فهرست مطالب علیرضا داوری

Composite materials are of great interest due to their exceptional strength, hardness-to-density ratio, high corrosion resistance, and low weight. One of the suitable methods for making composite pipes is using the extrusion process. Extrusion is a plastic deformation process that due to the compressive state of stress in extrusion, materials with low plasticity can be formed by this method. This article deals with the experimental-numerical investigation of extrusion, from various methods of forming process. Extrusion is done on a composite tube using aluminum and magnesium alloys. Aluminum is used due to its strength compared to high weight, excellent malleability, and magnesium due to the lightest structural metal, the lowest density among structural materials, machining, welding and casting capabilities, as well as high specific strength. The mentioned process was tested at different extrusion ratio, temperature and speed, and the effect of different process parameters on the properties of the extruded product was investigated. Then the process was simulated in the software and the experimental results obtained from the laboratory work and the numerical results obtained from the simulation were compared and validated with each other and the error percentage between the graphs of the experimental and numerical results was examined.

In this paper, two predictive control methods for dual output multilevel rectifier are compared. The investigated structure is a seven-level PUC rectifier, which was selected based on high reliability and low cost. Increasing the number of input voltage levels helps to reduce the amount of harmonics and consequently reduce the size of power filters. On the other hand, current conduction in this converter is performed continuously and the problems of current discontinuity such as complexity in analysis and the requirement to use large induction filters on the DC side are solved. First, the design is accomplished based on the FCS-MPC method and two different output voltages with ratios of 1 and 3 are obtained. Also, the control of output DC voltages and unity input power factor is well provided. Then, to achieve better stability, the MPC method based on Lyapunov theory has been utilized. In this method, the target variables are defined in the Lyapunov function and the cost function is derived from the same Lyapunov function. The advantages of this approach compared to the conventional MPC method are no need for gain adjustment, easier implementation and fewer sensors (the load current is estimated using the PUC7 rectifier mathematical model). The simulation of both FCS-MPC and predictive control based on Lyapunov method is carried out using Matlab/Simulink and the results of both methods are presented and compared with each other. Finally, it can be seen that in the Lyapunov-based method, the tracking of the reference current is smoother and with less fluctuations, and the seven-level rectifier voltage also has a more regular and sinusoidal waveform.

Brucellosis is the most common zoonosis and is a health issue in Iran. Considering this disease is endemic in Qaen, this study intended to investigate the epidemiologic characteristics of brucellosis during 2015-2021. This cross-sectional study was conducted on 421 brucellosis patients, based on the information from Qaen Health Center from 2015 to 2021. To describe the data, frequency, mean, and standard deviation indices and to analyze the data, Chi-square and T-test statistical tests were utilized using SPSS software version 21. The incidence rate was calculated based on 100,000 at-risk populations per year. The average incidence rate of brucellosis from 2015 to 2021 was 135 per 100,000. The highest incidence rate was 156 per 100,000 people in 2021, and the lowest was 20.58 per 100,000 in 2017. The mean age of brucellosis patients was 36.78 ± 19.85  years. The most frequent clinical symptoms were musculoskeletal pain in 317 cases (75.3%) and fever in 160 cases (38%). The consumption history of unpasteurized dairy products such as milk and cheese was 33% and 27%, respectively. Farmers and ranchers, with 239 cases (56.7%), and the rural living population, with 282 cases (67%), were the most frequent cases of brucellosis. The incidence rate of brucellosis in Qaen has an upward trend and is higher than the provincial and national averages. According to the latest national guidelines, this county is classified as a highly polluted region.

Being bitten by animals is a great threat to people's health because it can cause the fatal disease of rabies. Rabies in Iran is still one of the health-economic problems. Therefore, the current study was conducted with the aim of investigating the prevalence situation of animal bite cases in Qaenat city over 5 years. In this descriptive-analytical study, the statistical population includes the cases of animal bites referred to the health centers of Qaenat city during the years 2016-1400.The collected data was analyzed with spss software version 23 and Chi-square statistical test was used to check the relationship between the variables. In order to determine statistical significance, P-Value>0.05 was determined. 1326 cases of animal bites were reported with an average prevalence of 2.27 per 1000 people, of which 77.34% were men. 59.28% lived in rural areas. The average age of the subjects was 44.74 ± 24.12 years and they were mostly in the age group of 50 years and older (38.3%). 77.8% of the cases were bitten by dogs. The upper limb (43.1%) was the most bitten limb and the most cases were observed in April with 9.4%. With the increase of animal bites in Qaenat city and the importance of the resulting complications in terms of health and economy, the authorities should plan and intervene to reduce the cases by increasing the level of awareness through training and fighting against stray dogs.

The effect of ground proximity on the some performance parameters of tandem rotors was measured using a multifunctional test rig in this study. Trust, produced power and induced power measurements of the rotors were performed in three different overlap values ​​to investigate the effects of ground proximity on these values ​​in hover flight. The results showed that the positive effect of ground proximity on the produced trust of tandem rotors is more than single rotors. In the ground effect, as the amount of overlap of the tandem rotors increased and the effect of the fountain flow recirculated from the ground increased, the amount of thrust increased . The results of power measurements showed that with decreasing the height of the rotors in the ground effect, the amount of induced power as well as the negative effect of aerodynamic interference due to their overlap decreased, These findings lead to a new approach to evaluating the performance of this type of helicopters.

In this paper, CFD aerodynamic simulation of turbulent compressible fluid flow around high lifting control surfaces of a wide body heavy commercial aircraft in different flight phases using Spalart-Allmaras single equation density based to extract of the lift, drag and mean pressure aerodynamic coefficients has been carried out. Modelling of the wing of Airbus A380 in the actual dimensions based on super critical airfoil SC(2)-0610 using 3D design software SolidWorks to generate 2D and 3D geometries has been done. The unstructured mesh in 2D and 3D according to the different configurations of 2D airfoil/3D wing control surfaces has been done using ANSYS Workbench meshing tools and then the CFD modelling for a turbulent compressible subsonic air flow regime in 2D and 3D using ANSYS Fluent is done. Mesh independence study, model validation and comparison of the results for the 3D wing is done. The effect of changes of different configuration of slat and flap lifting devices in the leading and trailing edges and for different angels of attack before stall of the wing according to different flight phases (take off, cruise and landing phases) on the aerodynamic coefficients in the 2D/3D turbulent flow regime have been investigated. Contours for pressure, velocity, Mach number distribution and velocity vectors around the A380 airfoil and wing control surfaces has been presented.

A review of the general strategies used in the aerodynamic optimization of the helicopter rotor has been done. The aim is reducing the computational resources of the optimizing process of the new aerodynamic designs of the rotor. This study begins with a brief review of the concepts and sources of the unsteady aerodynamics and the fundamental challenges to addressing this fundamental problem in helicopter rotor design and optimization. Then, past and present design and optimization methods used or proposed and the development of analysis tools to evaluate rotor performance reviewed to gain a better understanding of the problem. The results showed that despite the use of classical aerodynamics, wind tunnel, model rotor experiments and aerodynamic calculations in the past, the recent development of computational fluid dynamics (CFD) now provides an opportunity to accurately predict the viscous and compressible flow field and provide predicting the new rotor designs performances’. Therefore, the use of these tools for highfidelity simulations along with the use of surrogate modeling methods with variable fidelity will cover most aspects of the aerodynamic optimization problem of the helicopter rotor with reduced computational and time resources.

The purpose of this study was to develop strategic themes for the development of Iranian handball.The research is strategic in terms of subject matter; it is applied in terms of purpose and it is descriptive in terms of method and its data collection is survey. The statistical population was the experts Using both theoretical and snowball sampling methods 30 individuals were considered as sampleA combination of qualitative and quantitative methods was used to collect and analyze data. The research tool was a researcher-made checklist, which was confirmed by experts on its face and content validity, interviews and strategic council meetings were used to collect information. Logical inductive method was used to analyze the required information in the quantitative section of the matrix of position assessment and strategic action and matrix in the qualitative section. The Iranian Handball Federation has five macro-general sports exercises in the community, the development of championship sport, the promotion of professional sports, the promotion and consolidation of the organizational status of handball in all provinces, deepening and strengthening the morale of chivalry and orality through handball exercise, while the strategy approach The sport of the Iranian Handball Federation was based on an assessment of strategic position and strategic matrix in an aggressive position. Therefore, the brand promotion of the Iranian Handball Federation was chosen to maintain the status quo in the competitive market as one of the market leaders as a priority strategy.

Childbirth, as an ancient event in human life, has always created events and beliefs by man throughout history and has left with him a memory that has been highly diverse and attractive to women. Khale Roro play is an authoritative, purposeful review and reminder of the role and presence of women in the family, which, by repeating it in women's assemblies, pays a kind of appreciation for the role of women within this spectrum. In this article, by focusing on the customs related to childbirth, the rituals of childbirth among Iranian people are examined and studied and matched with the dramatic mirrors about this ritual in Hormozgan women's circles In order to reveal and identify the beliefs and beliefs related to birth, insight and worldview of Hormozgan women should also be analyzed. In this research, the sociological and psychological study of the performance of Khale Roro play - Ofina - along with the performance of the ritual in Hormozgan - Rudan - has been studied. Based on this research, how the women of Hormozgan use the theatrical element of religion as a tool to express their needs and the process of performing this play is analyzed. Since with the development of modernity, many dramatic mirrors of popular culture are declining and forgotten, the representation of these mirrors is necessary to understand the cultural past of women in different parts of Iran.

Coronavirus disease 2019 (COVID-19) is an emerging disease, whose first case was reported in December 2019, and rapidly affected the world. Therefore, the present study was conducted to investigate the frequency and factors associated with morbidity and mortality due to COVID -19 in Ghaen, Iran.

This retrospective descriptive-analytical study used the information sources of the portal of Shohada Ghaen Hospital, Gaen, Iran, from March 2020 to December 2021, which was collected from 1,124 patients with suspected respiratory infection referring to the hospital. Data using Chi-square and Fisher's exact test for univariate relationships. Moreover, two-way logistic regression was used to investigate the causal relationships, and P<0.05 was considered statistically significant.

In this study, the mean age of participants (n=1,124) was obtained at 51.6±24.5 years, and 546 (48.6%) subjects had a positive COVID-19 test by reverse transcription polymerase chain reaction, among whom 65 (11.9%) cases passed away. Clinical symptoms of body aches, coughs, diarrhea, and shortness of breath were associated with a positive COVID-19 test. It was also revealed that habitat, diabetes, cardiovascular and lung diseases, age, and job were risk factors of COVID-19 infection, and hospitalization in the ICU and age were identified as risk factors for COVID-19-caused death (P<0.05).

In the present study, cough and shortness of breath were found to be the most frequent symptoms among patients and deceased individuals. Since these symptoms may be associated with a worse prognosis, they require the special attention of medical staff. The findings of this study also showed that the elderly were more at risk of death from this disease than other age groups, which increased the need for more education and attention to this group of society.

In this study, a multipurpose testing equipment with a sub-scale model body with tandem rotors configuration was used to carry out a number of experiments in order to understand the inflow and down wash behavior of these rotors. The results showed that for single rotor, inflow is descending except in central areas. By using the data obtained from the experiments, an approximate pattern of inflow and downwash of rotor was presented. This pattern was found to be similar to the pattern that was presented for conventional helicopters rotors under settling with power condition. This phenomenon is one of the reasons contributing to the formation of an unstable turbulent flow in the central areas of the rotor. The results showed that interacting of the two tandem rotors has an effect on the behavior of the rear rotor inflow and changes its behavior in comparison with single rotor. It was observed that the results obtained from this study were more realistic due to considering the effects of the body, actual fluctuations of the flow. The experiments in this study showed differences exist in the principles governing the aerodynamic performance of rotors used in UAVs in comparison with conventional helicopters rotors. Therefore, it is necessary to pay enough attention to these differences and behaviors in predicting the aerodynamic performance and design of this type of flying machines.

Wind turbines are one of the most important renewable energy production devices and improving their efficiency leads to more effective exploitation of clean energies. Flow separation on wind turbine blade is one of the major reasons of performance loss in wind turbines. The present paper investigates the effect of single dielectric barrier discharge plasma actuator (SDBD) placement on a critical section of wind-electric wind turbine blade (660kW)) designed inside country. An experimental investigation for assuring the validity of the numerical simulations has been performed. Then, two dimensional simulations were extended to evaluate the effect of plasma actuator performance on flow characteristics. Numerical simulations are based on the latest enhanced electrostatic plasma actuator models. The fluid flow is incompressible and the free stream velocity is about 20m/s. The results clearly indicate that frequency and voltage increase can significantly correct the flow pattern in post stall condition. A linear pattern has been achieved between the frequency and aerodynamic coefficients variations. The best improvement for the range under investigation is more than 800% for aerodynamic performance and approximately 50% for separation point delay.

In the present study, the instantaneous velocity profile behind an airfoil at two different Reynolds numbers has been measured experimentally. Data are used to study the wake profile and the corresponding drag coefficient force of the airfoil in different conditions. In the conventional and common methods for calculation of the drag force coefficient through the velocity measurement behind an airfoil, turbulence velocity terms of the momentum equation are ignored. However at moderate to high angles of attack where the flow becomes turbulent and separation occurs, the nature of the flow becomes three dimensional and disregarding the components of the fluctuation of velocity (in three dimensions) in calculation of the drag coefficient of airfoil may result in erroneous information. In the present study, in order to increase the accuracy of the experimental drag coefficient of the airfoil for moderate to high angles of attack, turbulence velocity terms in experimental drag coefficient calculation are considered and this causes an acceptable compatibility between experimental and numerical results whereas for low angles of attack, disregarding the effects of turbulence velocity terms in experimental drag coefficient calculation will improve the accuracy of the experimental drag coefficient and a desired compatibility between experimental and numerical data will be established.

In this study, multipurpose testing equipment with a sub-scale model of a specific tandem rotor helicopter constructed to conduct a number of experiments to accurate understanding from the tandem rotor's outwash in ground effect. The experiments conducted as measuring rakes were positioned at two distances equal to 1.5 R and 3R from the rotor(s). Unlike the experiments that have been performed in wind tunnels or in special hover chambers, these experiments were performed in an open environment with fewer side walls effects. The results show that when the single rotor operates in a fixed altitude, and the blades tip velocity of 0.2M, the outwash velocities reduces as the flow moving away and vice versa, but for tandem rotors, increasing the rack distance from the model does not have a noticeable effect on the average values of the flow velocity. A comparison of the results of these measurements with the CH-47D helicopter outwash patterns confirms the accuracy of the obtained patterns and showed that the overlap between the rotors increases the velocity values and causes to the occurrence of maximum outwash velocity at lower altitudes. No overlap between the tandem rotors makes the outwash flow pattern of each of them similar to a single rotor. Increase in ground effect as the height of the rotor(s) decreases to 1R, changes the flow pattern in the forward and aft of the model helicopter. In this altitude, unlike their operation in altitude of 2R, the outwash flow increases when moving away from the rotor(s).

Effects of reduced frequency, pause duration and stop angle on pressure distribution on the lower surface of thin supercritical airfoil undergoing the pitch-pause-return maneuver have been studied. The experiments have been performed in a subsonic wind tunnel for a fixed mean angle of attack and at constant amplitude. The reduced frequencies were from 0.01 to 0.12, and three stop angles were chosen during upstroke motion in below stall, near stall and post stall regions. For all angles of attack below the static stall, the pressure distributions are nearly identical at the rear quarter chord on the lower surface. For beyond the stall angles, the lower surface pressure distributions are observed to remain unchanged from the leading edge downstream to x⁄c=0.15. Also dynamic results show that the behavior of pressure distribution at the lower surface taps for all reduced frequencies and pause durations, are identical from leading edge to x⁄c=0.70 and are higher than the static values at zero angle of attack. However, the lower surface pressure distributions have been observed to be entirely different at the rear 30% chord for various pause angles, which can be deemed to be the signature of the unsteady Gortler vortices.

A new approach using the genetic algorithms has been presented to estimate the uncertainties in numerical pressure calculation on a 3D wing. The amount of error in this method has been estimated in the form of power series as a function of the element size. The error tensor is expressed as the sum of squares and has been used as the fitness function in the genetic algorithm. The conventional method for error minimization has been differentiation which is replaced by the genetic algorithm in this paper. The error analysis along with a safety factor has been introduced as the uncertainties in numerical calculations. According to the results, refining the grids down to 25% of the initial size, reduced the error by an amount of 50%. The total uncertainty calculated in this paper was 0.03. This value determines a confidence level of 97.6%. The reliability of the results on three baselines higher than 97% approves the high accuracy of the present calculations. The highest and the lowest reliability in the present calculations was 99.16% and 97.6%, respectively.

In recent decades, the unprecedented lack of water resources, contamination and ecosystem degradation in many parts of the world have forced researchers and policy makers to devote more efforts to maintain and restore the health of water associated systems to achieve a balance between human and nature. Human efforts to maintain full natural flows have had implications on the functions and biodiversity of river systems. Lake Bakhtegan and Kor River have been degrading in recent years due to the lack of environmental protection efforts. The purpose of this paper is to provide a comprehensive top-down methodology for assessing the environmental flow of Kor River. Adopting the methodology based on the system dynamics approach, the paper will estimate the environmental flow requirement of the river under different scenarios and explores its consequences on the socio-economic part of the basin. It was observed that by supplying the water needed by the natural system, the resources available for economic development would decrease, impacting particularly the level of agricultural development. The current trends which are dominating the basin will result in deterioration of water resources and complete destruction of ecosystems.

Background and Sand flies are widespread in Iran and are vectors of leishmaniasis and pappatci fever in most parts of the country including Southern Khorasan Province. Faunistic and ecological studies of these flies are necessary in order to implement proper vector control programs. This research was conducted to determine the sand flies fauna in Southern Khorasan province. Sand fly specimens were collected from seven cities in Southern Khorasan province during May to August 2012 using sticky paper traps. The specimens were identified and their monthly activity and frequency in the province were measured. In this study, a total of 1294 insect specimens was collected of which 171 sand flies were identified. Species belonged to Phlebotomus and Sergentomyia genera including four species: Phlebotomus sergenti s.l., Ph. papatasi, Sergentomyia sintoni and S. dentata. Phlebotomus sergenti s.l. was the dominant species in this study which is also the main vector of cutaneous leishmaniasis in Iran. The most and the least abundances were observed in Darmian (29.2%) and Boshrooye cities (1%), respectively. According to the results, two vectors of cutaneous leishmaniasis were found to be active in studied area. Ph. sergenti s.l. was the dominant species in all study areas with relatively high frequency especially in July. Therefore, the health system of the province should be aware of the potential of anthroponotic cutaneous leishmaniasis (ACL) in these areas.

A s e r i e s o f s u b s o n i c w i n d t u n n e l e x p e r i m e n t s w e r e c a r r i e d o u t t o i n v e s t i g a t e e f f e c t s o f t h e p r e s e n c e a n d p o s i t i o n s o f a c a n a r d o n t h e v e l o c i t y f i e l d o v e r a d e l t a w i n g. I n t h i s r e s e a r c h, f l o w f i e l d m e a s u r e m e n t s o n a o n e-m e t e r a l u m i n u m a l l o y m o d e l a r e p e r f o r m e d. I n o r d e r t o u n d e r s t a n d c a n a r d i n f l u e n c e, t h e c a n a r d w a s s e t a t t w o v e r t i c a l p o s i t i o n s, h i g h a n d m i d, w i t h r e s p e c t t o t h e w i n g l e v e l. F l o w f i e l d m e a s u r e m e n t s w e r e p e r f o r m e d t o s t u d y t h e m e c h a n i s m o f c a n a r d-w i n g v o r t e x i n t e r a c t i o n s. T h e d a t a s h o w t h a t c a n a r d v e r t i c a l p o s i t i o n s h a v e a s i g n i f i c a n t i n f l u e n c e o n t h e v o r t i c e s l o c a t i o n s, a s w e l l a s o n v o r t e x b r e a k d o w n. R e s u l t s o f t h e f l o w f i e l d m e a s u r e d b y a s p e c i f i c r a k e s h o w t h a t t h e w i n g l e a d i n g e d g e v o r t e x b e c o m e s s t r o n g e r b y i n c r e a s i n g T h e a n g l e o f a t t a c k. I n a d d i t i o n, t h e v e r t i c a l d i s t a n c e o f t h e v o r t e x, w i t h r e s p e c t t o t h e w i n g s u r f a c e, i n c r e a s e s, a n d t h e p o s i t i o n o f t h e v o r t e x b r e a k d o w n m o v e s u p s t r e a m. T h e p r e s s u r e l o s s i n d u c e d b y t h e c a n a r d v o r t e x o n t h e w i n g s u r f a c e m o v e s t h e w i n g v o r t e x t o w a r d t h e l e a d i n g e d g e. W h e n t h e t w o v o r t i c e s a r e p l a c e d a t a n a p p r o p r i a t e d i s t a n c e f r o m e a c h o t h e r, t h e i r m e r g i n g c a n l e a d t o a s u d d e n p r e s s u r e l o s s. I n t h e m i d c a n a r d c o n f i g u r a t i o n c a s e, b o t h c a n a r d a n d w i n g v o r t i c e s m e r g e a t x/c $s u c c$ 0.5, a n d, a s a r e s u l t o f t h i s p h e n o m e n o n, a b r u p t p r e s s u r e l o s s o c c u r s a n d a s t a b l e v o r t i c a l f l o w i s m a i n t a i n e d o n t h e w i n g. I t i s s h o w n t h a t l o w a l p h a c a n a r d d e f l e c t i o n s, w i t h r e s p e c t t o t h e w i n g o r f r e e s t r e a m, m a k e s s i g n i f i c a n t c h a n g e s t o t h e f l o w f i e l d o v e r t h e w i n g.

Aspects of pitching and plunging motions on unsteady aerodynamic behavior of an aircraft model were studied. Extensive wind tunnel tests were performed on a standard dynamics model, SDM, oscillating in both pitch and plunge modes. Up to now, there has been little or no result on the plunging behavior of an aircraft or missile as a whole and the present experiments can be considered as one of the first attempts to study the compressible flow field over a model undergoing both pitching and plunging motions. The experiments involved measuring normal force and pitching moment of the model at Mach numbers of 0.4, 0.6 and 1.5 and oscillation frequencies of 1.25, 2.77 and 6.00 Hz. The longitudinal dynamic derivatives were then calculated from the measured data. The pitching results have been compared with the available data on the same model and good agreement has been achieved. However no plunging data on the same or a similar model was available in the literature to be compared with the present findings.