scholarly journals ANALYSIS OF CALCULATION METHODS FOR DETERMINATION OF SURGE PILE MATERIALS VOLUME

2019 ◽  
Vol 1 (1) ◽  
pp. 203-211
Author(s):  
Valerij Sal'nikov ◽  
Andrej Basargin ◽  
Andrej Astapov
Keyword(s):  
Accurate Method ◽  
Crushed Stone ◽  
Calculation Methods ◽  
Volume Determination ◽  
Volume Calculation ◽  
Parallel Section ◽  
Wet Condition

Nowadays we have to handle the tasks for volume determination of surge pile materials (sand, coal, crushed stone) on industrial objects and building grounds. The type of work is necessary for keeping record of supplied and consumed materials, and also for their piling. This article gives com-parative analysis of 3 calculation methods for land works (horizontal sections, cone, vertical parallel section) in AutoCADCivil 3D. The object of research was the sand, delivered and piled in the Novosibirsk river port. The sand is a rather difficult substance to be calculated as it gets settled down in wet condition and blown away in dry one. The results of the research showed that the most accurate method for sand volume calculation is vertical parallel section one in AutoCADCivil 3D.

scholarly journals Анализ методов расчёта крутильных колебаний судовых валопроводов

2020 ◽  
Vol 44 (3) ◽  
pp. 71-79
Author(s):  
Keyword(s):  
Finite Element ◽  
Accurate Method ◽  
Natural Oscillation ◽  
Calculation Methods ◽  
Oscillating Systems ◽  
Experimental Values ◽  
Similar Accuracy ◽  
Oscillation Frequencies ◽  
Elastic Characteristics

Рассмотрены невыясненные вопросы крутильных колебаний судовых валопроводов с целью повышения точности расчета собственных частот крутильных колебаний путем определения наиболее точного метода приведения системы к дискретному виду. Исследуются две крутильноколеблющиеся системы: экспериментальная установка простой конструкции (двухопорный вал с массами, имеющий привод от электродвигателя) и более сложная – главный пропульсивный комплекс портового буксира РБТ проекта 378. Для этого решается ряд задач: расчет установок двумя методами (с помощью классических уравнений определения инерционных и упругих характеристик системы и программ, использующих методы конечных элементов); торсиографирование названных систем для определения значений экспериментальных значений частот собственных колебаний; сравнительный анализ полученных расчетным и экспериментальным путем значений частот собственных колебаний: на его основе определяются наиболее точные методы расчета. Установлено, что оба рассматриваемых расчетных метода дают результаты приблизительно одной точности. Отмечено, что исследованные модели относительно просты с точки зрения их анализа и определения характеристик. Картина может измениться в случае более сложных систем: тогда один из рассмотренных методов может показать явное преимущество. Ключевые слова: крутильные колебания, метод конечных элементов, судовая энергетическая установка. The outstanding issues of torsion vibrations of vessels' shaft lines in order to improve the accuracy of calculating the natural frequencies of torsion vibrations by determining the most accurate method of reducing the system to the discrete form. Two torsion-oscillating systems are studied: an experimental installation of a simple design (a two – support shaft with weights, driven by an electric motor) and a more complex one – the main propulsive unit of RBT project 378 port tug. With this purpose a number of problems have to be solved: calculation of installations with two methods (using classical equations for determining the inertial and elastic characteristics of the system and programs using finite element methods); torsiography of these systems to determine the values of experimental values of natural oscillation frequencies; comparative analysis of calculated and experimental values of natural oscillation frequencies and determination of the most accurate calculation methods on its basis. It has been found that both calculation methods being considered lead to results of approximately similar accuracy. It is noted that the studied models are relatively simple in terms of their analysis and characterization. The picture may change in the case of more complex systems: then one of the methods considered may show a clear advantage. Keywords: torsion vibrations, finite element method, ship power plant.

scholarly journals Suitability of Aerial Photogrammetry for Dump Documentation and Volume Determination in Large Areas

2021 ◽  
Vol 11 (14) ◽  
pp. 6564
Author(s):  
Ľudovít Kovanič ◽  
Peter Blistan ◽  
Martin Štroner ◽  
Rudolf Urban ◽  
Monika Blistanova
Keyword(s):  
Cross Sections ◽  
Laser Scanning ◽  
Reference Method ◽  
Accurate Method ◽  
Volume Determination ◽  
Aerial Photogrammetry ◽  
Aerial Vehicle ◽  
The Difference

The study presented in this paper analyses the results of measurements and data processing for documentation and quantification of material in heaps in large areas, where UAVs may no longer be effective due to a large range. Two test heaps were selected from a whole area, where the aim was to confirm the suitability of using the method of digital aerial photogrammetry by manned (crewed) aerial vehicle. For comparison, a commonly used GNSS RTK method was also used. Terrestrial laser scanning was chosen as the control reference method. TLS measurement is a trusted method with high accuracy. The methods were compared with each other through the quality of the mesh, analysis of the cross-sections, and comparison of the volumes of heaps. As a result, the determination of heap volumes and documentation using digital aerial photogrammetry can be confirmed as an appropriate, efficient, fast, and accurate method. The difference in the detected volume was less than 0.1%, the mean difference of the meshes was less than 0.01 m, and the standard deviation was less than 0.05 m.

Phosphino-Triazole Ligands for Palladium-Catalysed Cross-Coupling

2018 ◽  
Author(s):  
Yiming Zhao ◽  
Huy van Nguyen ◽  
Louise Male ◽  
Philip Craven ◽  
Benjamin R. Buckley ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Cross Coupling ◽  
Product Formation ◽  
Coupling Reactions ◽  
Volume Determination ◽  
Online Tool ◽  
Triazole Derivatives ◽  
Cross Coupling Reactions ◽  
Modelling Approaches

<div>Twelve 1,5-disubtituted and fourteen 5-substituted 1,2,3-triazole derivatives bearing diaryl or dialkyl phosphines at the 5-position were synthesised and used as ligands for palladium-catalysed Suzuki-Miyaura cross-coupling reactions. Bulky substrates were tested, and lead-like product formation was demonstrated. The online tool SambVca 2.0 was used to assess steric parameters of ligands and preliminary buried volume determination using XRD obtained data in a small number of cases proved to be informative. Two modelling approaches were compared for the determination of</div><div>the buried volume of ligands where XRD data was not available. An approach with imposed steric restrictions was found to be superior in leading to buried volume determinations that closely correlate with observed reaction conversions. The online tool LLAMA was used to determine lead-likeness of potential Suzuki-Miyaura cross-coupling products, from which ten of the most lead-like were successfully synthesised. Thus, confirming these readily accessible triazole-containing phosphines as highly suitable ligands for reaction screening and optimisation in drug discovery campaigns.</div>

Development of HPLC Method for the Purity Test by Design of Experiments and Determination of Activation Energy of Hydrolytic Degradation Reactions of Sofosbuvir

2020 ◽  
Vol 16 (7) ◽  
pp. 976-987
Author(s):  
Jakub Petřík ◽  
Jakub Heřt ◽  
Pavel Řezanka ◽  
Filip Vymyslický ◽  
Michal Douša
Keyword(s):  
Activation Energy ◽  
Design Of Experiments ◽  
Mobile Phase ◽  
Hydrolytic Degradation ◽  
Isoconversional Method ◽  
Hplc Method ◽  
Organic Modifier ◽  
Calculation Methods ◽  
Degradation Reactions

Background: The present study was focused on the development of HPLC method for purity testing of sofosbuvir by the Design of Experiments and determination of the activation energy of hydrolytic degradation reactions of sofosbuvir using HPLC based on the kinetics of sofosbuvir degradation. Methods: Following four factors for the Design of Experiments were selected, stationary phase, an organic modifier of the mobile phase, column temperature and pH of the mobile phase. These factors were examined in two or three level experimental design using Modde 11.0 (Umetrics) software. The chromatographic parameters like resolution, USP tailing and discrimination factor were calculated and analysed by partial least squares. The chromatography was performed based on Design of Experiments results with the mobile phase containing ammonium phosphate buffer pH 2.5 and methanol as an organic modifier. Separation was achieved using gradient elution on XBridge BEH C8 at 50 °C and a flow rate of 0.8 mL/min. UV detection was performed at 220 nm. The activation energy of hydrolytic degradation reactions of sofosbuvir was evaluated using two different calculation methods. The first method is based on the slope of dependence of natural logarithm of the rate constant on inverted thermodynamic temperature and the second approach is the isoconversional method. Results and Conclusion: Calculated activation energies were 77.9 ± 1.1 kJ/mol for the first method and 79.5 ± 3.2 kJ/mol for the isoconversional method. The results can be considered to be identical, therefore both calculation methods are suitable for the determination of the activation energy of degradation reactions.

Development of an HPLC-UV Method for Quantification of Stattic

2019 ◽  
Vol 15 (6) ◽  
pp. 568-573
Author(s):  
Soheil Sedaghat ◽  
Ommoleila Molavi ◽  
Akram Faridi ◽  
Ali Shayanfar ◽  
Mohammad Reza Rashidi
Keyword(s):  
High Performance ◽  
Accurate Method ◽  
Plasma Samples ◽  
Promising Target ◽  
Relative Standard ◽  
Dimerization Inhibitor ◽  
Oncogenic Protein ◽  
First Time ◽  
Transcription 3

Background: Signal transducer and activator of transcription 3 (STAT3), an oncogenic protein found constitutively active in many types of human malignancies, is considered to be a promising target for cancer therapy. Objective: In this study for the first time, a simple and accurate method has been developed for the determination of a STAT3 dimerization inhibitor called stattic in aqueous and plasma samples. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase, and the mixture of acetonitrile (60%) and water (40%) as mobile phase with a UV detection at 215 nm were applied for quantification of stattic. The developed method was validated by Food and Drug Administration (FDA) guideline. Results: The method provided a linear range between 1-40 and 2.5-40 µg mL-1 for aqueous and plasma samples, respectively, with a correlation coefficient of 0.999. The accuracy (as recovery) of the developed method was found to be between 95-105% for aqueous medium and 85-115% for plasma samples. The precision (as relative standard deviation) for aqueous and plasma samples was less than 6% and 15%, respectively. The sensitivity of the developed method based on FDA guideline was 1 µg mL-1 for aqueous and 2.5 µg mL-1 for plasma samples. Conclusion: These results show that the established method is a fast and accurate quantification for stattic in aqueous and plasma samples.

Is it necessary to calculate Young’s modulus in AFM nanoindentation experiments regarding biological samples?

2020 ◽  
Vol 12 ◽  
Author(s):  
S.V. Kontomaris ◽  
A. Malamou ◽  
A. Stylianou
Keyword(s):  
Young’S Modulus ◽  
Biological Samples ◽  
Young's Modulus ◽  
Reference Sample ◽  
Nonlinear Behavior ◽  
Accurate Method ◽  
Accurate Solution ◽  
Hertz Model ◽  
Work Done

Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require very heavy workload and highly specialized personnel. Objective: In this paper a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for the mechanical characterization at the nanoscale. Method: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters. Results: The proposed approach, not only provides an accurate solution from a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip. Conclusion: The proposed, by this opinion paper, solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.

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