An improved correlation for reliable assessment of the detonation performance of non‐ideal explosives containing metals and the other solid particulates

2020 ◽  
Author(s):  
Mohammad Keshavarz ◽  
Mohammad Jafari ◽  
Mohammad Reza Motamedi ◽  
Seyyed Hesamodin Hosseini
Keyword(s):  
The Other ◽  
Detonation Performance ◽  
Reliable Assessment ◽  
Solid Particulates

scholarly journals Assessment of the Permeability to Aggressive Agents of Concrete with Recycled Cement and Mixed Recycled Aggregate

2021 ◽  
Vol 11 (9) ◽  
pp. 3856
Author(s):  
Blas Cantero ◽  
Miguel Bravo ◽  
Jorge de Brito ◽  
Isabel Fuencisla Sáez del Bosque ◽  
César Medina
Keyword(s):  
Construction Industry ◽  
Recycled Concrete ◽  
The Other ◽  
Recycled Aggregate ◽  
Transport Mechanisms ◽  
High Quality ◽  
Conventional Concrete ◽  
Reliable Assessment ◽  
Alternative Material ◽  
Carbon Dioxide Co2

Acceptance by the construction industry of recycled concrete as a sustainable alternative material is contingent upon a reliable assessment of its permeability to corrosive agents. This study analyses the transport mechanisms associated with chloride (Cl−), oxygen (O2) and carbon dioxide (CO2) ions in concrete with cement made with 10% or 25% ground recycled concrete (GRC) separately or in combination with 50% mixed recycled aggregate (MRA). The findings show that, irrespective of aggregate type, concrete with GRC exhibited lower resistance to ingress than conventional concrete due to its greater porosity. Nonetheless, O2 permeability was consistently below 4.5 × 10−17 m2 and CO2 penetration, under 4 mm/year0.5, indicative of concrete with high quality. Resistance to CO2 and Cl− penetration in the materials with 10% GRC was similar to the values observed in conventional concrete. On the other hand, the incorporation of 25% GRC increased the penetration of CO2 and Cl- by 106% and 38%, respectively. Further to those findings in normal carbonation environments, reinforcement passivity would be guaranteed in such recycled materials over a 100 year service life.

scholarly journals Chromium in Anthropogenically Polluted and Naturally Enriched Soils: A Review

2018 ◽  
Vol 49 (4) ◽  
pp. 297-312
Author(s):  
J. Jeřábková ◽  
V. Tejnecký ◽  
L. Borůvka ◽  
O. Drábek
Keyword(s):  
Complex System ◽  
Contaminated Soils ◽  
Industrial Pollution ◽  
The Other ◽  
Ultramafic Rocks ◽  
Soil Environment ◽  
Potential Toxicity ◽  
Reliable Assessment ◽  
Living Organisms ◽  
Harmful Effects

Abstract Chromium (Cr) is a very important element examined for last decades on many expert fields. Its toxicity, mobility and bio-availability are strongly dependent on its oxidation state, Cr(III) and Cr(VI). Hexavalent form Cr(VI) is a known carcinogen with many harmful effects on living organisms, on the other hand trivalent Cr(III) form is an important micronutrient necessary for lipid metabolism. Contamination of the environment by Cr may come from anthropogenic industrial pollution or from naturally enriched sites, especially ultramafic rocks and their derived soils. Environmental conditions of soils and water represent a very complex system, which makes reliable assessment of its fate and potential toxicity and transport a really difficult task. A number of studies have been performed to describe Cr behaviour in these systems, as well as to optimize its determination, especially speciation methods. The main objective of this contribution is to summarize and present the today’s knowledge about the occurrence, speciation, and behaviour of Cr in soil environment, with a specific emphasis to description of differences between naturally enriched and anthropogenically contaminated soils.

scholarly journals Validation of Analytical Procedures: Graphic and Calculated Criteria for Assessment of Methods Linearity in Practice

2019 ◽  
Vol 8 (2) ◽  
pp. 122-130 ◽  
Author(s):  
N. A. Epshtein
Keyword(s):  
Experimental Data ◽  
Linear Dependence ◽  
The Other ◽  
Mathematical Statistics ◽  
Formal Approach ◽  
Small Deviations ◽  
Other Hand ◽  
Reliable Assessment ◽  
Analytical Procedures ◽  
Measured Response

Introduction. «Linearity» is one of the required characteristics when validating analytical procedures. The issues of the validation of linearity procedures are still relevant.Aim. To consider the main graphical and calculated criteria for confirmation of the linearity of analytical procedures and their restrictions, as well as to give recommendations.Materials and methods. Statistical calculations were performed using MS Excel. Experimental data were obtained by HPLC.Results and discussion. The main criteria for proving/confirming the linearity of analytical procedures and their restrictions are considered in detail. It is shown that these criteria cannot always give a reliable assessment of the linearity of the procedure, the possible reasons for this are indicated and recommendations are given.Conclusion. When validating the procedures, it is necessary to prove/confirm their linearity by using two, and, more reliably, three criteria, one of which must be the linearity of the plot of measured response (Y) vs concentration of the tested substance (C). On the other hand, we demonstrate here that a formal approach should not be used for the estimation of non-linearity of the procedure when using graphical and calculation criteria based on mathematical statistics, since they do not take into account the possibility of practical insignificance of small deviations from the linear dependence of Yon C.

Stromatoporoids from the Famennian (Devonian) Wabamun Formation, Normandville oilfield, north–central Alberta, Canada

1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn
Keyword(s):  
Patch Reef ◽  
Abundant Species ◽  
The Other ◽  
North Central ◽  
Biotic Crisis

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

D. The Line Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 207-244
Author(s):  
R. P. Kraft
Keyword(s):  
Variable Stars ◽  
The Other ◽  
Line Spectrum ◽  
Afternoon Session ◽  
Empirical Information ◽  
Pulsating Variable Stars ◽  
Almost Continuous ◽  
Informal Approach

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

Observing programme for the 24-inch/36-inch Schmidt telescope

1966 ◽  
Vol 24 ◽  
pp. 337
Author(s):  
W. Iwanowska
Keyword(s):  
The Other ◽  
Schmidt Telescope ◽  
Flint Glass

A new 24-inch/36-inch//3 Schmidt telescope, made by C. Zeiss, Jena, has been installed since 30 August 1962, at the N. Copernicus University Observatory in Toruń. It is equipped with two objective prisms, used separately, one of crown the other of flint glass, each of 5° refracting angle, giving dispersions of 560Å/mm and 250Å/ mm respectively.

A hard choice for Tomasello

2020 ◽  
Vol 43 ◽  
Author(s):  
Philip Pettit
Keyword(s):  
Joint Action ◽  
The Other ◽  
Hard Choice ◽  
Margaret Gilbert ◽  
Michael Bratman ◽  
Human Sense ◽  
Sense Of Obligation

Abstract Michael Tomasello explains the human sense of obligation by the role it plays in negotiating practices of acting jointly and the commitments they underwrite. He draws in his work on two models of joint action, one from Michael Bratman, the other from Margaret Gilbert. But Bratman's makes the explanation too difficult to succeed, and Gilbert's makes it too easy.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

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