Rahaf Ajaj

Dr. Rahaf Ajaj

Abu Dhabi University, Abu Dhabi, Abū Z̧aby, United Arab Emirates
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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13 June 2022 in Plants
Verified
Journal Article
Open access
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IHIslam Frahat Hassan
Islam Frahat Hassan
Rahaf AjajRahaf Ajaj
Rahaf Ajaj
MGMAYBELLE Saad Gaballah
MAYBELLE Saad Gaballah
COChukwuma C. Ogbaga
Chukwuma C. Ogbaga
Hazem M. KalajiHazem M. Kalaji
Hazem M. Kalaji
Shamel Mohamed Alam-EldeinShamel Mohamed Alam-Eldein
Shamel Mohamed Alam-Eldein
In Egypt’s arid and semi-arid lands where the main olive production zone is located, evapotranspiration is higher than rainfall during winter. Limited research has used nanomaterials, especially nano-silicon (nSi) to improve the growth, development, and productivity of drought-stressed fruit trees, amid the global water scarcity problem. To assess the role of nSi on drought-sensitive ‘Kalamata’ olive tree growth, and biochemical and physiological changes under drought conditions, a split-plot experiment was conducted in a randomized complete block design. The trees were foliar sprayed with nSi in the field using nine treatments (three replicates each) of 0, 150, and 200 mg·L−1 under different irrigation regimes (100, 90, and 80% irrigation water requirements ‘IWR’) during the 2020 and 2021 seasons. Drought negatively affected the trees, but both concentrations of nSi alleviated drought effects at reduced irrigation levels, compared to the non-stressed trees. Foliar spray of both concentrations of nSi at a moderate level (90% IWR) of drought resulted in improved yield and fruit weight and reduced fruit drop percentage, compared to 80% IWR. In addition, there were reduced levels of osmoprotectants such as proline, soluble sugars, and abscisic acid (ABA) with less membrane damage expressed as reduced levels of malondialdehyde (MDA), H2O2 and electrolyte leakage at 90% compared to 80% IWR. These results suggest that ‘Kalamata’ olive trees were severely stressed at 80% compared to 90% IWR, which was not surprising as it is classified as drought sensitive. Overall, the application of 200 mg·L−1 nSi was beneficial for the improvement of the mechanical resistance, growth, and productivity of moderately-stressed (90% IWR) ‘Kalamata’ olive trees under the Egyptian semi-arid conditions.

30 July 2024 in Horticulturae
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Journal Article
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Karim Mohamed HassanKarim Mohamed Hassan
Karim Mohamed Hassan
Rahaf AjajRahaf Ajaj
Rahaf Ajaj
AAAhmed Nazmy Abdelhamid
Ahmed Nazmy Abdelhamid
MEMohamed Ebrahim
Mohamed Ebrahim
IHIslam Frahat Hassan
Islam Frahat Hassan
Mahmoud Adel Ahmed AliMahmoud Adel Ahmed Ali
Mahmoud Adel Ahmed Ali
Silicon plays a crucial role in enhancing plant tolerance to various abiotic and biotic stresses, including drought, salinity, heavy metals, and pathogen/pest attacks. Its application has shown promising results in improving stress tolerance and productivity in medicinal plants. This review synthesizes findings from numerous studies investigating the mechanisms by which silicon confers stress tolerance, including the regulation of antioxidant systems, water relations, nutrient homeostasis, phytohormone signaling, and stress-responsive gene expression. Additionally, it examines the effects of silicon supplementation on the production of valuable secondary metabolites and essential oils in medicinal plants. Silicon application can significantly mitigate stress-induced damage in plants, including medicinally important species such as borage, honeysuckle, licorice, Damask rose, savory, basil, and eucalyptus. The deposition of silicon in cell walls provides physical reinforcement and acts as a barrier against pathogen invasion and insect herbivory. Furthermore, silicon fertilization can enhance the production of valuable secondary metabolites in medicinal crops under stress conditions. The findings underscore the potential of silicon fertilization as a sustainable strategy for improving the productivity and quality of medicinal crops under changing environmental conditions, highlighting the need for further research to elucidate the molecular mechanisms underlying silicon-mediated stress tolerance and practical applications in medicinal plant cultivation.

9 September 2021 in Sustainability
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Journal Article
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Christopher NWADIKEChristopher NWADIKE
Christopher NWADIKE
VJVictoria Ibukun Joshua
Victoria Ibukun Joshua
PDPaulina J. S. Doka
Paulina J. S. Doka
Rahaf AjajRahaf Ajaj
Rahaf Ajaj
UHUmmu Abubakar Hashidu
Ummu Abubakar Hashidu
Haruna Musa ModaHaruna Musa Moda
Haruna Musa Moda
Pesticides are known human and environmental toxicants, with an estimated 3 million cases of pesticide poisoning happening every year globally, resulting in more than 250,000 deaths. According to the existing literature, different pesticides groups are readily used among farmers in Nigeria. With recent developments around commercial farming, crop damage from pests, etc., this has led to higher consumption of pesticides among the farming community. The lack of product knowledge and safety awareness among this group further exposes them to the effects of pesticides. The study aims to measure Northern Nigerian farmers’ safety knowledge, awareness, and practices related to pesticide application. A cross-sectional study using an online survey questionnaire was adopted to generate responses from 524 farmers across the north-central and northeastern region of the country. Farmers’ attitudes towards pesticide use were driven by high crop yield, as 35.4% strongly agree that pesticide use is indispensable for high crop yield. The frequent use of empty pesticide containers for other secondary uses on the farm or at home, as confirmed by 30.6% of the participants, also presents safety and health concerns. Farmers’ age (p > 0.038) influenced pesticide containers use for other secondary purposes. In contrast, education attainment (p < 0.001) significantly influenced the use of pesticide containers for other farm or domestic uses. Farmers’ safety behaviours are influenced by socioeconomic factors, including educational level, age, and years of farm practice experience. The study concludes on the need to develop an approach that will help strengthen capacity-building programmes and enhance knowledge base initiatives around the adoption of non-synthetic pesticides.

12 April 2022 in Sustainability
Verified
Journal Article
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Rahaf AjajRahaf Ajaj
Rahaf Ajaj
WJWISAM ABU JADAYIL
WISAM ABU JADAYIL
HAHamna Anver
Hamna Anver
EAEman Aqil
Eman Aqil
According to studies on global plastic manufacturing and the resulting pollution, plastic wastes have been identified as a serious environmental concern. The impact of plastic garbage on marine species, humans, and the environment is a source of public concern, necessitating the need to save ecosystems and the lives that depend on them. Polyethylene terephthalate (PET) water bottles have a significant carbon footprint and represent tremendous waste. In the United Arab Emirates (UAE), PET water bottles are widely utilized, with yearly consumption reaching 450 water bottles per person. This study aims to review the literature on using PET water bottles in the UAE. A systematic literature search was conducted on journal articles, peer-reviewed journal articles, etc., published in the last 12 months. The main aspects of this systematic literature review include information on how plastic wastes are managed in the UAE and worldwide. In addition, it discusses the public health effects caused by plastic wastes, how the consumers of plastic bottles responded to the environmental policies, and so on. The article selection criteria included studies related to plastic water bottles in the UAE, waste management, environmental consequences, etc. A total of 30 articles were selected by initial screening, and 20 met the selection criteria and were included in the final review. To establish the credibility of this research, we understood that it was necessary to survey the UAE population to see the best approach to deal with PET water bottles.

26 May 2025 in Scientific Reports
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Journal Article
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Abdur RaufAbdur Rauf
Abdur Rauf
ZAZubair Ahmad
Zubair Ahmad
Rahaf AjajRahaf Ajaj
Rahaf Ajaj
HZHaiyuan Zhang
Haiyuan Zhang
MIMuhammad Ibrahim
Muhammad Ibrahim
IUImran Ullah
Imran Ullah
This study reports the plant extract-assisted synthesis of iron oxide (Fe3O4) using the aqueous extract of Thevetia peruviana. The synthesized IONPs were confirmed via UV–Vis spectroscopy (295 nm) and characterized using FTIR and SEM. Density Functional Theory (DFT) calculations indicated a thermodynamically and mechanically stable system with semimetallic behavior and visible light absorption. The biological activities of the IONPs were evaluated, including enzyme inhibition assays for urease, α-glucosidase, carbonic anhydrase-II, and xanthine oxidase, as well as anticancer activity. The Fe₃O₄ NPs exhibited potent enzyme inhibition, including urease (94.78%, IC₅₀ = 24.98 µg/mL), α-glucosidase (86.09%), and carbonic anhydrase-II (82.98%, IC₅₀ = 24.78 µg/mL). Additionally, molecular docking was performed to evaluate the interaction of Fe₃O₄ NPs with target enzymes, supporting their inhibitory potential. The NPs also demonstrated notable anticancer activity, particularly against MDR 2780AD (IC₅₀ = 0.39 µg/mL). These results showed significant enzyme inhibition and anticancer properties, indicating the potential of these green-synthesized IONPs in biomedical applications.

10 July 2023 in Sustainable Environment Research
Verified
Journal Article
Open access
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Rahaf AjajRahaf Ajaj
Rahaf Ajaj
RDRania Al Dweik
Rania Al Dweik
SAShafeeq Ahmed Syed Ali
Shafeeq Ahmed Syed Ali
MSMohammed Hashem Stietiya
Mohammed Hashem Stietiya
The unprecedented COVID-19 pandemic has caused socioeconomic, physical, mental, and environmental upheaval. Personal protective equipment, such as face masks, was mandatory to curb the spread of the virus. The unexpected increase in demand for face masks resulted in an alarming increase in plastic waste globally. The non-biodegradable nature of the raw materials and the potential threat of microplastic pollution amplify the problem. This puts a lot of pressure on policymakers and the global supply chain to develop long-term plans to make face masks less harmful. By reviewing existing life cycle assessment studies, this study aims to provide an overview on how sustainable face masks are. Various challenges in the facemask industry such as microplastic pollution and waste management are discussed. A critical analysis on the various process hotspots is also conducted. Recommendations from this study can motivate focused research into an important field and enable the transitions towards a sustainable facemask industry.