Numerical Investigation of New Design of the Etoile Flow Straightener

2011 ◽  
Author(s):  
Boualem Laribi ◽  
Abdelkader Youcefi ◽  
Djelloul Belkacemi
Keyword(s):  
Velocity Profile ◽  
Numerical Investigation ◽  
Flow Behavior ◽  
Flow Parameters ◽  
Flow Metering ◽  
High Fluid ◽  
High Turbulence ◽  
High Level ◽  
High Degree ◽  
Very High

Flow metering of industrial fluids remains the concern of several researchers and exporting countries of gas and oil in the world. It is in this context that a vast numerical investigation is done in our laboratory of Industrial Fluids Measurements and Applications (FIMA). This article examines numerically a new design of the Etoile flow straightener which is described by the standard ISO 5167. This new design consists in removing the central part of the Etoile which, according to researchers, leads to a very high level of turbulence. Our intervention relates to the development and the establishment of the flow parameters downstream the Etoile with and without central part. The flow is produced by air in a 100mm pipe diameter and 40D of length with a Reynolds number of 2.5×105. The disturbance is a valve maintained 100%, 50% and 30% open. The flow parameters examined are velocity profile, turbulence intensity profile, and the fluid gyration angle. The code CFD Fluent is used for this simulation. The results obtained are compared according to directives of the standard ISO 5167. The results obtained show that for the valve settings 30% and 50% open, upstream the Etoile, we have a high turbulence level and a velocity profile with recirculation zones more significant for the valve 30% open than for the valve 50% open. It is also noted that the valve develop very high fluid gyration angle apart from the standard values. The flow behavior downstream the central part of Etoile described by the ISO 5167 is well simulated with the valve open at 100%, with a deficit of flow and a very high degree of turbulence. At this stage for the two designs, the noticed results seem so identical beyond a certain stations downstream the Etoile.

Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta
Keyword(s):  
Removal Rate ◽  
Removal Rates ◽  
Carbon Removal ◽  
Biofilm Growth ◽  
Loading Rates ◽  
Biomass Activity ◽  
High Turbulence ◽  
The One ◽  
High Level ◽  
Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

scholarly journals Intensificación de la ganadería porcina y problemas medioambientales en la Conca de Tremp (Pirineo Catalán)

1997 ◽  
Author(s):  
José Borrás Ferrán ◽  
José Sánchez Sánchez
Keyword(s):  
Sustainable Development ◽  
Human Health ◽  
Environmental Impacts ◽  
Production System ◽  
Mountainous Regions ◽  
High Level ◽  
High Degree ◽  
Very High

La Conca de Tremp, situada en la comarca montañosa catalana del Pallars Jussá, es una de las áreas donde más se ha incrementado la ganadería porcina en régimen estabulado en las últimas tres décadas. Los impactos medioambientales negativos derivados de este sistema de producción ganadera son muy considerables, especialmente los relacionados con el vertido de puriñes que ha provocado un alto grado de nitrificación de las aguas. Análisis pormenorizados demuestran que el nivel de nitrificación de las aguas en la Conca de Tremp ha alcanzado un nivel muy alto, con las consecuencias que ello tiene en la salud de las personas. Atendiendo a las exigencias del desarrollo sostenible, única forma de garantizar el futuro de las comarcas de montaña, se apuntan soluciones para paliar los graves problemas generados por la intensificación de la ganadería porcina.The Tremp Basin, placed in the mountainous Catalonian region of the Pallars Jussá, is one of the areas where stabled pig cattle raising has been more increased in the last three decades. Negative environmental impacts, derived from this cattle raising production system are greatly substantial, specially the ones related to purine wastes which have caused a high degree of nitrification of the waters. Detailed analyses show that the degree of nitrification of the waters in the Tremp Basin has reached a very high level, with all that this implies for human health. Attending to the requirements of a sustainable development, which is the only way of granting a future for the mountainous regions, this paper hints at some solutions to lessen the serious problems generated by the intensification ofpig cattle raising.

Mutual trust and mutual gains: A recent Crown land use planning exercise in Ontario

2000 ◽  
Vol 76 (3) ◽  
pp. 425-427
Author(s):  
E. Craig McManus
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Mutual Trust ◽  
Vested Interests ◽  
Degree Of Confidence ◽  
High Level ◽  
High Degree ◽  
Very High

Negotiations between industry, environmental partnership and government were intense, demanding, and created a high degree of confidence, candour and openness among participants. Over a three-week period, a very high level of trust was developed as vested interests were left at the door. All parties were expected to, and did, operate in an honest and forthright fashion. At the end of the process, participants were able to deliver a document built on mutual gains. Each party could honestly say they had gained from the process and not merely acquiesced to a form of consensus. The "Ontario Forest Accord" is, by any measure, a tremendous step forward for industry, government and the environmental community.

Ring complexes of the Peruvian Coastal Batholith: a long-standing subvolcanic regime

1976 ◽  
Vol 13 (8) ◽  
pp. 1020-1030 ◽  
Author(s):  
M. A. Bussell ◽  
W. S. Pitcher ◽  
P. A. Wilson
Keyword(s):  
Structural Control ◽  
Direct Connection ◽  
History Of ◽  
Ring Complexes ◽  
High Level ◽  
High Degree ◽  
Very High

A special feature of the composite Coastal Batholith of Peru is the presence of ring complexes, which suggests a very high-level crustal environment and a direct connection between the magmas of the constituent plutons and caldera-centred volcanicity. The nature of four such complexes is commented on in detail, especially the high degree of structural control of emplacement, the association of mylonites and tuffisites with ring-fractures, the roles of stoping, fluidization and entrainment during the intrusion of ring-dykes, the co-existence of highly mobile magmas, their pulsatory injection, and the connection between these and volcanics of the same general age. Such mechanisms of cauldron subsidence located at the plutonic–volcanic interface operated throughout much of the 70 m.y. history of the batholith.

scholarly journals The reality of management by roaming practice of principles of Tatweer schools in Riyadh

2019 ◽  
Vol 3 (12) ◽  
Author(s):  
Nof Ahmed Al-Hawishl
Keyword(s):  
Response Category ◽  
High Response ◽  
Survey Method ◽  
Main Question ◽  
Arithmetic Average ◽  
General Average ◽  
Level Of Significance ◽  
High Level ◽  
High Degree ◽  
Very High

The aim of this research is to recognize the reality of management by roaming practice of principles of Tatweer schools in Riyadh, through answering the main question of the research: What is the reality of management by roaming practice of principles of Tatweer schools in Riyadh? And for achieving that the researcher used the descriptive approach and the survey method, the questionnaire was used as a tool of the research consisting of (47) clauses and distributed over three axes. The sincerity and stability of the tool was confirmed by appropriate statistical and educational methods. The research has found out many results the most notably is that management by roaming practice of principles of Tatweer schools in Riyadh in all its fields was in a very high degree with a general average reached (4.46) of the very high response category, where the guidance field ranked first with an arithmetic average of (4.67) of the very high response category, followed by organization field with an arithmetic average of (4.49) in the very high response category, then the field of ​​planning with an arithmetic average of (4.39) in the very high response category, while the supervision field was in the last order with an arithmetic average of (4.26) in the very high response category. And the center of the obstacles of management by roaming practice of principles of Tatweer schools in Riyadh was in a high level with an arithmetic average of (3.81) in the high response category. The study also mentioned that there were no statistically significant differences at the level of significance of (0.05) in the view of the sample attributable to variable years of experience, variable qualification and variable size of the building, while the focus of the proposals that contribute to management by roaming of the directors of the Tatweer schools in Riyadh, has a high degree of approval with an arithmetic average of (4.01) in the high response category.

Numerical Investigation of the Transient Flow in a Centrifugal Pump Stage

2005 ◽  
Author(s):  
F.-K. Benra ◽  
H. J. Dohmen
Keyword(s):  
Numerical Investigation ◽  
Centrifugal Pump ◽  
Transient Flow ◽  
Flow Behavior ◽  
Centrifugal Pumps ◽  
Flow Parameters ◽  
Pump Stage ◽  
Dependent Flow ◽  
Return Channel ◽  
Grid Nodes

The knowledge of the flow behavior in pump stages which consist of an impeller, a bladed diffuser and a bladed return channel is of great importance for the design of multistage centrifugal pumps. Especially the Interaction of the impeller flow with the stationary diffuser blades and the behavior of the return channel blades affect the efficiency of a pump stage in a considerable way. In this contribution the transient flow in an industrial centrifugal pump stage, which has an impeller with seven blades, a radial diffuser with ten blades and a return channel with also ten separate blades, has been simulated numerical by using the commercial software code CFX-5.7. Because of the unfavorable ratio of blade numbers a complete meshing of all flow channels was necessary. In consequence the cumulative amount of grid nodes reached a number of nearly 6 million nodes. As a result of the numerical investigation of the time dependent flow accomplished for this contribution, the influence of the rotating impeller on the flow in the stationary parts of the pump is presented in detail. All flow parameters are shown as a function of time and are discussed with respect to the position of the impeller relative to the stator blades.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

A Low-Noise, High-Gain Quasi-Millimeter-Wave Receiver MMIC with a Very High Degree of Integration Using 3D-MMIC Technology

2011 ◽  
Vol E94-C (10) ◽  
pp. 1548-1556 ◽  
Author(s):  
Takana KAHO ◽  
Yo YAMAGUCHI ◽  
Kazuhiro UEHARA ◽  
Kiyomichi ARAKI
Keyword(s):  
Millimeter Wave ◽  
High Gain ◽  
Low Noise ◽  
High Degree ◽  
Very High ◽  
Millimeter Wave Receiver

ANTICYTOKINE ACTIVITY OF THE PROTOZOA BLASTOCYSTIS SPP

2020 ◽  
pp. 44-48
Author(s):  
Bugero N.V. ◽  
Ilyina N.A. ◽  
Aleksandrova S.M.
Keyword(s):  
Gastrointestinal Tract ◽  
Gastrointestinal Diseases ◽  
Control Group ◽  
Ulcer Disease ◽  
Cytokine Balance ◽  
High Prevalence ◽  
Blastocystis Spp ◽  
High Level ◽  
Eukaryotic Organisms ◽  
High Degree

In addition to the classical pathogens, which are well understood and well identified, new pathogens with the potential to spread epidemiologically are being identified. Some of these little-known organisms are the simplest Blastocystis spp. blastocystostosis. The clinical significance of Blastocystis spp. and its pathogenicity are still under discussion. This parasite belongs to a group of single-celled eukaryotic organisms living in the colon of the human intestine. Blastocystis spp. is known to be found both in people with reduced immune status and in individuals without any clinical manifestation. It has been established that a sufficiently high degree of invasiveness is observed in persons with gastrointestinal tract diseases, dermatosis, allergic reactions, in patients with carriers of the human immunodeficiency virus, etc. Possessing persistence factors, protozoa blastocysts contribute to the inactivation of host defensive mechanisms, providing a stable anthogonistic effect. In recent years, many works have been devoted to the characteristics of the persistent properties of Blastocystis spr., however, individual properties of blastocysts, in particular, anticytokine activity (ACA), have not yet been studied. In this regard, the work studied the anticytokine activity of microorganisms isolated from healthy subjects and patients with gastrointestinal tract diseases. A high prevalence of the studied characteristic in the subjects was shown. The expression of anticytokine activity in the obtained isolates of blastocysts was the highest in the group of persons with gastric ulcer disease, which decreased in the order of duodenal ulcer, chronic cholecystitis, chronic gastritis, etc. The data obtained in this work on the high level of ACA expression in blastocyst isolates obtained from individuals with gastrointestinal diseases as compared with the control group enables to conclude that their exometabolites may influence the local cytokine balance [1], which supports the inflammatory process.

التغير المناخي واثره في المقنن المائي لمحصول العنب في محافظة ديالى

2019 ◽  
Vol 1 (34) ◽  
pp. 391-422
Author(s):  
اشواق حسن حميد صالح
Keyword(s):  
Climate Change ◽  
Statistical Analysis ◽  
Wind Speed ◽  
Extreme Temperature ◽  
Solar Brightness ◽  
The Subject ◽  
Climate Station ◽  
The Times ◽  
High Level ◽  
Very High

Climate change and its impact on water resources is the problem of the times. Therefore, this study is concerned with the subject of climate change and its impact on the water ration of the grape harvest in Diyala Governorate. The study was based on the data of the Khanaqin climate station for the period 1973-2017, (1986-2017) due to lack of data at governorate level. The general trend of the elements of the climate and its effect on the water formula was extracted. The equation of change was extracted for the duration of the study. The statistical analysis was also used between the elements of the climate (actual brightness, normal temperature, micro and maximum degrees Celsius, wind speed m / s, relative humidity% The results of the statistical analysis confirm that the water ration for the study area is based mainly on the X7 evaporation / netting variable, which is affected by a set of independent variables X1 Solar Brightness X4 X5 Extreme Temperature Wind Speed ​​3X Minimal Temperature and Very High Level .

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