Fahd Rajab

Dr. Fahd Rajab

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Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2016 in Journal of Nanomaterials
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FRFahd Rajab
Fahd Rajab
Anatase titania films with a thickness of up to 20 μm and deposited over a fluorine-doped tin-oxide substrate are impregnated with ruthenium dyes N-719 and N-749 using Dip and supercritical-fluid methods for the purpose of fabricating dye-sensitized solar cell devices. The dyes are dissolved in different solvent mixtures, including supercritical carbon dioxide, as well as combinations of more traditional solvents including mixtures of acetonitrile, and t-butanol. Analytical studies included thin-film analyzing and scanning electron microscopy to measure titania film thickness and porosity, UV-Vis spectroscopy to quantify dye concentration, and current-voltage device characterizations to assess energy conversion efficiency, as well as open-circuit voltage decay measurements and quantum efficiency to examine electron collection efficiency. A significant result is that using the dye N-749 in a solvent that includes supercritical carbon dioxide leads to energy conversion efficiencies that are higher for devices with a thick 20 μm semiconductor film than for the case of devices with thinner films, including the 10 μm film thickness that is traditionally considered an upper threshold. The supercritical-fluid method for the N-719 dye also enabled shorter impregnation duration than more conventional classical Dip Methods.
28 November 2022 in MRS Advances
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FRFahd Rajab
Fahd Rajab
1 June 2023 in AIP Advances
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AOAbdelbagi Osman
Abdelbagi Osman
FRFahd Rajab
Fahd Rajab
Observing the effect of temperature, concentration, and impurity on the crystal growth rate is accomplished by simulating the growth of sugar crystals. The volume diffusion growth model was used to examine the crystallization process and compare the effect of the three parameters on the growth of sugar crystals. The non-steady-state behavior of the process is examined using MATLAB simulation. A disturbance analysis of temperature, concentration, and impurity has been conducted to demonstrate their impact on the final crystal size of sugar. The findings show that temperature and impurities affect the final sugar crystal size. In addition, the size of crystals can be enhanced by increasing the concentration of sugar solution.
23 May 2023 in Processes
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KSKarlheinz Strobl
Karlheinz Strobl
FRFahd Rajab
Fahd Rajab
The super-growth approach for carbon nanotubes synthesis is frequently used to boost the growth rate, catalyst lifespan, and height of vertically aligned carbon nanotubes. The elimination of amorphous carbon from catalyst particles, commonly made of iron, by injecting water vapor into a chemical vapor deposition process can enhance the purity, alignment, and height of carbon nanotubes and prevent the partial oxidation of the metallic catalyst. We present the development of a modified growth-optimized water-assisted super-growth vertically aligned carbon nanotube process by optimizing the catalyst layer structure and water vapor concentration for a carbon nanotube growth process for 4” diameter Si wafers. A significant finding is that under optimized water-assisted growth conditions over 4 mm, highly uniform tall, vertically aligned carbon nanotube structures can be grown with a minimum top crust layer of about ~5–10 μm thickness. This was achieved with a catalyst film comprising a >400 mm thermal SiO2 layer on top of a 4” diameter Si wafer that was overcoated with an e-beam batch process run that first deposited a 20 nm SiO2 layer, a 10 nm Al2O3 layer, and a 1.1 nm Fe layer, in a 4-h growth process step.
4 July 2019 in Processes
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AOAbdelbagi Osman
Abdelbagi Osman
MEMohanad Eltayeb
Mohanad Eltayeb
FRFahd Rajab
Fahd Rajab
Energy demand and flue gas emissions, namely carbon dioxide (CO2) associated with the industrial revolution have exhibited a continuous rise. Several approaches were introduced recently to mitigate energy consumption and CO2 emissions by either grass root design or retrofit of existing heat exchanger networks (HEN) in chemical process plants. In this work, a combinatorial approach of path combination is used to generate several options for heat recovery enhancement in HEN. The options are applied to successively shift heat load from HEN utilities using combined utility paths at different heat recovery approach temperature (HRAT) considering exchangers pressure drop. Industrial case study for HEN of the preheat train in crude oil distillation unit from the literature is used to demonstrate the approach. The obtained results have been studied economically using the cost targeting of Pinch Technology. As a result, both external energy usage and CO2 emissions have been reduced from a heater device in HEN by 20% and 17%, respectively, with a payback of less than one year.
12 July 2023 in Ionics
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AZAbobakr K. Ziyada
Abobakr K. Ziyada
AOAbdelbagi Osman
Abdelbagi Osman
AEAbdalla Elbashir
Abdalla Elbashir
FRFahd Rajab
Fahd Rajab
AKAbdul Majeed Khan
Abdul Majeed Khan
CWCecilia Devi Wilfred
Cecilia Devi Wilfred