Journal of Engineering and Sustainable Development (JEASD)

In this paper a method for computing the lateral deflection and the failure load for the slender composite columns of the type of concrete encased steel sections which is subjected to axial load with equal end eccentricities in addition to uniform lateral load is described. A computer program is used to calculate the deflection at the center of the column, hence it represents the maximum value, that corresponds to a specified properties of cross section(dimensions and strength of materials), length, and loading condition (axial load, eccentricity and uniform distributed lateral load which is taken as a proportion of the axial load). Relationships between the failure lateral load/axial load ratio and the ratio of steal area to the concrete area of the composite section for different end eccentricities are shown. The relation between the central deflection and uniform distributed load for different axial loads values and end eccentricities are shown too.

Multi-Carrier Modulation (MCM) is an attractive technique for copper wire access technology in high-performance communication networks (e.g. Asymmetric and Very-high-rate Digital Subscriber Line). In digital implementations of MCM, subcarrier generation and data modulation are accomplished digitally using orthogonal transformations of data blocks called Discrete Multi-Tone (DMT). These implementations are efficient with regard to bandwidth utilization and transceiver complexity. In this article, a variant high-performance digital MCM was used, the Discrete Wavelet Multi-Tone (DWMT) transmission. The standard asymmetric digital subscriber
line modems use DMT line code and are able to deliver up to 8 Mbps.

This work is directed toward the development of the corrosion resistance of the steel pipeline structures utilizing concrete coating using the cathodic protection technique to protect the structure of the coated steel pipeline structure. It deals with the matter of steel structures upon the survey periods, electrochemical dormant period because of the continuous cathodic prevention and the activation corrosion upon interruption period of this cathodic prevention and treatment this case of corrosion using the cathodic protection technique. The initial free corrosion potential (Ecorr) upon intermittently intervals and the corrosion rate measurement of the specimens using full polarization curve (Tafel Method) has been observed. The results clearly indicated that to achieve efficient design of a cathodic protection, the protected area should be divided into discrete electrochemical areas depending on the electrical resistance and steel potential to prevent the over-protection in the low electrical resistance areas when applying the designing criteria on the high electrical resistance areas. Furthermore, the results indicate that the absolute value of protection potential does not adequately describe the electrochemical changes undergone by the polarized coated steel pipe.

In this paper, the effect of previous heating on load-slip relationship in modified
push-out test is studied. Specimens of concrete slab with connectors (connector embedded
in the concrete slab) were put in an oven of high heating for at least one hour after
reaching a specified temperature (300~700) oC. Due to these high temperatures, the
compressive strength of concrete was reduced and cracks were seen on the surface of
concrete. The slip was increased and the stiffness of the connector was decreased
significantly. It is concluded that the effect of previous heating on the connector stiffness is
greater than its effect on the compressive strength of concrete due to presence of cracks in
concrete after heating to high temperatures.

In this paper the principles of wideband microwave amplifier will be highlighted. Special attention goes to the design methodology of high-gain cascaded single-stage distributed amplifiers (CSSDA). Alternation to the basic design including the use of “cascode” gain cells is then discussed. This is a new technique for enhancing the bandwidth of the amplifier. The final design is implemented using microwave office program. A four-stage CSSDA with and without cascode cells were tested in order to demonstrate the validity of the proposed method.

Inflatable dams are flexible cylindrical inflatable and deflatable structures made of rubberized material attached to a rigid base and inflatable by air, water, or a combination of air/water. The interest in inflatable dams is increasing because of the ease of placement and construction. Behavior of air or water inflated dams is physically studied and analyzed under different conditions of internal pressure, upstream and downstream heads of water. Experimental data obtained on laboratory test facility for with air and/or water
inflated dams are presented and compared with the theoretical results based on a developed computer program describing dam height, cross sectional profiles and dam cross-sectional area. Good agreement was obtained between theory and experiment results.

Serial concatenated convolutional coding with iterative decoding is examined for data transmission over the downlink of a WCDMA system employing BPSK modulation and coherent Rake receiver. Performance of serial concatenated convolutional coding is studied in a frequency selective Rayleigh fading channel. The new type of external interleaver which is called Dithered Golden section Interleaver (DGI) is used The effect of correlated fading on the performance of the proposed system is investigated by considering external block interleaver delays of 10 ms at mobile speeds 5 and 100 km/h. Simulation results show that the employing this type of interleaver is outperforming at high signal to noise ratios the structured interleaver (Block, circular …etc).

Four specimens of the zinc eutectic Composition (95% Zn + 5% AL) were prepared by casting method, the first specimen was air cooled and the second was water cooled. They revealed irregular Lamellar-eutectic microstructures (L.E.M.). The third specimen was sliced into many Samples with constant thickness, but with variable solidification velocity by using a movable tube furnace, which resulted in a regular (L.E.M), this process revealed that: (n) in the equation (λnV=K) was equal to (2.2). However, our finding was different from those obtained by TILLER, which stated that (n=2) But this result falls into an agreement with the modification of LESOULT, the result was in good agreement with the experimental data which governed by relationship.