The Mathematical Modelling of Transport Phenomena in Non-Transferred Plasma Systems: Accomplishments and Unresolved Problems

1987 ◽  
Vol 98 ◽  
Author(s):  
A. H. Dilawari ◽  
J. Szekely
Keyword(s):  
Transport Phenomena ◽  
Computational Fluid Mechanics ◽  
Plasma Arc ◽  
Critical Comparison ◽  
System A ◽  
Turbulent Transition ◽  
Standard Application ◽  
Inlet Conditions ◽  
System Properties ◽  
Future Work

ABSTRACTAn overview is presented of transport phenomena in non-transferred plasma arc systems. It has been shown that while the modelling of these systems involves the standard application of computational fluid mechanics techniques, numerous pitfalls may be encountered in practice. A detailed discussion of these is presented, with emphasis on the torch inlet conditions, the effect of swirl, the temperature dependence of the system properties and the laminar-turbulent transition in the system. A critical comparison is presented with experimental measurements, and the necessary future work is also outlined.

Brain angiotensin system: a new promise in the management of epilepsy?

2021 ◽  
Vol 135 (6) ◽  
pp. 725-730
Author(s):  
Alberto Javier Ramos
Keyword(s):  
Therapeutic Potential ◽  
Renin Angiotensin System ◽  
B Cell Lymphoma ◽  
Ang Ii ◽  
Angiotensin System ◽  
Beneficial Effects ◽  
System A ◽  
Pilocarpine Model ◽  
Animal Models Of Epilepsy ◽  
Future Work

Abstract Epilepsy is a highly prevalent neurological disease and anti-epileptic drugs (AED) are almost the unique clinical treatment option. A disbalanced brain renin–angiotensin system (RAS) has been proposed in epilepsy and several reports have shown that angiotensin II (Ang II) receptor-1 (ATR1) activation is pro-inflammatory and pro-epileptogenic. In agreement, ATR1 blockage with the repurposed drug losartan has shown benefits in animal models of epilepsy. Processing of Ang II by ACE2 enzyme renders Ang-(1-7), a metabolite that activates the mitochondrial assembly (Mas) receptor (MasR) pathway. MasR activation presents beneficial effects, facilitating vasodilatation, increasing anti-inflammatory and antioxidative responses. In a recent paper published in Clinical Science, Gomes and colleagues (Clin. Sci. (Lond.) (2020) 134, 2263–2277) performed intracerebroventricular (icv) infusion of Ang-(1-7) in animals subjected to the pilocarpine model of epilepsy, starting after the first spontaneous motor seizure (SMS). They showed that this approach reduced the frequency of SMS, restored animal anxiety, increased exploration, and augmented the hippocampal expression of protective catalase enzyme and antiapoptotic protein B-cell lymphoma 2 (Bcl-2). Interestingly, but surprisingly, Gomes and colleagues showed that MasR expression and mTor activity were reduced in the hippocampus of the epileptic Ang-(1-7) treated animals. These results show that Ang-(1-7) administration could represent a new avenue for developing strategies for the management of epilepsy in clinical settings. However, future work is necessary to evaluate the levels of RAS metabolites and the activity of key enzymes in these experimental interventions to completely understand the therapeutic potential of the brain RAS manipulation in epilepsy.

scholarly journals Measuring Maximum Head Circumference Within the Picture Archiving and Communication System: A Fully Automatic Approach

2021 ◽  
Vol 9 ◽  
Author(s):  
Fernando Yepes-Calderon ◽  
Frisca Wihardja ◽  
Andrea Sloan ◽  
Janet Kim ◽  
Marvin D. Nelson ◽  
...  
Keyword(s):  
Head Circumference ◽  
Retrospective Chart Review ◽  
Radiology Report ◽  
3D Objects ◽  
System A ◽  
Picture Archiving ◽  
Standard Application ◽  
Ring Structures ◽  
3D Printed ◽  
Picture Archiving And Communication

This study describes an automatic technique to accurately determine the maximum head circumference (MHC) measurement from MRI studies within the Picture Archiving and Communications System, and can automatically add this measurement to the final radiology report. Participants were selected through a retrospective chart review of patients referred to the neurosurgery clinic. Forty-nine pediatric patients with ages ranging from 5 months to 11 years were included in the study. We created 14 printed ring structures to mirror the head circumference values at various ages along the x-axis of the Nellhaus chart. The 3D-printed structures were used to create MRI phantoms. Analytical obtainment of circumference values from the 3D objects and phantom images allowed for a fair estimation and correction of errors on the image-based-measuring instrument. Then, standard manual MHC measurements were performed and compared to values obtained from the patients' MRI T1 images using the tuned instrument proposed in this document. A T-test revealed no statistical difference between the manual assessments and the ones obtained by the automation p = 0.357, α = 0.05. This automatic application augments the more error-prone manual MHC measurement, and can add a numerical value to the final radiology report as a standard application.

Influence of Plasma Torch Nozzle Design on Plasma Arc Analyzed with Finite Element Method

2015 ◽  
Vol 1095 ◽  
pp. 751-755
Author(s):  
Hai Yan Wang ◽  
Yi Jiang ◽  
Yuan Peng Xia ◽  
Yun Li Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Plasma Torch ◽  
Plasma Arc ◽  
Direction Parallel ◽  
System A ◽  
Welding Torch ◽  
Large Pressure ◽  
Generating System ◽  
Element Method

Plasma torch is one of the most important parts for plasma arc generating system. A design of orifices in a nozzle would decide the properties of plasma arc. However, mechanisms of orifice to plasma arc are seldom discussed. In this paper, the plasma arc with two assistant orifices were analyzed by finite element method. It was concluded that the plasma arc would be further compressed in the direction parallel to two assistant orifices, but expand perpendicular to assistant orifices. Through the constriction of two assistant orifices, the shape of the plasma arc would be elliptical other than circular of the oridinary plasma arc. The torch design with two assistant orifices could be available to many fields such as plasma arc welding, especially to a welding torch with a large pressure chamber.

scholarly journals The Use of Chiro-Inositols in Asymmetric Synthesis

2021 ◽  
Author(s):  
◽  
Ghislaine Sarah Cousins
Keyword(s):  
Asymmetric Synthesis ◽  
Catalytic Effect ◽  
Michael Reaction ◽  
Aldol Reaction ◽  
Chiral Ligands ◽  
Chiral Auxiliaries ◽  
System A ◽  
Future Work ◽  
Amino Ether ◽  
The Michael Reaction

<p>D- and L- chiro-inositols are readily and inexpensively available as their O-methyl ethers pinitol and quebrachitol. To date the use of the choro-inositols in synthesis has not been exploited as fully as that of the more common isomer myo-inositol. The chiro-inositols were protected as either the di-isopropylidene or the di-cyclohexylidene systems to give them more steric bulk and were subsequently evaluated in the three areas of asymmetric synthesis: as chiral reagents, as chiral auxiliaries, as chiral ligands. Outside of these areas was the successful application of methodology for the mono esterification of C-2 symmetric diols to these inositol systems. This allowed a series of molecules to be generated that proved useful in the areas outlined above. For the use of chiro-inositols as chiral reagents, two reagents were investigated. The first was a hydroboration reagent similar to pinenyl borane. The second was the generation of a strained silacycle for use as a reagent in the enantioselective allylation of aldehydes. In the area of chiral auxiliaries, these inositols were successfully used to give selectivity in the Michael reaction. Unfortunately this success was not repeatable in the aldol reaction. Investigations into the development of chiral ligands were unsuccessful in that we were unable to synthesize either a diamine or an amino alcohol from this system. A diol and an amino ether were trialed in asymmetric reactions but failed to provide any catalytic effect. This section of the project did lead to some interesting chemistry and a better understanding of this system that can be applied to future work.</p>

scholarly journals Requirements engineering for User-Centered school food ordering system

2020 ◽  
Vol 17 (1) ◽  
pp. 357
Author(s):  
Diyana Binti Halim Khoo ◽  
Afdallyna Fathiyah Harun ◽  
Saiful Izwan Suliman
Keyword(s):  
System Design ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Perceived Ease Of Use ◽  
School Food ◽  
Technology Design ◽  
User Requirement ◽  
System A ◽  
Future Work ◽  
User Centered

<span>Understanding user requirement for a technology design is central to user experience. A user-centered technology design should consider user needs and constraints as well as abide to the principles of HCI design heuristics. This paper describes the requirements gathering for Kantin Online System, a school food ordering system where we considered the needs and constraints of different stakeholders involved and elicit a compromise where the needs of all parties can be met. We then applied usability heuristics into the system design to facilitate perceived ease of use and perceived usefulness. We conclude this paper with experts’ evaluations towards the heuristic elements of the system design concept and possible future work.</span>

scholarly journals MARSIPAN-based Early Warning Signs System: A full Audit cycle in the Inpatient Eating Disorders Ward

2019 ◽  
Author(s):  
Konstantinos Ioannidis ◽  
Gabriella Lewis ◽  
Jane Waterston ◽  
Carol Connolly ◽  
Felix Clay ◽  
...  
Keyword(s):  
Eating Disorders ◽  
Early Warning ◽  
Warning Signs ◽  
Warning Sign ◽  
Design Problems ◽  
System A ◽  
Early Warning Signs ◽  
Early Warning Sign ◽  
Audit Cycle ◽  
Future Work

Aims and method: We aimed to evaluate the MARSIPAN-guidance-adapted Early Warning Sign system (MARSI-MEWS) in respect to clinical governance standards for accuracy and completion. We performed a full audit cycle; between audit rounds, we addressed intrinsic information design problems related to the form in operation and provided guidance to staff on how to use this specialized tool. Result: Overall completeness of recording and scoring of MARSI-MEWS improved from 82.0% to 99.5% (χ2, p&lt;0.001). The accuracy of MARSI-MEWS scoring improved from 80% to 93% (χ2, p&lt;0.001). False recording of diastolic blood pressure dropped from 98% to 0% (χ2, p&lt;0.001). Clinical implication: This result suggests that the MARSI MEWS track-and-trigger system is suitable for use in inpatient eating disorders ward in regard to its completeness and accuracy standards. Specific training for staff might be essential in order to complete the tool effectively, and the validity of the tool should be tested in future work.

Development of an operational forecast verification system

2020 ◽  
Author(s):  
Georgios Boumis ◽  
Daniel Twigt ◽  
Jan Verkade
Keyword(s):  
Significant Contribution ◽  
Informed Decision Making ◽  
Global Flow ◽  
Forecast Verification ◽  
Operational Forecast ◽  
System A ◽  
Verification System ◽  
Forecasting System ◽  
Future Work

&lt;p&gt;Verification provides the answer to the question &quot;How good is my forecast?&quot;. Knowing the quality of a forecasting system provides a necessary baseline for improvement of that quality. It also contributes to forecast informed decision making, as verification provides a baseline estimate of residual uncertainties.&amp;#160;&lt;/p&gt;&lt;p&gt;To monitor the quality of the forecasts produced by Deltares Global Flow Forecasting system, a prototype of an operational forecast verification system was developed. The verification system comprises various components including the Ensemble Verification System (EVS), the Deltares OpenArchive and the Delft-FEWS forecast production system. Relevant verification metrics are computed by the EVS, which are subsequently stored and displayed in the forecasting system. This will allow for robust, automated forecast verification, and the usage of this information during the real-time forecasting process. &amp;#160;&lt;/p&gt;&lt;p&gt;Future work on the system will include a post-processing routine which will cast the verification information in a format suitable for publication to both existing and prospective GLOFFIS clients. Over the years, the system's outcomes are expected to provide a significant contribution to the quality of the GLOFFIS forecasts.&amp;#160;&lt;/p&gt;&lt;p&gt;In parallel, the system is being applied to various other operational hydrological forecasting systems around the globe.&lt;/p&gt;

Purely Analog Fractional Order PI Control Using Discrete Fractional Capacitors (Fractors): Synthesis and Experiments

2009 ◽  
Author(s):  
Shayok Mukhopadhyay ◽  
Calvin Coopmans ◽  
YangQuan Chen
Keyword(s):  
Fractional Order ◽  
Digital Control ◽  
Circuit Board ◽  
Pi Control ◽  
Control Techniques ◽  
System A ◽  
Analog Control ◽  
Tank System ◽  
Digital Methods ◽  
Future Work

This paper presents the results of experiments related to analog fractional order PI control of a coupled tank system. A custom circuit board has been built to perform analog PID/FOPID control. Specialized circuit elements called ‘Fractors’ [1] are used to perform fractional order integration/differentiation of the error signals. The design of the board, subsequent experimentation and its comparison to similar digital control techniques have been presented. The benefits of purely analog control when dealing with non-linearities are also discussed. Further, methods of approximating a particular fractional order α* with any number of practically available orders α1, α2, ....αn has also been presented. The conclusion of this work examines the need for purely analog control as opposed to widespread digital methods and also lays down definite directions for future work.

scholarly journals Agent-based Market Research Learning Environment for New Entrepreneurs

Respuestas ◽  
2012 ◽  
Vol 17 (1) ◽  
pp. 11-19
Author(s):  
Alejandro Valencia ◽  
Oscar Salazar ◽  
Demetrio Ovalle ◽  
Gabriel Awad
Keyword(s):  
Learning Environment ◽  
Market Research ◽  
Research Strategies ◽  
Agent Based ◽  
Prototype Development ◽  
System A ◽  
Systems Learning ◽  
Market Niche ◽  
Development And Validation ◽  
Future Work

Due to the importance of creating alternative mechanisms to generate know-how on potential markets for new entrepreneurs this paper proposes an agent-based learning environment to help them learning market research strategies within new businesses. An instructor agent, serving as a learning assistant within the MAS environment guides new entrepreneurs to identify their most adequate market niche. The integration of MAS-CommonKADS and GAIA methodologies is used along with AUML diagrams in order to design and develop this agentbased learning environment, called MaREMAS. The paper thus describes all the stages concerning MaREMAS construction focusing on the conceptualization, analysis, design, prototype development, and validation. The tests developed in the MaREMAS learning environment were satisfactory, however, it is proposed as future work to provide the system a more robust statistical module that allows a better analysis of the research variables and hence be able to generate more useful suggestions to the entrepreneur.Keywords: Agent-based learning environments, market research strategies, entrepreneurship, intelligent learning systems, learning helpers modeling

scholarly journals SOME SAND TRANSPORT PHENOMENA OH COASTS WITH BARS

1970 ◽  
Vol 1 (12) ◽  
pp. 54 ◽  
Author(s):  
M. Dyhr-Nielson ◽  
Torben Sorensen
Keyword(s):  
Fluid Dynamics ◽  
Transport Phenomena ◽  
Present Knowledge ◽  
Quantitative Approach ◽  
Sand Transport ◽  
Shore Zone ◽  
Secondary Currents ◽  
Sediment Movement ◽  
System A ◽  
Complex Phenomena

Longshore wave currents and their influence on the sand transport phenomena m the shore zone have attracted the attention of numerous researchers. Also the existence of transverse, secondary currents, superposing the longshore component, has been known for years, but less attention has been given to analysis of their effect on the sediment movement. This paper presents some examples of the influence, these relatively weak transverse currents may have on the processes in the shore zone. They have a parallel in the effect of secondary currents in alluvial streams, which, although weak, give use to such an impressive phenomenon as meandering. All conclusions below are based on simple, qualitative considerations of the physics of the system. A strict mathematical, quantitative approach to the problem does not seem possible with the present knowledge of the fluid dynamics in the shore zone, and much further research into these complex phenomena remains, of course, necessary.

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