الهه نحوی فرد

In recent years, some non-invasive methods have been developed to assess the state of health and disease of the skin and tissues. The evaluation of patients by the doctor in terms of skin complications and recovery after laser treatment is done visually and based on experience. Therefore, it is suggested to use quantitative and instrumental methods along with the visual evaluation dependent on the doctor. This research is designed with the aim of providing an optical system based on spectroscopy and the use of mobile phones to investigate the distinction between healthy and unhealthy tissue in order to monitor and investigate the process of skin disease.

Methods & Materials: 

Diffuse reflection spectrometry and spectrum-based imaging methods have been used in this research. Analysis of spectroscopic data from a skin lesion of blood vessels as a study, a spectroscopic imaging method is presented.

spectral data of the skin were analyzed and the difference between the absorption peak of the lesion with healthy skin and the skin with lesion was determined. In the following, using this distinction, the imaging system was proposed based on the results obtained from spectroscopy. This imaging system is a primary optical arrangement to obtain an image without mirror reflection and also to remove environmental factors such as ambient light. In fact, by choosing the index wavelength and lighting the lesion, it is possible to show a better distinction between that lesion and the surrounding healthy area. Also, in this system, a mobile camera is used as a detector.

After recording the image of the lesion and the healthy skin around it simultaneously in one image, image processing and quantification can be used to detect and check tissue changes.

A new modification to the Gilmore model is introduced to accurately simulate the effects of liquid shear and bulk viscosity and compressibility on the radial cavitation dynamics of a single bubble under a driving ultrasound field. Furthermore, in order to an accurate description of interior gas thermodynamics, a hydrochemical model, in which the heat and mass interchange across the bubble wall and also the chemical reactions are included, is used. The results of newly developed model are compared to those attained from the more practical Gilmore model. The simulations result for a single argon bubble in water show that neglecting the terms related to liquid viscosity and compressibility in the momentum conservation equation could affect the maximum temperature and pressure inside the bubble at the final moments of collapse. Under the conditions used in this study, the maximum pressure changes up %2. Moreover, the temporal evolution of water vapor particles meets the results obtained using the molecular dynamics simulation.

In this paper, ZrO2 thin films were grown on glass substrates using RF magnetic sputtering method. In ‎three separate experiments, three samples of ZrO2 film were prepared at various temperatures. Three ‎temperatures of  25 ̊C (laboratory temperature), 150 ̊C and 250 ̊C were selected for three samples, respectively. Except for temperature, other parameters ‎such as pressure, film growth rate, substrate to target distance and deposition time were the same for all ‎three samples. Optical properties and morphology of the samples were investigated. The morphology of ‎the samples was determined by atomic force microscopy (AFM) images and the ‎transmittance was measured using optical spectroscopy. The optical constants of the films were also ‎calculated using their spectrum. The results show that the effect of temperature is especially evident on ‎the optical properties of the films. As the temperature increases from the ambient temperature to ‎‎250 ̊C, the refractive index changes from n = 2.11 to n = 2.18. Moreover, increasing the ‎temperature, causes the absorption of the layer to increase. The morphology of the films also changes slightly ‎by changing temperature. The average roughness of all three samples is less than half a nanometer.‎.‎‎

Weak values of an observable can be found using weak measurements with pre- and post selections for target states. For example, when weak values are small, the expectation value of the pointer position (momentum) shows a shift proportional to the real (imaginary) part of the weak value. In this paper, we introduce the foundations of a new method for obtaining weak values that need not the weakness of the measurement. Using this method, not only the weak values of an observable but also weak values of all powers of the observable can be determined. The key point in this method is that instead of conditional expectation values of the device position and momentum in the standard method we use a complete set of marginal distributions to reconstruct device quantum state.