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 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.

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.

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

Glucose Calibration Modeling in Blood with Spline Regression Approaching to Non-Invasive Tools

2018 ◽  
pp. 144-149
Author(s):  
Ria Hayatun Nur ◽  
Indahwati A ◽  
Erfiani A
Keyword(s):  
Diabetes Mellitus ◽  
Linear Regression ◽  
Good Health ◽  
Cubic Spline ◽  
The Body ◽  
Spline Regression ◽  
Linear Quadratic ◽  
Important Thing ◽  
Non Invasive

In this globalization era, health is the most important thing to be able to run various activities. Without good health, this will hinder many activities. Diabetes mellitus is one of the diseases caused by unhealty lifestyle.There are many treatments that can be done to prevent the occurrence of diabetes. The treatments are giving the insulin and also checking the glucose rate to the patients.Checking the glucose rate needs the tools which is safety to the body. This research want to develop non invasive tool which is safety and do not injure the patient. The purpose of this research is also finding the best model which derived from Linear, Quadratic, and Cubic Spline Regression. Some respondents were taking to get the glucose measuring by invasive and non invasive tools. It could be seen clearly that Spline Linear Regression was the best model than Quadratic and Cubic Spline Regression. It had 70% and 33.939 for R2 and RMSEP respectively.

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.

scholarly journals Theoretical and Experimental Studies on MEMS Variable Cross-Section Cantilever Beam Based Piezoelectric Vibration Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 772
Author(s):  
Xianming He ◽  
Dongxiao Li ◽  
Hong Zhou ◽  
Xindan Hui ◽  
Xiaojing Mu
Keyword(s):  
Power Density ◽  
Cantilever Beam ◽  
Cross Section ◽  
Energy Harvester ◽  
Variable Cross Section ◽  
Vibration Energy ◽  
Variable Cross ◽  
Vibration Energy Harvester ◽  
Piezoelectric Vibration Energy Harvester ◽  
Piezoelectric Vibration

The piezoelectric vibration energy harvester (PVEH) based on the variable cross-section cantilever beam (VCSCB) structure has the advantages of uniform axial strain distribution and high output power density, so it has become a research hotspot of the PVEH. However, its electromechanical model needs to be further studied. In this paper, the bidirectional coupled distributed parameter electromechanical model of the MEMS VCSCB based PVEH is constructed, analytically solved, and verified, which laid an important theoretical foundation for structural design and optimization, performance improvement, and output prediction of the PVEH. Based on the constructed model, the output performances of five kinds of VCSCB based PVEHs with different cross-sectional shapes were compared and analyzed. The results show that the PVEH with the concave quadratic beam shape has the best output due to the uniform surface stress distribution. Additionally, the influence of the main structural parameters of the MEMS trapezoidal cantilever beam (TCB) based PVEH on the output performance of the device is theoretically analyzed. Finally, a prototype of the Aluminum Nitride (AlN) TCB based PVEH is designed and developed. The peak open-circuit voltage and normalized power density of the device can reach 5.64 V and 742 μW/cm3/g2, which is in good agreement with the theoretical model value. The prototype has wide application prospects in the power supply of the wireless sensor network node such as the structural health monitoring system and the Internet of Things.

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