Carbyne Forms of Carbon: Do They Exist?

Science ◽  
1982 ◽  
Vol 216 (4549) ◽  
pp. 984-986 ◽  
Author(s):  
P. P. K. SMITH ◽  
P. R. BUSECK
Keyword(s):  
Forms Of Carbon

A standard for transmission electron spectroscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 530-531 ◽  
Author(s):  
Dennis Maher ◽  
David Joy ◽  
Peggy Mochel
Keyword(s):  
Thin Films ◽  
Electron Spectroscopy ◽  
Host Lattice ◽  
Single Element ◽  
Multicomponent Systems ◽  
Transmission Electron ◽  
Major Interest ◽  
Standard Specimens ◽  
Forms Of Carbon ◽  
Electron Energy Loss

A variety of standard specimens is needed in order to systematically investigate the instrumentation, specimen, data reduction and quantitation variables in electron energy-loss spectroscopy (EELS). Pure single element specimens (e.g. various forms of carbon) have received considerable attention to date but certain elements of interest cannot be prepared directly as thin films. Since studies of the first and second row elements in two- or multicomponent systems will be of considerable importance in microanalysis using EELS, there is a need for convenient standards containing these species. For many investigations a standard should contain the desired element, or elements, homogeneously dispersed through a suitable matrix and at an accurately known concentration. These conditions may be met by the technique of implantation.Silicon was chosen as the host lattice since its principal ionization energies, EL23 = 98 eV and Ek = 1843 eV, are well removed from the K-edges of most elements of major interest such as boron (Ek = 188 eV), carbon (Ek = 283 eV), nitrogen (Ek = 400 eV) and oxygen (Ek = 532 eV).

scholarly journals Effects of different returning method combined with decomposer on decomposition of organic components of straw and soil fertility

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Wang ◽  
Xuexin Wang ◽  
Peng Geng ◽  
Qian Yang ◽  
Kun Chen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Fertility ◽  
Decomposition Rate ◽  
Microbial Biomass Carbon ◽  
No Tillage ◽  
Short Term ◽  
Straw Decomposition ◽  
Short Period ◽  
Straw Return ◽  
Forms Of Carbon

AbstractIn view of the problems of low straw decomposition rates and reduced soil fertility in southern Liaoning, China, we investigated the effects of no-tillage mode (NT), deep loosening + deep rotary tillage mode (PT), rotary tillage mode (RT) and the addition of decomposing agent (the next is called a decomposer) (NT + S, PT + S, RT + S) on the decomposition proportion of straw, respectively, by using the nylon net bag method in combination with 365-day field plot experiments. The decomposition rules of cellulose, hemicellulose and lignin as well as the dynamics of soil organic carbon (SOC), soil microbial biomass carbon (MBC) and soil dissolved organic carbon (DOC) in straw returned to the field for 15, 35, 55, 75, 95, 145 and 365 days were analyzed. The results showed that in the short term, the decomposition of straw was better in both the rotray tillage and deep loosening + deep rotary modes than in the no-tillage mode, and the addition of decomposer significantly promoted the decomposition of straw and the release of carbon from straw, among them, the RT + S treatment had the highest straw decomposition proportion and carbon release proportion in all sampling periods. After a one year experimental cycle, the RT + S treatment showed the highest proportion of cellulose, hemicellulose and lignin decomposition with 35.49%, 84.23% and 85.50%, respectively, and soil SOC, MBC and DOC contents were also higher than the other treatments with an increase of 2.30 g kg−1, 14.22 mg kg−1 and 25.10 mg kg−1, respectively, compared to the pre-experimental soil. Our results show that in the short term, to accelerate the decomposition rate of returned straw and increase the content of various forms of carbon in soil, rotary tillage can be used to return the straw to the field, while also spraying straw decomposer on its surface. This experiment used a new straw decomposer rich in a variety of microorganisms, combined with the comparison of a variety of straw return modes, and in-depth study of straw decomposition effects of cellulose, hemicellulose and lignin. Thus, a scheme that can effectively improve the decomposition rate of straw and the content of various forms of organic carbon in soil within a short period of time was explored to provide theoretical support for the southern Liaoning.

Microstructure of Carbon Black

1964 ◽  
Vol 37 (5) ◽  
pp. 1245-1298 ◽  
Author(s):  
F. A. Heckman
Keyword(s):  
Carbon Black ◽  
Gas Adsorption ◽  
Current Knowledge ◽  
Aggregate Size ◽  
Surface Characteristics ◽  
The Body ◽  
Degree Of Crystallinity ◽  
Complete Treatment ◽  
Real Value ◽  
Forms Of Carbon

Abstract Although the microstructure of carbon black has been under investigation for more than fifty years, there are still many aspects which are controversial and some which are virtually unexplored. The inherently low degree of crystallinity and the finely-divided state of carbon blacks have greatly hindered efforts to understand them. The purpose of this article is to cite the principal contributors to our understanding of carbon black microstructure, to discuss the significance of their contribution, to present a clear picture of the present state of our knowledge, and to note areas where controversy exists and where our knowledge is incomplete. The scope of this article is necessarily limited to a reasonably complete treatment of the several aspects of carbon black microstructure; that is, the arrangement of carbon atoms to form graphite layer planes, the arrangement of layer planes to form crystallites, and the arrangement of crystallites to form the more familiar carbon black “particles” or aggregates. Particular attention is paid to more recent articles and those which have shaped our thinking on carbon black microstructure. This article also includes a fairly complete review of various studies on the changes in microstructure which are brought about by heat treatment or oxidation. In general, the rather large number of studies reporting on the microstructure of other forms of carbon have not been reviewed (except for the work of Franklin whose contribution to our understanding of carbon-black microstructure is so immense that it must be included). Although gross, morphological features such as particle size, primary aggregate size and shape are studied briefly in order to relate them to microstructure, no effort was made to review comprehensively the body of literature pertinent to this subject. Also porosity and surface characteristics per se (as measured by gas adsorption techniques) are not treated in detail here. Rather than review a dreary list of papers which have only the slightest bearing on carbon black, the author has taken the liberty of dividing the articles reviewed into two categories. The first category, which is reviewed in some detail, includes those publications in which an important contribution was made to the understanding of carbon-black microstructure. The second category includes all those articles which are discussed only briefly or not at all because the authors have reported superficial or routine studies or they (probably unknown to them) have essentially duplicated the work of an earlier worker, or have reported uncorrected results which are thus so inaccurate as to be without real value to this article; or because they comprise work which is only peripherally related to carbon black microstructure. Also, references taken from other papers, but not reviewed here, are included in the latter category. Articles by Warren, Hofmann and Wilm, Steward and Cook and Walker contain bibliographies which will be helpful to those interested in the earlier work or in the microstructure of carbons other than carbon black. For the reader whose time is limited, an adequate picture of current understanding of carbon black microstructure can be gained by reading Sections II, IV, and V which are relatively short. Finally, a word about the spirit in which the review was written. At the request of the late Dr. Craig, a critical review was prepared in which every effort was made to point out shortcomings as well as classic contributions contained in the pertinent literature. Where the experts have disagreed, the reviewer, often with skill unequal to the task, has attempted to decide which one was the more correct in the light of current knowledge. It is with deep humility and great respect for those who have gone before that this review is submitted.

An ab initio investigation of the electronic and magnetic properties of graphite and nickel-doped graphite

2021 ◽  
Vol 93 (4) ◽  
pp. 40401
Author(s):  
Abdellah Sellam ◽  
El Kebir Hlil ◽  
Rodolphe Heyd ◽  
Abdelaziz Koumina
Keyword(s):  
Magnetic Properties ◽  
Total Energy ◽  
Magnetic Moments ◽  
Structure Optimization ◽  
Crystallographic Structure ◽  
Ni Doping ◽  
Potential Approximation ◽  
Metallic Behavior ◽  
Electronic And Magnetic Properties ◽  
Forms Of Carbon

In this paper, the KKR (Korringa, Kohn, and Rostoker) is presented with coherent potential approximation methods which is used to investigate the electronic and magnetic properties of allotropic graphite forms of carbon and nickel-doped graphite. The density of states (DOS), band structure, total energy, and the magnetic moments of atoms are computed. The crystallographic structure optimization is carried out by evaluating the total energy as a function of unit lattice parameters. The DOS analysis reveals a partially metallic behavior of the compound. The magnetism vs the Ni-doping content in C1−xNix is also investigated by computing moments induced on atoms; the sensitivity of the magnetism to Ni-doping is also analyzed.

scholarly journals Reconstruction of Ovine Trachea with a Biomimetic Composite Biomaterial

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Wojciech Ścierski ◽  
Grażyna Lisowska ◽  
Grzegorz Namysłowski ◽  
Maciej Misiołek ◽  
Jan Pilch ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Nonwoven Fabric ◽  
Woven Fabric ◽  
Future Research ◽  
Histological Structure ◽  
Tracheal Reconstruction ◽  
Medical Needs ◽  
Forms Of Carbon

The aim of this study was to evaluate a novel composite material for tracheal reconstruction in an ovine model. A polymer containing various forms of carbon fibers (roving, woven, and nonwoven fabric) impregnated with polysulfone (PSU) was used to create cylindrical tracheal implants, 3 cm in length and 2.5 cm in diameter. Each implant, reinforced with five rings made of PSU-impregnated carbon-fiber roving, had three external layers made of carbon-fiber woven fabric and the inner layer formed of carbon-fiber nonwoven fabric. The inner surface of five implants was additionally coated with polyurethane (PU), to promote migration of respiratory epithelium. The implants were used to repair tracheal defects (involving four tracheal rings) in 10 sheep (9-12 months of age; 40-50 kg body weight). Macroscopic and microscopic characteristics of the implants and tracheal anastomoses were examined 4 and 24 weeks after implantation. At the end of the follow-up period, outer surfaces of the implants were covered with the tissue which to various degree resembled histological structure of normal tracheal wall. In turn, inner surfaces of the prostheses were covered only with vascularized connective tissue. Inner polyurethane coating did not improve the outcomes of tracheal reconstruction and promoted excessive granulation, which contributed to moderate to severe stenosis at the tracheal anastomoses. The hereby presented preliminary findings constitute a valuable source of data for future research on a tracheal implant being optimally adjusted for medical needs.

scholarly journals Uraemic Toxins Generated in the Presence of FullereneC60, Carbon-Encapsulated Magnetic Nanoparticles, and Multiwalled Carbon Nanotubes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Magdalena Popławska ◽  
Hanna Krawczyk
Keyword(s):  
Carbon Nanotubes ◽  
Magnetic Nanoparticles ◽  
Multiwalled Carbon Nanotubes ◽  
Conversion Degree ◽  
Multiwalled Carbon ◽  
Forms Of Carbon

Uraemic toxins—creatol and N-methylguanidine—are generated in conversion of creatinine in water in the presence of various forms of carbon such as fullerene C60, carbon-encapsulated magnetic nanoparticles, and multiwalled carbon nanotubes and oxygen. The conversion degree for creatinine was different for fullerene C60, CEMNPs, and MWCNTs and was 9% (3.6% creatol, 5.4% N-methylguanidine), 35% (12% creatol, 23% N-methylguanidine), and 75% (16% creatol, 59% N-methylguanidine), respectively.

New Forms of Carbon and New Opportunities

2014 ◽  
pp. 71-84
Author(s):  
Christian Ngô ◽  
Marcel H. Van de Voorde
Keyword(s):  
Forms Of Carbon

Conducting forms of Carbon

1999 ◽  
pp. 390-439
Author(s):  
L. Forró ◽  
A. Jánossy ◽  
D. Ugarte ◽  
Walt A. de Heer
Keyword(s):  
Forms Of Carbon

scholarly journals Carbon Nanotube Peapods Under High-Strain Rate Conditions: A Molecular Dynamics Investigation

MRS Advances ◽  
2020 ◽  
Vol 5 (33-34) ◽  
pp. 1723-1730
Author(s):  
J. M. De Sousa ◽  
C. F. Woellner ◽  
L. D. Machado ◽  
P. A. S. Autreto ◽  
D. S. Galvao
Keyword(s):  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Optical Modulation ◽  
Carbon Structures ◽  
Dynamics Simulations ◽  
Forms Of Carbon ◽  
The Impact

ABSTRACTNew forms of carbon-based materials have received great attention, and the developed materials have found many applications in nanotechnology. Interesting novel carbon structures include the carbon peapods, which are comprised of fullerenes encapsulated within carbon nanotubes. Peapod-like nanostructures have been successfully synthesized, and have been used in optical modulation devices, transistors, solar cells, and in other devices. However, the mechanical properties of these structures are not completely elucidated. In this work, we investigated, using fully atomistic molecular dynamics simulations, the deformation of carbon peapods under high-strain rate conditions, which are achieved by shooting the peapods at ultrasonic velocities against a rigid substrate. Our results show that carbon peapods experience large deformation at impact, and undergo multiple fracture pathways, depending primarily on the relative orientation between the peapod and the substrate, and the impact velocity. Observed outcomes include fullerene ejection, carbon nanotube fracture, fullerene, and nanotube coalescence, as well as the formation of amorphous carbon structures.

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