FLOW OF WORKING MEDIA THROUGH THE CHANNELS IN THE BODY OF THE ELECTRODE-TOOL

2021 ◽  
pp. 104-110
Author(s):  
В.П. Смоленцев ◽  
Н.С. Поташникова ◽  
И.Г. Стародубцев
Keyword(s):  
High Performance ◽  
Variable Cross Section ◽  
Additive Technologies ◽  
The Body ◽  
Variable Cross ◽  
Electrode Tool ◽  
Mass Removal ◽  
Working Medium ◽  
Working Media ◽  
Processing Zone

Рассмотрен механизм течения жидких и газожидкостных рабочих сред через профильный инструмент для комбинированных методов обработки. Приведены типовые детали, для которых применимы электроды-инструменты с регулируемой подачей рабочей среды в зону обработки, обеспечивающей массовынос продуктов обработки из межэлектродного зазора. За счет применения аддитивных технологий решена проблема изготовления инструмента с внутренними каналами расчетного переменного сечения, обеспечивающими стабильную подачу жидкой (газожидкостной) среды и массовынос продуктов обработки. Предложены новые (на уровне изобретений) способ и электрод-инструмент с управляемой подачей по внутренним каналам рабочей среды, параметры которой рассчитаны с учетом специфики чистовой электроабразивной обработки по схеме копирования профиля детали. Расчетные зависимости для описания механизма течения рабочих сред и методы их использования позволили проектировать электроды-инструменты с профильными каналами, обеспечивающими применение технологических режимов для чистовой обработки инструментом с регулируемой подачей сред и выполнением критерия массовыноса продуктов обработки. Приведенные результаты расчета параметров течения рабочих сред через каналы в инструменте позволили расширить область эффективного использования аддитивных технологий и создать новые (на уровне изобретений) инструменты для электроабразивной обработки по методу копирования и высокопроизводительного одновременного профилирования нескольких поверхностей. Доказана возможность использования энергетической модели для расчета потенциальной составляющей энергии от реализации мощности, затрачиваемой на подкачку рабочей среды, и кинетической энергии от вращения инструмента для получения в зоне обработки требуемой скорости течения жидких (газожидкостных) сред We considered the mechanism of flow of liquid and gas-liquid working media through a profile tool for combined processing methods. We present typical parts for which electrodes-tools are applicable with an adjustable supply of the working medium to the processing zone, which ensures the mass removal of processing products from the interelectrode gap. Through the use of additive technologies, we solved the problem of making a tool with internal channels of a calculated variable cross-section, providing a stable supply of a liquid (gas-liquid) medium and mass removal of processing products. We propose a new (at the level of inventions) method and electrode-tool with a controlled feed through the internal channels of the working medium, the parameters of which are calculated taking into account the specifics of finishing electro-abrasive machining according to the pattern of copying the profile of the part. Calculated dependencies for describing the mechanism of flow of working media and methods of their use made it possible to design electrodes-tools with profile channels that ensure the use of technological modes for finishing with a tool with controlled supply of media and fulfillment of the criterion of mass removal of processing products. The presented results of calculating the parameters of the flow of working media through channels in the tool made it possible to expand the area of effective use of additive technologies and create new (at the level of inventions) tools for electro-abrasive processing using the copying method and high-performance simultaneous profiling of several surfaces. The possibility of using the energy model for calculating the potential component of energy from the implementation of the power spent on pumping the working medium and the kinetic energy from the rotation of the tool has been proved to obtain the required flow rate of liquid (gas-liquid) media in the processing zone

scholarly journals Mass Transport Through Interstitial Structures

2019 ◽  
Vol 24 (4) ◽  
pp. 66-91
Author(s):  
B. Iwanowska-Chomiak ◽  
A. Walicka
Keyword(s):  
Mass Transport ◽  
Structural Parameters ◽  
Primary Source ◽  
Variable Cross Section ◽  
Porous Matrix ◽  
Interstitial Space ◽  
The Body ◽  
Hindrance Factor ◽  
Variable Cross ◽  
Empirical Constant

Abstract Interstitial space, also called interstitum, separating the vital organs of a human body, is the primary source of lymph and is a major fluid compartment in the body. Interstitial space (IS) is filled out by thick collagen (CL) bundles which form lattices represented by a network of capillaries. This network has the structure similar to a sponge porous matrix (SPM) with pores-capillaries of variable cross-section. To analyse the mass transport of interstitial fluids (IFs) through the porous matrix it is assumed that the SPM is composed of an irregular system of pores which may be modelled as a fractal porous matrix. The interstitial fluids can be either bio-suspensions or bio-solutions and therefore they have to be modelled as non-Newtonian fluids. Analysing the fluid flow through the porous matrix it is assumed that the SPM is modelled as capillary tubes of variable radii. Introducing a hindrance factor allowed us to consider the porous matrix as a system of fractal capillaries but of constant radii. Classical and fractal expressions for the flow rate, velocity and permeability are derived based on the physical properties of the capillary model of interstitial structures. Each parameter in the proposed expressions does not contain any empirical constant and has a clear physical meaning, and the proposed fractals models relate the flow properties of the fluids under consideration with the structural parameters of interstitium as a porous medium.

Underwater Acoustic Absorption of Composite Anechoic Layers With Inner Holes

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Changzheng Ye ◽  
Xuewei Liu ◽  
Fengxian Xin ◽  
Tian Jian Lu
Keyword(s):  
Theoretical Model ◽  
Material Properties ◽  
High Performance ◽  
Numerical Study ◽  
High Order Mode ◽  
Variable Cross Section ◽  
Geometrical Parameters ◽  
Variable Cross ◽  
Underwater Acoustic ◽  
Rubber Layer

A combined theoretical and numerical study is carried out to quantify the influence of material properties (e.g., real part and loss factor of Young’s modulus, material density) and geometrical parameters (e.g., layer thickness, height of hole) on the sound absorption performance of an underwater rubber layer containing periodically distributed axial holes. A theoretical model is developed based on the method of transfer matrix as well as the concept of equivalent layering of holes with variable cross section. Numerical simulations with the method of finite elements are subsequently carried out to validate the theoretical model, with good agreement achieved. Physical mechanisms underlying the enhanced acoustic performance of the anechoic layer as a result of introducing the periodic holes are explored in terms of the generated transverse waves and the high-order mode of vibration. The results presented are helpful for designing high-performance underwater acoustic layers with periodically distributed cavities by tailoring relevant material properties and geometrical parameters.

scholarly journals Monitoring of destruction and shallowing of water bodies and bank protection structures in the Volga river delta within the framework of the "Ecology of safe construction" program

2021 ◽  
Vol 47 (4) ◽  
pp. 132-140
Author(s):  
T. V. Zolina ◽  
S. P. Strelkov ◽  
N. V. Kupchikova ◽  
R. I. Shayakhmedov ◽  
K. G. Kondrashin
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
The Body ◽  
Hydropower Plant ◽  
Coastal Protection ◽  
Thermal Imager ◽  
Variable Cross ◽  
Coastal Zones ◽  
Volga River ◽  
Bank Protection

Objective. The article describes the features of works on coastal protection of territories subject to slope processes. The role of research of leading processes of destruction of coastal zones in the framework of the program “The Ecology of Safe Construction and Municipal Services” for forecasting and preventing risks, as well as providing information for further work on building reliable coastal protection, is emphasized. Despite the existing variety of ways to protect embankments from erosion, the search for new technical solutions at the moment continues to be an urgent task.Methods. Geotechnical monitoring of hydraulic structures was carried out. Visual assessments of cracks, slopes of individual structural blocks, and deformations were performed. A thermal imager device is used to search for abnormal temperatures and an electronic hardness meter that measures the strength of concrete.Results. It is determined that the water regime of the Astrakhan Region is characterized by an uneven distribution of runoff due to a direct dependence on the flow rate from the Volgograd hydropower plant. The predominant source of moisture is discharges in the form of a series of rain floods, which often cause flooding. One of the most effective solutions is to preserve the operational characteristics of the bank protection spur-pile of variable cross-section when changing the hydrological river regime. The bank protection spur runs partially movable horizontally and vertically and comprises a head spur in the form of piles of variable height; the body in the form of a floating garland of variable cross-section; the base in the form of a slider block. The design and technological solution allow blocking the coastal stream with the body of the spur at any water level and changing the angle of inclination of the spur with the protected shore.Conclusion. Prevention of emergencies, especially in urbanized areas that are subject to intense anthropogenic impact, is possible only when engineering protective structures are built, which have a positive effect both in protective and environmental aspects.

scholarly journals Design, Fabrication, and Theoretical Investigation of a Cost-Effective Laser Printing Based Colorimetric Paper Sensor for Non-Invasive Glucose and Ketone Detection

2021 ◽  
Author(s):  
Manikuntala Mukhopadhyay ◽  
Sri Ganesh Subramanian ◽  
K. Vijaya Durga ◽  
Debashish Sarkar ◽  
Sunando DasGupta
Keyword(s):  
Colorimetric Detection ◽  
Variable Cross Section ◽  
Porous Matrix ◽  
The Body ◽  
Richards Equation ◽  
Variable Cross ◽  
Detection Zone ◽  
Laser Printing ◽  
Non Invasive ◽  
On Demand

AbstractDiabetes, a chronic condition, is one of the prevalent afflictions of the 21st century, and if left unchecked, this ailment could lead to severe life-threatening complications. A widely accepted methodology for monitoring diabetes is the estimation of the glucose and ketone contents in the body-fluids, viz. blood, urine, etc. Additionally, certain conditions such as starvation, and following a protein rich diet (e.g., keto-diet) could also lead to significant changes in the ketone content, thereby resulting in false-positive diagnosis. Hence, a precise, portable, and on-demand procedure for the rapid and combined estimation of glucose and ketone in the bodily-fluids is of utmost importance. To that end, paper-based analytical devices (μPADs) are promising tools, owing to their multitudinous advantages, and compatibility with biofluids. Although, numerous researchers have contributed substantially in the fundamental investigation, design, and fabrication of μPADs for various applications, a combined platform capable of rapid, accurate and on-demand glucose and ketone detection, that is easy to fabricate, is still relatively unexplored. Moreover, the flow dynamics of an analyte, in combination with enzyme-catalysed (for glucose) and uncatalyzed reactions (for ketone), within a porous paper matrix is also vaguely understood. Herein, we present a facile laser-printing based fabrication of colorimetric sensors on a filter paper, for rapid, and non-invasive estimation of glucose and ketone contents in urine. The urine sample, upon being deposited in a particular expanse, is wicked through the paper matrix, and reacts with specific reagents in the designated zone(s), giving rise to a final color, concomitant with the glucose or ketone content in the sample. The device design enables the liquid to be wicked into the porous matrix in a way that would concentrate the colored product in a dedicated detection zone, thereby augmenting the feasibility for accurate colorimetric detection. Furthermore, we present for the first time, a detailed dynamic model of the flow-field in a variable cross-section paper device using the Richards’ equation, while also considering the species transport and reaction kinetics within the porous media. The results of the numerical simulation agree well with those observed experimentally, thereby validating the present model. Finally, we also developed a web and desktop-based application that would enable the user to upload the images of the colored zones to provide an accurate estimate of the glucose and ketone content in the sample. We believe that our model, in combination with the proposed fabrication methodology, and the in-house developed app., would enable rapid and reliable fabrication of μPADs for various fundamental investigations, and applications pertaining to affordable health-care monitoring.Graphical Abstract

scholarly journals Track design and realization of braiding for three-dimensional variably shaped cross-section preforms

2021 ◽  
Vol 16 ◽  
pp. 155892502110025
Author(s):  
Shao Guowei ◽  
Sun Zhihong ◽  
Zhou Qihong ◽  
Wang Zhenxi ◽  
Wang Bing ◽  
...  
Keyword(s):  
Cross Section ◽  
High Performance ◽  
Three Dimensional ◽  
Variable Cross Section ◽  
Topology Design ◽  
Variable Cross ◽  
Braided Composites ◽  
3D Braided Composites ◽  
Variable Section ◽  
Shaped Cross Section

The preforms of three-dimensional (3D) braided composites have a monolithic structure that is braided with high-performance fibers using 3D braiding technology. Compared with traditional laminate composites, braided composites are widely favored because of their superior overall performance and mechanical properties. The capability of fabricating various yarn structures with a flexible 3D rotary braiding method, however, has not been systematically investigated, especially for a variable-section braiding structure. In accordance with the principles of braiding technology and the characteristics of a 3D braiding structure, in this study, we examined a braiding technology for the production of 3D variably shaped cross-section fabric, focusing on three key factors: the topology design of tracks, the arrangement of carriers, and the matrix algorithm of the braiding of variably shaped cross sections. We calculated new kind of structural synthesis approach to a 3D braiding track for a variable section based on the carrier arrangement characteristic method and completed the entire braiding scheme of the variable cross section. In addition, this approach represents an important step toward a simplified understanding of the carrier motion and the operator-independent operation of a 3D rotary braiding machine.

Improving the efficiency and reliability of electric power generation at incineration plants

2020 ◽  
Vol 12 (4) ◽  
pp. 281-285
Author(s):  
A. V. Martynov ◽  
N. E. Kutko
Keyword(s):  
Low Temperature ◽  
Power Plants ◽  
Thermal Power ◽  
Moscow Region ◽  
Capital Costs ◽  
Working Medium ◽  
The Creation ◽  
Working Media ◽  
Near Future ◽  
Efficiency And Reliability

The article deals with the problem of waste disposal and, accordingly, landfills in the Moscow Region, which have now become the number 1 problem for the environment in Moscow and the Moscow Region. To solve this problem, incineration plants (IP) will be established in the near future. 4 plants will be located in the Moscow Region that will be able to eliminate 2800 thousand tons of waste per year. Burning of waste results in formation of slag making 25% of its volume, which has a very high temperature (1300.1500°C). An arrangement is considered, in which slag is sent to a water bath and heats the water to 50.90°C. This temperature is sufficient to evaporate any low-temperature substance (freons, limiting hydrocarbons, etc.), whereupon the steam of the low-temperature working medium is sent to a turbine, which produces additional electricity. The creation of a low-temperature thermal power plant (TPP) increases the reliability of electricity generation at the IP. The operation of low-temperature TPPs due to the heat of slag is very efficient, their efficiency factor being as high as 40.60%. In addition to the efficiency of TPPs, capital costs for the creation of additional devices at the IP are of great importance. Thermal power plants operating on slag are just such additional devices, so it is necessary to minimize the capital costs of their creation. In addition to equipment for the operation of TPPs, it is necessary to have a working medium in an amount determined by calculations. From the wide variety of working media, which are considered in the article, it is necessary to choose the substance with the lowest cost.

Boundary element method in numerical study of three-dimensional Stokes flows in channels of arbitrary shape

2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Cross Section ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cylindrical Tube ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Periodic Flows ◽  
Element Method

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.

Longitudinal oscillation of a rod with a variable cross section

2019 ◽  
Vol 14 (2) ◽  
pp. 138-141
Author(s):  
I.M. Utyashev
Keyword(s):  
Cross Section ◽  
Natural Frequencies ◽  
Liouville Problem ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Independent Functions ◽  
The Cross ◽  
The Right

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of longitudinal vibrations. The paper presents a method that allows numerically finding the natural frequencies of longitudinal vibrations of an elastic rod with a variable cross section. This method is based on representing the cross-sectional area as an exponential function of a polynomial of degree n. Based on this idea, it was possible to formulate the Sturm-Liouville problem with boundary conditions of the third kind. The linearly independent functions of the general solution have the form of a power series in the variables x and λ, as a result of which the order of the characteristic equation depends on the choice of the number of terms in the series. The presented approach differs from the works of other authors both in the formulation and in the solution method. In the work, a rod with a rigidly fixed left end is considered, fixing on the right end can be either free, or elastic or rigid. The first three natural frequencies for various cross-sectional profiles are given. From the analysis of the numerical results it follows that in a rigidly fixed rod with thinning in the middle part, the first natural frequency is noticeably higher than that of a conical rod. It is shown that with an increase in the rigidity of fixation at the right end, the natural frequencies increase for all cross section profiles. The results of the study can be used to solve inverse problems of restoring the cross-sectional profile from a finite set of natural frequencies.

Evaluation of New 99mTc(CO)3 + Radiolabeled Glycylglycine In Vivo

2019 ◽  
Vol 19 (11) ◽  
pp. 1382-1387
Author(s):  
Ahmet M. Şenışık ◽  
Çiğdem İçhedef ◽  
Ayfer Y. Kılçar ◽  
Eser Uçar ◽  
Kadir Arı ◽  
...  
Keyword(s):  
High Performance ◽  
The Body ◽  
Biological Behavior ◽  
In Vivo Evaluation ◽  
Radiolabeled Peptides ◽  
Tumor Bearing ◽  
Biodistribution Data ◽  
Good Accordance ◽  
Rapid Clearance

Background: Peptide-based agents are used in molecular imaging due to their unique properties, such as rapid clearance from the circulation, high affinity and target selectivity. Many of the radiolabeled peptides have been clinically experienced with diagnostic accuracy. The aim of this study was to investigate in vivo biological behavior of [99mTc(CO)3(H2O)3]+ radiolabeled glycylglycine (GlyGly). Methods: Glycylglycine was radiolabeled with a high radiolabeling yield of 94.69±2%, and quality control of the radiolabeling process was performed by thin layer radiochromatography (TLRC) and High-Performance Liquid Radiochromatography (HPLRC). Lipophilicity study for radiolabeled complex (99mTc(CO)3-Gly-Gly) was carried out using solvent extraction. The in vivo evaluation was performed by both biodistribution and SPECT imaging. Results: The high radiolabelling yield of 99mTc(CO)3-GlyGly was obtained and verified by TLRC and HPLRC as well. According to the in vivo results, SPECT images and biodistribution data are in good accordance. The excretion route from the body was both hepatobiliary and renal. Conclusion: This study shows that 99mTc(CO)3-GlyGly has the potential to be used as a peptide-based imaging agent. Further studies, 99mTc(CO)3-GlyGly can be performed on tumor-bearing animals.

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