scholarly journals Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

2017 ◽  
Author(s):  
Andrew J.S. Mcgonigle ◽  
Tom D. Pering ◽  
Thomas C. Wilkes ◽  
Giancarlo Tamburello ◽  
Roberto D’Aleo ◽  
...  
Keyword(s):  
Gas Flow ◽  
Dynamic Models ◽  
Fluid Dynamic ◽  
Future Research ◽  
New Paradigm ◽  
Volcanic Gas ◽  
Volcanic Source ◽  
Smartphone Sensors ◽  
Activity Types ◽  
Lava Lakes

Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes, than achievable hitherto. To date this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at ≈ 1 Hz expediting more holistic investigations of volcanic source-process behaviour. Secondly, there has been the combination of surface observations of gas release, with fluid dynamic models (numerical, mathematical and laboratory) for gas flow in conduits, in attempts to link subterranean driving flow processes to surface activity types. There has also been considerable research and development concerning the technique itself, covering error analysis and most recently adaptation of smartphone sensors for this application, to deliver gas fluxes at a significantly lower instrumental price point than possible previously. At this decadal juncture in the application of UV imaging in volcanology, this article provides an overview of what has been achieved to date as well as a forward look to potential future research directions, in particular covering the first use of UV cameras to generate volcanic gas composition ratio imagery.

Fiber energy efficiency Part I: Extended entropy model

2014 ◽  
Vol 29 (2) ◽  
pp. 322-331 ◽  
Author(s):  
Anders Karlström ◽  
Karin Eriksson
Keyword(s):  
Energy Efficiency ◽  
Temperature Profile ◽  
Dynamic Models ◽  
Fluid Dynamic ◽  
Multiscale Model ◽  
Process Conditions ◽  
Entropy Model ◽  
Refining Zone ◽  
Energy Balances ◽  
Flat Zone

Abstract This is the first in a series of papers presenting the development of a comprehensive multiscale model with focus on fiber energy efficiency in thermo mechanical pulp processes. The fiber energy efficiency is related to the defibration and fibrillation work obtained when fibers and fiber bundles interact with the refining bars. The fiber energy efficiency differs from the total refining energy efficiency which includes the thermodynamical work as well. Extracting defibration and fibrillation work along the radius in the refining zone gives information valuable for fiber development studies.Models for this process must handle physical variables as well as machine specific parameters at different scales. To span the material and energy balances, spatial measurements from the refining zone must be available. In this paper, measurements of temperature profile and plate gaps from a full-scale CD-refiner are considered as model inputs together with a number of process variables. This enables the distributed consistency in the refining zone as well as the split of the total work between the flat zone and the CD-zone to be derived. As the temperature profile and the plate gap are available in the flat zone and the CD-zone at different process conditions it is also shown that the distributed pulp dynamic viscosity can be obtained. This is normally unknown in refining processes but certainly useful for all fluid dynamic models describing the bar-to-fiber interactions. Finally, it is shown that the inclusion of the machine parameters will be vital to get good estimates of the refining conditions and especially the split between the thermodynamical work and the defibration/fibrillation work.

Towards real-time fire data synthesis using numerical simulations

2021 ◽  
pp. 073490412199344
Author(s):  
Wolfram Jahn ◽  
Frane Sazunic ◽  
Carlos Sing-Long
Keyword(s):  
Real Time ◽  
Computational Fluid Dynamic ◽  
Dynamic Models ◽  
Fluid Dynamic ◽  
Near Field ◽  
Computing Time ◽  
Temperature Correction ◽  
Dynamic Simulations ◽  
Conservation Of Energy ◽  
Fire Scenarios

Synthesising data from fire scenarios using fire simulations requires iterative running of these simulations. For real-time synthesising, faster-than-real-time simulations are thus necessary. In this article, different model types are assessed according to their complexity to determine the trade-off between the accuracy of the output and the required computing time. A threshold grid size for real-time computational fluid dynamic simulations is identified, and the implications of simplifying existing field fire models by turning off sub-models are assessed. In addition, a temperature correction for two zone models based on the conservation of energy of the hot layer is introduced, to account for spatial variations of temperature in the near field of the fire. The main conclusions are that real-time fire simulations with spatial resolution are possible and that it is not necessary to solve all fine-scale physics to reproduce temperature measurements accurately. There remains, however, a gap in performance between computational fluid dynamic models and zone models that must be explored to achieve faster-than-real-time fire simulations.

scholarly journals Multiphasic Study of Fluid-Dynamics and the Thermal Behavior of a Steel Ladle during Bottom Gas Injection Using the Eulerian Model

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1082
Author(s):  
Antonio Urióstegui-Hernández ◽  
Pedro Garnica-González ◽  
José Ángel Ramos-Banderas ◽  
Constantin Alberto Hernández-Bocanegra ◽  
Gildardo Solorio-Díaz
Keyword(s):  
Heat Exchange ◽  
Thermal Behavior ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Steel Slag ◽  
Scale Model ◽  
Discrete Ordinates ◽  
Transfer Model ◽  
Steel Ladle ◽  
Physical Scale

In this work, the fluid dynamic and thermal behavior of steel was analyzed during argon gas stirring in a 140-t refining ladle. The Eulerian multiphase mathematical model was used in conjunction with the discrete ordinates (DO) thermal radiation model in a steel-slag-argon system. The model was validated by particle image velocimetry (PIV) and the analysis of the opening of the oil layer in a physical scale model. The effect of Al2O3 and Mg-C as a refractory in the walls was studied, and the Ranz-Marshall and Tomiyama models were compared to determine the heat exchange coefficient. The results indicated that there were no significant differences between these heat exchange models; likewise, the radiation heat transfer model adequately simulated the thermal behavior according to plant measurements, finding a thermal homogenization time of the steel of 2.5 min for a gas flow of 0.45 Nm3·min−1. Finally, both types of refractory kept the temperature of the steel within the ranges recommended in the plant; however, the use of Al2O3 had better heat retention, which would favor refining operations.

Hyperbolic versus Parabolic Asymptotics in Kinetic Theory toward Fluid Dynamic Models

2013 ◽  
Vol 73 (4) ◽  
pp. 1327-1346 ◽  
Author(s):  
Abdelghani Bellouquid ◽  
Juan Calvo ◽  
Juan Nieto ◽  
Juan Soler
Keyword(s):  
Kinetic Theory ◽  
Dynamic Models ◽  
Fluid Dynamic

Modeling of Flow Fields of Different Delivery Chamfers in Spray Forming Process

2014 ◽  
Vol 789 ◽  
pp. 554-559
Author(s):  
Yang Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Wen Yong Xu
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Metal Flow ◽  
Spray Forming ◽  
Operating Pressure ◽  
Delivery Tube ◽  
Forming Process ◽  
Atomization Process ◽  
Sharp Point

The computational fluid dynamic (CFD) software was used to calculate the velocity field in atomization chamber of spray forming equipment. The relationship between melt flow rates, gas aspiration of the atomizer and operating pressure are complex, and the above mentioned parameters are closely related to the atomization process. The influences of different delivery chamfers on gas flow field, which is determined by atomizer structure, were analyzed. Using K-epsilon model with a symmetrical domain, the gas dynamic of different delivery chamfer conditions were investigated. The results indicate that the sharp point of delivery tube causes detachment of flow field, and 56°, 45° and 34° chamfer conditions have same diffusion angle. Gas was aspirated from delivery tube when chamfer was 0°, which is beneficial to liquid metal flow in atomization process.

scholarly journals Alpha-1 antitrypsin deficiency as a common treatable mechanism in chronic respiratory disorders and for conditions different from pulmonary emphysema? A commentary on the new European Respiratory Society statement

2018 ◽  
Vol 13 ◽  
Author(s):  
Stefano Aliberti ◽  
Andrea Gramegna ◽  
Marco Confalonieri ◽  
Angelo Corsico ◽  
Luca Richeldi ◽  
...  
Keyword(s):  
Lung Disease ◽  
Pulmonary Emphysema ◽  
Future Research ◽  
Common Mechanism ◽  
Main Body ◽  
New Paradigm ◽  
European Respiratory Society ◽  
Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin

Background: The European Respiratory Society recently published an important statement reviewing available evidence on diagnosis and treatment of lung disease associated to alpha-1 antitrypsin deficiency (AATD). Several issues on this topic still remain unresolved and subject of interpretation according to different standard procedures and healthcare systems worldwide. The purpose of this commentary is to offer a critical contribution to most of these controversial issues in light of an Italian perspective for the management of this disease. Main body: The clinical spectrum of AATD lung disease might include different manifestations and the traditional paradigm of a younger emphysematous patient has been revealing insufficient. Targeting with appropriate testing only COPD patients might be considered a limited approach leading to underestimation of the real prevalence of the disease. Several reports have suggested the association between AATD and other chronic respiratory conditions, as asthma and bronchiectasis. A deeper evaluation of clinical, radiological, microbiological and functional variables is, therefore, needed in order to investigate different phenotypes in AATD patients. In addition, a new line of translational research in AATD might focus on the development of personalized therapeutic regimens taking into account the patient clinical profile and needs. Conclusions: Over the past years, AATD has been interpreted as a common mechanism of inflammatory disequilibrium and tissue damage across different conditions. Future research is gradually pointing toward this new paradigm by expanding the evidence of the role of AAT as a potent immunomodulatory and anti-inflammatory drug in conditions different from pulmonary emphysema.

scholarly journals CubeSat Communications: Recent Advances and Future Challenges

2020 ◽  
Author(s):  
Nasir Saeed ◽  
Ahmed Elzanaty ◽  
Heba Almorad ◽  
Hayssam Dahrouj ◽  
Tareq Y. Al-Naffouri ◽  
...  
Keyword(s):  
Channel Modeling ◽  
Future Research ◽  
New Paradigm ◽  
Earth Remote Sensing ◽  
Research Directions ◽  
Space Industry ◽  
Recent Advances ◽  
Wide Range ◽  
Future Challenges ◽  
Future Research Directions

<pre><pre>Given the increasing number of space-related applications, research in the emerging space industry is becoming more and more attractive. One compelling area of current space research is the design of miniaturized satellites, known as CubeSats, which are enticing because of their numerous applications and low design-and-deployment cost. </pre><pre>The new paradigm of connected space through CubeSats makes possible a wide range of applications, such as Earth remote sensing, space exploration, and rural connectivity.</pre><pre>CubeSats further provide a complementary connectivity solution to the pervasive Internet of Things (IoT) networks, leading to a globally connected cyber-physical system.</pre><pre>This paper presents a holistic overview of various aspects of CubeSat missions and provides a thorough review of the topic from both academic and industrial perspectives.</pre><pre>We further present recent advances in the area of CubeSat communications, with an emphasis on constellation-and-coverage issues, channel modeling, modulation and coding, and networking.</pre><pre>Finally, we identify several future research directions for CubeSat communications, including Internet of space things, low-power long-range networks, and machine learning for CubeSat resource allocation.</pre></pre>

scholarly journals AI-Enabled Sensing and Decision-Making for IoT Systems

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hao Qinxia ◽  
Shah Nazir ◽  
Ma Li ◽  
Habib Ullah ◽  
Wang Lianlian ◽  
...  
Keyword(s):  
Decision Making ◽  
Real Life ◽  
Research Community ◽  
Smart Sensors ◽  
Future Research ◽  
New Paradigm ◽  
Exclusion Criteria ◽  
Intelligent Devices ◽  
Research Questions

The influential stage of Internet of Things (IoT) has reformed all fields of life in general but specifically with the emergence of artificial intelligence (AI) has drawn the attention of researchers into a new paradigm of life standard. This revolution has been accepted around the globe for making life easier with the use of intelligent devices such as smart sensors, actuators, and many other devices. AI-enabled devices are more intelligent and capable of doing a specific task which saves a lot of resources and time. Different approaches are available in the existing literature to tackle diverse issues of real life based on AI and IoT systems. The role of decision-making has its own importance in the AI-enabled and IoT systems. In-depth knowledge of the existing literature is dire need of the research community to summarize the literature in effective way by which practitioners and researchers can benefit from the prevailing proofs and suggest new solutions for solving a particular problem of AI-enabled sensing and decision-making for the IoT system. To facilitate research community, the proposed study presents a systematic literature review of the existing literature, organizes the evidences in a systematic way, and then analyzes it for future research. The study reported the literature of the last 5 years based on the research questions, inclusion and exclusion criteria, and quality assessment of the selected study. Finally, derivations are drawn from the included paper for future research.

scholarly journals The gas flow pattern through small size Resistive Plate Chambers with 2 mm gap

2021 ◽  
Vol 16 (11) ◽  
pp. P11022
Author(s):  
Y. Pezeshkian ◽  
A. Kiyoumarsioskouei ◽  
M. Ahmadpouri ◽  
G. Ghorbani
Keyword(s):  
Gas Flow ◽  
Fluid Dynamic ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
Dynamic Methods ◽  
Gas System ◽  
Gas Molecules ◽  
Simulation Results ◽  
Resistive Plate Chambers ◽  
The Difference

Abstract A prototype of a single-gap glass Resistive Plate Chamber (RPC) is constructed by the authors. To find the requirements for better operation of the detector's gas system, we have simulated the flow of the Argon gas through the detector by using computational fluid dynamic methods. Simulations show that the pressure inside the chamber linearly depends on the gas flow rate and the chamber's output hose length. The simulation results were compatible with experiments. We have found that the pressure-driven speed of the gas molecules is two orders of magnitude larger in the inlet and outlet regions than the blocked corners of a 14 × 14 cm2 chamber, and most likely the difference in speed is higher for larger detectors and different geometries.

scholarly journals Modeling the Influence of Information Systems on Sustainable Business Performance and Competitiveness

2021 ◽  
Vol 13 (17) ◽  
pp. 9619
Author(s):  
Natasa Djalic ◽  
Milan Nikolic ◽  
Mihalj Bakator ◽  
Zivko Erceg
Keyword(s):  
Sustainable Development ◽  
Information Systems ◽  
Business Performance ◽  
Transition Economy ◽  
Industrial Revolution ◽  
Business Environment ◽  
Future Research ◽  
New Paradigm ◽  
Sustainable Business ◽  
Challenging Environment

The necessity for sustainable development, the coronavirus pandemic, and conducting business within the frameworks of the fourth industrial revolution—Industry 4.0 create a challenging environment where enterprises have difficulties to achieve and maintain competitiveness. Information is becoming a core construct when it comes to conducting business in the modern, globalized business environment. In this paper, the influence of information systems (IS) on sustainable business performance and competitiveness is analyzed. Additionally, the influence of human resource management (HRM) and decision making (DM) on sustainable business performance and competitiveness, as two crucial constructs in the new paradigm of conducting business, are addressed. The relations are discussed from the aspect of sustainable development and future post-pandemic business trends. The main goal is to determine the relations between the noted constructs in a transitional setting. In sum, 184 manufacturing enterprises from Republika Srpska were surveyed via a structured survey, where the focus was on quantifying and modeling the influence of IS, HRM, and DM on sustainable business performance. The results indicate that IS, HRM, DM can affect business performance in a transitional economic setting. This approach is novel, as the existing body of literature does not address all the noted influencing factors on sustainable business performance and competitiveness in a transition economy. Hence, this paper significantly contributes to the existing body of literature and provides a solid basis for future research in this domain.

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