scholarly journals The use of mathematical modeling for the construction of a control system for a climate chamber

2019 ◽  
Vol 2 (1) ◽  
pp. 562-569
Author(s):  
Marian Banaś ◽  
Mariusz Filipowicz ◽  
Krzysztof Lalik ◽  
Sławosz Kleszcz ◽  
Szymon Podlasek ◽  
...  

Abstract Due to the introduced political instruments, as well as the increase in awareness and standard of living, mechanical ventilation is becoming more and more popular in Poland. The growing market and standards force the manufacturers of air handling units to constantly improve the quality of their products. In order to verify the operation of these devices, it is necessary in a specially adapted for this object called the climate chamber. Due to the strict regulations regarding the working conditions of the said facilities, it is necessary to apply the processes of advanced control systems in the process of regulation. These processes are aimed at establishing stable parameters of air supplied to the tested objects, ventilation and air-conditioning units such as: temperature, humidity, flux. Due to the need for precise control and operation of the installation in industrial conditions, it was decided to use the PID controller. The article deals with the optimization of the heating and cooling system, because the temperature parameter was a problematic element in the proper operation of the climate chamber. Both the heating and cooling systems have been described and executive elements have been emphasized, thanks to which it was possible to control the flow of circulating factors. The procedure of selection and implementation of the regulator's settings and its influence on the operation of the climate chamber was also analyzed.

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Ghania Henini ◽  
Fatiha Souahi ◽  
Ykhlef Laidani

We present the thermal behavior of a batch reactor to jacket equipped with a monofluid heating/cooling system. Heating and cooling are provided respectively by an electrical resistance and two plate heat exchangers. The control of the temperature of the reaction is based on the supervision system. This strategy of management of the thermal devices is based on the usage of the thermal flux as manipulated variable. The modulation of the monofluid temperature by acting on the heating power or on the opening degrees of an air-to-open valve that delivers the monofluid to heat exchanger. The study shows that the application of this method for the conduct of the pilot reactor gives good results in simulation and that taking into account the dynamics of the various apparatuses greatly improves ride quality of conduct. In addition thermal control of an exothermic reaction (mononitration) shows that the consideration of heat generated in the model representation improve the results by elimination any overshooting of the set-point temperature.


Author(s):  
G. Bertrand ◽  
C. Malavolta ◽  
F. Tourenne ◽  
B. Hansz ◽  
C. Coddet ◽  
...  

Abstract In general, thermal spraying involves high temperatures that can be deleterious for the microstructure and deformation of the substrate. As a consequence, the use of a cooling system during spraying is often necessary. Meanwhile, in some cases, a too low surface temperature can induce a loss of properties, in particular concerning adherence and coating density. Therefore, it would be sometimes interesting to combine pre-heating and cooling stages with the plasma spray. A specific process, named HeatCool, was developed and patented to ensure a precise control of the temperature at the spraying location. The present work was focused on the study of the influence of pre-heating and cryogenic cooling conditions on the microstructure and mechanical characteristics of NiCrFeBSi self-fluxing alloy deposited by d.c. plasma spray technique. Firstly, a comparison between air and CO2 cooling was conducted to assess the efficiency corresponding to the specific use of cryogenic CO2. The main characteristics studied were the microhardness, roughness, porosity, mechanical deformations, morphology and crystallographic structures. Optimising the cooling methods and conditions combined with the process parameters improved microhardness of the plasma sprayed metal alloy and induced lower strain deformation of the substrate. Secondly, the pre-heating system was added to the device and the HeatCool process was evaluated. The process was demonstrated to be an efficient mean to enhance the structural and mechanical characteristics of coatings made of self-fluxing alloy.


Author(s):  
Nataliia Kharytonova ◽  
Olha Mykolaienko ◽  
Tetyana Lozova

Greening of roads contributes to the protection of roads and their elements from influence of adverse weather and climatic factors; it includes the measures for improvement and landscaping of roads, ensures the protection of roadside areas from transport pollution, provides visual orientation of drivers. The solution of these issues will ensure creation and maintenance of safe and comfortable conditions for travelers. Green plantings in the right-of-way road area include woody, bushy, flower and grass vegetation of natural and artificial origin. For proper operation of public roads and satisfaction of other needs of the industry, there may be the need in removing the greenery. The reason for the removal of greenery in the right-of-way road area may be due to the following factors: construction of the architectural object, widening of the motor road, repair works in the security zone of overhead power lines, water supply, drainage, heating, telecommunications facilities, cutting of hazardous, dry and fautal trees, as well as self-grown and brushwood trees with a root neck diameter not exceeding 5 cm, elimination of the consequences of natural disasters and emergencies. The removal of plantations in the right-of-way area is executed in order to ensure traffic safety conditions and to improve the quality of plantations composition and their protective properties. Nowadays, in Ukraine there is no clear procedure for issuing permits for removing of such plantations. In order to resolve this issue, there is a need in determining the list of regulations in the area of forest resources of Ukraine and, if needed, the list of regulatory acts that have to be improved; to prepare a draft of the regulatory legal act that would establish the procedure of plantations cutting, the methodology of their condition determination, recovery costs determination, the features of cutting. Keywords: plantations, cutting, right-of-way, woodcutting permit, order.


2020 ◽  
Vol 16 ◽  
Author(s):  
Wei Liu ◽  
Shifeng Liu ◽  
Yunzhe Li ◽  
Peng Zhou ◽  
Qian ma

Abstract:: Surgery to repair damaged tissue, which is caused by disease or trauma, is being carried out all the time, and a desirable treatment is compelling need to regenerate damaged tissues to further improve the quality of human health. Therefore, more and more research focus on exploring the most suitable bionic design to enrich available treatment methods. 3D-printing, as an advanced materials processing approach, holds promising potential to create prototypes with complex constructs that could reproduce primitive tissues and organs as much as possible or provide appropriate cell-material interfaces. In a sense, 3D printing promises to bridge between tissue engineering and bionic design, which can provide an unprecedented personalized recapitulation with biomimetic function under the precise control of the composition and spatial distribution of cells and biomaterials. This article describes recent progress in 3D bionic design and the potential application prospect of 3D printing regenerative medicine including 3D printing biomimetic scaffolds and 3D cell printing in tissue engineering.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.


2021 ◽  
pp. 111122
Author(s):  
Michal Krajčík ◽  
Martin Šimko ◽  
Ondřej Šikula ◽  
Daniel Szabó ◽  
Dušan Petráš

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hicham Agueny

AbstractCoherent electron displacement is a conventional strategy for processing quantum information, as it enables to interconnect distinct sites in a network of atoms. The efficiency of the processing relies on the precise control of the mechanism, which has yet to be established. Here, we theoretically demonstrate a new route to drive the electron displacement on a timescale faster than that of the dynamical distortion of the electron wavepacket by utilizing attosecond single-cycle pulses. The characteristic feature of these pulses relies on a vast momentum transfer to an electron, leading to its displacement following a unidirectional path. The scenario is illustrated by revealing the spatiotemporal nature of the displaced wavepacket encoding a quantum superposition state. We map out the associated phase information and retrieve it over long distances from the origin. Moreover, we show that a sequence of such pulses applied to a chain of ions enables attosecond control of the directionality of the coherent motion of the electron wavepacket back and forth between the neighbouring sites. An extension to a two-electron spin state demonstrates the versatility of the use of these pulses. Our findings establish a promising route for advanced control of quantum states using attosecond single-cycle pulses, which pave the way towards ultrafast processing of quantum information as well as imaging.


2021 ◽  
Vol 11 (10) ◽  
pp. 4464
Author(s):  
Viritpon Srimaneepong ◽  
Artak Heboyan ◽  
Azeem Ul Yaqin Syed ◽  
Hai Anh Trinh ◽  
Pokpong Amornvit ◽  
...  

The loss of one or multiple fingers can lead to psychological problems as well as functional impairment. Various options exist for replacement and restoration after hand or finger loss. Prosthetic hand or finger prostheses improve esthetic outcomes and the quality of life for patients. Myoelectrically controlled hand prostheses have been used to attempt to produce different movements. The available articles (original research articles and review articles) on myoelectrically controlled finger/hand prostheses from January 1922 to February 2021 in English were reviewed using MEDLINE/PubMed, Web of Science, and ScienceDirect resources. The articles were searched using the keywords “finger/hand loss”, “finger prosthesis”, “myoelectric control”, and “prostheses” and relevant articles were selected. Myoelectric or electromyography (EMG) signals are read by myoelectrodes and the signals are amplified, from which the muscle’s naturally generated electricity can be measured. The control of the myoelectric (prosthetic) hands or fingers is important for artificial hand or finger movement; however, the precise control of prosthetic hands or fingers remains a problem. Rehabilitation after multiple finger loss is challenging. Implants in finger prostheses after multiple finger loss offer better finger prosthesis retention. This article presents an overview of myoelectric control regarding finger prosthesis for patients with finger implants following multiple finger loss.


2021 ◽  
Vol 2 (1) ◽  
pp. 1-25
Author(s):  
Srinivasan Iyengar ◽  
Stephen Lee ◽  
David Irwin ◽  
Prashant Shenoy ◽  
Benjamin Weil

Buildings consume over 40% of the total energy in modern societies, and improving their energy efficiency can significantly reduce our energy footprint. In this article, we present WattScale, a data-driven approach to identify the least energy-efficient buildings from a large population of buildings in a city or a region. Unlike previous methods such as least-squares that use point estimates, WattScale uses Bayesian inference to capture the stochasticity in the daily energy usage by estimating the distribution of parameters that affect a building. Further, it compares them with similar homes in a given population. WattScale also incorporates a fault detection algorithm to identify the underlying causes of energy inefficiency. We validate our approach using ground truth data from different geographical locations, which showcases its applicability in various settings. WattScale has two execution modes—(i) individual and (ii) region-based, which we highlight using two case studies. For the individual execution mode, we present results from a city containing >10,000 buildings and show that more than half of the buildings are inefficient in one way or another indicating a significant potential from energy improvement measures. Additionally, we provide probable cause of inefficiency and find that 41%, 23.73%, and 0.51% homes have poor building envelope, heating, and cooling system faults, respectively. For the region-based execution mode, we show that WattScale can be extended to millions of homes in the U.S. due to the recent availability of representative energy datasets.


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