Amal A Al Ghaferi

Amal A Al Ghaferi
Khalifa University | KU · Department of Materials Science and Engineering

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66
Publications
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1,396
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Publications

Publications (66)
Article
Full-text available
Rapidly declining costs of renewable energy technologies have made solar and wind the cheapest sources of energy in many parts of the world. This has been seen primarily as enabling the rapid decarbonization of the electricity sector, but low-cost, low-carbon energy can have a great secondary impact by reducing the costs of energy-intensive decarbo...
Article
Full-text available
Concentrating photovoltaics (CPV) have long been held up as a solution to low power density in photovoltaics, but due to the requirement of sun tracking have been largely unable to realize high power densities in practically useful settings. The emerging concept of tracking-integrated CPV, in which the sun tracking apparatus is incorporated into th...
Article
Plan-view transmission electron microscopy (TEM) or electron diffraction imaging of a bulk or layered material can provide detailed information about the structural or atomic arrangement in the material. A systematic and easily implementable approach to preparing site-specific plan-view TEM samples for layered materials using FIB is discussed that...
Article
Full-text available
Focused ion beam (FIB) technology has become a promising technique in micro- and nano-prototyping due to several advantages over its counterparts such as direct (maskless) processing, sub-10nm feature size, and high reproducibility. Moreover, FIB machining can be effectively implemented on both conventional planar substrates and unconventional curv...
Article
In this work, we study and characterize the layout-induced device strain and its impact on RF performance of 22-nm-ultrathin body and buried oxide fully depleted silicon-on-insulator (UTBB FDSOI) P-channel field-effect transistor (PFET). This will help in boosting and optimizing the RF performance for the targeted application. With shrinking device...
Article
Full-text available
Chemical vapor transport synthesis of SnTiS3 yields a self-assembled heterostructure of two distinct constituent materials, the semiconductor SnS and the semimetal TiS2. The misfit layer compound, although thermodynamically stable, is structurally complex, and precise understanding of the structure is necessary for designing nanoengineered heteroju...
Article
Full-text available
For the third time in a decade, solar energy pricing records are tumbling in the Persian Gulf. As each previous wave of new records was met with incredulity, only for these prices to become the new normal around the world within a few years, it would be unwise to once again dismiss low prices as unrepresentative outliers. In this study, we show how...
Article
In hostile environments, sensing is critical for many industries such as chemical and oil/gas. Within this industry, the deposition of scales or minerals on various infrastructure components (e.g., pipelines) forms a reliability hazard that needs to be monitored. Therefore, the approach adopted in this study to tackle this issue relies on the use o...
Article
In this work, a novel material based on carbon nanostructures (CNS), developed by Applied NanoStructured Solutions, was used with the goal of fabricating scalable CNS-based mats as an alternative to commercially available CNT-based mats. Statistical and experimental methods have been used to determine how the amount of surfactant and the sonication...
Article
Vertically aligned graphene nanosheet arrays (VAGNAs) exhibit large surface area, excellent electron transport properties, outstanding mechanical strength, high chemical stability, and enhanced electrochemical activity, which makes them highly promising for application in supercapacitors, batteries, fuel cell catalysts, etc. It is shown that VAGNAs...
Article
It has been experimentally demonstrated that a carbon nanostructure (CNS)-based structure, called CNS mats, can yield superior magnetic properties. The structure is obtained by decorating CNS with γ-Fe2O3 nanoparticles (NPs) in a three-dimensional (3D) network structure. γ-Fe2O3 NPs are coated on the CNS, resulting in enhanced magnetic properties....
Article
Full-text available
Modified Hummer’s method has been used in this study to synthesize graphene oxide (GO) solution that was utilized for the fabrication of three-dimensional (3D) graphene sponges and their subsequent functionalization through a low-cost and facile vapor-based surface enhancement approach. The functionalized 3D-graphene sponge is an excellent absorben...
Article
Full-text available
Surfactant-free grease made from carbon nanotube and carbon nanofibers has shown improvement in thermal conductivity. Time-dependent thermal conductivity (TC) magnetic study with different (Fe2O3 concentrations and Ni-coated carbon nanotubes) was performed. The results show that under the influence of a strong magnetic field, the TC value remains c...
Article
Treatment of graphene growth substrates with H2 has long been known to impact the quality of deposited graphene. However, the parameters for hydrogen treatment that are considered the optimum – very long anneals under low hydrogen concentrations – are often undesirable for practical reasons. In this paper we optimize anneal parameters for fast anne...
Conference Paper
Plasmonic nanostructures suspended in a liquid are known to offer enhanced absorption of light and improved photo-thermal efficiency comparing with conventional solar absorbers. This approach localizes high temperatures to the interior of the liquid through efficient trapping of incoming light via scattering and absorption mechanisms. Theoretical s...
Article
Formation of mineral scale on pipes, well bores and production tubing is a major issue for oil and gas industries that results in loss of production and reliability issues. Early warning of scale conditions is of great importance, since wells can scale up within 24 hours or less. Although multiple studies have been conducted on scale monitoring, mo...
Article
Full-text available
The effects of saline solution on the electrical resistance of single wall carbon nanotubes-epoxy nanocomposites have been investigated experimentally. Ultrasonic assisted fabricated 1.0% and 0.5 W/W% SWCNTs epoxy nanocomposites are integrated into a Kelvin structure by smear cast the nanocomposites on a glass wafer. Four metal pads are deposited o...
Chapter
The evolution of information and communication technologies in the last few years resulted in more demands for new data storage systems benefit from higher storage capacities. The new applications and devices in the market such as high definition TVs, iPADs, iPODs, Kindles, MP3s and smart phones operate through the storage of large amounts of data....
Article
In this paper, a new type of sensor and associated system for complete online monitoring of scale deposition with great accuracy and reliability is fabricated and characterized. The system is based on carbon nanotubes (CNTs), which have unique sensing/electronic properties along with physical and chemical stability in corrosive and hostile environm...
Article
Enormous amounts of research and development are currently underway in the arena of improving threedimensional graphene and graphene oxide networks for use as foams, sponges and aerogels for a wide range of applications. The underlying reason for the interest in 3D grapheme can be attributed to the splendid intrinsic and extrinsic properties brough...
Article
Full-text available
The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs), metal–insulator–semiconductor (MIS) and thin film transistor (TFT) structures, using poly(methyl methacrylate) (PMMA) as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate e...
Article
Scale is the creation of inorganic soluble salts from aqueous brines during oil and gas production, which deposits at the internal surface of the pipelines under the supersaturating conditions. Calcium carbonate (CaCO 3 ) and barium Sulphate (BaSO 4 ) are the most insoluble types of inorganic scale formed during the extraction of oil. The depositio...
Article
Full-text available
Despite the current interest in the scientific community in exploiting divergent surface properties of graphitic carbon allotropes, conclusive differentiation remains elusive even when dealing with parameters as fundamental as adhesion. Here, we set out to provide conclusive experimental evidence on the time evolution of the surface properties of h...
Article
Recently, Lockheed Martin Corporation has synthesized special types of carbon nanostructures (CNSs) that are made of highly aligned, but highly cross-linked, and relatively long carbon nanotubes that are bundled in flack-shaped architectures. In this paper, a simple and scalable method is developed for making very electrically conductive and mechan...
Article
We demonstrate that doping PEDOT:PSS hole transport layer (HTL) with fluorinated molecules has cumulative impacts on both charge extraction and optical constants within organic photovoltaic (OPV) devices. OPVs fabricated with modified HTL and two photoactive polymer blends led systematically to power conversion efficiencies (PCE) increases, with PT...
Article
Full-text available
We report a power law derived from experimental atomic force microscopy (AFM) data suggesting a nano to mesoscale transition in force-distance dependencies. Our results are in relative agreement with the Hamaker and Lifshitz theories for van der Waals forces for the larger tip radii only.
Article
Full-text available
In the present work, a free-standing paper-like sample made of a three-dimensional web of multiwall carbon nanotubes that exhibit cross-linking and wall sharing is characterized with respect to its electrical, electrochemical, surface and wetting properties. All these parameters are studied simultaneously to assess the potential of the sample for d...
Article
Full-text available
We report on the fabrication and characterization of hybrid-organic memory devices based on gold (Au) nanoparticles that utilize metal–insulator–semi-conductor structure. Au nanoparticles were produced by sputtering and inert-gas condensation inside an ultrahigh-vacuum compatible system. The nanoparticles were self-assembled on a silicon dioxide (S...
Article
Full-text available
Extensive work has been done in order to determine the bulk elastic modulus of isotropic samples from force curves acquired with atomic force microscopy. However, new challenges are encountered given the development of new materials constructed of one-dimensional anisotropic building blocks, such as carbon nanostructured paper. In the present work,...
Article
Full-text available
We report on the wettability alteration of graphitic surface using microscopic dynamic contact angle. Three different modified surfaces of Highly Ordered Pyrolytic Graphite (HOPG) were considered to assess the wettability of graphite in different conditions: Namely exposed surface to ambient environment, thermally aged specimen and freshly exfoliat...
Article
Full-text available
Conventional heat transfer fluids, such as mineral oil, water, and ethylene glycol, have poor heat transfer properties compared with solids. The methods to enhance the efficacy of heat transfer fluids have been of great interest to scientists and engineers for the past two decades. Recently, nanofluids are being considered as potential heat transfe...
Poster
Full-text available
Light absorbing plasmonic metal-dielectric nanoparticles suspended in water, or nanofluids have recently been experimentally demonstrated to produce steam at high efficiencies upon solar illumination. This approach localizes high temperatures to the interior of the liquid through efficient trapping of incoming light via scattering and absorption me...
Conference Paper
Full-text available
One of the main areas of improvement in capacitive deionization technologies is the materials used for electrodes which have very specific requirements. In the present work, a wide range of material characterization techniques are employed to determine the suitability of a multiwall carbon nanostructure thin film as electrode material. The electric...
Article
Utilization of nanotechnologies in condensation has been recognized as one opportunity to improve the efficiency of large-scale thermal power and desalination systems. High-performance and stable dropwise condensation in widely-used copper heat exchangers is appealing for energy and water industries. In this work, a scalable and low-cost nanofabric...
Article
Full-text available
The optimum concentration of surfactants in aqueous medium and the optimum sonication time for organic medium to achieve the best dispersion of SWCNTs are investigated in this study. Scanning electron microscope (SEM), atomic force microscope (AFM), and UV-vis-NIR study show that the optimum surfactant concentrations to achieve best dispersion for...
Conference Paper
Full-text available
In the present work, conductive atomic force microscopy is used to obtain high spatial resolution electrical characterization of a donor conjugated polymer, poly(3-hexylthiophene-2,5-diyl) blended with an acceptor fullerene derivative, 95% PC70BM ([6,6]-Phenyl-C71-butyric acid methyl ester) and 5% PC60BM ([6,6]-Phenyl-C61-butyric acid methyl ester)...
Article
Full-text available
Conductive atomic force microscopy (CAFM) is a valuable tool for electrical characterization of organic photovoltaics. However, the quantitative interpretation of the data is complicated by an apparent disagreement between the carrier mobilities calculated by CAFM and those determined by macroscopic measurements, with no apparent physical explanati...
Article
This manuscript spans over 180 years of ideas, discoveries, inventions, breakthroughs and research in Capacitive Deionisation (CDI) and Membrane CDI (MCDI) desalination. Starting with the first discovery of the dissociation of ions in solution under an electric field by M. Faraday (1833), through the pioneering work of carbon aerogel flow through c...
Article
Full-text available
Zinc oxide (ZnO) nanostructures (rods, ellipsoids and flowers) were synthesized using a zinc precursor and l-lysine in aqueous medium at room temperature and/or at elevated temperature. The average thicknesses of different zinc oxide nanorods samples synthesized by this eco-friendly route are in the range of 109 to 291 nm. The synthesized ZnO sampl...
Article
Zinc oxide (ZnO) flowers comprising nanorods of average size ∼160 nm were rapidly synthesized using l-lysine as a precipitating and capping agent in aqueous medium in the absence of hydrothermal conditions. When NaOH substituted lysine, formation of only ZnO stars was observed, proving the crucial role of lysine in forming nanorods. XRD analysis of...
Article
Full-text available
During their synthesis, multi-walled carbon nanotubes can be aligned and impregnated in a polymer matrix to form an electrically conductive and flexible nanocomposite with high backing density. The material exhibits the highest reported electrical conductivity of CNT-epoxy composites (350 S/m). Here, we show how conductive atomic force microscopy c...
Data
Further details on material fabrication (Figure S1), the conductive AFM setup (Figure S2), AFM tip-sample interactions (S3), AFM height and friction images (Figure S4), and the correlation between SEM and C-AFM imaging (Figure S5) are given.
Article
Full-text available
To investigate their memory behaviours, single-walled carbon nanotubes (SWCNTs) were embedded in the floating gate of a hybrid metal–insulator–semiconductor structure using layer-by-layer deposition, and polymethylmethacrylate (PMMA) as the dielectric. Unlike longer SWCNT-based structures, shortened SWCNTs were shown to exhibit reliable and large m...
Article
Full-text available
A microcontroller-based lock-in amplifier for sub-milliohm resistance measurements Rev. Sci. Instrum. 83, 075103 (2012) Note: Pneumatically modulated liquid delivery with feedback control Rev. Sci. Instrum. 83, 076102 (2012) Nonlinear conductance quantization effects in CeOx/SiO2-based resistive switching devices Appl. Phys. Lett. 101, 012910 (2012...
Article
Full-text available
Probing band-tail states in silicon metal-oxide-semiconductor heterostructures with electron spin resonance Appl. Phys. Lett. 100, 023503 (2012) High-performance short channel organic transistors using densely aligned carbon nanotube array electrodes Appl. Phys. Lett. 100, 023301 (2012) Pulsed metal organic chemical vapor deposition of nearly latti...
Article
Full-text available
Single-Walled carbon nanotubes (SWCNTs) were embedded in hybrid Metal-Insulator-Semiconductor (MIS) memory devices using layer-by-layer (LbL) deposition with polymethylmethacrylate (PMMA) as an organic insulator. It is demonstrated that shortened SWCNTs lead to reliable and large memory windows by virtue of better encapsulation which reduces charge...
Article
Full-text available
The elastic properties of a γ1-FePd single crystal have been measured using the pulse–echo overlap method. The anisotropic elastic constants of this tetragonal L10 structure are explained in part by the different bond strength between Fe–Pd neighbors compared with Fe–Fe and Pd–Pd neighbors. The tetragonal elastic anisotropy as measured for the sing...
Article
A yield strength anomaly has been observed in intermetallic L10-ordered FePd alloys between about 300-700K. However, previous work did not provide clear explanations regarding the microstructural or mechanistic origins for this observation. FePd and gamma-TiAl have the same crystal structure. YSA was studied intensively in gamma-TiAl system and its...
Chapter
This chapter discusses the evolution of magnetic properties and microstructure in cold-deformed equiatomic Fe-Pd during isothermal annealing at 500℃. The magnetic age hardening behavior has been determined using a vibrating sample magnetometer. The microstructures have been characterized by a combination of X-ray diffraction (XRD), scanning and tra...

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