Design and Analysis of Volute Casing: A Review

2012 ◽  
Author(s):  
Beena D. Baloni ◽  
S. A. Channiwala
Keyword(s):  
Flow Structure ◽  
Future Development ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Advantages And Disadvantages ◽  
Flow Domain ◽  
The Impact ◽  
Insight Into

Future development of more efficient volute casing depends on improving understanding of the design and flow analysis of the volute casing. This paper reviews different aspects of design and flow behavior inside the volute casing. It describes advantages and disadvantages of the different designs, the relation between flow and geometry, the impact on the impeller and the flow behavior inside the volute. The main purpose is to provide an insight into the flow structure that can be used later to improve the performance or remediate some problems. The use of CFD is also discussed for the flow domain.

ANALYSIS OF BLOOD FLOW PASSING THROUGH AORTIC AND MITRAL VALVES USING A COMPUTATIONAL MODEL OF CONCENTRATED PARAMETERS

2014 ◽  
Vol 26 (06) ◽  
pp. 1450068
Author(s):  
J. Del Río Palma ◽  
E. Romero V. ◽  
M. Cerrolaza
Keyword(s):  
Blood Flow ◽  
Heart Valves ◽  
Computational Models ◽  
Flow Behavior ◽  
Flow Analysis ◽  
High Mobility ◽  
Abnormal Behavior ◽  
Factors Affecting ◽  
Main Factors ◽  
The Impact

Blood flow has been extensively studied because of its close relationship with cardiovascular disease. Heart valves blood flow analysis is particularly complex due to the high mobility of its leaflets, a fact that has stimulated the development of computational models aimed to its better understanding. For studying heart valves blood flow, we developed a mathematical model derived from clinical observations based on echocardiographic images, which describe valve leaflets motion and its influence on blood flow. This work presents a concentrated-parameters-based model of heart valves blood flow that takes into consideration five main factors affecting such a flow in the mitral and aortic valves. This model considers factors that are related to blood fluid and valve leaflets characteristics. Considering the main factors involved, it was found that blood flow exhibit an abnormal behavior in response to small variations (less than 10%) in blood pressure gradient or in leaflets stiffness. Likewise, after changing the roughness of the leaflets, the impact is smaller, only slightly affecting blood flow behavior with changes beyond 30%. Moreover, it was observed that the influence of fluid vortices originated behind the valves can be disregarded and the kinetic energy induced by them is almost negligible.

Extended Fractional-Flow Model of Low-Salinity Waterflooding Accounting for Dispersion and Effective Salinity Range

SPE Journal ◽  
2019 ◽  
Vol 24 (06) ◽  
pp. 2874-2888 ◽  
Author(s):  
Hasan Al–Ibadi ◽  
Karl D. Stephen ◽  
Eric J. Mackay
Keyword(s):  
Relative Permeability ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Salinity Range ◽  
Fractional Flow ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Low Salinity Waterflooding ◽  
Salinity Water ◽  
The Impact

Summary Low–salinity waterflooding (LSWF) is an emergent technology developed to increase oil recovery. Laboratory–scale testing of this process is common, but modeling at the production scale is less well–reported. Various descriptions of the functional relationship between salinity and relative permeability have been presented in the literature, with respect to the differences in the effective salinity range over which the mechanisms occur. In this paper, we focus on these properties and their impact on fractional flow of LSWF at the reservoir scale. We present numerical observations that characterize flow behavior accounting for dispersion. We analyzed linear and nonlinear functions relating salinity to relative permeability and various effective salinity ranges using a numerical simulator. We analyzed the effect of numerical and physical dispersion of salinity on the velocity of the waterflood fronts as an expansion of fractional–flow theory, which normally assumes shock–like behavior of water and concentration fronts. We observed that dispersion of the salinity profile affects the fractional–flow behavior depending on the effective salinity range. The simulator solution is equal to analytical predictions from fractional–flow analysis when the midpoint of the effective salinity range lies between the formation and injected salinities. However, retardation behavior similar to the effect of adsorption occurs when these midpoint concentrations are not coincidental. This alters the velocities of high– and low–salinity water fronts. We derived an extended form of the fractional–flow analysis to include the impact of salinity dispersion. A new factor quantifies a physical or numerical retardation that occurs. We can now modify the effects that dispersion has on the breakthrough times of high– and low–salinity water fronts during LSWF. This improves predictive ability and also reduces the requirement for full simulation.

scholarly journals The future of the EU in the context of scenarios for its development by 2025

2018 ◽  
Vol 5 (11) ◽  
pp. 60-70
Author(s):  
O. М. Rudik
Keyword(s):  
European Commission ◽  
Future Development ◽  
New Technologies ◽  
White Paper ◽  
Single Market ◽  
The European Union ◽  
Advantages And Disadvantages ◽  
The Future ◽  
The Impact ◽  
The Eu

The article researches the scenarios for the future development of the EU by 2025 proposed by the European Commission. The white paper on the future of EU looks at how Europe will change in the next decade, from the impact of new technologies on society and jobs, to doubts about globalization, security concerns and the rise of populism. The European Commission emphasizes that the Europe’s role as a positive global force is more important today than ever. However, under the pressure of global competition the United Europe’s place in the world and its economic weight are shrinking, which is a solid foundation for preserving the unity of the Union for the sake of achieving greater. On the contrary, the most desirable scenario, as can be seen from the speech by the President of the European Commission, is to give the European Union a greater amount of power, resources and decision-making powers. As a result, cooperation between the EU-27 Member States will deepen in all areas than ever before. The White Paper outlines ve main scenarios («Carrying on», «Nothing but the single market», «Those who want more do more», «Doing less more e ciently», «Doing much more together»), each of them provides an opportunity to look at the possible state of a airs in the Union by 2025, depending on the choice that the EU will make by 2019. In the opinion of Jean-Claude Juncker, the most negative scenario of the EU development, and therefore extremely undesirable, is to bring its goals to purely economic, focusing the Union’s activities on the development of a single internal market and ensuring its uninterrupted functioning («Nothing but the single market» scenario). Based on data from the European Commission the author shows and brie y describes the key advantages and disadvantages of each of the scenarios. The common features of these scenarios are outlined: rst, they all come from the fact that the United Kingdom withdraws from the EU; secondly, none of them doubts the need to preserve the euro as common currency and the Schengen zone, thirdly, neither the scenarios refers to further EU enlargement. Since none of the proposed scenarios provides for the complete disintegration of the EU, that is, the disappearance of it as a geopolitical actor, it is concluded that in the strategic perspective all the outlined models of the EU’s future development suit Ukraine. Moreover, the steps recently proposed by the President of Ukraine and the European Parliament for deepening the economic integration of Ukraine with the EU and its association with the Schengen area also does not contradict any of the scenarios.

Simulating Knowledge Sharing in Spatial Planning: An Agent-Based Approach

2009 ◽  
Vol 36 (4) ◽  
pp. 644-663 ◽  
Author(s):  
Arend Ligtenberg ◽  
Adrie Beulens ◽  
Dik Kettenis ◽  
Arnold K Bregt ◽  
Monica Wachowicz
Keyword(s):  
Knowledge Sharing ◽  
Future Development ◽  
Spatial Planning ◽  
Input Data ◽  
Multiagent System ◽  
Planning Process ◽  
Shared Vision ◽  
Agent Based ◽  
The Impact ◽  
Insight Into

This paper presents a multiagent system (MAS) that simulates a multiactor interactive spatial-planning process. The MAS extends an existing approach with the principle of sharing knowledge between participating actors while trying to create a shared vision. In the simulation, actors are modelled as agents. They have desires and preferences regarding the future development of their environment. These are used to develop their individual views on what areas are eligible for change. A facilitator agent coordinates the exchange of information by indicating possible solutions and conflicts to the actor agents. The simulation is demonstrated for an allocation problem in a pilot area in the southeast of the Netherlands. Four different scenarios are implemented, which demonstrate the impact of cooperation and hierarchy during an interactive spatial-planning process. Although the model is kept limited in terms of input data, the results show its potential for providing insight into the relations and interaction between actors, rather than predicting the results of an interactive spatial-planning process.

scholarly journals Schlieren Visualization of Shaping Air during Operation of an Electrostatic Rotary Bell Sprayer: Impact of Shaping Air on Droplet Atomization and Transport

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 279 ◽  
Author(s):  
Adnan Darwish Ahmad ◽  
Ahmad Abubaker ◽  
Ahmad Salaimeh ◽  
Nelson Akafuah
Keyword(s):  
Automotive Industry ◽  
Flow Behavior ◽  
Paint Film ◽  
Target Surface ◽  
Operating Conditions ◽  
Centrifugal Forces ◽  
Droplet Transport ◽  
The Impact ◽  
Insight Into

Electrostatic rotary bell sprayers (ERBSs) are widely used in the automotive industry. In ERBS, atomization is facilitated using centrifugal forces which disintegrate the paint film inside the cup into droplets at the cup edge. The droplets are then transported by the flow of a shaping air (SA) and electrostatic forces to a target surface; the characteristics of these droplets dramatically influence the quality of a painted surface and the painting transfer efficiency. In the current paper, a novel Schlieren-based visualization of the shaping air in the absence of paint droplets was performed during a qualitative investigation to delineate shaping air flow behavior and its interaction with droplets and droplet transport. An infrared thermographic flow visualization (IRFV) method and droplet size measurement were used to complement the Schlieren data for providing insight into shaping air-droplet interactions. The results demonstrated the impact of different operating conditions on the SA flow pattern, and the influence SA has on the secondary atomization and transport of droplets. Hence, these experimental methods combine with a useful tool for optimizing SA configurations that improve spray quality, droplet transport, and the efficiency of ERBS operations.

Investigation on the control of multiphase flow behavior in a continuous casting tundish during ladle change

2020 ◽  
Vol 117 (6) ◽  
pp. 619
Author(s):  
Rui Xu ◽  
Haitao Ling ◽  
Haijun Wang ◽  
Lizhong Chang ◽  
Shengtao Qiu
Keyword(s):  
Multiphase Flow ◽  
Flow Behavior ◽  
Rolled Strip ◽  
Impact Zone ◽  
Steel Cleanliness ◽  
Carry Over ◽  
Slag Carry Over ◽  
Hot Rolled ◽  
Turbulence Inhibitor ◽  
The Impact

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.

The Management of Post-Tonsillectomy Morbidity in Patients With Sleep Apnoea

2019 ◽  
Vol 70 (10) ◽  
pp. 3738-3740
Keyword(s):  
Day Surgery ◽  
Sleep Apnoea ◽  
Integrative Approach ◽  
Multicenter Studies ◽  
Therapeutic Modalities ◽  
Advantages And Disadvantages ◽  
Obstructive Sleep ◽  
Wide Range ◽  
The Impact ◽  
Surgery Center

The Tonsillectomy in children or adults is an intervention commonly encountered in the ENT (Ear Nose and Throat) and Head and Neck surgeon practice. The current tendency is to perform this type of surgery in major ambulatory surgery centers. Two objectives are thus pursued: first of all, the increase of the patient quality of life through the reintegration into the family as quickly as possible and secondly, the expenses associated with continuous hospitalization are reduced. Any tertiary (multidisciplinary) sleep center must ensure the complete diagnosis and treatment (including surgery) of sleep respiratory disorders. Under these conditions the selection of patients and especially the implementation of the specific protocols in order to control the postoperative complications it becomes essential. The present paper describes our experience of tonsillectomy as treatment for selected patients with chronic rhonchopathy (snoring) and mild to moderate obstructive sleep apnoea. It was presented the impact of antibiotics protocols in reducing the main morbid outcomes following tonsillectomy, in our day surgery center. The obtained results can also be a prerequisite for the integrative approach of the patients with sleep apnoea who were recommended surgical treatment. Considering the wide range of therapeutic modalities used in sleep apnoea, each with its specific advantages and disadvantages, more extensive and multicenter studies are needed. Keywords: post-tonsillectomy morbidity, day surgery center, sleep disorders

The Good, the Bad and the Ugly
. A Broad look at the Adaptation of Technology in Education

2020 ◽  
Vol 2 (1) ◽  
pp. 31-44
Author(s):  
Vladislav Ilin
Keyword(s):  
Technology In Education ◽  
Advantages And Disadvantages ◽  
Standardized Method ◽  
Impact Of Technology ◽  
The Impact ◽  
The Way

Technology in education is a global phenomenon affecting learners of all ages. The breadth and variety of available tools make it difficult to implement a standardized method for assessing the impact of technology on learning. The lack of a consensus on good and bad practices results in inconsistent application and mixed learning results.   This article takes a look at the adaptation of technology to education and examines the various tools used to enhance learning. We discuss the advantages and disadvantages of using technology, as well as review methodologies for evaluating the impact.   The essay concludes by identifying several problems with the way technology is evaluated and offers suggestions for further research to address those problems.

Unfunded Public Employee Health Care Benefits and GASB No. 45

2007 ◽  
Vol 21 (3) ◽  
pp. 245-263 ◽  
Author(s):  
Elizabeth K. Keating ◽  
Eric S. Berman
Keyword(s):  
Health Care ◽  
Financial Reporting ◽  
Full Range ◽  
Financial Reports ◽  
Employment Benefits ◽  
Care Plans ◽  
Advantages And Disadvantages ◽  
Government Accounting ◽  
The Government ◽  
The Impact

The Government Accounting Standards Board (GASB) recently released Statement No. 45, Accounting and Financial Reporting by Employers for Post-Employment Benefits Other Than Pensions and its companion Statement No. 43 for pooled stand-alone health care plans, which will profoundly affect American governmental finance. The goal of this article is to encourage governments to consider carefully a full range of options in funding and restructuring other post-employment benefits (OPEB). This article will review Statement No. 45's potential impact on governments and review existing disclosures in financial reports as well as bond offering statements. The article will discuss the statement's impact on budgets and governmental operations, including collective bargaining. Funding options under Statement No. 45 will be detailed, including the advantages and disadvantages of irrevocable trusts and OPEB bonds. The article will also discuss the impact of Medicare Part D subsidies received by governments, as well as the bond rating implications of policy decisions surrounding OPEB. As the largest government entities are just now implementing GASB Statement No. 45, estimates of the magnitude of unfunded OPEB liabilities are limited as are the strategies likely to be adopted to cover these obligations. This article offers a summary of the unfunded OPEB liabilities reported by states and major cities and suggests some measures for assessing the ability of these entities to address these costs.

scholarly journals Moving online: young people and parents’ experiences of adolescent eating disorder day programme treatment during the COVID-19 pandemic

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Phillipa Louise Brothwood ◽  
Julian Baudinet ◽  
Catherine S. Stewart ◽  
Mima Simic
Keyword(s):  
Young People ◽  
Day Treatment ◽  
Free Text ◽  
Treatment Delivery ◽  
Therapeutic Practice ◽  
Advantages And Disadvantages ◽  
Online Treatment ◽  
The Everyday ◽  
Lost In Translation ◽  
Insight Into

Abstract Background This study examined the experiences of young people and their parents who attended an intensive day treatment programme for eating disorders online during the global COVID-19 pandemic. Methods Online questionnaires were completed by 14 adolescents (12–18 years) and their parents (n = 19). The questionnaires included a mixture of rating questions (Likert scale) and free text responses. Free text responses were analysed using reflexive thematic analysis. Results Three main themes were identified: 1) New discoveries, 2) Lost in translation and 3) The best of a bad situation. This study provides insight into the benefits and pitfalls of online treatment delivery in the adolescent day programme context, which has rapidly had to become part of the everyday therapeutic practice. Results indicate that there are advantages and disadvantages to this, and that parents and young people’s views differed. Conclusions This study suggests that the increased accessibility provided by online working does not necessarily translate to increased connection. Given the importance of therapeutic alliance in treatment outcomes, this will be an important consideration for future developments of online intensive treatments.

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