The non-traditional heat exchangers type effect on two phase heat transfer during evaporation process

Abed Alrzaq Sleman Alshqirate 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

Enhancement of heat transfer during the evaporation process investigated experimentally. Sub-cooled carbon dioxide flows inside nontraditional heat exchangers;micropipe heat exchanger with internal diameter of 0.6 mm and a porous tube one filled with gravel sand with porosity of 39.8 %. The experiments were carried out at different operating conditions. It is found that the heat transfer coefficient of the micropipe heat exchangers reached twice of the porous tube heat exchanger. Correlations utilized in the literature were used to validate experimental results. Good conformity was obtained.

Effect of Foliar and Root Application of Silicon Against Rice Blast Fungus in MR219 Rice Variety

Abed-Ashtiani, Farnaz,Kadir, Jugah-Bin,Selamat, Ahmad-Bin,Hanif, Ahmad Husni Bin-Mohd,Nasehi, Abbas The Korean Society of Plant Pathology 2012 Plant Pathology Journal Vol.28 No.2

Rice blast disease caused by Magnaporthe grisea (Hebert) Barr [teleomorph] is one of the most devastating diseases in rice plantation areas. Silicon is considered as a useful element for a large variety of plants. Rice variety MR219 was grown in the glasshouse to investigate the function of silicon in conferring resistance against blast. Silica gel was applied to soil while sodium silicate was used as foliar spray at the rates of 0, 60, 120, 180 g/5 kg soil and 0, 1, 2, 3 ml/l respectively. The treatments were arranged in a completely randomized design. Disease severity and silicon content of leaves were compared between the non-amended controls and rice plants receiving the different rates and sources of silicon. Silicon at all rates of application significantly (${\alpha}$ = 0.05) reduced the severity of disease with highest reduction (75%) recorded in treatments receiving 120 g of silica gel. SEM/EDX observations demonstrated a significant difference in weight concentration of silicon in silica cells on the leaf epidermis between silicon treated (25.79%) and non treated plants (7.87%) indicating that Si-fertilization resulted in higher deposition of Si in silica cells in comparison with non-treated plants. Application of silicon also led to a significant increase in Si contents of leaves. Contrast procedures indicated higher efficiency of silica gel in comparison to sodium silicate in almost all parameters assessed. The results suggest that mitigated levels of disease were associated with silicification and fortification of leaf epidermal cells through silicon fertilization.

COINCIDENCE AND FIXED POINT RESULTS FOR GENERALIZED WEAK CONTRACTION MAPPING ON b-METRIC SPACES

Abed Al-Rahman M. Malkawi,Abdallah Talafhah,Wasfi Shatanawi 경남대학교 수학교육과 2021 Nonlinear Functional Analysis and Applications Vol.26 No.1

In this paper, we introduce the modification of a generalized (Ψ, L)-weak contraction and we prove some coincidence point results for self-mappings G,T and S, and some fixed point results for some maps by using a (c)-comparison function and a comarison function in the sense of a b-metric space.

An Analytical Comparison of Single and Bi-layered Tube Hydroforming Systems Using Finite Element Method

Abed Alaswad,Abdul- Ghani Olabi 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Tube hydroforming is a type of unconventional metal forming process in which high fluid pressure and axial feed are used to deform a tube blank in the desired shape. Single and bi-layered tubular components can be produced by this method. In this paper, single and bi-layered tube hydroforming processes were numerically simulated using finite element method. It was found that the developed branch height resulted from the models was in good agreement with the experimental results. Both types of modeling have been kept with the same thickness, tube material, and process parameters to compare between the obtained hydroformed products (Branch height, Thickness reduction, and wrinkle height). Results were discussed.

Finite element modeling of the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes

Abed Nikkar,Saeed Rouhi,Reza Ansari 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.3

This study concerns the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes using the finite element method. The beam elements are used to model the carbon-carbon and silicon-carbon bonds. Besides, spring elements are employed to simulate the van der Waals interactions between walls. The effects of nanotube arrangement, number of walls, geometrical parameters and boundary conditions on the frequencies of nested silicon-carbide and carbon nanotubes are investigated. It is shown that the double-walled nanotubes have larger frequencies than triple-walled nanotubes. Besides, replacing silicon carbide layers with carbon layers leads to increasing the frequencies of nested silicon-carbide and carbon nanotubes. Comparing the first ten mode shapes of nested nanotubes, it is observed that the mode shapes of armchair and zigzag nanotubes are almost the same.

A new nonlocal HSDT for analysis of stability of single layer graphene sheet

Bouadi, Abed,Bousahla, Abdelmoumen Anis,Houari, Mohammed Sid Ahmed,Heireche, Houari,Tounsi, Abdelouahed Techno-Press 2018 Advances in nano research Vol.6 No.2

A new nonlocal higher order shear deformation theory (HSDT) is developed for buckling properties of single graphene sheet. The proposed nonlocal HSDT contains a new displacement field which incorporates undetermined integral terms and contains only two variables. The length scale parameter is considered in the present formulation by employing the nonlocal differential constitutive relations of Eringen. Closed-form solutions for critical buckling forces of the graphene sheets are obtained. Nonlocal elasticity theories are used to bring out the small scale influence on the critical buckling force of graphene sheets. Influences of length scale parameter, length, thickness of the graphene sheets and shear deformation on the critical buckling force have been examined.

New prismatic solid-shell element: assumed strain formulation and hourglass mode analysis

Farid Abed-Meraim,Alain Combescure 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.2

Effect of Foliar and Root Application of Silicon Against Rice Blast Fungus in MR219 Rice Variety

Farnaz Abed-Ashtiani,Jugah-Bin Kadir,Ahmad-Bin Selamat,Ahmad Husni Bin-Mohd Hanif,Abbas Nasehi 한국식물병리학회 2012 Plant Pathology Journal Vol.28 No.2

Rice blast disease caused by Magnaporthe grisea (Hebert)Barr [teleomorph] is one of the most devastating diseases in rice plantation areas. Silicon is considered as a useful element for a large variety of plants. Rice variety MR219 was grown in the glasshouse to investigate the function of silicon in conferring resistance against blast. Silica gel was applied to soil while sodium silicate was used as foliar spray at the rates of 0, 60, 120, 180 g/5 kg soil and 0, 1, 2, 3 ml/l respectively. The treatments were arranged in a completely randomized design. Disease severity and silicon content of leaves were compared between the non-amended controls and rice plants receiving the different rates and sources of silicon. Silicon at all rates of application significantly (α = 0.05) reduced the severity of disease with highest reduction (75%)recorded in treatments receiving 120 g of silica gel. SEM/EDX observations demonstrated a significant difference in weight concentration of silicon in silica cells on the leaf epidermis between silicon treated (25.79%) and non treated plants (7.87%) indicating that Si-fertilization resulted in higher deposition of Si in silica cells in comparison with non-treated plants. Application of silicon also led to a significant increase in Si contents of leaves. Contrast procedures indicated higher efficiency of silica gel in comparison to sodium silicate in almost all parameters assessed. The results suggest that mitigated levels of disease were associated with silicification and fortification of leaf epidermal cells through silicon fertilization.

Nonlinear Autoregressive with Exogenous Model to Diagnosis Aircraft Motor Faults Under Different Operating Conditions

Wathiq R. Abed,Muhanad A. Ahmed 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

Robust fault analysis (FA) including the diagnosis of faults and predicting their level of fault severity is necessary to optimize maintenance and improve reliability. This study aimed at presenting a technique to diagnosis faults of electronic switch in permanent magnet synchronous motor in Aircraft. The current output of both thyristor bridges and the diode of system excitation is monitored under healthy and faulty operations. Features extracted at diff erent operations using Multi-scale wavelet decomposition (MSWD) to extract the useful features. MSWD features are used to train nonlinear autoregressive with exogenous model which sequentially operated to evaluate the fault level in case open circuit that developing across a switch under diff erent operating condtions. The two models have been tested and designed due to the simulated data, where the results showed acceptable eff ectiveness in the diagnosis of various types of fault.

Particle Swarm Optimization-based dummy sub-carriers insertion for peak to average power ratio reduction in OFDM systems

Ahmed K. Abed,Riyadh Mansoor,Ali K. Abed 한국통신학회 2022 ICT Express Vol.8 No.1

Orthogonal Frequency Division Multiplexing (OFDM) is the best choice for wireless and wired high data rate communications. The OFDM system has many advantages such as high spectral efficiency, robustness to channel fading, and immunity to impulse interference. However, it has a main drawback, which is the Peak to Average Power Ratio (PAPR). Selecting Mapping (SLM) and Partial Transmit Sequences (PTS) are the two essential techniques for reducing the PAPR; however, they need to send side information to indicate how the transmitter generates signals. In this paper, Particle Swarm Optimization (PSO)-based dummy sub-carriers are inserted with the data to reduce PAPR without transmitting side information. The incorporation of PSO-based Dummy Sub-carriers Insertion (DSI) method on this system is performed by measuring the PAPR at the IFFT output (Inverse Fast Fourier Transform) after adding 6 adaptive sub-carrier sequences to the input data of IFFT. The PSO-based dummy algorithm decides to send the data once the PAPR of this data sequence and dummy sub-carrier is under a specific threshold. Using MATLAB as a mathematical simulation tool, simulation results are presented for a standard OFDM network model. The network model has been simulated in an Additive White Gaussian Noise (AWGN) channel environment to investigate PAPR and Bit-Error Rate (BER) performance. The simulation results show that the dummy sequence based on PSO reduces PAPR down to 4 dB compared to a conventional OFDM system and down to 3 dB compared with the clipping technique for the same BER performance.