The effect of temperature range from 298 K to 348 K and volume filler content ф on electrical properties of polyethylene PE filled with nickel Ni powders has been investigated. The volume electrical resistivity V  of such composites decreases suddenly by several orders of magnitude at a critical volume concentration (i.e. фc=14.27 Vol.%) ,whereas the dielectric constant   and the A.C electrical conductivity AC  of such composites increase suddenly at a critical volume concentration (i.e. фc=14.27 Vol.%).For volume filler content lower than percolation threshold ф<фc the resistivity decreases with increasing temperature, whereas the dielectric constant and the A.C electrical conductivity of

Quantum dots (QDs) of cadmium sulfide (CdS) was prepared by chemical
reaction method with different potential of hydrogen (pH) values. The
morphological and optical measurements of cadmium sulfide QDs were considered
by atomic force microscopy (AFM), ultraviolet-visible (UV-VIS.) and
photoluminescence (PL) spectrometer respectively. The energy gap (Eg) was
calculated from photoluminescence spectra were found to be about 2.7, 2.6 and 2.5
eV at pH values 8, 10 and 12 respectively for CdS QDs. The decreasing of energy
gaps is rises from the effect the pH solution increases, which in turn leads to the
shifted of the PL spectrum toward red shifted, which creates the energy bands at
surface states are shallow bands.

 In this paper we investigate how do the laminated composites behave mechanically when subjected to external stresses, when reinforced with continuous fibers (mat) and discontinuous fibers (chopped) and to find the effect of the fiber type on the mechanical properties. Laminated composites consisting of wood- wood and Ph-F resin as suitable adhesive were reinforced with different fibers(jute, glass, and carbon).However, two  different methods of reinforcement namely, mat and chopped fibers were utilized. The mechanical properties such as (impact strength, compression strength, tensile strength, shear strength, bending strength, and elasticity modulus) of laminated composites were measured. Fibers reinforced laminated composite

   Synthesis ,characterization of new mono and twin  compounds containing heterocyclic four member ring as, 1,3- diazetine by four steps. The first step; includes  preparation of 2- amino thiazole derivatives [I]_a-c via ring closure reaction between acetophenone derivatives   with thiourea in I₂,  while the second step includes condensation reaction between 2-amino thaizole derivatives[I]_a-c and  p-methoxy benzaldehyde to produce Schiff bases[II]_a-c. The third step includes neculophilic attach from imine group toacetyl chloride to give N- acetyl cross bonding[III]_a-c.Finally ; the  fourth step is completed by the reaction of N- acetyl deri

     A polypyrrole-based ammonia-detection gas sensor was studied in this work. Under a 1.6 V electrodeposition potential, polypyrrole (PPy) was electrochemically synthesized from an aqueous solution of 0.1 M pyrrole and 0.1 M oxalic acid. An extension to the polypyrrole films was applied through electrochemical deposition on indium tin oxide (ITO), using the metal oxide nanoparticles of MgO and WO₃. These films were investigated for their sensing behavior towards NH₃ at different working temperatures and different weight percentages of nanoparticles .The measurements of A.C conductivity were conducted over a frequency range of 10¹-10⁵ Hz and temperature range of 298-423 K .

This research investigates the dielectric properties (impedance, dielectric constant
and dielectric loss) of SiO2\ Ep :TiO2 \ Ep nanocomposite over the frequency range
of (102-106 Hz ) at room temperature. The dielectric material used is epoxy resin,
while nano-sized titanium dioxide (TiO2) with grain size ( 30nm) , oxide silicon
(SiO2) with grain size (12nm) in state volume ratio (0,0.05 ,0.1) .The effect of
gamma by using (CS137) for period time (17) day was studied Radiation caused
decreasing in real and imaginary parts of dielectric constant and impedance .

Co-crystals are new solid forms of drugs that could resolve more than one problem associated with drugs formulations like solubility, stability, bioavailability, mechanical and tableting properties. A preliminary theoretical study for estimating the possible bonding between the co-crystal components (paracetamol and naproxen) was performed using the ChemOffice program. The results revealed a high possibility for bonding between paracetamol and naproxen and indicated the ability of molecular mechanics study to predict the co-crystal design.

       In this work, four different methods were used for the preparation of three different ratios 1:1, 2:1, and 1:2 of paracetamol:naproxen co-crystals. The four

Dielectric measurements were carried on pure and doping potassium sulfate with copper and iron ions samples at 1wt.% and 3wt.% for both of copper and iron. The dielectric constant (ε') decreases exponentially from 2.8 to 1.5 as frequency increase for both dopant which is attributed to the space charge and structural distortion. The dielectric loss (ε") for Cu dopant decrease gradually with frequency. The same behavior for 1%Fe dopant while its 3%Fe doping started from 0.27 then decrease exponential. Band gaps for all samples almost constant around 6 eV.