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Author(s): 

AUTY R.

Journal: 

RESOURCES POLICY

Issue Info: 
  • Year: 

    2001
  • Volume: 

    27
  • Issue: 

    1
  • Pages: 

    25-32
Measures: 
  • Citations: 

    1
  • Views: 

    136
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2024
  • Volume: 

    50
  • Issue: 

    3
  • Pages: 

    731-741
Measures: 
  • Citations: 

    0
  • Views: 

    12
  • Downloads: 

    0
Abstract: 

The temperature of the solar atmosphere steeply increases in the Transition Region from the chromosphere to the corona. In the coronal temperatures, the coronal hole, quiet sun, and active Regions are visible in the solar corona. The magnetic field controls the solar corona. Different physical processes (e.g. magnetic reconnection, waves) play a role in the coronal dynamics, which cause plasma heating to millions of degrees. Then, it is essential to understand the role of these processes. A more exact analysis of the emission line profiles to investigate the dynamics and thermal behavior of the coronal and Transition Region plasma is spectroscopy. The spectral line profiles are proof of the structural evolution of the magnetic field and plasma temperature in the coronal holes and quiet sun. So far, the study of coronal spectral lines indicates that most line profiles are well-fitted based on a single Gaussian profile. However, some spectral lines avoid from a single Gaussian model because they have least one excess component. Observations display that 5 % to 10 % of line profiles have the blueward asymmetry in the quiet sun and coronal holes. Considering the mentioned advantages of spectroscopy, we use the formed Si IV 1394 Å spectral line in the Transition Region from the Interface Region Imaging Spectrograph (IRIS) raster in a central-equatorial Region of Sun on 14 October 2015. Also, we make co-spatiotemporal raster images from Atmospheric Imaging Assembly (AIA) 193 Å, IRIS/SJI 1330 Å and Helioseismic and Magnetic Imager (HMI) magnetograms. Our data includes quiet sun, coronal hole and bright points features. The Si IV 1394 Å spectral line profiles are fitted with the single and then with double Gaussian function. We apply three essential conditions to certify any spectral profiles as asymmetric profile by double Gaussian model, that is, (1) the asymmetric profile must have a goodness-of-fit greater ( ) than one for the single Gaussian fits, (2) the minimum intensity of the first and second component to be 20 DN and (3) the distance between the centers of the two components to be more significant than 20 km/s. 1598 asymmetric profiles that are found out of a total of 103,000 profiles. The four types of profiles are dominated as only blue wing, only red wing, two clear peaks and none of the three types (it has two wings). The most significant number of asymmetric profiles corresponds to a profile with a component on its blue side. The lowest number is possessed by profiles inconsistent with single and double Gaussian fitting models (two wings). The asymmetries are concentrated on positions with high magnetic flux density. Also, asymmetric profiles arise in the large-scale bright lane-like areas in the SJI 1330 Å raster map. Corresponding to these areas, the magnetic flux concentration in the HMI raster map shows most probably, the network lanes. This correspondence can indicate the magnetic source. The asymmetric profiles may be owing to the reconnection of the open magnetic field of coronal hole with the bright points’ loops for bright points inside and the boundary of coronal hole. Also, we may contemplate a similar plan for asymmetric profiles at the coronal hole boundary, where the open magnetic fields of coronal hole may be reconnected with the quiet sun's close loops. However, the asymmetry of profiles at quiet sun may be owing to the reconnection of closed loops at this Region. It is clear that the blueward and redward asymmetry are signatures of downflow, and upflow that may be caused by magnetic reconnection. However, the bidirectional jets derived from magnetic reconnection at the forming height of Si IV 1394 Å may be a reason for the asymmetric profiles with two clear peaks and two wings. Magnetic reconnections below the formation height of Si IV 1394 Å in the Transition Region may be a reason for upflows. Also, the profiles with blue wing may be relevant to the upflow spread of jets. These profiles are mainly sited away from the jet footpoints and on the network jets. The reconnection events above the formation height of Si IV 1394 Å or coronal return flows may be a reason for downflows. The red wing of the spectral line profiles is probably relevant to the downflow arising from reconnections that mainly placed around the footpoints of grid jets.

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Issue Info: 
  • Year: 

    2023
  • Volume: 

    11
  • Issue: 

    2
  • Pages: 

    133-152
Measures: 
  • Citations: 

    0
  • Views: 

    214
  • Downloads: 

    30
Abstract: 

ABSTRACT The attention of contemporary planners to environmental factors and increasing awareness and communication of man with his surrounding environment has increased the layers and defining factors of design and planning concepts. In such a way, a common problem with the issue of environmental capabilities to respond was put in front of the planners. The collection of ideas presented in this era was in the form of responsive planning, focusing on the maximum use of environmental capabilities. The necessity of the emergence of a comprehensive discourse to overcome the plurality of factors, definitions and design methods in the environmental fields has been given less attention. Based on this, the current research aims to organize the leading theories in this field in a targeted manner and seeks to improve them based on their synergy. The structural question of this research is the meanings, examples and meaningful contexts of flexibility in various aspects and scales of urban planning. The research method used is qualitative thematic analysis with the help of artificial intelligence in MAXQDA software in a 6-step processing process. The important application of this research is to structure the minds of the planners of this field to reduce the scattered and interdisciplinary problems of the resources. The results of this research revealed dimensions such as identification and recognizability, diversity and changeability, adaptability and expandability, distribution, separation and continuity, organization and compatibility in the field of flexibility and related to the corresponding parts in urban planning   Extended Abstract Introduction Responsiveness-based design and planning emphasizing the maximum use of environmental capacities to meet users' needs implicitly cause a targeted improvement of environmental quality. As the environmental awareness of contemporary man has expanded and the platforms have become more diverse, many challenges are raised in the field of environment-oriented in the field of infrastructure quality and service provision. Urban developments and new developments in cities should be interpreted with integrated conceptualization. The conceptualization of interpretive flexibility in the planning and designing of public spaces in the city is used as an interdisciplinary perspective in urban space design to open and discuss its connection and potential as an approach to strengthening social cohesion and inclusion. The general definition of flexibility is that it can create places with new forms of meaning and be used for different groups to strengthen its coherence and multidisciplinary inclusion in terms of design and planning of space and body. On this basis, the concept of flexibility is proposed as a principle in the context of design and planning due to its wide range of effects on background phenomena. The history of such a role can be seen in the diversity of users' needs. In such a way, it is impossible to express the specific time and area of the need to pay attention to this concept. This is in line with Oldenburg's theory of "social public spaces," in which being in public space, communicating with people and the environment through observing the streets, sidewalks, squares, and parks of the city is a necessary step for people as a part of their social life. The meaningfulness of the design of the artificial environment was considered. In any case, in the contemporary era, on the one hand, at the same time as the quantitative and qualitative increase of human environmental awareness, there is no longer any phenomenon in the eyes of contemporary man arising from a unique aspect and range of factors. On the other hand, his life needs in the individual and collective dimensions have seen a high diversity, which has led to the formation of multiple semantic domains of past flexibility. The meaning of flexibility in such an interdisciplinary platform and basic design refers to the concept of understanding and responding quickly and efficiently to environmental changes. Such a holistic definition for this broad field of environmental design means the implicit acceptance of the role of scale in the meaningful domain of these concepts. On a macro scale, it means making design options to increase the presence, participation, and power of choices of users of the environment in participatory urban planning and design methods, and on a small scale, it means making design options to increase spatial quality and, as a result, the quality of activities. The daily activities of environmental users are through selection against the "dominant space." Flexibility at different scales is crucial for dimensional optimization, shaping, and structuring spatial features, leading to improved performance of space components and spaces. The development of the concept of "flexibility" from various studies in metropolitan to micro scales, such as interior architecture, allows it to pass the discourse of responsiveness to provide a broad approach to environmental design in which different values, interests, and priorities are prioritized. As a result, the issue of flexibility in environmental design has been raised as a multi-dimensional field in the design and planning of the basic environment. The breadth and complexity of this concept have made the researchers of this field deal with it in one or more ways, and it has been avoided to provide a comprehensive framework about the nature and structuring processes. The current research presents a structured view of flexibility in architecture and urban planning with an environmental approach.   Methodology The methodology to achieve this goal is to use the macro research method and achieve a comprehensive framework by combining categorized interpretations. In such a way that by sorting and categorizing these concepts and bases in a new way, he has found a new level of theoretical findings, which will be a suitable answer for the gaps in scientific knowledge and scientific methods created in this field. In this context, the research method "thematic analysis" has been used with a qualitative approach and the use of library resources. Also, to overcome the breadth and complexity of these concepts and the multi-layer networking of concepts in this research method, artificial intelligence has been used in MAXQDA research assistance software.   Results and discussion In the meantime, attention should also be paid to the fields of influence and application of the results of this research because designers refer to flexibility as the creator of environmental qualities, including dynamism. Also, since flexibility, along with the principles of readability and adaptability, affect the lifestyle and behavioral patterns of the audience of environmental design in architecture and urban planning, it will also be effective in dealing with the challenge of complexity in environmental design factors. One of the key questions for achieving research goals on this issue is how flexibility in environmental design impacts the relationship between flexibility and scale.   Conclusion The most important finding of this research suggests that first, it requires a focus on the conditions under which the processes of perceiving human abilities and discovering the needs of the human audience can manifest. The theoretical framework arises from a comparative approach between design disciplines. These conditions are independent of the final state of the design product, and strengthening the environmental capacities will lead to a direction and an area that includes environmental flexibility. By responding to new situations, the construction of the space and the body within a space building can be adapted to various configurations. Even though the environment may remain constant, the designed place will continue functioning as a strong living system over time.  It also seems that the nature of issues related to flexibility has complexity. Considering that the quality of flexibility in urban planning and architecture is significant in multilevel and multifaceted scales from micro to macro, it is important to pay attention to the scale of different variables. In order to reduce this problem, the consistency and adjustment of the scale of the variables measured in a specific analysis should be considered in the first step.   Funding There is no funding support.   Authors’ Contribution All of the authors approved the content of the manuscript and agreed on all aspects of the work.   Conflict of Interest Authors declared no conflict of interest.   Acknowledgments We are grateful to all the scientific.

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Author(s): 

Fazel Zahra

Issue Info: 
  • Year: 

    2023
  • Volume: 

    23
  • Issue: 

    4
  • Pages: 

    563-568
Measures: 
  • Citations: 

    0
  • Views: 

    43
  • Downloads: 

    0
Abstract: 

Studying of megnetohydrodynamic waves in solar magnetic structures such as coronal loops, spicules, etc. can be very important for investigating the problem of heating the sun’s outer atmosphere. For this purpose, a magnetic flux tube was considered in the presence of steady flow and sheared magnetic field in a stratified atmospheric layer. The Transition Region is a boundary layer between the solar chromosphere and the corona, which has very rapid changes in temperature and density. The effect of the Transition Region on the damping of Alfven waves and temperature changes with height were applied in the assumed flux tube. The Cartesian two-dimensional model was used to solve the magnetohydrodynamic equations, and the results were obtained from the damping in the form of graphs of temporal and spatial changes of the perturbed velocity and magnetic field. The graphs showed that the damping of Alfven waves is more visible with time than with space, so the more rapid the damping occurs, the more energy will be transferred to the corona.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2024
  • Volume: 

    15
  • Issue: 

    1
  • Pages: 

    199-182
Measures: 
  • Citations: 

    0
  • Views: 

    50
  • Downloads: 

    28
Abstract: 

We conducted this study in the Agogo Traditional Area of the Ashanti Region of Ghana where there are numerous cases of conflicts between crop and animal farmers as a result of insufficient pasture for livestock, especially during the dry seasons. This has drawn the attention of various stakeholders in agriculture to the need for supplement feed through pasture establishment. The study examines farmers’ perception and the financial viability of pasture establishment for small ruminant production. The specific objectives of the study are as follow: to identify the cost and returns for the establishment of an acre of pasture, to assess the financial viability of pasture establishment on ‘cut and sell’ basis, to investigate farmers’ perception of pasture establishment for cattle production, to conduct a SWOT analysis of the establishment of pasture in Agogo. The study purports to analyze in detail, farmers' perceptions about the nature of the proposed 'Fodder Bank' policy and its likely effect on crop and livestock production, and whether the proposed policy could generate adequate monetary returns to induce its adoption at the farm level. The study seeks to provide evidence in support of SDG goals 2 (Zero hunger) and 12 (Responsible consumption and production) of the 2030 agenda for sustainable development. To the authors' best of knowledge, this is envisage to provide valuable information to support policy initiatives intended to tackle the root cause of farmer-herder conflicts. The Asante Akim North Municipal is one of the 27 administrative Districts in the Ashanti Region. Its capital is Konongo- Odumasi. The population for this study comprises livestock and crop farmers in Agogo. Asante Akim North Municipal was purposively selected for the study because it is noted for its agrarian abilities and massive production of food in the Ashanti Region. The multi stage sampling was employed in this study. At the first stage, Asante Agogo traditional area was selected purposively due to the fact that majority of the inhabitants engage in agricultural activities (GSS 2010). At the second stage, three communities in Agogo namely, Hwidiem, Ananekrom and Bebuso were selected purposively. At the third stage, quota sampling was used to obtain a specific number of farmers from each of the three communities to sum up to 150 respondents as shown in table. Simple random sampling technique was then used to engage the selected farmers in these communities. A sample size of 150 respondents were obtained using the Slovin’s formulae which is a scientific method of obtaining the sample size for a given population. Structured questionnaires consisting of open and close ended questions were used to gather primary data from respondents through face-to-face interviews. Interviews were conducted using the local dialect mostly to enhance communication and to clear all language barriers but English was used where the respondents could give accurate answers in English Language. Data per the questionnaires from respondents were concerning their perception of pasture establishment and the assessment of the strengths, weaknesses, opportunities and threats of pasture establishment. Secondary data was sought from books, journals, dissertations and the internet. Useful and relevant information on the appropriate materials and their costs for establishing pasture was also obtained from the Agogo MoFA office, and the KNUST Department of Animal Science. Descriptive statistics such as percentages, tables and means were used to analyze the socio-economic characteristics of respondents. It was revealed in the study that majority of crop farmers have had their crops destroyed by ruminants especially cattle at least once. Additionally, the study showed that pasture establishment is one way through which crop farms destruction by livestock can be prevented as about 99% of farmers responded in the affirmative. The results for the financial viability of the venture under the assumptions used gave relevant results with BCR of 1.18 and NPV of GHC 3,160. The Internal Rate Return of the venture is estimated at 40.1% and a Pay Back period of 2.61 years. Therefore, it will be economically prudent for investors to commit resources towards establishing pasture. The perception index for commercial, economic and financial concerns of pasture establishment was 3.7 which is skewed toward agree. The statement that had the highest positive perception index was about the fact that pasture establishment will increase the quality of meat. This implies that respondents perceive that the commercial, economic and financial results of pasture establishment will be positive. The perception index for the social category was 3.66. The statement with the highest positive assertion by respondents is the fact that pasture establishment will help control the movement of animals. The perception index of 3.66 which is skewed towards agree means that pasture establishment will attract the support from the community and also bring more benefits to the society. In the category of technical concerns of pasture establishment, the overall perception index for this category is 3.15, which means that the respondents perceive they have a fair technical know- how concerning pasture establishment even though the venture requires technical know-how. In the category of institutional concerns, support and involvement in pasture establishment, the statement with the highest perception index is that MoFA will support farmers with the necessary resources in its capacity. With reference to the chi-square test, the study can conclude that there is a significant relationship between the type of farmer and the perception that support can be drawn from farmer-based associations, and the perception that pasture establishment will increase livestock production as well as the general sales of farmers. Lastly, the study revealed that there is a significant relationship between the educational background of the farmer and the perception that it is not difficult to select planting materials for pasture establishment. Farmers in Asante Akim Agogo should adopt the establishment of pasture since it is financially viable. The establishment of pasture in Asante Akim Agogo should be encouraged since it has the potency to reduce the farmer - herder conflicts and ensure food security. For successful pasture establishment, technical know-how is essential.

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Issue Info: 
  • Year: 

    2023
  • Volume: 

    8
  • Issue: 

    2
  • Pages: 

    91-101
Measures: 
  • Citations: 

    0
  • Views: 

    28
  • Downloads: 

    1
Abstract: 

Background: The nutritional Transition observed worldwilde is linked to cardiovascular diseases. This study assessed the level of nutritional Transition and its implications in the occurrence of cardiometabolic risk factors among populations living in the Far North Region of Cameroon. Methods: A cross-sectional, descriptive, and analytical study was conducted during November 2020 recruiting 350 Cameroonians of both genders aged 18 years and above in urban (Maroua), semi-urban (Kaélé) and rural (Midjivin) areas. Demographic, socioeconomic status and food habits were assessed through an interview. Anthropometric (weight, height, body mass index: BMI) and blood pressure were measured. A fasting blood sample was collected for lipid profile. Results: Mean age was higher in Kaele (44.99±16.55 years) and Midjivin (47.23±18.21 years). Urban residents of Maroua (23.38±4.80 kg/m2) and Kaele (23.13±5.01 kg/m2) had the highest BMI. Rural dwellers exhibited elevated cholesterol (220.30±70.40 mg/dL) and triglycerides (120.52±62.64 mg/dL). Diastolic blood pressure and heart rate increased significantly with urbanization. Low fruit and vegetable consumption, high alcohol intake, and low physical activity were observed in all three areas. An increased frequency of abdominal obesity, high blood pressure, hypercholesterolemia and hypertriglyceridemia were noticed in all participants. Midjivin inhabitants showed behavioral changes closer to those in Maroua, while those of Kaele had a slower rate of nutritional Transition.Conclusion: People living in rural, semi-urban, and urban areas have stated the nutrition Transition process in this part of the country. Thus nutritional education needs to be reinforced for a better prevention of nutritional-related morbitidies and mortalities drived by urbanization.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    52
  • Issue: 

    2
  • Pages: 

    67-82
Measures: 
  • Citations: 

    0
  • Views: 

    170
  • Downloads: 

    16
Abstract: 

Identifying the constraining factors of production and yield gap is very important. Therefore; this research was performed to identify the production constraining factors of local rice cultivars. All management practices from nursery preparation to harvesting stages for 100 paddy fields of local rice cultivars were recorded through field studies, in Sari, from 2015-2016. In the CPA, the actual and calculated potential yield were 4495 and 5703 kg/ha, respectively and the gap was 1221 kg/ha. The yield gap caused by number of top-dressing variables was 324 kg/ha, equal to 27% of the total yield gap. The yield gap related to previous year of legumes cultivation was 218 kg ha-1, equal to 18% of the total yield variation. Among the 10 variables entered in the CPA model, the effects of top-dress fertilizer application and its application frequency and foliar application were remarkable, which could compensate a significant part of the yield gap (444 kg/ha, 37% of total) in the farmers’ fields by managing these variables. According to boundary line analysis (BLA) finding, actual yield mean on the basis of optimal limit related to 12 variables under study was 5369 kg/ha, with 881 kg/ha yield gap . Mean relative yield and relative yield gap for 12 variables (transplanting date, seedling age, number of seedlings per hill, planting density, nitrogen and phosphorous per hectare, nitrogen before transplanting, harvesting date, lodging problem, pest problem, diseases problem and weeds problem) were 83.64 and 16.35 kg/ha, respectively. Based on the finding, it can be stated that the model precision is appropriate and can be applied for both estimation of the quantity of yield gap and determining the portion of each restricting yield variables.

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Writer: 

JAHANGIRI M.

Issue Info: 
  • Year: 

    2004
  • Volume: 

    9
Measures: 
  • Views: 

    141
  • Downloads: 

    0
Abstract: 

THE HYDRODYNAMICS OF THE FLOW IN STIRRED-TANK REACTORS, I. E. VELOCITY PROFILES, STRESS FIELDS, TURBULENCE CHARACTERISTICS AND SO ON, ARE ESSENTIAL FOR THE CONFIDENT DESIGN OF MIXING TANKS. FLUCTUATION TANGENTIAL AND RADIAL VELOCITIES WERE MEASURED USING A TWO COMPONENT LASER DOPPLER ANEMOMETRY (LDA) SYSTEM FOR A TYPICAL RUSHTON TURBINE IMPELLER. THE WORKING FLUIDS WERE DIFFERENT CONCENTRATIONS OF POLYACRYLAMIDE (PAA) SOLUTIONS WITH RHEOLOGICAL PROPERTIES TYPICAL OF THOSE FOUND IN POLYMER PROCESSES. IT IS SHOWN THAT THE CORRELATIONS FOR FLUCTUATING VELOCITIES IN NEWTONIAN FLUIDS DO NOT APPLY TO THE CASE OF VISCOELASTIC LIQUIDS. NEW CORRELATIONS ARE GIVEN IN THE LOWER PART OF THE Transition Region, I. E. 30< RE< 2000, FOR FLUCTUATING TANGENTIAL AND RADIAL VELOCITY COMPONENTS VALUES ALONG THE CENTER LINE OF THE IMPELLER TIP.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

JAHANGIRI M.

Issue Info: 
  • Year: 

    2007
  • Volume: 

    16
  • Issue: 

    11
  • Pages: 

    731-739
Measures: 
  • Citations: 

    0
  • Views: 

    358
  • Downloads: 

    381
Abstract: 

Velocity profiles are helpful for the confident design of mixing tanks in the Transition Region. In this article, velocity profiles for helical ribbon impeller have been studied using laser Doppler anemometry for viscoelastic liquids with rheological properties typical of those found in polymer processes. Local tangential and radial velocities were measured at radial positions on a horizontal plane passing through the middle of the helical ribbon impeller. New correlation is suggested for dimensionless local tangential velocity profiles in the Transition Region, i.e. 70<NRe<6700. Experimental results show that the magnitudes of dimensionless radial velocities are much less than dimensionless mean tangential velocities such that no considerable radial flow could be detected.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2023
  • Volume: 

    10
  • Issue: 

    1
  • Pages: 

    123-138
Measures: 
  • Citations: 

    0
  • Views: 

    35
  • Downloads: 

    6
Abstract: 

The similarities between Ca and x-ray jets suggest that their formation mechanism should be the same. Surges are almost cool plasma jets and are usually observed in Hα at ground-based observation, space observations also detect Surges. The structure and movement of the observed surges and jets necessitate a reconnection framework in which magnetic tension and the release of twisted energy contribute significantly. Convincing indications of reconnection are offered by whip-like movements, and the rotational behavior of the surges arises as an outcome of the relaxation of reestablished magnetic twist. The IRIS spectra spicules to determine one of the factors affecting the production and feeding of solar winds. Jets and spicules have been considered by examining several raster frames from the Regions of the Sun. The characteristics of spicules, such as the rotational velocity of each spicule concerning the central axis of the spectrum , were computed using the output of the Doppler map. Then, using the Mg II spectrum simultaneously, Doppler maps for specific index samples were created at various speeds. Based on the results, a speed of 30 km/s was demonstrated.Our investigation into spicules unveiled a distinctive type that deviates from prior observations regarding speed, angle, and direction of movement. These spicules appear to result from vortical movements, which could also contribute to the propagation of Alfvén rotational waves and the transfer of energy to the Sun's upper atmosphere. In this study, it is essential to recognize that rotating spicules represent minute structures observable in exceedingly high-resolution imaging.

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