The new compounds synthesized by sequence reactions starting from a reaction of 4-hydroxybenzaldehyde with 1,5-dibromo pentane to produce dialdehyde)I( .Then compound )I( reacted with different aromatic amines to give schiff bases )IIIV(,thereafter added acetyl chloride to schiff bases to yield N-acyl derivatives)VVII(.While1,3-diazetine derivatives)VIII-X( were synthesized from the reaction of N-acyl derivatives with sodium azide.The reaction of thiourea with N-acyl compounds led to formation of thiourea derivatives (XI-XIII).Finally, the pyrimidine compounds )XIV-XVI( were synthesized by ring closure reaction of compounds(XIXIII) with diethyl malonate.The synthesized compounds were characterized by measurements of melting points,FTIR,1H-NMR and mass spectroscopy for some prepared compounds.The liquid crystalline properties were studied by hot stage polarizing microscopy and differential scanning calorimetry DSC for compound (IX). The compounds)VI(, (IX),(XII) and (XV) display enantiotropic nematic mesophase, while other compounds(V),(VII),( VIII),(X),(XI),(XIII),(XIV) and( XVI) did not show any liquid crystalline properties.
Drilling with casing (DWC) can be considered as a modern drilling technique in which both of drilling and casing operations done in the same time by using the casing to transfer the hydraulic and mechanical power to the bit instead of traditional drilling string. To overcome oil well control, minimizing the total cost through enhancing drilling efficiency, drilling with casing was proposed as an enabling technology.
Two surface sections (17 1/2 - and 12 1/4- inch) were drilled successfully in Rumaila oil field with casing strings which reached 655m and 1524m measured depths respectively.
By using DWC technique, the total drill/case phase time was reduced up to 20% comparing to conventional
... Show MoreThis work presents external morphological study of the leafhopper Empoasca decedens
Paoli, 1932 particularly male genitalia, which were dissected and illustrated.
The genus Empoasca Walsh (Typhlocybinae: Empoascini) contains small, slender, fragile
and generally green leafhoppers. The overall length ranges from 3-3.5 mm. Members of this
genus are charachterized by their uniformly green color, inner and outer apical cells of
forewing not attaining wing apex, second and third apical cells are sessile or triangular or
even short stalked, submarginal vein of hindwing extends around wing apex and turned
beneath costal margin, apical thirds of tibiae and tarsal segments including claws are
prominently green while other
he study aims to build a model that revolves around the main question of the role of strategic agility (SA) in enhancing organizational excellence (OE). For the purpose of achieving OE and to determine the extent of interest and knowledge of managers at the Midwest Refineries Company (MRC) on the theoretical and practical implications, and on the performance foundations of these two vital variables with the aim of continuous improvement. A questionnaire was used and distributed to a random sample of 54 managers in this important energy production company. The study followed the descriptive analytical approach to answer the questions raised. The study model and dimensions were built according to reference models, most notably the models (Al-
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Objective: Dental caries is a chronic infectious disease that is prevalent worldwide in all age groups. Numerous attempts have been made to develop conservative approaches to halt caries progression and restore enamel defects. This study aimed to investigate the effect of applying grape seed extract and chicken eggshell extract on the microhardness of demineralized enamel in permanent teeth. Methods: Forty-eight sound upper first premolars were used. Following demineralization with the demineralizing solution for 96 hours, they were distributed into four groups consistent with the treatment agent used: group A was treated with casein phosphopeptide amorphous calcium phosphate (as a control group), group B was treated with grape se
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The increasing anti-bacterial drug resistance is one of the biggest challenges facing doctors around the globe, so finding alternative treatments is one of the ideal options to overcome this problem. The cruciferous family is one of the wealthiest plants worldwide because it contains the most important secondary metabolites, glucosinolates, known for their anti-microbial properties. The present study aimed to evaluate the anti-bacterial effect of glucosinolates (Sinigrin) against eight bacterial isolates (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Actinomyces, Proteus mirabilis and Streptococcus pneumoniae). The current study investigated six concentrations of pure
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Rapid and continuous developments and changes in the modern business environment in all areas of economic, environmental, social, technology and communications push economic units to search for modern methods and methodologies to produce products at low cost as well as produce products that meet the wishes of customers in terms of quality and environment to maintain their market position, and accounting for the costs of the flow of materials is one of the most prominent environmental management accounting techniques capable of providing information to help produce
This study deals with an important area in the field of linguistics, namely person deixis.
The study aims at: (1) Describing the notion of deixis, its importance, and its place in the field
of linguistics, (2) Presenting a detailed illustration of person deixis, and (3) Conducting an
analysis of person deixis in one of Synge‟s plays Riders to The Sea according to Levinson‟s
model. The most important aim of these three is the third one (the analysis). To achieve this
aim, the researcher depends on Levinson‟s (1983) descriptive approach. According to the
descriptive approach of deixis, the category of person deixis can be defined as the encoding of
the participant roles in the speech situation. This encoding is r