This study deals with the estimation of critical load of unidirectional polymer matrix composite plates by using experimental and finite element techniques at different fiber angles and fiber volume fraction of the composite plate.

            Buckling analysis illustrated that the critical load decreases in nonlinear relationship with the increase of the fiber angle and that it increases with the increase of the fiber volume fraction.

            The results show that the maximum value of the critical load is (629.54 N/m) at (q = 0°) and (V_f = 40 %) for the finite element method, while the minimum val

The use of composite materials has vastly increased in recent years. Great interest is therefore developed in the damage detection of composites using non- destructive test methods. Several approaches have been applied to obtain information about the existence and location of the faults. This paper used the vibration response of a composite plate to detect and localize delamination defect based on the modal analysis. Experiments are conducted to validate the developed model. A two-dimensional finite element model for multi-layered composites with internal delamination is established. FEM program are built for plates under different boundary conditions. Natural frequencies and modal displacements of the intact and damaged

In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.

This study outlines the synthesis of substituted 1,2,4-triazole derivatives through the cyclization reaction of thiourea derivatives. The process begins with the reaction of different halides with KSCN to produce isothiocyanate derivatives. then followed by a reaction with isonicotinic acid hydrazide to yield thioureas (1-6), with a yield rate of (72-88%). Then, compounds (1-6) were treated with alkaline medium 4 N (NaOH) to produced 1,2,4-triazole derivatives (7-12) with a yield (51-69%).The structure of the prepared compounds was characterized using FTIR,1HNMR and 13CNMR spectroscopy. Some of the synthesized compounds were tested for antimicrobial activity when, compound 9 showed strong activity against gram positive bacteria (Sta

The most important environmental constraints at the present time
is the accumulation of glass waste (transparent glass bottles). A lot of
experiments and research have been made on waste and recycling
glass to get use it as much as possible. This research using recycling
of locally waste colorless glass to turn them into raw materials as
alternative of certain percentages of cement to save the environment
from glass waste and reduce some of the disadvantages of cement
with conserving the mechanical and physical properties of concrete
made. A set of required samples were prepared for mechanical test
with different weight percentage of waste glass (2%, 4%, 5%, 6%,
8%, 10%, 15%, 20% and 25%). American standard

Metal complexes of Cu (II), Fe (III) and Mn (II) with Quinaldic acid (L1) and 1, 10-Phenathroline (L2) are synthesized and characterized by standaral physic- chemical procedures (element analysis, metal analysis, FTIR, Uv-Vis, magnetic moment and conductometeric measurements). On the base of these studies, mononuclear and six coordinated octahedral geometry and nonelectrolyte of these complexes have been proposed. The standard heat of formation (?Hºf) and binding energy (?Eb) for the free ligands and their complexes are calculated by using the PM3 method at 273K of Hyperchem.-8 program. The complexes are more stable than their ligands. Moreover, the electrostatic potential of free ligands are measured to investigate the reactive site of th

In this study NiO - CoO bimetallic catalysts are prepared with two Ni/Co ratios (70:30 and 80: 20) using the precipitation method of nitrate salts. The effects of Ni /Co ratio and preparation methods on the catalyst are analyzed by using different characterization techniques, i.e. atomic absorption (AA) , XRD, surface area and pore volume measurements according to the BET method . The results indicate that the best catalyst is the one containing the percentage of Ni :Co ( 70 : 30 ). Experiments indicate that the optimal conditions to prepare catalyst are stirring for three hours at a temperature of 60oC of the preparation , pH= (8-9) , calcination temperature at 400oC for two hours

Pulsatile drug delivery systems are time-controlled dosage forms which are designed to release the active pharmaceutical ingredient after a predetermined lag time to synchronize the disease circadian rhythm. A migraine shows circadian rhythm with a marked increase in attacks between 6 a.m. and 8 a.m.

Sumatriptan is a selective agonist at serotonin (5-Hydroxy tryptamine1  (5-HT1))receptors, is an effective treatment for acute migraine attacks.

The aim of this work is to prepare time-controlled press-coated tablet with a lag time of 5.45 hrs.

Six formulas of fast dissolving core tablets and three formulas of press-coated tablets were prepared by using direct compression method using different variables to prepa