فهرست مطالب shiva emami

The results show that the lidar in cold orbital conditions has a temperature increase of about 38 degrees Celsius due to thermal design. Also, the range of temperature fluctuations before applying thermal design in the cold state of temperature changes in a circuit is about 14 degrees and after designing these fluctuations have been reduced to about 5 degrees. In hot conditions, the temperature conditions have improved a lot after the design and the maximum operating temperature is about 27 degrees the average temperature has decreased by about 22 degrees, while the temperature fluctuations have also decreased by 21 degrees. A significant temperature increase has occurred in the receiver after applying the thermal design in cold conditions, which is still within the allowed range. This is despite the fact that in hot conditions, after applying the thermal design, there was no significant change in the temperature of the receiver. In the case of the reflector, the conditions are completely different, so the minimum temperature in cold conditions has increased by 42 degrees and the maximum temperature has decreased by 7 degrees in hot conditions. In addition, temperature changes have become more uniform in both cases.

This paper reviews design of Constellation for independent satellite-based navigation system with Middle East region coverage for regional positioning and augmentation service. Space segment of this constellation is composed of nine satellites in four orbits in such way three satellites have been placed on one GEO and two satellites on each three IGSO. In the coverage area, ground segment includes eleven ground monitoring stations, two masters and tracking control stations and twenty wide area reference stations are assigned only for augmentation with their master and uplink stations. Here we centered on space segment and specially design a navigation constellation system as a main orientation in this investigation and evaluation of the performance of the navigation system by combination with other satellite-based navigation systems. Hence, the parameters corresponding to navigation accuracy have been analyzed and compared with other active GNSS constellations. Analyses results express that geometric accuracy (GACC) of the designed system is solely 16 meters in 95% of a day in all points of desired area and in the case of combination with BeiDou and GPS the GACC would be improved to 14 and 12.5 meters respectively.

The CANSAT design, a simple and small scale of a satellite, is an experience for preparing for the design of a Life cycle of the space project. In this paper, the process of design and construction of ARTA CanSat, which is participated in the scientific-exploratory class of international competition in CANSAT Iran, has been written. The operation scenario is that an automatic scanner system, lands after releasing from 300 meters above ground level with using a recovery subsystem (parachute), which is controlled its downfall and landing position by the parachute controller system. During the descent, the data is transmitted by the sensors and sent to the ground station. After touchdown, the Hotwire system's operates and separates the parachute from the Rover section; Then CanSat with the moving on the ground by using the simpler section embedded underneath the structure, performing excavation while moving to the target point. Throughout the mission, the health of the biological payload is preserved.

Patellofemoral pain syndrome (PFPS) is a common disorder of the knee.­ the conservative treatment of patellofemoral pain syndrome is to correct shortness of soft tissue. The aim of this study was to determine the effect of PNF stretching exercise on PFPS.
Twenty female volunteers with PFPS were randomly assigned to PNF and control groups. The experimental group accomplished their own specific treatment protocols for 8 weeks, whereas the control group did not follow the treatment plan. Pain and functional disability were assessed by visual analogue scale (VAS) and Kujala questionnaire respectively, before and after exercise. Using SPSS 20 software, data were analyzed by t-test. P The experimental group showed a significant reduction in the pain (P We concluded that PNF stretching may have positive effects on PFPS.

Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa. The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran. Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates. Biofilm formation was observed in 70% of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9% (n = 15). The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation.

Acinetobacter baumannii has become a major cause of hospital-acquired infections due to its resistance to common antibacterial agents. Biofilm formation is a well-known pathogenic mechanism involved in A. baumannii infections.. The aim of this study was to determine the association between biofilm formation and antibiotic resistance, production of AmpC and Extended-Spectrum β-lactamases (ESBL) in clinical isolates of A. baumannii collected from two hospitals of Tehran.. Sixty isolates of A. baumannii were employed of which, 30 were burn and 30 were non-burn isolates. Biofilm formation was measured by the microtiter plate assay. The production of AmpC was detected by the AmpC disc test with cloxacillin, and ESBL production was determined using the double disc synergy test.. Biofilm production occurred in 61.7% of the isolates among which, non-burn isolates (59.5%) produced more biofilm compared to the burn strains (40.5%). Multidrug resistance was observed in both biofilm positive and negative strains. However, the non-burn isolates were significantly more resistant to meropenem and tobramycin regardless of their potential to form biofilm. Interestingly, biofilm-producing non-burn isolates were significantly more resistant to amikacin, gentamicin, tobramycin and meropenem. Production of AmpC was also significantly higher in biofilm-producing non-burn isolates. Conversely, ESBL production was significantly higher in burn isolates. There was an association between biofilm formation and AmpC but not ESBL-production among non-burn isolates.. The potential to form biofilm correlated with antibiotic resistance and AmpC production in non-burn burn isolates of A. baumannii. On the other hand, the burn strains produced significantly higher amounts of ESBL yet biofilm production was unrelated to antibiotic resistance or ESBL-production..