The Comparative Study of Ranking System of Islamic Countries Universities and National Ranking of Universities in Iran Using the Most Famous Ranking Systems in the World

This research is aiming at a comparative study of Islamic countries university`s ranking system and Iran`s universities` national ranking system with the most famous ranking system in the world which are as Academic Ranking of World University (ARWU), The Times Higher Education World University Rankings (THE), The Quacquarelli Symonds World University Rankings (QS), The U.S. News rankings (USN), Center for World University Rankings (CWUR). In this research, the criteria and indicators of each of the five higher education ranking systems are described based on the two ranking systems of ISC and National Ranking of universities of Iran and using George Bradley's comparative analysis and considering the list of top universities in the last update of the Internet portal by the date 05/09/2017. In this research, it is revealed that there is not any similarity between QS ranking system and ISC ranking system. However, based on the results, Iran and ISC ranking systems are mostly compatible with THE, from among the globally most famous ranking systems. Combining THE and Iran`s ranking systems could offer a far more global system which is capable of covering all aspects of ranking and universities` universal status. THE and ARWU can be named as the most complete combined systems, from among the global and most famous ranking systems, which can be used as a substitution for Iran`s ranking system

Assessment of the Inferior Mandibular Canal’s Position by Cone-Beam Computed Tomography

Objectives: It is important to know the exact location and anatomic variety of inferior alveolar nerve canal for different procedures of mandibular surgeries. The aim of the present study was to evaluate inferior mandibular canal’s anatomic position by Cone-beam Computed Tomography (CBCT).Methods: In a cross sectional study, CBCT were taken and assessed from 130 patients (260 semi-arch) referring to the radiologic department of Shahid Beheshti Dental Faculty. Three points including 1cm before mental foramen (point A), under second molar’s furcation (point B) and 1cm after mandibular foramen on the inferior alveolar canal (point C) were chosen. The canal diameter, length and the distance between the canal and inferior border of mandible were measured. SPSS version 19 software used for data analysis. T and variance tests evaluated the role of age, gender, canal length and jaw side.Results: Mean age of patients was 43.73±13.25. Canal length, 61.71 ± 4.95 ml and canal diameter was 2.94 ± 0.58 mm. The distance between the canal and the inferior border of mandible was 9.47 ± 2.23 mm. There was a significant difference in gender and age for all parameters. The distance between the canal and the inferior border in C point and at mental foramen in cases with short and long canal length showed a significant difference. (p≤0.012)None of the variables showed significant difference between right and left sides.Conclusion: The anatomic position of mandibular canal is related to gender and canal length, and independent to age and side

Effect of Slice Thickness on the Accuracy of Linear Measurements Made on Cone Beam Computed Tomography Images (InVitro)

Objective: Cone beam computed tomography (CBCT) is applied for the imaging of the maxillofacial and dental structures, particularly for surgical treatments and dental implants. The aim of this study was to assess the effect of slice thickness on the accuracy of CBCT linear measurements. Methods: In this diagnostic accuracy study, forty-two titanium pins with the same dimensions were inserted into seven dry sheep mandibles. The length of the pins before the insertion was carefully measured by a digital caliper, (0.01mm accuracy). Imaging of the mandible performed using CBCT New Tom VGi. After image reconstruction by NNT Viewer, linear measurements were made on cross-sectional slices (thicknesses of 0.125, 0.5, 1 and 2mm) by three radiologists. The accuracy of measurements assessed using descriptive indices and compared between different slice thicknesses by repeated measures ANOVA.Results: Repeated measures ANOVA showed a significant difference between different slice thicknesses (P=0.024). According to the least significant difference (LSD) test, the difference in absolute errors was significant in all thicknesses (P=0.024). Measurements at 0.125 mm thickness were significantly different from others, with a higher error rate (mean absolute error=0.17). Measurements at 0.5mm thickness showed a significant difference with those at 0.125 and 2mm (mean absolute error=0.15). Measurements at 2mm thickness were significantly different from those at 0.125 mm thickness (mean absolute error=0.13).The average error rate was lower in 2mm thickness and the measurements were more accurate.Conclusion: A statistically significant difference was seam between CBCT measurements and actual sizes in different slice thicknesses. The differences were below 1mm, and clinically acceptable

Numerical and Experimental Investigation on the Flow Separation Control of S809 Airfoil with Slot

A new flow control approach called split blade is applied on the S809 airfoil in the present study. S809 airfoil was investigated experimentally and numerically with different operating conditions including cascade without control, cascade with slots that generate jets with AOAs of 0 degrees, 10 degrees, 15 degrees and 20 degrees. Good agreement was obtained between the comparison of the experimental and numerical results. The results show that the separation area increases with increase of the AOA and the large separation area appears on the airfoil suction surface at AOA equal to 20 degrees. Numerical results show that the control method has little negative influence on the airfoil performance at small AOAs. Smaller vortices are filled with the large separated area which is divided by the jet generated by split when the AOA is 20 degrees. The analysis on the lift coefficient and drag coefficient shows that the flow is improved with the control. The lift coefficient and drag coefficient do not change in the comparison between the cases before and after control when AOA is 0 degrees and 10 degrees. However, the lift coefficient increases and drag coefficient decreases when AOA is 15 degrees and 20 degrees

Numerical study of the effect of adding corona discharge based on plasma actuator on flow control performance in a horizontal axis wind turbine with rough surfaces

The use of renewable energy has recently become very common in most countries of today's society. Among these renewable energies, wind energy is one of the most attractive methods of mechanical energy production, and different methods of flow control, including active, semi-active and passive, have been investigated by various researchers. To control the fluid flow in an active way on the wind turbine blade, the corona discharge actuator based on plasma is considered the most appropriate method to reduce the fluid flow separation on the wind turbine blade. In this paper, we present a numerical simulation to integrate active load control using a corona discharge based on plasma actuators over the roughness blade. Effects of roughness, actuators voltage and frequency on aerodynamics parameters such as separation point, lift and drag coefficients have been showed. Present results showed that, the lift coefficient increase with increase in the voltage and frequency of plasma actuators. Overall, using the roughness for outer surface of blade would decrease the critical pressure coefficient by approximately 50% compared to that for the smooth surface

Power Generation Enhancement of Horizontal Axis Wind Turbines Using Bioinspired Airfoils: A CFD Study

This research investigates the performance implications of employing a bioinspired airfoil (seagull’s wing cross-section) in horizontal-axis wind turbines. Specifically, we replaced the S809 airfoil from NREL Phase VI with an airfoil modeled after seagull wings. Initially, we calibrated four coefficients of the GEKO turbulence model for both the S809 and the bioinspired airfoil, utilizing experimental data. Subsequently, using the calibrated generalized k-ω (GEKO) model, we conducted a comparative analysis between the S809 and the seagull airfoils, revealing the considerable superiority of the seagull airfoil in terms of lift and drag coefficients. Furthermore, we numerically simulated the original NREL Phase VI turbine and a modified version where the S809 airfoil was replaced with the seagull airfoil using 3D computational fluid dynamics (CFD) with the airfoil-based-calibrated GEKO turbulence model. This investigation spanned a wide range of air speeds, including 7 m/s, 13 m/s, and 25 m/s. At these wind speeds, we observed a substantial increase in turbine power generation, with enhancements of 47.2%, 204.4%, and 103.9%, respectively. This study underscores the significant influence of nature’s designs in advancing energy extraction within industries, particularly within the wind energy sector

Multi-Megawatt Horizontal Axis Wind Turbine Blade Optimization Based on PSO Method

Blade optimization methods are crucial for wind turbine design. In this research, a new set of values for the parameters of the Particle Swarm Optimization (PSO) method is proposed, and its effects on the enhancement of the power generation of the NREL WP-Baseline 1.5 MW horizontal axis wind turbine are investigated. First, the PSO parameters are tuned, and the convergence speed and the optimal accuracy of the objective function are improved. Then, the Class/Shape Transformation (CST) method is employed, and an appropriate order of the shape function polynomial is selected. In the third step, the WP-Baseline 1.5 MW blade is optimized according to the tuned PSO parameters, and the airfoil is represented by CST algorithms. Later, a CFD model, including 37 million cells and an IDDES turbulence model, was validated and used for a comparison of the power generation of the original and optimized blades. The optimized blade produced more power for all wind speeds above 4.5 m/s, with a maximum of 13.8% at 10 m/s and +7.25% at the rated wind speed (11.5 m/s). It should be noted that since the algorithms, tunings, and techniques adopted in the present study were general, the presented method can be used as a systematic approach for the aerodynamics shape optimization of multi-megawatt HAWTs

A Comparative Semiology of Gholām-Hossein Sā'edi’s "Azā'dārān-e Bayal" and Franz Kafka’s "The Metamorphosis"

1. Introduction Comparative literature is the study of literary works of different nations in order to better understand these works. Such studies will enrich national literature because "scholars and researchers of comparative literature all agree that the primary purpose of comparative literature is to use foreign literature to enrich and enrich national literature."  (Neda, 2004, 25).     Gholam-Hossein Sa'edi (1936-1985) is one of the leading Iranian writers who has made remarkable works. Sa'edi narrates the fate of the inevitable contemporary man. This human lives in a backward society that is still far from reaching progress. The man who he describes is still embroiled in the superstitions and nonsense of such a backward society. The Mourners of Bayal, in fact is one of the most prominent and, as some critics say, the best forearm, depicts of such a society in its various dimensions. In a society which Sae’di describes, still prayer and cursing are the top tools for dealing with problems. Poverty has spread its ominous shadow over all aspects of this society, and robbery and looting is a clear sign of such a society that makes it more like primitive societies.    Franz Kafka (1883–1924), also is one of the world's greatest writers, owns valuable works that have been the subject of comparative reviews. Kafka deals with contemporary man in his stories. A man who brought civilization and progress to his loneliness and despair, along with this loneliness, in the world of Kafka's fictional characters.   2.  Methodology This study uses comparative method by using library research. This research tries to answer the following questons: Have Saedi and Kafka used similar symbols in the two works? What kind of symbols have Saedi and Kafka used in these two works? What are the similarities and differences between the symbols of these two stories?   3. Discussion Sa’edi uses symbols to instill a secondary concept in the story of The Mourners of Bayal. Kafka also has used symbols in the story of "Metamorphosis" to achieve this end. Studying these two stories reveals the similarities and differences in the way they are applied and the broad meanings that each writer intended. We have divided the symbols of these two stories into human, non-human (places and objects) and animal symbols.     Human symbols in the story of "The Mourners of Bayal " include arbāb (the master), maşdī eslām (Islām), müsorxe (red hair man), maşdī Hassan. In the stories of The Mourners of Bayal, the master is a symbol of "the establishment of a master system in the village" (cf: Shiri, 2014: 64). Sae’di does not create this fictional character, but the master is present in all stories, and the villagers perceive his heavy shadow in the context of the events.    One of the minor characters in The Mourners of Bayal ing Stories is maşdī eslām, who becomes the main character in some stories, including the eighth story. maşdī eslām is, in fact, intellectually different from the people of the village. He therefore, represents the class strata of society that have little difference in attitudes and beliefs with the lower classes of society. Just like the story of Kafka, this story begins with a shocking incident. maşdī Hassan has gone to work in the village of Sayyed Abad. His cow is dead last night and the villagers do not want to give this bad news to maşdī Hassan. So they throw the carcass into the well and decide to tell maşdī Hassan that the cow has fled and sent one of the locals to find it. The metamophisis of maşdī Hassan in this story is a symbol of the fading, transformation and alienation of human beings in backward societies. It should also be noted that maşdī Hassan 's metamophisis is a spiritual rather than a physical transformation (in contrast to the metamophisis in Kafka's story).     Müsorxe (red hair man) is another human symbol of this story. In the seventh story, the red hair man is the main character of the story. He suffers from severe hunger and insatiability. Everything even swallows junk. His metamophisis of as a rat is a physical metamophisis. A transformation that is lurking in every village. In fact, "the overeating insanity is a sign of hunger and excessive hunger for people who simply do not get it" (Taslimi, 2009: 121).     Human symbols have also been used in the Kafka’s Metamorphosis. Father, mother and sister-in-law are human symbols of this story. Father of Gregor is a minor character in the story. He is a violent, bully, tyrant, and plays a leading role in one of the story's events - throwing apples at Gregor.     Gregor's mother is a mild-tempered human being in this story, always trying to mediate and calm things down. Grigor's mother's personality is undoubtedly inspired by the true character of Kafka’s mother. "Kafka’s mother was a gentle and gentle woman and played a role of reconciliator at home" (Meghdadi, 2017: 15).     Gregor's sister (Grete) first treats Gregor with embarrassment. She picks up food for him, and later, when Gregor turns to eating leftovers, she takes the leftovers him. She plays the violin, and Gregor provides the necessary equipment for her music classes when he is not ousted. The night that Grete plays the violin, Gregor is affected by the sound of her violin, and as he exits his room he goes to his sister, angering her. The incident causes a change in her sister's characteristics. Afterwards, Grete becomes Gregor's main enemy, trying to persuade her parents to get rid of Gregor - or this ugly creature.     Human symbols of The Mourners of Bayal Stories include Bayal village, Poros, Khatunabad, the city, as well as things like generator and maşdī eslām and the bell.     Bayal is a village with naive and superstitious people. Sa’edi describes the village with a dark, sad atmosphere where death always flows. The village of Bayal represents a community in which Saad lived.    The inhabitants of Poros live near Bayal. They are known for theft and looting. The terror they create in their theft, looting and assaults is always evident in the village of Bayal. In fact, if Bayal is an icon of Iran, "Poros can also be a representation of ... England ... and America ..." given the background of Iran's historical and political developments from the Qajar period until the book was written. (cf: 2014: 66).    Khatun Abad is a village near Bayal. The inhabitants of this village, although not as vicious as inhabitants of Poros, are sometimes vicious, but sometimes commit minor evils against the villagers. Bayal is a symbol of Iran, but Khatun Abad is undoubtedly a symbol of the Russian government.       In The Mourners of Bayal, the city is described as an ideal place. Rural people often seek refuge in the city in order to free themselves from village problems.      Generator is one of the non-humane symbols (objects) in Bayal's mourners. In the sixth story, several villagers return to the city in a strange way, a generator falling from the truck of American soldiers in the middle of the road. This object is not familiar to the villagers and because they hear a sound like crying inside it or imagine that it is the sound of crying, they take it to the village and make it a shrine. In fact, this object in the story symbolizes the ignorance and ignorance of the villagers.     Other non-human symbols (objects) in the story are maşdī eslām’s instrument, which he sometimes makes people happy. His instrument must be interpreted as a symbol of something in which he has to bind himself to the ordinary people.      Sa'adi uses the bell symbol in " The Mourners of Bayal". The sound of the bell rings everywhere. Especially when the presence of death is more felt.     As noted above, non-human symbols (places and objects) are also used in the story of " The Metamorphosis". Non-human symbols in Kafka's "Metamorphosis" story include Gregor's room, a beautiful wall-mounted picture board, room furniture, apples, and a violin instrument.      Gregor is forced to take refuge in his own room after his demise. The room actually becomes Gregor's world, and in a sense, symbolizes his isolation. It is a place where Gregor has to be imprisoned for being excluded from society. The photo frame is, in fact, a symbol of Gregor's affinity for sexuality, and the only attachment and interest he is unwilling to lose. In one scene of the story, Gregor comes out of his room and the father sees it as an evil sign from him and attacks Gregor with apples from the fruit bowl.     In "The Metamorphosis", Kafka also symbolizes Gregor's sister's violin as a secondary concept. The music here is a symbol of everything that links Gregor to his time as a human being and stimulates his human emotions. In both stories, animal symbols are used. In the story of Bayal's mourners, Sae’di only uses the symbol of Abbas's dog to induce what he intends to do. In fact, the dog in this story symbolizes the sacrifice made by those around him, and his fate is nothing but death and destruction. The animal symbols of Kafka's "The Metamorphosis" story are only limited to the creature that Gregor has become. In fact, the most powerful symbol of this story is the symbol of being depicted as an insect, and most of the meaning of the story is borne by it. Gregor's metamorphsis in this story is physical, not spiritual.   4. Concluson This research concluded that these writers both used human, non- human (places and things) and animal symbols in these stories. Kafka and also Sā'edi wanted to transmit the deep concepts of the description of their era by these symbols. The character of Franz Kafka’s “The Metamorphosis” and Maşdi Hassan in Sā'edi’s story are the most prominent symbols of these stories. We have explored the symbols of these two stories comparatively. Sa’edi and Kafka both are writers who have considered symbols in their works. Both depict the status of human in their societies, but there is a difference. The human who Sa’edi depicts that is rural human who has problems such as ignorance, superstition and poverty; but Kafka depicts human who has nothing solitude and lack of identity in the tumult of progress and modernization. Sa’edi in the stories of “The Mourners of Bayal” has used human, non-human and animal symbols. The human symbols of these stories are: arbāb (the master), maşdī eslām (Islām), müsorxe (red hair man), maşdī Hassan. Kafka also, has made Gregor Samsa’s father, mother and sister as the human symbols. The non-human symbols of Sa’edi’s stories are Porus and Khatun Abad villages, power alternator, maşdī eslām’s musical instrument and bells. Also, in Kafka’s story, we can find non-human symbols such as panel, clock, home furniture, apples and violin. In 5th story of “The Mourners of Bayal” there is an animal symbol which is a dog belongs to Abbas. In the Kafka’s “The Metamorphosis”, also, "monstrous vermin" is the only animal symbol

A simplified tempo-spatial model to predict airborne pathogen release risk in enclosed spaces: An Eulerian-Lagrangian CFD approach

COVID19 pathogens are primarily transmitted via airborne respiratory droplets expelled from infected bio-sources. However, there is a lack of simplified accurate source models that can represent the airborne release to be utilized in the safe-social distancing measures and ventilation design of buildings. Although computational fluid dynamics (CFD) can provide accurate models of airborne disease transmissions, they are computationally expensive. Thus, this study proposes an innovative framework that benefits from a series of relatively accurate CFD simulations to first generate a dataset of respiratory events and then to develop a simplified source model. The dataset has been generated based on key clinical parameters (i.e., the velocity of droplet release) and environmental factors (i.e., room temperature and relative humidity) in the droplet release modes. An Eulerian CFD model is first validated against experimental data and then interlinked with a Lagrangian CFD model to simulate trajectory and evaporation of numerous droplets in various sizes (0.1 μm–700 μm). A risk assessment model previously developed by the authors is then applied to the simulation cases to identify the horizontal and vertical spread lengths (risk cloud) of viruses in each case within an exposure time. Eventually, an artificial neural network-based model is fitted to the spread lengths to develop the simplified predictive source model. The results identify three main regimes of risk clouds, which can be fairly predicted by the ANN model.Peer reviewe

A simplified model to estimate COVID19 transport in enclosed spaces

Airborne pathogen respiratory droplets are the primary route of COVID19 transmission, which are released from infected people. The strength and amplitude of a release mechanism strongly depend on the source mode, including respiration, speech, sneeze, and cough. This study aims to develop a simplified model for evaluation of spreading range (length) in sneeze and cough modes using the results of Eulerian-Lagrangian CFD model. The Eulerian computational framework is first validated with experimental data, and then a high-fidelity Lagrangian CFD model is employed to monitor various scale particles' trajectory, evaporation, and lingering persistency. A series of Eulerian-Lagrangian CFD simulations is conducted to generate a database of bioaerosol release spectrum for the release modes in various thermal conditions of an enclosed space. Eventually, a correlation fitted over the data to offer a simplified airborne pathogen spread model. The simplified model can be applied as a source model for design and decision-making about ventilation systems, occupancy thresholds, and disease transmission risks in enclosed spaces.Peer reviewe