Sound is one of the forms of mechanical energy and the two main characteristics of sound are intensity or power and frequency or wavelength of sound.their performance against the incoming sound wave, industrial silencers can be divided into two general groups of resonating and absorption silencers, the main difference between these silencers is the release of sound energy from the channeling system, which is one of the common examples of the use of resonating type silencers, their use in It is the internal combustion engines that distinguish absorption silencers from the resonator type based on the fact that the main and visible part of the act of muting the sound is achieved by changing sound energy to heat energy.The goal of this article is to design a muffler based on the breaking of sound frequencies resulting from the movement of fluid in the exhaust output of vehicles, which leads to a reduction of at least 50 db of sound and gives the operator enough peace and concentration. In this article, after examining three types of mufflers, absorbent mufflers that use the properties of porous absorbent material to absorb passing sound and are the simplest form of mufflers, have been selected, analyzed and reviewed and are suitable for the OM457 engine of Idem Industrial Company. It designed for maximum inlet exhaust temperature is 520 and for the maximum kW power is 315 with the maximum discharge relative pressure of 185 mbar for homogenization with the standard atmosphere.

Purpose: To compare the anatomical and functional results of deep vitrectomy with and without ILM peeling for full thickness macular hole.Materials & Methods: 37 eyes of 37 patients with full thickness macular hole (FTMH), confirmed by clinical examination and optical coherence tomography (OCT), enrolled in this clinical trial. Based on the stage of FTMH (stage 2, 3, 4) as described by Gass and the techniques of surgery (with or without ILM peeling) the patients were randomized into two different groups. All patients underwent preoperative Act and at least one OCT image was obtained during the postoperative follow up.After obtaining informed consent, deep vitrectomy and 20% SF6 injection was performed. The patients were unaware of their allocation status. Patients data & surgical outcome were collected and statistically analyzed. Anatomical success was defined as hole closure at postoperative OCT and functional success was referred to any improvement in visual acuity. Macular hole index (MHI) was defined as a ratio of the greatest height to the base diameter of the hole on cross-sectional OCT images.Results: 37 eyes of 37 patients (15 men & 22 women) were enrolled. The mean age of the patients was 56.4±21.94 years and FTMH were traumatic in 13 cases (35%) and Idiopathic in 24 (65%) cases. Twenty cases underwent deep vitrectomy with ILM peeling (ILM group) and the remaining cases underwent vitrectomy without ILM peeling (no ILM group).The mean preoperative 10gMAR visual acuity was 1.38±1 in the ILM group and 1.22±0.13 in the no ILM group, these improved to 0.95±1 and 0.77±0.31 postoperatively in the ILM and no ILM group, respectively (P=0.871). The overall anatomical success rate was 64%. The hole was closed in 70% of ILM peeling and 47% in the no ILM group (Chi-square test, P=0.15). In anatomically successful cases the mean of postoperative VA was significantly improved (P=0.001).In traumatic subgroup, ILM peeling seems did not affect the anatomical (P=0.2) and visual Success rates (P=0.5). There was no significant differences in hole closure rates between the traumatic and idiopathic FTMH (P=0.968). Visual acuity significantly improved after operation In MHI ³ 0.5 group compared with the MHk 0.5 group. The stage of the hole did not affect the anatomical success rate (P=0.52) or visual acuity improvement (P=0.741). Macular hole index ³ 0.5 had a prognostic value for postoperative visual acuity improvement. The hole duration was not related to anatomical success rate but there is an inverse relation between duration of the symptoms and improvement in VA.Conclusion: Deep vitrectomy and SF6 injection was a safe & effective surgical technique for full thickness macular hole and peeling of the ILM seems did not affect the anatomical or functional success rates. The hole duration, stage and origin of the hole (traumatic or idiopathic) does not related to the anatomical success or visual acuity improvement. MHI  ³ 0.5 seems to be a prognostic factor for postoperative visual improvement but not for closure rate.

Many tubular joints commonly found in offshore jacket structures are multi-planar. Investigating the effect of loaded out-of-plane braces on the values of the stress concentration factor (SCF) in offshore tubular joints has been the objective of numerous research works. However, due to the diversity of joint types and loading conditions, several quite important cases still exist that have not been studied thoroughly. Among them are internally ring-stiffened multi-planar XT-joints subjected to axial loading. In the present research, data extracted from the stress analysis of 81 finite element (FE) models, verified using experimental test results, was used to study the effects of geometrical parameters on the chord-side SCFs in multi-planar tubular XT-joints reinforced with internal ring stiffeners subjected to two types of axial loading. Parametric FE study was followed by a set of the nonlinear regression analyses to develop four new SCF parametric equations for the fatigue analysis and design of axially loaded multi-planar XT-joints reinforced with internal ring stiffeners.

The aim of present investigation was to evaluate the efficacy of the full thickness flap with internal mattress, suture in eliminating deep periodontal pockets in maxillary anterior region, to gain attachment and to preserve the height of the papilla prior to the periodontal surgery. Ten patients suffering from adult periodontitis in maxillary anterior region with minimum of two pockets;≥6mm were Participated in this study. Prior to the above surgery the first chase of therapy was performed the following clinical parameters1- Pocket depth2- Attachment level3- Height of papilla were measured one dayBefore the surgery and three months after the surgery. The total of 34 Pocket ≥ 6 mm was treated and the height of 224 papilla was measured. The mean difference between first two parameters. (Post surgical compare to pre surgical...) were 3.235 and 1.93 mm respectively which the differences were significant. Also the mean difference for the 3rd parameter was 1.305 mm which despite of being significant was acceptable (the differences between 3rd parameters less or closer to zero to be more acceptable. This technique is useful for eliminating pockets in maxillary anterior region.

During the 80s, Hilary Putnam developed a metaphysical viewpoint called 'internal realism'. Its slogan said, "the mind and the world together make up the mind and the world." According to Putnam, internal realism has two elements: 1) conceptual relativity and 2) seeing truth as idealized rational assertability. Here it will be argued that there is an internal incompatibility in the second element; i.e. truth as idealized rational assertability. To explain this incompatibility, firstly it will be shown that the idealization of rational assertability is duo to Putnam's emphasis on realistic intuitions of truth. Secondly, it will be shown that Putnam prefers to use 'sufficiently good conditions' instead of 'ideal conditions' to make a distinction between his idea and pierce's. Finally, it will be argued that some implication of 'sufficiently good conditions' is incompatible with those realistic intuitions of truth. Hence, one can conclude that there is an incompatibility in Putnam's attitude toward truth.

Scorpion sting is one of the serious problems for public health especially in Khuzestan province. The genus Hemiscorpius scorpions are a major factor to scorpion sting and its related death particularly in children. Eleven specimens of Hemiscorpius lepturus scorpion were collected from 6 regions of Khuzestan province and after identification, genomic DNA extraction was performed by manual method of phenol / chloroform. The Internal transcribed spacers (ITS2) genes with about 350 nucleotides was amplified by PCR and then sequenced using forward and reverse primers. The nucleotide sequence was compared using the nBLAST program available at NCBI Web site GenBank database. The results of the phylogenetic showed that the samples can be identified in two clusters A and B, with 85% correlation. Cluster A is subdivided into three subclusters A1 (including: H8, H9, H11M, H5, H44, H2 and H10), A2 (H22 and H4), and A3 (H10M). The specimens in these subclusters, showed a correlation between 54-85%. The studied sequences showed similarity (81. 7-98. 6%) with the only Hemiscorpius lepturus scorpion sequence (KU341981) recorded at the GenBank database beside a number of scorpions of the Hemiscorpionidae family. The only H9M scorpion specimen in cluster B with a relatively high genetic distance (11. 7– 19. 1%) was discriminated from the rest of the specimens, indicating that this specimen probably belongs to a subspecies different from the Hemiscorpius lepturus scorpion of Khuzestan province.