295 research outputs found
Proper Motions of Sunspots' Umbral Dots at High Temporal and Spatial Resolution
To deepen the analysis of the photometric properties of the umbra of a
sunspot, we study proper motions of small features such as umbral dots (UDs)
inside a single sunspot observed by the Solar Optical Telescope of Hinode close
to the disk center. We consider horizontal flows with high precision and
details to study the transient motion behavior of UDs in short time intervals.
Blue continuum images were first deconvolved with the point-spread function,
such that the stray light is precisely removed and the original resolution is
improved. Several images were co-added to improve the signal-to-noise ratio,
keeping a reasonable temporal resolution and checking that the results are
reproducible. The Fourier local correlation tracking technique is applied to
the new corrected time sequence of images, and horizontal velocity maps were
obtained both for the whole umbra and for a high-resolution small region of the
umbra to study the smallest details of the velocity fields. We used two
different Gaussian tracking windows (0.8arcsec and 0.2arcsec), which reveals
two types of horizontal motions for umbral features. First, a global inner
penumbra and peripheral umbra inward motion directed to the central parts is
revealed as an overall proper motion of bright peripheral fine structures.
Second, motions matching small cells inside the darkest parts of the umbra with
apparent sink and source areas are revealed, suggesting possible upflows and
downflows appearing in different bright and dark locations without a definite
answer regarding their brightness identification with a convective or a buoyant
cell
Study of the effect of family patterns Style on opium abusers, cigarette abusers and normal group
AbstractThe Goal of present study was examining the effect of family Parents Style on opium abusers, cigarette abusers and normal group.The sample group included 120 (opium abusers, cigarette abusers, normal group). Samples selected from different area of Shiraz, Iran. Revised version Schaefen Family Patterns Style Questionnaire was used. By using one way ANOVA the effect of patterns Style on groups, were verifies.Cronbakh alpha coefficient was acceptable. There is a significant difference between groups
The effect of a selected home-based exercise program by consuming coffee on blood lipid profile of inactive middle-aged men in COVID-19 pandemic condition
The purpose of this study was to examine the effect of 8 week a selected home based exercise program by consuming coffee on blood lipid profile of inactive middle-aged men in pandemic COVID-19 condition. The present study is a semi-experimental methodology and 44 middle-aged men with fatty liver were randomly divided into four groups of 11 cases: home-based exercise, coffee, home-based exercise + coffee, control. Blood test was used to measure blood lipid profile. The combined home-based exercise intervention was performed for 8 weeks, three sessions and 60 minutes per session. Coffee intervention consumed 10 grams of coffee per every other day. The results showed that weight, body mass index, LDL cholesterol, total cholesterol and triglyceride decreased significantly after eight weeks of training in all three experimental groups and HDL cholesterol increased significantly (p < .05). It seems that performed combined home- based exercise and in combination with coffee consumption can be effective in improving the blood lipid profile of inactive middle-aged men in quarantine and paired COVID-19 conditions and prevent liver damage
New Media and Ideology: a Critical Perspective
Media is considered as one of the ideological apparatuses. This research is based on the question in parallel of enhancing technology and the formation of new media, as well as change passive audience into the active user, can these media still be called ideological? If so, the question is that how does the new media, despite the adaptation of interaction from the internet, find the ideological function? This paper discusses the role of the concept of the ideology for understanding social media critically. This study based on Althusser's definition of ideology and Habermas's theory about the public sphere creates consultative democracy led it to evaluate new media, their behavior and practices. The paper was developed based on a qualitative approach and descriptive-analytical method. As a result, new media owners are looking to create a two-tier Internet in which commercial content is more important than public content. Commercial content is managed by the ruling power and is governed by an ideology, which is the ideology of the ruling class. On the contrary, public content is controlled by media owners and contains a variety of ideologies that carry different ideas and meanings. The contemporary media system, through its ownership has divided media audiences into smaller groups (specific audiences), and has severely restricted fair access and participation in the public sphere, so that the ideological aspect of new media remains unchanged, but it emerges in the new shapes
Effects of different geometric patterns on free form gridshell structures
Gridshells are commonly known as structures with the shape and rigidity of a double curvature shell consisting of a grid, not a continuous surface. In recent decades, these structures have attracted significant attention. The impact of various geometric patterns on free form gridshell structures is investigated here to demonstrate the necessity of collaboration between structural and architectural characteristics in enhancing structure efficiency. To that goal, a framework is proposed where three shells are first designed, and then six geometric patterns are formed on them. The main factors for evaluation of gridshells are decreasing the steel weight as an economic index and decreasing the displacement as a structural index, also, finite element method is used for structurally analyzing the gridshells, and the generated gridshells are compared to each other based on the mentioned indices. For the optimization process, an approach is suggested to find the most optimum gridshell, then numerical results show the efficiency of the proposed alternative approach
The Role of Jewish Messianism in Israel's Hostile Foreign Policy towards the Islamic Republic of Iran
Messianism is one of the most important concepts in Judaism. The Zionist movement succeeded in establishing a Jewish state in the land of Palestine based on the changes it made to the traditional meaning of this concept. On the other hand, Messianism is the only common concept on which all the various Jewish sects agree. Accordingly, after the establishment of the Jewish state in 1948, Messianism entered into all aspects of Israeli domestic and foreign policies. Also, simultaneously with the Islamic Revolution in Iran, right-wing and religious groups came to power in Israel in 1977 after thirty years. One of the common traits of rightists is that they are Messianic; thus, the variable of Messianism in the foreign policy of Israel towards Iran became an objective factor and appeared in a hostile manner. Therefore, the present article uses the theory of constructivism, which in addition to material issues such as power, also considers immaterial variables such as religion to be important in international relations; it seeks to answer the question of how Jewish Messianism led Israel to pursue a hostile foreign policy toward the Islamic Republic of Iran
Comparison between Low Flow Indices Using FL Approach and Low Flow Frequency Curve (A Case Study of Gharesou River Catchment)
Selection of low flow is necessary for water resource management, water supply planning, and watershed ecosystem restoration. In this study, FL approach was used, which is based on minimum flows and flow duration curve (Q80) categories. This approach was compared with the conventional 7Q10 approach used in low flow selection. For this purpose, the daily flow series from Gharesou catchment was applied. Low flow frequency analysis related to 7Q10 approach was done by fitting various distribution functions and using three frequency software, including HYFA, SMADA, and Easy fit. The results of both approaches show that low flows increased as time elapsed and the recurrence probability of low flow increased while the recurrence interval of low flow decreased as time elapsed. In addition, a low flow decline from 1971 to 2000 observed as 1.57 m3/s and 2.46 m3/s for 7Q10 and FL approaches respectively. The 7Q10 approach lead to selecting extremely low flows (approximately zero). The FL approach used in this study, could result in selecting low flows, considering role of the environment and minimum flow to protect the ecosystem of the catchment
Numerical investigation of mixing by induced electrokinetic flow in T-micromixer with conductive curved arc plate
Mixing is essential in microdevices. Therefore, increasing the mixing efficiency has a significant influence on these devices. Using conductive obstacles with special geometry can improve the mixing quality of the micromixers. In this paper, a numerical study on the mixing caused by an induced-charge electrokinetic micromixer was carried out using a conductive plate with a curved arc shape instead of a conductive flat plate or other non-conductive obstacles for Newtonian fluids. This study also explored the effect of the different radius curves, span length, the number of curved arc plates in the channel, the pattern of arrangement, concavity direction, and the orientation angle against the flow on the mixing. Furthermore, the efficiency of the T-micromixer against a flow with a low diffusion coefficient was investigated. It should be noted that the considered channel is symmetric regarding to the middle horizontal plane and an addition of flat plate reflects a formation of symmetric flow structures that do not allow to improve the mixture process. While an addition of non-symmetric curved arc plates al-lows to increase the mixing by creating vortices. These vortices were created owing to the non-uniform distribution of induced zeta potential on the curved arc plate. A rise in the span length of the curved arc plate when the radius was constant improved the mixing. When three arc plates in one concavity direction were used, the mixing efficiency was 91.86%, and with a change in the concavity direction, the mixing efficiency increased to 95.44%. With a change in the orientation angle from 0 to 25, the mixing efficiency increased by 19.2%
Modelling of Queue Length in Freeway Work Zones – Case Study Karaj-Tehran Freeway
In this study, the traffic parameters were collected from three work zones in Iran in order to evaluate the queue length in the work zones. The work zones were observed at peak and non-peak hours. The results showed that abrupt changes in Freeway Free Speed (FFS) and arrival flow rate caused shockwaves and created a bottleneck in that section of the freeway. In addition, acceleration reduction, abrupt change in the shockwave speed, abrupt change in the arrival flow rate and increase in the percentage of heavy vehicles have led to extreme queue lengths and delay. It has been found that using daily traffic data for scheduling the maintenance and rehabilitation projects could diminish the queue length and delay. Also, by determining the bypass for heavy vehicles, the delay can be significantly reduced; by more than three times. Finally, three models have been presented for estimating the queue length in freeway work zones. Moreover, the procedure shown for creating a queue length model can be used for similar freeways
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