The Role of Small and Medium Enterprises in Achieving Economic Goals of the Vision of Saudi Arabia 2030

Mohammed Ali Mohamed Ahmed ALI(Mohammed Ali Mohamed Ahmed ALI ),Ahmed Saied Rahama ABDALLAH(Ahmed Saied Rahama ABDALLAH ),SalimAhmed Mohamed AlSHEHRI(SalimAhmed Mohamed AlSHEHRI ) 한국유통과학회 2023 The Journal of Asian Finance, Economics and Busine Vol.10 No.2

This research aims to identify the role that small and medium enterprises (SMEs) can play in achieving the economic goals of the vision of Saudi Arabia 2030. The study relied on descriptive analysis, designing a standard model, and analyzing it using the Eviews9 program. The study also adopted the questionnaire as a tool for data collection. The study area covered Alkharj and Hawtat Bani Tamim governorates. The sample size of the study was 142 participants. The study’s results confirmed the existence of a significant impact of changes in independent variables (X1, X2, X3, X4), which are (GDP, non-oil exports, number of employees, and public revenues), respectively. The dependent variable (Y) represents the number of small and medium-sized businesses in the Kingdom of Saudi Arabia. Additionally, it was found that 61.3% of small and medium-sized enterprises in the governorates of Al-Kharj and Hawtat Bani Tamim operate in the commercial sector. Most study participants concur that SMEs significantly lowered the unemployment rate and helped boost the GDP rate in the Kingdom of Saudi Arabia. The obstacles and difficulties facing the establishment of these enterprises were financial problems, marketing problems, and corporate monopoly. Furthermore, most of the small and medium l enterprises faced financing problems.

Performance Comparison of Circular and Square RC Columns under Monotonic Loading Conditions

Ahmed Mohammed Youssef Mohammed,Ali Ahmed,Koichi Maekawa 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.1

Current flexural and shear design methods for reinforced concrete members are mainly based upon the rectangular cross-sectional shape. A simplified new approach for designing circular cross sectional Reinforced Concrete (RC) members might be to convert them to equivalent area, square shapes. An experimental study was performed on reinforced concrete circular cross sections and equivalent area, rectangular cross sectional members. The RC members were tested under non linear monotonic loading conditions, under both flexural and shear controlled conditions. Furthermore, the 3D FEM package COM3D was used to simulate the nonlinear performance of circular and its equivalent area, square members. Experimental and analytical results show that the circular RC members and its equivalent square have similar nonlinear performance (load-deflection behavior) in both flexural and shear controlled failure conditions. A good agreement was found in nonlinear performance of main design criteria; initial stiffness, flexural capacity, and shear capacity of both types. Based upon these results, the proposed approach can be considered satisfactory.

Micro-grid Monitoring and Supervision: Web-based SCADA Approach

Ali Mohamed A.,Barakat Mahmoud M.,Abokhalaf Masoud M.,Fadel Yasmin H.,Kandil Mohamed,Rasmy Mariam W.,Ali Osama N.,Besheer Ahmad H.,Emara Hassan M.,Bahgat Ahmed 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

Owing to the widespread use of the micro-grid concept to serve many real life applications, the main concern of this paper is to monitor, evaluate and manage the operational performance of an existent, already installed micro-grid that consists of On & Off grid PV systems in addition to the main grid supply. With the aid of customized web based SCADA system fully designed by authors, the performance evaluation of the proposed micro-grid is carried out in terms of energy consumption, power quality indices and energy cost based on Egypt’s energy current tariff . The designed system helps in both micro-grid status monitoring as well as load sharing between the main grid supply and the off grid PV energy system. The data of the on grid PV energy system are accessed and collected online directly from the inverter web server instead of downloading them offl ine from the PV inverter. In this case, data are analyzed with a reasonable refresh rate, which saves time and eff ort. Remote access platform is developed securely through a multi-level security authentication and strong data encryption using the OpenVPN protocol under the Dynamic Domain Name System service. Smart wired and wireless technology—used as integrated sensing devices to the developed SCADA system—enables easy system installation and running cost saving. Finally, to validate the collected data from the newly SCADA designed monitoring system, a performance characterization for the on grid PV system following international standards of yields calculations is carried out for 3 months in 2019.

Correlation of High Cycle Fatigue Behavior of Circular and Square Reinforced Concrete Columns Subjected to Shear Controlled Cyclic Loading

Ali Ahmed,Ahmed Mohammed Youssef Mohammed,Koichi Maekawa 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.5

In current design practice, mostly architectural needs govern the shape of reinforced concrete columns. There is a need to study and compare the load-deflection behavior and failure pattern of high strength reinforced concrete columns of different shapes. This paper presents a correlation between the performance of equivalent area circular and square columns subjected to shear controlled cyclic loading. Square and circular columns with equal cross-sectional area were experimentally tested in this research. Experimental results show that the maximum load, number of loading cycles and maximum deflection in case of square and circular columns were found to be close however, the final failure pattern was different. In case of columns without shear stirrups, the square column resisted 6.7% more loading cycles as compared to the circular column. However, the square column showed 19% lesser deflection at ultimate stage. In case of columns with shear stirrups, square column resisted only 9% more loading cycles as compared to circular column and exhibited similar ultimate deflection. The fatigue performance of equivalent area circular and square columns was found to be comparable in shear controlled conditions. However, the final failure pattern of circular columns shifted from shear to flexure near final failure.

Comparative Nonlinear Behavior of Corroded Circular and Square RC Columns

Ahmed Mohammed Youssef Mohammed,Ali Ahmed,Koichi Maekawa 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.7

This paper discusses performance of the reinforced concrete structures deteriorated by corrosion on basis of numerical simulation analysis. The purpose is to preliminarily investigate the idea of performance comparison of circular and square reinforced concrete columns under corroded conditions. Previous research carried out by the authors shows that equivalent area reinforced concrete (RC) columns exhibit similar load-displacement behavior under flexural and shear controlled conditions. The two types of columns deviate from this similarity after the corrosion of steel reinforcement present in the concrete. The change in the load-displacement behavior is highly dependent upon factors including the corrosion ratio, axial load, presence of web reinforcement etc., The experimentally verified 3D finite element modelling (FEM) program (COM3D) was used to investigate the seismic performance of the circular shaped and its equivalent area square shaped RC columns. The results show that the effect of mild corrosion (around 2% corrosion) on the load-displacement behavior of square RC columns is more significant as compared to circular RC columns at without axial load and at lesser main reinforcement ratio while a similar behavior or reverse trend is observed at higher main reinforcement ratios and for cases with 10% axial load. The effect of corrosion on the web reinforcement present in square columns is more pronounced as compared to circular columns at low main reinforcement ratios.

Optimum Controller Design Using the Ant Lion Optimizer for PMSG Driven by Wind Energy

Ahmed Lotfy Haridy,Al-Attar Ali Mohamed Abdelbasset,Ashraf Mohamed Hemeida,Ziad Mohamed Ali Elhalwany 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

The wind energy characteristics at the site not only indicate the amount of energy obtained from wind energy, but it also depends on the control strategy implemented on the wind energy conversion system. This study proposes an application of Ant Lion Optimizer (ALO) for tuning the classical (PI) controller parameters for the permanent magnet synchronous generator driven by wind energy system, to such an extent that the most maximum power point tracking can be acknowledged along with an improved fault ride-through capability. The optimized PI-controller parameters based ALO improving the low voltage ride through (LVRT) performance and the maximum power point tracking. ALO is implemented to the classical PI-controller on the machine side converter system, and grid side converter, for maximum power extraction from PMSG and enhancing LVRT. Four cases were considered in this paper, to examine the feasibility of the proposed ALO-PI controller. The suggested cases are system running at normal condition, a step-change in wind speed, wind speed variation at normal grid condition, and three-phase fault. A signifi cant improvement in the system dynamic performance when applying the ALO-PI controller is compared with classical PI-controller.

Gluteal Region Reshaping of Massive Weight Loss Patients—A Decision-Making Strategy

Mohamed Ali Mahgoub,Ahmed Mahmoud Zeina,Ahmed Mohamed Bahaa El-Din,Ahmed Hassan El-Sabbagh,Franco Bassetto,Vincenzo Vindigni 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.3

Background Massive weight loss (MWL) is a very common presentation that you may face as a plastic surgeon. Each patient has his own individual criteria, so, you should work according to a well-organized plan, especially when such cases have concerns about their gluteal area contour that were neglected before by many surgeons. A decision-making strategy was used to give a personalized treatment for targeting gluteal region reshaping of MWL patients. Methods This study considered all patients with MWL subjected to buttock reshaping. There was no randomization in treatment; there was a case-by-case assessment. We analyzed the features of the buttocks, the type of surgery performed, the outcomes, and the complications. Results Fifty two patients were included (41 females and 11 males), ages ranged between 21 and 66 years. Demographic data, preoperative body mass index (BMI), duration of surgery, type of surgery, and postoperative complications were collected. Statistically significant improvements were observed in gluteal ptosis and patient satisfaction grades. Conclusion Aesthetic improvement of the buttocks involves either augmentation or contouring that may be obtained by liposculpture, surgical lifting, or combination. Patients with MWL have high expectations and are often treated with multiple procedures. Thus, an easy strategic approach personalized on each patient to treat multiple adjacent areas in one operation is necessary. Adipose tissue distribution, gluteal skin status, and BMI were the main factors that can forcefully affect our plan to guarantee reduction of unpleasant results and complications and improve patient satisfaction.

Ultrasound-guided transversalis fascia plane block versus transmuscular quadratus lumborum block for post-operative analgesia in inguinal hernia repair

( Ahmed Zaghloul Fouad ),( Iman Riad M. Abdel-aal ),( Mohamed Rabie Mohamed Ali Gadelrab ),( Hany Mohammed El-hadi Shoukat Mohammed ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.2

Background: Inguinal hernia repair is one of the most commonly performed surgical procedures. Regional blocks might provide excellent analgesia and reduce complications in the postoperative period. We aimed to compare the postoperative analgesic effect of the ultrasound-guided transversalis fascia (TF) plane block versus the transmuscular quadratus lumborum (QL) block in patients undergoing unilateral inguinal hernia repair. Methods: Fifty patients enrolled in this comparative study and were randomly assigned into two equal groups. One group received an ultrasound-guided QL block. In comparison, the other group received an ultrasound-guided TF plane block. The primary outcome was the patient-assessed resting, and movement-induced pain on the numeric pain rating scale (NRS) measured at 30 minutes postoperatively. Secondary outcomes included the percentage of patients receiving rescue analgesia in the first postoperative day, ease of performance of the technique, and incidence of adverse effects. Results: There were no statistically significant differences in NRS at rest and with movement between the groups over the first 24 hours postoperatively. The proportion of patients that received postoperative rescue analgesics during the first 30 minutes postoperatively was 4% (n = 1) in the QL group compared to 12% (n = 3) in the TF group. However, the mean performance time of the TF block was shorter than that of the QL block, and the performance of the TF block appeared easier technically. Conclusions: The ultrasound-guided TF plane block could be as effective as the QL block in lowering pain scores and decreasing opioid consumption following nonrecurrent inguinal herniorrhaphy.

Bioprospecting of Culturable Halophilic Bacteria Isolated from Mediterranean Solar Saltern for Extracellular Halotolerant Enzymes

Ali Ahmed Mohamed,Abdel-Rahman Tahany M.A.,Farahat Mohamed G. 한국미생물·생명공학회 2024 한국미생물·생명공학회지 Vol.52 No.1

Halophilic bacteria are promising reservoirs for halotolerant enzymes that have gained much attention in biotechnological applications due to their remarkable activity and stability. In this study, 62 halophilic bacterial strains isolated from a solar saltern were screened for the production of various extracellular enzymes. The results revealed that 31 strains (50%) were positive for amylase production while 26 strains (41.9%) were positive for protease. Further, 22 strains (35.48%) exhibited β-glucosidase activity and only 17 (27.41%) demonstrated lipase activity. Of the investigated halophiles, ten strains growing in the presence of ≥15% NaCl (w/v) were selected and identified based on their 16S rRNA gene sequences as Halomonas meridiana, Salinivibrio costicola, Virgibacillus oceani, Virgibacillus marismortui, Marinobacter lipolyticus, Halobacillus karajensis, Salicola salis, Pseudoalteromonas shioyasakiensis, Salinicoccus amylolyticus, and Paracoccus salipaludis. Therefore, the present study highlights the diversity of the culturable halophilic bacteria in a Mediterranean solar saltern, harboring various valuable halotolerant enzymes.

NUMERICAL STUDY OF THE COMBUSTION CHARACTERISTICS IN A SYNGAS-DIESEL DUAL-FUEL ENGINE UNDER LEAN CONDITION

Abubaker Ahmed Mohammed Mohammed Ali,Kabbir Ali,Changup Kim,Yonggyu Lee,오승묵,Kiseong Kim 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.5

The aim of this study was to investigate the combustion characteristics of a syngas-diesel dual fuel engine operates in very lean fuel-air mixture conditions. 3D CFD simulation combined with chemical kinetics were used for analysis. The main parameter for this study was the hydrogen content in the syngas. To simulate the combustion for the dual fuel engine, a new dual-fuel chemical kinetics set was used that was constituted by merging the two chemical kinetics sets: n-heptane (173 species), and Gri-mech 3.0 (53 species) for natural gas. The calculation results were in good agreements with the experimental results. Most of the diesel fuel burned as premixed combustion mode. When the hydrogen concentration was high, as in syngas45, most of the syngas in the piston bowl and squish region, except near the cylinder wall, was combusted in the vicinity of TDC; but when hydrogen concentration was low, as in syngas25, flame propagation to the central region of the piston was delayed, which led to an increase of time loss and unburned syngas emission. Due to the strong reverse squish flow, the syngas composition did not affect the flame arrival time at the cylinder wall through the squish area by much.