INFLUENCE OF FLOWING PARAMETER OF MAGNETORHEOLOGICAL POLISHING FLUIDS (MRPF) ON THE QUALITY OF PROCESSING POLYCRYSTALLINE GLASS CERAMICS

2011 ◽  
Author(s):  
G. GORODKIN ◽  
Z. NOVIKOVA
Keyword(s):  
Glass Ceramics ◽  
Magnetorheological Polishing

Influence of flowing parameter of magnetorheological polishing fluids (MRPFs) on the quality of processing polycrystalline glass ceramics

2011 ◽  
Vol 23 (9) ◽  
pp. 959-962 ◽  
Author(s):  
Gennadi Gorodkin ◽  
Zoya Novikova
Keyword(s):  
Glass Ceramics ◽  
Root Mean Square Roughness ◽  
Magnetorheological Finishing ◽  
Abrasive Particles ◽  
Atomic Force ◽  
Finishing Process ◽  
Surface Measurements ◽  
Magnetorheological Polishing ◽  
Diamond Abrasive

The study of rheological characteristics for two types of magnetorheological polishing fluids (MRPFs), MRPF-1 based on cerium oxide abrasive particles and MRPF-2 based on nano-diamond abrasive particles, was carried out. Experiments on polishing of a polycrystalline sitall laser mirror substrates with these fluids using magnetorheological finishing process were executed. The surface structure of the samples after the polishing was investigated with the atomic force microscope. The results of surface measurements for the samples under the study polished with both MRPF-1 and MRPF-2 fluids are reported in comparison with the existed data obtained from a regular pitch polishing method. The lowest root-mean-square roughness of 0.2–0.4 nm was obtained for the samples polished with MRPF-2.

scholarly journals Effect of particle sizes and sodium hydroxide concentrations on silica extraction from minerals obtained in Kalirejo village, Kokap, Kulonprogo, Yogyakarta

Eksergi ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 29
Author(s):  
Tutik Muji Setyoningrum ◽  
Wibiana Wulan Nandari ◽  
Sri Wahyu Murni ◽  
Muhamad Maulana Azimatun Nur
Keyword(s):  
Particle Size ◽  
Glass Ceramics ◽  
Extraction Process ◽  
Extraction Yield ◽  
Liquid Extraction ◽  
Refining Process ◽  
Particle Sizes ◽  
Small Communities ◽  
Solid Liquid

Silica is mainly used in the production of rubber, glass, cement, glass, ceramics, paper, cosmetics, electronics, paintings, healthcare and other industries. Kalirejo village has a potential abundant resource of silica minerals. However, to refine it, high cost of extraction should be done to obtain high purity of silica. Different refining methods influence different purity of the silica. The purpose of this research was to study the refining process of mineral rock silica from Kalirejo village, Kokap, Kulonprogo by emplying simple and cheap solid-liquid extraction. Extraction was done by varying the particle size at 100 - 200 mesh, while NaOH concentration was varied in 0.5 N to 5 N.  Results showed that minerals taken from Kalirejo village was dominated by silica (23%).  The largest extract (4.89 gram) was obtained at 200 mesh and using NaOH 5 N with yield of 15.07%. Higher NaOH and higher particle size enhanced the extraction yield. This finding could help small communities in Kalirejo village to enhance the quality of silica by employing simple and cheap extraction process.

Applications of bauxite residue: A mini-review

2017 ◽  
Vol 35 (10) ◽  
pp. 999-1012 ◽  
Author(s):  
Ajay S Verma ◽  
Narendra M Suri ◽  
Suman Kant
Keyword(s):  
Automobile Industry ◽  
Bauxite Residue ◽  
Glass Ceramics ◽  
Large Area ◽  
Alumina Production ◽  
Mineralogical Characteristics ◽  
Valuable Metals ◽  
High Alkalinity ◽  
Bauxite Ore

Bauxite residue is the waste generated during alumina production by Bayer’s process. The amount of bauxite residue (40–50 wt%) generated depends on the quality of bauxite ore used for the processing. High alkalinity and high caustic content in bauxite residue causes environmental risk for fertile soil and ground water contamination. The caustic (NaOH) content in bauxite residue leads to human health risks, like dermal problems and irritation to eyes. Moreover, disposal of bauxite residue requires a large area; such problems can only be minimised by utilising bauxite residue effectively. For two decades, bauxite residue has been used as a binder in cement industries and filler/reinforcement for composite materials in the automobile industry. Valuable metals and oxides, like alumina (Al2O3), titanium oxide (TiO2) and iron oxide Fe2O3, were extracted from bauxite residue to reduce waste. Bauxite residue was utilised in construction and structure industries to make geopolymers. It was also used in the making of glass-ceramics and a coating material. Recently bauxite residue has been utilised to extract rare earth elements like scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd) and dysprosium (Dy). In this review article, the mineralogical characteristics of bauxite residue are summarised and current progresses on utilisation of bauxite residue in different fields of science and engineering are presented in detail.

scholarly journals Towards the High Phase Purity of Nanostructured Alluaudite-Type Glass-Ceramics Cathode Materials for Sodium Ion Batteries

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4997
Author(s):  
Maciej Nowagiel ◽  
Mateusz J. Samsel ◽  
Tomasz K. Pietrzak
Keyword(s):  
Cathode Materials ◽  
Glass Ceramics ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Microscopy Imaging ◽  
Phase Purity ◽  
High Phase Purity ◽  
High Phase

Alluaudite-type materials are systematically attracting more attention as prospective cathode materials for sodium ion batteries. In this paper, we strove to optimize various synthesis parameters of three alluaudite compositions (Na2Fe3(PO4)3—FFF, Na2VFe2(PO4)3—VFF, and Na2VFeMn(PO4)3—VFM) to obtain nanostructured alluaudite-type glass-ceramics with high phase purity. We systematically investigated the role of the chemical reactions, temperature and time of melting, cooling rate, and reducing factors on the quality of the final products. A detailed synthesis protocol along with X-ray diffractometry, thermal analysis, scanning electron microscopy imaging, and electrical conductivity measurements (with impedance spectroscopy) are reported. As a result, a significant increase of the conductivity was observed in the nanomaterials. The highest value was reached for the VFF composition and was equal to 6×10−4 S/cm at room temperature.

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.

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