Thermoelectrical properties of graphene knife-coated cellulosic fabrics for defect monitoring in Joule-heated textiles

2022 ◽  
pp. 152808372110569
Author(s):  
Tamara Ruiz-Calleja ◽  
Rocío Calderón-Villajos ◽  
Marilés Bonet-Aracil ◽  
Eva Bou-Belda ◽  
Jaime Gisbert-Payá ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Temperature Increase ◽  
Low Voltage ◽  
Industrial Applications ◽  
Protective Equipment ◽  
Voltage Application ◽  
Useful Life ◽  
Coated Fabrics ◽  
Conductive Particles

Knife-coating can confer new properties on different textile substrates efficiently by integrating various compounds into the coating paste. Graphene nanoplatelets (GNP) is one of the most used elements for the functionalization of fabrics in recent years, providing electrical and thermal conductivity to fabrics, later used to develop products such as sensors or heated garments. This paper reports thermoelectrically conductive textiles fabrication through knife-coating of cellulosic fabrics with a GNP load from 0.4 to 2 wt% within an acrylic coating paste. The fabric doped with the highest GNP content reaches a temperature increase of 100°C in few seconds. Besides, it is found out that the thermographic images obtained during the electrical voltage application provide maps of irregularities in the dispersion of conductive particles of the coating and defects produced throughout their useful life. Therefore, the application of a low voltage on the coated fabrics allows fast and effective heating by Joule’s effect, whose thermographic images, in turn, can be used as structural maps to check the quality of the GNP doped coating. The temperature values and the heating rate obtained make these fabrics suitable for heating devices, anti-ice and de-ice systems, and protective equipment, which would be of great interest for industrial applications.

REORGANIZATION OF A MULTI-SPECIALTY HOSPITAL IN AN UNFAVORABLE EPIDEMIOLOGICAL SITUATION

2020 ◽  
pp. 43-46
Author(s):  
Nikitin A.E. ◽  
Znamenskiy I.А ◽  
Shikhova Yu.A. ◽  
Kuzmina I.V. ◽  
Melchenko D.S. ◽  
...  
Keyword(s):  
Contact Time ◽  
Laboratory Diagnostics ◽  
Protective Equipment ◽  
Timely Manner ◽  
High Quality ◽  
Institu Tions ◽  
Quality Of Medical Care ◽  
Spread Of Infection ◽  
Epidemiological Situation

This study provides a retrospective analysis of work to ensure high quality of medical care in an unfavorable epidemic situation. The consequence of COVID-19 was the implementation of a program to prevent the spread of infection, the re-profiling of medical institu-tions, and the introduction of restrictive and anti-epidemic measures. The experience of our work has shown the effectiveness of changing the order of med-ical care, the organization of the functioning of de-partments and patient routing. The study reflects the measures implemented in the hospital departments, the Department of clinical and laboratory diagnostics, radiation diagnostics and pathology Department. To ensure the safety of patients, it was decided to place patients on a single bed according to the type of infec-tious boxes. The safety of employees was ensured by the use of personal protective equipment, minimiza-tion of contact time with patients, and preventive weekly examination of staff for SARS-CoV-2 infection. The organized and well-coordinated work of the en-tire staff of the institution made it possible to prevent the spread of COVID-19 among employees, to detect cases of infection in a timely manner, and to carry out appropriate isolation and monitoring measures. At the time of completion of infectious diseases departments, the mortality rate among patients was less than 9%. Our experience in reorganizing a multi-specialty facil-ity can be used in the future when working with pa-tients who have undergone COVID-19, as well as in the context of a worsening epidemic situation.

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

scholarly journals Optimization of the composition in a composite material for microelectronics application using the Ising model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshihiko Imanaka ◽  
Toshihisa Anazawa ◽  
Fumiaki Kumasaka ◽  
Hideyuki Jippo
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Ising Model ◽  
Specific Gravity ◽  
Simulated Annealing Algorithm ◽  
Optimization Problems ◽  
Industrial Applications ◽  
Thermal Dissipation ◽  
Materials Informatics ◽  
Combinatorial Optimization Problems

AbstractTailored material is necessary in many industrial applications since material properties directly determine the characteristics of components. However, the conventional trial and error approach is costly and time-consuming. Therefore, materials informatics is expected to overcome these drawbacks. Here, we show a new materials informatics approach applying the Ising model for solving discrete combinatorial optimization problems. In this study, the composition of the composite, aimed at developing a heat sink with three necessary properties: high thermal dissipation, attachability to Si, and a low weight, is optimized. We formulate an energy function equation concerning three objective terms with regard to the thermal conductivity, thermal expansion and specific gravity, with the composition variable and two constrained terms with a quadratic unconstrained binary optimization style equivalent to the Ising model and calculated by a simulated annealing algorithm. The composite properties of the composition selected from ten constituents are verified by the empirical mixture rule of the composite. As a result, an optimized composition with high thermal conductivity, thermal expansion close to that of Si, and a low specific gravity is acquired.

scholarly journals Safe On-Boat Resuscitation by Lifeguards in COVID-19 Era: A Pilot Study Comparing Three Sets of Personal Protective Equipment

2021 ◽  
pp. 1-7
Author(s):  
Roberto Barcala-Furelos ◽  
Cristian Abelairas-Gómez ◽  
Alejandra Alonso-Calvete ◽  
Francisco Cano-Noguera ◽  
Aida Carballo-Fazanes ◽  
...  
Keyword(s):  
Pilot Study ◽  
Cardiopulmonary Resuscitation ◽  
Severe Acute Respiratory Syndrome ◽  
Personal Protective Equipment ◽  
High Efficiency ◽  
Prehospital Care ◽  
Protective Equipment ◽  
Preparation Time

Abstract Introduction: On-boat resuscitation can be applied by lifeguards in an inflatable rescue boat (IRB). Due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) and recommendations for the use of personal protective equipment (PPE), prehospital care procedures need to be re-evaluated. The objective of this study was to determine how the use of PPE influences the amount of preparation time needed before beginning actual resuscitation and the quality of cardiopulmonary resuscitation (CPR; QCPR) on an IRB. Methods: Three CPR tests were performed by 14 lifeguards, in teams of two, wearing different PPE: (1) Basic PPE (B-PPE): gloves, a mask, and protective glasses; (2) Full PPE (F-PPE): B-PPE + a waterproof apron; and (3) Basic PPE + plastic blanket (B+PPE). On-boat resuscitation using a bag-valve-mask (BVM) and high efficiency particulate air (HEPA) filter was performed sailing at 20km/hour. Results: Using B-PPE takes less time and is significantly faster than F-PPE (B-PPE 17 [SD = 2] seconds versus F-PPE 69 [SD = 17] seconds; P = .001), and the use of B+PPE is slightly higher (B-PPE 17 [SD = 2] seconds versus B+PPE 34 [SD = 6] seconds; P = .002). The QCPR remained similar in all three scenarios (P >.05), reaching values over 79%. Conclusion: The use of PPE during on-board resuscitation is feasible and does not interfere with quality when performed by trained lifeguards. The use of a plastic blanket could be a quick and easy alternative to offer extra protection to lifeguards during CPR on an IRB.

scholarly journals Replicating the complexity of natural surfaces: technique validation and applications for biomimetics, ecology and evolution

2018 ◽  
Vol 377 (2138) ◽  
pp. 20180265 ◽  
Author(s):  
Charchit Kumar ◽  
Alejandro Palacios ◽  
Venkata A. Surapaneni ◽  
Georg Bold ◽  
Marc Thielen ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Industrial Applications ◽  
Model Parameters ◽  
Future Directions ◽  
Small Surface ◽  
Surface Information ◽  
Cross Covariance ◽  
Unique Method ◽  
Structural Aspects

The surfaces of animals, plants and abiotic structures are not only important for organismal survival, but they have also inspired countless biomimetic and industrial applications. Additionally, the surfaces of animals and plants exhibit an unprecedented level of diversity, and animals often move on the surface of plants. Replicating these surfaces offers a number of advantages, such as preserving a surface that is likely to degrade over time, controlling for non-structural aspects of surfaces, such as compliance and chemistry, and being able to produce large areas of a small surface. In this paper, we compare three replication techniques among a number of species of plants, a technical surface and a rock. We then use two model parameters (cross-covariance function ratio and relative topography difference) to develop a unique method for quantitatively evaluating the quality of the replication. Finally, we outline future directions that can employ highly accurate surface replications, including ecological and evolutionary studies, biomechanical experiments, industrial applications and improving haptic properties of bioinspired surfaces. The recent advances associated with surface replication and imaging technology have formed a foundation on which to incorporate surface information into biological sciences and to improve industrial and biomimetic applications. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology’.

Remaining useful life estimation based on the joint use of an observer and a hidden Markov model

2021 ◽  
pp. 1748006X2110443
Author(s):  
Toufik Aggab ◽  
Pascal Vrignat ◽  
Manuel Avila ◽  
Frédéric Kratz
Keyword(s):  
Markov Models ◽  
Hidden Markov ◽  
Practical Interest ◽  
Markov Property ◽  
Rolling Bearing ◽  
Industrial Applications ◽  
Remaining Useful Life ◽  
Discrete Observations ◽  
Useful Life ◽  
The Difference

We propose an approach for failure prognosis based on the estimation of the Remaining Useful Life (RUL) of a system in a situation in which monitoring signals providing information about its degradation evolution are not measured and no operating model of the system is available. These conditions are of practical interest for industrial applications such as mechanical (e.g. rolling bearing) or electrical (e.g. wind turbine) devices or equipment-critical components (e.g. batteries) in which the addition of sensors to the system is not feasible (e.g. space limitations for sensors, cost, etc.). The approach is based on an estimation of the system degradation using residual generation (where the difference between the system and the observer outputs is processed) and Hidden Markov Models with discrete observations. The prediction of the system RUL is given by the Markov property concerning the mean time before absorption. The approach comprises two phases: a training phase to model the degradation behavior and an “on-line” use phase to estimate the remaining life of the system. Two case studies were conducted for RUL prediction to verify the effectiveness of the proposed approach.

Effects of variable thermal conductivity and electrical conductivity on flow of williamson nanofluid between two parallel disks

2021 ◽  
Author(s):  
Mazmul Hussain ◽  
Nargis Khan
Keyword(s):  
Thermal Conductivity ◽  
Differential Equations ◽  
Electric Conductivity ◽  
Variable Temperature ◽  
Lewis Number ◽  
Variable Thermal Conductivity ◽  
Industrial Applications ◽  
Weissenberg Number ◽  
Modeling And Analysis ◽  
Variable Nature

The variable nature of the thermal conductivity of nanofluid with respect to temperature plays an important role in many engineering and industrial applications including solar collectors and thermoelectricity. Thus, the foremost motivation of this article is to investigate the effects of thermal conductivity and electric conductivity due to variable temperature on the flow of Williamson nanofluid. The flow is considered between two stretchable rotating disks. The mathematical modeling and analysis have been made in the presence of magnetohydrodynamic and thermal radiation. The governing differential equations of the problem are transformed into non-dimensional differential equations by using similarity transformations. The transformed differential equations are thus solved by a finite difference method. The behaviors of velocity, temperature and concentration profiles due to various parameters are discussed. For magnetic parameter, the radial and tangential velocities have showed decreasing behavior, while converse behavior is observed for axial velocity. The temperature profile shows increasing behavior due to an increase in the Weissenberg number, heat generation parameter and Eckert number, while it declines by increasing electric conductivity parameter. The nanoparticle concentration profile declines due to an increase in the Lewis number and Reynolds number.

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