Algerian Journal of Engineering and Technology

Neutron defect emulation using ion beam in zircaloy-4

Sat, 28 Dec 2024 00:00:00 +0100

The present study is devoted to study ion beam induced defects in zircaloy-4. We focused on the effect on the surface morphology modifications. The samples are first polished and then bombarded with 20 MeV Au ion and 0.7 MeV Cu ion at room temperature to a dose of 4.5 dpa. After irradiation the samples were subjected to chemical etching in 47 ml nitric acid (HNO3), 3 ml hydrofluoric acid (HF) and 50 ml water (H2O). Optical microscopy observation showed drastic changes in the microstructure after irradiation. The observation at the interface between the irradiated part and non-irradiated part revealed a clear shrinkage parallel to the ion beam direction. Fine grain of about 10 µm diameter are formed on the surface of zircaloy-4 irradiated at low energy (S_n/S_e << 1) while a hillocks-like nanostructure is observed in the case of high energy irradiation (S_n/S_e >> 1). Both cases can affect the zircaloy-4 corrosion resistance.

A Simulation and Analysis of I(V) and P(V) Characteristics of a Photovoltaic module under MATLAB/SIMULINK Connected to the Electrical Grid

Anouar benhaimoura, Aissa Souli — Sat, 28 Dec 2024 00:00:00 +0100

The objective of our work is the simulation and analysis of the I(V) and P(V) characteristics of a photovoltaic module under MATLAB/SIMULINK connected to the electrical network. To achieve this goal, we followed the following steps: At the start of work; we performed a simulation of a photovoltaic cell (photovoltaic module). By two methods: by simulation of the mathematical data of the model of a photovoltaic module inspired by the electrical diagram of a photovoltaic cell, by the use of the mathematical equations of: inverse saturation current, saturation current, photonic current, current of the shunt resistance, and the output current to create from each equation a model in MATLAB/SIMULINK, then we collect and connect these models according to the mathematical equation to obtain the final model of the output current of a photovoltaic module, and on the other hand by simulation through the model of the solar cell which exists in the SIMULINK library by checking the data of each box coming from this source. then we showed the Simulation of the BOOST converter with MPPT, and we presented the functional diagram of the PV generator and the BOOST converter with MPPT under MATLAB/SIMULINK, In the same context, we showed the voltage curve at the output of the command MMPT in MATLAB, the current curve at the output of the chopper booster, the curve of the voltage measured at the converter, the curve of the current measured at the converter, the curves of the phase currents of the network and the reference current, and the curve of PV generator power and Pmpp power At the end of the work, we connected this photovoltaic module to an electrical network, to see the impact of our network on the photovoltaic module and vice versa. Finally we explained and interpreted the results obtained according to our points of view.

Neutron irradiation effect on dielectic loss of bi-stretched polyethylene naphthalate

Sat, 28 Dec 2024 00:00:00 +0100

In the present work, the study of the evolution of the β^∗ process in both pristine and neutron irradiated bi-stretched polyethylene naphthalate films, is realized at a constant temperature and in the frequencies domain comprised between 10² and 10⁶ Hz by using the impedance spectroscopy technique. The results show the presence of dielectric loss peak determined in 10⁵ to 10⁶Hz frequency range, where the shape, position and the intensity are affected by morphological damage due to the large quantity of neutron beam energy transferred to the polymeric molecules that were highlighted by different structural analysis such as the Fourier transform infrared spectroscopy (FTIR) and the polarized light optical microscopy (PLOM). At room temperature, the FTIR technique showed an increase in the quantity of the carbonyl and naphthalene groups responsible of the presence of the Sub-Tg dielectric relaxation in the volume of the irradiated BSPEN (IR-BSPEN) film due to the amorphization phenomena traduced, respectively, by the absence and presence of the absorption bands characteristics of crystalline and amorphous phases. The PLOM characterization, revealed change in the texture of the IR-BSPEN surface indicating by the appearance of microcracks which contribute to the oxidation of macromolecular chains. The study of the effect of temperature on the dielectric behavior of non irradiated BSPEN film, in β^∗ region, showed that the dielectric parameters such as the maximum of dielectric losses and its position are thermally activated. This dielectric response has not identified in the case of irradiated BSPEN film, for which the evolution of losses with temperature change above T = 333K.

Effect of Using Recycled Fine Aggregate on Concrete Performance

arshd Y. Ismail, Ashtar S Al-Luhybi, Khalaf I. Mohammad — Sat, 28 Dec 2024 00:00:00 +0100

The practical use of recycled aggregate produced from crushing concrete waste in the production of new concrete reduces the consumption of natural aggregate and also reduces the amount of concrete waste that ends up in landfills. This study addresses the properties of concrete containing recycled fine aggregate (RFA) obtained from existing waste in Mosul. Four sets of concrete mixtures with different compressive strength (25, 30, 35 and 40MPa) were prepared, and for each strength, the effect of changing the replacement ratios of natural fine aggregate with recycled fine aggregate was studied, where four different ratios (0, 10, 20, 30)% of recycled fine aggregate (RFA) were adopted. The focus was on the compressive strength of concrete containing recycled fine aggregate due to the importance of this property as an indicator of concrete feature and the main determinant of its quality and the most important factor in design. The results showed a gradual decrease in the fresh properties of concrete containing recycled fine aggregate, such as slump and fresh density, as the proportion of recycled aggregate increased. However, there was an improvement in the compressive strength of the concrete mixes. Based on the practical results, equations were derived to predict the compressive strength of concrete containing recycled fine aggregate. According to the theoretical results obtained through analysis of variance (ANOVA), it was found that adding recycled fine aggregate at a rate of 20% is considered the best proportion, although the change in compressive strength is not significant.

Proposal for a standardized backplane interface board to support the development of future Algerian CubeSats

Elhabib Bensikaddour, Youcef Bentoutou, Aissa Boutte — Sat, 28 Dec 2024 00:00:00 +0100

The CubeSat standard provides access to space industries without the need to manufacture complex satellites requiring specific and costly resources. This type of satellite has proven its ability to accomplish several missions, namely, the demonstration of technology, scientific research, and even commercial missions. While various internal architectures exist for CubeSats, including PC104 and backplane configurations, the backplane approach offers superior modularity and simplicity. This makes it particularly suitable for collaborative development between organizations, especially universities. This paper proposes a standardized backplane architecture for future Algerian CubeSats, presenting both an internal configuration and a preliminary design for a backplane interface board. The proposed design enhances modularity, streamlines integration procedures, and provides a scalable foundation for Algeria's emerging CubeSat program. By establishing this standard, we aim to facilitate knowledge sharing and collaborative development within Algeria's space technology sector.