scholarly journals Pulsed IR Heating of Thermoplastic Sheets for Thermoforming Applications

2021 ◽  
Vol 36 (4) ◽  
pp. 388-397
Author(s):  
B. Buffel ◽  
K. Leeman ◽  
F. Desplentere
Keyword(s):  
Temperature Difference ◽  
Added Value ◽  
Heating Process ◽  
Time Interval ◽  
Heater Element ◽  
Slowing Down ◽  
Pulsed Heating ◽  
Current State ◽  
Ir Heating ◽  
Explicit Finite Difference

Abstract This study presents the pulsed heating strategy as an advancement of the current state of the art in industry towards the theoretically fastest method of heating a thermoplastic sheet. Experimental temperature measurements are combined with an explicit finite difference numerical model to describe the pulsed heating method and indicate its added value in IR heating of thermoplastic sheets. Different process settings are evaluated and indicate the effect of the applied heat flux and the time interval tOFF during pulsed heating. When switched off, the residual heating of the heater elements is able to partially compensate for the convective heat losses at the surface of the sheet. This results in a more uniform temperature distribution through thickness without slowing down the overall heating process. The study shows that this effect is lost when the time interval in which the heater element is switched off, increases. Applying pulsed heating opens up a large processing window to control the through-thickness temperature difference. When the total amount of applied thermal energy is taken into account, pulsed heating is able to increase the overall heating rate and simultaneously keep the temperature difference through thickness limited.

scholarly journals Detecting hotspots of atmosphere–vegetation interaction via slowing down – Part 1: A stochastic approach

2013 ◽  
Vol 4 (1) ◽  
pp. 63-78 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
K. Fraedrich
Keyword(s):  
Climate Models ◽  
Stochastic Approach ◽  
General Context ◽  
Grid Cells ◽  
Climate System Model ◽  
Local Loss ◽  
Slowing Down ◽  
Current State ◽  
Long Time ◽  
Sudden Transition

Abstract. An analysis of so-called early warning signals (EWS) is proposed to identify the spatial origin of a sudden transition that results from a loss in stability of a current state. EWS, such as rising variance and autocorrelation, can be indicators of an increased relaxation time (slowing down). One particular problem of EWS-based predictions is the requirement of sufficiently long time series. Spatial EWS have been suggested to alleviate this problem by combining different observations from the same time. However, the benefit of EWS has only been shown in idealised systems of predefined spatial extent. In a more general context like a complex climate system model, the critical subsystem that exhibits a loss in stability (hotspot) and the critical mode of the transition may be unknown. In this study we document this problem with a simple stochastic model of atmosphere–vegetation interaction where EWS at individual grid cells are not always detectable before a vegetation collapse as the local loss in stability can be small. However, we suggest that EWS can be applied as a diagnostic tool to find the hotspot of a sudden transition and to distinguish this hotspot from regions experiencing an induced tipping. For this purpose we present a scheme which identifies a hotspot as a certain combination of grid cells which maximise an EWS. The method can provide information on the causality of sudden transitions and may help to improve the knowledge on the susceptibility of climate models and other systems.

scholarly journals Battlefield praxis: The alliance of realism and constructivism and the “fall” of liberal internationalism

2017 ◽  
Vol 69 (2-3) ◽  
pp. 262-282
Author(s):  
Vladimir Ajzenhamer
Keyword(s):  
Foreign Policy ◽  
International Relations ◽  
The United States ◽  
Precise Determination ◽  
Theory And Practice ◽  
Time Interval ◽  
Liberal Internationalism ◽  
Current State ◽  
Disciplinary Field ◽  
Political Praxis

The Great Debates are an important stage in the development of International Relations (IR) as a science. However, the ?exactness? of its chronology and content, as well as the precise determination of the actors and results, is questionable on several grounds. Therefore, relying on this, often contradictory, interpretations of the outcome of the Great Debates, little can be said about the current state of the mentioned theoretical dialogue. Today, IR scholars mostly discuss abandoning the idea of macro theory and the pluralistic silence in which medium-scale theories resonate in peace. However, this "diagnosis" still does not give us an answer to the question of who really won the fight of so-called big theories, or which theoretical paradigm today has the greatest influence within the disciplinary field? Applying the idea of reflexivity between the theory of international relations and the practice of foreign policy, the author of this paper rejects the restrictions of the mythos of the discipline (at the center of which is the myth of the Great Debates) and turns to the analysis of international political praxis as an instrument for the identification of the mentioned theoretical impact. At the center of the analysis are the foreign policy principles of the United States, which the author reviews in a hundred-year time interval, in particular emphasizing the doctrine of Wilsonianism and the principles of foreign policy advocated by the current US President Donald Tramp. Facing Wilsonianism and Trampism (determining, in turn, the latter as a realistic-constructivist Anti-Wilsonian coalition), the author offers his view of the current state of paradigmatic ?clashes? in the theory and practice of international relations.

Simulation and Optimization of Temperature Field of Tank Cover with Super Large Diameter during the Creep Aging Forming Process

2021 ◽  
Vol 315 ◽  
pp. 3-9
Author(s):  
Yuan Gao ◽  
Li Hua Zhan ◽  
Hai Long Liao ◽  
Xue Ying Chen ◽  
Ming Hui Huang
Keyword(s):  
Temperature Field ◽  
Field Distribution ◽  
Temperature Difference ◽  
Single Stage ◽  
Maximum Temperature ◽  
Heating Process ◽  
Temperature Field Distribution ◽  
Two Stage ◽  
Maximum Temperature Difference ◽  
Forming Accuracy

The uniformity of temperature field distribution in creep aging process is very important to the forming accuracy of components. In this paper, the temperature field distribution of 2219 aluminum alloy tank cover during aging forming is simulated by using the finite element software FLUENT, and a two-stage heating process is proposed to reduce the temperature field distribution heterogeneity. The results show that the temperature difference of the tank cover is large in the single-stage heating process, and the maximum temperature difference is above 27°C,which seriously affects the forming accuracy of the tank cover. With two-stage heating process, the temperature difference in the first stage has almost no direct impact on the forming accuracy of the top cover. In the second stage, the temperature difference of the tank cover is controlled within 10°C, compared with the single-stage heating, the maximum temperature difference is reduced by more than 17°C. The two-stage heating effectively reduces the heterogeneity of the temperature field of the top cover. The research provides technical support for the precise thermal mechanical coupling of large-scale creep aging forming components.

The Numerical Analysis of Temperature Field During Moveable Induction Heating of Steel Plate

2012 ◽  
Vol 28 (02) ◽  
pp. 73-81
Author(s):  
Xue-biao Zhang ◽  
Yu-long Yang ◽  
Yu-jun Liu
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Numerical Model ◽  
Induction Heating ◽  
Temperature Difference ◽  
Steel Plate ◽  
Heating Process ◽  
Quasi Steady State ◽  
Initial State ◽  
Plate Temperature

In shipyards, hull curved plate formation is an important stage with respect to productivity and accuracy control of curved plates. Because the power and its distribution of induction heat source are easier to control and reproduce, induction heating is expected to be applied in the line heating process. This paper studies the moveable induction heating process of steel plate and develops a numerical model of electromagneticthermal coupling analysis and the numerical results consistent with the experimental results. The numerical model is used to analyze the temperature changing rules and the influences on plate temperature field of heating speed of moveable induction heating of steel plate, and the following conclusions are drawn. First, the process of moveable induction heating of steel plate can be divided into three phases of initial state, quasi-steady state, and end state. The temperature difference between the top and bottom surfaces of the steel plate at the initial state is the biggest; it remains unchanged at the quasi-steady state and it is the smallest at the end state. Second, obvious end effect occurs when the edges of the steel plate are heated by the inductor, which causes a decrease in temperature difference between the top and bottom surfaces of the steel plate that is unfavorable for formation of pillow shape plates. Third, with the increase of heating speed, the temperature difference between the top and bottom surfaces of the steel plate increases gradually.

The Resource Efficiency Assessment Technique for the Foundry Production

2014 ◽  
Vol 880 ◽  
pp. 141-145 ◽  
Author(s):  
Igor G. Vidayev ◽  
Nikita Martyushev ◽  
Aleksander S. Ivashutenko ◽  
Anna M. Bogdan
Keyword(s):  
Resource Efficiency ◽  
Added Value ◽  
Assessment Technique ◽  
Efficiency Assessment ◽  
Current State ◽  
Different Types

The short analysis of the assessment opportunities is presented for the resource efficiency in various industries and particularly in the foundry production. The developed algorithm of carrying out such assessment is presented. It is shown that such algorithm consists of five steps. They are the formation of the evaluating team, the choice of the technology or a product, the analysis of the chain creation of the added value for a technology or a product, the assessment of the current state of the technology or a product, developing the recommendations for the improvement of the efficiency of resources use. This article describes in detail the works, which need to be carried out at each stage of evaluating the resource efficiency. The evaluating map and the criteria are developed for comparing different types of the foundry technologies as well as the map for assessing the current state of the foundry technology. The result of the accomplished assessment with the described algorithm is the developed recommendations on the use of the enterprise resources.

Investigation of current state of pre-consumer textile waste generated at Lithuanian enterprises

2017 ◽  
Vol 29 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Vaida Dobilaite ◽  
Gene Mileriene ◽  
Milda Juciene ◽  
Virginija Saceviciene
Keyword(s):  
Statistical Data ◽  
Added Value ◽  
Waste Generation ◽  
Content Type ◽  
Textile Waste ◽  
Textile Fibres ◽  
Current State ◽  
Not Otherwise Specified ◽  
Business Cases ◽  
Materials Used

Purpose Production and consumption of textile garments contribute significantly to environment problems. The purpose of this paper is to perform the evaluation of textile waste generated at Lithuanian clothing enterprises based on statistical data analysis and business cases studies. Design/methodology/approach For the evaluation of real situation of waste generation in companies, an original methodology was developed and used during investigation. In order to get an overall view, statistical data of waste generation and management in Lithuania were also analysed. Waste accounting covered data such as wastes from unprocessed textile fibres and wastes from processed textile fibres and textiles (not otherwise specified). Findings The investigation showed that the amount of cutting waste reaches 20-25 per cent of the total quantity of materials used for production. It was found that the waste is not sorted in Lithuanian clothing enterprises and is disposed in landfills in most cases, notwithstanding the positive tendencies of recycling of waste that were observed during past year. However, a practical recycling strategy and broader perception of developing products with greater added value from waste are missing in Lithuania. Originality/value In this research, a simple methodology was developed for determining the quantity of the textile waste generated by enterprises, the introduction of which would allow us to expect better results in waste accounting and management. The results of investigation are useful to gain in-depth understanding of waste generation in various countries.

scholarly journals ФІНАНСОВЕ ЗАБЕЗПЕЧЕННЯ СТИМУЛЮВАННЯ РОЗВИТКУ ТРУДОВОГО ПОТЕНЦІАЛУ В УМОВАХ АКТИВІЗАЦІЇ МІГРАЦІЙНИХ ПРОЦЕСІВ

2020 ◽  
pp. 229-237
Author(s):  
Liudmyla Mekshun ◽  
Maksym Zabashtanskyi
Keyword(s):  
National Economy ◽  
Financial Support ◽  
World Market ◽  
Added Value ◽  
High Tech ◽  
Innovative Product ◽  
Current State ◽  
Fixed Assets ◽  
The World ◽  
Labor Potential

The article analyzes the current state and prospects of financial development of labor potential in Ukraine. The comparative analysis of financial support of labor stimulation in the leading countries of the world is carried out, the factors of stimulating and limiting influence on a condition of labor potential of the country are grouped. It is determined that the key problems hindering the development of labor potential in the country are the low level of development of the national economy, associated with a significant backlog of technological capabilities, moral and physical depreciation of fixed assets, the inability to create an innovative product with high added value. It is substantiated that in order to develop the national economy, the key condition is the creation of high-tech production that can ensure the competitiveness of its own products on the world market, which can be done only with adequate financial support to stimulate labor potential. It is proved that adequate financial support for labor incentives should be a key condition for the generation and preservation of labor potential necessary for the effective functioning of the national economy.

scholarly journals Genomic Prediction of Antimicrobial Resistance: Ready or Not, Here It Comes!

2020 ◽  
Vol 66 (10) ◽  
pp. 1278-1289
Author(s):  
Eric M Ransom ◽  
Robert F Potter ◽  
Gautam Dantas ◽  
Carey-Ann D Burnham
Keyword(s):  
Antimicrobial Resistance ◽  
Diagnostic Testing ◽  
Turnaround Time ◽  
Added Value ◽  
Clinical Settings ◽  
Bioinformatic Pipeline ◽  
Current State ◽  
Resistance Prediction ◽  
Diagnostic Microbiology ◽  
Next Generation Sequencing Ngs

Abstract Background Next-generation sequencing (NGS) technologies are being used to predict antimicrobial resistance. The field is evolving rapidly and transitioning out of the research setting into clinical use. Clinical laboratories are evaluating the accuracy and utility of genomic resistance prediction, including methods for NGS, downstream bioinformatic pipeline components, and the clinical settings in which this type of testing should be offered. Content We describe genomic sequencing as it pertains to predicting antimicrobial resistance in clinical isolates and samples. We elaborate on current methodologies and workflows to perform this testing and summarize the current state of genomic resistance prediction in clinical settings. To highlight this aspect, we include 3 medically relevant microorganism exemplars: Mycobacterium tuberculosis, Staphylococcus aureus, and Neisseria gonorrhoeae. Last, we discuss the future of genomic-based resistance detection in clinical microbiology laboratories. Summary Antimicrobial resistance prediction by genomic approaches is in its infancy for routine patient care. Genomic approaches have already added value to the current diagnostic testing landscape in specific circumstances and will play an increasingly important role in diagnostic microbiology. Future advancements will shorten turnaround time, reduce costs, and improve our analysis and interpretation of clinically actionable results.

scholarly journals Molecular imaging in nuclear cardiology: Pathways to individual precision medicine

2020 ◽  
Vol 27 (6) ◽  
pp. 2195-2201
Author(s):  
A. Glasenapp ◽  
A. Hess ◽  
J. T. Thackeray
Keyword(s):  
Molecular Imaging ◽  
Nuclear Cardiology ◽  
Precision Medicine ◽  
Added Value ◽  
Response To Treatment ◽  
Non Invasive ◽  
Current State ◽  
Challenges And Opportunities ◽  
Progression Of Disease ◽  
Careful Investigation

AbstractGrowth of molecular imaging bears potential to transform nuclear cardiology from a primarily diagnostic method to a precision medicine tool. Molecular targets amenable for imaging and therapeutic intervention are particularly promising to facilitate risk stratification, patient selection and exquisite guidance of novel therapies, and interrogation of systems-based interorgan communication. Non-invasive visualization of pathobiology provides valuable insights into the progression of disease and response to treatment. Specifically, inflammation, fibrosis, and neurohormonal signaling, central to the progression of cardiovascular disease and emerging therapeutic strategies, have been investigated by molecular imaging. As the number of radioligands grows, careful investigation of the binding properties and added-value of imaging should be prioritized to identify high-potential probes and facilitate translation to clinical applications. In this review, we discuss the current state of molecular imaging in cardiovascular medicine, and the challenges and opportunities ahead for cardiovascular molecular imaging to navigate the path from diagnosis to prognosis to personalized medicine.

scholarly journals Lignocellulosic bio-refinery downstream products in future packaging applications

2020 ◽  
Author(s):  
Igor Karlovits ◽  
Keyword(s):  
Animal Feed ◽  
State Of The Art ◽  
Paper Industry ◽  
Building Blocks ◽  
Added Value ◽  
Current State ◽  
Lignocellulosic Feedstock ◽  
Food Applications ◽  
Protective Packaging ◽  
Different Sources

The concept of efficient utilisation of renewable bio-based materials (biomass feedstock) is the driving force in the green transformation to a more sustainable and circular society. Biorefineries or biochemical platforms convert and utilise different sources of biomass into fuels and other beneficial derivates like fibres and other bio-based chemicals. These can be used as building blocks for many potentially useful applications. In this review, we shall describe the current state of the art and trends in the conversion of lignocellulosic feedstock into materials which can be primarily used in packaging applications. The three main constituents (cellulose, hemicellulose and lignin) are being re-engineered into new products with higher added value. The main goal of all these downstream products is that they do not compete with animal feed and food applications. The main downstream products of different kind of transformations are different natural fibres which can be further processed into micro or nano fibrillated state and used for a broad application of fields from ink, adhesive and packaging materials. Also, fibres and its derivates can be bonded successfully into bio-composites or fibre-based foams applications for the protective packaging applications. Hemicellulose, as a second most abundant component, has been researched for applications in adhesives and paper and paperboard coatings. Lignin which is currently utilised as an energy source for the paper industry, has been recently actively researched. Lignin-based biopolymers have a potential to be used in many different applications from additives in the barrier coatings on the packaging to active packaging and even as lignin-based foams. All these applications are currently in the development stages and cover niche market segments, but are expected to grow and to be used in future markets.

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