We described herein the synthesized and characterized of new bent and liner core compounds containing thiazolidin-4-one ring[XI-XIII] and [XIV-XVI] respectively. These compounds synthesized by sequence reactions starting from reaction resorcinol or hydroquinone with chloracetyl chloride to yield compounds [I] and [II] ,then the later compounds reactant with 4-hydroxybenzylaldehyde to product dialdehyde compounds [III] and [IV] .The Schiff bases compounds[V-VII] and [VIII-X] synthesized from reaction the compound [III] or [IV] with different aromatic amines, while the bent and liner core mesogens containing thiazolidin-4-one ring [XI-XIII] and [XIV-XVI] synthesized from reaction Schiff bases compounds[V-VII] or [VIII-X] with thioglycolic acid. In addition estrfecation of cinnamic acid with methanol to yield ester compound[XVII]which was converted to their acid hydrazid[XVIII] and the acid hydrazid reacted with glysine in phosphorous oxychloride to yield (5-styryl-1,3,4-oxadiazol-2-yl) methanamine [XIX]. Then reactant the1,3,4-oxadiazol compound[XIX] with dialdehyde compound [III] or [IV] to product new Schiff bases compounds [XX] and [XXI] , afterword added thioglycolic acid to give new thiazolidin-4-one derivatives [XXII] and [XXIII], respectively. The synthesized compounds were characterized by melting points , FTIR ,1HNMR and mass spectroscopy (of some of them).The liquid crystalline properties were studied by hot stage polarized optical microscopy (POM) and differential scanning calorimetry(DSC).All the Schiff bases compounds [V-X] showed liquid crystals phases while thiazolidin-4-one derivatives[XI-XIII],[XIV-XVI]and [XXIII] didn’t show any liquid crystals properties except the compound [XXII] showed enantiotropic nematic phase.
This paper aims to study the effect of circular Y-shaped fin arrangement to improve the low thermal response rates of a double-tube heat exchanger containing Paraffin phase change material (PCM). ANSYS software is employed to perform the computational fluid dynamic (CFD) simulations of the heat exchanger, including fluid flow, heat transfer, and the phase change process. The optimum state of the fin configuration is derived through sensitivity analysis by evaluating the geometrical parameters of the Y-shaped fin. For the same height of the fins (10 mm), the solidification time is reduced by almost 22%, and the discharging rate is enhanced by almost 26% using Y-shaped fins compared with the straight fins. The results demonstrate that the sol
... Show MoreIn the geotechnical and terramechanical engineering applications, precise understandings are yet to be established on the off-road structures interacting with complex soil profiles. Several theoretical and experimental approaches have been used to measure the ultimate bearing capacity of the layered soil, but with a significant level of differences depending on the failure mechanisms assumed. Furthermore, local displacement fields in layered soils are not yet studied well. Here, the bearing capacity of a dense sand layer overlying loose sand beneath a rigid beam is studied under the plain-strain condition. The study employs using digital particle image velocimetry (DPIV) and finite element method (FEM) simulations. In the FEM, an experiment
... Show MoreThe effects of temperature on an exotic aquatic snail Pomacea canaliculata (Lamarck, 1819) collected from the Shatt Al-Arab intertidal zone were investigated. A series of laboratory experiments were conducted during the summer period of 2017. Individuals of new born snails hatched in the laboratory from adult snails were collected from Shatt Al-Arab intertidal zone, and subjected to five fixed temperatures: 15, 25, 35, 40 and 45 Cº, after short term thermal acclimation. The heartbeats (HB) were counted at each temperature level. The results showed significant direct increase of HB from 15 Cº (19.8 HB/min) up to 25 Cº (76 HB/min) (P<0.05) as well as from 25 Cº to 35 Cº (93 HB/min). At 40 Cº the snail HB
... Show MoreThe current study aimed at (identifying the impact of a proposed strategy based on the realistic mathematics theory in the mathematical interrelation among the third intermediate grade students), two samples from the third intermediate grade were tested in a school affiliated to Rusafa I General education Directorate in Baghdad for the academic year (2022-2021)the experimental group will study according to the proposed strategy and it consisted of (30) female students , the control group will study through the traditional method and the number of its students is (30), thus the study sample consisted of (60) female students, the two groups were equalized in the variables (age in months, intelligence, prior knowledge) and to achieve the study
... Show MoreIn this research, the kinetic studies of four isoenzymes of Asprtate aminotransferase, which partially purified from the urine of chronic renal failure patients were carried out .The four isoenzymes were obeyed Michaelis-Menton's equation and the optimum concentration of their substrate (Aspartic acid) was (166.5x10-3) mole/liter,and their Km values were determined. Four isoenzymesI,II,III,IV have shown an optimum pH at 7.4.The four isoenzymes obeyed Arrhenius equation up to 37º C and their Ea and Q10 constants were determined .
Background: During pregnancy many physiological, anatomical and biochemical changes take place that affect almost all body systems. In the oral pregnant women have serious changes such as more sever dental caries. This study was conducted to measure dental caries severity and selected salivary variables (salivary flow rate, PH and viscosity)and to find the relation of dental caries with these salivary variables. Subjects, materials and methods: The study group consisted of 60 pregnant women that were divided into three equal groups according to trimester (20 pregnant women in each trimester).They were selected randomly from the Maternal and Child Health Care Centers in Baghdad city, the age range was 20-25 years. In addition to 20 unmarried
... Show MoreThis thesis aims to show the effects of the development of the traditional manual system of the tax accounting process to the electronic system by the activation of the tax identification numbers (TINs) mechanism. The impact of this development is facilitating the tax accounting process, tax fraudand thus increasing the tax outcome.To prove the research hypothesis, an electronic system was designed based on income tax report, estimation note of individuals, in additional to using Adobe Dreamweaver application to write PHP, HTML, Javascript, and CSS web languages to implement the proposed system. The research reached a set of conclusions, the most important of which is; not enough the communication methods between the Genera
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