Structural, Optical and Room Temperature Magnetic Study of Mn-Doped ZnO Nanoparticles

Majed Sharrouf,Ramadan Awad,Salem Marhaba,Douaa El-Said Bakeer 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.4

Undoped and Mn-doped ZnO nanoparticles (Zn1-xMnxO), with nominal weight percentages (0:00 ≤ x ≤ 0.10), have been synthesized by co-precipitation technique. The synthesized nanoparticles are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR). From XRD analysis, the compound ZnMnO3 is formed for x ≥ 0.05 with cubic structure (a = 8.3694 Å) and its concentration increases with x. Moreover, XRD analysis reveals the wurtzite hexagonal crystal structure for ZnO. The lattice parameters (a and c) of Zn1-xMnxO are calculated and they increase with the doping concentration of Mn as a consequence of the larger ionic size of Mn2+ ions compared to Zn2+ ions. The crystallite size is calculated for all the samples using Debye– Scherrer's method (SSM), Williamson–Hall methods (UDM, USDM and UDEDM) and SizeStrain Plot method (SSP), and the results are in good agreement with TEM. The presence of functional groups and the chemical bonding is confirmed by FTIR spectra that shows a peak shift between undoped and doped ZnO. The energy bandgap (Eg) is calculated for different concentrations of Mn (0.00 ≤ x ≤ 0.10) by using the UV-visible optical spectroscopy, between 300 nm and 800 nm, showing a noticeable drop in Eg with x. At room temperature, the magnetization of the samples reveals the intrinsic ferromagnetic (FM) behavior of undoped ZnO, ferromagnetic behavior of ZnxMn1-xO (0.01 ≤ x ≤ 0.03) and the co-existence of ferromagnetic and paramagnetic behavior for ZnxMn1-xO (0.05 ≤ x ≤ 0.10). This ferromagnetism is decreased for the doped samples as a consequence of antiferromagnetic coupling between Mn ions. The two samples correspond to x = 0.01 and x = 0.10, tend to be superparamagnetic because of the formation of single domain particles as a consequence of small particle size. x = 0.03 shows an optimum value of Mn concentration for maximum saturation magnetization and the best ferromagnetic nature.

Hate Speech Detection Using Modified Principal Component Analysis and Enhanced Convolution Neural Network on Twitter Dataset

Majed, Alowaidi International Journal of Computer ScienceNetwork S 2023 International journal of computer science and netw Vol.23 No.1

Traditionally used for networking computers and communications, the Internet has been evolving from the beginning. Internet is the backbone for many things on the web including social media. The concept of social networking which started in the early 1990s has also been growing with the internet. Social Networking Sites (SNSs) sprung and stayed back to an important element of internet usage mainly due to the services or provisions they allow on the web. Twitter and Facebook have become the primary means by which most individuals keep in touch with others and carry on substantive conversations. These sites allow the posting of photos, videos and support audio and video storage on the sites which can be shared amongst users. Although an attractive option, these provisions have also culminated in issues for these sites like posting offensive material. Though not always, users of SNSs have their share in promoting hate by their words or speeches which is difficult to be curtailed after being uploaded in the media. Hence, this article outlines a process for extracting user reviews from the Twitter corpus in order to identify instances of hate speech. Through the use of MPCA (Modified Principal Component Analysis) and ECNN, we are able to identify instances of hate speech in the text (Enhanced Convolutional Neural Network). With the use of NLP, a fully autonomous system for assessing syntax and meaning can be established (NLP). There is a strong emphasis on pre-processing, feature extraction, and classification. Cleansing the text by removing extra spaces, punctuation, and stop words is what normalization is all about. In the process of extracting features, these features that have already been processed are used. During the feature extraction process, the MPCA algorithm is used. It takes a set of related features and pulls out the ones that tell us the most about the dataset we give itThe proposed categorization method is then put forth as a means of detecting instances of hate speech or abusive language. It is argued that ECNN is superior to other methods for identifying hateful content online. It can take in massive amounts of data and quickly return accurate results, especially for larger datasets. As a result, the proposed MPCA+ECNN algorithm improves not only the F-measure values, but also the accuracy, precision, and recall.

A Laboratory-Based Study for First Documented Case of Urinary Myiasis Caused by Larvae of Megaselia scalaris(Diptera: Phoridae) in Saudi Arabia

Majed H. Wakid 대한기생충학열대의학회 2008 The Korean Journal of Parasitology Vol.46 No.1

Simple Shear Extrusion of Al/Al2O3 Composite Prepared by Stir Casting and Hot Forging

Majed Zabihi,Fathallah Qods,Esmaeil Emadoddin 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.1

In this study, aluminum/alumina composites with 3 and 5 vol% reinforcement particles were manufactured via stir castingand hot forging; they were severely deformed by the simple shear extrusion (SSE) technique. Three SSE dies with differentdistortion angles were utilized in this work. The SSE-ed samples with α = 22.5° were then fractured after one pass, whileSSE-ed samples with α = 8 and 10° were deformed up to thirteen passes, successfully. Microstructural evolution, porositypercentage and micro hardness parameters were investigated after each process. Shear punch test was then used to evaluatethe mechanical properties. Additionally, the applied force and stress/strain distributions were evaluated by the finite elementmethod (FEM) code via ABAQUS® simulation software in different passes. Moreover, the effect of the SSE process on thefracture behavior of the commercial Al and aluminum matrix composite was studied. The results showed that the effectivestrain was increased with increasing the number of SSE passes and distortion angles, while the applied force was decreasedwith increasing the number of passes. Microstructure, bonding quality, hardness and porosity percentage were also improvedby using forging and SSE processes. During the process, ultimate shear strength was enhanced with increasing the amountsof effective strain; also, shear elongation percentage was decreased. Further, SEM observations showed that the fracturemode in the SSE-ed commercial Al sample was a typical ductile one, whereas the fracture mode was nearly shear ductilewith more flat surfaces in the Al-5 vol% Al2O3specimens.

Effect of Intermittent Fasting on Glucose Homeostasis and Bone Remodeling in Glucocorticoid-Induced Osteoporosis Rat Model

Majed G. Alrowaili,Abdelaziz M. Hussein,Elsayed A. Eid,Mohamed S. Serria,Hussein Abdellatif,Hussein F Sakr 대한골대사학회 2021 대한골대사학회지 Vol.28 No.4

Background: The present study examined the effect of intermittent fasting (IF) on bone mineral content (BMC) and bone mineral density (BMD) and the markers of bone remodeling in a glucocorticoid-induced osteoporosis (GIO) rat model. Methods: Forty male rats were allocated to 4 groups (N=10 per group): control group of normal rats; control+IF group (normal rats subjected to IF for 16-18 hr daily for 90 days); dexamethasone (DEX) group: (DEX [0.5 mg i.p.] for 90 days); and DEX+IF group (DEX and IF for 90 days). By the end of the experiment, BMD and BMC in the right tibia were measured. Serum levels of the following were measured: glucose; insulin; triglycerides (TGs); total cholesterol; parathyroid hormone (PTH); osteoprotegerin (OPG); receptor activator of nuclear factor-κB (RANK); bone-resorbing cytokines, including bone deoxypyridinoline (DPD), N-terminal telopeptide of collagen type I (NTX-1), and tartrate-resistant acid phosphatase 5b (TRAP-5b); and bone-forming cytokines, including alkaline phosphatase (ALP) and osteocalcin (OC). Results: DEX administration for 90 days resulted in significantly increased serum levels of glucose, insulin, TGs, cholesterol, PTH, OPG, DPD, NTX-1, and TRAP-5b and significantly decreased BMD, BMC, and serum levels of RANK, OC, and ALP (all P<0.05). IF for 90 days significantly improved all these parameters (all P<0.05). Conclusions: IF corrected GIO in rats by inhibiting osteoclastogenesis and PTH secretion and stimulating osteoblast activity.

Numerical simulation of the temperature rise in intermediate and high strain rate experiments

Majed Baselem,Ramzi Othman,Abdessalem Chamekh 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

Intermediate and high strain rate experiments are of a limited duration. Thus, the specimen temperature cannot be assumed constant. Inthis work, we investigated the adiabatic assumption in intermediate and high strain experiments. A two-step one-dimensional model wasdeveloped to simulate the temperature rise in Hopkinson bar experiments for strain rates ranging between 1 and 5000/s. The model isapplied to predict temperature rise in an aluminum alloy. The adiabatic assumption is shown to be valid for strain rates higher than 500/s. However, the isothermal assumption is not valid even at 1/s of strain rate. These conclusions are very important for the interpretation ofthe stress-strain curves that are measured at medium and high strain rates.

Failure Mechanism of a Granular Bed Induced by a Horizontal Water Jet Using Particle Image Velocimetry

Majed Omar Alsaydalani 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.6

Particle image velocimetry (PIV) was used to investigate the failure mechanism of a granular bed subjected to a water jet emerging laterally from a vertical, impermeable face. Experiments were performed in a modified seepage tank made of plexiglass with dimensions of 700 × 600 × 103 mm. The bed of particles was subjected to a lateral seepage flow at a controlled rate, and the motion of the particles was recorded using a digital camera. Measurements of flow and pore pressure were also made. Several stages of failure were observed during the repeated experiments: 1) outwards movement of the particles (horizontally and vertically upwards), 2) cavity formation, 3) cavity enlargement, and 4) the emergence of a fluidised zone at the bed surface. Trends relating to the flow rate of fluid flow to the onset of failure were also noted. The PIV analyses revealed the movement of sand grains and boundaries between regions in which sand grains either did or did not move. An analytical model based on the Ergun equation is presented to predict the onset of failure. This study provides valuable insights into the failure mechanism of granular materials triggered by lateral seepage flow.

Impact Force Localization and Identification in Structure by Using Optimizer Based on Random Search

Majed M. Al-Haidari,Junhong Park 한국소음진동공학회 2018 한국소음진동공학회 학술대회논문집 Vol.2018 No.10

Detection and Phylogenetic Analysis of Viruses Linked with Fig Mosaic Disease in Seventeen Fig Cultivars in Palestine

Rana Majed Jamous,Salam Yousef Abu Zaitoun,Omar Bassam Mallah,Munqez Shtaya,Toufic Elbeaino,Mohammed Saleem Ali-Shtayeh 한국식물병리학회 2020 Plant Pathology Journal Vol.36 No.3

Fig mosaic is a viral disease (FMD) that spreads in Palestinian common fig (Ficus carica L.) orchards. Recognizing the economic value of fig plants and the harmful nature of FMD, the disease poses a significant threat to the economy of the fig production in Palestine. We applied the reverse transcription and amplification (RT-PCR) and PCR technique to leaf samples of 77 trees and 14 seedlings of 17 fig cultivars. The samples were collected from orchards in the main fig-growing provinces of the Palestinian West Bank, to assess the prevalence of viruses associated with FMD, and con- firm a possible link of symptoms with viruses detected. Four viruses were detected: Fig mosaic virus (FMV), Fig badnavirus-1 (FBV-1), Fig leaf mottle-associated virus 2 (FLMaV-2), and Fig fleck-associated virus (FFkaV). FMV and FBV-1 were found in all tested fig plants (100%), while FLMaV-2 and FFkaV were detected in 61.5% and 33% of the fig samples, respectively. The high incidence of FBV-1 in the newly propagated symptomatic and symptomless seedlings from differ- ent cultivars may be an indication that FBV-1 is integrated into the genome of the fig in a cultivar nondiscriminatory manner. Very weak or no association was detected between FMD symptoms severity in the 17 Palestinian fig cultivars with the various viruses’ combinations observed (i.e., number of the viruses infecting the plant). These results support the notion that FMD symptom severity expression is likely to be controlled by a combination of FMV infection, cultivars, and environmental factors, rather than the number of viruses infecting the plant.

Biological and Molecular Characterization of Tomato brown rugose fruit virus (ToBRFV) on Tomato Plants in the State of Palestine

Rana Majed Jamous,Salam Yousef Abu Zaitoun,Omar Bassam Mallah,Mohammed Saleem Ali-Shtayeh 한국식물병리학회 2022 식물병연구 Vol.28 No.2

The incidence of Tomato brown rugose fruit virus (ToBRFV) and biological and molecular characterization of the Palestinian isolates of ToBRFV are described in this study. Symptomatic leaf samples obtained from Solanum lycopersicum L. (tomatoes) and Nicotiana tabacum L. (cultivated tobacco) plants were tested for tobamoviruses infection by reverse transcription polymerase chain reaction. Tomato leaf samples collected from Tulkarm and Qalqilia are infected with ToBRFV-PAL with an infection rate of 76% and 72.5%, respectively. Leaf samples collected from Jenin and Nablus were found to be mixed infected with ToBRFV-PAL and Tobacco mosaic virus (TMV) (100%). Sequence analysis of the ToBRFV-PAL genome showed that the net average nucleotide divergence between ToBRFV/F48-PAL strain and the Israeli and Turkish strains was 0.0026398±0.0006638 (±standard error of mean), while it was 0.0033066±0.0007433 between ToBRFV/F42-PAL and these two isolates. In the phylogenetic tree constructed with the complete genomic sequence, all the ToBRFV isolates were clustered together and formed a sister branch with the TMV. The sequenced Palestinian isolates of ToBRFV-PAL shared the highest nucleotide identity with the Israeli ToBRFV isolate suggesting that the virus was introduced to Palestine from Israel. The findings of this study enhance our understanding of the biological and molecular characteristics of ToBRFV which would help in the management of the disease.