Abstract:We report on the development of UV range photodetector based on molybdenum disulfide nanocrystals (MoS 2 -NCs). The inorganic MoS 2 -NCs are produced by pulsed laser ablation technique in deionized water and the colloidal MoS 2 -NCs are characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and UV/VIS absorption measurements. The photoresponse studies indicate that the fabricated MoS 2 -NCs photodetector (MoS 2 -NCs PD) operates well within 300-400 nm UV range, with diminishing response at visible wavelengths, due to the MoS 2 -NCs absorption characteristics. The structural and the optical properties of laser generated MoS 2 -NCs suggest promising applications in the field of photonics and optoelectronics. field-effect transistors and the effect of ambient on their performances," Appl.

Thermomechanically processed high-strength steels feature specific fracture behavior. One of the decisive criteria for their application is their stability against internal defects during impact loads, especially in connection with the welding. The work is focused on experimental analyses of the influence of welding on static and dynamic fracture toughness of Strenx 700MC steel. The fracture toughness was determined using the circumferentially notched round bar specimens during static loads and two dynamic load levels. To achieve a homogeneous zone for the requirements of fracture toughness tests, simulation of the welding influence was performed. Fractographic and metallographic analyses described a specific fracture behavior controlled by the internal structural heterogeneity. A limiting degradation process due to welding was identified by the microstructural analysis.

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Generally, the determination of the wear in the mechanical systems is done by checking the critical components in periodic maintenance or by monitoring the secondary indicators such as vibration, noise, and temperature. These indicators can only be recognized after the wear reaches a certain level. In this study, an approach has been carried out on the use of the electromechanical impedance (EMI) method. In this study, EMI measurements were carried out depending on the different test samples, representing a different amount of wear level and wear location of the AISI 1040 steel block. The test samples were worn out in a controlled laboratory environment. The impedance measurements were taken before and after wear tests for each sample. Different measurements were made, and damage metrics were calculated and compared with the reference measurement made; the amount of the wear could be monitored primarily using the Root Mean Square Deviation (RMSD) method without dismantling the system. The location of wear could be determined by Correlation Coefficient Deviation (CCD) technique. In this study, it has been demonstrated that it could be possible to monitor the progress of wear in sensitive mechanical systems periodically without disturbing the integrity of the machine system.