An environmentally begnin second derivative spectrometric approach was developed for the estimation of the dissociation constants pKa(s) of metformin, a common anti-diabetic drug. The ultraviolet spectra of the aqueous solution of metformin were measured at different acidities, then the second derivative of each spectrum was graphed. The overlaid second derivative graphs exhibited two isobestic points at 225.5 nm and 244 nm pointing out to the presence of two dissociation constants for metformin pKa1 and pKa2, respectively. The method was validated by evaluating the reproducibility of the acquired results by comparing the estimated values of the dissociation constants of two different strategies that show excellent matching. As well as, the whole procedure was repeated with a new set of standard solutions and buffers for further verification. The average calculated values of pKa1 and pKa2 were found to be 2.72±0.01 and 11.61±0.08, with correlation coefficients ( R2) of 0.9916 and 0.9614, respectively. The established method was fast, affordable, reproducible, and the mean pKa values obtained were accurate and can be applied for the estimation of the dissociation constants of other active pharmaceutical compounds
This work involved the successful synthesis of three new Schiff base complexes, including Ni(II), Mn(II), and Cu(II) complexes. The Schiff base ligand was created by reacting the malonyldihydrazide molecule with naphthaldehyde, and the final step involved reacting the ligand with the corresponding metallic chloride yielding pure target complexes. FTIR, 1 H NMR, 13 C NMR, mass, and UV/Vis spectroscopies were used to comprehensively characterize the produced complexes. These substances have been employed in this study to photo-stabilize polystyrene (PS) and lessen the photo-degradation of its polymeric chains. Several methods, including FTIR, weight loss, viscosity average molecular weight, light and atomic force microscopy, and energy disper
... Show MoreThis paper numerically and theoretically investigates the optical and thermal performance of a parabolic trough collector PTC system. Many numerical simulations and theoretical analyses are conducted to demonstrate the influence of the receiver geometry and shifting from the focal position on the optical performance. The examined receiver geometries are circular, square, triangular, elliptical, and the new circular–square combined geometry is named as channel receiver. The thermal performance of PTC is examined for different volume flow rates theoretically in the range of (0.36 to 2.4 lpm). The results show that the best optical design is the channel receiver with an intercept factor of 84%, while the worst is the elliptical receiver with
... Show MoreThis work provides a historical overview of water storage tanks used for solar energy collection, with a focus on the impact of different geometric configurations on thermal performance and energy storage efficiency. The designs of cylindrical, spherical, rectangular and triangular tanks were reviewed to analyse their effects on thermal gradients, heat retention and energy storage capacity. Within the scope of nominal processes, the study primarily aimed to identify the factors influencing the choice of tank shape in terms of size, capacity and aspect ratio. Another key objective was to assess what enhances heat storage in the tank to improve thermal efficiency. Comparing cylindrical shapes to other shapes, such as spherical, rectan
... Show MoreA new, easy‐to‐manufacture, and low‐cost integrated cubical solar collector tank for domestic usage is concerned in this work. Three models are prepared, side by side, and tested to point out their seasonal performance. Tank Model I has three vertical sides, black painted and glazed to act as an absorber; the other sides are insulated. Tank Model II has two black painted and glazed sides, with four insulated surfaces. The models are south‐oriented at different positions and tested versus the conventional tank (Model III) to validate and assess their performance in summer and winter. In summer, the temperatures in Models I and II are lower than those for Model III since they have insulated sid
ABSTRACT Background: Blood donation is process obtaining, analyzing, preparing, and preserving blood and its many components essential for life-saving that enhances health and lowers mortality rates. Despite the fact that giving blood is frequently demonstrated to be a voluntary service, certain studies highlight a number of factors that affect blood donations such as Gender, past donor experiences including syncopal reactions, venipuncture pain, anxiety, and donor satisfaction, all have an impact on the decision to donate blood.in addition, one of the main reasons donors reject to donate blood is pain associated with venipuncture. Aim: Evaluate the effectiveness of shotblocker on pain during venipuncture in adult blood donors compared to
... Show MoreBackground: The ideal maxillofacial prosthesis should have fine and thin boundaries that bindwith the surrounding facial structures and possess high tear strength.This study aims to determinethe best percentages of nanofiller (TiO2) and intrinsic pigment (silicone functional intrinsic) thatcould be mixed in as additives to improve the tear strength of Cosmesil M511 andVST50F siliconeelastomers with the least effect on their hardness.Materials and Methods: In this in vitro experimental study, a total of 80 samples, 40 for eachelastomer, were fabricated. Each elastomer sample was split into two equal groups to test for tearstrength and Shore A hardness. Each group consisted of 20 samples, including 10 control sampleswithout additives and 10 e
... Show MoreThe reaction of [Benzoyl hydrazine] with [Diphenyl mono oxime] and Glacial acetic acid was carried out in methanol gave a new tridentate ligand [Benzoic acid (2-hydroxyimino- 1, 2-diphyneylethylidene) - hydrazide]. This ligand was reacted with some metal ions (Fe(II), Co(II), Ni(II), and Cu(II)) in methanol with (1:1) metal : ligand ratio to give a series of new complexes of the general formula [M(L)Cl2.H2O], where M= Fe(11), Co(11), Ni(11) and Cu(11). All compounds were characterized by spectroscopic methods (I.R, UV-Vis), elemental microanalysis (C.H.N), atomic absorption, magnetic susceptibility, and conductivity measurements. From the obtained data the proposed molecular structures were suggested for the complexes of Fe
... Show MoreDiabetic mellitus is one of the main risk factors of fungal infections because poor glycemic control is associated with a high level of glucose in blood and saliva which could be treated as nutrient to fungi. This study aimed to isolate and identification of pathogenic fungi from diabetic patient. 140 samples were taken from different places of human body from the national center of diabetic patients that related to Mustansiriyah University / college of medicine and Al-yarmuk Hospital in Baghdad. 84 sample (60%) tested positive to fungi and 56 sample (40%) tested negative to fungi. The most frequented fungi isolated have been chosen for molecular identification by PCR (Millerozyma farinosa and Candida orthopsilosis) using specific pri
... Show MoreEight new complexes with the general formula [M(L)2(H2O)2] were prepared resulting from the reaction of the new Schiff base ligand [(E)-5- ((2-hydroxybenzylidene)amino)-2-phenyl-2,4-dihydro-3H-pyrazol-3- one(L)] with metal ions [manganese, cadmium, zinc, copper, nickel, cobalt, Mercury Bivalent and tetravalent platinum. This ligand was derived from the reaction of the amine (5-amino-2-phenyl-2,4-dihydro3H-pyrazol-3-one) with Salicylaldehyde, which is linked to the metal ions via two atoms. The nitrogen is the isomethene group, and the oxygen is the hydroxide group of the pyrazoline ring. The prepared compounds were characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy, and ultraviolet spectroscopy, and from the
... Show MoreThe current study was to examine the reliability and effectiveness of using most abundant, inexpensive waste in the form of scrap raw zero valent aluminum ZVAI and zero valent iron ZVI for the capture, retard, and removal of one of the most serious and hazardous heavy metals cadmium dissolved in water. Batch tests were conducted to examine contact time (0-250) min, sorbent dose (0.25-1 g ZVAI/100 mL and 2-8 g ZVI/100 mL), initial pH (3-6), pollutant concentration of 50mg/L initially, and speed of agitation (0-250) rpm . Maximum contaminant removal efficiency corresponding to (90 %) for cadmium at 250 min contact time, 1g ZVAI/ 6g ZVI sorbent mass ratio, pH 5.5, pollutant concentration of 50 mg/L initially, and 250 rpm agitation speed wer
... Show More