Roll motion is one of the most important and dangerous motions of the ship and can even result in capsizing of the vessel. Therefore, its control has been always of interest for marine industry researchers. Among the various methods and equipment for controlling the roll motion, the use of free surface anti-roll tanks has been one of the most important methods and which used in many cases due to its simplicity in construction and design. The high efficiency of these tanks at all speeds and even without speed is another strength of these tanks. This study investigates the effect of the free surface anti-roll tank on the roll motion numerically and experimentally. In the numerical simulation, a CFD sloshing solver, based on the “ Open source Field Operation And Manipulation” , known in short as Open-FOAM, and assuming 2D laminar flow conditions, is customized to calculate the sloshing loads from the tank. The predicted roll damping and moments due to the anti-roll tank are validated against experimental results. This simulator could be used as a sloshing simulator to couple with seakeeping solvers.

Background and Aims: More than 60 % of runners suffer from overuse injuries each year. Exercise and Running surfaces can prevent injuries and/or improve performance. The present study aims to investigate the effect of three types of running surfaces (Polyvinyl Chloride (PVC), artificial turf, and sand) on the Ground Reaction Force (GRF) components in the stance phase of running. Methods: Impact force, loading rate, and free moment of 15 men were recorded while running barefoot on three PVC, artificial turf, and sand surfaces at a speed of 3± 0. 2 m/s (Average of 5 correct attempts). Comparison between different conditions was performed using repeated measures ANOVA and Bonferroni’ s Post-Hoc Test. Results: The sand surface significantly reduced the impact force compared to the PVC and artificial turf. Both sand and artificial turf caused a significant reduction in the force loading rate compared to the PVC surface. The second peak of vertical GRF (propulsive force) increased at sand (P=0. 001) and artificial turf (P=0. 005) surfaces compared to the PVC surface. Moreover, the sand surface reduced adductor torque compared to the PVC (p < 0. 001) and artificial turf (P=0. 003) surfaces, while the artificial turf reduced abductor torque compared to the PVC surface (P=0. 011). Conclusion: Sand is a safer surface for preventing running injuries due to eliminating impact force, reducing loading rate, and having high shock absorption. Training on a sand surface may improve performance on harder surfaces.

The major goal of the present research is to investigate about the effect of free cash flow on investment efficiency. The statistical population for the present study involves all firms enlisted in Tehran Stock Exchange. The sample included 134 firms regarding the definitions for the criteria utilized by the researcher and making benefit of a systematic deletion method. The research method is quasi-experimental using a post incidental approach. The research method is regression correlation-analysis of applied type and to investigate about the effect of the independent variable (free cash flow) on the dependent variable (investment) we have utilized economic measurement models. The hypotheses were studied by using a panel multiple regression method and the method used to estimate the data was a dynamic model using a generalized moment regression (GMM). Results showed that free cash flows have had a positive and meaningful effect on over-investment and under-investment.

Background and Aims Adolescent idiopathic scoliosis (AIS) is a multifactorial spinal deformity with high prevalence, affecting spinal alignment, postural control, and gait mechanics. This study aims to examine the effect of scoliosis curvature direction on center of pressure (COP) kinematics and free moment (FM) parameters during gait.Methods In this study, participants included 14 adolescents with AIS categorized into right scoliosis (n=7) and left scoliosis (n=7), and 16 healthy peers as controls. Data related to the COP and FM parameters were collected using two Kistler force plates during the stance phase of gait. Statistical analysis was done using MANOVA for discrete variables and statistical parametric mapping (SPM) for time-series data.Results The AIS group had significantly higher body height (P=0.021) and trunk length (P=0.052) than the control group. No significant differences were found in the COP and FM parameters for the right leg between the groups. However, the left scoliosis subgroup showed a significantly larger range of anteroposterior COP displacement in the left leg (convex side) compared to the control group (P=0.027), as well as a larger FM mean and impulse compared to the right scoliosis subgroup (P=0.019).Conclusion Adolescents with right and left scoliosis demonstrate different gait adaptations, particularly in COP and FM dynamics, highlighting the need for curvature direction-specific rehabilitation protocols to enhance gait stability and neuromuscular control in AIS. Future studies should analyze scoliosis directions separately to characterize their biomechanical profiles.

Background and Aims: There are three types of footstrike patterns that runners use including rearfoot strike, mid-or forefoot strike. The aim of the present study was to investigate the effects of running with different patterns on loading rate, impulse, and free moment values in three dimensions during stance phase. Materials and Methods: A total of 13 healthy men (age: 26. 6± 2. 8 years; weight: 78. 4± 7. 2 kg) were included in the present trial and semi-experimental study. Ground reaction force data was recorded using a Kistler force platform (sampling rate: 1000 Hz). Two-way ANOVA with a significance level of ɑ =0. 05 was used for statistical analysis. Results: The results of the current study showed that the vertical ground reaction force during the mid-stance phase of the rearfoot strike without shoe was more than that of the rearfoot strike with shoe. External force in the heel contact phase showed a significant decrease while running forefoot strike versus running with a rearfoot strike pattern. The vertical loading rate was higher when running with shoes compared to without shoe in the rearfoot strike pattern. Conclusion: According to the results, it can be concluded that the rearfoot strike pattern has reduced the amount of external component and thus the amount of foot pronation relative to the forefoot strike pattern, which can reduce the risk of injury.

Progressive collapse studies generally assess the performance of the structure under gravity and blast loads, while earthquakes may also lead to the progressive collapse of a damaged structure. In this study, the progressive collapse response of concentrically braced dual systems with steel moment-resisting frames was assessed under seismic loads through pushover analysis using triangular and uniform lateral load patterns. Two different bracing types (X and inverted V braces) were considered, and their performances were compared under different lateral load patterns using the nonlinear static alternate path method recommended in the Unified Facilities Criteria (UFC) guideline. Eventually, the seismic progressive collapse resistance of models was compared to their progressive collapse response under gravity loads. These studies showed that models under the seismic progressive collapse loads satisfied UFC acceptance criteria and limited rehabilitation objective. The structures had better performance under seismic progressive collapse than models under gravity loads because of more resistance, ductility, suitable load redistribution, and more structural elements that participated in load redistribution. Furthermore, despite studies on progressive collapse under gravity loads, the dual system with X braces showed better progressive collapse performance (more resistance, residual reserve strength ratio and ductility) under seismic loads than the model with inverted V braces.

Aim: The aim of this study was to evaluate the prevalence of dental caries in 6 - years - old children of Khomein town.Method & Material: The present study was descriptive and crosses- sectional. A total of 7I3 student of this age, 485 in the city (245 boys, 240 girls) along with 227 students in the rural regions (119 boys and 108 girls) were selected for the study.Results: The results showed the prevalence of caries free about 18.7% in primary dentition and 19.2% in permanent dentition and the total percent of 18%.The prevalence of caries free was higher in boys than girls. The mean of dmft and DMFT in total was 4.02 and 0.15. The most dental treatment need was Cl 11 restorations (31.25%). Caries free prevalence in the city (19.2%) was more than rural areas (15.2%).Conclusion: The results of this study showed high difference between WHO standards and what found in the studied area, showing great needs for providing dental services and health instructions.