Simultaneous reduction and sulfonation of graphene oxide for efficient hole selectivity in polymer solar cells

Asghar Ali,Zuhair S. Khan,Mahmood Jamil,Yaqoob Khan,Nisar Ahmad,S. Ahmed 한국물리학회 2018 Current Applied Physics Vol.18 No.5

We developed sulfonated, reduced graphene oxide (S-RGO) through fuming/concentrated sulfuric acid treatment of graphene oxide (GO) in ambient conditions. It was demonstrated that the optical band gap and electrical conductivity of S-RGO are easily tunable, and depend on the level of reduction and sulfonation of GO. Whereas, reduction and sulfonation were found dependent on SO3 content, acid strength, and gas tightness of the reaction mixture. It's actually the water content of oleum that determines the nature of the final product. The easily adjustable band gap and electrical conductivity suggest that S-RGO can be employed as a potential hole extraction layer (HEL) material for several donor-acceptor systems. For P3HT:PC61BM based inverted polymer solar cells, it was observed that the shape of the JeV curve is tailorable with the choice of HEL. Compared to a 2.75% power conversion efficiency (PCE) attained with PEDOT:PSS, a PCE of 2.80% was achieved with tuned S-RGO. Our results imply that an S-RGO of sufficiently high band gap and conductivity can replace some of the state of the art HEL materials for a host of device applications.

Synthesis of New Pyrazole, Triazole, and Thiazolidine-Pyrimido [4, 5-b] quinoline Derivatives with Potential Antitumor Activity

Ameen Ali Abu-Hashem,Ahmed S. Aly 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.3

2-Hydrazinyltetrahydropyrimido [4, 5-b] quinolin-4(3H)-one (3) was prepared by desulfurization reaction of S- and N-dimethyl derivatives 2 with hydrazine hydrate. Reactions of (3) with malonitrile, carbondisulfide, potassium thiocyanate, phthalic anhydride and aromatic aldehydes afforded 3, 5-di aminopyrazolopyrimido [4, 5-b] quinoline (4), triazolotetrahydropyrimido [4, 5-b] quinoline (5), aminotriazolopyrimido [4, 5-b] quinoline (6), aminophthalimidopyrimido [4, 5-b] quinoline (7) and N-arylidene hydrazinepyrimido [4, 5-b] quinoline 8a-d, respectively. Furthermore, 8a-d reacted with mercaptoacetic acid gave the thiazolidinonepyrimido [4, 5-b] quinoline 9a-d, which afforded the thiazolotriazolopyrimido [4, 5-b] quinolinone 10a-d upon treatment with ethanolic potassium hydroxide. The newly synthesized compounds were characterized by elemental analyses, IR, 1H-NMR, 13C-NMR and mass spectrometer. The investigated compounds were screened for their cytotoxicity. Compounds 4, 6 and 5 exhibited potent antitumor activity.

Investigations of thermoelectric properties of different gallium nitride polytypes through first-principles approach

Ul Haq Bakhtiar,Kim Se-Hun,Alsardia M.M.,Khadka I.B.,Chaudhry Aijaz Rasool,AlFaify S.,Ahmed R.,Shah Zulfiqar Ali 한국물리학회 2023 Current Applied Physics Vol.49 No.-

In recent years, exploring new polytypes of III-V semiconductors has been widely practiced for the development of thermoelectric devices of high efficiency. In this work, the thermoelectric properties of new polytypes, namely the wurtzite(wz), Berrylium oxide (β-BeO), Nickel arsenide (NiAs), Silicon carbide (SiC), and Titanium arsenide (TiAs) phases of GaN have been investigated using the first-principles approaches. It is found that the p-type of doping induces enhancement of the power factors (PFs) and figure-of-merits (zT) of the GaN polytypes. The optimal p-type doping for PFs has been recognized as - 1.67 eV for wz-GaN, - 1.78 eV for β-BeO-GaN, - 1.33 eV for NiAs-GaN, - 1.58 eV for SiC-GaN, and - 1.48 eV for TiAs-GaN. These optimal p-type doping has induced the room-temperature PFs as high as 13.75 × 1010 W/mK2s recorded for wz-GaN, 13.61 × 1010 W/mK2s for β-BeO-GaN, 41.14 × 1010 W/mK2s for NiAs-GaN, 14.06 × 1010 W/mK2s for SiC-GaN, and 49.21 × 1010 W/mK2s for TiAs-GaN. Furthermore, the PFs of the GaN polytypes are enhanced by increasing the temperature. Due to such significant PFs, the zT values corresponding to p-type doping have been recorded as 1.013 for wz-GaN, 0.998 for β-BeO-GaN, 1.00 for NiAs-GaN, 1.015 for SiC-GaN, and 0.999 for TiAs-GaN. Moreover, we comprehensively discussed the electrical and thermal conductivities and Seebeck coefficients (S) for the predicted GaN polytypes. The results of the thermoelectric properties presented in this study reveal the predicted GaN polytypes may find interesting applications in thermoelectric devices for clean energy harvesting.

Numerical desirability function for adsorption of methylene blue dye by sulfonated pomegranate peel biochar: Modeling, kinetic, isotherm, thermodynamic, and mechanism study

Ali H. Jawad,Ahmed Saud Abdulhameed,M. A. K. M. Hanafiah,Zeid A. AlOthman,Mohammad Rizwan Khan,S. N. Surip 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.7

Sulfonated pomegranate (Punica granatum) peel biochar (SPPBC) was developed via thermal activation with sulfuric acid (H2SO4) to act as a promising biochar material for the adsorptive removal of toxic cationic dye namely methylene blue (MB) dye from contaminated water. A Box-Behnken design (BBD) and numerical desirability function were adopted to optimize the input adsorption variables (SPPBC dosage, temperature, pH, and contact time). The maximum removal of the MB dye can be accomplished by simultaneous significant interaction between SPPBC dosage with solution pH, SPPBC dosage with time, SPPBC dosage with temperature, solution pH with time, and time with temperature. The numerical desirability function identified the highest MB dye removal (93.9%) can be achieved at the following optimum numerical adsorption conditions: SPPBC dosage 0.18 g, temperature 49 oC, pH 9.7, and time 4.3 h. Equilibrium data were well fitted to the Temkin and Langmuir isotherm models. The maximum recorded adsorption capacity of SPPBC for MB dye adsorption by using Langmuir isotherm model was 161.9mg/g. This research work reveals the possibility of converting lignocellulose pomegranate peel into a renewable and environmentfriendly biochar via a relatively fast acid-activation process with the great potential to be promising adsorbent for removal of MB dye.

Surface Modified of Cellulose Acetate Electrospun Nanofibers by Polyaniline/β-cyclodextrin Composite for Removal of Cationic Dye from Aqueous Medium

Ahmed S. M. Ali,M. R. El-Aassar,F. S. Hashem,N. A. Moussa 한국섬유공학회 2019 Fibers and polymers Vol.20 No.10

This paper concerns with the enhancement of a safe and clean procedure for remediation of water pollution. Cellulose acetate (CA) nanofibers were prepared via electrospinning technique prior to surface modification with polyaniline/β-cyclodextrin (PANI/β-CD) nanocomposite. Morphology and structure of the modified CA nanofibers were characterizedby different analysis like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electronmicroscopy (SEM) and Thermogravimetric analyses (TGA). We studied the influence of modification of CA with PANI/β-CD nanocomposite for removal of cationic dyes from colored aqueous solution in dynamic batch mode. Methylene blue(MB) dye was selected as a cationic dye model for the study. The effects of various parameters like pH, nanosorbent dose,dye concentration and reaction time on the adsorption capacity were studied. Some mathematical isotherm and kineticmodels have been utilized to investigate the adsorption mechanism of MB into the CA-PANI/β-CD nanofibers. Thereusability of the CA-PANI/β-CD nanofibers was also verified in sequent cycles and rapid process was detected. Differentreal water samples like tap water, industrial wastewater, municipal wastewater and sea water were applied to test the MBremoval efficiency.

The bio-composites (Hydroxyapatite/High-density polyethylene) materials reinforced with Multi-walled carbon nanotubes for bone tissue repair

Ali A. Al-allaq,Jenan S. Kashan,Mohamed T. El-Wakad,Ahmed M. Soliman 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.4

Due to the predominance diseases such as bone fracture, bone cancer, and osteoporosis Worldwide. There is a developingrequirement for synthesizing biomaterials for bone repair or substitute due to the predominance of bone fracture, bone cancer,and osteoporosis. In this study, multi-wall carbon nanotubes (MWCNT) of (0.6%, 1%, 1.4%, 2%) wt.% and High-densitypolyethylene HDPE (60) wt.% were incorporated into hydroxyapatite (40) wt.% to form biocomposite using hot-presstechniques. These samples were characterized by XRD, Field Emission scanning electron microscope (FESEM), Atomic forcemicroscopy (AFM), mechanical properties with tensile strength and hardness test. Homogeneous, better distribution of thefibrous network and microstructure arrangements were among the most prominent characteristics obtained through XRD,FESEM, and AFM examinations. The result showed improved approximately (3.1 times) compared with pure sample (withoutaddition MWCNT) in the tensile test. Also, the microhardness improves approximate 24% compared to pure samples HA/HDPE. Based on the experimental results, the synthesis HA/ HDPE/MWCNT bio-composites prepared to have excellentcharacteristics that make them suitable application as a substitute material for bone repair.

Flexural performance of cold-formed square CFST beams strengthened with internal stiffeners

Ahmed W. Al-Zand,W.H. Wan Badaruzzaman,Mustafa M. Ali,Qahtan A. Hasan,Marwan S. Al-Shaikhli 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.1

The tube outward local buckling of Concrete-Filled Steel Tube (CFST) beam under high compression stress is still considered a critical problem, especially for steel tubes with a slender section compared to semi-compact and compact sections. In this study, the flexural performance of stiffened slender cold-formed square tube beams filled with normal concrete was investigated. Fourteen (14) simply supported CFST specimens were tested under static bending loads, stiffened with different shapes and numbers of steel stiffeners that were provided at the inner sides of the tubes. Additional finite element (FE) CFST models were developed to further investigate the influence of using internal stiffeners with varied thickness. The results of tests and FE analyses indicated that the onset of local buckling, that occurs at the top half of the stiffened CFST beam’s cross-section at mid-span was substantially restricted to a smaller region. Generally, it was also observed that, due to increased steel area provided by the stiffeners, the bending capacity, flexural stiffness and energy absorption index of the stiffened beams were significantly improved. The average bending capacity and the initial flexural stiffness of the stiffened specimens for the various shapes, single stiffener situations have increased of about 25% and 39%, respectively. These improvements went up to 45% and 60%, for the double stiffeners situations. Moreover, the bending capacity and the flexural stiffness values obtained from the experimental tests and FE analyses validated well with the values computed from equations of the existing standards.

A mechanical behavior of composite plates using a simple three variable refined plate theory

Ahmed Bakoura,Ibrahim Klouche Djedid,Fouad Bourada,Abdelmoumen Anis Bousahla,S.R. Mahmoud,Abdelouahed Tounsi,Mofareh Hassan Ghazwani,Ali Alnujaie 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.5

A novel three variable refined plate theory (TVRPT) is developed in this article for laminated composite plates for the first time. The theory takes into account the nonlinear variation of transverse shear deformations, and satisfies the boundary conditions of zero traction on the plate surfaces without considering the “shear correction factor”. The important characteristic of this new kinematic is that the unknowns numbers is only 3 as is employed in “classical plate theory” (CPT). The numerical results of the current theory are compared with 3D-elasticity solutions and the calculations of “first order theories” and other higher order models found in the literature.

Effect of moisture absorption on damping and dynamic stiffness of carbon fiber/epoxy composites

Behzad Ahmed Zai,박명균,H. S. Choi,Hassan Mehboob,Rashid Ali 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.11

In this paper, the damping and dynamic stiffness of UHN125C carbon fiber/epoxy composite beam was experimentally measured. The effect of fiber orientation angle and stacking sequences on damping, resonance frequency, and dynamic stiffness was discussed with a focus on the effect of moisture absorption. Dried specimens were immersed in distilled water for a certain period to absorb water for 8, 16, and 24 d, respectively, and the moisture content absorbed in the specimen was measured. Furthermore, using the impact hammer technique, the measurements of dynamic responses were conducted on a cantilever beam specimen with one end clamped by bolts and metal plates. The damping properties in terms of loss factor were approximated by half-power bandwidth technique. The dynamic stiffness was evaluated using resonance frequency as a function of moisture content. The damping increased with the increase of moisture content; however, the dynamic stiffness reduced with the reduction of resonance frequency. The results of the dynamic stiffness were aided by measuring the dynamic strain using DBU-120A strain-indicating software. The increment in the dynamic strain strengthened the results obtained for dynamic stiffness.

Optimal Economic and Environmental Indices for Hybrid PV/ Wind-Based Battery Storage System

Elnozahy Ahmed,Yousef Ali M.,Ghoneim Sherif S. M.,Abdelwahab Saad A. Mohamed,Mohamed Moayed,Abo-Elyousr Farag K. 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.6

This paper shows an application of hybrid PV/wind energy and battery storage in the islanded area. This work’s main target allows the distributed energy resources to contribute effi ciently in the economic feasibility and enhance the environmental impact of the hybrid renewable energy source. Several factors such as levelized cost of energy (COE), greenhouse gas (GHG) emissions, and loss of power supply probability are studied. A combined solution is to compromise the economic and environmental aspects via the Utopia point approach is investigated. The optimal confi guration of the hybrid PV/wind along with battery-storage and diesel engine as secondary source is obtained via meta-heuristic optimizers: Genetic Algorithm (GA) and Particle-Swarm Optimization (PSO) and impartial comparison of the results with HOMER software. The results of Utopia point solution show that the PV (about 46%) and wind turbine (about 13%) are shared signifi cantly as primary renewable sources and battery storage (about 39%) as storage options. Meanwhile, the diesel engine (about 3%) has insignifi cant sharing in feeding the demand load. The optimal COE and GHG, which are achieved via GA and PSO optimization techniques are 0.182$/kWh and 12076 kg/year, agansit 0.343$/kWh and 17618 kg/year that are obtained via HOMER software, respectively. This corssponing to 47% and 31% reduction in COE and GHG, respectively. Sensitivity studies demonstrate that the variation of the wind energy sharing from 50 to 150% shows that the wind energy has a slight eff ect considering the GHG emissions. Contrarily, lower PV sharing ratios undesirably raises the levelized COE, however, reduces the GHG emissions.