Sadeq Hani Lafta
@uotechnology.edu.iq
Applied Science Dep
University of Technology
RESEARCH INTERESTS
Nano Magnetic Materials
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ekhlas Abbas Albahrani, Tayseer Karam Alshekly, and Sadeq H. Lafta
Springer Science and Business Media LLC
Dalal Maseer Naser, Sadiq H. Lafta, and Mustafa Shakir Hashim
Wiley
AbstractThree samples of Fe−S were prepared with different hydrothermal periods (6, 12, and 18 h). X‐ray diffraction (XRD) test showed that the first produced sample contained 42.3 wt % of magnetite, 35 wt % of greigite, and 22.7 wt % of pyrite phases. The same phases were formed during the second period but with different wt % ratios. The greigite increased to 67.8 wt % by the third period, while the magnetite and pyrite phases vanished and were associated with a low ratio of the presence of pyrrhotite and FeO2. Scanning electron microscope (SEM) images confirmed the formation of the nanoparticles. The increase in the hydrothermal time produced a reduction in the saturation magnetization (39.8 to 9.1) emu/g and the remanence magnetization (8 to 2.4) emu/g, and increasing in the coercivity. To assess the viability of Michigan Cancer Foundation‐7 (MCF‐7) and hemolytic disease of the fetus and newborn (HdFn) cells, a colorimetric assay for assessing cell metabolic activity (MTT) was applied to the third sample. The outcome verified iron sulfide‘s cytocompatibility against HdFn cells even at high concentrations and good anticancer activity against MCF‐7 cell lines. The result of the DPPH test confirmed that the third sample had antioxidant activity equivalent to that of ascorbic acid.
Mohammed M. Al-Mhadawi, Ekhlas Abbas Albahrani, and Sadeq H. Lafta
Elsevier BV
Sadeq H. Lafta
National Academy of Sciences of Ukraine (Co. LTD Ukrinformnauka) (Publications)
Spinel ferrite nanoparticles of Co0.2Ni0.8Fe2O4 composition are utilized as filler magnetic particles in the carrier fluid of sesame oil to prepare a magnetorheological fluid. The hydrothermal method is adopted to prepare CoNi ferrite nanoparticles. X-ray diffraction analysis is used to check the crystalline phase, and transmission electron microscopy is used to image the particles to find the size and shape of particles. The average size is about 18 nm. The magnetic properties are determined by measuring the hysteresis loop by the superconducting quantum interference device technique. The saturation magnetization is 59.4 emu/g, and the coercivity is 30 Oe. The Langevin fitting is applied to the hysteresis loop to show that the particle moment is about 16 × 103 μB. The viscosity and shear stress are measured against the shear rate, where the latter parameters are extracted from the viscosity and the viscometer spindle speed. The viscosity behavior showed the shear thinning against the shear rate. The viscosity increases with the magnetic field. The shear stress increases with the shear rate and has a very good matching with the Bingham model, rather than with the Herschel–Bulkley model, while describing the measured data. We observed a clear high static shear stress at low shear rates that are growing with the magnetic field. The yield stress was increased linearly with magnetic field strength.
Kadhim R. Gbashi, Ali Bahari, and Sadeq H. Lafta
Springer Science and Business Media LLC
Luma H. Abdel-Mohsen, , Sadeq H. Lafta, Mustafah Sh. Hashim, , and
Elsevier BV
Four compositions of spinel NixBa1-xFe2O4 of x =0, 0.05, 0.01, and 0.15 were prepared by the auto-combustion route. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) analyses were utilized to determine the structural properties. All samples showed a cubic spinel structure with a noticeable FTIR tetrahedral band blue shift as the molar ratio x was increased. The crystallite size and particle size have the same behavior as x changed from 0 to 0.15. Spherical nanoparticles aggregated into large clusters were found throughout the samples. Magnetic properties, displayed a drop in magnetization saturation as x increased to its max value. A saturation magnetization (Ms) of more than 48 emu/g was achieved at x = 0 and x = 0.15 while the coercivity did not change clearly. The fitting by the Langevin equation using Originlab software showed very close values of Ms to those measured by the vibrating sample magnetometer (VSM) test. Magnetic parameters are generally affected by both composition and particle size.
Ekhlas Abbas Albahrani, Sadeq H. Lafta, and Naeem Howrie Ghayad
River Publishers
This paper introduces a new Database Transposition, Substitution and XORing Algorithm (DTSXA) based on using chaotic maps. It is based primarily on two well-known security properties: confusion and diffusion. A random number generator was depended on to produce the keys for the algorithm of encryption and decryption. The encryption of the Arabic language in addition to the English language was done, besides it can encrypt a table, individual row and individual column. The suggested algorithm was obeyed and analyzed by different tests involving brute force attack analyses, statistical attack analyses (security analysis histogram, correlation coefficient analysis and information entropy analysis), key sensitivity analysis, differential attack analysis, and mean square error analysis. This algorithm passed all the applied analyses well-deservedly, which indicates that the presented encryption algorithm has a high security level due to its large key space and high sensitivity to the change in the cipher keys.
SADEQ H. LAFTA
World Scientific Pub Co Pte Ltd
Investigation of the role of hydrothermal temperature on hematite nanoparticles structural, magnetic, and ferromagnetic resonance (FMR) properties was done. Ferric chloride and sodium hydroxide were used as the starting precursors. The hydrothermal temperature was varied in the range of 140–200∘C by a step of 20∘C. XRD, SEM, VSM, and FMR analyses were used to check the particles’ properties. The prevailing strongly phase was hematite with some small peaks related to other phases. A reduction in lattice constant and increase in the crystallite size to more than 27[Formula: see text]nm is observed. The particles’ morphology exhibited polygon particles down to spherical particles as the average particle size gets larger up to 45[Formula: see text]nm. The hysteresis loops showed unsaturated curves with rising coercivity up to 150Oe. The antiferromagnetism permeability, magnetization saturation, and dipole moment were found by Langevin fitting to the experimental hysteresis loops, where all of them have the same behavior represented by an initial drop followed by increase in their values. The FMR spectra are characterized by low intensities and low linewidths accompanied by very low blue shift in the resonance field. All samples showed Lorentzian distribution as checked by the Lorentz function. Landé [Formula: see text]-factor has values very close but less than 2 due to the effect of crystal field and particle magnetic moment variations.
Kadhim R. Gbashi, Sadeq H. Lafta, and Natheer B. Mahmood
Elsevier BV
Tayseer Karam Alshekly, Ekhlas Abbas Albahrani, and Sadeq H. Lafta
Springer Science and Business Media LLC
L H Abdel-Mohsen, S H Lafta, and M Sh Hashim
IOP Publishing
Abstract A comparison between using NaOH and NH4OH for synthesizing nano Ni0.1Ba0.9Fe2O4 via autocombustion method was done. During the preparation of the two samples, metal salts were dissolved in distilled water and then the two chemical bases were added separately till pH reaches 7.5. The samples were fired at 600°C for 2h. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron microscope (SEM), and vibrating sample magnetometer (VSM) tests were utilized to characterize the samples. XRD test showed a spinel cubic pattern for the two samples and their lattice constants were comparable to that in literature. The calculated crystallite sizes for the two samples were so approximated. SEM images showed a greater average spherical particle size for the prepared sample by NH4OH. FTIR analysis illustrated some reaction residuals in the samples prepared by NaOH. The sample prepared by NH4OH showed higher magnetization saturation and low coercivity. Depending on particle size and squarness ratio, the sample prepared by NaOH is more super paramagnetic compared to the other.
Ekhlas Abbas Albahrani, Tayseer Karam Alshekly, and Sadeq H. Lafta
River Publishers
Due to the quick improvement in digital communications and multimedia applications during recent periods up to the current time, data protection of digital data such as image, audio and video becomes a significant challenge. The security of audio data that transfer through different networks was rated as a preferred research field in the preceding years. This review covers the recent contribution for audio encryption and gives the most evaluations for audio encryption algorithm involving security analysis, computational complexity and quality analysis and their requirements. This paper fundamentally concentrates on displaying the different types of audio encryption and decryption techniques based on chaotic maps. Digital and analog audio algorithms were displayed, discussed and compared with the illustration of the important features and drawbacks. Various digital and audio proposed projects for audio encryption using chaotic maps have been covered, which they showed extreme sensitivity to initial conditions, unpredictability and conducting in a quasi-random manner. A comparison among the proposed algorithms in the key space, chaotic maps sensitivity and statistical analysis were provided.
Sawsen Abdulhadi Mahmood, Azal Monshed Abid, and Sadeq H. Lafta
Institute of Advanced Engineering and Science
The automatic detection of anomaly events in video sequence has become a critical issue and essential demand for the extensive deployment of computer vision systems such as video surveillance applications. An anomaly event in video can be denoted as outlier behavior within video frames which formulated by a deviation from the stable scene. In this paper, an anomaly event detection and localization method in video sequence is presented including multilevel strategy as temporal frames differences estimation, modelling of normal and abnormal behavior using regression model and finally density–based clustering to detect the outliers (abnormal event) at clips level. Hence, outlier score is obtained at the segment or clip level along video frames sequences. The proposed method seplits video frames into nonoverlapped clips using global outlier detection process. Afterward, at each clip, the local outliers are determined based on density of each clip. Extensive experiments were conducted upon two public video datasets which include dense and scattered outliers along video sequence. The experiments were performed on two common public datasets (Avenue) and University of California, San Diego (UCSD). The experimental results exhibited that the proposed method detects well outlier frames at clip level with lower computational complexity comparing to the state-of-the-art methods.
Sarmad A. Ibrahim, Sadeq H. Lafta, and Wafaa A. Hussain
Walter de Gruyter GmbH
Abstract Stainless steel 316L (SS316L) as a significant bio-material, their wires were used to support the PMMA matrix. Two simple and low-cost surface pretreatments for SS316L wires were performed to enhance denture impact strength: mechanical scratching (treating SS316L wires with SiC powder inside a rotating container) and electrochemical anodizing. Three mechanical scratching samples for different periods of 60, 90 and 120min were prepared. Anodizing technique conditions were: Ethylene glycol with perchloric acid as an anodizing solution, 15V supplying and graphite rod as an anode. Anodizing process involved three pretreating periods of 15, 20, and 30min. All the prepared samples had dimensions of 65 × 10 × 3 mm. SEM technique showed different morphology nature involved holes, scratches and pores with a density of 104/μm2 and a crack length of 60μm. The PMMA reinforced with scratched stainless steel 316L wire surface for 120 min presented the highest impact strength value (42 kJ/m2) with (450.91%) increment. Anodizing samples showed a fluctuating behavior of samples with enhancing in the impact strength of anodizing wire for 20min of about 26.99 kJ/m2, which is still lower than that for scratched samples in average.
Sadeq H. Lafta
Springer Science and Business Media LLC
Nanoparticles of hematite were prepared by the precipitation method. Structural, hysteresis, moment-temperature, ferromagnetic resonance tests were performed. All hematite peaks were appeared in the XRD pattern with corundum phase of crystallite size of 15 nm. The SEM images showed that the average particle size is around 21 nm with ribbed shape. Different Fe–O bond peaks were registered in the FTIR test. The sample showed weak ferromagnetic state as was checked by M-H and M-T tests. The M-H test showed opened loop at low-field region and linear behavior at high-field region with susceptibilities of 1.4 × 10−5 emu/g Oe and 7.5 × 10−6 emu/g Oe respectively. Fitting by Langevin equation is conducted to find the particle moment. Morin temperature was found to be 17.77 K, while Neel temperature was about 614 K. A comparison with literature was given. FMR test showed a shift in the resonance field with broadened line having Lande g factor of 1.90498 at 9.3 GHz.
Ekhlas Abbas Albahrani, Amal Abdulbaqi Maryoosh, and Sadeq H. Lafta
Elsevier BV
Abstract A new image encryption was done through using chaotic theory in the diffusion and confusion processes. Diffusion process was performed by using the chaotic cross map to permutate the matrix of each image color channel. Confusion process was implemented by a modified Playfair algorithm to generalize the classical one. Playfair algorithm divides the original text of characters into blocks, where each block usually contains two-character. The main limitations of Playfair cipher are that: it encrypts only 25 characters and one cannot use special characters and numbers. In addition, keyword can only take 25 letters alone without duplicates. The new method uses two cross chaotic maps to generate 16×16 playfair matrix as a key. The image is partitioned into a definite number of blocks such that each block has 16×16 bytes. Then, each block will be encrypted by different playfair matrix. All input data such as capital letter, small letter, digits and special characters, etc. can be encrypted by this new method. Experimental results showed that the proposed playfair cipher is more secure than the classical one and very sensitive to a slight change in the secret keys. The actual results of the encryption process showed that the proposed algorithm can defend against different attacks.
SADEQ H. LAFTA, ALI ABDULRAHMAN TAHA, MUHAMMAD M. FARHAN, and SHAIMA Y. ABDULFATTAH
World Scientific Pub Co Pte Lt
Nanoparticles of alpha ferric oxide ([Formula: see text]-Fe2O3) were prepared by the hydrothermal method. Structural properties of [Formula: see text]-Fe2O3 were determined by XRD, SEM and AFM measurements. The particles had a good matching with standard pattern. Average particle size was about 90[Formula: see text]nm and the distribution extended from about 20[Formula: see text]nm to 120[Formula: see text]nm. Biocompatibility study of ferric oxide nanoparticles against bacteria, parasites, tumor cell line and normal cells was determined. No antibacterial activity was observed for the concentration, of ferric oxide nanoparticles in distilled water, up to 1.5[Formula: see text]mg/ml vs. E. coli and S. aureus. Moreover, MTT assay was used to determine the cytotoxicity against parasites and cells. Intermediate cytotoxicity (53.30%) of 1.5[Formula: see text]mg/ml of prepared nanoparticles was noted against L. tropica, while weak cytotoxicity of 5.20% was observed against L. donovani at the same concentration of ferric oxide nanoparticles. On the other hand, the prepared nanoparticles revealed low cytotoxicity (47.28%) against SR tumor cell line, while no cytotoxicity was shown against lymphocytes, as a model of normal cells.
Sadeq H. Lafta
Institute of Electrical and Electronics Engineers (IEEE)
Superparamagnetic particles of Ni ferrite prepared by co-precipitation technique were mixed with epoxy and studied by broadband ferromagnetic resonance (BFMR) in the range 2–26 GHz. The XRD and TEM showed that particles had a spinel structure and a small size around 27 nm. The particles exhibited a hysteresis loop with superparamagnetic behavior and the moment-temperature analyses showed a blocking temperature higher than room temperature. SC-BFMR analysis was based on measuring the diode voltage ratio when the sample is over the SC to the diode voltage when the sample is absent. The BFMR spectrums of Ni ferrite-epoxy composites were more refined at low fields than the higher one, when different phenomena were interfered. Below 5000 G, the resonant frequency-field relation was linear for all samples. The effective g-factor and effective magnetization calculated from resonant frequency field were generally decreased as Ni2+ was increased. The losses were represented as the inverse of the quality factor which was increased with Ni2+ content and was dropped as frequency was growing.
Emad K. Al-Shakarchi, Sadeq H. Lafta, Ali Musa, M. Farle, and R. Salikhov
Springer Science and Business Media LLC
Magnetic hysteresis loop and ferromagnetic resonance (FMR) behaviour had been studied by considering the variation of the molar ratio of Li0.5−0.5xNixFe2.5−0.5xO4 ferrite nanostructure prepared by the hydrothermal method. The parameters of the ferrite nanostructure include coercivity (Hc), saturation magnetisation (Ms) and magnetic susceptibility. There was low coercivity at x = 0.3, high saturation magnetisation and high susceptibility (χi) at (x = 0.5). These parameters showed an improvement in their values compared with the samples prepared by conventional methods. The FMR analysis indicated that these samples were lossy materials due to having a broad line width ranging from 800 to 925 G. The FMR lines had asymmetric shapes due to anisotropic broadening and conduction mechanism.
Sadeq H. Lafta
The Korean Magnetics Society
The ferromagnetic resonance and other magnetic properties dependence on Ni/Fe ratio and crystallite size were investigated for nano nickel ferrite (NiFe2O4). The crystallite size was controlled by controlling the nickel content in the starting material solution. The XRD and TEM were utilized to measure the crystallite size through Scherrer formula and particle size respectively. The most frequent particle sizes were lower than crystallite size, which ranged from 16.5 to 44.65 nm. The general behavior of M-H loop shapes and parameters showed superparamagnetic one. The saturation magnetization had a maximum value at Ni/Fe molar ratio equal to 0.186. The FMR signals showed, generally, broad linewidths, where the maximum width and minimum resonance field were for the sample of the lowest crystalline size. Furthermore, FMR resonance field shows linear dependence on crystalline size. The fitting relation was estimated to express this linear dependency on the base of behavior coincidence between particle size and the inverse of saturation magnetization. The given interpretations to understand the intercept and the slope meanings of the fitted relation were based on Larmor equation, and inhomogeneous in the anisotropy constant.
Sadeq H. Lafta
Walter de Gruyter GmbH
AbstractNano nickel ferrite particles were prepared at pH values 1.5, 4, 7, 10, 13 by a hydrothermal method using metal chlorides and NaOH as an oxidant and solution basicity controller. There is a phase transition from hematite to spinel ferrite that begins when the pH reaches 4. The lowest crystallite size (4 nm) was associated with a highest lattice constant (8.345 Å), at pH=4. Whereas maximum crystallite size 64.5 nm corresponds lattice constant of 8.298 Å at pH=10. The highest magnetization (48 emu/g) value was achieved for the sample prepared at pH=7, which at the same time has a lower coercivity. The samples synthesized at pH ≥4 show superparamagnetic behavior owing to its low particle size and to zero field cooling and field cooling measurements. The ferromagnetic resonance (FMR) cavity tests analysis show that the broadened linewidth (770 Oe) and high imaginary permeability or high microwave absorption which is linked to high magnetization and low coercivity of superparamagnetic particles and their aggregation. There was a shift in the resonance field due to internal fields and cation distribution.
Emad K. Al-Shakarchi, Sadeq H. Lafta, Ali M. Musa, M. Farle, and R. Salikov
Springer Science and Business Media LLC
Li-Ni ferrite with chemical formula Li0.5−0.5xNixFe2.5−0.5xO4 was prepared by hydrothermal method with different Ni contents (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) using metal chlorides, ferrous sulfate and sodium hydroxide as oxidants. The hydrothermal treatment was accomplished at (155 ∘ C) for (3 h). The required analyses of XRD, FTIR, SEM, TEM, EDX and magnetic hysteresis loop were performed to characterize the complete behavior as a function of x. It was found that lattice constant has a small increase as x increased. Crystallite size had a minimum value of about 13 nm at x = 1.0 and maximum value of about 33 nm at x = 0.3. It was also found that XRD density increased as x was increased. The particle size distributions showed that the maximum value is around 22 nm. FTIR analysis showed the presence of two main peaks with some shifting. Nanospheres were the predominant particles beside the presence of low nanorod concentration. M-H loops had super paramagnetic shape. The coercivity had a minimum value at x = 0.5. The magnetic saturation had a maximum value at x = 0.3, and the initial susceptibility χi had a maximum value at x = 0.5.