This research discloses the synthesis of various polyester resins, the polyesters containing homoring aromatic and others heterocyclic were synthesized by the condensation polymerization of suitable monomers (which are containing variety function groups in different structures) with phthalic anhydride. The main objective is synthesis of new polyester with keeping a reasonable electrical insulating behavior. The structural of polymer was characterized by Fourier Transform infra-red spectroscopy FTIR and HNMR. The dielectric constant (real ε' and imaginary parts ε") and AC conductivity (σAC) for all the polyester samples are studied by varying the frequency (30, 50, 70, 90, 120, 300, 500Hz and 1KHZ) at 25⁰ C. Indeed, study of the electri

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

Sixty four local isolated of Klebsiella spp. have been isolated from environment samples (soil and water). These isolates were identified and diagnosis according to phenotype and biochemical tests. These isolates were subjected to primary and secondary screening, to select the isolate with the highest laccase activity. Fifteen isolates chosen from primary screening for screening their enzyme activity in secondary screening. It has been found the Klebsiella(K7) has the highest productivity of the enzyme (12 Unit/ml).Klebsiella(K7) isolate was diagnosis by Vitak 2 system, it was identified asK. pneumonia. The laccase purified was characterization, the experiments showed that: The molecular weight of laccase was 120KD and the optimum pH for th

            In the present study, ( Schiff's bases 6a - 6e) and  (new amids derivatives 6f - 6j) have been synthesized . The glutaroyl chloride(2) has been prepared by the reacting of glutaric acid and thionyl chloride in presence of (DMF) . The new compound bis(4-formylphenyl) glutarate (3) has been Synthesized from reaction of one mole of glutaroyl chloride and two moles of 4-hydroxybenzaldehyde . Compound 4,4'-(glutaroylbis(oxy))dibenzoic acid (4) was Synthesized from one mole of glutaroyl chloride and two moles of 4-hydroxybenzoic acid, while compound bis(4-(chlorocarbonyl)phenyl) glutarate (5) was prepared from 4,4'-(glutaroylbis(oxy))dibenzoic acid and Thionyl chloride . Then Schiff's bases 6a - 6e that prepared

The effect of molecules intersystem crossing (Kisc) on characteristics
(energy and duration) of a Passive Q- switched Laser Pulse has been
studied by mathematical description (rate equations model) for
temporal performance of which was used as a saturable absorber
material (passive switch) with laser. The study shows that the energy
and duration pulse are decreasing while the molecules intersystem
crossing into saturable absorber energy levels is increasing.

Abstract: The power and the size of the final spot of the laser beam reaching the target are very important requirements in most of the laser applications and fields such as medical, military, and scientific, so studying laser propagation in the atmosphere is a very important topic. The propagation of the laser beam through the atmosphere is subject to several attenuation processes that deplete the power and expand the beam. Through the simulation results of the free electron laser within the visible region of the electromagnetic spectrum (400-700nm), it was found that the attenuation increases with decreasing wavelength. Laser propagation in the presence of rain and snow leads to a very large loss of power compared to propagation i

This work aimed to investigate the effect of Diode laser 805 nm on plasmid DNA and RNA
contents of some Gram negative bacteria represented by Escherichia coli and Proteus mirabilis isolates
.Plasmid extraction was done using two methods (Salting out and CTAB method).Different powers and
pulse repetition rates for 805 nm Diode Laser were used to study this effect. Results revealed that the
plasmid profile of the two species were highly affected using (2, 3) W at different frequencies including
5and 10 kHz as compared with 1 kHz while plasmids were gradually disappeared at 1W, 10 kHz. In the
same time the shining of RNA was also decreased gradually then disappeared with increasing powers
especially at 2W and 10 kHz cau

Vitamin A, namely retinol is still the most proper agent for modulating so many biochemical reactions and biological functions in different tissues and organs. In addition to the provitamins A and α, βand γ-carotenoids that are present in various foods from either animal or plant origin, retinoids and rexinoids form the natural and synthetic analogs that are chemically related or unrelated and can be added as food supplements for deficiency disorders of vitamin A or used to alleviate or treat certain health problems such as skin carcinoma, acne, skin aging and dermatitis.