scholarly journals Improvements to quality of needle coke by controlled carbonized conditions

2018 ◽  
Author(s):  
Dong Liu ◽  
Bin Lou ◽  
Ran Yu ◽  
Qingtai Chen ◽  
Zhiheng Li ◽  
...  
Keyword(s):  
Needle Coke

Influence of heating rate on quality of needle coke in calcining

1983 ◽  
Vol 19 (9) ◽  
pp. 437-440
Author(s):  
M. M. Akhmetov ◽  
N. N. Karpinskaya ◽  
N. N. Shipkov
Keyword(s):  
Heating Rate ◽  
Needle Coke

scholarly journals Obtaining coke of improved quality by hydro-gentrification of coal tar

2021 ◽  
Vol 340 ◽  
pp. 01034
Author(s):  
Nazym Smagulova ◽  
Zhaxyntay Kairbekov ◽  
Gulsezim Yermekbayeva
Keyword(s):  
Water Content ◽  
Boiling Point ◽  
Nickel Sulfide ◽  
Catalytic Properties ◽  
Coal Tar ◽  
Processing Technology ◽  
Sulfide Catalysts ◽  
Mass Ratio ◽  
Needle Coke

The catalytic properties of non-applied nickel-sulfide catalysts in the reactions of hydrogenation and hydrodesulphurization of coal tar from the coal semi-coking of the Shubarkul field (Republic of Kazakhstan) were studied to obtain data necessary for the intensification of the resin processing technology, increasing the yield and improving the quality of the resulting needle coke. As a feedstock, the resin was used without preliminary dehydration (water content 3.4 %) and distillation in a mixture with the prepared catalyst and the residue of distillation with boiling point above 320°C of oil from the Kumkol field (Republic of Kazakhstan), taken in a mass ratio of 1:1.

scholarly journals Molybdenum Carbide and Sulfide Nanoparticles as Selective Hydrotreating Catalysts for FCC Slurry Oil to Remove Olefins and Sulfur

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2721
Author(s):  
He Liu ◽  
Zhipeng Qiu ◽  
Huihui Pan ◽  
Aijun Guo ◽  
Shouhui Jiao ◽  
...  
Keyword(s):  
Molybdenum Carbide ◽  
Structural Parameters ◽  
Ammonium Molybdate ◽  
Spot Test ◽  
Needle Coke ◽  
The Real ◽  
Hydrotreating Catalysts ◽  
The Stability ◽  
Bromine Number

As the two types of major impurities in FCC slurry oil (SLO), olefins and sulfur seriously deteriorate the preparation and quality of mesophase pitch or needle coke. The development of a hydrotreatment for SLO to remove olefins and sulfur selectively becomes imperative. This work presents the potentiality of dispersed Mo2C and MoS2 nanoparticles as selective hydrotreating catalysts of SLO. Mo2C was synthesized by the carbonization of citric acid, ammonium molybdate and KCl mixtures while MoS2 was prepared from the decomposition of precursors. These catalysts were characterized by XRD, HRTEM, XPS, BJH, BET, and applied to the hydrotreating of an SLO surrogate with defined components and real SLO. The conversion of olefins, dibenzothiophene and anthracene in the surrogate was detected by GC-MS. Elemental analysis, bromine number, diene value, 1H-NMR and spot test were used to characterize the changes of the real SLO. The results show that hydrotreating the SLO surrogate with a very small amount of Mo-based nanoparticles could selectively remove olefins and sulfur without the overhydrogenation of polyaromatics. Mo2C exhibited much better activity than MoS2, with 95% of olefins and dibenzothiophene in the surrogate removed while only 15% anthracene was hydrogenated. The stability of the real SLO was significantly improved. Its structural parameters changed subtly, proving the aromatic macromolecules had been preserved.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

The Current Situation in Chemical Stabilization of Biological Materials

1972 ◽  
Vol 30 ◽  
pp. 132-133
Author(s):  
John H. Luft
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Molecular Level ◽  
Cross Linking ◽  
Chemical Stabilization ◽  
Specimen Preparation ◽  
Sufficient Condition ◽  
Radio Telescopes

With information processing devices such as radio telescopes, microscopes or hi-fi systems, the quality of the output often is limited by distortion or noise introduced at the input stage of the device. This analogy can be extended usefully to specimen preparation for the electron microscope; fixation, which initiates the processing sequence, is the single most important step and, unfortunately, is the least well understood. Although there is an abundance of fixation mixtures recommended in the light microscopy literature, osmium tetroxide and glutaraldehyde are favored for electron microscopy. These fixatives react vigorously with proteins at the molecular level. There is clear evidence for the cross-linking of proteins both by osmium tetroxide and glutaraldehyde and cross-linking may be a necessary if not sufficient condition to define fixatives as a class.

Resistance Monitor and Control for Vacuum Evaporation of Metals and Carbon

1976 ◽  
Vol 34 ◽  
pp. 572-573
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley
Keyword(s):  
Electronic Device ◽  
Point Sources ◽  
High Contrast ◽  
Variable Resistor ◽  
Quality Of Results ◽  
Low Contrast ◽  
Evaporation Source ◽  
And Control ◽  
At Will

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.

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