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Numerical Study of Fan Coil Heat Exchanger with Copper-Foam
Ahmed M. Hassan,Adil Abbas Alwan,Hameed K. Hamzah 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.1
Due to its high porosity as well as a high specific surface area, the use of open cell metallic foam in heat transfer applications has received increasing interest. In present study, the dynamic and thermal performance of heat exchanger composed of copper foam incorporated in a fan coil was numerically analyzed. Darcy-Brinkman-Forchheimer model was used to represent the momentum equation inside the metallic foam (a porous medium). A local thermal equilibrium was used to solve the energy equation through the porous medium. Different porosity values were taken during the study, ranging from 0.88 to 0.98, while the velocity of inlet air of the heat exchanger ranged from 1 m/s to 10 m/s. The objective of current study is to compare the thermal and dynamic performance of the heat exchanger affected by several variables such as heat transfer coefficient, friction factor, pressure drop, Colburn factor, and area goodness factor. The results showed that increasing the air inlet velocity will increase the heat transfer coefficient, but on the other hand, increasing the velocity ten times will rise pressure drop from 19.032 Pa to 335.76 Pa. Also, the area goodness factor value will decrease with increasing inlet velocity. Finally, we found that increasing in medium porosity will reduce heat transfer coefficient but increase pressure drop
Corrosion Behavior Optimization by Nanocoating Layer for Low Carbon Steel in Acid and Salt Media
( Ahmed S. Abbas ),( Bahaa Sami Mahdi ),( Haider H. Abbas ),( F. F. Sayyid ),( A. M. Mustafa ),( Iman Adnan Annon ),( Yasir Muhi Abdulsahib ),( A. M. Resen ),( M. M. Hanoon ),( Nareen Hafidh Obaeed ) 한국부식방식학회 2023 Corrosion Science and Technology Vol.22 No.1
In this paper, a SiC nano electroless nickel plating layer with excellent corrosion resistance was fabricated using the Taguchi method. The electroless plated low carbon steel was subjected to tests to examine the influence of corrosive media, microhardness, and corrosion rate on the corrosion resistance of this alloy. Three different corrosive media (HCl, Na<sub>2</sub>SO<sub>4</sub>, and NaCl) at various temperatures (80, 90, and 100 ℃) were used, and at three different times (40, 80, and 120 min.) with a speed of stirring equal to 500 rpm. The results of microhardness were found from 134.276 HV to 278.578 HV at various conditions, while the corrosion rate results were obtained from 0.89643 mpy to 7.12571 mpy at different circumstances. Corrosion, and mechanical characteristics were explained using Taguchi design. Taguchi technique was used to account for all possible combinations of elements in order to conduct a complete study. Models that link the response and procedure parameters were developed using the results of these tests, and the analysis of variance was utilized to validate these models (ANOVA). For maximum efficiency, a function called “desirability” was applied to all responses at once.
Abbas, E.,Abelev, B.,Adam, J.,Adamová,, D.,Adare, A. M.,Aggarwal, M. M.,Aglieri Rinella, G.,Agnello, M.,Agocs, A. G.,Agostinelli, A.,Ahammed, Z.,Ahmad, N.,Ahmad Masoodi, A.,Ahmed, I.,Ahn, S. A. Springer Berlin Heidelberg 2013 The European physical journal. C, Particles and fi Vol.73 No.11
<P>The ALICE Collaboration at the LHC has measured the J/<I>ψ</I> and <I>ψ</I>′ photoproduction at mid-rapidity in ultra-peripheral Pb–Pb collisions at [FORMULA OMISSION].</P><P>The charmonium is identified via its leptonic decay for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 23 μb<SUP>−1</SUP>. The cross section for coherent and incoherent J/<I>ψ</I> production in the rapidity interval −0.9<<I>y</I><0.9, are [FORMULA OMISSION] and [FORMULA OMISSION], respectively. The results are compared to theoretical models for J/<I>ψ</I> production and the coherent cross section is found to be in good agreement with those models incorporating moderate nuclear gluon shadowing at Bjorken-<I>x</I> around 10<SUP>−3</SUP>, such as EPS09 parametrization. In addition the cross section for the process <I>γγ</I>→<I>e</I><SUP>+</SUP><I>e</I><SUP>−</SUP> has been measured and found to be in agreement with models implementing QED at leading order.</P>
Analyzing nonlinear vibrations of metal foam nanobeams with symmetric and non-symmetric porosities
Alasadi, Abbas A.,Ahmed, Ridha A.,Faleh, Nadhim M. Techno-Press 2019 Advances in aircraft and spacecraft science Vol.6 No.4
This article is concerned with the investigation of geometrically non-linear vibration response of refined thick porous nanobeams. To this end, non-local theory of elasticity has been adopted to provide the nanobeam formulation. Voids or pores can affect the material characteristics of the nanobeam. So, their effects have been considered in this research and also there are various void distributions. The closed form solution of the non-linear problem has been used that is adopted from previous articles. Then, it is focused on the impacts of non-local field, void distribution, void amount and geometrical properties on non-linear vibrational characteristic of a nano-size beam.
( Mervat Morsy Abbas Ahmed El-gendy ),( Naziha M. Hassanein ),( Hussein Abd El-hay Ibrahim ),( Doaa H. Abd El-baky ) 한국균학회 2017 Mycobiology Vol.45 No.2
The ability of dead cells of endophytic Drechslera hawaiiensis of Morus alba L. grown in heavy metals habitats for bioremoval of cadmium (Cd<sup>2+</sup>), copper (Cu<sup>2+</sup>), and lead (Pb<sup>2+</sup>) in aqueous solution was evaluated under different conditions. Whereas the highest extent of Cd<sup>2+</sup> and Cu<sup>2+</sup> removal and uptake occurred at pH 8 as well as Pb<sup>2+</sup> occurred at neutral pH (6-7) after equilibrium time 10 min. Initial concentration 30 mg/L of Cd<sup>+2</sup> for 10 min contact time and 50 to 90 mg/L of Pb<sup>2+</sup> and Cu<sup>2+</sup> supported the highest biosorption after optimal contact time of 30 min achieved with biomass dose equal to 5 mg of dried died biomass of D. hawaiiensis. The maximum removal of Cd<sup>2+</sup>, Cu<sup>2+</sup>, and Pb<sup>2</sup> equal to 100%, 100%, and 99.6% with uptake capacity estimated to be 0.28, 2.33, and 9.63 mg/g from real industrial wastewater, respectively were achieved within 3 hr contact time at pH 7.0, 7.0, and 6.0, respectively by using the dead biomass of D. hawaiiensis compared to 94.7%, 98%, and 99.26% removal with uptake equal to 0.264, 2.3, and 9.58 mg/g of Cd<sup>2+</sup>, Cu<sup>2+</sup>, and Pb<sup>2+</sup>, respectively with the living cells of the strain under the same conditions. The biosorbent was analyzed by Fourier Transformer Infrared Spectroscopy (FT-IR) analysis to identify the various functional groups contributing in the sorption process. From FT-IR spectra analysis, hydroxyl and amides were the major functional groups contributed in biosorption process. It was concluded that endophytic D. hawaiiensis biomass can be used potentially as biosorbent for removing Cd<sup>2+</sup>, Cu<sup>2+</sup>, and Pb<sup>2+</sup> in aqueous solutions.
Fenjan, Raad M.,Ahmed, Ridha A.,Alasadi, Abbas A.,Faleh, Nadhim M. Techno-Press 2019 Coupled systems mechanics Vol.8 No.3
Fee vibrational characteristics of porous steel double-coupled nanoplate system in thermo-elastic medium is studied via a refined plate model. Different pore dispersions called uniform, symmetric and asymmetric have been defined. Nonlocal strain gradient theory (NSGT) containing two scale parameters has been adopted to stablish size-dependent modeling of the system. Hamilton's principle has been adopted to stablish the governing equations. Obtained results from Galerkin's method are verified with those provided in the literature. The effects of nonlocal parameter, strain gradient, foundation parameters, porosity distributions and porosity coefficient on vibration frequencies of metal foam nanoscale plates have been examined.
Elnemr, Gamal M,El-Rashidy, Ahmed H,Osman, Ahmed H,Issa, Lotfi F,Abbas, Osama A,Al-Zahrani, Abdullah S,El-Seman, Sheriff M,Mohammed, Amrallah A,Hassan, Abdelghani A Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2
Triple-negative breast cancers constitute about 15% of all cases, but despite their higher response to neoadjuvant chemotherapy, the tumors are very aggressive and associated with a poor prognosis as well as a higher risk of early recurrence. This study was retrospectively performed on 101 patients with stage II and III invasive breast cancer who received 6-8 cycles of neo-adjuvant chemotherapy. Out of the total, 23 were in the triple negative breast cancer subgroup. Nuclear Ki-67 expression in both the large cohort group (n=101) and triple negative breast cancer subgroup (n=23) and its relation to the pathological response were evaluated. The purpose of the study was to identify the predictive value of nuclear protein Ki-67 expression among patients with invasive breast cancers, involving the triple negative breast cancer subgroup, treated with neoadjuvant chemotherapy in correlation to the rate of pathological complete response. The proliferation marker Ki-67 expression was highest in the triple negative breast cancer subgroup. No appreciable difference in the rate of Ki-67 expression in triple negative breast cancer subgroup using either a cutoff of 14% or 35%. Triple negative breast cancer subgroup showed lower rates of pathological complete response. Achievement of pathological complete response was significantly correlated with smaller tumor size and higher Ki-67 expression. The majority of triple negative breast cancer cases achieved pathological partial response. The study concluded that Ki-67 is a useful tool to predict chemosensitivity in the setting of neoadjuvant chemotherapy for invasive breast cancer but not for the triple negative breast cancer subgroup.
Knowledge and Opinions Regarding Oral Cancer among Yemeni Dental Students
Al-Maweri, Sadeq Ali,Abbas, Alkasem,Tarakji, Bassel,Al-Jamaei, Aisha Saleh,Alaizari, Nader Ahmed,Al-Shamiri, Hashem M Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5
Background: Oral cancer presents with high mortality rates, and the likelihood of survival is remarkably superior when detected early. Health care providers, particularly dentists, play a critical role in early detection of oral cancers and should be knowledgeable and skillful in oral cancer diagnosis. Purpose: The aim of the present study was to assess the current knowledge of future Yemeni dentists and their opinions on oral cancer. Materials and Methods: A pretested self-administered questionnaire was distributed to fourth and fifth year dental students. Questions relating to knowledge of oral cancer, risk factors, and opinions on oral cancer prevention and practices were posed. Results: The response rate was 80%. The vast majority of students identified smoking and smokeless tobacco as the major risk factors for oral cancer. Most of the students (92.6%) knew that squamous cell carcinoma is the most common form of oral cancer, and 85.3% were aware that tongue and floor of the mouth are the most likely sites. While the majority showed willingness to advise their patients on risk factors, only 40% felt adequately trained to provide such advice. More than 85% of students admitted that they need further information regarding oral cancer. As expected, students of the final year appeared slightly more knowledgeable regarding risk factors and clinical features of the disease. Conclusions: The findings of the present study suggest that here is a need to reinforce the undergraduate dental curriculum with regards to oral cancer education, particularly in its prevention and early detection.
Behavior and modeling of RC beams strengthened with NSM-steel technique
Md. Akter Hosen,Khalid Ahmed Al Kaaf,A.B.M. Saiful Islam,Mohd Zamin Jumaat,Zaheer Abbas Kazmi 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.88 No.1
The reinforced concrete (RC) structures might need strengthening or upgradation due to adverse environmental conditions, design defects, modification requirements, and to prolong the expected lifespan. The RC beams have been efficiently strengthened using the near surface mounted (NSM) approach over the externally bonded reinforcing (EBR) system. In this study, the performance of RC beam elements strengthened with NSM-steel rebars was investigated using an experimental program and nonlinear finite element modeling (FEM). Nine medium-sized, rectangular cross-section RC beams total in number made up for the experimental evaluation. The beams strengthened with varying percentages of NSM reinforcement, and the number of grooves was assessed in four-point bending experiments up to failure. Based on the experimental evaluation, the load-displacement response, crack features, and failure modes of the strengthened beams were recorded and considered. According to the experimental findings, NSM steel greatly improved the flexural strength (up to about 84%) and stiffness of RC beams. The flexural response of the tested beams was simulated using a 3D non-linear finite element (FE) model. The findings of the experiments and the numerical analysis showed good agreement. The effect of the NSM groove and reinforcement on the structural response was then assessed parametrically.