The thermal properties of four nematogenic Schiff’s bases, n-butyl-to-n-heptyl of bis (4-n-alkyloxybenzylidine)-2,3,5.6- tetramethyl-1, 4-phenylenediamine, have been studied. The transition temperatures and enthalpies of transition were examined by differential scanning calorimeter (DSC). Several correlations were carried out; those included the relations between transition temperatures, enthalpies and entropies of transition with increasing the
number of carbon atoms in the terminal alkyl chains. In addition, new regular relations were found between the ratio of the enthalpies and of the entropies, for noematic-isotropic transition and crystal-isotropic transition ( ΔΗÎ-i/AHC-I, ΔSN-1/ ASC-I ), with increasing terminal alkyl chain lengths. Many interesting conclusions, concerning the relation
between the anisotropic molecular shape and the thermal properties of the above nematogens, have been arrived at.
In this paper, we analyze several aspects of a hyperbolic univalent function related to convexity properties, by assuming to be the univalent holomorphic function maps of the unit disk onto the hyperbolic convex region ( is an open connected subset of). This assumption leads to the coverage of some of the findings that are started by seeking a convex univalent function distortion property to provide an approximation of the inequality and confirm the form of the lower bound for . A further result was reached by combining the distortion and growth properties for increasing inequality . From the last result, we wanted to demonstrate the effect of the unit disk image on the condition of convexity estimation
... Show MoreIn this paper, chip and powder copper are used as reinforcing phase in polyester matrix to form composites. Mechanical properties such as flexural strength and impact test of polymer reinforcement copper (powder and chip) were done, the maximum flexural strength for the polymer reinforcement with copper (powder and chip) are (85.13 Mpa) and (50.08 Mpa) respectively was obtained, while the maximum observation energy of the impact test for the polymer reinforcement with copper (powder and chip) are (0.85 J) and (0.4 J) respectively
formation constants for the conrdination of aniline pyridine dimethyl sulfoxide dimethyl formamide ethanol dimethylamine have been determined the cordination
The physical, mechanical, electrical and thermal properties containing (Viscosity, curing, adhesion force, Tensile strength, Lap shear strength, Resistively, Electrical conductivity and flammability) of adhesive material that prepared from Nitrocellulose reinforced with graphite particles and aluminum streat. A comparison is made between the properties of adhesive material with varying percentage of graphite powder (0%, 25%, 30%, 35%, 40%) to find out the effect of reinforcement on the adhesive material. The ability of property an electrical was studied through the measurement of conductivity a function of temperature varying. The results of comparison have clearly shown that the increasing of conten
... Show MoreThis search study the effect of particle size of graphite on the mechanical and thermal properties of epoxy composites, where graphite adopted with particle sizes (45,53,75) ?m, respectively, and the percentages by weight (0,1,3,5,7,9)% for each size of this three particle sizes.Mechanical properties represented by the bending (three-point bending) and through which the conclusion is bending stress and modulus of elasticity, thermal properties were either through thermal conductivity tests.The results showed that the ratio(1%) is the maximum value of bending stress at the three particle size and the (45 ?m) is the maximum.Thermal conductivity result show is the maximum value at ratio (1%) of particle size(53 ?m)
Objective: To evaluate male patients complaining of
urethritis clinically according to the isolated organisms.
Method: A total of 100 male patients attending to of
Dermatological and Venereal private clinics for the period
April 2003 to November 2003 were included in the study.
Urethral swab was obtained from each male for culture and
direct immunofluorescence examination was done.
Demographic data was obtained, also.
Results: N. gonorrhoea was the predominate cause of
infection in 22%. A peak of infection was reported in the
second decade of age. Highest rate reported among single
males. A significant association was noticed between
profuse discharge and infection with gonorrhoea.
Conclusion: This
The aim of this study was to evaluate the possibility of using Staphylococcus epidermidis cells as a probiotic to treat some skin infections. For this purpose, S. epidermidis Y73, which is an active bacteriocin producer and non-biofilm forming isolate, was selected among 134 skin isolates through primary and secondary screening. Tryptic soya broth was selected as the best medium to support bacteriocin production, while the optimal pH and temperature for S. epidermidis Y73 growth were 7 and 37°C, respectively, which were invested in the formula preparation. Furthermore, the possibility of using this isolate as a probiotic was investigated by preparing 4 potential cellulosic pads with 4 different formulae whic
... Show MoreAcidity constants at 30co and 0.125 ionic strength have been determined for the Nitrogous bases of nucleic acid; cytocine, uarcil and thymine, and found to be 3.55 x10-19 , 1.44 x10 -19 and 7.24 x10 -20 respectively. Stability constants of these bases with Thorium and uranyl ions have been determined. Results showed that metal ions Thorium and uranyl ions behave as hard acids and the nitrogenum bases behave as Hard bases according to Pearson's definition .Hardness – softness parameters for these ligands were calculated ,stability constants of complexes with metal ions could be arranged as follows :- Cytosine > Uracil > Thymine .
Abstract
In the present work, thermal diffusivity and heat capacity measurements have been investigated in temperature range between RT and 1473 K for different duplex stainless steel supplied by Outokumpu Stainless AB, Sweden. The purpose of this study is to get a reliable thermophysical data of these alloys and to study the effect of microstructure on the thermal diffusivity and heat capacity value. Results show the ferrite content in the duplex stainless steel increased with temperature at equilibrium state. On the other hand, ferrite content increased with increasing Cr/Ni ratio and there is no significant effect of ferrite content on the thermal diffusivity value at room temperature. Furthermore, the heat capacity of all sam
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