Theory and practice of adhesive interactions in the field of milk processing

2021 ◽  
pp. 22-24
Author(s):  
Ольга Борисовна Федотова
Keyword(s):  
Boundary Layer ◽  
Adhesive Strength ◽  
Adhesive Contact ◽  
Adhesive Joints ◽  
Theory And Practice ◽  
Milk Processing ◽  
Engineering And Technology ◽  
Practical Research ◽  
Adhesive Ability ◽  
Adhesive Interactions

Механизмы формирования адгезионного контакта, изучение адгезионной способности тех или других веществ и управление ею в различных технологических процессах, формирование требуемой адгезионной прочности соединений - это многообразные проблемы в области техники и технологии. Рассмотрены понятие «адгезия» и базовые теории адгезионных взаимодействий, базирующихся на различных подходах: молекулярная, которая также называется адсорбционной, диффузионная, механическая, химическая, электрическая, релаксационная, слабого граничного слоя. Универсальности в объяснении тех или иных процессов формирования адгезионных соединений нет. Адгезионные соединения, образуемые в процессе переработки молока, носят нежелательный характер и приводят к потерям продукции и нарушению санитарно-гигиенического состояния производств вследствие образования белковых, жировых и комбинированных загрязнений на поверхностях различного оборудования. Соответственно требуются глубокие научные и практические исследования как по изучению механизмов образования адгезионных соединений, так и по их удалению. Interaction with other people the mechanisms of adhesive contact, the study of the adhesive ability of different substances and the control of adhesion in various technological processes and ensuring the necessary adhesive strength of joints is a multifaceted problem in the fields of engineering and technology. The article discusses the concept of «adhesion» and the basic theory of adhesion coupled interactions, based on various approaches.Molecular, which is also called adsorptive; diffusion, mechanical, chemical, electrical, relaxation, weak boundary layer. There is no universality in explaining certain processes of the formation of adhesive joints.Adhesive joints formed during milk processing are undesirable and lead to product losses and a violation of the sanitary and hygienic state of production. This is due to the formation of protein, fat and combined contaminants on the surfaces of various equipment. Accordingly, deep scientific and practical research is required both to study the mechanisms of the formation of adhesive joints and to remove them.

Attractive forces slow contact formation between deformable bodies underwater

2021 ◽  
Vol 118 (41) ◽  
pp. e2104975118
Author(s):  
Mengyue Sun ◽  
Nityanshu Kumar ◽  
Ali Dhinojwala ◽  
Hunter King
Keyword(s):  
Three Dimensional ◽  
Adhesive Contact ◽  
Final State ◽  
Underwater Adhesion ◽  
Frustrated Total Internal Reflection ◽  
Solid Deformation ◽  
Hydrophilic Surfaces ◽  
Deformable Bodies ◽  
Adhesive Interactions

Thermodynamics tells us to expect underwater contact between two hydrophobic surfaces to result in stronger adhesion compared to two hydrophilic surfaces. However, the presence of water changes not only energetics but also the dynamic process of reaching a final state, which couples solid deformation and liquid evacuation. These dynamics can create challenges for achieving strong underwater adhesion/friction, which affects diverse fields including soft robotics, biolocomotion, and tire traction. Closer investigation, requiring sufficiently precise resolution of film evacuation while simultaneously controlling surface wettability, has been lacking. We perform high-resolution in situ frustrated total internal reflection imaging to track underwater contact evolution between soft-elastic hemispheres of varying stiffness and smooth–hard surfaces of varying wettability. Surprisingly, we find the exponential rate of water evacuation from hydrophobic–hydrophobic (adhesive) contact is three orders of magnitude lower than that from hydrophobic–hydrophilic (nonadhesive) contact. The trend of decreasing rate with decreasing wettability of glass sharply changes about a point where thermodynamic adhesion crosses zero, suggesting a transition in mode of evacuation, which is illuminated by three-dimensional spatiotemporal height maps. Adhesive contact is characterized by the early localization of sealed puddles, whereas nonadhesive contact remains smooth, with film-wise evacuation from one central puddle. Measurements with a human thumb and alternatively hydrophobic/hydrophilic glass surface demonstrate practical consequences of the same dynamics: adhesive interactions cause instability in valleys and lead to a state of more trapped water and less intimate solid–solid contact. These findings offer interpretation of patterned texture seen in underwater biolocomotive adaptations as well as insight toward technological implementation.

Methodology for determining of adhesion strength of polymeric hardening-curing composite materials and adhesive join

2021 ◽  
pp. 181-183
Author(s):  
A.M. Mikhal’chenkov ◽  
I.V. Kozarez ◽  
S.A. Fes’kov ◽  
M.A. Mikhal’chenkova
Keyword(s):  
Composite Materials ◽  
Polymer Composites ◽  
Adhesion Strength ◽  
Adhesive Strength ◽  
Adhesive Joints ◽  
Breaking Force ◽  
Force Moment

The developed technique for determining the adhesive strength allows us to study both adhesive polymer composites and adhesive joints on the same device without the influence of the breaking force moment on the results obtained.

scholarly journals A note on the effect of surface topography on adhesion of hard elastic rough bodies with low surface energy

2019 ◽  
Vol 28 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Guido Violano ◽  
Giuseppe Demelio ◽  
Luciano Afferrante
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Adhesive Contact ◽  
Low Surface Energy ◽  
Surface Gradient ◽  
Self Consistent ◽  
Remarkable Result ◽  
Roughness Amplitude ◽  
Adhesive Interactions ◽  
Effect Of Surface

AbstractAdhesion between bodies is strongly influenced by surface roughness. In this note, we try to clarify how the statistical properties of the contacting surfaces affect the adhesion under the assumption of long-range adhesive interactions.Specifically, we show that the adhesive interactions are influenced only by the roughness amplitude hrms, while the rms surface gradient h0rmsonly affects the non-adhesive contact force. This is a remarkable result if one takes into account the intrinsic difficulty in defining $h_{\mathrm{rms}}^{^{\prime }}.$Results are also corroborated by a comparison with self-consistent numerical calculations.

Chemical Force Microscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 1253-1254
Author(s):  
Charles M. Lieber ◽  
Dmitri Vezenov ◽  
Aleksandr Noy ◽  
Charles Sanders
Keyword(s):  
Functional Groups ◽  
Adhesive Contact ◽  
Adhesion Forces ◽  
Friction Forces ◽  
Force Microscopy ◽  
Chemical Force Microscopy ◽  
Water Solvent ◽  
Assembled Monolayers ◽  
Adhesive Interactions ◽  
Chemical Force

Chemical force microscopy (CFM) has been used to measure adhesion and friction forces between probe tips and substrates covalently modified with self-assembled monolayers (SAMs) that terminate in distinct functional groups. Probe tips have been modified with SAMs using a procedure that involves coating commercial Si3N4 cantilever/tip assemblies with a thin layer of polycrystalline Au followed by immersion in a solution of a functionalized thiol. This methodology provides a reproducible means for endowing the probe with different chemical functional groups.A force microscope has been used to characterize the adhesive interactions between probe tips and substrates that have been modified with SAMs which terminate with COOH and CH3 functional groups in ethanol water solvent. Force versus distance curves recorded under ethanol show that the interaction between COOH/COOH > CH3/CH3 > COOH/CH3. The measured adhesive forces were found to agree well with predictions of the Johnson, Kendall, and Roberts (JKR) theory of adhesive contact, and thus show that the observed adhesion forces correlate with the surface free energy

Deformation of Pyramidal PDMS Stamps During Microcontact Printing

2016 ◽  
Vol 83 (7) ◽  
Author(s):  
Congrui Jin ◽  
Qichao Qiao
Keyword(s):  
Soft Lithography ◽  
Microcontact Printing ◽  
Low Cost ◽  
Transversely Isotropic ◽  
Simulation Method ◽  
Adhesive Contact ◽  
Pdms Stamp ◽  
Numerical Studies ◽  
Assembled Monolayers ◽  
Adhesive Interactions

Microcontact printing (MicroCP) is a form of soft lithography that uses the relief patterns on a master polydimethylsiloxane (PDMS) stamp to form patterns of self-assembled monolayers (SAMs) of ink on the surface of a substrate through conformal contact. Pyramidal PDMS stamps have received a lot of attention in the research community in recent years, due to the fact that the use of the pyramidal architecture has multiple advantages over traditional rectangular and cylindrical PDMS stamps. To better understand the dynamic MicroCP process involving pyramidal PDMS stamps, in this paper, numerical studies on frictionless adhesive contact between pyramidal PDMS stamps and transversely isotropic materials are presented. We use a numerical simulation method in which the adhesive interactions are represented by an interaction potential and the surface deformations are coupled by using half-space Green's functions discretized on the surface. It shows that for pyramidal PDMS stamps, the contact area increases significantly with increasing applied load, and thus, this technique is expected to provide a simple, efficient, and low-cost method to create variable two-dimensional arrays of dot chemical patterns for nanotechnology and biotechnology applications. The DMT-type and Johnson–Kendall–Roberts (JKR)-type-to-DMT-type transition regimes have been explored by conducting the simulations using smaller values of Tabor parameters.

Robust Strategies for Automated AFM Force Curve Analysis—II: Adhesion-Influenced Indentation of Soft, Elastic Materials

2007 ◽  
Vol 129 (6) ◽  
pp. 904-912 ◽  
Author(s):  
David C. Lin ◽  
Emilios K. Dimitriadis ◽  
Ferenc Horkay
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Full Range ◽  
Soft Materials ◽  
Adhesive Contact ◽  
Colloid Interface ◽  
Inhomogeneous Materials ◽  
Dugdale Model ◽  
Normal Contact ◽  
Adhesive Interactions

In the first of this two-part discourse on the extraction of elastic properties from atomic force microscopy (AFM) data, a scheme for automating the analysis of force-distance curves was introduced and experimentally validated for the Hertzian (i.e., linearly elastic and noninteractive probe-sample pairs) indentation of soft, inhomogeneous materials. In the presence of probe-sample adhesive interactions, which are common especially during retraction of the rigid tip from soft materials, the Hertzian models are no longer adequate. A number of theories (e.g., Johnson–Kendall–Roberts and Derjaguin–Muller–Toporov), covering the full range of sample compliance relative to adhesive force and tip radius, are available for analysis of such data. We incorporated Pietrement and Troyon’s approximation (2000, “General Equations Describing Elastic Indentation Depth and Normal Contact Stiffness Versus Load,” J. Colloid Interface Sci., 226(1), pp. 166–171) of the Maugis–Dugdale model into the automated procedure. The scheme developed for the processing of Hertzian data was extended to allow for adhesive contact by applying the Pietrement–Troyon equation. Retraction force-displacement data from the indentation of polyvinyl alcohol gels were processed using the customized software. Many of the retraction curves exhibited strong adhesive interactions that were absent in extension. We compared the values of Young’s modulus extracted from the retraction data to the values obtained from the extension data and from macroscopic uniaxial compression tests. Application of adhesive contact models and the automated scheme to the retraction curves yielded average values of Young’s modulus close to those obtained with Hertzian models for the extension curves. The Pietrement–Troyon equation provided a good fit to the data as indicated by small values of the mean-square error. The Maugis–Dugdale theory is capable of accurately modeling adhesive contact between a rigid spherical indenter and a soft, elastic sample. Pietrement and Troyon’s empirical equation greatly simplifies the theory and renders it compatible with the general automation strategies that we developed for Hertzian analysis. Our comprehensive algorithm for automated extraction of Young’s moduli from AFM indentation data has been expanded to recognize the presence of either adhesive or Hertzian behavior and apply the appropriate contact model.

Sandwich Roof of the Bus – Fatigue and Strength Tests

2016 ◽  
Vol 827 ◽  
pp. 3-6 ◽  
Author(s):  
Karel Doubrava ◽  
Ctirad Novotný
Keyword(s):  
Fatigue Life ◽  
Cyclic Loading ◽  
Numerical Model ◽  
Methyl Methacrylate ◽  
Numerical Simulations ◽  
Shear Test ◽  
Adhesive Joints ◽  
Strength Tests ◽  
Adhesive Ability

Lightweight and safe roof of the bus was solved within the MIT CR: FR-TI4/349 project. Several variants of sandwich roof were tested on samples in a prior period. Several errors of adhesive joints occurred during the production of the bus roof. Methyl methacrylate adhesive was tested with respect to the declared adhesive ability for arbitrary surfaces. Standardised shear test of the adhesive joints were made for tuning of the numerical model. The obtained parameters are used forthe numerical model of sandwich roof segment. Roof segments were loaded by four points bending and experimentally obtained data were compared with the results of numerical simulations. Several specimens were subjected to cyclic loading in order to get approximate fatigue life of tested variants.

scholarly journals Theory and Practice of Using Robotics in Educational Process

2019 ◽  
Vol 28 (6) ◽  
pp. 158-167 ◽  
Author(s):  
E. E. Ruslyakova ◽  
O. V. Pustovoitova ◽  
Yu. P. Kiseleva ◽  
L. A. Yakovleva
Keyword(s):  
Current Trend ◽  
Educational Process ◽  
Theory And Practice ◽  
Project Work ◽  
Fifth Grade ◽  
Fifth Grade Students ◽  
Practical Research ◽  
Pedagogical Research ◽  
Post Industrial ◽  
Robot Assistant

This article discusses the problem of using robotics in higher education, highlights the theoretical and practical aspects of the problem. The article describes the current trend of the inclusion of robotics in the educational process as one of the effective tools for the formation of students’ professional competencies, psychological readiness to implement educational programs at any level in the modern post-industrial world. The authors present psychological and pedagogical research, in which the organization of project work with fourth-grade and fifth-grade students was studied using a robot-assistant. Practical research was devoted to the perception of anthropomorphic robots by students. They studied a number of disciplines in direct contact with a static robot. The authors analyzed the possibility of using robotics in educational process while preparation of students majoring both in engineering and pedagogy. The results of this research support the idea that robots can be assistants for a teacher and motivators for students. Interaction between robot and students enhances their general emotional background, activates cognitive processes and learning in general.

scholarly journals A KEY SEGMENT OF TARGET AUDIENCE IN THE THEORY AND PRACTICE OF CITY BRANDING

2017 ◽  
pp. 70-76
Author(s):  
Viktoriia Koval
Keyword(s):  
Central And Eastern Europe ◽  
Target Audience ◽  
Theory And Practice ◽  
Research Management ◽  
City Branding ◽  
Actual Problem ◽  
Capital Cities ◽  
Practical Research ◽  
Definition Of ◽  
The City

The article examines the actual problem such as definition of a key segment of target audience of territory and city branding. The scientific and publicistic literature on branding has been analyzed. The circle of leading theoreticians who developed the concept of “city branding” and “territory branding” was defined, focusing attention on target audience of this branding. A number of practical campaigns on branding of the capital cities of Central and Eastern Europe were considered. The fact and content of consensus on the key segment of target audience was established, the guiding concept of leading scientific and practical works on branding of the city / territory was indicated. The recommendations on promising areas of scientific and practical research, management decisions, measures to optimize the branding of Ukrainian cities were developed.

scholarly journals Creating a Platform Based Business Model In Dental Industry

2018 ◽  
Vol 4 (1) ◽  
pp. 106
Author(s):  
Galina Fominichna Ostapenko
Keyword(s):  
Business Model ◽  
Practical Experience ◽  
Theory And Practice ◽  
Transformative Change ◽  
Blockchain Technology ◽  
Practical Research ◽  
New Business ◽  
Consumer Services ◽  
First Time ◽  
Platform Economy

Abstract Purpose: The article considers one of the possible approaches to building a fundamentally new business model for dental industry with a concept of a self-organizing industry management system based on blockchain platform, crypto currency and reward for consumer target behavior.Design/methodology/approach: The theoretical design based on literature review, the content analysis and practical experience of business model transformation in digital platform economy and innovative blockchain technology, while the authors develop, describe and implement a new concept of a new business model in dentistry. The factual basis was the materials of an experiment conducted in the Netherlands to create a platform community Dentacoin based on blockchain platform.Findings: The developed concept of the business model in dentistry shows the main mechanisms that make the model attractive to the consumer services: obtaining objective information about services and producers; formation of a contract on the basis of independent diagnostics and its insurance; financial and logistical support of the service.Research/practical implications: The results of theoretical and practical research confirmed the possibility and expediency of the business model innovation of dental industry. The analysis of the current stage of Dentacoin Project implementation shows that business model works.Originality / significance. The proposed concept of business model based on blockchain technology is fundamentally new for the dental industry. It is the first time describe and systemize a new management mechanism of value creation together with utilizing the blockchain advantages. The creation and implementation of the first blockchain-based platform in dentistry allows achieving transformative change of a whole industry and will greatly enrich both the theory and practice of transformational phenomena.JEL Codes: 014, 033, M13

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