The roll forming process plays a critical role in producing various sections used in industries. Also, the quality of these products is strongly affected by the thickness of the strip, the distance between stands, the section web, the flower pattern, and the plastic anisotropy. Therefore, the influences of practical factors on the bowing defect of the symmetrical Usection are experimentally and mathematically characterized in the present research. The investigated material is DC03 (1. 0347) steel. Different prediction models such as linear and non-linear model based on the general full-factorial design of experiment are used to predict the effect of following factors on the bowing defect. Accuracy of the analytical model was verified by comparing the output results with the practical data. Results show that the strip thickness of investigated material, the flower pattern, and the section web have the most significant effect on the bowing defect. Also, the anisotropic properties of the investigated material and the inter distance have the minor impact on the bowing defect, but the effect of material with considering the anisotropic properties on increasing the accuracy of process simulation results is very impressive and increases the accuracy of simulation results from 84% to 91%. Finally, the predicted bowing defect using the modified two-factor model was in 91% agreement with the experimental results.

Double-layer sheet forming methods are developed in various industries due to their dual properties and wide application. In this paper, the numerical and experimental investigation of the bowing defect in the flexible roll forming process of double-layer sheets have been discussed. Numerical analysis has been conducted using Abaqus finite element software and experimental tests using a single-station flexible roll forming machine. After validation of the numerical model, the effects of significant parameters on the bowing defect in the flexible roll forming process, including the forming angle, sheet thickness, sheet wing length, and the displacement of sheet layers have been investigated using full factorial design of experiments method and finite element simulations. The results were analyzed using the Analysis of Variance statistical method. The results showed that with increase of the forming angle and wing length, the amount of bowing defect increases while it decreases with the increase of the thickness of the sheet. Also, the arrangement of layers is also effective in the occurrence of the bowing defect. The results showed that the bowing defect in the Al-Cu layer material increased from 2.152 to 2.646 mm with the increase of the wing length from 18 to 25 mm.

FAs (Fuel Assembly) lateral deformation under mechanical, hydraulic, thermal, and radiation loads in the reactor core is called FA bowing. This phenomenon has different consequences for reactor safety and its operation. Bowing causes the local change in distance between the FAs, which leads to a neutron perturbation that affects the power distribution and its asymmetry. This research determines the bowing pattern of FAs in the VVER-1000 reactor core by using an artificial neural network and C-shape bowing assumption. That will be done based on power distribution caused by the presence of FA bowing. This issue will help the operator design the arrangement of FAs in the next cycle by knowing the bowing pattern in the reactor core. It will prevent the expansion of the bowing and its consequences in the next fuel cycles.

This article allocate to disabled people prayer and it surveys the bowing rule prayer in disabled people and MS patients. These people require bow sitting but they may be able to bow to the main form.The main purpose of this article is to answer this question: if the disabled people was able to stand before or after bowing, what’s his/ her duty? Should he/she bow sitting and then stand or should continue bowing to the same manner and stand after bowing or should be satisfied to sitting and appointed to sitting.The results show that standing attached to bowing is known as bowing and its necessary it compliances with the kind of bowing, but standing after bowing is an independent obligatory that if there is the ability for performing it, it should be do standing although the bowing has performed sitting.

The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD) effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites) the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.

Statement of Problem: The goal of bone regenerative therapy is to reconstruct the damaged tissues to initial condition, which seems so important in periodontology and implantology. In such therapies, different biomaterials, with some advantages and disadvantages, may by use.Purpose: The aim of this research was to evaluate the quality, bone trabecular density and thickness of newly forming bone as well as foreign body reaction against Biostite®, in comparison with the control group.Material and Methods: In this experimental study the total number of 5 sheep was operated with general anesthesia. At first 10 standard defects were created in 5x5x5 mm on the left and right edentulous mandibular ridge. Five defects were randomly treated by Biostite®, the remaining five were considered as controls. After six months, the sheep were sacrificed and the separated defect areas with intact margin were placed in 10% formalin and prepared for histologic and histomorphometric study. To analyze the data, Mann- Whitney U test was used.Results: The mean percentage of new bone formation in Biostite®group was statistically more han the control group (P<0.05). Newly formed bone was vital in both groups which was a combination of lamellar and woven types, however, the thickness and density of new bone in biostite® group was more than the controls. Foreign body reaction was observed in Biostite® group. Conclusion: It is suggested that Biostite® synthetic material can be useful in bone regenerative therapies.

Purpose: To evaluate 10 cases of corneal epithelial defect who were treated with cyanoacrylate glue temporary tarsorrhaphy.Materials & Methods: We used cyanoacrylate glue (razi supper glue) tarsocilliorraphy for the management of patients with corneal persistent epithelial defects (PED) with several etiologies who did not respond to other commercial treatments such as lubricants, artificial tears and patching. The cyanoacrylate glue was placed on the lateral one third of anterior lamella of lid margin and base of the cilia after preparastion with povidone iodine 5%, patients underwent a 14 days follow up for epithelial defect and tarsocilliorraphy prospectively.Results: 10 patients (8 males, 2 females) aged 52.1 (range: 12-81) years were evaluated prospectively after cyanoacrylate glue tarsocilliorraphy. Tarsocilliorraphy maintained 12.1 (range: 4-20) days and the mean period of epithelial defect healing was 11.2 (range: 3-20) days.Conclusion: We concluded the cyanoacrylate glue tarsocilliorraphy is an effective and safe method for the treatment of corneal persistent epithelial defect (PED) due to neurotrophic ulcer, exposure keratopathy and any epithelial defects not responded to commercial treatment.