scholarly journals Carbon Black as Conductive Additive and Structural Director of Porous Carbon Gels

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 217
Author(s):  
Ana Casanova ◽  
Alicia Gomis-Berenguer ◽  
Aurelien Canizares ◽  
Patrick Simon ◽  
Dolores Calzada ◽  
...  
Keyword(s):  
Carbon Black ◽  
Carbon Matrix ◽  
Conductive Additive ◽  
Secondary Network ◽  
Porous Architecture ◽  
Carbon Gels ◽  
Mesopore Structure ◽  
Point To Point ◽  
Post Synthesis ◽  
The Impact

This work investigates the impact of carbon black (CB) as a porogenic agent and conductive additive in the preparation of electrically conductive nanoporous carbon gels. For this, a series of materials were prepared by the polycondensation of resorcinol/formaldehyde mixtures in the presence of increasing amounts of carbon black. The conductivity of the carbon gel/CB composites increased considerably with the amount of CB, indicating a good dispersion of the additive within the carbon matrix. A percolation threshold of ca. 8 wt.% of conductive additive was found to achieve an adequate “point to point” conductive network. This value is higher than that reported for other additives, owing to the synthetic route chosen, as the additive was incorporated in the reactant’s mixture (pre-synthesis) rather than in the formulation of the electrodes ink (post-synthesis). The CB strongly influenced the development of the porous architecture of the gels that exhibited a multimodal mesopore structure comprised of two distinct pore networks. The microporosity and the primary mesopore structure remained rather unchanged. On the contrary, a secondary network of mesopores was formed in the presence of the additive. Furthermore, the average mesopore size and the volume of the secondary network increased with the amount of CB.

Polyol Synthesis of Lithium Iron Phosphate with Carbon Nanotubes: Effect of Dispersion on Crystallinity and Electrochemical Performance

2014 ◽  
Vol 1678 ◽  
Author(s):  
Wesley D. Tennyson
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Polyol Synthesis ◽  
Battery Life ◽  
Unique Challenge ◽  
Weight Percentage ◽  
Conductive Additive ◽  
Power Capability

ABSTRACTCarbon nanotubes (CNTs) have been shown to be a viable conductive additive in Li-Ion batteries [1]. By using CNTs battery life, energy, and power capability can all be improved over carbon black, the traditional conductive additive. A significantly smaller weight percentage (5% CNTs) is needed to get the same conductivity as 20% carbon black. Many of the previous efforts found that a combination of conductive additives was most advantageous [2]. Unfortunately many of these efforts did not attend to the unique challenge that dispersing nanotubes presents and used non-optimal methods to disperse CNTs (e.g. ball milling) [3,4]. With poor dispersion a stable and resilient conductive network in the cathode is hard to form with CNTs alone. Here we investigate the formation of LiFePO₄ with CNTs using a polyol process synthesis.

Abstract P324: Unhealthy Diet and Air Pollution Compromise Human Cardiovascular Cell Functions: A First Mechanistic Analysis

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Niloofar Ale-Agha ◽  
Nicole Buechner ◽  
Ulrich Sydlik ◽  
Klaus Unfried ◽  
Joachim Altschmied ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cardiovascular Diseases ◽  
Carbon Black ◽  
Ultrafine Particles ◽  
Culture Media ◽  
Density Lipoprotein ◽  
Cell Functions ◽  
Unhealthy Diet ◽  
Cardiovascular Aging ◽  
The Impact

Diet and pollution are environmental factors known to compromise ″healthy cardiovascular aging″. The molecular consequences of the permanent burden for aging of the cardiovascular system are unknown, since they have never been examined in primary, adult human cells. Therefore, this study investigates the impact of unhealthy diet on aging-related signaling pathways of human, primary cardiovascular cells and of airborne particles on human endothelial cells, as several studies demonstrated that ultrafine particles can enter the circulation and thus may interact with endothelial cells directly. Nutrition health reports have shown that the diet in industrialized countries contains more than 100 mg/dl low density lipoprotein (LDL) and a too high fraction of monosaccharides, especially fructose, which is metabolized insulin-independently. Both components have been shown to increase the risk for cardiovascular diseases. To simulate unhealthy diet we supplemented cell culture media of human, primary endothelial cells (EC), smooth muscle cells (SMC) and cardiomyocytes (CM) with 100 mg/dl LDL and replaced 1/3 of the glucose with fructose for one week. This treatment did not induce cell death in any of the cell types. However, we observed increased senescence, loss of endothelial nitric oxide synthase and increased nuclear localization of Foxo3 in EC, increased proliferation in SMC and hypertrophy in CM. With respect to pollution we have used ultrafine carbon black particles (ufCB), one of the major constituents of industrial and exhaust emissions, in concentrations our vessels are constantly exposed to. These concentrations of ufCB are non-toxic and non-inflammatory for EC. Despite these missing immediate effects, ufCB dramatically reduced the S-NO content, a marker for NO-bioavailability in EC and increased reactive oxgen species formation. As a consequence, ufCB dramatically increased senescence of EC after two weeks. Thus, unhealthy diet and a high burden of ultrafine carbon black nanoparticles, to which we are exposed every day, seem to induce a ″cardiovascular aging″ phenotype and can lead to severe cardiovascular diseases.

PENETRATION RESISTANCE OF RUBBER VULCANIZATES

2020 ◽  
Vol 93 (4) ◽  
pp. 704-728
Author(s):  
Anil K. Bhowmick ◽  
Subhabrata Saha ◽  
Anshul Baral ◽  
Kumar Vineet ◽  
Arup S. Deuri ◽  
...  
Keyword(s):  
Carbon Black ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Fracture Initiation ◽  
Penetration Resistance ◽  
Theoretical Interpretation ◽  
Initiation Point ◽  
Static Test ◽  
Rubber Compounds ◽  
The Impact

ABSTRACT Aspects of penetration resistance of rubber compounds have been studied by developing a quasi-static test. The effects of indenter material and design, nature and dosage of fillers, and crosslinking density were investigated. Indenter material was found to have a negligible contribution to the penetration characteristics of the rubber compounds, whereas the conical indenter's shape and size of the tip were important. A change in the slope of the generalized penetration characteristic curve of the developed quasi-static test was considered to be the fracture initiation point. Although fracture initiation was early at higher carbon black loading, the overall penetration resistance was improved due to hysteresis, which was in accord with the impact energy method. This was a unique observation. The carbon black–filled sample was compared with the silica-filled vulcanizate. Surface morphology of the specimens penetrated at different energy levels was examined using scanning electron microscopy. A theoretical interpretation of the forces acting at the tip of the indenter and the energy requirement while penetrating a rubber compound against a conical indenter has been proposed. The initiation energy for penetration has inverse square root dependence on the Young's modulus of the compounds. The energy required for crack propagation in contrast, was directly proportional to the Young's modulus and also correlated with the hysteresis loss and frictional coefficient for the carbon black–filled vulcanizates.

scholarly journals Less than the sum of its parts: the dust-corrected H α luminosity of star-forming galaxies explored at different spatial resolutions with MaNGA and MUSE

2020 ◽  
Vol 498 (3) ◽  
pp. 4205-4221
Author(s):  
N Vale Asari ◽  
V Wild ◽  
A L de Amorim ◽  
A Werle ◽  
Y Zheng ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Formation Rate ◽  
Flux Ratio ◽  
Star Forming ◽  
The Galaxy ◽  
Nearby Galaxies ◽  
Point To Point ◽  
Dust Attenuation ◽  
The Impact ◽  
Lower Limits

ABSTRACT The H α and H β emission-line luminosities measured in a single integrated spectrum are affected in non-trivial ways by point-to-point variations in dust attenuation in a galaxy. This work investigates the impact of this variation when estimating global H α luminosities corrected for the presence of dust by a global Balmer decrement. Analytical arguments show that the dust-corrected H α luminosity is always underestimated when using the global H α/H β flux ratio to correct for dust attenuation. We measure this effect on 156 face-on star-forming galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey. At 1–2 kpc spatial resolution, the effect is small but systematic, with the integrated dust-corrected H α luminosity underestimated by 2–4 per cent (and typically not more than by 10 per cent), and depends on the specific star formation rate of the galaxy. Given the spatial resolution of MaNGA, these are lower limits for the effect. From Multi Unit Spectroscopic Explorer (MUSE) observations of NGC 628 with a resolution of 36 pc, we find the discrepancy between the globally and the point-by-point dust-corrected H α luminosity to be 14 ± 1 per cent, which may still underestimate the true effect. We use toy models and simulations to show that the true difference depends strongly on the spatial variance of the H α/H β flux ratio, and on the slope of the relation between H αluminosity and dust attenuation within a galaxy. Larger samples of higher spatial resolution observations are required to quantify the dependence of this effect as a function of galaxy properties.

Pre-Test Evaluation of Probe Configuration Errors

2019 ◽  
Author(s):  
John Gillespie ◽  
Dustin Frohnapfel ◽  
Walter O’Brien
Keyword(s):  
Total Pressure ◽  
Flow Property ◽  
Test Time ◽  
Test Evaluation ◽  
Flow Profile ◽  
Flow Distortion ◽  
Turbine Engine ◽  
Point To Point ◽  
The Cost ◽  
The Impact

Abstract Rake probes are commonly used in turbomachinery applications to measure distorted inlet flows, including both pressure and swirl distortions. An especially common configuration is the 40 probe rake array, consisting of eight identical arms equally spaced circumferentially around the inlet, each arm having five sensing locations spaced along centers of equal area. By measuring many locations simultaneously, rake probes have the advantage of expedited data collection when compared to traversing probes. However, this reduction in test time comes at the cost of rigid geometry with limited measurement locations. As a result, it is possible for rake probes to miss or exaggerate significant areas of the flow profile, such as large gradients or small features, based on the fixed location of the probe and the particular details of the distortion. The purpose of this paper is to demonstrate a procedure that can be used to evaluate the ability of any desired probe configuration (40 probe rake or otherwise) to sufficiently and accurately measure a non-uniform flow profile. Results of this procedure for a range of profiles and probe configurations are also presented. In order to accurately determine the impact of discrete sampling on the results, two broad sets of data were generated numerically and analyzed. The first set consists of four fundamental total pressure distortions: once-per-rev circumferential, twice-per-rev circumferential, hub radial, and tip radial. The second set consists of three realistic turbofan distortion patterns: two analytic (though not fundamental) profiles, and one generated from S-duct computational results. For all investigated patterns, Radial Distortion Intensity and Circumferential Distortion Intensity are calculated in the manner described by ARP 1420, a guideline issued by the S-16 Turbine Engine Inlet Flow Distortion Committee for measuring total pressure distortions in turbomachinery. Additionally, interpolated total pressure contours are generated for each measurement configuration. These were then used to make point-to-point comparisons between the actual and estimated data. While total pressure distortion was used as the variable of interest for the majority of this paper, the conclusions may be applied to swirl, temperature, or any other flow property measured using a probe rake or traversing probe.

scholarly journals Effect of Carbon Additives on the Electrochemical Performance of Li4Ti5O12/C Anodes

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3941
Author(s):  
Irina Stenina ◽  
Ruslan Shaydullin ◽  
Tatiana Kulova ◽  
Anna Kuz’mina ◽  
Nataliya Tabachkova ◽  
...  
Keyword(s):  
Carbon Black ◽  
Electrochemical Performance ◽  
Rate Capability ◽  
Carbon Matrix ◽  
X Ray Diffraction ◽  
Discharge Rates ◽  
Transmission Electron ◽  
Carbon Additives ◽  
Promising Application ◽  
Carbon Replicas

The Li4Ti5O12/C composites were prepared by a hydrothermal method with in situ carbon addition. The influence of the morphology and content of various carbon materials (conductive carbon black, mesoporous carbon G_157M, and carbon replicas) on the electrochemical performance of the Li4Ti5O12/C composites was investigated. The obtained composites were characterized using X-ray diffraction, scanning electron microsopy, high-resolution transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy, and N2 sorption-desorption isotherms. Morphology of the Li4Ti5O12/C composites depends on the carbon matrix used, while both morphology and the amount of carbon material have a great impact on the rate capability and cycling stability of the obtained composites. At low current densities, the Li4Ti5O12/C composite with 5 wt.% G_157M exhibits the highest discharge capacity, while at high charge-discharge rates, the Li4Ti5O12/carbon black composites show the best electrochemical performance. Thus, at ~0.1C, 5C, and 18C rates, the discharge capacities of the obtained Li4Ti5O12/C composites are 175, 120, and 70 mAh/g for G_157M, 165, 126, and 78 mAh/g for carbon replicas, and 173, 128, and 93 mAh/g for carbon black. After 100 cycles, their capacity retention is no less than 95%, suggesting their promising application perspective.

Effects of tension fatigue on the structure and properties of carbon black filled-SBR and SBR/TPI blends

2019 ◽  
Vol 40 (1) ◽  
pp. 13-20
Author(s):  
Liu Yang ◽  
Kaikai Liu ◽  
Zijun Gu ◽  
Aihua Du
Keyword(s):  
Carbon Black ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Dynamic Properties ◽  
Fatigue Properties ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Structure And Properties ◽  
Tan Δ ◽  
The Impact

Abstract The aim of this study was to explore the impact of tension fatigue on the structure and properties of filled SBR and SBR/TPI blends. The effect of tension fatigue on the dynamic properties of carbon black-filled styrene-butadiene rubber (SBR) and SBR/trans-1,4-polyisoprene (SBR/TPI) blend vulcanizates were investigated by dynamic mechanical analysis (DMA). The Mooney-Rivlin analysis of tensile stress-strain data is used for the determination of a rubber network crosslink density. The fatigue fracture surface of SBR/TPI vulcanizates was observed with a scanning electron microscopy (SEM). The crystallinity of TPI in carbon black-filled SBR/TPI (80/20) was characterized by X-ray diffraction (XRD). The results showed that the incorporation of TPI into SBR vulcanizates influences the fatigue properties of the blend vulcanizates. The blend vulcanizates showed optimum fatigue properties with 20 phr TPI. With increasing fatigue cycles, the tensile properties and crosslink density of SBR vulcanizates were decreased substantially. Compared with that of SBR vulcanizates, the tensile properties and crosslink density of SBR/TPI (80/20) blend vulcanizates changed little with the increase in fatigue cycles, and tan δ and E′ decreased gradually with the fatigue cycles. There was a sharp decrease in the E′ and tan δ curve in the temperature range of 40 ~ 60°C. The XRD diffraction peak corresponding to 3.9 Å broadened when the fatigue cycles were increased to 1 million times, and a new peak with inter-planar spacing at 7.6 and 4.7 Å appeared.

INFLUENCE OF TRAFFIC CORRELATION ON THE PERFORMANCE OF NETWORK-ON-CHIP DESIGNS

2010 ◽  
Vol 19 (03) ◽  
pp. 655-669 ◽  
Author(s):  
FANG WANG
Keyword(s):  
High Speed ◽  
Communication Complexity ◽  
Network On Chip ◽  
Strong Correlations ◽  
Communication Performance ◽  
Seamless Integration ◽  
High Speed Network ◽  
On Chip ◽  
Point To Point ◽  
The Impact

Advance in semiconductor technologies enables seamless integration of hundreds of cores on a single silicon die, which requires high communication performance. To deal with the increasing communication complexity of System-on-Chip (SoC), Network-on-Chip (NoC) has been recently proposed as an alternative to the conventional point-to-point links and bus based communication fabrics. In practice, to facilitate NoC design evaluation and optimization, Poisson traffic or Bernoulli traffic models are generally assumed. However, actual measurements showed that real high speed network traffic always has strong correlations. The objective of this paper is to investigate the impact of traffic correlations on the performance of NoC design. Experimental results show that traffic correlation degrades the performance of NoC design and unrealistic traffic assumptions may yield unacceptable designs.

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