Search

Your search keyword '"Ahmed, Yousif Mohamed"' showing total 3 results
Start Over Author "Ahmed, Yousif Mohamed"
3 results on '"Ahmed, Yousif Mohamed"'

1. Diode Clamped Multilevel Inverter Based on Arduino Microcontroller

Author

Othman Hassan Abdalla, Mohamed Alam-aldin Hassan, Muneeb Mustafa Saad, Ahmed Yousif Mohamed, Fatmaalzahra Abobakr Hassan, and Akram Mohammed Abdallah

Subjects
Microcontroller, Total harmonic distortion, business.industry, Computer science, Electrical engineering, Inverter, Digital control, business, Pulse-width modulation, Voltage, Power (physics), Diode
Abstract

This paper presents a single-phase Neutral point diode clamped (NPC) inverter module. Consists of single-cell connected to three equal DC power supply. This inverter also contains several semiconductor switches in which the process of direct voltage is reversed to the alternative wave in the output. In this paper, the modulation technique used is the level shift Sinusoidal Pulse Width Modulation (SPWM) technique, which allows controlling of semiconductor switches quickly. In the operation of generating and comparison of waves, the Arduino microcontroller was used. In the simulation examples, PSIM and Proteus programs were used, and the practical results were consistent exactly with simulation results.

Published
2021
Full Text
View/download PDF

3. ANTIOXIDANT ACTIVITY OF DIFFERENT PARTS FROM ANNONA SQUAMOSA, AND CATUNAREGAM NILOTICA METHANOLIC EXTRACT.

Author

Mariod, Abdalbasit Adam, Abdelwahab, Siddig Ibrahim, Elkheir, Sara, Ahmed, Yousif Mohamed, Fauzi, Putri Narrima Mohd, and Chuen, Cheah Shiau

Subjects
*ANTIOXIDANTS, *ANNONA, *PHENOLS, *REACTIVE oxygen species, *METHANOL, *PLANT extracts
Abstract

Background. We extracted phenolic compounds from Annona squamosa (leaves, bark, roots and seedcake), and Catunaregam nilotica (leaves, bark and seedcake) using methanol and their antioxidant activity was evaluated employing various established in vitro systems. Material and methods. Annona squamosa (leaves, bark, roots and seedcake), and Catunaregam nilotica (leaves, bark and seedcake) were used in the study. Antioxidant activity was estimated using oxygen radical absorbance capacity, MTT assay and DPPH assays, and polyphenols profi le was determined by HPLC method. Results. The total phenolic content was determined by Folin-Ciocalteu method and the highest amounts were 171.5, 170.4, 169.5, and 167.9 g/kg plant extract as GAE for A. squamosa roots, C. nilotica bark, C. nilotica leaves, and A. squamosa bark, respectively. The leaves extracts of the two trees showed high flavoniod content. The results showed that C. nilotica and A. squamosa extracts displayed antioxidant activities, with IC50 values ranging from 7.81 to 62.5 and from 7.81 to 125.0 µg/ml, respectively using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The different parts extracts from two trees showed good antioxidant activity evaluated by oxygen radical absorbance capacity and MTT assay systems. Conclusion. These results suggested that Annona squamosa and Catunaregam nilotica phenolic compounds could be utilized as a natural antioxidant. [ABSTRACT FROM AUTHOR]

Published
2012

Catalog

Books, media, physical & digital resources
See catalog results