tend to be hotter than expected by the EM-T relation derived by Shibata & Yokoyama (2002).

APA, Harvard, Vancouver, ISO, and other styles

27

Shen, Chi-Yen, Long Wu, and Ying-Chung Chen. "Effect of Additions on Conduction Properties of ZnO Varistors." Japanese Journal of Applied Physics 32, Part 1, No. 5A (May 15, 1993): 2043–46. http://dx.doi.org/10.1143/jjap.32.2043.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Köse, Hidayet, and Suat Çetiner. "The Effect of Dopant Type on The Morphology and Electrical Properties of Hollow Polyester Fabric." Academic Perspective Procedia 2, no. 3 (November 22, 2019): 577–82. http://dx.doi.org/10.33793/acperpro.02.03.55.

Full text

Abstract:

Intrinsically conducting polymers (ICPs) have been intensively the subject of research since these polymers have superlative electrical and thermophysical properties. Due to the low hydrogen content and aromatic structure, they show perfect chemical, thermal, and oxidative stability and are practically insoluble in all common solvents. Also these polymers are latently electrical conducting materials, especially when doped. Polypyrole (PPy) is a very promising conducting polymer. It can be in easy way processes and has many interesting electrical properties. Also ıt is chemically and thermally stable. Like many other fully aromatic polymers, PPy is an electrical insulator, however, when oxidized it becomes an electrical conductor.The conductivity of PPy strongly consists in the preparation technique, and on the polymer additives and can be increased by about two orders of magnitude. In this study, electrically conductive hollow fabrics were prepared via ın situ chemical polymerization method and scanning electron microscopy (SEM) and electrical properties of conductive hollow fabrics were invesigated.

APA, Harvard, Vancouver, ISO, and other styles

29

Qin, Jun Jie, Wu Yao, Jun Qing Zuo, and Hai Yong Cao. "Assessment on the Electrical Conductivity of Additive Fillers into Carbon Fiber-Cement Based Composites." Key Engineering Materials 492 (September 2011): 185–88. http://dx.doi.org/10.4028/www.scientific.net/kem.492.185.

Full text

Abstract:

This paper gives an assessment on the electrical conductivity of different additive fillers (graphite, multi-walled carbon nanotubes) into carbon fiber-cement based composites (CFRC). Results show that cement matrix containing 0.4% carbon fiber (CF) and 0.5% multi-walled carbon nanotubes (MWCNTs) exhibits an excellent electrical conductivity of 33.65Ω·cm. When the content of CF is below the percolation threshold (0.4% CF), adding graphite is beneficial to the electrical conduction of CFRC, which has a tremendous drift from 3991.44Ω·cm to 524.33Ω·cm as the content of graphite varies from 0% to 30%. However, when the content of CF is above the percolation threshold, adding graphite makes no advantages in the electrical conductivity of CFRC because of leading to a porosity rising. MWCNTs are useful conductive constituents for CFRC and can increase electrical conductivity by two orders of magnitude. However, excessive adding MWCNTs into CFRC will have a rapid increase of electrical resistivity on the contrary.

APA, Harvard, Vancouver, ISO, and other styles

30

Choi, Yu-Song, Hae-Won Cheong, Ki-Youl Kim, and Sung-Baek Cho. "Effect of Conductive Additives on FeS2Cathode." Journal of the Korea Institute of Military Science and Technology 15, no. 2 (April 5, 2012): 224–30. http://dx.doi.org/10.9766/kimst.2012.15.2.224.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Yuen, W. W., and E. E. Takara. "Analysis of Combined Conductive-Radiative Heat Transfer in a Two-Dimensional Rectangular Enclosure With a Gray Medium." Journal of Heat Transfer 110, no. 2 (May 1, 1988): 468–74. http://dx.doi.org/10.1115/1.3250509.

Full text

Abstract:

Combined conductive–radiative heat transfer in a two-dimensional enclosure is considered. The numerical procedure is based on a combination of two previous techniques that have been demonstrated to be successful for a two-dimensional pure radiation problem and a one-dimensional combined conductive–radiative heat transfer problem, respectively. Both temperature profile and heat transfer distributions are generated efficiently and accurately. Numerical data are presented to serve as benchmark solutions for two-dimensional combined conductive–radiative heat transfer. The accuracy of two commonly used approximation procedures for multidimensional combined conductive–radiative heat transfer is assessed. The additive solution, which is effective in generating approximation to one-dimensional combined conductive–radiative heat transfer, appears to be an acceptable empirical approach in estimating heat transfer in the present two-dimensional problem. The diffusion approximation, on the other hand, is shown to be generally inaccurate. For all optical thicknesses and conduction-radiation parameters considered (including the optically thick limit), the diffusion approximation is shown to yield significant errors in both the temperature and heat flux predictions.

APA, Harvard, Vancouver, ISO, and other styles

32

Qin, Yue Ping, Hong Bo Liu, Chuan Qin, and Guo Hui Su. "Comparative Study of FVM and FEM Using Rectangular Element in Heat Conduction Problems for Conductive Materials." Advanced Materials Research 321 (August 2011): 131–35. http://dx.doi.org/10.4028/www.scientific.net/amr.321.131.

Full text

Abstract:

This paper established the mathematic model of plane transient temperature field using the Finite Volume Method according to the energy conservation rule, it clearly interprets the actual physical meaning of fundamental formula in the calculus of variations. The computational domains were subdivided by rectangular elements and the contributing formula was obtained from the elements to respective dots. Comparing the results with FEM results showed that they have same coefficient except the coefficient of time change. This paper analyzed the reason of the different results between FEM and FVM. In addition, the actual problem of two-dimensional temperature field of thermal calculations is resolved by the new arithmetic of FVM and the FEM. Comparing FVM results with the theoretical solution and FEM result shows that the FVM is more approximate to the theoretical solution than the FEM. The new arithmetic of FVM not only can simplify the process of establish equation and make the meaning of formula understandable but also can ensure the calculation accuracy. What’s more, it can extend widely the applied range of the FVM on the problem of temperature field, and has great application value on solving complicated technological problems.

APA, Harvard, Vancouver, ISO, and other styles

33

Ganiev, I. N., A. P. Abdulakov, J. H. Jayloev, U. Sh Yakubov, A. G. Safarov, and V. D. Abulkhaev. "Influence of bismuth additives on the thermophysical and thermodynamic properties of aluminum conductive alloy E-AlMgSi (Aldrey)." Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering 23, no. 1 (June 10, 2020): 86–93. http://dx.doi.org/10.17073/1609-3577-2020-1-86-93.

Full text

Abstract:

The economic feasibility of using aluminum as a conductive material is explained by the favorable ratio of its cost to the cost of copper. It is also important that the cost of aluminum for many years remains virtually unchanged.When using conductive aluminum alloys for the manufacture of thin wire, winding wire, etc. Certain difficulties may arise in connection with their insufficient strength and a small number of kinks before fracture. In recent years, aluminum alloys have been developed, which even in a soft state have strength characteristics that allow them to be used as a conductive material.One of the promising areas for the use of aluminum is the electrical industry. Conducting aluminum alloys of the E-AlMgSi type (Aldrey) are representatives of this group of alloys. The paper presents the results of a study of the temperature dependence of heat capacity, heat transfer coefficient, and thermodynamic functions of an aluminum alloy E-AlMgSi (Aldrey) with bismuth. Research conducted in the "cooling" mode.It was shown that the temperature capacity and the thermodynamic functions of the alloy E-AlMgSi (Aldrey) with bismuth increase with temperature, and the Gibbs energy decreases. Additives of bismuth up to 1 wt.% Reduce heat capacity, heat transfer coefficient, enthalpy and entropy of the initial alloy and increase the value of Gibbs energy.

APA, Harvard, Vancouver, ISO, and other styles

34

Chowdhury, C. R., S. Y. Tsao, J. H. C. Ho, G. K. H. Au, A. Wright, and Y. Tung. "Prospective Study of the Effects of Ventilation Tubes on Hearing after Radiotherapy for Carcinoma of Nasopharynx." Annals of Otology, Rhinology & Laryngology 97, no. 2 (March 1988): 142–45. http://dx.doi.org/10.1177/000348948809700210.

Full text

Abstract:

In patients with nasopharyngeal carcinoma, deafness sometimes occurs following radiotherapy. It is usually conductive, but may be sensorineural. Tinnitus is present frequently and usually is distressing. The role of ventilation tubes (grommets) in relieving these problems was assessed in a prospective randomized controlled trial of 115 patients. In the group with grommets, there was an improvement in hearing, with a reduction of the averaged air-bone gap (p< .01). This was not found in the control group without ventilation tubes, who developed a larger conductive loss (p< .01) and, in addition, a slight deterioration of the averaged bone conduction threshold (p< .01). Surprisingly, the group with grommets did not develop this sensorineural loss (p> .01). In addition, tinnitus was improved significantly by the insertion of ventilation tubes (p< .01). Neither necrosis nor stenosis of the external auditory meatus was found in either group.

APA, Harvard, Vancouver, ISO, and other styles

35

Ganiev, Izatullo N., Aslam P. Abulakov, Jamshed H. Jayloev, Umarali Sh Yakubov, Amirsho G. Safarov, and Vladimir Dz Abulkhaev. "Effect of bismuth additions on the thermophysical and thermodynamical properties of E-AlMgSi (Aldrey) aluminum semiconductor alloy." Modern Electronic Materials 6, no. 3 (September 30, 2020): 107–12. http://dx.doi.org/10.3897/j.moem.6.3.63734.

Full text

Abstract:

The economic feasibility of using aluminum as a conductive material is explained by the favorable ratio of its cost to the cost of copper. In addition, one should take into account that the cost of aluminum has remained virtually unchanged for many years. When using conductive aluminum alloys for the manufacture of thin wire, winding wire, etc., certain difficulties may arise in connection with their insufficient strength and a small number of kinks before fracture. Aluminum alloys have been developed in recent years which even in a soft state have strength characteristics that allow them to be used as a conductive material. The electrochemical industry is one of the promising application fields of aluminum. E-AlMgSi (Aldrey) conductor aluminum alloys represent this group of alloys. This work presents data on the temperature dependence of heat capacity, heat conductivity and thermodynamic functions of the E-AlMgSi (Aldrey) aluminum alloy doped with bismuth. The studies have been carried out in "cooling" mode. It has been shown that the heat capacity and thermodynamic functions of the E-AlMgSi (Aldrey) aluminum alloy doped with bismuth increase with temperature and the Gibbs energy decreases. Bismuth additions of up to 1 wt.% reduce the heat capacity, heat conductivity, enthalpy and entropy of the initial alloy and increase the Gibbs energy.

APA, Harvard, Vancouver, ISO, and other styles

36

Higgins, Thomas M., Sang-Hoon Park, Paul J. King, Chuanfang (John) Zhang, Niall McEvoy, Nina C. Berner, Dermot Daly, et al. "A Commercial Conducting Polymer as Both Binder and Conductive Additive for Silicon Nanoparticle-Based Lithium-Ion Battery Negative Electrodes." ACS Nano 10, no. 3 (March 8, 2016): 3702–13. http://dx.doi.org/10.1021/acsnano.6b00218.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Shen, Zhenzhen, and Aleksey Reiderman. "Additive Manufacturing for Multi-chip Modules." International Symposium on Microelectronics 2018, no. 1 (October 1, 2018): 000760–66. http://dx.doi.org/10.4071/2380-4505-2018.1.000760.

Full text

Abstract:

Abstract The implementation of microelectronics, also known as multi-chip modules (MCM), is extensive in automotive, downhole and aerospace applications. MCMs have already demonstrated high-temperature performance, step improvement in reliability, and the potential to reduce product cost through miniaturization and integration of more functions. However, there are barriers preventing wider adoption of MCM technology in downhole applications. High non-recurring expenditures (NRE) charges increase development costs. Long substrate lead times prolong the time to market. Lengthy design iterations make it difficult to apply lean startup methodology to accelerate innovation. The main factor that leads to high NRE and long lead times is the complexity of substrate manufacturing processes. Together with assembly, MCM manufacturing comprises at least 11 steps, 6 different materials, 10 or more different machines, and requires a minimum of 6 supporting employees. A new concept proposes a simplified process to reduce labor and expenses. With best implementation, this process would require only a single machine capable of cycling through 3-step process of dispensing, placement and cure. Despite the dramatically simplified process, the constructional complexity of circuits can still be very high, such as a 3D multilayer MCM. In this paper, this concept was evaluated, micro-dispensing equipment was used to create basic circuitry blocks. Different materials to create conductive traces, isolation layers and wire bond replacement were evaluated. High-temperature aging tests were conducted to monitor the electrical and mechanical performance under thermal stress. The feasibility of dispensing fine features using dispensing and jetting methods are presented in the study. Conductors are a critical part in microelectronic assemblies because they create interconnects and thermal dissipation paths for microelectronics. Three different conductor materials were tested for their dispensability, resistance, continuity at temperature, and coefficients of thermal expansion (CTE) compatibility with different materials under thermal cycling. For dielectric materials, the requirements were to create various assembly constructs. The characterization included dispensability, electrical insulation, breakdown voltage, high-temperature performance, and the effects of CTE. Different approaches with different materials were tested for feasibility for wire bonding replacement. The application needs fine feature size with medium resistance lines. Consequently, the criteria for the material selection are fine particle size and medium sheet resistance. For high-power devices where heavy-gauge wires were used, jet dispensing is applicable. For other application with regular wire diameters, direct write is used. The over-all tests demonstrated the feasibility of using dispensed materials to replace wire bonds, which brings better reliability for shock and vibration, as compared to traditional wire bonds. The reliability of this approach requires a set of optimally matched conductive and dielectric materials. Three conductive materials (A, B and C) and three dielectric materials (D, E and F) were evaluated in this study. Tested conductive epoxy A can be used for attachment of SMT components with non-tin terminals, short traces, and wire bonding replacement for 25-μm wires, but it is not ideal for fine lines(<65um). Tested conductive epoxy B can be used for fine traces (58μm), and wire bonding replacement for 25-μm wires. The resistance of that material is not ideal. Nano-silver paste can be used for long traces, heavy-gauge wire bonding replacement, pads/polygons, the sheet resistance is equivalent to 0.5Oz Cu. For dielectrics, epoxy C can be used for crossovers, dielectric layers, and components staking. Epoxy D can be used for die edge insulation, but it is not ideal. Epoxy E can be used for crossovers and components staking. Epoxy F can be used for encapsulation and components staking. The wire bonding replacement concept structure is established with the dielectric forming the insulation around die edge, then the conductive wires dispensed on top of it. Feasibility was confirmed, a proof-of-concept was built, and some level of thermal stress was tested on the samples. Particle size and viscosity are critical to achieve fine features for micro-dispensing conductors and dielectrics. Periodic evaluations must be conducted to follow up on industry's progress with materials.

APA, Harvard, Vancouver, ISO, and other styles

38

Prasad, A., and S. P. Singh. "Conduction-Controlled Phase-Change Energy Storage With Radiative Heat Addition." Journal of Energy Resources Technology 116, no. 3 (September 1, 1994): 218–23. http://dx.doi.org/10.1115/1.2906446.

Full text

Abstract:

Thermal energy storage in a phase-change material due to latent heat of fusion caused by conduction-controlled melting during radiative heat injection is considered. It is solved employing variational, integral, and quasi-steady methods. They yield closed-form solutions which are functions of the Stefan number, St, and the surrounding temperature. The results for the design parameters for the storage system obtained from these methods exhibit insignificant variation and are unaffected by the surrounding temperature, θa, for St<0.1. The second law efficiency for this storage is devised. It is insensitive to changes in St and the heat absorption depth, ηm, for θa≤ 1.2.

APA, Harvard, Vancouver, ISO, and other styles

39

Stump, B., and A. Plotkowski. "An adaptive integration scheme for heat conduction in additive manufacturing." Applied Mathematical Modelling 75 (November 2019): 787–805. http://dx.doi.org/10.1016/j.apm.2019.07.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

AlFannakh, Huda, S. S. Arafat, and S. S. Ibrahim. "Synthesis, electrical properties, and kinetic thermal analysis of polyaniline/ polyvinyl alcohol - magnetite nanocomposites film." Science and Engineering of Composite Materials 26, no. 1 (January 28, 2019): 347–59. http://dx.doi.org/10.1515/secm-2019-0020.

Full text

Abstract:

AbstractPolyaniline-poly vinyl alcohol (PANI-PVA) conducting blends containing 15 wt% aniline were synthesized by in situ polymerization of aniline. Three-phase polymer blended nanocomposites with different contents of magnetite (5, 10 and 15 wt.%) were also synthesized. We measured the current-voltage (I-V) curves for the conducting blend and its magnetite nanocomposite. We also measured their thermal stability, and performed kinetic analysis through thermogravimetric analysis. We observed that the three phase nanocomposites showed enhanced electrical conductivity compared with that of the conductive blend, and no electrical hysteresis. The PVA/PANi blend was more stable above 350∘C and the addition of Fe3O4 enhanced the thermal stability of the conductive blend. The apparent activation energy of the three phase nanocomposites was greater than those of both the pure PVA and PVA/PANi samples. These results suggest that such three phase nanocomposites could be used in a range of applications.

APA, Harvard, Vancouver, ISO, and other styles

41

Lee, Chin Jung, and I. Shou Tsai. "Effect of Different Dielectric Constant Solvents Addition on PEDOT-PSS Conductive Polymer and its Application." Materials Science Forum 687 (June 2011): 625–33. http://dx.doi.org/10.4028/www.scientific.net/msf.687.625.

Full text

Abstract:

This paper investigates the physical properties of conductive paste which is used for print engineering. The conductivity of poly (3,4-ethylenedioxythiophene) (PEDOT) doped with poly(4-styrenesulfonate) (PSS) containing various organic solvents was measured. The different dielectric constant solvents are isopropanol, N-methyl-2-pyrrolidone, N,N-dimethyl acetamide, dimethyl sulfoxide with different concentration. After drying, they were prepared many kinds of films. It was found that an addition of organic solvent lowered the resistance by two or three orders of magnitude when the concentration is 25wt% , among them the larger dielectric constant solvent has the best surface conductivity, the magnitude is about 7.03×10－1S/cm, and then we blend every two solvents by 25wt% concentration, prepared six blend films. Among them has the best effect, the magnitude is about 1.94×10-1S/cm. All kind of PEDOT/PSS films have been studied using four point probe conductive meter, X-ray diffractometry (XRD), fourier transform infrared (FTIR), thermogravimetric analysis(TGA) in order to discuss the surface conductivity, the crystallinity, the chemical structure and the thermal properties of the PEDOT/PSS film. Conducting PEDOT/PSS-IPA/DMSO solution mix with polymethyl-methacrylate (PMMA) resin to coat hydrophobic fabrics, which can be used for the dissipation of electrostatic charge.

APA, Harvard, Vancouver, ISO, and other styles

42

Choi, C. Y., S. J. Kim, and A. Ortega. "Effects of Substrate Conductivity on Convective Cooling of Electronic Components." Journal of Electronic Packaging 116, no. 3 (September 1, 1994): 198–205. http://dx.doi.org/10.1115/1.2905686.

Full text

Abstract:

The coupled conduction and forced convection transport from substrate-mounted modules in a channel is numerically investigated to identify the effects of the substrate conductivity. The results presented apply to air and two-dimensional laminar flow conditions. It was found that recirculating cells as well as streamwise conduction through the substrate play an important role in predicting convective heat transfer from the printed circuit board (PCB) and modules and in determining the temperature distributions in the PCB, modules, and fluid. The dimensionless temperature and the local Nusselt number along the interface between the fluid and the module or PCB are rather complicated, and therefore, predetermined simple boundary conditions along the solid surface may be inappropriate in many conjugate heat transfer problems. In general, the results show that the maximum temperature within heat sources can be greatly reduced by increasing the conductivity of the PCB. The effectiveness of the use of highly conductive materials for PCB, however, depends on the distance between the heat generating modules on the PCB. In addition, finite thermal resistance between the module and the PCB would serve to diminish the PCB conduction effects, thereby reducing the effectiveness of the enhancement afforded by increased conductivity.

APA, Harvard, Vancouver, ISO, and other styles

43

Singh, Atma Ram, Debapriya Choudhury, Gora Ghosh, and Sunil K. Srivastava. "Additives for Conducting Polymer Membrane from Coal." Open Fuels & Energy Science Journal 3, no. 1 (April 2, 2010): 8–16. http://dx.doi.org/10.2174/1876973x01003010008.

Full text

Abstract:

For the first time, an additive for conducting polymer membrane has been prepared from an Indian coal. Samla coal from Raniganj coalfield having 80% carbon on dmmf basis was first demineralised chemically and then degraded by oxidizing it with oxidizing agent followed by solubilization of oxy coal thus produced in polar organic solvent. The soluble part of the coal was dried and the solid residual part along with a neutral base material polyvinyl alcohol was used for making additive for conducting polymer membrane in the form of a coloured thin film. The quality of the film/membrane made has been extremely good and the conductance is in the range of 10-3 to 10-4 units (Scm-1). Due to non explanation of enhancement in carboxylic acid functional groups, on oxidation, from 1.2% to 18.3% by the Mazumdar's proposed model coal structure, an anomaly with respect to 9-10 position of phenanthrene is observed and reported here and a correction to this has been proposed which explains the experimental results.

APA, Harvard, Vancouver, ISO, and other styles

44

Markarian, Jennifer. "New developments in antistatic and conductive additives." Plastics, Additives and Compounding 10, no. 5 (September 2008): 22–25. http://dx.doi.org/10.1016/s1464-391x(08)70172-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Beniak, Juraj, Peter Krizan, and Milos Matus. "CONDUCTIVE MATERIAL PROPERTIES FOR FDM ADDITIVE MANUFACTURING." MM Science Journal 2020, no. 1 (March 4, 2020): 3846–51. http://dx.doi.org/10.17973/mmsj.2020_03_2019135.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Nayak, Rajkishore, Ilias Louis Kyratzis, Yen Bach Truong, Rajiv Padhye, and Lyndon Arnold. "Melt-electrospinning of polypropylene with conductive additives." Journal of Materials Science 47, no. 17 (May 23, 2012): 6387–96. http://dx.doi.org/10.1007/s10853-012-6563-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Huang, Alicia, Kui Yao, and John Wang. "Conducting perovskite LaNi0.6Co0.4O3 ceramics with glass additions." Journal of Electroceramics 16, no. 4 (July 2006): 313–19. http://dx.doi.org/10.1007/s10832-006-9871-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Huang, Yi-Hsiang, and Suresh K. Aggarwal. "Effect of Wall Conduction on Natural Convection in an Enclosure With a Centered Heat Source." Journal of Electronic Packaging 117, no. 4 (December 1, 1995): 301–6. http://dx.doi.org/10.1115/1.2792109.

Full text

Abstract:

This study presents a numerical investigation of the effects of wall conduction on laminar natural convection heat transfer in a two-dimensional rectangular enclosure. The heat transfer is driven by a constant-temperature heat source in the center of the enclosure. The time dependent governing equations in the primitive form are solved numerically by the use of a finite-volume method. The numerical algorithm is first validated by comparing our predictions with those of Kim and Viskanta for a square cavity surrounded by four conducting walls. A parametric study is then conducted to examine the effects of wall conduction on the natural convection heat transfer. The parameters include the Rayleigh number, wall thickness, wall thermal conductivity ratio and diffusivity ratio. In addition, the effects of varying thermal boundary conditions on the outside walls are reported. Results indicate that the qualitative features of natural convection heat transfer in the laminar range are not significantly altered by the inclusion of wall conduction. However, the quantitative results may be significantly modified by the wall conductance. In general, the wall conduction reduces the rate of heat dissipation from the enclosure. The average Nusselt number decreases as the wall thickness ratio is increased and/or the wall thermal conductivity is reduced. Results also indicate that it may be possible to define an effective Rayleigh number that includes the effects of wall thickness and conductivity.

APA, Harvard, Vancouver, ISO, and other styles

49

Sirivisoot, Sirinrath, Rajesh Pareta, and Benjamin S. Harrison. "Protocol and cell responses in three-dimensional conductive collagen gel scaffolds with conductive polymer nanofibres for tissue regeneration." Interface Focus 4, no. 1 (February 6, 2014): 20130050. http://dx.doi.org/10.1098/rsfs.2013.0050.

Full text

Abstract:

It has been established that nerves and skeletal muscles respond and communicate via electrical signals. In regenerative medicine, there is current emphasis on using conductive nanomaterials to enhance electrical conduction through tissue-engineered scaffolds to increase cell differentiation and tissue regeneration. We investigated the role of chemically synthesized polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT) conductive polymer nanofibres for conductive gels. To mimic a naturally derived extracellular matrix for cell growth, type I collagen gels were reconstituted with conductive polymer nanofibres and cells. Cell viability and proliferation of PC-12 cells and human skeletal muscle cells on these three-dimensional conductive collagen gels were evaluated in vitro . PANI and PEDOT nanofibres were found to be cytocompatible with both cell types and the best results (i.e. cell growth and gel electrical conductivity) were obtained with a low concentration (0.5 wt%) of PANI. After 7 days of culture in the conductive gels, the densities of both cell types were similar and comparable to collagen positive controls. Moreover, PC-12 cells were found to differentiate in the conductive hydrogels without the addition of nerve growth factor or electrical stimulation better than collagen control. Importantly, electrical conductivity of the three-dimensional gel scaffolds increased by more than 400% compared with control. The increased conductivity and injectability of the cell-laden collagen gels to injury sites in order to create an electrically conductive extracellular matrix makes these biomaterials very conducive for the regeneration of tissues.

APA, Harvard, Vancouver, ISO, and other styles

50

Ahn, Junho, Byeongho Park, Jongsoon Kim, Moon-Kwang Um, Jin Woo Yi, and Jung-Keun Yoo. "Multifunctional Additives for High-Energy-Density Lithium-Ion Batteries: Improved Conductive Additive/Binder Networks and Enhanced Electrochemical Properties." ACS Applied Materials & Interfaces 13, no. 17 (April 21, 2021): 19970–82. http://dx.doi.org/10.1021/acsami.1c00848.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Additifs de conduction'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles