Al-Qadisiyah Journal for Engineering Sciences

Joint lockup due to dowel misalignment significantly affects joint and concrete pavement performance by causing joint distresses. The current paper presents an experimental study to assess the effectiveness of standard pull-out test in the evaluation of dowel misalignment effect on joint lockup of Jointed Plain Concrete Pavement (JPCP). The tests were conducted at two different ages of concrete ; 3 and 28 days. The results showed that the standard pull-out test or individually pulling of misaligned dowels cannot reflect the realistic defect of dowel misalignment. It also showed that the vertical orientation of misaligned dowel bars during the concrete casting reduces the pull-out load due to more distance from the exposure surface. Another observation was for all specimens, the pull-out load increases with an increase in concrete age.

The application of ground -penetrating radar (GPR) is addressed in this study, with the main application being the detection and classification of an underground target using GPR technology. This study focuses on the important task of GPR that needs to be done to improve the detection process, as well as ways to eliminate unwanted signals from the GPR image. The accuracy of detecting buried objects using GPR largely depends on the algorithms used, as the smart algorithm technology has proven to be the most accurate, effective, and cost-effective

The purpose of this paper is to study the disassembly task time in the maintenance and recycling context, knowing that only the reassembly task is needed in repairing operation. Dis/reassembly activities are delicate and need precise intervention due to the obligation of equipment refunctioning constraints. Time spent for dis/reassembling faulty components should be well-deducted and standardized. It is not always the case due to the various variant disassembly metrics and contexts. The Work Factor Method during dis/reassembly activities helps to develop the operational dis/reassembly time models. These models contribute to defining effective Time as far as operational dis/re-assembly activity is concerned and can help to optimize maintenance and recycling task planning.

The various graphical representations of planetary gear trains (PGTs), including basic assumptions and graph rules, are first reviewed in this paper. They revealed that they had close relationships. Their similarity has stimulated the development of a unified graphical representation. When there are multiple joints in a graph, it can be reconfigured without affecting the information contained in the graph. To accomplish this, a rooted graph in which a multiple joint represents either the housing of the mechanism and/or a transfer vertex of a multi-planet fundamental geared entity is employed.

Frees Space Optical (FSO) system employs space to transfer information between the transmitter and receiver using light. However, the single-beam Single Input Single Output (SISO) technology is well known for being subject to air attenuation induced by weather conditions, which decreases the performance link range and data quality. The proposed system in this research combines DWDM and MIMO approaches to address this issue. The research is based on Opti system simulations with various weather reductions in many FSO systems: the FSO-DWDM-SISO (FDS) scheme and the suggested FSO-Hybrid-DWDM-MIMO method (FHDM). FHDM technology has considerably enhanced connection distance, received power, scalability, and data speed. At a data rate of 500 Mb/s, an evaluation is made between the suggested method and the FDS concerning quality factors during varied weather reduction using different numbers of optical transmission beams. The results show that the FHDM system improves connection distance, received optical power, minimum bit error rate (BER), and highest quality factor significantly during various weather conditions.

In general, injecting grouts into small fractures, cavities, porous soil media, areas of water leakage, fixing cracks or defects in concrete, and filling spaces beneath metal bases or digging anchors are widely applied because of the great strength and workability of the cement in these materials. Furthermore, grout is employed effectively in the manufacturing of semi-flexible pavement mixes. The goal of this research is to develop a polymer-modified grout that can be used as a flowable grout for semi-flexible pavement mixes. The grout combination was made up of Ordinary Portland Cement (OPC), Acrylic emulsion (ACR), superplasticizer (SP), and water. ACR doses were 0.25, 0.5, 0.75, and 1.0 as a percent of OPC content. Flowability, compressive strength and flexural strength tests were conducted to characterize the produced grout, with different amounts of the specified components being employed for each test. The results revealed that the flow time rises slightly as the ACR increases. It is also shown that there is an ideal ACR dose based on compression strength. Where in most cases, the upgrading of the produced grouts was validated by a flexural strength test. In a conclusion, polymer-modified grout worthily adds acceptable features to grout mechanical characteristics if the constituents of the grout are optimized.