9 research outputs found

    Experimental Study of Flow over and Under Half-Cylindrical Gate with Rotation 180 Degree around Central Axis

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    Introduction: Because of the fairly simple equations for accurate flow measurement and controlling the water level, weir and gate method is more useful than the separate weir, gate and partial flume methods. Since the flowing water in the channel always contains sediment particles and floating debris, they are deposited at the gate inlets and behind the weirs which reduces the size of the channel in the structure range and which reduces some problems such as neighboring land flooding due to overflow of water from the channel banks, threatening the structure stability and reducing the measurement accuracy. Using a combination of weir- gate model, in comparison with other conventional devices, will make it possible to get the actual conditions closer two main hypotheses derived from the relations and accurately measure the discharge coefficient. In this model, the deposited materials are easily passed through the gates and the suspended debris are easily passed over the weirs. One of the combined weir- gate structures is semi cylindrical weir- gate structure. Regarding about the form of the combined weir- gate structures, it has some advantages , including simple design, sediments and floating material flow, high flow discharge coefficient compared with other replaceable structures and its being economic. Semi Cylindrical gate turning around center Axis, for reason of rotation the center becomes Conversion to wire, wire gate with opening with different height. Materials and Methods: The experiments were conducted in a rectangular flume with the length of 8 m, width of 0.282 m and height of 0.3 m in Soil Conservation and Watershed Management Research Institute. In this research, PVC pipes were used as semi cylindrical gate structures. The experiments were conducted for three diameters 70, 120 and 160 mm with height of the opening between zeros until radius, angles zero, 30, 45, 60 and 90 degree and differently discharging. Experiments were performed at a discharge limit of 2-27 l/s. In order to decrease turbulence of the flow, the gate was installed at the end 4 m of the flume. The ratio of cylindrical structure diameter to channel width (D/B) was in the range of 0.25 to 0.57 and the Froude number was in the range of 0.08 to 0.55. Results and Discussion: Coefficient discharge of semi cylindrical structure and then dimensionless parameters of [H/P], [a/H], [ /H] and [Fr] against the discharge coefficient in the studied gate opening between zero until radius were investigated. According to result with decrease dimensionless parameter of a/H, discharge coefficient increased, So that the maximum Coefficient discharge rate of angle 90 degrees and minimum angle 0 degrees. Also in a constant of a/H for the curvature of the downstream and upstream, with increasing the diameter of semi cylinder, discharge coefficient remains and has no change, shows that changes in diameter of semi cylinder have no significant impact on discharge coefficient. With increasing H/P for both curves upstream and the downstream, discharge coefficient increased. Also in a constant of H/P for the curvature of the downstream and upstream, with increasing the diameter of semi cylinder, discharge coefficient remains. With constant of angles with increasing Freud for all angles, both the curvature of the downstream and upstream, /H decreased. Also in a constant of Freud and angles, with increasing the diameter of semi cylinder, /H remains. According to the result, discharge coefficient of semi cylindrical gates varies, in Experimental limit, from 0.45 to 1.45 which is more than that of sluice gates reported by the USBR. One of the reasons, this is ascribed to this is the difference between the amount of entrance, head loss in this structure, because when the flow approaches cylindrical gate, due to curvedness of the wall upstream, a gradual gathering of flow lines gives the aerodynamic method to entrance section, thus decreasing resistance against the flow and entrance head loss and increasing discharge coefficient. However, in sluice gates the vertical wall in entrance section is conducive to fast gathering of flow line, thereby increasing resistance against flow, increasing entrance head loss, and decreasing discharge coefficient relative to a semi cylindrical method. Conclusion: The results showed that increasing Froude coefficient and decreasing the a/H (ratio of gate opening to upstream water depth) dimensionless parameter decrease, respectively increase the discharge coefficient and decrease head loss in all aspects of structural alignment. Within addition by increasing the H/P dimensionless parameter (ratio of upstream water depth to structure diameter) discharge coefficient increased. Results showed that the maximum and minimum values of discharge coefficient are related respectively to 90 degree and 0 degree angle

    Comparing systolic and diastolic Blood pressure changes and heartbeat rate following administration of anesthetics containing epinephrine and felypressin

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      Complex mechanisms have been known for keeping blood pressure in normal level. In fact, these mechanisms have inter-related functions and can be dysregulated by both internal and external stimuli while cardiovascular system functions to minimize these changes. Vasoconstrictors can cause clinical and hemodynamical changes as 1-2 cartridges of epinephrine containing lidocaine can has no considerable effects in a normal individual ( unless administered IV) but 3 cartridges can bring about some clinical symptoms, according to a number of investigations. In current study, epinephrine’s effect on heartbeat rate was found more potent than felypressin which is considered as a disadvantage. on the other hand, epinephrine acts on arteries and can cause less bleeding, less drug toxicity and deeper and longer anesthesia. Therefore, it is preferred to felypressin due to its better action. It should be noted that the changes resulted by epinephrine and felypressin are of no significant importance in healthy individuals

    MicroRNA-196a as a Potential Diagnostic Biomarker for Esophageal Squamous Cell Carcinoma

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    We observed significant up-regulation of miR-196a in esophageal squamous cell carcinoma (ESCC) as compared with their adjacent normal tissue (p =.002). Receiver operating characteristics curve analysis confirmed the suitability of miR-196a as a potential tumor marker for diagnosis of ESCC. Furthermore, analysis of miR-196a levels in saliva samples determined an average of 27-fold up-regulations in ESCC patients compared with healthy group. Our results suggest that salivary miR-196a may be a suitable noninvasive biomarker for diagnosis of ESCC. In addition, molecular pathway enrichment analysis of microRNA (miR)-196a determined focal adhesion, spliceosome and p53 signaling pathways as the most relevant pathways with miR-196a targetome. © 2017 Taylor & Francis Group, LLC
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