Rafidain Journal of Science

A simple and sensitive spectrophotometric method has been developed for the determination of mebendazole (MBZ) in it's pure and tablet form. The method is based on alkaline hydrolysis of MBZ with sodium hydroxide to give primary amine product which reacts with sodium nitrite in an acidic medium (hydrochloric acid) to yield diazotized mebendazole (D-MBZ) which is coupling with m-aminophenol reagent (mAP) to form an azo dye. The absorbance of the azo dye for this suggested method (yellow dye) has been measured at 360 nm. Beer's law for this proposed method is in the range of (0.5-20 µg.ml^-1), the molar absorptivity value is 1.63×10⁴ L.mol^-1.cm^-1 and the Sandell's value index is calculated and equal to 0.018 μg.cm^{- 2}. Also, the limit of detection and the limit of quantification are calculated and equal to 0.1718 μg.ml^-1 and 0.5726µg.ml^-1 respectively. The ratio of the formed azo dye [D-MBZ: mAP] is [2: 1].

The paper describes the synthesis and characterization of a novel macrocyclic ligand. Liquid-liquid extraction studies were conducted to assess the extraction performance of the new macrobicyclic ligand towards copper ions. Selective extraction of heavy metals is highly demanded due to their toxicity and market significance. The results of the experimental studies to determine the best extraction conditions demonstrates pH=9 in the presence of 8.0 ppm of copper (II) in 10 mL with shaking time equal to 30 minutes at 25^o C with using 0.05%   reagent and chloroform as an organic solvent. The article studies the influence of various parameters on the extraction percentage such as; effect of pH, shaking time, type of solvent, temperature, ionic strength, the effect of concentration of metal ion and reagent. IR and HNMR have been used for the characterization of the new macrocyclic compound. Thermodynamic parameters have been calculated based on the experimental results at different temperatures with ΔH (39.91 kJ/ mol), ∆S (0.155 KJ/ mol. K), and ΔG                         (-6.28 KJ/ mol), which, indicates that the reaction is endothermic, randomness and spontaneous. This process has been used for extracting copper ions using atomic absorption spectrometer (AAS).

In this article, the lattice constants, band structure and optical characteristics of ZnO wurtzite structure under various pressures were studied using the generalized gradient approximation (GGA) method. This method is based on the functional density (DFT) Theory, according to the first principle.  The results show that as the pressure increases and the band gap increases, the lattice constants (a and c) decrease. As the pressure increases, the minimum conduction band will move to a higher energy level, and the maximum valence band will move to a lower energy level, thereby increasing the energy band difference. As the pressure increases, the shape of the optical parameter curve remains almost unchanged, and all peaks move to higher energies. The state density, dielectric function, reflectance and absorption coefficient are also calculated. The overview of the spectrum and optical properties is discussed, including the imaginary part of the dielectric function, reflectance and absorption coefficient of wurtzite-type ZnO under environmental conditions. The optical constants indicate that the phase of ZnO wurtzite structure is transparent. We noticed that our measurements are comparable to those observed in the literature.

          In this work, a highly sensitive well-known z-scan technique was employed to study the nonlinear optical properties of Zinc Oxide thin films as a function of low laser fluencies.  The transmissions of the continues-wave red laser diode with wavelength of (650 nm) were measured from the ZnO thin film sample with thickness of (425 nm). The thin film used in this study was deposited on the glass substrates based on atmospheric pressure chemical vapor deposition (APCVD) technique. The measurements were obtained at low laser powers ranging from (1.9-2.5) mW. The results indicated that the nonlinear absorption coefficient, refractive index and the third-order nonlinear optical susceptibility increase with increasing the laser intensity. The obtained curves of the closed aperture showed a positive sign of the nonlinear refractive index which in turn attributed to the self-defocusing of the material. The optical parameters obtained in this work are relatively comparable with that obtained elsewhere. The results also confirm the reliability of the z-scan approach even at low laser intensities.
  

In this research, we discussed the bone density by measuring the total bone mineral density, fat mass and lean mass in a sample of Mosul people, as soon as to compare the accuracy of the BIA approach to DXA in assessing total body compartments and segmental tissue mass. A cross sectional study conducted at DXA laboratory, Physiology Department, College of Medicine, Nineveh University, Mosul-Iraq. A total of 136 persons, 44 males and 92 women, recruited from reviewing of college Medical College Academic Centre and took part in the current study. A highly statistically significant association between BIA and DXA measures for TFM, TLM, and FFM was also found. BIA underestimates total fat mass by 7.24 kg than DXA. BIA approach overestimated muscle mass by 10.1 kg when compared to the DXA. BIA underestimates fat-free mass by 20.67 kg compared to DXA.                                                                                      

Silver-assisted one-step chemical etching (AACE) is a low-cost, straightforward method for producing silicon nanostructures to improve their light absorption; it includes the etching of the wafers in aqueous hydrofluoric acid (HF), silver nitrate (AgNO₃) and nitric acid (HNO₃) solution. Influence of various parameters, such as AgNO₃ concentration (0.47, 0.58, and 1.17 mM), HF concentration (0.67, 0.9, and 1.129 M), HNO₃ concentration (0.12, 0.24, and 0.37 M), etching temperature (40, 50, and 60^oC), and etching time (4, 5, and 6 min), on the Morphological and optical properties of silicon wafers were investigated. The results show that these parameters have a main role in determining the nanostructure size. The reflection measurements show that the minimum reflectance with 11% achieved with 0.58 mM AgNO₃, 1.129 M HF, and 0.12M HNO₃ recipe. Field Emission Scanning Electron Microscopy (FESEM) appears that the morphology of the manufactured silicon is semi-spherical nanostructures with the formation of the porous surface on the surface of the wafers.

The research included study the effect of sodium chloride NaCl salt with concentrations 50, 100, 150 and 200 mM and ascorbic acid concentrations 20, 40 mg/ l^{-1 in the initiation and growth of Helianthus annuus L. callus. The results showed that increasing salt concentration in cultured media led to decrease callus induction from stem segments of seedlings that grown on agar-solidified Murashige and Skoog medium (MS) provided with 1 mg/ l-1} of BA and 0.5 mg/ l^-1 of NAA. This was accompanied by a decrease in the fresh and dry weights of callus, whereas, the addition of ascorbic acid to media containing salt resulted in a restoration of the initiation and growth of callus after 30 days of cultivation. The results also showed that cultivation of samples of callus in MS media with different concentrations of NaCl led to a significant decrease in the indicators of callus growth (fresh and dry weight, salt stress index, absolute and relative rates, callus viability) with an increase in electrolyte leakage of callus cells. The addition of ascorbic acid 20 or 40 mg/ l^-1 to MS media encourages the callus growth indicators above with the superior concentration 20 mg/ l^-1. The presence of ascorbic acid, especially 20 mgl^{-1 in growing media containing NaCl at 150 mM, increased the callus content of ascorbic acid as compare to salt treatment only, after 21 days of cultivation.}

Preparation of the complexes of some transition metal elements with 1,2-DACH  compound and a study its conductivity in water at different temperatures , the determination of its electrolytic behavior and the using of Lee-Wheaton equation in conductivity to study molecular and ionic interference, Determine its type and to calculate the conductivity parameters the ion association constant (KA) , the equivalent conductivity (Λ_𝑂) and the equivalent ionic conductivity (𝜆_𝑂) at the infinite dilution. As well as calculate the values of distance parameter between ions (R) at the lowest value of the standard deviation (𝜎𝛬) And finding the thermodynamic values Δ𝐻, Δ𝐺 and Δ𝑆. The complexes for 1,2-DACH with Co (II), Ni (II), Cu (II) and Mn (II) were prepared and their identification by electrical conductivity and spectral methods such as U.V.-Vis. spectrum and physical properties such as complex color and melting point. These Including the preparation of aqueous solutions with different concentrations of each of the 1,2-DACH complexes with the metal ions Co (II), Ni (II), Cu (II) and Mn (II) and the study of the electrical conductivity of these complexes and their analysis using the computer program of the Kohlrausch equation to study the electrolytic behavior of the complexes by draw the relationship between the equivalent conductivity and the root of the concentration, The program using the Lee-Wheaton equation for asymmetric electrolytes (2:1) In different temperature degrees (283.16, 288.16, 293.16, 298.16, 303.16, 308.16) K to calculate the values of conductivity parameters (𝝀^𝟎_𝑴^𝟐+) ,( 𝝀^𝟎_𝑴𝑿+) ,(𝝈𝚲) ,(𝑲𝑨) ,(𝑹) of each complex.
 

The study of the impact of solar activity on the Earth's climate is an important matter for predicting the change of climate elements for long periods. Most research has been limited to studying the relationship of sunspots with a change in one of the climate elements. In this research, the effect of the solar activities of coronal mass ejections and solar flare on a climatic element in the troposphere, represented by thunderstorms during the winter season in the city of Mosul for the 23 and 24 solar cycles, respectively, was studied. The data on coronal mass ejections were collected from the SOHO/LASCO CME Catalog database and solar flare data were taken from the website National Oceanic and Atmosperic (NOAA). Climatic data on thunderstorms for the winter seasons from the period (1996-2019) were used from the monitoring station in the city of Mosul from the Iraqi General Authority for Meteorology and Seismic Monitoring.The parameters were analyzed using the statistical program (Minitab 19.0). The results showed that there is an inverse relationship between the monthly rates of solar activities with the monthly rate of thunderstorm frequency, with the exception of the rising phase of the solar cycle 24 for the time period (2008-2013), where the results showed the existence of a positive relationship between them

           In this work, cadmium selenide (CdSe) thin films were prepared by two methods of chemical bath deposition (CBD) on glass substrate, where cadmium nitrate Cd (NO₃)₂ and sodium selenosulfite Na₂SeSO₃ were used. The deposition conditions at 70 ^oC temperature and for 6 hours and pH = 9 (during deposition). In the first method the deposition solution was changed every two hours, while the deposition continued without changing the solution in the second method. It was found that switching the solution affects the value of the thickness of the deposition film which increase too about double. The energy gap was reduced by 0.2eV when the solution was switched. As for (XRD) of the films prepared by the solution switched appeared polycrystalline, a hexagonal and cubic structure and growing in (002) direction. A hexagonal crystal with growth in the (002) direction in which the solution was not changed. The (SEM) of the prepared films found that they have spherical, sheets, and flower clusters nano-shapes distributed on the surface.