scholarly journals THE EFFECT OF LIQUID GLASS ON THE DEFORMATION OF REFRACTORY BINDER/SKYSTOJO STIKLO ĮTAKA KAITRAI ATSPARAUS RIŠIKLIO DEFORMACIJOMS

2001 ◽  
Vol 7 (1) ◽  
pp. 29-33
Author(s):  
Valentin Antonovič ◽  
Stasys Goberis
Keyword(s):  
High Temperature ◽  
Structure Formation ◽  
Liquid Glass ◽  
Structural Changes ◽  
Solid Phase ◽  
Refractory Materials ◽  
X Rays ◽  
Close Relationship ◽  
Ferrochrome Slag

The structure formation of a refractory binder of liquid glass, ferrochrome slag and dispersed chamotte has been studied. It has been found that there is a close relationship between the density of liquid glass used and sharp expansion of binder at the temperature of 500–600 °C: the lower the density, the lower the expansion of the material. To find the reason for this deformation of a binder, the specimens of dried out liquid glass (sodium hydro silicates) heating tests (Fig 1) and the specimens of dried out mixtures of liquid glass and some inert refractory materials (Table 2) dilatometric tests (Fig 2) have also been made. This investigation showed that sodium hydro silicates films bloated during heating. In order to determine structural changes under high temperature, X-rays investigation of refractory binder was made (Fig 5). This investigation showed that the reaction at the solid phase starts at the temperature over 600 °C and had no effect on the deformation of binder at 500–600 °C. It has been shown that the deformations occurring at 500–600 °C are caused by bloating of sodium hydro silicates (non-reacted liquid glass during hardening) films of the binder.

Identification of a Coronavirus Hemagglutinin-Esterase with a Substrate Specificity Different from Those of Influenza C Virus and Bovine Coronavirus

1999 ◽  
Vol 73 (5) ◽  
pp. 3737-3743 ◽  
Author(s):  
Alfred Klausegger ◽  
Birgit Strobl ◽  
Gerhard Regl ◽  
Alexandra Kaser ◽  
Willem Luytjes ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Solid Phase ◽  
Hepatitis Virus ◽  
Bovine Brain ◽  
Brain Extract ◽  
Binding Assays ◽  
Bovine Coronavirus ◽  
Close Relationship ◽  
Influenza C Virus ◽  
Cloned Gene

ABSTRACT We have characterized the hemagglutinin-esterase (HE) of puffinosis virus (PV), a coronavirus closely related to mouse hepatitis virus (MHV). Analysis of the cloned gene revealed approximately 85% sequence identity to HE proteins of MHV and approximately 60% identity to the corresponding esterase of bovine coronavirus. The HE protein exhibited acetylesterase activity with synthetic substratesp-nitrophenyl acetate, α-naphthyl acetate, and 4-methylumbelliferyl acetate. In contrast to other viral esterases, no activity was detectable with natural substrates containing 9-O-acetylated sialic acids. Furthermore, PV esterase was unable to remove influenza C virus receptors from human erythrocytes, indicating a substrate specificity different from HEs of influenza C virus and bovine coronavirus. Solid-phase binding assays revealed that purified PV was unable to bind to sialic acid-containing glycoconjugates like bovine submaxillary mucin, mouse α1macroglobulin or bovine brain extract. Because of the close relationship to MHV, possible implications on the substrate specificity of MHV esterases are suggested.

NEUTRON POWDER DIFFRACTION AND OXIDE SUPERCONDUCTORS

1993 ◽  
Vol 07 (16n17) ◽  
pp. 3077-3093 ◽  
Author(s):  
A.W. HEWAT
Keyword(s):  
Heavy Metals ◽  
High Temperature ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Oxide Superconductors ◽  
X Rays ◽  
New Materials ◽  
Oxidation Reduction ◽  
High Temperature Oxide ◽  
Temperature Oxide

Neutron powder diffraction has been essential for understanding the structures of the new high temperature oxide superconductors because of the difficulty in locating oxygen with X-rays in the presence of heavy metals, especially when single crystals are usually not available. This understanding lead to the discovery of new materials. In this paper we will show how it also sheds light on the crystal chemistry of oxide superconductors—the effects of oxidation/reduction, phase separation, pressure etc.

Bulk changes and structure formation in solid-phase sintering of Ti−TiAl3 powder mixtures

2008 ◽  
Vol 47 (11-12) ◽  
pp. 687-692 ◽  
Author(s):  
G. A. Pribytkov ◽  
I. A. Andreeva ◽  
V. V. Korzhova
Keyword(s):  
Structure Formation ◽  
Solid Phase ◽  
Powder Mixtures

Modification of Barium Cerate by Heavy Ion Irradiation

2013 ◽  
Vol 781-784 ◽  
pp. 357-361 ◽  
Author(s):  
Igor V. Khromushin ◽  
Taтiana I. Aksenova ◽  
Turgora Tuseyev ◽  
Karlygash K. Munasbaeva ◽  
Yuri V. Ermolaev ◽  
...  
Keyword(s):  
Structural Changes ◽  
Solid Phase ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Low Energy ◽  
Barium Cerate ◽  
Weakly Bound ◽  
Ion Ranges ◽  
High Energy Ions

The effect of irradiation with heavy ions Ne, Ar, and Kr of various energies on the structure and properties of ceramic barium cerate doped with neodymium and annealed in air at 650°C for 7 hours is studied. It is noted that blistering was observed on cerate surface during its irradiation by low energy Ne ions, whereas it was not observed under low-energy Ar and Kr ions irradiation. Irradiation of the cerate with high energy ions caused partial amorphization of the irradiated surface of the material, while the structure of the non-irradiated surface did not change. In addition, the irradiated surface of the cerate endured solid-phase structural changes. Thus, upon high-energy ions irradiation in the range of Ne, Ar, Kr the cerate surface resembled the stages of spherulite formation - nucleation, growth (view of cauliflower), formation of spherulitic crust, respectively. The increase in water molecules release and reduction of molecular oxygen release from the barium cerate, irradiated by high-energy ions is found during vacuum constant rate heating. It is concluded that cerates undergo changes to the distances significantly exceeding the ion ranges in these materials. Features of high-energy ions influence on thermal desorption of carbon dioxide from cerates show, apparently, the formation of weakly bound carbonate compounds on the cerate surface in the irradiation process.

scholarly journals Population of American Cities: 1950-2009

2011 ◽  
Vol 16 (16) ◽  
pp. 153-172 ◽  
Author(s):  
Witold Wilczyński ◽  
Piotr Wilczyński
Keyword(s):  
Structural Changes ◽  
Social Problems ◽  
Population Change ◽  
The United States ◽  
Ethnic Composition ◽  
Continuous Growth ◽  
Historical Outline ◽  
Close Relationship ◽  
Contrasting View ◽  
American Cities

Population of American Cities: 1950-2009Contrary to the industrial epoch, cities have been interpreted in the last fifty years as the places facing the greatest economic and social problems. A contrasting view has emerged only recently that takes cities as sites of economic dynamism and social vitality. The paper offers evidence on population change for 118 greatest cities of the United States of America to assess how their fortunes have changed from the 1950s to 2009. Considerable diversity of experience was revealed and seven categories of cities have been distinguished as far as their population change patterns are concerned. These categories range from the continuous growth from 1950 until today to continuous decline. The most dynamic cities are located in the Sun Belt and they are relatively small and new.On the opposite, the biggest and old industrial centres of the Rust Belt have been losing inhabitants. In general, the pattern of population change shows close relationship with the economic situation and in particular, is connected with the structural changes in society and economy, namely the structural shifts toward more services-oriented economy, and smaller households.Essentially the paper offers the historical outline of the population changes in the biggest American urban centres. It should be seen as an introduction necessary for the more advanced studies concerning the issues of employment, incomes, ethnic composition, and various social problems which could explain the changing fortunes of particular cities.

In Situ High-Temperature Transmission Electron Microscopy Observations of the Formation of Nanocrystalline TiC from Nanocrystalline Anatase (TiO2)

1998 ◽  
Vol 4 (3) ◽  
pp. 269-277 ◽  
Author(s):  
A. Agrawal ◽  
J. Cizeron ◽  
V.L. Colvin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Solid Phase ◽  
Anatase Phase ◽  
High Resolution Electron Microscopy ◽  
Rutile Phase ◽  
Transmission Electron ◽  
New Phase

In this work, the high-temperature behavior of nanocrystalline TiO2 is studied using in situ transmission electron microscopy (TEM). These nanoparticles are made using wet chemical techniques that generate the anatase phase of TiO2 with average grain sizes of 6 nm. X-ray diffraction studies of nanophase TiO2 indicate the material undergoes a solid-solid phase transformation to the stable rutile phase between 600° and 900°C. This phase transition is not observed in the TEM samples, which remain anatase up to temperatures as high as 1000°C. Above 1000°C, nanoparticles become mobile on the amorphous carbon grid and by 1300°C, all anatase diffraction is lost and larger (50 nm) single crystals of a new phase are present. This new phase is identified as TiC both from high-resolution electron microscopy after heat treatment and electron diffraction collected during in situ heating experiments. Video images of the particle motion in situ show the nanoparticles diffusing and interacting with the underlying grid material as the reaction from TiO2 to TiC proceeds.

Analysis of Infrared Spectra of Fluid Films in Simulated EHD Contacts

1975 ◽  
Vol 97 (2) ◽  
pp. 145-150 ◽  
Author(s):  
J. L. Lauer ◽  
M. E. Peterkin
Keyword(s):  
Liquid Glass ◽  
Diamond Anvil Cell ◽  
Structural Changes ◽  
Spectroscopic Method ◽  
Emission Spectra ◽  
Phase Changes ◽  
Fluid Films ◽  
Diamond Anvil ◽  
Transition Points ◽  
Infrared Methods

Interferometry has provided the sensitivity needed for the gathering, through suitable windows, of infrared absorption and emission spectra of excellent resolution (<1 cm−1) from sample volumes even as small as EHD contact regions. Thus the power of molecular vibrational spectroscopy can be used to determine phase changes and structural changes in fluids subjected to conditions prevailing in EHD contacts. In this paper, some of the infrared methods are illustrated by the description of preliminary work in which the cavity of a high-pressure diamond anvil cell was used for contact simulation. Reference is made to a fluorescence-spectroscopic method of pressure determination in the diamond cell, which is also helpful in locating liquid/glass transition points.

Stimulation of Wells Damaged by Barite Present in Filter Cake or Scale

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Igor Ivanishin ◽  
Hisham A. Nasr-El-Din ◽  
Dmitriy Solnyshkin ◽  
Artem Klyubin
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Ethylenediaminetetraacetic Acid ◽  
Solid Phase ◽  
Barium Carbonate ◽  
Process Analysis ◽  
Drilling Fluid ◽  
Field Application ◽  
X Ray ◽  
Dissolution Efficiency

Summary High-temperature (HT) deep carbonate reservoirs are typically drilled using barite (BaSO4) as a weighting material. Primary production in these tight reservoirs comes from the network of natural fractures, which are damaged by the invasion of mud filtrate during drilling operations. For this study, weighting material and drilling fluid were sampled at the same drillsite. X-ray diffraction (XRD) and X-ray fluorescence analyses confirmed the complex composition of the weighting material: 43.2 ± 3.8 wt% of BaSO4 and 47.8 ± 3.3 wt% of calcite (CaCO3); quartz and illite comprised the rest. The drilling fluid was used to form the filter cake in a high-pressure/high-temperature (HP/HT) filter-press apparatus at a temperature of 300°F and differential pressure of 500 psig. Compared with the weighting material, the filter cake contained less CaCO3, but more nondissolvable minerals, including quartz, illite, and kaolinite. This difference in mineral composition makes the filter cake more difficult to remove. Dissolution of laboratory-grade BaSO4, the field sample of the weighting material, and drilling-fluid filter cake were studied at 300°F and 1,000 to 1,050 psig using an autoclave equipped with a magnetic stirrer drive. Two independent techniques were used to investigate the dissolution process: analysis of the withdrawn-fluid samples using inductively coupled plasma-optical emission spectroscopy, and XRD analysis of the solid material left after the tests. The dissolution efficiency of commercial K5-diethylenetriaminepentaacetic acid (DTPA), two K4-ethylenediaminetetraacetic acid (EDTA), Na4-EDTA solutions, and two “barite dissolvers” of unknown composition was compared. K5-DTPA and K4-EDTA have similar efficiency in dissolving BaSO4 as a laboratory-grade chemical and a component of the calcite-containing weighting material. No pronounced dissolution-selectivity effect (i.e., preferential dissolution of CaCO3) was noted during the 6-hour dissolution tests with both solutions. Reported for the first time is the precipitation of barium carbonate (BaCO3) when a mixture of BaSO4 and CaCO3 is dissolved in DTPA or EDTA solutions. BaCO3 composes up to 30 wt% of the solid phase at the end of the 6-hour reaction, and can be dissolved during the field operations by 5 wt% hydrochloric acid. Being cheaper, K4-EDTA is the preferable stimulation fluid. Dilution of this chelate increases its dissolution efficiency. Compared with commonly recommended solutions of 0.5 to 0.6 M, a more dilute solution is suggested here for field application. The polymer breaker and K4-EDTA solution are incompatible; therefore, the damage should be removed in two stages if the polymer breaker is used.

Sign in / Sign up

Export Citation Format

Share Document