The Investigation of an Efficient and Effective Proactive Pipeline Integrity System

In this paper, we propose the investigation of an efficient and effective proactive pipeline integrity system that uses multi-sensors for monitoring and inspection of the pipeline. Although the focus is on the pipeline, the methodologies will also be applicable for other systems including other energy infrastructure elements. The investigation focuses on the integration of multi-sources of data as well as multi-types of data for the same location (section) of the pipeline. The data include imaging, acoustic signals, electromagnetic flux system, and others. Moreover, the data could be obtained using continuous monitoring of the pipeline sections or through time intervals. In both cases, the data may also include censored observations. We develop several approaches to filter the data for noise and identify outliers, integrate the data streams into one degradation path and determine the optimum time to maintain or replace the pipeline sections being monitored. It will utilize extensive mathematical modeling for condition-based maintenance and repair, which will be developed by the investigators of this proposal. Following the suggestions of one of the reviewers of the last year's submission, we plan to validate and modify the model using standard or artificially developed defects such as corrosion, cracks, stress cracking, etc. to understand the output of the proposed methodology and validate the models accordingly

Safety performance of school buses in the State of Qatar

School buses and minibuses are one of the major modes of traveling for students in the state of Qatar. Many studies pointed to the fact that school buses travelling are safer for students than walking or car riding (Bolte, et al., 2000; Hinch, et al., 2002). For that reason, safety measures and performance of school buses in the State of Qatar should be studied and evaluated carefully and wisely. The project aims were done through merged qualitative and quantitative methods. Initially a safety checklist was constructed for school buses and a comprehensive schools map to evaluate of the current safety measures in school buses and to understand the conditions around the surrounding areas like the location of the bus stops and the availability of signage. Then, the second step focuses on conducting a survey for school bus drivers, school bus guides, students, and parents. Finally, the third steps compares between the school bus safety strategies followed in the State of Qatar and the strategies followed in other high income countries. The results of the field visits revealed many very important statistics for all surveys on the safety of school bus and the surrounding areas as well as the behavior of students and drivers. The results revealed that most of the parents are not happy with the safety while loading and unloading and with the safety procedures. In addition, 43% of school bus users didn't attend any training or workshops about the safety procedures in school bus. References: [1] Bolte, K. et al., 2000. Simulations of Large School Bus Crashes. [Online] Available at: http://papers.sae.org/2000-01-0469/ [Accessed 10 october 2014]. [2] Hinch, J. et al., 2002. School Bus Safety: Crashworthiness Research, Washington: National Highway Traffic Safety Administration.Qscienc

Influence of Micron-Ti and Nano-Cu Additions on the Microstructure and Mechanical Properties of Pure Magnesium

In this study, metallic elements that have limited/negligible solubility in pure magnesium (Mg) were incorporated in Mg using the disintegrated melt deposition technique. The metallic elements added include: (i) micron sized titanium (Ti) particulates with negligible solubility; (ii) nano sized copper (Cu) particulates with limited solubility; and (iii) the combination of micro-Ti and nano-Cu. The combined metallic addition (Ti + Cu) was carried out with and without preprocessing by ball-milling. The microstructure and mechanical properties of the developed Mg-materials were investigated. Microstructure observation revealed grain refinement due to the individual and combined presence of hard metallic particulates. The mechanical properties evaluation revealed a significant improvement in microhardness, tensile and compressive strengths. Individual additions of Ti and Cu resulted in Mg-Ti composite and Mg-Cu alloy respectively, and their mechanical properties were influenced by the inherent properties of the particulates and the resulting second phases, if any. In the case of combined addition, the significant improvement in properties were observed in Mg-(Ti + Cu)BM composite containing ball milled (Ti + Cu) particulates, when compared to direct addition of Ti and Cu particulates. The change in particle morphology, formation of Ti3Cu intermetallic and good interfacial bonding with the matrix achieved due to preprocessing, contributed to its superior strength and ductility, in case of Mg-(Ti + Cu)BM composite. The best combination of hardness, tensile and compressive behavior was exhibited by Mg-(Ti + Cu)BM composite formulation

Microstructure and Mechanical Properties of Mg-5Nb Metal-Metal Composite Reinforced with Nano SiC Ceramic Particles

In this work, a Mg-5Nb metal–metal composite was reinforced with nano SiC (SiCn) ceramic reinforcement of varying volume fractions, using the disintegrated melt deposition technique. The extruded Mg-5Nb-SiCn composites were characterized for their microstructure and mechanical properties. Based on the results obtained, it was observed that the volume fraction of nano-SiC reinforcement played an important role in determining the grain size and improving the mechanical properties. A comparison of properties with those of pure Mg and Mg-5Nb composite showed that while the improvement in hardness occurred at all volume fractions, a minimum volume fraction of ~0.27% SiCn was required to increase the tensile and compressive strengths. The observed mechanical response of the composites were investigated in terms of the effect of SiCn volume fraction, processing, distribution of metallic and ceramic reinforcements and the inherent properties of the matrix and reinforcements. The influences of these factors on the mechanical behavior of the composites are understood based on the structure–property relationship

Reliability estimation of load sharing capacity-c-out-of-n pairs:G Balanced system

In many cases, systems are required to provide a specified capacity such as the case of power distribution system. A system fails when its capacity does not meet the required minimum capacity. In this paper, we investigate reliability estimation of capacity-c-out-of-n pairs:G Balanced systems which consist of units in a balanced spatial configuration. When one of the units fails its load is shared among the remaining units. The load shared by each operating unit affects its reliability and hence the system reliability. We incorporate load sharing effect on reliability of individual units into the estimation of system reliability. Higher load sharing has adverse effect on system reliability as demonstrated using a numerical example.Scopu

In situ strengthening of thin-wall structures using pressurized foam

A simple and effective in situ method for strengthening or healing thin-wall structures is presented. In this method, a liquid-state gap-sealing foam is injected within the enclosed spaces of a structure. After injection it expands to fill and pressurize the cavities, then solidifies in few hours. The stiff pressurized foam enhances load carrying capacity both by supporting part of the load, and by retarding the buckling of thin-wall structural components. A simple demonstration of the proposed technique is provided by load-testing thin-wall beverage cans, and also both intact and damaged aluminum honeycomb, filled with commercially available gap-sealing polyurethane foam. By adding foam, the structures' peak load and energy absorption were significantly enhanced. The injected foam partially restored the original undeformed shape during unloading, highlighting the potential advantage to apply this method for multiple-use energy absorbing components.Qatar National Research Foundation (QNRF) Award Number NPRP 09-145-2-061Scopu

Safety performance of school buses in the State of Qatar

School buses and minibuses are one of the major modes of traveling for students in the state of Qatar. Many studies pointed to the fact that school buses travelling are safer for students than walking or car riding (Bolte, et al., 2000; Hinch, et al., 2002). For that reason, safety measures and performance of school buses in the State of Qatar should be studied and evaluated carefully and wisely. The project aims were done through merged qualitative and quantitative methods. Initially a safety checklist was constructed for school buses and a comprehensive schools map to evaluate of the current safety measures in school buses and to understand the conditions around the surrounding areas like the location of the bus stops and the availability of signage. Then, the second step focuses on conducting a survey for school bus drivers, school bus guides, students, and parents. Finally, the third steps compares between the school bus safety strategies followed in the State of Qatar and the strategies followed in other high income countries. The results of the field visits revealed many very important statistics for all surveys on the safety of school bus and the surrounding areas as well as the behavior of students and drivers. The results revealed that most of the parents are not happy with the safety while loading and unloading and with the safety procedures. In addition, 43% of school bus users didn't attend any training or workshops about the safety procedures in school bus. References: [1] Bolte, K. et al., 2000. Simulations of Large School Bus Crashes. [Online] Available at: http://papers.sae.org/2000-01-0469/ [Accessed 10 october 2014]. [2] Hinch, J. et al., 2002. School Bus Safety: Crashworthiness Research, Washington: National Highway Traffic Safety Administration.Qscienc

The effect of graphene on the activation energy of grain growth for the nanocrystalline thermoelectric n-type Bi2Te2.7Se0.3

Even though bismuth telluride is frequently produced by mechanical alloying for thermoelectric materials, no data has been published addressing the thermal behavior and activation energy of the milled n-type Bi2Te2.7Se0.3 powders. This paper studies the activation energy of grain growth for the nanocrystalline n-type Bi2Te2.7Se0.3 and two graphene-Bi2Te2.7Se0.3 composites with different graphene concentrations (0.05 and 0.5 wt.%). Grain size and structural analyses of these samples have been carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal stability of the three samples is investigated by incorporating differential scanning calorimetry data with the Kissinger model. The activation energy of the pristine Bi2Te2.7Se0.3 alloy is found to be 268 kJ/mol. For the composite samples, a lower graphene weight percentage (0.05 wt.%) increased the activation energy to 270 kJ/mol. In contrast, higher amounts of graphene (0.5 wt.%) reduced the activation energy significantly to 254 kJ/mol. The observed effect is found to be directly related to graphene’s exfoliation in the bismuth telluride matrix. These results offer a better understanding of the thermal behavior of the nanocrystalline pristine n-type Bi2Te2.7Se0.3 and the influence of graphene nanofiller on the thermal stability of the bismuth telluride nanocomposites.Other Information Published in: Emergent Materials License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s42247-022-00416-5</p