The effect of vortex flow in off-design conditions on the performance of the draft tube in a Horizontal Francis turbine has been investigated numerically.DTo validate the numerical approach, having experimental data in the draft tube is the immediate objective of this research. Thus, a three-hole pressure probe has been designed and mounted inside the draft tube for measuring the axial and tangential components of the velocity field. The specific speed of the turbine in the test rig was such that the radial component of the velocity at the inlet of the draft tube could be neglected, which justifies implementation of the applied probe, especially at the inlet of the draft tube.The velocity field is measured by traversing the probe at two sections of the inside of the draft tube. The velocity field data at the inlet of the draft tube are used as the boundary conditions of the 3D numerical analysis.It is well known that a high intensity vortex causes con-sider able degrees of anisotropy in stress and dissipation tensors, leading to a highly anisotropic eddy viscosity. Thus, all conventional eddy-viscosity-based models will no longer be valid under these conditions and Reynolds stresses in Navier-Stokes equations are modeled by using the RSM formulation.In this study, an emphasis is also placed on the influence of the inlet condition. Numerical results are in fairly good agreement with experimental data. Grid independency is carefully checked in the numerical approach.Several operating points, with different flow rates, under the constant head and rotational speed of the turbine, are investigated. For each case, by applying a numerical simulation at a constant mass flow rate, the pressure recovery factors are calculated in two ways, with and without the circumferential velocity component at the inlet of the draft tube. These are necessary tools to find the influence of the vortex on the draft tube efficiency.It is found that the vortex flow has an adverse effect on the performance of the draft tube and may, consequently, decrease turbine production.

In this study, nano-silica oxide's effect as a Drag Reducing Agent (DRA) of water flow in a 12. 7 and 25. 4 mm galvanized pipe was investigated. The studied parameters include Nano silica oxide concentration, Flow rate, temperature, and tube pipe diameter. To develop the conditions in preparing the Nano-particle on Drag Reduction (DR), nano-particles were provided in the top water-based fluid. To have a comprehensive analysis of process folding conditions, the experiments were carried out with three different drag-reducing concentration agents with three various temperatures and three different flow rates. Moreover, as a new method in this study, the experimental (Drag reduction percent) outputs were evaluated and analyzed using the Artificial neural network which is optimized by a genetic algorithm. In the consequence of algorithm genetic, the highest rate of drag reduction occurred at a Horizontal pipeline 12. 7 mm, temperature 41. 07 ° C, and a concentration of 0. 628 with a 1441. 84 flow rate was 25. 84%.

In the present study, the turbulent convective heat transfer and pressure drop characteristic of alumina (Al2O3) nanoparticle dispersions in water is studied experimentally in a Horizontal tube. The boundary condition imposed on the tube wall is that of uniform heat flux. Ten temperature sensors are also used to measure the surface temperature. One differential pressure transmitter (DPT) is employed to measure the differential pressure between inlet and outlet of the tube. A flow loop facility is constructed to conduct the experiments. To do this, Al2O3 nanoparticles of 40 nm size are characterized and dispersed in distilled water to form stable suspension containing 1.0%, 1.5% and 2.0% by volume concentrations of nanofluids. Results indicate that heat transfer coefficients increase with nanofluid volume concentration. The enhancement of the Nusselt number is about 22% at Re=13500 using 2% alumina nanoparticles compared to distilled water. The experimental data are also compared to predictions made by using the traditional single-phase convective heat transfer pressure drop in turbulent regime. The measured pressure loss when using nanofluids is almost equal to that of the base fluid.

In this paper, Turbulent mixed convective heat transfer of water and Al2O3 nanofluid has been numerically studied in a Horizontal tube under non-uniform heat flux on the upper wall and insulation in the lower wall using mixture model. For the discretization of governing equations, the second-order upstream difference scheme and finite volume method were used. The coupling of pressure and velocity was established by using SIMPLEC algorithm. The calculated results demonstrated that the convective heat transfer coefficient of nanofluid is higher than of the base fluid and by increasing the nanoparticles volume fraction, the convective heat transfer coefficient and shear stress on the wall increase. On the other hand, with increasing the Grashof number, the shear stress and convective heat transfer coefficient decrease.

BACKGROUND AND OBJECTIVES: Treatment of nasolacrimal obstruction is controversial. The purpose of this study was to compare the efficacy of dacryocystorhinostomy (DCR) with catheter intubation or bodkin tube in the treatment of nasolacrimal obstruction.METHODS: This Quasi- experimental study was conducted on patients with lacrimal obstruction who referred to the department of ophthalmology, Babol Medical University from 1999 to 2006. All cases were treated with DCR with intubation or Bodkin tube. Catheter or bodkin tube was drawn out 3 weeks and 4 months, respectively. After treatment all cases were followed at a 3 month interval for one year. Success rates in these two treated groups were compared. FINDINGS: In group DCR with catheter, 79 cases (50 females, 29 males) with the mean age of 34±16 years and in group bodkin tube, 103 cases (50 females, 53 males) with the mean age of 35±0.5 years were treated. The mean age and sex distribution among these two treated groups were equal (p=0.052). The success rate with DCR with catheter intubation was 96.2% and DCR with Bodkin tube was 99.1%. Significant difference was not seen between two groups in treatment failure.CONCLUSION: Dacryocystorhinostomy with catheter intubation or bodkin tube both have the same efficacy for treatment of nasolacrimal obstruction. However the efficacy of dacryocystorhinostomy with Bodkin tube is associated with lower recurrence rate but the difference was not significant.

Serous otitis or otitis media with effusion is one of the common diseases which if left untreated can lead to complications like tympanic membrane atrophy, cholesteatoma formation, behavioural changes, osteonecrosis and sensori - nueral deafness. One of the treatment options for serous otitis is VT placement which has its own complications like ottorhea, perforation and tympano - sclerosis. The rejection time of VT is closely related to the location of the ventilation tube. The complications arising due to VT placement are related to the time period since placement of the tube, social status of the patient, age, personal hygiene including prevention of water entry into the affected ear, etc. This prospective analytical survey with a one year follow up was carried out on children suffering from serous otitis who had been operated (VT placement) during the first half of 1378 at Shahid Rahnemom Hospital. Most of the VT rejections in all age groups occurred about 7-9 months after the operation but no significant difference was observed between the age groups. In the study determining the relation between gender and VT rejection time (P.V= 0.536), it was realized that the maximum number of VT rejections were between 3-6 months after the operation (47.7%) of which 44.3% was seen in boys and 51.9% in girls, thus, no significant difference was observed between the two sexes (P.V=0.691). 33.9% of the total had ottorhea. 35.1 % sclerosis, and 3.4% had a perforation. 27.6% of the patients had no complications. 7.7% of those patients who had a VT in the anterosuperior compartment of the tympanic membrane had a perforation, while only 2.7% of those who had a VT in the postero – interior compartment had a perforation. Age and gender have no effect on VT rejection time. The probability of a VT remaining in place is more in Shepherd type ventilation tubes than Richard type VT. Ventilation tubes placed in the antero - inferior quadrant are rejected earlier than those placed in the antero - superior quadrant. In the population under study, perforation is the least occurring complication in all age groups. There is on significant difference in the complications arising in either gender.      

Background and Aim: Using intra cranial reference lines is inherently unreliable for assessment of anterior-posterior jaw relationships. However, they are being widely used for cephalometric evaluation and diagnosis and treatment planning of orthodontic patient. The aim of this study was to evaluate the correlation of the TH/AB and TH-Wits to the common Horizontal and vertical analyses. Materials and Methods: This cross sectional descriptive study was conducted with 40 adults (20 male, 20 female) who were between 18-24 years-old and had no history of craniofacial disorders. Lateral cephalometries were taken for all patients, using Natural Head Position (NHP). All the cephalograms were taken by the same radiologist and were traced by same person. Two orthodontists approved the results and the kappa statistics was calculated to determin intra-examiner agreement level. Pearson correlation coefficient value was determined between TH-Wits, TH/AB and Horizontal parameters (Wits, Harvold, Wylie, APP-BPP, and ANB angle) and vertical parameters (Sn-GoGn, S-Go/N-Gn, TH-GoGn and sum of posterior angles). The correlation analysis was used in order to determine the relationship between these parameters. Results: The results revealed that the highest correlation in Horizontal direction was observed between TH-Wits, TH/AB; and ANB (0.73) and APP-BPP (0.68 & 0.61). In vertical direction, the highest correlation was demonstrated between TH-Wits, TH/AB; and sum of posterior angles (0.75 & 0.35). Conclusion: In using TH-Wits and TH/AB, the effect of changes in vertical dimension and the lack of significant correlation between these parameters and linear Horizontal analysis should be considered.

Enforcement of public policies is an important concern of most countries, especially developing countries. Weakness of Horizontal policy management and lack of coordination in enforcing these policies are obstacles to achieving this purpose. The article emphasizes on the increasing role of Horizontal coordination in Iran and other countries in the areas of accountability and good governance in government. Religious and national values, including consultation in matters, promotion of good and prevention of evil, and roles of justice and equity in Iranian Islamic society support this theory. Lacking a native Iranian-Islamic model of management and resistance of the state management system to fundamental changes are recognized as important obstacles to Horizontal coordination. The article also emphasizes on coordination between policy-making bodies in the national level, including the executive, judiciary and legislature, in order to achieving Horizontal coordination. Using administrative automation for making administrative systems transparent and attempting to operationalize morals and honesty and hard work based on religious values and national culture are suggested as strategies for strengthening Horizontal coordination within state.