Purpose: The aim of this study was to compare higher-order aberrations between personalized TREATMENT (PT) versus personalized TREATMENT advanced (PTA) photorefractive keratectomy (PRK) for myopia and myopic astigmatism.Methods: In this clinical trial, 80 eyes of 40 patients who met inclusion criteria were enrolled. They underwent PRK using PT or PTA algorithm randomly. Higher-order aberrations were measured and compared between the study groups pre-operatively and at months 3 and 6 postoperatively.Results: The two study groups were comparable in terms of preoperative higher-order aberrations.Compared to the preoperative values, higher-order aberrations were significantly increased in the PT group (p<0.001), but decreased in the PTA group (p<0.001). Spherical aberration exhibited a significant increase postoperatively in the PT group (p<0.001) but remained unchanged in the PTA group (P=0.57).Conclusion: PRK using PT algorithm resulted in an increase higher-order aberrations. PTA algorithm provided better results in terms of postoperative higher-order aberrations and could treat pre-existing higher-order aberrations.

People with Parkinson's disease (PD) often have walking difficulty in the advanced stages of the disease and also suffer from balance problems. They perform their functional movements in a smaller range and at a slower rate, which will cause difficulty in performing daily activities. Patients with PD face many difficulties in outdoor activities, community participation, personal tasks, and fine motor skills (e. g. writing). They usually need the help of others. For two decades, a new TREATMENT called Lee Silverman Voice TREATMENT (LSVT) has been used by the speech therapists to treat speech and swallowing disorders in PD patients based on evidence and principles of neuroplasticity. The BIG protocol was added to this method in 2010 (LSVT-BIG). In this method, the whole body is involved and its main focus is on motor skills, which are guided by a physiotherapist and occupational therapist. The main goal of this new method is to improve patient’ s skilled movement in PD, as opposed to the old methods that introduce muscle stiffness as the main problem in these patients. In this method, patients will be required to perform a series of special exercises in sitting and standing positions in a larger range than usual with a specific schedule and in a one-month intensive period. Doing the BIG protocol correctly can make the range of motion softer and larger. The studies also show that the LSVT BIG method is very effective for improving patients' walking patterns and daily activities and significantly increases the quality of life in PD patients. Eventually, the PD patients will be able to perform their motor tasks automatically. Considering the useful results of this method and also the growing trend of its application around the world, it is necessary to enable therapists with this new method and provide more complete services for PD patients.

Introduction: Many efforts have been made to improve Ni-Ti alloy for endodontic use and it has been shown that surface properties and thus cutting efficiency of the rotary files can be improved by processes such as electro-polishing, ion implantation and surface coating. The aim of this study was to evaluate the effect of cryogenic TREATMENT on cutting efficiency of Ni-Ti rotary files.Materials and Methods: In this in vitro study, 60 Ni-Ti rotary instruments (Hero 642, #25, 0.04 taper) were selected and divided into 3 groups of 20. In group I no TREATMENT was used. In group II the instruments were subjected to a deep cryogenic TREATMENT in liquid nitrogen pool (-196oC) for 24 hours and after TREATMENT were immediately tested for cutting efficiency. In group III after cryogenic TREATMENT the temperature of the samples was raised slowly to room temperature for 24 hours. A new piece of test equipment was designed and used. The instruments were attached to the testing machine and rotated in Plexiglas samples for 10 seconds in a working length of 16 mm. The depth of grooves and weight loss of Plexiglas were measured after instrumentation. One-way and two-way ANOVA were used to compare the means of cutting efficacy between the three groups at 95% confidence interval.Results: The instruments which were immediately tested for cutting efficiency had significantly more weight loss and deeper grooves (pweight<0.001; pgroove=0.022), indicating better cutting efficiency. However, there was no significant differences between group I and group III in cutting efficacy (p weight=0.23; p groove=0.61).Conclusion: The results of this study showed that the surface properties of Ni-Ti alloy could be improved by the cryogenic TREATMENT for a limited period of time after TREATMENT, increasing the cutting efficiency of Ni-Ti rotary instruments.

Aqueous polymer quenchants are being used increasingly in steel HEAT TREATMENT industries as a substitution for conventional quenchants. By adjusting the quench parameters of the polymeric media, it is possible to achieve desirable microstructure and mechanical properties in addition to reduction in distortion and cracking. In this work, Polyalkylene Glycol (PAG) aqueous solution was used as the quenching medium in the HEAT TREATMENT of four grades of steels produced by Iran Alloy Steel Company including 1.7227, 1.6582, 1.1191 and 1.7765. In addition, the resultant mechanical properties of this procedure were compared with the properties of the specimens quenched in the conventional quenchants. The results showed that using polymer-based quenchants, the distortion and cracking can be minimized compared to water quenching. On the other hand, the mechanical properties which are not achievable by oil quenching can be obtained using polymeric quench medium.

AISI 301 stainless steel is a frequently used metal, especially in high temperature demands and or in part with high corrosion risk. Thin spring steel plates can be used as expansions of HEAT furnaces insulation and variety of all other springs. The present study has assessed the effects of temperature and thermal TREATMENT time span on the microstructure of stainless steel 301 to achieve elasticity and found out that microstructure gets smaller. As well as the Martensitic ά phase in the sample distributes uniformly after thermal TREATMENT at 450 ºC for 20 minutes then water quenched in 10ºC. By using X-ray diffraction, it can be found that the reduction in crystalline size of the Martensite ά and increasing in Martensite volume fraction is the cause of the elasticity of the samples. All obtained results confirmed by Ferittscope test.

One of the most problem during solidification of ductile iron is segregation of alloying element. Segregation of alloying element decreases mechanical properties of ductile iron and austempered ductile iron. In this research, alloying element profile as a function intergraphite distance was studied. Homogenization of ductile iron using partial melting is carried out, for first time, to homogenize the distribution of alloying element in the matrix of ductile iron. Results of image analyzer for homogenize and austember specimen showed that homogenization using partial melting against conventional homogenization, is very effective to uniform microstructure of ductile iron. The results show that morphology of graphite before and after homogenization using partial melting has minor effect on the morphology of graphite.

Manganese steels have extensively application in industries due to good resistance to wear, high work hardening capability with high toughness and ductility. HEAT TREATMENT is the main process to obtain desired mechanical properties and microstructure in this steel. The austenitizing temperature, the austenitizing time and the rate of quenching by increasing salt content are the main factors in HEAT TREATMENT. For dissolving of carbide, the austenitizing temperature and austenitizing time are very important. Quenching rate must be high for minimizing the grain boundary carbids. In this research the effects of these input parameters on the grain boundary carbide content, austenite grain size and hardness have been critically analyzed using Taguchi method. In the optimization by Taguchi approach, L9 (3)3 array, employing nine experiments, with three levels for each factor, was chosen for DOE. It has been found that the austenitizing temperature is the most important process parameter affecting the carbide content, grain size and hardness. The HEAT TREATMENT produces the minimum carbide content and low grain size when the process parameters were set at their optimum values. It has been shown that HEAT TREATMENT parameters set as their optimum levels can ensure significant improvement in the objectives.

In this paper the effects of experimental parameters on cyanide degradation in wastewater of HEAT TREATMENT units has been investigated. In this process, hydrogen peroxide and CU2+ are used as oxidizing agent and catalyst, respectively. In the First steep on the desired concentration of 100mg/l cyanide solution in alkaline condition at 25°c, the molarity of hydrogen peroxide and catalyst concentration were optimized. Experimental results show that in molar ratio of (H2O2 :CN-)9: 1 and CU2+concentration equal to 20mg/l, cyanide content decreases to less than 5mg/l in 30 minutes. The practical relevance of the laboratory degradation method is demonstrated for actual wastewater with 540 mg/l cyanide. In 100 minutes, the cyanide content of the wastewater was decreased to less than 5mg/l.

In this study, synthesis of silicon nitride by mechanical alloying and the effects of important parameters of milling time and HEAT TREATMENT temperature, time and rate are presented. Silicon micro powder and nitrogen gas were used as precursor materials. Synthesized phases, morphology and particle size were investigated by X-ray diffraction pattern (XRD) and Fieldemission scanning electron microscopy (FE-SEM), respectively. X-ray fluorescence analysis (XRF) was used for silicon nitride purity investigation.The optimum sample was produced at 30 h milling time, HEAT TREATMENT at 1300oC and 22 oC /min HEATing rate conditions. X-ray fluorescence analysis showed more than 98% purity.