Preferred Language
Articles
/
bsj-7523
Kinetic Study of Polymerization Isopropylacrylamide in Aqueous Solution
...Show More Authors

An experimental of kinetics investigation of the solution free radical polymerization of isopropylacrylamide (IPAM) initiated with potassium persulfate (PPS) was conducted. The reactions were carried out at constant temperature of 60 °C in distilled water under unstirred and inert conditions. Using the well-known conversion vs. time technique, the effects of initiator and monomer concentration on the rate of polymerization (Rp) were investigated over a wide range. Under the conditions of our work, the orders 0.38 and 1.68 were found with respect to initiator and monomer, respectively. However, the rate of polymerization (Rp) is not straight forwardly corresponding monomer concentration. The value 46.11 kJ mol1 was determined as the overall activation energy of polymerization, which is not satisfactory with the value of most thermal initiated monomers. Rp for IPAM in dimethyl formamide, dimethyl sulfoxide, and distilled water using PPS as initiator at 60 oC, was checked. An increase in solvent polarity has slightly increased (Rp) value. The effect of using different concentrations of PPS 0.001, 0.002, 0.003 and 0.004 mol dm-3, on the average degree of polymerization (DPn), was also studied, based on viscosity results obtained using distilled water at 20 oC. The results revealed that an increase in the initiator concentration has an effect in lowering (DP) values.

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Aug 28 2019
Journal Name
International Journal Of Drug Delivery Technology
Synthesis, Characterization and Screening their Antibactrial Activity of some New Oxazepine and Diazepine Compounds Containing 1,3,4-Oxadiazole Ring Derived from L-Ascorbic Acid
...Show More Authors

The search involve the synthesis of some new 1,3-oxazepine and 1,3-diazepine derivatives were synthesized from Schiff base. The Schiff base (VIII) prepared from reaction of aldehyde (IV) derived from L-ascorbic acid with aromatic amine ([2-(4- nitrophenyl)-5-(4-aminophenyl)-1,3,4-oxadiazole] (VII). Oxazepine compounds (IX-XI) were synthesized from the cyclic condensation of Schiff base (VIII) with (maleic, phthalic and 3-nitrophthalic) anhydride, compounds (IX-XI) that were reacted with p-methoxyaniline to give diazepine derivatives (XII-XIV). The structures of the new synthesized compounds have been confirmed by physical properties and spectroscopy measurements such as FTIR, and some of them by 1 H-NMR, 13 CNMR, Mass, and evaluated

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (2)
Scopus Crossref
Publication Date
Tue Jan 01 2019
Journal Name
الأستاذ
Teaching-learning design according to constructivist theory models and its impact on the achievement of chemistry among second-year intermediate school female students
...Show More Authors

Preview PDF
Publication Date
Wed Jul 08 2009
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
Complexeation Behavior of CoII, NiII, CuII, ZnII, and CdII Ions Toward Schiff Base Derived From 2, 4 -Dihydroxy Benzaldehyde and O-Phenylene Diamine
...Show More Authors

bstract The aim of this work covers the synthesis and characterization of the new tertra dentate ligand (H4L) containing (N and O) as donor set atoms kind (N2O2) where: H4L=Bis-1,2 (2,4- dihydroxybenzylediene phylinediamine . The preparation of ligand contains reaction 2, 4 - Dihydroxy benzaldehyde and o-phenylene diamine . Schiff base was reacted with some metal ions in the presence of methanol to give the complexes in the general formula [M (H2L)] where: MII = Co, Ni, Cu, Zn, Cd. All compounds were characterized by spectroscopic methods I.R , U.V.-Vis, metal content and molar conductivity measurements, showed that the complexes are non-electrolyte. The proposed geometry for all of the proposed complexes was a tetrahedral while Ni complex

... Show More
Publication Date
Mon May 01 2017
Journal Name
Al-mustansiriyah Journal Of Science
Synthesis, characterization and antibacterial Evaluation for mixed-ligand Complexes of Nickle (II), Manganese (II), Copper (II), Cobalt (II) and Mercury (II) with Tetradentate
...Show More Authors

Publication Date
Tue Mar 19 2024
Journal Name
Baghdad Science Journal
Synthesis, Spectroscopic, and Characterization of Novel Nano Sized Mannich Base Complexes with Pt (IV) and Au (III) Ions and Assessing Their Antioxidants Activity
...Show More Authors

في هذا البحث تم تحضير المركبات المعدنية النانوية الجديدة لأيونات البلاتين 4+و الذهب 3+ مع ليكاند قاعدة مانخ جديد مشتق من السيبروفلوكساسين بطريقة الموجات فوق الصوتية. تم تشخيص المعقدات النانوية والليكاند الجديد بأستخدام  تقنيات فيزيائية و كيميائية مختلفة مثل أطياف الاشعة تحت الحمراء، حيود الاشعة السينية ، المجهر الالكتروني الماسح ، المجهر الالكتروني النافذ و مجهر القوة الذرية.  تم تحديد نشاط مضادات الأك

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Between Nelson-Olson Method and Two-Stage Limited Dependent Variables (2SLDV ) Method for the Estimation of a Simultaneous Equations System (Tobit Model)
...Show More Authors

This study relates to  the estimation of  a simultaneous equations system for the Tobit model where the dependent variables  ( )  are limited, and this will affect the method to choose the good estimator. So, we will use new estimations methods  different from the classical methods, which if used in such a case, will produce biased and inconsistent estimators which is (Nelson-Olson) method  and  Two- Stage limited dependent variables(2SLDV) method  to get of estimators that hold characteristics the good estimator .

That is , parameters will be estim

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jun 24 2024
Journal Name
International Tinnitus Journal
Distribution of HPV Genotypes 16 and 18 among Resected Tonsillar Tissues from Pediatric Patients Operated for Non- Oncologic Nasopharyngeal and Palatine Tonsillar Hypertrophies
...Show More Authors

Background: Recent advancements in molecular techniques have identified over 450 genotypes of Human Papillomavirus (HPV), classified into low- and high-oncogenic risk categories. The rise in high-oncogenic risk HPV genotypes has been linked to various cancers, including those affecting the oral, oropharyngeal, and nasopharyngeal regions in both pediatric and adult populations. Methods: In this study, a cohort of 102 tonsillar tissue samples was included. This comprised 40 specimens from pediatric patients aged 4 to 9 years with nasopharyngeal adenoid hypertrophies, and 42 specimens from pediatric patients aged 5 to 12 years with palatine tonsillar hypertrophies. Among the 82 tonsillar tissue samples analyzed, 38 were from pediatric patients

... Show More
Scopus
Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Between Ordinary Methods (LS,IV) and Robust Methods (2SWLS,LTS,RA) to estimate the Parameters of ARX(1,1,1) Model for Electric Loads
...Show More Authors

 

Abstract:

The models of time series often suffer from the problem of the existence of outliers ​​that accompany the data collection process for many reasons, their existence may have a significant impact on the estimation of the parameters of the studied model. Access to highly efficient estimators  is one of the most important stages of statistical analysis, And it is therefore important to choose the appropriate methods to obtain good  estimators. The aim of this research is to compare the ordinary estimators and the robust estimators of the estimation of the parameters of

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
Synthesis and characterization of ligands derived 2-hydroxy-1- naphthaldehyde and their complexes with divalent metal ions (Mn+2, Fe+2, Ni +2)
...Show More Authors

In this work, Schiff base ligands L1: N, N-bis (2-hydroxy-1-naphthaldehyde) hydrazine, L2: N, N-bis (salicylidene) hydrazine, and L3:N –salicylidene- hydrazine were synthesized by condensation reaction. The prepared ligands were reacted with specific divalent metal ions such as (Mn2+, Fe2+, Ni2+) to prepare their complexes. The ligands and complexes were characterized by C.H.N, FT-IR, UV-Vis, solubility, melting point and magnetic susceptibility measurements. The results show that the ligands of complexes (Mn2+, Fe2+) have octahedral geometry while the ligands of complexes (Ni2+) have tetrahedral geometry.

View Publication Preview PDF
Crossref
Publication Date
Tue Sep 28 2021
Journal Name
Journal Of The College Of Education For Women
An Estimated Answer of a Condition between the Interpretive Structure and Surface Structure: Al-Qurtubi’s Tafseer as a Model: عمر عقلة خليف الدعجة
...Show More Authors

This present work is concerned with one of the syntactic issues that has been researched by many linguists, grammarians, and specialists in Islamic studies, the estimated answer to a condition. However, this topic is researched this time by examining Imam Al-Qurtbi’s opinions in interpreting related ayas from the holly Quraan in his book (Collector of Quranic Rules) or its transliteration (Al-Jami’ Li Ahkam Al-Quran). Such a step involves commenting on, tracking what Al-Qurtbi said in this regard, discussing it from the points of view of other grammarians, and judging  it accordingly, taking into account the apparent surface structures of the examples collected. To achieve this objective, the inductive analytical approach has be

... Show More
View Publication Preview PDF
Crossref