In this work the effect of preHEAT and POST weld HEAT TREATMENT on the properties of AISI 4140 steel was evaluated. The Experements were carred out on three different conditions:1-without preHEAT and without POST weld HEAT TREATMENT.2-with preHEAT and without POST weld HEAT TREATMENT.3-with pre HEAT and with POST weld HEAT TREATMENT. Welding process was SMAW. The effect of preHEAT and POST weld HEAT TREATMENT on mechanical properties was evaluated by mechanical testes such as impact test, tensile test, hardness test and bend test. The changing of microstructure was studied by optical microscope. With preHEAT and POST weld HEAT TREATMENT the mechanical properties of weld area should be controlled. The POST weld HEAT TREATMENT can improve the fracture toughness.

'POST-truth' has become a buzzword for numerous current crises: the fragmentation of the media landscape, the ongoing debate about 'fake news', the loss of trust in science, etc. Although these crises take place in society, it is claimed that the roots of POST-truth can be traced back to the history of philosophy. Occasionally, it is asserted that Karl Popper's critical rationalism gave rise to POST-truth: His rejection of verificationism has limited truth claims in the realm of science. Given the absence of infallible evidence and certainty, critical rationalism calls for challenging scientific authority. I argue that POST-truth is compatible with critical rationalism from an epistemological point of view, considering that both positions are critical of certainty. However, in critical rationalism, fallibilism, responsibility, and the idea of criticism are combined, and in this respect, it offers a possible way to overcome the problems that are associated with POST-truth. This TREATMENT of the problems of POST-truth results from the recognition of moral responsibility to take action on the basis of a hypothesis that remains open to revision.

In this study, the TiO2 nanorods were synthesized from P25 TiO2 nanoparticles by hydrothermal method in 10 M NaOH solution. The effects of annealing temperatures on produced nanorods were investigated by scanning electron microscopy (SEM) X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. Diameter growth and changes of surface oxygen defects of synthesized nanorods are studied with increasing annealing temperatures.

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.

Offering deposition of dense coating at solid state, cold spray consolidating method can be used for deposition of a wide variety of composite coatings including metal-matrix composite coatings. In this research, deposition of Ni-Ti composite coating using cold spraying and formation of intermetallics after POST spray HEAT-TREATMENT were investigated. Ni and Ti powders were physically blended with equivalent volume ratio (68. 3% at. Ni-31. 7%at. Ti), sprayed as the feedstock powder and composite coating with 35. 2 at. % Ni-64. 8 at. % Ti composition was obtained. POST HEAT-TREATMENTs were conducted at 740 ̊ C, 900 ̊ C, and two-step HEAT-TREATMENT 740 ̊ C and 960 ̊ C for different times. Microstructural investigation showed that all three equilibrium intermetallics of binary Ni-Ti phase diagram including Ni3Ti, Ti2Ni and NiTi phases were formed at all HEAT-TREATMENT experiments and fraction of Ni3Ti phase decreased with consumption of the Ni precursor. Additionally, it was found that cold sprayed composite coatings had fast intermetallics formation and growth kinetics compared with those of common press and sinter samples which was addressed through deformation enhanced interdiffusion and particle/particle bonding of cold sprayed coatings.

In this study, corrosion and mechanical properties of AISI 420 martensitic stainless steel after welding and HEAT TREATMENT were studied. HEAT TREATMENT cycle in order to optimize the mechanical and corrosion properties of the steel after welding was investigated. After TIG welding and HEAT TREATMENT of tempering, hardness and tensile, and impact mechanical tests and corrosion polarization tests were performed on the samples. Also to study the microstructure and identify the type of the happened corrosion, by optical microscopy and transmission electron microscopy (SEM), the samples were examined. By The results of mechanical tests and corrosion, HEAT TREATMENT conditions to achieve optimum mechanical properties and good corrosion properties was determined after welding. In conclusion, the cycle of HEAT TREATMENT of tempering at a temperature of 300˚ C and 1 hour, is an appropriate cycle in order to achieve Suitable corrosion and mechanical properties for welded 420 stainless steel.

9Cr-1Mo steel known for its improved mechanical properties such as low thermal expansion, excellent irradiation resistance to void swelling, high strength and good creep resistance and etc. are widely used for chemical, petrochemical, power generation and nuclear technology. The aims of this research were casting a kind of this steel in laboratory scale and modify its casting microstructure. After casting, for modifying the inhomogeneous and large grain structure, the samples were preHEATed at 1150oC followed by hot forge at 650oC with a strain about 1.5. Then deformed samples were annealed in g, g+α and α regions for different times. The effect of deformation and annealing parameters on micro structural characterizations and mechanical properties were studied with microscopically observation and mechanical testing. The optimum HEAT TREATMENT conditions after deformation for reach to fine and homogenous microstructure with desirable mechanical properties were annealing temperature about 900°C and anneling time about 120 minutes.

Modern political thought is a substratum of modern thought and affected by its results. What referred to as modern political thought is, in fact, in many respects a reconstructed form of modern insight in the field of politics. Thus we cannot speak of modern politics unless the philosophic aspects of modem affair is considered.In the present paper, one of the features of modern thought, that is, the tendency to a constant reconstruction of order and the concern for substituting the new order for the old one in order to prevent crisis has been studied. The absence of this doctrine among POSTmodern scholars is one of the important factors in this philosophic shift of POSTmodernism. In POSTmodern discourse, the perpetuity and inevitability of crisis are accepted as a principle, while the political administration for regulating and establishing the new order is overlooked.This distinguishes the POSTmodern approach to politics from that of the modern. This article examines the consequences of this attitude for the POSTmodern political thought and discusses political participation as an illustration of the issue beforehand.