فهرست مطالب m.seifi

In recent years, the limitations of the non-renewable energy sources and the rising pollution of their overuse have led the attention to renewable and clean energy sources such as the potential energy in water resources. Because of vastly used water transportation pipelines and the existing extra pressure in these pipes, it has a high potential for generating electrical power using the in-pipe turbines. In this research, the designing, simulation, and power optimization of a particular kind of these turbines (lift type) are studied. The numerical simulation is performed by Ansys Fluent commercial package software using a 3D solver for unsteady and incompressible flow in conjunction with a proper turbulence model. After introducing the turbine's effective design parameters, the simulation of the in-pipe turbine with different geometry conditions and rotational speeds is performed and discussed. Then it is tried to enhance the generated power of the turbine using trial and error by changing the geometry conditions of the rotor. Lastly, by numerical simulation of different geometries and improving the generated power, the best turbine geometry is tested for experimental validation.

Different medicines are utilized in giving nerve block. The different drugs are usually discussed concerning efficacy and persistence of pain relief. The present study aimed to compare the use of lidocaine alone with granisetron/lidocaine combination in terms of the efficacy and persistence of the analgesic effect, in the axillary block used in patients requiring elbow or below elbow surgery.

A double-blind randomized clinical trial was performed on 90 patients who were candidates for elbow surgery. In this regard, an ultrasonography-guided axillary block was performed by a linear transducer using a short-axis in-plane technique. The first group was given lidocaine, whereas the second group received granisetron/lidocaine combination. First, five mg/kg of lidocaine %0.5 was diluted to 40 ccs with 0.9% saline. In the first group, 40ml of lidocaine solution was injected after dipping the syringe in epinephrine. In the second group, 2 mg of granisetron was injected simultaneous with lidocaine solution.

In total, 90 patients entered the study and were divided into two equal groups of 45. The mean age of the patients was 34.48±9.0 years (18-58 years). 61 (67.8%) participants were male and 29 (32.2%) female. The onset time of sensory and motor block in the second group (granisetron/lidocaine combination) was significantly lower, compared to the lidocaine -alone group . Moreover, the continuity of sensory and motor block was significantly higher in the second group. Furthermore, the first analgesic requirement time was significantly lower in the granisetron/lidocaine combination group, compared to the lidocaine- alone group (P<0.001).

The concomitant use of granisetron with lidocaine improved all pain indicators and  also led to faster and more continuous sensory and motor blocks .

The present study aims to analyze the content of second grade chemistry textbooks based on the emphasis on the goals of resistance economy.

The research method in this study was descriptive content analysis. In this study, after collecting quantitative data, Shannon entropy technique was used for anarysis. The statistical population of this study formed the content of all secondary high school chemistry textbooks. The sampling method in this study was census; Therefore, all second grade chemistry textbooks were analyzed. The registration unit in this study was the subject. In this study, the frequency of components and themes of resistance economy in chemistry curricula were examined.

The findings of the content analysis showed that in secondary high school chemistry books, the most attention was paid to the goals of resistance economy in the field of consumption the field of skills and the field of production attitude.

From the present study, it can be concluded that in the second grade chemistry textbooks, very little attention has been paid to the goals of the resistance economy. Also, in secondary school chemistry curricula, little attention has been paid to the goals and components of the resistance economy and the amount of attention to the goals of the resistance economy do not have a normal distribution and only some components of the resistance economy in the second secondary school (three dimensions and three areas) are consi dered.