This paper is devoted to explore the relationship between earthquake INTENSITY in the epicenter and its magnitude as well as the INTENSITY ATTENUATION LAWS of the Iranian earthquakes. For this purpose, available data, reports, seismotectonic and isoseismalmaps, related to 21 destructive earthquakes in a period of 1957 to 1998, were studied.The results show that the INTENSITY-magnitude relationships and the INTENSITY ATTENUATION LAWS are strongly dependent on the site geology that specifies local effects. Therefore, the sites have been classified, according to site geology, into two groups, hard sites and soft sites. The INTENSITY-magnitude and INTENSITY ATTENUATION versus the distance from the earthquake sources (surface refaulting of the causative fault (s)) were determined and introduced for each of the two site groups. Finally, the obtained LAWS were compared with some other LAWS offered by other researchers.

The isoseismal maps for 22 earthquakes in different regions of Iran were analyzed to study the ATTENUATION of seismic INTENSITY with the distance from the epicentre under a certain surface wave magnitude (Ms). The ATTENUATION relationships were derived by using an iterative least squares fit procedure. These equations were derived from more basic concepts assuming that the INTENSITY is proportional to the logarithm of seismic energy density at any location empirically. The isoseismal maps are elongated in the direction of local structural trend of causative faults. Therefore, ATTENUATION relationships for the main direction of fault, transverse to it and average ATTENUATION were derived. Ia = 11. 564 + 0. 943 M − 2. 508 Ln(Ra + 33) ,  ,  ,  ,  ,σ = 0. 79 ,  ,  ,  ,  ,  ,Ra <, 200 km along the main direction of fault Ib = 9. 469 + 0. 717 M − 2. 121 Ln(Rb +13) ,  ,  ,  ,  ,  ,σ = 0. 49 ,  ,  ,  ,  ,Rb<, 140 km transverse to the main direction of fault I =11. 926 + 0. 831 M − 2. 7 Ln(R + 22)  ,  ,  ,  ,  ,  ,  ,  ,σ = 0. 49 ,  ,  ,  ,  ,  ,  ,  ,R<, 167 km average ATTENUATION Where M is the surface wave magnitude and I is the INTENSITY at a distance R (km) from the epicenter. The ATTENUATION of seismic INTENSITY in Iran is faster than the East and West of China and Sicily and Calabria in Italy, apart from different tectonic characteristics of these regions.

The earthquake is one of the natural hazards that have caused many casualties and financial losses throughout the world over the years. This has been the reason why the earthquake hazard analysis studies should be studied more seriously. Iran is also located in one of the seismically active regions of the world, the Himalayan-Alpine belt, which experiences many earthquakes every year. The Arias INTENSITY function, as one of the important earthquake strong motion parameters, contributes greatly to the analysis of seismic hazard, which can be used to estimate the stability of slopes during the earthquake. The purpose of this research is to develop a new ATTENUATION relationship for Arias INTENSITY function in the Iranian plateau using intelligent methods. In this research, 1012 strong motion data were used. Initially, the data required to be filtered were corrected and then all data was analyzed. In this study, parameters such as magnitude of earthquake, focal depth, shear wave velocity and geographic position of the region were used as a variable for the ATTENUATION relationship. Moment magnitude (Mw) was used as earthquake magnitude and earthquakes with magnitudes of above 4 were used in this research. The geographic location of Iran was divided into two regions of Central Alborz and the Zagros region. Gene Expression Programming (GEP), a kind of intelligent algorithm, was used as a method for regression and calculation of the objective function. The advantage of this method is that at first the model for the objective function is not specified and the model is presented optimally by the intelligent method. The fitness function is also defined based on the root least squared error (RMSE). Finally, the ATTENUATION relation based on this fitness function was calculated and the observed results have a high fitness.

SPECT detects γ-rays from administered radiopharmaceutical within the patient body. γ -rays pass through different tissues before reaching detectors and are attenuated. ATTENUATION can cause artifacts; therefore different methods are used to minimize ATTENUATION effects. In our study efficacy of Chang method was evaluated for ATTENUATION purpose, using a custom made heart phantom. Due to different tissues surrounding heart, ATTENUATION is not uniform more over activity distribution around heart is also non-uniform. In Chang method, distribution of radioactivity and ATTENUATION due to the surrounding tissue is considered uniform. Our phantom is a piece of plastic producing similar SPECT image as left ventricle. A dual head, ADAC system was used in our study. Images were taken by 180° (Limited angle) and 360° (Total rotation). Images are compared with and without ATTENUATION correction. Our results indicate that Chang ATTENUATION correction method is not capable of eliminating ATTENUATION artifact completely in particular ATTENUATION effects caused by breast.

Metabolic syndrome (MetS) elevates thrombotic risk through dysregulated coagulation factors, including plasminogen activator inhibitor-1 (PAI-1) and fibrinogen, driven by visceral adiposity and metabolic dysfunction. High-INTENSITY interval training (HIIT) improves cardiometabolic health, but its effects on hemostatic markers in MetS remain underexplored. Twenty-four men with MetS (ATP-III criteria; age 44.4 ± 5.4 years, BMI 31.7 ± 2.3 kg·m⁻²) were randomized to HIIT (n=12) or control (n=12). HIIT comprised 3 sessions/week for 8 weeks (4 × 4-min intervals at 90% HRmax, interspersed with 3-min active recovery at 70% HRmax). Fasting plasma PAI-1, fibrinogen, insulin resistance (HOMA-IR), body composition, and lipid profiles were assessed pre/post-intervention. HIIT significantly reduced PAI-1 (−30.7%, p<0.001) and fibrinogen (−21.8%, p<0.001) versus controls. Concurrent improvements occurred in HOMA-IR (−20.6%, p<0.001), body fat (−3.8%, p<0.05), systolic/diastolic BP (−7.5%/−5.2%, p<0.05), LDL-c (−5.6%), triglycerides (−9.4%), and HDL-c (+3.0%; all p<0.05). Control group exhibited no significant changes. HIIT attenuates prothrombotic risk in MetS, evidenced by reductions in PAI-1 and fibrinogen. These hemostatic improvements are mechanistically linked to ameliorated metabolic dysfunction, highlighting HIIT’s role in modulating adipose tissue–vascular cross talk.

One of the INTENSITY modulated radiation therapy (IMRT) methods is based on using compensators. The most important factor in designing a compensator is the accurate calculation of its thickness to achieve the INTENSITY modulation of interest. To achieve that, the exact ATTENUATION coefficient of compensator materials must be calculated. Using Map CHECK 2 model 1177 and phantom (SP34). We studied the effect of compensator thickness and field size on the calculation of the effective ATTENUATION coefficient (EAC) of the brass compensator for 6-MV photon beams. Experimental measurements were carried out at 100 cm source-to-surface distance and 5 cm depth for the 6-MV photon beams of an Elekta linac using various field size and compensator thickness. The field sizes investigated ranged from 1×1 cm2 to 20×20 cm2 and the brass compensator thickness from 0.5-6 cm. Our results indicated that the compensator thickness and field size have the most significant effect on the calculation of the compensator EAC for the 6-MV photon beam and also these parameters can reduce the error due to delivered dose to target volume and organs at risk.

Studying the nature of natural LAWS is a central and basic investigation in philosophy of science which penetrates well into the boundaries of epistemology and metaphysics.One of the most but interesting subjects in this regard is the "uninstantiated LAWS". In this paper, after explaining two main viewpoints on the nature of natural lawa, the way they treat the problem of uninstantiated LAWS is reported and their shortcomings are laid bare.

Introduction Monitoring and prediction of hydrologic droughts and determining the onset and duration of drought spells have an important role in water resources management and planning to reduce the adverse effects of drought. In the present study the characteristics of hydrological drought in daily discharge time series from 20 hydrometric stations in Golestan Province have been analyzed. Matherials & Methods: In this study, the onset and end of drought periods, mean discharge, effective discharge and threshold level were calculated and then sequence number of 1 to 30-month durations were determined. According to the results of Power LAWS Analysis, the INTENSITY and duration patterns of hydrological drought periods were distinguished. The results specified an inverse relationship between the INTENSITY and duration of wet and dry spells. The highest severity of dry spell is related to Nodeh station (Line slope=-0. 26) and the highest INTENSITY of wet spell was observed in Ramian station (Line slope =-0. 28) which indicated the stability of dry and wet river flow regimes in Nodeh and Ramian stations. Also, the longest durations of dry and wet periods were determined for the Aghghala (32. 89) and Basirabad (16. 29) stations, respectively, which represents the average maximum probable durations. Discussion of Results & Conclusions: The proximity, closeness to a straight line or parallel lines without intersection proved the homogeneity regime of wet-dry spells in the Gorganroud watershed. Analysis of wet-dry spells using the Power LAWS technique provides a basis to determine the flow regime, severity and duration of hydrological drought.

Helicopters can be a source of loud noise. The high production noise of helicopters makes them unsuitable for densely populated areas, especially in low-flying conditions. This study examines methods and offers solutions to reduce or eliminate the noise produced by helicopters. Several methods have been considered to reduce the noise produced. Solutions such as muffler for motors, use of modulated blade spacing, X-force control, reduced tip speed, blade tip modification, airfoil tailoring, Increasing the number of main rotor blades, active blade control and variable diameter rotor in The rotor and the use of the strut in the gearbox were introduced. According to the studies conducted in the present study, combined methods haveas the best noise reduction. although Independent methods reduce noise, depending on the amount of reduction required in the targeting, combining the methods can be achieved the appropriate answer.