A consideration of the impact of interactions with module effects on the direct measurement of subjective software attributes

Author(s):  
J. Moses
2021 ◽  
Author(s):  
Han Chen ◽  
Omar Abdelrahman

<p>A kinetic investigation of the vapor phase Hofmann elimination of tert-butylamine over H-ZSM-5 reveals a carbocation mediated E1-like mechanism, where isobutene and ammonia are exclusively produced over Brønsted acid sites. Hofmann elimination kinetics are found to be insensitive to Al content or siting, varying only with alkylamine carbocation stability (r<sub>tertiary</sub> > r<sub>secondary</sub> > r<sub>primary</sub>). Under conditions of complete tert-butylamine surface coverage, experimentally measurable apparent kinetics are directly equivalent to the intrinsic kinetics of the rate determining unimolecular surface elimination. The direct measurement of elementary step kinetics served as a water-free reactive probe, providing a direct measurement of the impact of water on solid Brønsted acid catalyzed chemistries at a microscopic level. Over a range of temperatures (453‒513 K) and tert-butylamine partial pressures (6.8×10<sup>-2</sup>‒6.8 kPa), water reversibly inhibits the rate of Hofmann elimination. Despite expected changes in aluminosilicate hydrophobicity, the water-induced inhibition is found to be insensitive to Al content, demonstrated to be due to one water molecule per Brønsted acid site. Regardless of the significant reduction in the rate of Hofmann elimination, kinetic interrogations and operando spectroscopic measurements reveal that the coverage of TBA adsorbed on H-ZSM-5 is unaltered in the presence of water. Cooperative adsorption between the tert-butylammonium surface reactant and water adsorbed on a neighboring framework oxygen is proposed to be responsible for the observed rate inhibition, the surface dynamics of which is quantitatively captured through kinetic modeling of experimental rate measurements.</p>


Lab on a Chip ◽  
2006 ◽  
Vol 6 (7) ◽  
pp. 914 ◽  
Author(s):  
Sergey S. Shevkoplyas ◽  
Tatsuro Yoshida ◽  
Sean C. Gifford ◽  
Mark W. Bitensky

2011 ◽  
Vol 2205 (1) ◽  
pp. 229-237 ◽  
Author(s):  
Lynne Cowe Falls ◽  
Linda Clary ◽  
A'arif Hamad ◽  
Ahmed Abdelfattah

2021 ◽  
Author(s):  
Han Chen ◽  
Omar Abdelrahman

<p>A kinetic investigation of the vapor phase Hofmann elimination of tert-butylamine over H-ZSM-5 reveals a carbocation mediated E1-like mechanism, where isobutene and ammonia are exclusively produced over Brønsted acid sites. Hofmann elimination kinetics are found to be insensitive to Al content or siting, varying only with alkylamine carbocation stability (r<sub>tertiary</sub> > r<sub>secondary</sub> > r<sub>primary</sub>). Under conditions of complete tert-butylamine surface coverage, experimentally measurable apparent kinetics are directly equivalent to the intrinsic kinetics of the rate determining unimolecular surface elimination. The direct measurement of elementary step kinetics served as a water-free reactive probe, providing a direct measurement of the impact of water on solid Brønsted acid catalyzed chemistries at a microscopic level. Over a range of temperatures (453‒513 K) and tert-butylamine partial pressures (6.8×10<sup>-2</sup>‒6.8 kPa), water reversibly inhibits the rate of Hofmann elimination. Despite expected changes in aluminosilicate hydrophobicity, the water-induced inhibition is found to be insensitive to Al content, demonstrated to be due to one water molecule per Brønsted acid site. Regardless of the significant reduction in the rate of Hofmann elimination, kinetic interrogations and operando spectroscopic measurements reveal that the coverage of TBA adsorbed on H-ZSM-5 is unaltered in the presence of water. Cooperative adsorption between the tert-butylammonium surface reactant and water adsorbed on a neighboring framework oxygen is proposed to be responsible for the observed rate inhibition, the surface dynamics of which is quantitatively captured through kinetic modeling of experimental rate measurements.</p>


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Emily M. Smith ◽  
Martin M. Stein ◽  
Cole Walsh ◽  
N. G. Holmes

Author(s):  
I. Poliakova

Introduction. Ukraine is among the leading mineral and raw material states. Nowadays in Ukraine prospected 20000 deposits and manifestations of 111 kinds of minerals (according to UNIAN - 200 minerals, 120 of which are used by mankind today). Of these 7807 deposits of 94 minerals with industrial value and accounted State balance of stocks. The greatest economic importance are coal, oil and gas, iron ore and manganese, native sulfur, rock and potassium salts, non-metallic building materials, mineral waters. These deposits are located in different geological regions of Ukraine. During the extraction of natural resources are exposure of personnel of mines and population from naturally occurring radioactive materials (NORM - nature occurring radioactive materials). Adequate levels of radiation safety and radiation protection of the population and the personnel of any branch determined, above all, of the relevant public, industry and other regulations and systems monitoring their implementation. One of the significant components of the increase of radiation safety are methodical application of appropriate radiation monitoring devices and obtaining reliable data (results), which will allow processing to estimate actual radiation situation at the facility. The natural and climatic conditions of the mines are specific. This fact is confirmed by the level of humidity, which can reach the value of 99%, but the temperature and atmospheric pressure are unchanged. In the process of work in the mine there is a harmful factor for the human body - dust in the air of the working zone and radioactivity. Alpha particles formed as a result of the decomposition of the daughter products of the decay of 224Ra, 223Ra and 226Ra, settling on aerosols and  enter the human body by inhalation, as well as actinon, radon and thoron lead to an increase in the dose of personnel. Purpose. The purpose of the study is to determine the radiation situation at the sites for the extraction of minerals, taking into account the factors that affect the reliability of the results. Establishing reliable quantitative characteristics of harmful factors of the environment, which negatively affects the body of the personnel. Conducting an analysis of existing methods of measuring by direct methods and making suggestions for their improvement under the influence of factors that contribute to obtaining results with an error of more than 75%. Methods. In the course of the research, direct measurement methods, calculations and analytical research were used to achieve the set goal and to solve the set tasks. During experimental and analytical work of physico-chemical and radiometric measurement methods were used, certified equipment and measuring control devices were used.  Results. Measurements of equilibrium volume activity of radon and thoron using direct method is necessary task to assess the impact on personnel at the work time. Quantitative assessment the air gases such as 222Rn, 220Rn, 219Rn depends on the amount of deposits of the uranium and thorium series in the earth's surface. It should not be forgotten that after the radioactive decay of the aforementioned gases, a significant amount of α-radioactive daughter nuclides that enter the miners' body is formed. This causes an increase in the dose from the accumulation of α-radionuclides in the miners' organism, but this staff is not officially considered which works with NORM (with the exception of only uranium miners). Comparing the results obtained by measuring 222Rn and 220Rn provided in Tables 1 and 2 using direct measurement methods using RHA-2006 «ICAR» and AlphaGuard PQ2000, show difference in the results, especially at higher humidity and with increasing of numbers of mineral dust in the air of mines. Conclusions. The conclusions obtained by the author of the article on the state of experimental research and analysis of data: Climatic conditions play an important role in data reliability. It is necessary to carefully select the devices of radiation control and measurement methods. Conduct a quantitative analysis of radionuclides and set a dose for miners only from radon and thoron, which is possible with the use of a-spectrometry. In this study, an express control (real-time control) of α-emitting radionuclides in the air was carried out using detectors, whose activities are based on the use of an ionization chamber. But as a result of this study, we obtain the total activity of α-radionuclides in the air and α-aerosols identified with a significant systematic error. Since the measuring capabilities of these devices are determined by the humidity of no more than 85%. The creation of new normative documents to determine the impact on employees and the population of the NORM should be a consequence and an integral part of scientific research in this field. The authenticity of experimental methods and the reliability of the results are the basis upon which radiation safety will be based on working with natural radionuclides.


2014 ◽  
Vol 977 ◽  
pp. 141-145
Author(s):  
Kuo Hsiang Tang ◽  
Hong Ling He

Currently, there are three major methods for infrared carbon-sulfur analyzer to measure blank values. This paper discusses the advantages and disadvantages of the three methods by using the measured test data from specific tests, and finally makes a conclusion that, the Cycle Measurement of Sulfur Blank Value (CMSBV) created by JIANHUAN WEI is the most effective method. Entering this sulfur blank value into analyser, the automatic deduction of blank values will be performed. As a result, the impact of the blank value on sulfur measurement can be eliminated. Key words: Sulfur blank value, direct measurement method, indirect measurement method, The Cycle Measurement of Sulfur Blank Value (CMSBV)


1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.


1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.


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