Riyadh Faroq Halawani

Dr. Riyadh Faroq Halawani

King Abdulaziz University, Jeddah, Makkah al Mukarramah, Saudi Arabia
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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1 May 2022 in Journal of Saudi Chemical Society
Verified
Journal Article
Open access
MAMohamed A. Abdel-Fadeel
Mohamed A. Abdel-Fadeel
NANaif S. Aljohani
Naif S. Aljohani
SASaedah R. Al-Mhyawi
Saedah R. Al-Mhyawi
RHRiyadh Faroq Halawani
Riyadh Faroq Halawani
EAEnas H. Aljuhani
Enas H. Aljuhani
MSMohamed Abdel Salam
Mohamed Abdel Salam

17 January 2022 in Sustainability
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Journal Article
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MAMorzina Akter
Morzina Akter
RHRiyadh Faroq Halawani
Riyadh Faroq Halawani
FAFahed Aloufi
Fahed Aloufi
MTMd Abu Taleb
Md Abu Taleb
SASharmin Akter
Sharmin Akter
SMShreef Mahmood
Shreef Mahmood
The objective of this study was to utilize agro-lignocellulosic wastes for growing oyster mushroom which become problematic for disposal. Pleurotus ostreatus was cultivated on five agro-industrial wastes: rice straw (RS), wheat straw (WS), corncobs (CC), saw dust and rice husk @ 3:1 (SR) and sugarcane bagasse (SB). Approximately 500 g sized polypropylene bags (20.32 × 30.48 cm) were used for each substrate. The SR significantly improved the number of fruiting body (27.80), size of the fruiting body (5.39 g), yield (115.13 g/packet), ash and shortened the days for stimulation to primordial initiation and harvest (9.2 days). The maximum percentage of visual mycelium growth with the least time (15.0 days) to complete the mycelium running was found in SB, whereas the highest biological efficiency value (56.5) was calculated in SR. The topmost value of total sugar (33.20%) and ash (10.87 g/100 g) were recorded in WS, whereas the utmost amount of protein (6.87 mg/100 g) and total polyphenolics (196.88 mg GAE/100 g) were detected from SB and SR, respectively. Overall SR gave the highest amount of the fruiting body with the topmost polyphenols and ash, moderate protein and total sugar, and secured maximum biological efficiency too. The results demonstrate that saw dust with rice husk could be used as an easy alternative substrate for oyster mushroom cultivation.

Verified
Journal Article
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RHRiyadh Faroq Halawani
Riyadh Faroq Halawani
MWMyra E. Wilson
Myra E. Wilson
KHKenneth Hamilton
Kenneth Hamilton
FAFahed Aloufi
Fahed Aloufi
MTMd Abu Taleb
Md Abu Taleb
AQAndrew N Quicksall
Andrew N Quicksall
Red Sea coastal development has rapidly accelerated in recent decades that has led to a rise in the anthropogenic heavy metal levels in sediments. A total of 80 surficial sediment samples were collected from the shallow waters along the eastern Red Sea coast near Jeddah, Saudi Arabia. These samples were collected from three locations, designated as North, Middle and South of Jeddah, to assess the concentrations of six heavy metals: chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb). The results showed that the concentrations (mg/kg) of these metals in the studied sediments follow this order: Pb (77.34 ± 150.59) > Mn (36.52 ± 37.72) > Zn (18.02 ± 23.94) > Cr (9.56 ± 5.81) > Cu (9.18 ± 13.67) > Ni (3.68 ± 4.54). The majority of the polluted sediments were recorded in the Middle and South locations. Pollution and enrichment indices such as Geo-accumulation indices (Igeo), Enrichment Factors (Ef), Contamination Factors (Cf), Pollution Load Indices (PLI), Potential Ecological Risk Indices (PERI) and Potential Toxicity Response Indices (RI) were calculated from the measured metals to establish baselines for the region and assess specific metal enrichments by location along the Jeddah coastline. The Igeo values showed that 30% of the Southern location stations are considered moderately to highly polluted. The Ef for all the studied sediments followed this order: Pb (extremely severe enrichment) > Zn > Cu > Cd > Cr (severe enrichment) > Ni (moderate enrichment).

7 June 2023 in ACS Omega
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Journal Article
Open access
FAFahed A. Aloufi
Fahed A. Aloufi
RHRiyadh Faroq Halawani
Riyadh Faroq Halawani
bassem jamoussibassem jamoussi
bassem jamoussi
AHAmira K. Hajri
Amira K. Hajri
NZNesrine Zahi
Nesrine Zahi
In order to enhance the efficacy of organic solar cells, six new three-dimensional small donor molecules (IT-SM1 to IT-SM6) have been computationally designed by modifying the peripheral acceptors of the reference molecule (IT-SMR). The frontier molecular orbitals revealed that IT-SM2 to IT-SM5 had a smaller band gap (Egap) than IT-SMR. They also had smaller excitation energies (Ex) and exhibited a bathochromic shift in their absorption maxima (λmax) when compared to IT-SMR. In both the gas and chloroform phases, IT-SM2 had the largest dipole moment. IT-SM2 also had the best electron mobility, while IT-SM6 had the best hole mobility owing to their smallest reorganization energy for electron (0.1127 eV) and hole (0.0907 eV) mobility, respectively. The analyzed donor molecules' open-circuit voltage (VOC) indicated that all of these proposed molecules had greater VOC and fill factor (FF) values than the IT-SMR molecule. In accordance with the evidence of this work, the altered molecules can seem to be quite proficient for usage by experimentalists and have prospective use in future in the manufacture of organic solar cells with improved photovoltaic properties.

29 September 2021 in Biology
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MBMansour Balkhyour
Mansour Balkhyour
Abdelrahim HassanAbdelrahim Hassan
Abdelrahim Hassan
RHRiyadh Faroq Halawani
Riyadh Faroq Halawani
ASAhmed Saleh Summan
Ahmed Saleh Summan
Hamada AbdelgawadHamada Abdelgawad
Hamada Abdelgawad
Besides the lack of studies regarding applying elevated CO2 (eCO2) as a strategy to improve the chemical composition of anise (Pimpinella anisum L.) seeds, studies on its interaction with seed developmental stages and origin are very limited. The seed yield, chemical composition, and biological activity of 6 aniseed accessions (Egypt, Tunisia, Syria, Turkey, Yemen, and Morocco) were investigated during three developmental stages (immature, premature, and mature) under control and elevated CO2 conditions. Mature seeds from all aniseed accessions had significantly higher (p < 0.05) dry weight (DW) percentages than premature and immature seeds. The highest DW percentages were recorded in Egypt and Morocco accessions. Seed maturation increased nutrients and antioxidant metabolites in most eCO2-treated accessions. In contrast, essential oils were decreased by seed maturation, while eCO2 reversed this effect. Essential oil-related precursors (e.g., phenylalanine) and enzyme activities (3-Deoxy-d-arabino-heptulosonate-7-phosphate synthase (DAHPS) and O–methyltransferase) decreased with seed maturity. However, high CO2 reduced this impact and further induced the other essential oil-related precursors (shikimic and cinnamic acids). Consequently, eCO2 provoked changes in the antioxidant and hypocholesterolemic activities of aniseeds, particularly at mature stages. Overall, eCO2 application, as an efficient way to improve aniseed growth, essential oil metabolism, and chemical composition, was affected by seed maturation and origin. Future studies of eCO2-treated aniseeds as a nutraceutical and pharmaceutical product are suggested.

1 November 2022 in Water
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Journal Article
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Mohamed A. BarakatMohamed A. Barakat
Mohamed A. Barakat
RKRajeev Kumar
Rajeev Kumar
RHRiyadh Faroq Halawani
Riyadh Faroq Halawani
BABandar A. Al-Mur
Bandar A. Al-Mur
Moaaz SeliemMoaaz Seliem
Moaaz Seliem
Herein, magnetite nanoparticles (MNPs) synthesized from altered basalt were used to develop a composite with H2O2–activated bentonite (BE) and fibrous sawdust (SD). The as-prepared BE/SD–MNPs were characterized by FTIR, FESEM, TEM, TGA, DSC, and Zeta potential techniques and utilized as an effective multifunctional composite for removing methylene blue (MB). The adsorption isotherms of MB at 25–55 °C were analyzed via kinetics, classical, and advanced statistical physics models. Theoretically, the pseudo-second-order of kinetics and the Freundlich isotherms model fit the experimental data well without microscopically clarifying the adsorption mechanism. Studying a multilayer model’s steric and energetic parameters was a reliable approach to understanding the MB uptake mechanism at the molecular scale. Sterically, the removed MB molecules offered a combination of horizontal and vertical geometry (i.e., mixed orientation). The MB adsorption capacity at saturation (Qsat) increased from 829 to 849 mg/g with temperature, suggesting endothermic interactions. Energetically, the MB uptake by BE/SD–MNPs was controlled by physical interactions (i.e., adsorption energy < 20 kJ/mol). The BE/SD–MNPs retained more than 85% of the MB uptake after five adsorption-desorption rounds. Overall, this study aimed to understand the MB adsorption mechanism using a magnetic clays/lignocellulosic interface such as the utilized BE/SD–MNPs composite as a promising strategy in wastewater remediation.