Abdul Hai Alami

Analytical and experimental evaluation of energy storage using work of buoyancy force

This paper presents theoretical formulation of, and experiments on a method of energy storage using the work of buoyancy force. The experiments proved that the energy storage using buoyancy force is an effective approach, as the experimental efficiency was found to exceed the theoretical estimation due to material properties of the buoys. The storage of mechanical energy without subsequent conversion into electrical energy has many advantages, including more compact storage setups, higher energy density retrieval, and higher efficiencies. For the current system, the efficiency of energy storage exceeds 37%. This value corresponds to earlier work by the author conducted for a single buoy, extending the prospects and applications of this approach to a better position in non-conventional energy storage applications.

Electrodeposited Dendritic Structures of Copper Oxide as Solar Selective Absorbers in the UV–Vis Range

We report the electrodeposition of copper from a 0.2 M H2SO4 + 0.4 M CuSO4 · 5H2O aqueous solution on a copper substrate, and its subsequent oxidation in air for selective solar thermal absorbers applications. A thorough study of the morphological properties and crystalline structure of the deposited layer through SEM-EDS and powder XRD revealed self-assembled dendritic microstructures, crystallized into fcc copper oxides, Cu2O. The building blocks of these dendrites are spherically-shaped particles of an average diameter of ca. 1 μm. The copper oxide layer was optically examined by virtue of a spectrometer in the spectral UV–Vis range. The surface roughness induced by the existence of the dendrites has been seen to enhance the absorptance of the material: fourfolds enhancement of optical surface absorption in the wavelength range of 400–1,000 μm versus an air-grown copper oxide.

Experimental Evaluation of a Buoyancy Driven Energy Storage Device

An experimental study on buoyancy driven-storage device is presented in the paper. The proposed device is forced to descend into a tank filled with a certain fluid the tension of a nylon wire that allows it to remain stationary at the bottom of the tank until the energy is needed. It is then released to reach the surface of the fluid liberating energy during that process. This paper also briefly presents the theoretical background and compares it with the experimental results. The application of this research is related to energy storage by non-conventional energy sources during off-peak timings. The experiments performed, have confirmed the validity of the approach and efficiency of the current system exceeds more than 40%. Other advantages like compact storage setups, higher energy density retrieval, longer life and low maintenance cost has made it more authentic than chemical storage devices.

Experimental and Numerical Investigations of a Compressed Air Energy Storage (CAES) System as a Wind Energy Storage Option

This paper presents an experimental evaluation of compact compressed air energy storage (CAES) system. The advantages of such a system are low cost, easy coupling with renewable resources (mainly wind energy), and high efficiency. While the system considered here is compact in size, the results obtained on the performance parameters, such as efficiency of energy conversion and expected electrical output, can be generalized for upscaling purposes. The main challenge with larger systems is the heat generated due to compression, which is not a major issue for the current system. Larger systems, however, enable operating at higher pressures, which means larger stored potential energy which in the case of 1 bar differential gave up to 13% higher kinetic energy.

Assessment of Photoelectrode Material Based on (TiO2)1-x / (Al65Cu24Fe11)x in Dye-Sensitized Solar Cell Applications

This paper presents the results obtained for incorporating the Al65Cu24Fe11 material with the conventional TiO2 as the electron injection layer in dye-sensitized solar cells. The icosahedral phase of the Al-Cu-Fe system has attractive physical and optical properties at the target composition, and is obtained by synthesizing the material via the facile high energy ball milling process to ensures the highest possible interdiffusion of elemental powders, followed by heat treatment. The evolution of the i-phase is confirmed via X-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy. The optical absorption and electrical properties of the compound are investigated by spectrometry, four probe measurement and Mott-Schottky analysis, respectively. Different cells with different percentages (x value) of (TiO2)1-x/(Al65Cu24Fe11)x are constructed and tested to obtain the electrical characteristic curves, efficiency and fill factor to quantify the effect of the proposed material mixture.

Bulk turbostratic graphene deposition on aluminum substrates via high-pressure graphite blasting

This work presents the mechanical exfoliation of graphite into graphene nanoplatelets via high-pressure blasting onto metallic substrates. After ensuring successful graphene deposition via Raman spectroscopy, the substrates are then tested to detect the enhancement of their thermal, optical, and electrochemical properties. The process is facile and straightforward, with no special requirements in terms of energy addition or isolation and is capable of depositing graphene over large surface areas. The application of such approach is especially suitable for solar thermal absorbers enhancement, as the thermal, optical, and corrosion resistance properties of metallic plates made of copper or aluminum benefit from the deposition at the macroscale.

Modelling and verification of an acrylic adhesive as a hyperelastic material

Abstract The development of a finite element (FE) model of an adhesive material is investigated with the help of experiments conducted on adhesively bonded metallic lap joints. Uniaxial tests of these joints were utilised to obtain hard points to bound the FE model and allow realistic representation of the mechanical properties of the adhesive material. Various convergence-enhancing options were activated within the software that aided in achieving convergence after each simulation run. The results were then verified by comparing experimental load-deflection results with FE ones, and conformance within ±17% was obtained.

Experiments on unfired masonry clay bricks mixed with palm fronds and date pits for thermal insulation applications

The limited resources on the planet have forced the rethinking of otherwise straightforward methods of building and selection of masonry materials. This research investigates using solid waste materials from the desert area and adding them to a clay matrix, and their effect on the thermal and mechanical properties of the resulting composite. Clay and fronds were mixed with pits of dates arranged horizontally, vertically, at 45° angles and crushed pits were compared to plain clay bricks in terms of mechanical and thermal properties. Although adding crushed pits greatly enhanced the mechanical properties of clay bricks, making them 85% tougher (greater area under the stress-strain diagram) and 15% stronger (ultimate stress), the composite did not display any enhancement in thermal properties, as the thermal conductivity remained in the range typical of sand and clay. Suitable applications for the composite would be as moulded pliable insulating sheets, or as a filler material.