Rigorous determination of the stability of linear n-node circuits from network determinants and the appropriate role of the stability factor K of their reduced two-ports

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

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Spectrophotometric indicators of the stability of anthocyanin-containing extracts depending on the color of plant materials

Ovidius University Annals of Chemistry ◽

10.2478/auoc-2020-0016 ◽

2020 ◽

Vol 31 (2) ◽

pp. 88-92

Author(s):

Vladimir Mikhailovich Koldaev ◽

Artem Yurevich Manyakhin ◽

Petr Semenovich Zorikov

Keyword(s):

Hydrochloric Acid ◽

Stability Factor ◽

Plant Materials ◽

Herbal Preparations ◽

Violet Color ◽

The Stability ◽

Selection Of ◽

Factor Coefficient ◽

Anthocyanin Degradation

AbstractThis paper aims at spectrophotometric determination of changes in stability of extractable anthocyanins during drying of plant materials depending on their color. Raw and dried colored parts of 50 plant species from 25 families were used for the study. The extracts were prepared over 95% ethanol acidified with hydrochloric acid (pH ~ 1). The absorption spectra were registered within the range of 210 to 680 nm. The extinction variability factor, coefficient of intensity absorption relative and generalized stability factor were used to determine the anthocyanin degradation. The highest values of the stability factor were obtained for the extracts from fruit shells of burgundy or violet color within the range of 0.934±0.024 to 0.973±0.024, while the extracts from flower petals of the same care featured the stability factor that was 1.19 to 1.44 times less. The values of the stability factor of the extracts from black, red and blue materials are 1.15 to 1.19 times, 1.74 to 2.48 times and 4.65 to 4.84 times less respectively than those of the extracts from violet-burgundy materials. It is appropriate to apply the spectrophotometric factors of anthocyanins stability used in this study to selection of promising plants for industrial cultivation as material of anthocyanin-containing herbal preparations. The most stable anthocyanins are those of burgundy-purple and black fruits.

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Avaliação da estabilidade de agregados e a vulnerabilidade à erosão ao longo de uma vertente no município de Araruna, região noroeste do Paraná-Brasil / Evaluation of aggregates stability and vulnerability to erosion along a shed in the municipality of Araruna, northwest region of Paraná-Brazil

Caderno de Geografia ◽

10.5752/p.2318-2962.2018v28n55p845-862 ◽

2018 ◽

Vol 28 (55) ◽

pp. 845-862

Author(s):

Fabiana Barros Medeiros ◽

Francieli Sant'ana Marcatto ◽

Hélio Silveira ◽

MariaTeresa De Nóbrega

Keyword(s):

Structural Analysis ◽

Soil Cover ◽

Morphological Characteristics ◽

Soil Horizons ◽

Water Flows ◽

Sandstone Formation ◽

The Stability ◽

Northwest Region

Esta pesquisa tem como objetivo estudar a vulnerabilidade à erosão dos solos da zona de contato do arenito da Formação Caiuá com o basalto da Formação Serra Geral, no município de Araruna, Mesorregião Noroeste Paranaense, dando enfoque ao papel da estabilidade da estrutura atual dos solos, considerando-se as alterações produzidas pelas formas de uso e ocupação da área. A análise realizada também considerou as variações das características morfológicas dos solos em perfil e ao longo da litossequência (sistema pedológico), assim como os seus reflexos na geração de setores mais ou menos suscetíveis à erosão na vertente. Para o levantamento dos solos ao longo da vertente foram utilizados os procediments propostos pela Análise Estrutural da Cobertura Pedológica e a coleta de amostras para a determinação da granulometria e estabilidade de agregados. Os resultados indicaram a ação dos fluxos de água laterais e verticais, atuando na transformação dos horizontes dos solos ao longo da vertente e uma variação da estabilidade estrutural associada as características morfológicas dos solos e ao tipo de uso e manejo empregado. Os Argissolos apresentaram agregados pequenos e um gradiente textural entre o horizonte superficial e subsuperficial, lhe conferindo uma forte suscetibilidade a erosão. O Nitossolo não apresentou grande diferenciação no tamanho dos agregados, exceto no horizonte Bw, onde a redução no tamanho dos agregados se associaram a mudança morfológica da estrutura do solo.AbstractThis research aims to study the vulnerability to soil erosion of the contact zone of the sandstone Formation Caiuá with basalt of the Serra Geral Formation, in the municipality of Araruna, Paraná Northwest Region, giving focus to the role of the stability of the current structure of soils, considering the changes produced by the forms of use and occupation of the area. The analysis also considered variations of morphological characteristics of soils in profile and along the lithosactivity (pedological system), as well as your reflexes in the generation of sectors more or less susceptible to erosion in the shed. For the survey of the soils along the strand, the procedures proposed by the Structural Analysis of the Pedological Coverage and the collection of samples for the determination of the granulometry and stability of aggregates were used. The results indicated the action of the lateral and vertical water flows, acting on the transformation of the soil horizons along the slope and a variation of the structural stability associated with the morphological characteristics of the soils and the type of use and management used. The Argisols presented small aggregates and a textural gradient between the surface and subsurface horizon, giving it a strong susceptibility to erosion. The Nitossolo did not show great differentiation in the size of the aggregates, except in the Bw horizon, where the reduction in the size of the aggregates was associated to the morphological change of the soil structure.Keywords: structural analysis of the soil cover, stability of aggregates, susceptibility to erosion, pedological systems.

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The contribution of methionine to the stability of the Escherichia coli MetNIQ ABC transporter-substrate binding protein complex

Biological Chemistry ◽

10.1515/hsz-2015-0131 ◽

2015 ◽

Vol 396 (9-10) ◽

pp. 1127-1134 ◽

Cited By ~ 8

Author(s):

Phong T. Nguyen ◽

Qi Wen Li ◽

Neena S. Kadaba ◽

Jeffrey Y. Lai ◽

Janet G. Yang ◽

...

Keyword(s):

Escherichia Coli ◽

Complex Formation ◽

Dissociation Constant ◽

Binding Protein ◽

Crystallographic Analysis ◽

E Coli ◽

Multiple Conformations ◽

The Stability

Abstract Despite the ubiquitous role of ATP-binding cassette (ABC) importers in nutrient uptake, only the Escherichia coli maltose and vitamin B12 ABC transporters have been structurally characterized in multiple conformations relevant to the alternating access transport mechanism. To complement our previous structure determination of the E. coli MetNI methionine importer in the inward facing conformation (Kadaba et al. (2008) Science 321, 250–253), we have explored conditions stabilizing the outward facing conformation. Using two variants, the Walker B E166Q mutation with ATP+EDTA to stabilize MetNI in the ATP-bound conformation and the N229A variant of the binding protein MetQ, shown in this work to disrupt methionine binding, a high affinity MetNIQ complex was formed with a dissociation constant measured to be 27 nm. Using wild type MetQ containing a co-purified methionine (for which the crystal structure is reported at 1.6 Å resolution), the dissociation constant for complex formation with MetNI is measured to be ∼40-fold weaker, indicating that complex formation lowers the affinity of MetQ for methionine by this amount. Preparation of a stable MetNIQ complex is an essential step towards the crystallographic analysis of the outward facing conformation, a key intermediate in the uptake of methionine by this transport system.

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MICRO DETERMINATION OF DOPAMINE IN BIOLOGICAL SAMPLES BY COUPLING REACTION

Journal of Engineering Studies and Research ◽

10.29081/jesr.v22i4.250 ◽

2018 ◽

Vol 22 (4) ◽

Author(s):

AHMED JASSIM MUKLIVE AL-OGAIDI

Keyword(s):

Mole Fraction ◽

Biological Samples ◽

Azo Dye ◽

Coupling Reaction ◽

Stability Factor ◽

Relative Standard ◽

The Stability ◽

Fraction Method ◽

Orange Color

The paper presents the development of an analytical method to determine dopamine by coupling reaction with diazotized solution of 4-Aminoantipyrine in basic media to give a compound with a single azo dye salt having orange color soluble in water. A calibration curve for a range of concentration (9.14x10-5 – 2.28x10-3 μg.mL-1) was realized and the value of molar absortivity was 1.5x103 L.mol-1.cm-1, with a relative standard deviation more than 1.26% and a recovery 98.77%. As we study the nature of the azo dye by mole fraction method, from the practical value we found that the mole fraction of the dye compound is 1:1 (dopamine: 4- amino antipyrine) and the stability factor reach to 1.4x106 L.mol-1. The described procedure is very simple, low-time-consuming, provides high throughput of examined samples, and could be used for routine screening and confirmatory analyses as well. The method was successfully validated to the analysis of the dopamine in biological samples.

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Exploring the Role of L10 Loop in New Delhi Metallo-β-lactamase (NDM-1): Kinetic and Dynamic Studies

Molecules ◽

10.3390/molecules26185489 ◽

2021 ◽

Vol 26 (18) ◽

pp. 5489

Author(s):

Alessandra Piccirilli ◽

Emanuele Criscuolo ◽

Fabrizia Brisdelli ◽

Paola Sandra Mercuri ◽

Sabrina Cherubini ◽

...

Keyword(s):

Enzyme Activity ◽

Amino Acid ◽

Double Mutant ◽

Amino Acid Substitutions ◽

New Delhi ◽

Kinetic Behavior ◽

Dynamic Studies ◽

The Stability

Four NDM-1 mutants (L218T, L221T, L269H and L221T/Y229W) were generated in order to investigate the role of leucines positioned in L10 loop. A detailed kinetic analysis stated that these amino acid substitutions modified the hydrolytic profile of NDM-1 against some β-lactams. Significant reduction of kcat values of L218T and L221T for carbapenems, cefazolin, cefoxitin and cefepime was observed. The stability of the NDM-1 and its mutants was explored by thermofluor assay in real-time PCR. The determination of TmB and TmD demonstrated that NDM-1 and L218T were the most stable enzymes. Molecular dynamic studies were performed to justify the differences observed in the kinetic behavior of the mutants. In particular, L218T fluctuated more than NDM-1 in L10, whereas L221T would seem to cause a drift between residues 75 and 125. L221T/Y229W double mutant exhibited a decrease in the flexibility with respect to L221T, explaining enzyme activity improvement towards some β-lactams. Distances between Zn1-Zn2 and Zn1-OH- or Zn2-OH- remained unaffected in all systems analysed. Significant changes were found between Zn1/Zn2 and first sphere coordination residues.

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MICRO DETERMINATION OF DOPAMINE IN BIOLOGICAL SAMPLES BY COUPLING REACTION

Journal of Engineering Studies and Research ◽

10.29081/jesr.v22i4.92 ◽

2016 ◽

Vol 22 (4) ◽

pp. 7-12

Author(s):

AHMED JASSIM MUKLIVE AL-OGAIDI

Keyword(s):

Mole Fraction ◽

Biological Samples ◽

Azo Dye ◽

Coupling Reaction ◽

Stability Factor ◽

Relative Standard ◽

The Stability ◽

Fraction Method ◽

Orange Color

The paper presents the development of an analytical method to determine dopamine by coupling reaction with diazotized solution of 4-Aminoantipyrine in basic media to give a compound with a single azo dye salt having orange color soluble in water. A calibration curve for a range of concentration (9.14x10-5 – 2.28x10-3 μg.mL-1) was realized and the value of molar absortivity was 1.5x103 L.mol-1.cm-1, with a relative standard deviation more than 1.26% and a recovery 98.77%. As we study the nature of the azo dye by mole fraction method, from the practical value we found that the mole fraction of the dye compound is 1:1 (dopamine: 4- amino antipyrine) and the stability factor reach to 1.4x106 L.mol-1. The described procedure is very simple, low-time-consuming, provides high throughput of examined samples, and could be used for routine screening and confirmatory analyses as well. The method was successfully validated to the analysis of the dopamine in biological samples.

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The Degree Of Ambiguity Of Homonymous Syntactic Structures In The Bosnian Language

Slavica Lodziensia ◽

10.18778/2544-1795.01.11 ◽

2017 ◽

Vol 1 ◽

pp. 127-136

Author(s):

Jasmin Hodžić

Keyword(s):

Native Speakers ◽

Syntactic Ambiguity ◽

Syntactic Structures ◽

The Stability

In this paper has been specifi cally considered the issue of the potential and the actual syntactic ambiguity (or syntactic homonymy) which has led to the results indicating that the existence of ambiguity in syntax is not negligible, and that the role of the context in the analysis of the syntactic ambiguity is not as it has been assumed. A selected number of examples have been presented to native speakers in order to assess the meaning. The results of this questionnaire show that the native speakers have confi rmed the ambiguity of all the sentences. Ambiguity has been additionally analyzed through the calculation of the degree of ambiguity (i.e., determination of the stability of meaning) and the index of the degree of ambiguity (i.e., determination of the consistency of meaning).

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IMPORT SUBSTITUTION: THE BOARDERS OF THE ENERGY SECURITY

MGIMO Review of International Relations ◽

10.24833/2071-8160-2016-1-46-180-187 ◽

2016 ◽

pp. 180-187

Author(s):

N. N. Shvets

Keyword(s):

Import Substitution ◽

Developed Countries ◽

High Tech ◽

Interstate Cooperation ◽

Electric Equipment ◽

National Production ◽

The Stability ◽

Globalized World

The article analyzes issues of import substitution in national production and determination of its effective scale considering the country's involvement to international division of labor and an important role of interstate cooperation in today's globalized world. The relevance of the study relies on the fact, that unfavorable global economic and politic situation in 2014-2015 raised concerns among the Russian authorities and the society in general about the stability of the economy and the necessity to increase its independence and self-sustainability. Sectoral economic sanctions imposed by western developed countries could potentially lead to disruptions in the supply of components and equipment that ensure the operation of power facilities. Currently power companies are influenced by the external economic situation and the devaluation of the national currency. As the result, goods of foreign manufacture have become significantly more expensive and opportunities for power companies to realize their investing and repair programs have been reduced. Thereby there is a high importance of developing the substitution-oriented production of the high-tech electric equipment within the Russian Federation's territory. Import substitution issues are closely related to the governmental industrial policy. The programs of the national production development need huge investments and that's why issues of economic effectiveness evaluation are highly relevant. But balances between economy's specialization and diversification, import substitution and export orientation are also highly important. Such measures directed at artificial import rationing as sanctions against foreign goods, creating favorable competitive environment for national producers, governmental grants could in prospect lead to a stagnation of the economy.

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Regulation of phenobarbital-inducible cytochrome P-450s in rat and mouse liver following dexamethasone administration and hypophysectomy

Biochemical Journal ◽

10.1042/bj2540789 ◽

1988 ◽

Vol 254 (3) ◽

pp. 789-797 ◽

Cited By ~ 55

Author(s):

R R Meehan ◽

L M Forrester ◽

K Stevenson ◽

N D Hastie ◽

A Buchmann ◽

...

Keyword(s):

Species Difference ◽

Potent Inducer ◽

The Difference ◽

The Stability ◽

And Function ◽

Synthetic Glucocorticoids ◽

Cytochrome P 450 ◽

Hepatic Cytochrome

Cytochrome P-450s are a superfamily of haem-containing proteins involved in the metabolism of foreign compounds, as well as a variety of endogenous molecules. The hepatic levels and function of this diverse group of enzymes are determined by both constitutive and xenobiotic regulators. To examine the role of constitutive factors in cytochrome P-450 regulation, the levels of three distinct groups of phenobarbital-inducible hepatic cytochrome P-450s were studied following dexamethasone-treatment or hypophysectomy. In the mouse, dexamethasone was a potent inducer of proteins within the PB1 (subfamily IIC), PB2c (family III) and PB3 (subfamily IIB) families. These findings were strikingly different from the effects in the rat where essentially no effect on PB3 expression and indeed suppression of proteins related to PB1 was observed. Determination of mRNA concentration indicated that the difference was at the level of transcription. These findings indicate that synthetic glucocorticoids have the potential to be potent phenobarbital-like inducing agents. In the mouse hypophysectomy, like dexamethasone, induced hepatic mRNA of P-450 from families P-450IIB, P-450IIC and P-450III. Again a species difference was observed as this treatment had essentially no effect in the rat. These data in the mouse indicate that factors produced in the pituitary can either affect the transcription rate of phenobarbital and dexamethasone-inducible P-450 genes or influence the stability of their mRNAs.

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