Apparent molar volume, V?, and viscosity B-coefficient of nicotinc acid in water and in aqueous NaCl solutions have been determined from density and viscosity measurements at (293.15, 298.15, 303.15 and 308.15) K. The experimental density data were evaluated by Masson equation, and the derived, apparent molar volume at infinite dilution, Vo?, and the slope Sv, were interpreted in term of solute-solvent and solute- solute interactions. Transfer apparent molar volumes at infinite dilution of nicotinic acid from water to NaCl solutions at various temperatures have been calculated.The viscosity data have been analyzed using Jones-Dole equation, and the derived parameters, Jones-Dolecoefficient, B,and Falkenhagen coefficient,A, have been also interpreted in terms of solute-solvent and solute-solute interactions respectively. The variation of B coefficient with temperature, (dB/dT), was also determined, the negative values indicate that nicotinic acid in aqueous NaCl solution is structure making. The results were interpreted in terms of complex vitamin-water-co-solute (NaCl) interactions. The free energy, enthalpy, andentropy of activation were calculated using the Nightingale, Benck, and Eyring equations. Free energies of activation of viscous flow ( *1) per mole, and, ( *2) per mole,of solvent and solute, respectively, were also calculated. The effects of soluteson the structure of water were interpreted in terms of viscositiesand the thermodynamic parameters.
In this study, phytoplankton density, chlorophyll-a, and selected physico- chemical parameters were investigated in Erbil wastewater channel. The surveys were carried out monthly from May 2003 to April 2004. Samplings were established on three sites from headwaters to the mouth. The results showed that pH was in alkaline side of neutrality, with significant differences (P<0.05) between sites 1 and 3. TSS concentration decreased from site 1 toward site 2 (mean value, 80.15 to 25.79 mg.l-1). A clear gradual increase in mineral content (TDS) observed from site one of the channel towards the mouthpart. Soluble reactive phosphate has a concentration maximum mean value reached 48.4 µg.l-1 which is recorded in site 2. A high positive relat
... Show MoreThe use of medicinal plant preparations to clean and disinfect root canal infection is gaining popularity. The aim of this study was to evaluate the bioactive composition of leaf extracts of Moringa oleifera plants cultivated in Iraq (specifically Baghdad) and their antimicrobial activity against selected root canal pathogens for potential application in endodontic treatment. Materials and Methods. Moringa leaf extracts were prepared either through cold maceration or warm digestion techniques to perform an ethanolic or aqueous extraction, respectively. Phytochemical detection was performed before thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) to measure flavonoids and phenolic compounds within both
... Show MoreBackground: Parenteral nutrition (PN) is a life‑saving intervention for neonates who are unable to meet their nutritional requirements through enteral feeding. Despite its essential role, PN is frequently associated with metabolic, electrolyte, and hepatobiliary complications. Objective: To evaluate the frequency and pattern of metabolic, electrolyte, and hepatobiliary complications associated with PN administration in neonates. Methods: A prospective case-series study was conducted in two tertiary neonatal intensive care units (NICUs) in Baghdad, Iraq. Term and preterm neonates who received PN for at least five days were included. PN‑related metabolic, electrolyte, hepatobiliary, and hematological complications were recorded an
... Show MoreSpeech enhancement aims to improve speech quality and intelligibility in noisy environments and is important in applications such as hearing aids, mobile communications and automatic speech recognition (ASR). This paper shows a structured review of speech enhancement techniques, classified depending on the channel configuration and signal processing framework. Both traditional and modern approaches are discussed, including classical signal processing methods, machine learning techniques, and recent deep learning-based models. Furthermore, common noise types, widely used speech datasets, and standard evaluation metrics for evaluating speech quality and intelligibility are reviewed. Key challenges such as non-stationary noise, data li
... Show MoreAn investigation was conducted for the improvement of viscosity index of light lubricating oil fraction (40 stock)
obtained from vacuum distillation unit of lube oil plant of Daura Refinery, using solvent extraction process.
In this study furfural solvent was used to extract the undesirable materials which reduce the viscosity index of raw
lubricating oil fraction.
The studied effecting variables of extraction were extraction temperature range from 70 to 110°C, and solvent to oil
ratio range from 1:1 to 4:1 (wt/wt).
The n-d-M method was used for calculation of carbon distribution and structural group analysis of the raffinate
produced from furfural extraction.
Also the three component phase diagram for a mixed-ba
In the cuurent article, the photophysical properties of 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-ethylhexyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione were investigated. The visible absorption bands at 527, 558 and 362 nm in propylene carbonate and the compound was found to be fluorescent in solution and in the plastic film with emission wavelengths between 550- 750 nm. The Stokes Shift of P.C., acetonitrile, diethyl ether, Tetrahydrofuran THF, cyclohexane, dibutyl ether, and dichloromethane DCM are 734, 836, 668, 601, 601, 719, and 804 cm-1 in respectively. The Stokes Shift Δ was less in THF and cyclohexane, than the solvents, which indicates that the energy loss is less between the excitation and fluorescence states. The
... Show MoreThis paper aims at providing the teaching staff members with the necessary skills so as to become capable of tackling various situations, and treating daily problems that face students learning Spanish as a Second Language. This is made as an attempt to make teachers of foreign languages in general acquainted with modern trends of teaching with less complicated methods, specifically in teaching e earlier stages of foreign languages.
Abstracto:
En el presente trabajo pretendemos dotar al docente no nativo de Lenguas extranjeras, con algunos de los métodos necesari
... Show MoreAim: This study aims to determine both the level of knowledge, attitude, and practice in clinical breast examination in women and the relationship between knowledge and practice.Data collection was performed within a three-month period starting from February 2019 on. Subjects and Method: A cross-sectional analytical study included 657 non-randomly selected women visiting primary health care centers in Baghdad city with an average of age between (20-59) years old. Results: Only 51.8% ever heard of clinical breast examination. The mean knowledge score for clinical breast examination was (51.2±44). Only 5.5% of women performed regular clinical breast examinations. Participants who adequately practice clinical breast examinatio
... Show MoreIn this research, the researchers attempted to reveal the non-verbal language in the Holy Qur'an through the hurt of the eye, its communicative effect, and its psychological significance in order to demonstrate the importance of this language. Fold the search ..