scholarly journals Voltammetry application for quantitative definition of L-Thyroxine

2011 ◽  
Vol 10 (5) ◽  
pp. 140-144
Author(s):  
S. V. Dome ◽  
Ye. A. Ivanovskaya
Keyword(s):  
Quantitative Determination ◽  
Background Electrolyte ◽  
Model Solution ◽  
Accumulation Time ◽  
Time Scanning ◽  
Voltammetric Behavior ◽  
Definition Of ◽  
Object Of Study ◽  
Quantitative Definition

The technique of quantitative determination of L-thyroxin in a model solution and an individual preparation with the aid of inversion voltammetry is developed. For this purpose, it is necessary to study working conditions of the voltammetric behavior of L-thyroxin, namely, to estimate the influence of different factors (accumulation potential, accumulation time, scanning rate, nature of background electrolyte) on the potential and current of thyroxin recovery. The object of study is L-thyroxin (Sigma, USA). As a result, working characteristics of quantitative determination of L thyroxin in a model solution and monopreparation are determined.

Assessment of NOA risk for the excavation of a highway tunnel system ("Gronda di Genova", Italy): from NOA-oriented geological model to asbestos quantification

2020 ◽  
Author(s):  
Fabrizio Piana ◽  
Chiara Avataneo ◽  
Luca Barale ◽  
Serena Botta ◽  
Roberto Compagnoni ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Geological Model ◽  
Representative Sampling ◽  
Highway Tunnel ◽  
Tunnel Section ◽  
Risk Zonation ◽  
Minimum Number ◽  
Definition Of ◽  
Tunnel System

<p>For a reliable evaluation of the geo-environmental risk related to the presence of naturally occurring asbestos (NOA) in rocks excavated for large infrastructural projects, a proper procedure has to be followed in order to achieve:</p><p>1) the definition of a detailed geological model, tailored on NOA-related issues;</p><p>2) a representative sampling;</p><p>3) a reliable quantitative determination of asbestos content in rock samples.</p><p>Here we describe the approach followed for the evaluation of the NOA content for the excavation of a complex highway tunnel system (“Gronda di Genova” NW Italy), in NOA-bearing meta-ophiolite rocks. The NOA-oriented geological model has been constrained by the individuation of the main “NOA-related petrofacies” —i.e., classes of rocks with common lithological, structural and NOA content features—, and by the identification of “homogeneous zones” – i.e. geological units into which the NOA petrofacies are distributed. Implementation of Gy’s theory on sampling was used and here described to maintain statistical validity during sample processing from the primary rock sample to the analytical sample. SEM-EDS procedure for the quantitative determination of NOA content was improved with an error analysis delivering the minimum number of fibers to be measured to achieve the best analytical results.</p><p>The obtained results allowed the prediction of the NOA hazard in terms of risk zonation along the tunnel section and for the evaluation of the amount of asbestos-bearing spoil to be excavated and managed.</p>

scholarly journals Validation of the HPLC-UV Method for Quantitative Determination of Steroid Sapogenin Diosgenin from Hay Fenugreek Seeds, Trigonella Foenum-graecum L.

2020 ◽  
Vol 9 (4) ◽  
pp. 107-114
Author(s):  
A. E. Sukhanov ◽  
A. N. Stavrianidi ◽  
E. D. Kubasova ◽  
A. S. Panasyuk ◽  
O. V. Buyuklinskaya
Keyword(s):  
Medicinal Plant ◽  
Quantitative Determination ◽  
Plant Extracts ◽  
Raw Materials ◽  
Biologically Active ◽  
Fenugreek Seeds ◽  
Plant Raw Materials ◽  
Object Of Study ◽  
Trigonella Foenum Graecum L

Introduction. Modern pharmacognostic research is aimed at searching for plant biologically active individual compounds (hereinafter referred to as RBAIS) isolated from plant extracts.Aim. Validation of HPLC-UV quantitative determination of sapogenin diosgenin in plant extracts from fenugreek seeds.Materials and methods. The object of study was raw materials-fenugreek seeds produced as medicinal plant raw materials by LLC «Sage» (Irkutsk). Validation of the method was carried out according to the parameters: specificity, linearity, correctness, precision in accordance with the requirements of SP XIV. One series of medicinal plant raw materials was used for the analysis, such as serial number – 010117, release date – 15 february 2017.Results and discussion. Validation characteristics were determined and their compliance with the necessary acceptance criteria was experimentally confirmed.Conclusion. It is established that the developed method of identification and quantitative determination of diosgenin in fenugreek seed extracts by HPLC-UV is correct, precise, specific and linear in the analytical field.

scholarly journals Improvement of the scheme analysis of the component composition of a larch wood

2020 ◽  
Author(s):  
Э.И. Евстигнеев
Keyword(s):  
Component Composition ◽  
Water Soluble ◽  
Special Equipment ◽  
Component Structure ◽  
Wood Component ◽  
Extractive Substances ◽  
Definition Of ◽  
Quantitative Definition ◽  
Scheme Analysis

Разработана схема анализа компонентного состава лиственницы, предусматривающая определение таких компонентов, как полисахариды, целлюлоза, нецеллюлозные полисахариды, лигнин, экстрактивные вещества и зола. В отличие от известных схем анализа химического состава древесины, она содержит новую стадию, а именно определение общего содержания полисахаридов фотоколориметрическим методом. Обычно для этой цели используют определение холоцеллюлозы, однако известные методы не позволяют выделить все полисахариды, поскольку в процессе выделения часть из них неизбежно утрачивается. Зная общее содержание полисахаридов, можно определить содержание нецеллюлозных полисахаридов. Такой подход имеет явное преимущество, по сравнению с традиционно используемым определением отдельно гемицеллюлоз и отдельно водорастворимых полисахаридов, так как в этом случае происходит потеря части полисахаридов. Предложенная схема дает возможность достаточно полно охарактеризовать компонентный состав древесины лиственницы, не прибегая к использованию специального оборудования. Разработанный метод определения арабиногалактана обладает высокой селективностью к определяемому компоненту древесины в присутствии большого количества примесей, в связи с чем он может быть рекомендован для количественного определения арабиногалактана как в водных растворах, так и в древесине. The scheme of the analysis of component structure of a larch providing determination of such components as polysaccharides, cellulose, not cellulose polysaccharides, lignin, extractive substances and ashes is developed. Unlike the known schemes of the analysis of the chemical composition of wood, it contains a new stage, namely determination of the general content of polysaccharides by a photocolorimetric method. Usually, for this purpose use definition of a holocellulose, however the known methods do not allow to emit all polysaccharides as in the course of allocation part of them is inevitably lost. Knowing the general content of polysaccharides, it is possible to determine the content of not cellulose polysaccharides. Such approach has clear advantage in comparison with traditionally used determination separately of hemicelluloses and separately water-soluble polysaccharides since in this case there is a loss of a part of polysaccharides. The scheme offered in work, gives the chance rather fully to characterize component composition of wood of a larch, without resorting to use of the special equipment. The developed method of an arabinogalactan determination has high selectivity to the defined wood component in the presence of a large amount of impurity in this connection it can be recommended for quantitative definition of an arabinogalactan both in water solutions, and in wood.

DEVELOPMENT OF THE COMPOSITION AND STANDARTIZATION OF THE COLLECTION FOR THE PREVENTION OF INFLAMMATORY PERIODONTAL DISEASES

2021 ◽  
pp. 73-79
Author(s):  
Groznov A.A. ◽  
Kachulin V.A. ◽  
Nesterova O.V.
Keyword(s):  
Essential Oil ◽  
Medicinal Plant ◽  
Quantitative Determination ◽  
Periodontal Diseases ◽  
Antimicrobial Effect ◽  
Biologically Active ◽  
Extractive Substances ◽  
Definition Of ◽  
Active Substances

Taking into account the literature data, as well as the research conducted by the authors, the composition of the collection for the prevention of inflammatory periodontal diseases has been developed, which includes medicinal plant raw materials:medicinal pimenta fruits, medicinal sage leaves, yarrow grass, badan rhizomes in a ratio of 1:1:1: 1 by weight. The quantitative ratio of the components is determined in accordance with the results of the evaluation of the antimicrobial effect of the extract from the proposed collection. To confirm the composition of biologically active substances of the collection, pharmacopoeial qualitative reactions to flavonoids and tannins, as well as the TLC method, which allows identifying substances of a polyphenolic nature, are proposed. The quantitative determination of extractive substances, essential oil, tannins, and flavonoids in the studied collection was carried out and the norms of their content were proposed. The definition of commodity characteristics is carried out.

scholarly journals CRIME AS AN OBJECT OF INQUIRY IN RUSSIAN CRIMINALISTICS ALEKSEY BESSONOV,

2018 ◽  
Vol 5 (2) ◽  
pp. 112-127
Author(s):  
A. Bessonov
Keyword(s):  
Criminal Activity ◽  
Criminal Cases ◽  
New Techniques ◽  
Crime Investigation ◽  
The Subject ◽  
Definition Of ◽  
Object Of Study ◽  
The Relationship ◽  
Modern Russian

This article deals with the definition of the subject and objects of modern Russian criminalistics. It is aimed at sensitizing world public opinion to the necessity of inquiry into the criminalistic essence of crime and encouraging criminalists to study new techniques of crime investigation in order to mitigate risks and reduce errors arising in the criminal investigation process.One of the main objects that is constantly undergoing research in Russian criminalistics is criminal activity. The subject of Russian criminalistics is the regularities of criminal activity. When investigating crimes scientists are interested in the information that allows the successful investigation of the crimes and determination of the offender. The information about different types of crimes, which is necessary for crime investigation, is accumulated in the criminalistic characteristic of crimes. The Criminalistic Characteristic of Crimes is a scientific theory of modern Russian criminalistics that makes it possible to fully examine the specific features of crimes of all kinds, i.e. the forensic nature (essence) of crime, the system of crime elements with their characteristics, and the relationship between those elements. In U.S. and European criminalistics, the regularities of criminal activity are not defined as an object of study of this science. Yet, in the U.S. and European countries criminal profilers investigating criminal cases study the criminal links between crimes to identify crime series and crimes committed by similar offenders (or to determine co-offenders).

scholarly journals DETERMINATION OF FORMALDEHYDE IN WATER BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WITH THE USE OF SOLID PHASE EXTRACTION

2019 ◽  
Vol 96 (3) ◽  
pp. 281-284 ◽  
Author(s):  
P. P. Kochetkov ◽  
A. G. Malysheva ◽  
V. V. Glebov
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
High Performance ◽  
Solid Phase ◽  
Hplc Method ◽  
Phase Extraction ◽  
Definition Of ◽  
Quantitative Definition

The way of definition of formaldehyde in water by the method of high performance liquid chromatography (HPLC) with the use of solid-phase extraction for concoction and extraction of the analyzed derivative formaldehyde is presented. The method is distinguished by the simplified and accelerated procedure of the sample preparation in comparison with classical liquid extraction. Chromatographic division of substances was reached on the turned phase column C18 with the use of mixture of the deionized water and an acetonitrile as a mobile phase. Definition was carried out at absorption wavelength of 360 nanometers. Linearity was reached in the ranges of concentration from 1 to 200 mcg/l. Full validation of a method is carried out. For control samples of all levels, including the lower limit of quantitative definition, the value of repeatability (RSD) accounted for ≤15%. The index of the accuracy amounted to ≤10%. The presented way showed good validation characteristics and can be recommended for the simplification and acceleration of the determination of the content of formaldehyde in water by the HPLC method

Вероятностно-информационный подход к оценке достоверности результатов акустико-эмиссионного метода контроля и диагностики

2021 ◽  
pp. 37-44
Author(s):  
С.И. Буйло ◽  
Б.И. Буйло ◽  
М.И. Чебаков
Keyword(s):  
Acoustic Emission ◽  
Quantitative Determination ◽  
Reliability Assessment ◽  
Amount Of Information ◽  
Traditional Definition ◽  
Information Reliability ◽  
Definition Of

The features of quantitative determination of the reliability of the results of the acoustic emission (AE) method of control and diagnostics are considered. It is established that the traditional definition of reliability through the probability of a controlled parameter falling into a certain interval sometimes suffers from information underdeterminacy. It is shown that taking into account the probabilistic and informational aspects of the reliability assessment makes it possible to unambiguously link the concept of the reliability of the results of control and diagnostics with the amount of information obtained during the control or diagnostic operation itself. Examples of practical determination of the information reliability of the results of the AE method are given.

scholarly journals Possibility for Improving the Planning of the Needs of Food from Bulgarian Army Units when Participating in Humanitarian Operations

2017 ◽  
Vol 22 (1) ◽  
pp. 18-24
Author(s):  
Nikolay Nichev
Keyword(s):  
Armed Forces ◽  
Humanitarian Assistance ◽  
Lessons Learned ◽  
Humanitarian Operations ◽  
Energy Needs ◽  
Seeking Help ◽  
Definition Of ◽  
Object Of Study ◽  
Medical Recommendations

Abstract The extended range of possible tasks before the Bulgarian Army units requires disclosure and enforcement of specific approaches and techniques with which available military resources to be used to assist the civilians, seeking help and protection. This paper is an attempt to define the norms of food for civilians in need of humanitarian assistance. The object of study is planning the Bulgarian army units involved in humanitarian operations. The theme of the study is the definition of food to help civilians seeking help and protection, based on available defense products. To achieve the objective there have been used norms of the armed forces of the Bulgarian army, medical recommendations for food consumption per capita in Bulgaria and the lessons learned with the participation of armed forces in humanitarian operations. For the purpose of the definition of food is necessary to express the need in kilograms. To achieve this task, the analysis is oriented towards the implementation of two subtasks: determination of daily energy needs of an individual, and second - conversion of the necessary calories into food.

scholarly journals Determination of wear of surfaces by scratch testing

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Witold Brostow ◽  
Gowrisankar Darmarla ◽  
Juliet Howe ◽  
Dorota Pietkiewicz
Keyword(s):  
Solid Material ◽  
Mechanical Tests ◽  
Solid Surfaces ◽  
Scratch Testing ◽  
Definition Of ◽  
Quantitative Definition ◽  
Scratch Tests ◽  
Penetration Depths ◽  
Indenter Geometry

Abstract We have formulated a quantitative definition of wear different from the current imprecise definitions. Wear is defined as the unwanted loss of solid material from solid surfaces due to mechanical interaction. The debris method currently used to quantify wear produces results strongly dependent on conditions. We have performed multiple scratch tests for a variety of polymer samples: polypropylene, polytetrafluoroethylene and a polyester. In each of the materials studied, the scratch penetration depths reach a constant value at a given force after 8 scratches or so. Similarly, the scratch recovery (final, healing) depths for a fixed force reach a plateau after a dozen or so scratch tests. Thus, strain hardening by repetitive scratching takes place. A likely explanation is formation of a more ordered phase - as seen before in mechanical tests by Siegmann, Aharoni, Faitelson et al. Given these results we define a measure of wear W(F) for a given indenter geometry and force F as W(F) = limn→∞ Rh(F) where n is the number of tests performed and Rh is the final (residual, healing) depth after viscoelastic recovery. The present results confirm also our earlier ones that scratch recovery is another useful way to characterize viscoelasticity.

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