Dynamic Setup Research Articles

A genetic-simulated annealing algorithm for stochastic seru scheduling problem with deterioration and learning effect

ABSTRACT As a flexible and effective production mode, seru production has been adopted successfully in electronic industry. In practice, the processing time may be affected by many stochastic factors, such as worker absence, shortage of resources, and so on. This paper focuses on seru scheduling problems with stochastic processing time, and considers the influence of dynamic resource allocation, job deterioration, learning effecteffect, and setup time simultaneously to minimize the makespan. A genetic-simulated annealing algorithm is proposed, in which a simulated annealing procedure is constructed to re-optimize the optimal individual obtained by geneticthe genetic algorithm. Experiment results validate the effectiveness of proposedthe proposed seru scheduling model and genetic-simulated annealing algorithm for solving large-scale cases, and indicate that the stochastic processing time has a great influence on the makespan whichmakespan that can help production manager to makeproduce more consistent results according to the actual situation.

Lz‐transform approach to evaluate reliability indices of multi‐state repairable weighted K‐out‐of‐n systems

AbstractA multi‐state weightedK‐out‐of‐nsystem is of great importance in system engineering due to its generalized nature. In earlier studies, usually all the components of the multi‐state weightedK‐out‐of‐nsystem were considered to be in a steady state though we can encounter engineering systems where the components of this type of system can be dynamic in nature, that is, the states of components change over time. To deal with this situation, in the current study an algorithm, based on ‐transform is presented to determine the reliability indices of multi‐state weightedK‐out‐of‐nsystem in dynamic setup. The components of the system are assumed to follow Markov process and are repaired only when they are completely failed. In this proposed study reliability, availability, instantaneous mean expected performance, and performance deficiency are obtained for the considered system. Finally, a case study of the power system of warship is considered to apply and validate the proposed approach.

Performance Analysis of Enterprise Cloud Computing: A Review

Cloud computing has swiftly established itself as the norm in its field as a result of the advantages described above. In an attempt to reduce the amount of time spent on infrastructure upkeep, an increasing number of businesses are moving their operations to the cloud. As a result, maintaining a cloud environment has proved to be exceedingly difficult. It is necessary to have an efficient cloud monitoring system in order to reduce the workload associated with administration and improve cloud operation. The cloud monitoring service is beneficial since it has the potential to improve performance and make administration easier. The administration of Quality of Service (QoS) parameters for cloud-hosted, virtualized, and physical services and applications is one of the most important responsibilities of cloud monitoring. As a result, cloud management software retains a record of both actions and services, and it also conducts dynamic setups of the cloud in order to increase operational effectiveness. The performance of businesses and businesses as a whole was examined in this article, as was the influence that cloud-ready programs and tools have on that performance, as well as the advantages that may be obtained from adopting such programs and products.

Dynamic measurement setups for validating piezoelectric energy harvesters in driving conditions

Sustainable power supply to flexible electronics is currently of high interest due to the transition to autonomous and self-driving vehicles. Piezoelectric Energy Harvesters (PEH) can be used as sustainable energy sources by harvesting the electrical power through the material deformation occurring in a tire. In this work, an analytical setup was developed to experimentally validate the energy harvesters for their use in tires. It was designed to measure the harvested electrical energy under simulated driving conditions. The setup includes a Dynamic Mechanical Analysis (DMA) as foundation to simulate the vibrations and dynamic responses occurring in a rolling tire. The dynamic properties and the output voltage from the harvesters were monitored under these sinusoidal conditions. For this, a PEH for tire applications was prepared in a sandwich configuration. It consists of a piezoelectric material, i.e. PolyVinyliDene diFluoride (PVDF) film, inserted in between two layers of electrodes, i.e. elastomers filled with conductive carbon black fillers. The electrical conductivity of elastomeric compounds was measured under dynamic conditions varying dynamic strain, frequencies, and temperatures. Dynamic strain and temperature resulted to be the most significant factors influencing the electrical conductivity of elastomers. Output power from the piezoelectric energy harvester was also measured at varied frequencies and temperatures. Both properties increase considerably the piezoelectric power. This development gives a promising method for analyzing the electro-mechanical properties of conductive and piezoelectric materials and optimizing their performance according to simulated tire-rolling conditions.

Dynamic expansion of mesenchymal stem/stromal cells in a stirred tank bioreactor promotes the release of potent extracellular vesicles

<abstract> <p>Mesenchymal stem/stromal cell-derived extracellular vesicles (MSC-EVs) are considered a promising therapeutic tool in cell therapy due to their immunomodulatory, regenerative and angiogenic capabilities. However, there is a lack of process knowledge, particularly for a large-scale production of MSC-EV using fully controlled stirred tank bioreactor (STR) systems. For the establishment of a STR-based process, we investigated dynamic process set-ups in spinner flasks, using three different microcarriers, as well as in shaking flasks, using microcarrier-free spheroids. An immortalized cell line (hMSC-TERT) and a particle-free chemically defined medium was used for all approaches. Cell characteristics (e.g., growth, metabolism, cell-specific particle production rates), MSC-EV epitope markers and MSC-EV potency in migration assays were analyzed. We showed that the transfer to a dynamic system (non-porous microcarrier, spinner flask) significantly increased the cell-specific particle production rate (6-fold) and the expression of EV-specific markers. Moreover, MSC proliferation and, most importantly, the therapeutic potency of MSC-derived particles including EVs was maintained. We demonstrated that high cell-specific particle production rates were associated with an increased glucose consumption rate rather than cell growth, which can be utilized for future process development. Furthermore, we showed that dynamic conditions of a controlled 1 L STR significantly increased the cell-specific particle production rate (24-fold) as well as the final concentration (3-fold) of potent MSC-derived particles including EVs. This indicates that fully controlled STRs are an efficient production system for MSC-derived particles including EVs that may open and facilitate the path for clinical applications.</p> </abstract>

Amperometric Measurements by a Novel Aerosol Jet Printed Flexible Sensor for Wearable Applications

In the last years, increasing interest has been addressed on wearable devices for the continuous monitoring of biochemical profiles of patients and athletes. Among various markers, lactate represents one of the most interesting to deepen the knowledge on fatigue processes, in combination with traditional electromyographic features. In this work, we propose a new, low-cost, rapid, and flexible electrochemical amperometric lactate carbon biosensor fabricated by the novel technique of aerosol jet printing (AJP). The developed biosensors were combined with a paper-based microfluidic system and a chitosan-based stable functionalization to allow a long-term continuous monitoring of human daily activities. The sensor performances were evaluated by static and dynamic electrochemical tests in buffered media. The limit of detection is 11 ± 2 mM for the static setup and of 15 ± 6 mM for the dynamic setup, while sensitivity is 0.02 and 0.04 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{A}$ </tex-math></inline-formula> /mM, respectively, with single sigma standard deviation lower than 8%. Increasing and decreasing concentration steps of lactate induces comparable response times below 30 s. These results obtained in vitro under controlled laboratory conditions represent a promising starting point to pursue with ex-vivo and in vivo validation for the future development of stand-alone wearable patches for noninvasive lactate measurements.

Photo-Fenton Degradation Process of Styrene in Nitrogen-Sealed Storage Tank.

Using styrene as a proxy for VOCs, a new method was developed to remove styrene gas in nitrogen atmospheres. The effect on the styrene removal efficiency was explored by varying parameters within the continuum dynamic experimental setup, such as ferrous ion concentration, hydrogen peroxide concentration, and pH values. The by-products are quantized by a TOC analyzer. The optimal process conditions were hydrogen peroxide at 20 mmol/L, ferrous ions at 0.3 mmol/L and pH 3, resulting in an average styrene removal efficiency of 96.23%. In addition, in this study, we construct a BAS-BP neural network model with experimental data as a sample training set, which boosts the goodness-of-fit of the BP neural network and is able to tentatively predict styrene gas residuals for different front-end conditions.

“Impact of γ-radiation on carbon steel anaerobic corrosion and H2 production.”

This article reports investigations on the anoxic corrosion process impacting a carbon steel/ultrapure deaerated water system when it is exposed to gamma radiation (50 Gy h−1), and on the associated molecular hydrogen gas generation. On the one hand, a dynamic semi-open experimental setup allowing to distinguish between the H2 production related to water radiolysis and the one related to anoxic corrosion has been adopted to estimate the corrosion rate associated to three successive temporal phases: pre-irradiation, irradiation and post-irradiation phases. On the other hand, post mortem analyses performed on both liquid and solid samples permitted to (i) quantify the chemical changes occurring in solution due to the formation of water radiolysis products and (ii) observe and characterize the thin corrosion layer composed of magnetite (Fe3O4) at the surface of the metallic coupons. We show that gamma radiation induces a slight diminution of the carbon steel corrosion rate. However, by comparing the mean corrosion rate values obtained for the three studied phases (i.e., before, during and after irradiation), the chemical changes caused by radiolytic species seem to inhibit the formation of a thick magnetite protective layer. Additionally, the corrosion rate observed in post-irradiation phase does not decrease over time, which suggests that irradiation could modify the properties of the corrosion product layer by making it less protective. A structural modification of this oxide film might be caused by the oxidizing water radiolysis products. Such mechanisms may favour continuous active corrosion processes rather than passivation of the metallic surface and thus lead to a reduced lifetime of the component.

Material processing conditions effect on the thermokinetics of end of life tyres

ABSTRACT In this work, end of life tyres (ELTs) samples were subjected to pyrolysis in a dynamic thermogravimetry set-up under various heating rates between 5°C and 25°C min−1. The experimental design involved dried and non-dried sample results in an isothermal step within the heating program, to be able to compare the data against non-dried samples, to further investigate the effect of drying on the results obtained. The drying of the samples resulted in an increase in the onset temperature by some 30°C. However, cryomilling the ELTs samples showed a great effect in reducing the onset of the degradation curve by about 10°C amongst the same set of experiments. The type of sample, in terms of size and processing/milling condition, had a significant impact on the heat flow properties and calorimetry reported. The exothermic region for the original shavings resulted in an enthalpy of −48 J g−1, whilst the cutting mill samples exhibited an enthalpy increase to −184 J g−1. However, the cryomilled samples showed an enthalpy increase estimated at 139 J g−1.

Room-Temperature NO2 Gas Sensors Based on Granulated Carbon Nanofiber Material

Room-temperature gas sensors based on granulated carbon nanofiber material were investigated for the detection of NO2. The granulated material consisting of intertwined carbon nanofibers was synthesized by the decomposition of CH4 over the Ni/Al2O3 catalyst in a vibro-fluidized bed reactor. Carbon material was investigated using transmission electron microscopy, Raman spectroscopy, low-temperature nitrogen adsorption, and X-ray photoelectron spectroscopy. Investigation of the gas sensors towards NO2 at room temperature (25 ± 2 °C) was carried out in a dynamic flow-through setup in the range from 1 to 500 ppm. A comparison of the sensitivity gas sensor to NH3 and CH4 was also given. The sensor based on non-treated carbon nanofiber material showed the response ΔR/R0 of 5.1 % to 10 ppm of NO2. It was found that the sensor response to NO2 decreased when increasing the relative humidity. The effect of the relative humidity was more pronounced for low concentrations of nitrogen dioxide and decreases with a further increase in them.

Land‐Atmosphere Cascade Fueled the 2020 Siberian Heatwave

AbstractA heatwave in Siberia starting in January 2020, initiated by a wave 5 pattern in the jet stream, caused the surface air temperature to reach 38°C in June with important impacts on ecosystems and water resources. Here we show that this dynamical setup started a chain of events leading to this long‐lasting and unusual event: positive temperature anomalies over Siberia caused early snowmelt, leading to substantial earlier vegetation greening accompanied by decreased soil moisture and browning in the summer. This soil moisture depletion and vegetation browning, in turn, increased the impact of the heatwave on the atmosphere through a land‐atmosphere feedback. This line of evidence suggests that large‐scale dynamics and land‐atmosphere interactions both contributed to the magnitude and persistence of this record‐breaking heatwave, in addition to the background global warming impact on mean temperature. Here, we describe a carry‐over effect in Siberia from a spring positive temperature anomaly into summer dryness and browning, with retroaction into the atmosphere. With the Arctic warming twice as fast as the global average, this event foreshadows the future of northern latitude continents and emphasizes the importance of both atmospheric dynamics and land‐atmosphere interactions in the future as the climate changes. More frequent similar events could have major consequences on the carbon cycle in these carbon‐rich northern latitude regions.

Innovation of the Year

This category recognises good design and technology in the vehicle itself. The panel considered hardware, software, engineering and computing innovations that can be applied to advance and enhance vehicle dynamic setups

Development Tool of the Year

Developing a great dynamic setup requires great tools. This category rewards the latest tools that help vehicle dynamics engineers evaluate their designs and setups to achieve automotive excellence. Everything from simulation to durability technology, software to lab machinery, to dynamometers and more is eligible

A label-free light-scattering method to resolve assembly and disassembly of DNA nanostructures

DNA self-assembly, and in particular DNA origami, has evolved into a reliable workhorse for organizing organic and inorganic materials with nanometer precision and with exactly controlled stoichiometry. To ensure the intended performance of a given DNA structure, it is beneficial to determine its folding temperature, which in turn yields the best possible assembly of all DNA strands. Here, we show that temperature-controlled sample holders and standard fluorescence spectrometers or dynamic light-scattering setups in a static light-scattering configuration allow for monitoring the assembly progress in real time. With this robust label-free technique, we determine the folding and melting temperatures of a set of different DNA origami structures without the need for more tedious protocols. In addition, we use the method to follow digestion of DNA structures in the presence of DNase I and find strikingly different resistances toward enzymatic degradation depending on the structural design of the DNA object.

Are zombies for real? Evidence from zombie dynamics

This paper analyses zombie firms in a dynamic setup where firm survival not only depends on its current returns, but the firm's exit decision is forward-looking. Building on a model of firm entry and exit and using firm-level data from Finland, we show that the expected future value and growth of a firm are key determinants in whether it is likely to recover from losses accumulated during a spell of weak performance. We find that including firm growth in zombie identification substantially reduces zombie incidence in the data as one third of low interest coverage ratio firms in a common zombie definition are growing companies. Moreover, over a half of exits from zombie status are recoveries to become healthy firms. A policy that may promote the survival of zombie firms is public subsidies. Our analysis does indeed support the notion that subsidized firms are less likely to die, but also their chances of recovery are higher.

Experimental characterization of diffuse speckle pulsatile flowmetry system

The recently developed Diffuse Speckle Pulsatile Flowmetry (DSPF) technique offers high measurement rates of around 300 Hz for non-invasive blood flow measurement of blood flow in deep tissue (up to a depth of approximately 15 mm), showing promising potential for the monitoring of various pathologies associated with abnormal blood flow. The effects of various parameters associated with this technique such as speckle size and exposure time on the measured flow readings, however, have yet to be studied. In this work, we examine these relationships experimentally, observing that the number of pixels per speckle (a measure of speckle size) and exposure time have a strong inverse relationship and a positive relationship respectively with the measured DSPF readings in no-flow setups using both static single light scattering and multiple light scattering mediums. We also studied how the sensitivity of DSPF readings to flow is affected by these parameters, finding that the number of pixels per speckle and exposure time have an inverse relationship and strong positive linear relationship respectively with the gradient of the regression line between the actual and measured flow rates in a dynamic setup using a tissue-mimicking flow phantom. It is hoped that these results would enable researchers using the DSPF technique to select and utilize the most optimized settings for their specific use applications.

A comparison between static and dynamic stiffness of force transducers for dynamic force calibrations

The dynamic force transducers’ stiffness is an important parameter in determining the frequency range where the force transducers can be used at the different dynamic setups. The aim of the present paper is to demonstrate a new setup and analysis method in measuring the stiffness of the dynamic force transducers under applying static force. This new approach is distinguished by its stability and accuracy as it depends on using primary measurement devices precisely assembled; dead weight machine and laser interferometer device. The measured stiffness value is compared to the dynamic stiffness measured under applying sinusoidal dynamic force to ensure its validity. Results show that there is sensible difference between static and dynamic stiffness. Static stiffness is always greater than the dynamic stiffness. Many factors are affecting the accuracy of the dynamic stiffness such as rocking modes, lateral forces, and the mechanical coupling between force transducer and the electrodynamic shaker.

Investigation of influence of wall temperature on particulate deposition using novel dynamic microscopic setup

This study investigates the influence of the wall temperature on the wax particulate deposition mechanism, analyzing the average deposit thickness, the growth rate, and agglomerates of wax crystals using a state-of-the-art microscopic dynamic in-situ visualization technique. The higher the wall temperature, the lower the growth rate and the thinner the deposit thicknesses formed, showing good agreement with conventional flow-loop observations. Similarly, the higher the wall temperature, the smaller the agglomerates formed in laminar cases. Furthermore, the wall temperature has a more significant influence in the laminar case than turbulent. A reduction of 69.3% on the final average deposit thickness measurements was obtained under the laminar flow regime for an increase of 1.9 °C in the wall temperature, while for turbulent flow regimes, the maximum reduction in average deposit thickness was observed to be no higher than 44.4%, even though the wall temperature was varied 3.2 °C. CFD simulations were conducted to determine the radial temperature profile of the oil, showing that the higher the flow rate becomes, the less variation is observed in the radial temperature. The simulated temperature boundary layer thickness for laminar cases was approximately equal to 4.16 mm, while for the turbulent case it is approximately 2.86 mm.

Principles of Magnetohydrodynamical Control of Internal and External Supersonic Flows

This paper demonstrates the possibility of active magnetohydrodynamic (MHD) control of supersonic flows containing shock waves. The shock wave configurations that occur at the inlet to a supersonic diffuser and in front of a streamlined semicylindrical model are used for the purpose of investigation. The impact is carried out by organizing local gas discharge regions when applying a magnetic field transverse to gas discharge currents. It has been shown that by changing the local region of application, the intensity and the direction of the gas discharge currents, it is possible to change the intensity and direction of the ponderomotive force acting on the gas flow during MHD interaction. The ponderomotive force control allows for acting locally on the shape and position of shock waves, the speed and direction of the flow, and the increase or reduction of pressure near the surface of the streamlined body. The experiments were carried out on a gas dynamic setup based on a shock tube in a gas dynamic path, capable of creating supersonic flows in a wide range of Mach numbers at M = 4–7. There was a possibility of organizing the electric and pulsed magnetic fields with an intensity of up to 1.5 T. The given experimental Schlieren flow patterns and the analysis of the obtained data demonstrate the MHD effect on: the change in the angle of inclination of the attached shocks, both into increase and decrease; the bow shock wave approaching the body or the removal from it; and the change in the aerodynamic drag and lift force of the streamlined bodies.

Simultaneous Estimation of Gas Adsorption Equilibria and Kinetics of Individual Shaped Adsorbents.

Shaped adsorbents (e.g., pellets, extrudates) are typically employed in several gas separation and sensing applications. The performance of these adsorbents is dictated by two key factors, their adsorption equilibrium capacity and kinetics. Often, adsorption equilibrium and textural properties are reported for materials. Adsorption kinetics are seldom presented due to the challenges associated with measuring them. The overarching goal of this work is to develop an approach to characterize the adsorption properties of individual shaped adsorbents with less than 100 mg of material. To this aim, we have developed an experimental dynamic sorption setup and complemented it with mathematical models, to describe the mass transport in the system. We embed these models into a derivative-free optimizer to predict model parameters for adsorption equilibrium and kinetics. We evaluate and independently validate the performance of our approach on three adsorbents that exhibit differences in their chemistry, synthesis, formulation, and textural properties. Further, we test the robustness of our mathematical framework using a digital twin. We show that the framework can rapidly (i.e., in a few hours) and quantitatively characterize adsorption properties at a milligram scale, making it suitable for the screening of novel porous materials.