A new two series of liquid crystalline Schiff bases containing thiazole moiety with different length of alkoxy spacer were synthesized, and the relation between the spacer length and the liquid crystalline behavior was investigated. The molecular structures of these compounds were performed by elemental analysis and FTIR, 1HNMR spectroscopy. The liquid crystalline properties were examined by hot stage optical polarizing microscopy (OPM) and differential scanning calorimetry (DSC). All compouns of the two series display liquid crystalline nematic mesophase. The liquid crystalline behaviour has been analyzed in terms of structural property relationship
Oscillation criterion is investigated for all solutions of the first-order linear neutral differential equations with positive and negative coefficients. Some sufficient conditions are established so that every solution of eq.(1.1) oscillate. Generalizing of some results in [4] and [5] are given. Examples are given to illustrated our main results.
Abstract:
The current research aims to distinguish the talent for the kindergarten
children and its relation with some changes . The research included ( 170 )
child (male , female ) from the kindergarten children on the year 2009 – 2010
the researcher had used PRED meter to achieve the goals of this research
after being sure from the honesty and the prove and the ( person ) connection
coefficient had been used to discover the relation between the talent and the
changes which had been mentioned in the research . The result proved that
the children had talents the toys and the educational scientifically scholarship
finally the researcher had presented some recommendations and suggestions
for other studies .<
This paper presents an analytical study on the serviceability of reinforced concrete gable roof beams with openings of different sizes, based on an experimental study which includes 13 concrete gable roof beams with openings under static loading. For deflection and crack widths under static loading at service stage, a developed unified calculation procedure has been submitted, which includes prismatic beams with one opening subjected to flexure concentrated force. The deflection has been calculated with two methods: the first method calculated deflections via relevant equations and the second was Direct Stiffness Method in which the beam is treated as a structural member with several segments constituting the portions with solid sec
... Show MoreIn recent years, there has been a rapid development in research on high performance ceramics for mechanical, electrical and medical industries. This development will be shown for alumina as a representative for oxide ceramics powders.
Dry–pressing forming technique was used to prepare different ceramic compacts for alumina grafted by polymethacrylate polymers. All Alumina compact were fired firstly at 1200 ◌ْ C, then
at 1600 ◌ْ C.
Mechanical strength was examined in different means, some
depends on compression and other depends on impact. Hardness was
also measured .The results obtained were compared with that of
Alumina compact prepared under the same condition from Alumina
especially made for pressing .
Increasing need for our youth to effective dialogue at the present time, due to the nature of the era in which live, as it abounded risk of intellectual and cultural invasion.Moreover, the need to ensure that the dialogue between the members of the community to confront the many issues of contemporary society in various fields, politically, socially and economically, culturally and religiouslyThe absence of effective dialogue, or the consequent rejection of many of the negative aspects of social and cultural Kaezzlh coup and inertia and ignore the mental capacity of some non-existent among others.The importance of effective dialogue in being the most important foundations of social life a
... Show MoreAvery large numbers of articles are made by powder metallurgical methods using electrolytically reduced metal powders. Iron powder is one of these powders which play an important role in this field. Its preparation by electrolytic method is economic in comparison with the traditional methods (Atomization and carbonyl processes).
An electrochemical cell consisting of two electrodes (stainless steel cathode and iron anode, 99.9%) was used to study the electrolytic preparation of iron powder with particle size less than 106µm directly as powde1y form. Ferrous sulphate electrolyte was used containing sodium chloride as a stabilizing agent. The produced powder was thoroughly washed with an acidified distilled water and absolute ethan
... Show More