scholarly journals Dipodal Tetraamide Derivatives of 1,10-Diaza-18-Crown-6 and Alkylmalonic Acids—Synthesis and Use as Ionophores in Ion Selective Membrane Electrodes

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4984
Author(s):  
Radosław Pomećko ◽  
Elżbieta Luboch ◽  
Maciej Jeszke
Keyword(s):  
Crown Ether ◽  
Magnesium Ion ◽  
Ion Selective Electrodes ◽  
Membrane Electrodes ◽  
Selectivity Coefficients ◽  
Lipophilic Anion ◽  
Selective Membrane ◽  
Conventional Electrode ◽  
The Relationship ◽  
Derivatives Of

Novel dipodal derivatives of an 18-membered diaza-crown ether with two diamide chains featuring methylmalonic or butylmalonic acid residues were obtained and tested as ionophores in ion-selective plasticized membrane electrodes. The objective of the study was to identify measurement conditions which ensure the most favorable performance for magnesium ion-selective electrodes. The relationship between the molar lipophilic anion salt-to-ionophore ratio and selectivity of electrodes was examined. The best result was obtained for the conventional electrode containing Mg2 ionophore. Calculated selectivity coefficients were as follows: logKMg/Ca = −2.77, logKMg/Na = −3.46 and logKMg.K = −2.24 (SSM, 1M).

Crown ether derivatives of anthraquinone as ionophores in ion-selective electrodes

1992 ◽  
Vol 4 (5) ◽  
pp. 533-537 ◽  
Author(s):  
John R. Allen ◽  
Tadeusz Cynkowski ◽  
Jayant Desai ◽  
Leonidas G. Bachas
Keyword(s):  
Crown Ether ◽  
Ion Selective Electrodes ◽  
Derivatives Of

Infrared spectra and substituent effects in 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones

1983 ◽  
Vol 48 (2) ◽  
pp. 586-595 ◽  
Author(s):  
Alexander Perjéssy ◽  
Pavol Hrnčiar ◽  
Ján Šraga
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Wave Number ◽  
Vibrational Coupling ◽  
Wave Numbers ◽  
Stretching Vibration ◽  
Stretching Vibrations ◽  
The Relationship ◽  
Derivatives Of ◽  
Effect Of Structure

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.

Private and Public Law

2020 ◽  
pp. 574-592
Author(s):  
Thomas W. Merrill
Keyword(s):  
Law And Economics ◽  
Public Law ◽  
Private Law ◽  
General Criterion ◽  
The Public ◽  
Private Ordering ◽  
Public Rights ◽  
Private And Public ◽  
The Relationship ◽  
Derivatives Of

This chapter explores the relationship between private and public law. In civil law countries, the public-private distinction serves as an organizing principle of the entire legal system. In common law jurisdictions, the distinction is at best an implicit design principle and is used primarily as an informal device for categorizing different fields of law. Even if not explicitly recognized as an organizing principle, however, it is plausible that private and public law perform distinct functions. Private law supplies the tools that make private ordering possible—the discretionary decisions that individuals make in structuring their lives. Public law is concerned with providing public goods—broadly defined—that cannot be adequately supplied by private ordering. In the twentieth and twenty-first centuries, various schools of thought derived from utilitarianism have assimilated both private and public rights to the same general criterion of aggregate welfare analysis. This has left judges with no clear conception of the distinction between private and public law. Another problematic feature of modern legal thought is a curious inversion in which scholars who focus on fields of private law have turned increasingly to law and economics, one of the derivatives of utilitarianism, whereas scholars who concern themselves with public law are increasingly drawn to new versions of natural rights thinking, in the form of universal human rights.

scholarly journals Ion-to-electron capacitance of single-walled carbon nanotube layers before and after ion-selective membrane deposition

2021 ◽  
Vol 188 (5) ◽  
Author(s):  
Elena Zdrachek ◽  
Eric Bakker
Keyword(s):  
Carbon Nanotube ◽  
Ion Selective Electrodes ◽  
Solid Contact ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Essential Step ◽  
Before And After ◽  
Selective Membrane ◽  
High Potential Stability ◽  
Potential Stability

AbstractThe capacitance of the ion-to-electron transducer layer helps to maintain a high potential stability of solid-contact ion-selective electrodes (SC-ISEs), and its estimation is therefore an essential step of SC-ISE characterization. The established chronopotentiometric protocol used to evaluate the capacitance of the single-walled carbon nanotube transducer layer was revised in order to obtain more reliable and better reproducible values and also to allow capacitance to be measured before membrane deposition for electrode manufacturing quality control purposes. The capacitance values measured with the revised method increased linearly with the number of deposited carbon nanotube–based transducer layers and were also found to correlate linearly before and after ion-selective membrane deposition, with correlation slopes close to 1 for nitrate-selective electrodes, to 0.7 and to 0.5 for potassium- and calcium-selective electrodes. Graphical abstract

scholarly journals Selective Membrane Sensor for Aluminum Determination in Food Products, Real Samples and Standard Alloys

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 504
Author(s):  
Sabry Khalil ◽  
Ashraf Y. Elnaggar
Keyword(s):  
Liquid Membrane ◽  
Food Products ◽  
Ion Selective Electrodes ◽  
Real Samples ◽  
Membrane Sensor ◽  
Aluminum Ion ◽  
Electrode Response ◽  
Aluminum Ions ◽  
Selective Membrane ◽  
Ph Range

The study involves the fabrication of an aluminum liquid membrane sensor based on the association of aluminum ions with the cited reagent 2,9-dimethyl-4,11-diphenyl -1,5,8,12-tetraaza cyclote tradeca-1,4,8,11-tetraene [DDTCT]. The characteristics slope (58 mV), rapid and linear response for aluminum ion was displayed by the proposed sensor within the concentration range 2.5 × 10−7–1.5 × 10−1 M, the detection limit (1.6 × 10−7) M, the selectivity behavior toward some metal cations, the response time 10 s), lifetime (150 days), the effect of pH on the suggested electrode potential and the requisite analytical validations were examined. The suitable pH range was (5.0–8.0 ), in this range the proposed electrode response is independent of pH. The suggested electrode was applied to detect the aluminum ions concentration in food products, real samples and standard alloys. The resulting data by the suggested electrode were statistically analyzed, and compared with the previously reported aluminum ion-selective electrodes in the literature.

On derivatives of fuzzy multi-dimensional mappings and applications under generalized differentiability

2021 ◽  
pp. 1-19
Author(s):  
M. Miri Karbasaki ◽  
M. R. Balooch Shahriari ◽  
O. Sedaghatfar
Keyword(s):  
Linear Function ◽  
Level Set ◽  
Fuzzy Numbers ◽  
Sufficient Condition ◽  
Continuous Linear ◽  
Generalized Differentiability ◽  
Relationship Of ◽  
The Relationship ◽  
Derivatives Of ◽  
Dimensional Mapping

This article identifies and presents the generalized difference (g-difference) of fuzzy numbers, Fréchet and Gâteaux generalized differentiability (g-differentiability) for fuzzy multi-dimensional mapping which consists of a new concept, fuzzy g-(continuous linear) function; Moreover, the relationship between Fréchet and Gâteaux g-differentiability is studied and shown. The concepts of directional and partial g-differentiability are further framed and the relationship of which will the aforementioned concepts are also explored. Furthermore, characterization is pointed out for Fréchet and Gâteaux g-differentiability; based on level-set and through differentiability of endpoints real-valued functions a characterization is also offered and explored for directional and partial g-differentiability. The sufficient condition for Fréchet and Gâteaux g-differentiability, directional and partial g-differentiability based on level-set and through employing level-wise gH-differentiability (LgH-differentiability) is expressed. Finally, to illustrate the ability and reliability of the aforementioned concepts we have solved some application examples.

scholarly journals Permutation Matrices, Their Discrete Derivatives and Extremal Properties

2020 ◽  
Vol 48 (4) ◽  
pp. 719-740
Author(s):  
Richard A. Brualdi ◽  
Geir Dahl
Keyword(s):  
Permutation Matrix ◽  
Permutation Matrices ◽  
Discrete Derivative ◽  
The Relationship ◽  
Derivatives Of ◽  
Extremal Properties

AbstractFor a permutation π, and the corresponding permutation matrix, we introduce the notion of discrete derivative, obtained by taking differences of successive entries in π. We characterize the possible derivatives of permutations, and consider questions for permutations with certain properties satisfied by the derivative. For instance, we consider permutations with distinct derivatives, and the relationship to so-called Costas arrays.

Sign in / Sign up

Export Citation Format

Share Document