The aim of this study is to investigate the behavior of composite castellated beam in which the concrete slab and steel beam connected together with headed studs shear connectors. Four simply supported composite beams with various degree of castellation were tested under two point static loads. One of these beams was built up using standard steel beam, i.e. without web openings, to be a reference beam. The other three beams were fabricated from the same steel I-section with various three castellation ratios, (25, 35, and 45) %. In all beams the concrete slab has the same section and properties. Deflection at mid span of all beams was measured at each 10 kN load increment. The test results show that the castellation process leads to increase the moment capacity of composite beams at permissible deflection that is (span/360) in the range of (11- 96) %. On the other hand, the maximum measured deflection was reduced in the range of (7.8 – 27.1) %.
In this paper the reinforced materials manufactured from steel continues fibers are used in Aluminum matrix to build a composite material. Most of researches concentrated on reinforced materials and its position in the matrix according to its size and distribution, and their effects on the magnitude of different kinds of the stresses, so this paper presents and concentrate on the geometrical shape of reinforced material and its effects on the internal stresses and strains on the composite strength using FEM as a method for analysis after loaded by certain force showing the deference magnitudes of stresses according to the different geometrical shapes of reinforced materials.
A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the
... Show MoreBackground: The aim of this study was to measure the radiopacity (RO) of modified microhybrid composite resins by adding 2 types of nanofillers (Zinc Oxide and Calcium Carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. Materials and Methods: Two types of composite resin were used (Microhybrid composite MH Quadrent anterior shine and Nanofilled composite resin Filtek Z350 XT), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. The material samples were radiographed together with the aluminum step wedge. The density of the specimens was determined with a transmission densitometer and was expressed in term of
... Show MoreStatic loads exposing to mechanical components can cause cracks, which are lead to form stress concentration regions causing the failure of structure. Generally, from 80% to 90% of structure failure is due to initiation of the cracks. Therefore, it is necessary to repair the crack and reduce its effect on the structure where the effect of the crack is modelled as an additional flexibility to the structure. In the last few years, piezoelectric materials have been considered as one of the most favourable repairing techniques. The piezoelectric material converts the applied voltage on it to a bending moment to counter the bending moment caused by the external load on the beam at the crack location. In this study, the design of the piez
... Show MoreThe present research had dealt with preparing bars with the length of about (13 cm) and adiametar of (1.5 cm) of composite materials with metal matrix represented by (Al-Cu-Mg) alloy cast enforced by (ZrO2) particles with chosen weight percentages (1.5, 2.5 ,3.5, 5.5 %). The base cast and the composite materials were prepared by casting method by uses vortex Technique inorder to fix up (ZrO2) particles in homogeneous way on the base cast. In addition to that, two main groups of composite materials were prepared depending on the particles size of (ZrO2) , respectively. &n
... Show MoreThe experimental study showed the use of closed cavity wall (the thickness of the cavity 5cm) made a percentage reduction in the cooling load caused by heat gain from the wall by (21.5 %) compared with the conventional wall. also the thermal resistance of the closed cavity was an average (0.2 m2.oC/W).
The experimental results of the study showed that the use of closed cavity wall reduced the average temperature of the inner surface of the wall during the day, and that the reduction was an average (0.45 oC) when compared with the conventional wall , as well as the use of closed cavity wall reduced the temperature difference range of the inner surface of the wall during the day, and that the
... Show MoreThe present research aims at identifying the relationship between intuitive thinking and mental alertness. The researcher used two tools: the intuitive thinking scale built by the researcher and consists of (40) paragraphs fall under four alternatives, while the second tool is the mental alertness scale consists of (70) paragraphs that the researcher built, and was verified psychometric properties of the two scales of honesty After the collection of information and statistical processing, the researcher reached the following results: 1. The results showed that the students of the third stage / Faculty of Education enjoy intuitive thinking. 2. The results showed that the students of the third stage / Faculty of Education enjoy mental alertne
... Show MoreTo detect the amount of rifampicin in bulk and medicinal dosage formulations, an accurate and costeffective UV spectrophotometric technique has been developed using the area under the peak to estimate the presence of rifampicin. This range of wavelengths (300–356 nm) was chosen. The method showed linearity in the 2–22 μg/mL range, with R2 being2 0.9996. The developed method’s linearity, detection limit, quantification limit, precision, repeatability, and accuracy were all statistically and experimentally validated. The suggested methodology can be used for routine quality control analysis of rifampicin in pure form and in capsule dosage form, as demonstrated by the satisfactory recovery percentage results. This study explores the str
... Show MoreTo detect the amount of Rifampicin in bulk and medicinal dosage formulations, an accurate, and cost-effective UV spectrophotometric technique has been developed using the area under the peak to estimate the presence of Rifampicin. This range of wavelengths (300–356) nm was chosen. The method showed linearity in the 2-22 μg/mL range, with R2 being 0.9996. The developed method' linearity, detection limit, quantification limit, precision, repeatability, and accuracy were all statistically and experimentally validated. The suggested methodology can be used for routine quality control analysis of Rifampicin in pure form and in capsule dosage form, as demonstrated by the satisfactory recovery percentage results. This study explores the struct
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