Alumina thin films have significant applications in the areas of optoelectronics, optics, electrical insulators, sensors and tribology. The novel aspect of this work is that the homogeneous alumina thin films were prepared in several stages to generate a plasma jet. In this paper, aluminium nanoparticles suspended in vinyl alcohol were prepared using exploding wire plasma. TEM analysis was used to determine the size and shape of particles in aluminium and vinyl alcohol suspensions; the TEM images showed that the particle size is 17.2 nm. Aluminium/poly vinyl alcohol (Al/PVA) thin films were prepared using this suspension on quartz substrate by plasma jet technique at room temperature with an argon gas flow rate of 1 L/min. The Al/PVA thin films were thermally converted to alumina films, where they were annealed at different temperatures (700, 800, or 900°C). X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques were used to characterise these thin films before and after annealing process. The diffraction patterns of the prepared thin films before subjecting them to the annealing process indicated the presence of peaks belonging to aluminium and PVA; however, the diffraction patterns and FTIR spectra obtained for these films after the annealing process showed peaks indicating the formation of alumina films of different phases. AFM and SEM investigations proved that the formed particles for all prepared films before and after the annealing process were similar in size and almost spherical; the diameter of the particles was on the order of a few nanometres. To control the properties of prepared thin films, the plasma which was used to produce thin films is diagnosed spectrophotometrically. The generated plasma was diagnosed using optical emission spectroscopy to estimate the electron temperature Te; the electron temperature was 1.925 eV.
In this paper, an adaptive active disturbance rejection control is newly designed for precise angular steering position tracking of the uncertain and nonlinear SBW system with time delay communications. The proposed adaptive active disturbance rejection control comprises the following two elements: (1) An adaptive extended state observer and (2) an adaptive state error feedback controller. The adaptive extended state observer with adaptive gains is employed for estimating the unmeasured velocity, acceleration, and compound disturbance which consists of system parameter uncertainties, nonlinearities, exterior disturbances, and time delay in which the observer gains are dynamically adjusted based on the estimation error to enhance est
... Show MoreThis review paper examines the crucial impact of YouTube on learning English as a Foreign Language. Recently, learners’ interaction and development of their skills have been improved due to the integration of digital platforms into language education. YouTube is regarded as one of the most prevalent platforms due to its accessibility, multimodal content, and capacity to simulate real-life communication. This study tackles thirty selected research articles from various cultural and institutional backgrounds to identify the pedagogical benefits and challenges associated with using YouTube in teaching English. Conventional methods of teaching English as a foreign language encounter difficulties in improving students’ engagement and
... Show MoreThe purpose of this study is to develop and assess the effectiveness of exercises using heavy and hanging ropes for handball players, focusing on enhancing specific physical abilities and shooting accuracy. The research addresses the gap in training methodologies by comparing the effects of heavy rope exercises versus hanging rope exercises. An experimental design was used in two equal groups, besides pre-testing and post-testing. The study involved 16 players from the School of Handball for the season 2022–2023. The sample included 14 players, who were then randomly divided into two experimental groups of 7 each. The first group performed heavy rope exercises, while hanging rope exercises were included in the plan of the second group. Th
... Show MoreEstimation the unknown parameters of a two-dimensional sinusoidal signal model is an important and a difficult problem , The importance of this model in modeling Symmetric gray- scale texture image . In this paper, we propose employment Deferential Evaluation algorithm and the use of Sequential approach to estimate the unknown frequencies and amplitudes of the 2-D sinusoidal components when the signal is affected by noise. Numerical simulation are performed for different sample size, and various level of standard deviation to observe the performance of this method in estimate the parameters of 2-D sinusoidal signal model , This model was used for modeling the Symmetric gray scale texture image and estimating by using
... Show MoreIn this work we study the influence of the laser pulse energy and ablation time on the aluminum nanoparticles productivity during nanosecond laser ablation of bulk aluminum immersed in liquid.
Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol for 3-8 minutes using the 1064 nm wavelength of a Nd:YAG laser with energies of 300-500 mJ per pulse.The laser energy was varied between 300 and 500 mJ/pulse, whereas the ablation time was set to 5 minutes. UV-Visible absorption spectra was used for the characterization and comparison of products.