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Biomass Based Bioenergy: Technologies and Impact on Environmental Sustainability
Ikram Mehrez,Sutha Shobana,Georgeio Semaan,김상현,Gopalakrishnan Kumar 대한환경공학회 2022 대한환경공학회지 Vol.44 No.1
Biomass based bioenergy has many advantages evidently as their available quantity and renewability, when compared to the petro-derived traditional fossil fuels. Thereby, such bioenergy occupies a vital role defensively to the global energy requirement as well as guarantee energy supply. On the other hand, it should be considered that the development of biomass based energy may lead to some serious environmental issues and those are only based on the published data. Such adverse environmental alterations, mainly erosion of soil organic carbon, greenhouse gas emissions, lessening of water quantity and quality, have mainly been based on type of biomass source utilized, location of the land, and management practices. Consequently, more attention should be paid towards environmental protection, while implementing the production of biomass based bioenergy. In this study, various types of biomass, its conversion technology, advantages and disadvantages and its environmental issues of bioenergy production in terms of adverse impact on water, air and soil along with protection measures have been discussed.
Ikram Adeel,정현 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.3
A numerical model of the metal transfer process was developed using the thermomagnetohydrodynamic equations and the phase-field method to investigate the influence of pulse frequency on the metal transfer mode, dynamics, and thermal behavior in the pulsed wire-arc additive manufacturing (WAAM) process. The control of droplet transfer mode, dynamics, and thermal behavior is essential in WAAM; otherwise, several potential defects such as high residual stresses and distortion, poor dimensional accuracy, and surface quality may occur due to uneven heat input condition and process instability. Therefore, in this study, eight sets of pulse frequencies ranging from 50 to 225 Hz, in steps of 25 Hz, using identical power source parameters, such as pulse duty cycle and average current of 25.4% and 152 A, respectively, were considered and compared for a nearly square current waveform. The results reveal that only the current pulses with a medium frequency regime (100–175 Hz) achieve the one-droplet-per-pulse mode of metal transfer. Moreover, an increase in pulse frequency leads to a shorter necking length of the pendent droplet and a significantly lower average speed and temperature of the detached droplet. The results for the heat flux analysis indicate that Joule heating and arc heating decrease due to the increase in pulse frequency, whereas the sheath heating remains almost constant using different pulse frequencies. The proposed numerical scheme provides a detailed understanding of controlling and tailoring the different metal transfer modes and their metal transfer stability during WAAM, which benefits further process optimization and control.
Ikram Kheira Bot,Abdelmoumen Anis Bousahla,Amine Zemri,Mohamed Sekkal,Abdelhakim Kaci,Fouad Bourada,Abdelouahed Tounsi,M.H. Ghazwani,S. R. Mahmoud 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.6
This research is devoted to study the effects of humidity and temperature on the bending behavior of functionally graded (FG) ceramic-metal porous plates resting on Pasternak elastic foundation using a quasi-3D hyperbolic shear deformation theory developed recently. The present plate theory with only four unknowns, takes into account both transverse shear and normal deformations and satisfies the zero traction boundary conditions on the surfaces of the functionally graded plate without using shear correction factors. Material properties of porous FG plate are defined by rule of the mixture with an additional term of porosity in the through-thickness direction. The governing differential equations are obtained using the "principle of virtual work". Analytically, the Navier method is used to solve the equations that govern a simply supported FG porous plate. The obtained results are checked by comparing the results determined for the perfect and imperfect FG plates with those available in the scientific literature. Effects due to material index, porosity factors, moisture and thermal loads, foundation rigidities, geometric ratios on the FG porous plate are all examined. Finally, this research will help us to design advanced functionally graded materials to ensure better durability and efficiency for hygro-thermal environments.
Ikrame Zeouk,Khadija Bekhti 경희대학교 융합한의과학연구소 2020 Oriental Pharmacy and Experimental Medicine Vol.20 No.1
Rhamnus alaternus is perennial dioecious shrub growing in the Mediterranean area. It is demonstrated as an important ecological adapted species endowed with a great genetic diversity. R. alaternus is known as a popular medicinal plant widely reported in literature to have an excellent antioxidant potential in addition to various biological properties such as anti mutagenic, antigenotoxic, antihyperlipidemic and antimicrobial activities due to its richness in phytochemicals compounds belonging to different families like anthraquinones, flavonoids and anthocyanins. The present review highlights information collected from all the most published investigations about the ecology, pharmacology, cytotoxicity and phytochemistry of R. alaternus. This work will help to develop new drugs from this species and to direct further scientific researches.
Ikram Adeel,Raza Ahmad,정현 대한용접접합학회 2020 대한용접·접합학회지 Vol.38 No.3
This study was performed to investigate the AC-GMAW process for joining of 6 mm to 8 mm thick AH36 steel plates in a single pass welding using a square groove butt joint configuration. A broad range of experiments was conducted at different welding speeds and joint gaps. Initially, a suitable setting of welding speed and the joint gap was determined based on the results of penetration depth and the gap bridging ability of the welded joints. Then, the quality of the selected welded joints was examined by hardness and tensile testing. Microstructure and fractured sur�face analysis were carried out using scanning electron microscopy (SEM) to examine the surface morphology. Based on the experimental findings, recommendations were made for selecting suitable input welding parameters for the welding of plates up to 8 mm using the AC-GMAW process.
The electrical characterizations and illumination response of Co/N-type GaP junction device
Ikram Orak,Kadir Ejderha,Abdulmecit Turut 한국물리학회 2015 Current Applied Physics Vol.15 No.9
The manuscript describes characterization of a Co/n-GaP junction device. The currentevoltage etemperature (I-V-T), capacitanceefrequencyetemperature (C-f-T) measurements of the device were analyzed in the temperature range of 60e320 K by the steps of 20 K under dark condition, and light condition at room temperature. The characteristic parameters such as barrier height (BH), ideality factor (n) have been determined from the forward bias IeV characteristics on the basis of standard thermionic emission. The BH and n were found to be 0.98 eV and 1.05 at room temperature, respectively. The ideality factor increased and BH decreased with a decrease in temperature. The BH and n were found to be linear dependent on each other at two different regions, and these values are predicted with existence of Gaussian distribution (GD). For the two different methods the BH is seen in good agreement with each other. Especially, the homogeneous BH for the first region is found to around 1.02 eV. The homogeneous BH values are found to be good agreement for 3 different methods such as the linear correlations of BH versus n plot, GD of BHs and Norde's function. Interface states (Nss) and their time constant (t) were calculated from the C-f-T measurements and as sample temperature was increased, the Nss value increased and t decreased in dark conditions. Photovoltaic parameters such as fill factor (FF), power conversion efficiency (ηp), open circuit voltage (Voc) and short circuit current (Isc) were calculated. According to these, it was been seen that the semiconductor device under light illumination showed photovoltaic behavior.