ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY
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373 research outputs found
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Size Reduction and Harmonics Suppression in Microwave Power Dividers: A Comprehensive Review
Full text linkIn this paper, several types of microstrip power divider are studied and compared in terms of harmonics suppression and size reductions. The importance of this research lies in the fact that power dividers are critical components in various communication systems, and their performance directly affects the overall system efficiency. The conventional structure of the power divider has an acceptable performance at operating frequency in terms of excellent output ports isolation, low insertion loss, and high return loss, but occupies large size and passes unwanted signals at higher frequencies along with desired signal without any suppression. Harmonics are popular distortion and has different distortion impacts in many different facilities. Recently, several techniques are introduced to overcome these drawbacks. Applied open stubs, applied resonators, lumped reactive components such as capacitors and inductors, coupled lines, defected ground structure (DGS), and electronic band gaps are common methods, which are widely used to overcome these drawbacks. Finally, the study results show that the resonator-based power dividers and coupled-line-based power dividers have good performances in terms of size reduction and harmonic suppression but increase insertion loss parameter. Furthermore, the lumped reactive component-based power dividers and applied DGS and electromagnetic bandgap cells suppress unwanted harmonics, but they need extra process to fabrication, which is undesirable. Moreover, the open-stub-based power dividers have moderate performance with simple structure, but size reduction and harmonics suppression are not so superior in this method
Cytostatic Effects of Avocado Oil Using Single-cell Gel Electrophoresis (Comet Assay): An Evaluation
Full text linkThe goal of this paper is to assess the mutagenicand genotoxic potentials of avocado oil made from the fruit pulp of Persea Americana, a member of the Lauraceae family.Michigan Cancer Foundation-7 (MCF-7) cells are used in the 3-4,5 dimethylthiazol-2yl-2,5-diphenyl tetrazolium bromide (MTT) test to examine the possible antiproliferative and cytostatic qualities of different doses of avocado oil, and MCF-7 cells are used in the comet assay to examine the potential cytostatic effects of avocado oil extracted from the avocado fruit. DNA in human breast cancer cells is partially damaged by avocado oil. However, DNA damage at low, medium, and high levels was discovered in the positive control. Without positive control, the DNA damage level falls in the low, middle, and high ranges. The MTT assay shows that avocado oil exerts a dose-dependent cytostatic impact on human breast cancer MCF-7 cells with an IC50 value of 379.2 μg/mL, which is the IC50 value that causes genotoxicity in the comet assay
A Comprehensive Review on Microstrip Couplers: Structure, Design Method and Performance
Full text linkIn this work, several types of microstrip couplers are investigated in terms of structure, performance and design methods. These planar 4-ports passive devices transmit a signal through two different channels. Designers' competition has always been in miniaturizing and improving performance of couplers. Some couplers have been offered with a novel structure, which is a special feature. A high-performance coupler should have high isolation and low losses at both channels. The channels are usually overlapped so that the common port return loss in these channels should be low. Among the couplers, those with balanced amplitude and phase are more popular. The popular mathematical analysis methods are even/odd mode analysis, extracting the information from the ABCD matrix and analyzing the equivalent LC circuit of a simple resonator. According to the phase shift value, couplers are classified as 90º and correct multiples of 90º, where a microstrip 0º coupler can be used as a power divider. Some couplers have filtering and harmonic elimination features that are superior to other couplers. However, few designers paid attention to suppressing the harmonics. If the operating frequency is set in according to the type of application, the coupler becomes particularly valuable.ABCD Matri
Magnetic and Electrical Properties of Electrodeposited Nickel Films
Full text linkMagnetic and electrical properties of nickel (Ni) thin films produced by the electrodeposition technique under a range of growth times (30, 40, and 60 s) are investigated thoroughly using Magneto-Optical Kerr Effect (MOKE) magnetometry and Magneto-Resistance setup, respectively. To deeply understand these properties, the elemental composition, surface morphology, and bulk crystalline structure are analyzed using energy dispersive X-ray spectroscopy (EDS) with high-resolution scanning electronmicroscopy (HRSEM), grazing incidence X-ra y reflectivity(GIXR), and X-ray diffraction measurements, respectively. EDSanalysis confirms that these samples are free from impurities andcontamination. An increase in coercive fields (~67 Oe) with widedistribution (58–85 Oe) across the film area and a slight variationin the shape of the loops are noticed by decreasing the film growthtime (30 s). This is attributed to the deviations in the film surfacemorphology (defects), as confirmed by HRSEM and GIXRmeasurements. The angular dependence of the coercivity is nearlyconstant for each sample and most angles, indicating the similarityin the reversal behavior in such films.The sample resistance is foundto be ~20.3 Ω and ~2.8 Ω for films with growth times of 40 s and 60 s,respectively. The co ercivity of the AMR profiles and MOKE loops isconsistent with each other, indicating that the magnetization at thesurface performs similarly to that of their bulks. This article givesan indication that Ni films produced by this technique under suchconditions are soft at longer deposition times and largely isotropic,which is more preferable in some magnetic applications
Radiation Detection and Heavy Metals Measurements in Powdered Blood Sample of Leukemia Patients
Full text linkThis research examines the measurements of radiation detection and heavy metals in blood samples of leukemia and health groups using CR-39 nuclear track detectors and X-ray fluorescence. The results show that the minimum and maximum values of uranium contents found in leukemia blood samples of male (18 years) and female (55 years) patients, respectively. The concentration of heavy metals (Pb, Cd, and Ni) and radium contents is higher in leukemia blood samples, as compared with their concentration in healthy blood samples
Natural Dye of Beetroot: An Agent for Spectrophotometric Determination of Atenolol in the Pharmaceutical Formulations
Full text linkIn this study, a simple and indirect spectrophotometric method for the quantification of atenolol in pharmaceutical formulations, utilizing a natural food dye extracted from red beet root, is presented. The process involves the oxidation of atenolol in a 1 mol/LHCl acidic medium, using an excess of potassium persulfate. Subsequently, the resulting tablet solution is employed to fade the red beetroot dye, and the solution is measured spectrophotometrically. The optimized reaction conditions consist of a 16 µg/mL atenolol solution, 2.1 mL (100 µg/mL) of potassium persulfate, and 5 mL (100 µg/mL) of red beetroot dye. Spectrophotometric measurements were performed at 535 nm, and the linear range for quantification was found to be 4–22 µg/mL (R2 = 0.9987). The method exhibited a limit of detection of 0.01 µg/mL. Notably, the proposed method was successfully applied to analyze various commercial brands of pharmaceutical formulations; yielding results consistent with those obtained using the pharmacopeia method. This research offers a valuable and accessible technique for atenolol quantification, demonstrating potential significance in pharmaceutical analysis and quality control processes
Drilling Pipe Corrosion Reduction Using Natural, Biodegradable, and Environmentally Friendly Additive to the Drilling Fluid
Full text linkCorrosion is one of the disasters attacking the drilling tools, particularly the drill pipes. Drilling fluid is the corrosive that increase the rate of corrosion in the pipes. In this study, it is intended to reduce the corrosivity of drilling fluid using a Prosopis farcta powder material. A natural, biodegradable, and environmentally friendly additive is added to the fluid in different particle sizes and amounts to obtain the lowest corrosion rate. Experiments are conducted in a well-like environment (high pressure high temperature filter press) over a wide range of parameters including pressure, temperature, and properties of the drilling fluid under dynamic conditions. The aim is to eliminate or reduce the corrosivity of the mud as well as to control the losses. The results showed a lower corrosion rate, 0.0029 mm/year, using P. farcta material in comparison with those obtained by researchers in the previous studies
Audio Encryption Framework Using the Laplace Transformation
Full text linkDigital information, especially multimedia and its applications, has grown exponentially in recent years. It is important to strengthen sophisticated encryption algorithms due to the security needs of these innovative systems. The security of real-time audio applications is ensured in the present study through a framework for encryption. The design framework protects the confidentiality and integrity of voice communications by encrypting audio applications. A modern method of securing communication and protecting data is cryptography. Using cryptography is one of the most important techniques for protecting data and ensuring the security of messaging. The main purpose of this paper is to present a novel encryption scheme that can be used in real-time audio applications. We encrypt the sound using a combination of an infinite series of hyperbolic functions and the Laplace transform, and then decrypt it using the inverse Laplace transform. The modular arithmetic rules are used to generate the key for the coefficients acquired from the transformation. There is no loss of data or noise in the decryption sound. We also put several sound examples to the tes
Evaluation of Radioactivity in Soil Sample from Al-Hadbaa Cement Plant in Nineveh Governorate, Iraq
Full text linkThe fundamental goal of this study is to measure the level of radioactivity in the soil of the area around Al-Hadbaa cement plant, also to evaluate the radiological hazard of radionuclide, gamma-spectroscopy with an HPGe detector with the crystal diameter of 70.6 mm and length of 70 mm has been used to estimate the specific activity of natural radionuclides 226Ra, 232Th, 40K, and artificial radionuclides 137Cs in the fifteen soil samples collected. The results show that the average concentration of specific activity of 226Ra, 232Th, 40K, and 137Cs was 11.17 ± 1.69, 13.38 ± 0.72, 158.36 ± 5.35 Bq/kg, and 1.52 ± 0.19 Bq/kg, respectively. The average specific activity of these radionuclides is discovered to be lower than the global average which is 33 Bq/kg for 226Ra, 30 Bq/kg for 232Th, and 400 Bq/kg for 40K. Radiological hazard indices are determined according to the activity concentration of the radionuclides in the area under study. The outcome of the radiological hazard index is within the globally recognized limit proposed by UNSCEAR which is 1000 μSv/y for annual effective dose and 290 × 10-6 for cancer risk, so it is possible to conclude that there are no radiological hazards as a result of radiation exposure to the workers working in the cement plant as well as the organisms living in the region
Atherogenic Index of Plasma in the Three Trimesters of Pregnancy
Full text linkThis study investigates the change that occurs for atherogenic index of plasma (AIP) which is a very good marker for the evaluation of the risk of atherogenicity and cardiometabolic health. This study indicates the logarithm of the triglyceride and high-density lipoprotein cholesterol (log [TG/HDL-c]). The parameters of triglycerides (TG) and high-density lipoprotein cholesterol (HDL-c) are estimated and compared with the control cases. The AIP is calculated for each case during pregnancy in first, second, and third trimesters separately and each is compared with control cases. The study population comprised (80) women aged between (20–40) years distributed to (20) healthy non-pregnant women, (20) in the first trimester, (20) in the second trimester, and (20) in the third trimester in Koya health centers. The results of this study showed a significant increase in the TG level in both the second and third trimesters of pregnancy compared to the control cases. Whereas, in the first trimester of pregnancy, it can be assumed that there is a non-significant decrease of TG level rather than control cases. As well as the serum levels of HDL for all three trimesters of pregnancy displayed non-significant changes when compared to non-pregnant cases. These data illustrate that the AIP levels during both the second and third trimesters of pregnancy are significantly higher, as compared to control cases, whereas the AIP levels in the first trimester are non-significantly elevated, as
compared with control case