Ahmed Telba

Dr. Ahmed Telba

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

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

Representative Publications

View All Publications
18 November 2023 in Heliyon
Verified
Journal Article
Open access
CLChanglin Li
Changlin Li
SASayed Ahmad
Sayed Ahmad
AAAhmad Bin Ahmad
Ahmad Bin Ahmad
MIMuhammad Irshad
Muhammad Irshad
ATAhmed Telba
Ahmed Telba
MMM Imran Majid
M Imran Majid
The study investigates the relationship between green production, green technology, waste reduction, energy use, and sustainability. A Partial Least Squares Structural Equation Modeling (PLS-SEM) approach was used for analysis. The data was collected from a sample of companies in the textile industry. The results suggest that green production and technology positively and significantly affect waste reduction and energy use, which mediates the positive relationship between these two factors and sustainability. This study concludes that green production and technology are critical drivers of sustainability and emphasizes the need to prioritize waste reduction and energy use in sustainable manufacturing practices. The study has practical and managerial implications in all production or manufacturing industries and provides a guideline for managers and policymakers to ensure sustainability.

20 April 2020 in Micromachines
Verified
Journal Article
Open access
PDF file
MKMuhammad Irshad irshad khan
Muhammad Irshad irshad khan
MKMuhammad Irfan Khattak
Muhammad Irfan Khattak
SRSaeed Ur Rahman
Saeed Ur Rahman
Abdul Baseer QaziAbdul Baseer Qazi
Abdul Baseer Qazi
ATAhmed Telba
Ahmed Telba
ASAbdel Sebak
Abdel Sebak
This paper proposes a compact, semi-circular shaped multiple input multiple output (MIMO) antenna design with high isolation and enhanced bandwidth for ultrawide band (UWB) applications. A decoupling stub is used for high isolation reaching up to −55 dB over the entire bandwidth. The proposed antenna is used for UWB as well as super wide band (SWB) applications. The overall size of the proposed antenna is 18 × 36 × 1.6   mm3. The | S 11 |   and voltage standing wave ratio (VSWR) of the proposed antenna are less than −10 dB and 2, respectively, in the range of 3–40 GHz. The total impedance bandwidth of the proposed design is 37 GHz. The VSWR, | S 11 | , | S 22 | , | S 21 | , | S 12 | , gain, envelope correlation coefficient (ECC), radiation pattern, and various other characteristic parameters are discussed in detail. The proposed antenna is optimized and simulated in a computer simulation technology (CST) studio, and printed on a FR4 substrate.

22 April 2024 in Sustainability
Verified
Journal Article
Open access
PDF file
Khaled A. MetwallyKhaled A. Metwally
Khaled A. Metwally
AOAwad Ali Tayoush Oraiath
Awad Ali Tayoush Oraiath
IEI. M. Elzein
I. M. Elzein
TETamer M. El-Messery
Tamer M. El-Messery
CNClaude Nyambe
Claude Nyambe
Abdallah Elshawadfy ElwakeelAbdallah Elshawadfy Elwakeel
Abdallah Elshawadfy Elwakeel
Date fruit drying is a process that consumes a significant amount of energy due to the long duration required for drying. To better understand how moisture flows through the fruit during drying and to speed up this process, drying studies must be conducted in conjunction with mathematical modeling, energy analysis, and environmental economic analysis. In this study, twelve thin-layer mathematical models were designed utilizing experimental data for three different date fruit varieties (Sakkoti, Malkabii, and Gondaila) and two solar drying systems (automated solar dryer and open-air dryer). These models were then validated using statistical analysis. The drying period for the date fruit varieties varied between 9 and 10 days for the automated solar dryer and 14 to 15 days for open-air drying. The moisture diffusivity coefficient values, determined using Fick’s second law of diffusion model, ranged from 7.14 × 10−12 m2/s to 2.17 × 10−11 m2/s. Among the twelve thin-layer mathematical models, we chose the best thin drying model based on a higher R2 and lower χ2 and RMSE. The Two-term and Modified Page III models delivered the best moisture ratio projections for date fruit dried in an open-air dryer. For date fruit dried in an automated solar dryer, the Two-term Exponential, Newton (Lewis), Approximation diffusion or Diffusion Method, and Two-term Exponential modeling provided the best moisture ratio projections. The energy and environmental study found that the particular amount of energy used varied from 17.936 to 22.746 kWh/kg, the energy payback time was 7.54 to 7.71 years, and the net CO2 mitigation throughout the lifespan ranged from 8.55 to 8.80 tons. Furthermore, economic research showed that the automated solar dryer’s payback period would be 2.476 years.

30 November 2023 in Fractal and Fractional
Verified
Journal Article
Open access
PDF file
Morsy NourMorsy Nour
Morsy Nour
Gaber MagdyGaber Magdy
Gaber Magdy
ABAbualkasim Bakeer
Abualkasim Bakeer
ATAhmed Telba
Ahmed Telba
Abderrahmane BeroualAbderrahmane Beroual
Abderrahmane Beroual
Hossam AliHossam Ali
Hossam Ali
Microgrids have a low inertia constant due to the high penetration of renewable energy sources and the limited penetration of conventional generation with rotating mass. This makes microgrids more susceptible to frequency stability challenges. Virtual inertia control (VIC) is one of the most effective approaches to improving microgrid frequency stability. Therefore, this study proposes a new model to precisely mimic inertia power based on an energy storage system (ESS) that supports low-inertia power systems. The developed VIC model considers the effect of both the DC-DC converter and the DC-AC inverter on the power of the ESS used. This allows for more precise and accurate modeling of the VIC compared to conventional models. Moreover, this study proposes a fractional-order derivative control for the proposed VIC model to provide greater flexibility in dealing with different perturbations that occur in the system. Furthermore, the effectiveness of the proposed fractional-order VIC (FOVIC) is verified through an islanded microgrid that includes heterogeneous sources: a small thermal power plant, wind and solar power plants, and ESSs. The simulation results performed using MATLAB software indicate that the proposed VIC scheme provides fast stabilization times and slight deviations in system frequency compared to the conventional VIC schemes. The proposed VIC outperforms the conventional load frequency control by about 80% and the conventional VIC model by about 45% in tackling load/RESs fluctuations and system uncertainty. Additionally, the studied microgrid with the proposed FOVIC scheme is noticeably more stable and responds faster than that designed with integer-order derivative control. Thus, the proposed FOVIC scheme gives better performance for frequency stability of low-inertia power systems compared to conventional VIC schemes used in the literature.

30 October 2020 in Micromachines
Verified
Journal Article
Open access
PDF file
MAMuhammad Ashraf
Muhammad Ashraf
KJKhalid Jamil
Khalid Jamil
ATAhmed Telba
Ahmed Telba
MAMohammed A. Alzabidi
Mohammed A. Alzabidi
ASAbdel Sebak
Abdel Sebak
In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed.

1 June 2005
Verified
Conference Paper
Closed access
ATAhmed Telba
Ahmed Telba
JNJ.M. Noras
J.M. Noras
MEM.A. El Eta
M.A. El Eta
BMB. Al Mashary
B. Al Mashary