Robust real-time detection of multi-color markers on a cell phone

We describe a fast algorithm to detect special multi-color markers with a camera cell phone. These color markers can be used for environmental labeling, for example, as a wayfinding aid for persons with visual impairment. Using a cascade of elemental detectors, robust detection is achieved at an extremely low computational cost. We also introduce a strategy to select surfaces for the marker that ensure very low specular reflection, thus facilitating color-based recognition.     

Novel nanofiber-based triple-layer proton exchange membranes for fuel cell applications

New types of triple-layer membranes were fabricated using multi-step impregnation of Nafion in electrospun webs based on bead-free nanofibers of sulfonated poly(ether sulfone) (SPES). The results showed that the fabricated nanofiber-filled membrane owing to its reduced methanol permeability as well as sufficient proton conductivity and membrane selectivity can be used as a promising proton exchange membrane for direct methanol fuel cell (DMFC) applications. The single cell DMFC performance results revealed that the SPES nanofiber-based triple-layer membranes have higher electrochemical performance than commercial Nafion membranes.     

(DP)SM: A dynamic approach to resouce constraint project scheduling

The purpose of this paper is twofold, first to introduce and evaluate a dynamic priority scheduling model developed in this research for solving the resource constraint project scheduling problem, second to introduce an improvement made upon the first model by cross breeding Dynamic Programming with the Dynamic Priority Scheduling Method (DPSM). The second model called Dynamic Priority Dynamic Programming Scheduling Method [(DP)²SM] aims at optimising the staged resource allocation decisions in DPSM. DPSM divides a project into phases (cycles) the length of which depend on the duration of the project and the period of clock cycle selected. The scheduling process starts by allocating resources to the first phase/cycle using a variety of policies, then the best schedule is selected based on an objective function. The process continues till all the activities are scheduled. In DPSM the interaction between phases is ignored while the decisions of each phase or cycle will affect all the remaining phases. Using (DP)² SM it may be possible to improve the quality of a schedule and reduce the duration of a project by optimising the overall project schedule.     

Introducing Climax: A novel strategy to a tri-wheel spiral robot

This paper describes a prototype and analytical studies of a tri-wheel spiral mobile robot. The robot can reach any desired point with a sequence of rotational movements. The robot has a simple actuation mechanism, consisting of three wheels mounted on a platform with axes fixed in 120° and a motor connected to each. Our approach introduces several new features such as simple repeated sequence of commands for steering and spiral motion, versus direct movement to target. The mathematical model of the robot is discussed, and a steering method is developed to achieve full motion capabilities. For a number of missions, it is shown experimentally that the proposed motion planning agrees well with the results.     

Pd nanoparticle loaded TiO<Subscript>2</Subscript> semiconductor for photocatalytic degradation of Paraoxon pesticide under visible-light irradiation

Overuse of the organophosphorus pesticides such as Paraoxon in agriculture industry has raised significant threats to the environment by contamination of soils and groundwaters. Therefore, extensive studies have been carried out to develop an effective method for removing of these poisonous pollutants from contaminated resources. In the current study, Pd nanoparticle loaded TiO₂ nanocomposites with different weight percentages of Pd were prepared via a facile photoreduction method and for the first time, were used for photocatalytic degradation of Paraoxon under visible-light irradiation. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy techniques. In these nanocomposites, the presence of Pd nanoparticles enhances the photocatalytic activity of TiO₂ by their surface plasmon resonance effect and also by narrowing the band gap energy of TiO₂. The results of photocatalytic activity measurements indicate that the nanocomposite with 0.8 wt% content of Pd (PT0.8) has the best photocatalytic activity. The result of total organic carbon test shows that Paraoxon was completely mineralized by PT0.8 photocatalyst after 120 min, under visible-light irradiation.     

Graphene‐Coated Spandex Sensors Embedded into Silicone Sheath for Composites Health Monitoring and Wearable Applications

This study presents a low‐cost, tunable, and stretchable sensor fabricated based on spandex (SpX) yarns coated with graphene nanoplatelets (GnP) through a dip‐coating process. The SpX/GnP is wrapped into a stretchable silicone rubber (SR) sheath to protect the conductive layer against harsh conditions, which allows for fabricating washable wearable sensors. Dip‐coating parameters are optimized to obtain the maximum GnP coating rate. The covering sheath is tailored to achieve high stretchability beyond the sensing limit of 104% for SpX/GnP/SR sensors. Adjustable sensitivity is attained by manipulating SpX immersion times broadening its application for a wide range of strains: Gauge factors as high as two orders of magnitude are achieved at tensile strains greater than ≈40%. The fabricated sensors are tested for two applications: First, the SpX/GnP sensors are integrated into composite fabrics (with no negative impact on the structural integrity of the part) for screening the yarn displacements, resin flow, solidification during the hot press forming process, and structural health monitoring under mechanical loads with minimal cross‐sensitivity to temperature/humidity. Second, the capability of SpX/GnP/SP sensors in detection of a wide range of bodily motions (from the joint motion to arterial blood pressure) is demonstrated.     

Fuzzy Expert System to Assess Corrosion of Cast/Ductile Iron Pipes from Backfill Properties

Abstract:  Several factors may contribute to the structural failure of cast and ductile iron water mains, the most important of which is considered to be corrosion. The ANSI/AWWA C105/A21.5-99 10-point scoring (10-P) method is commonly used to predict the corrosivity potential of a given soil sample using certain soil properties. The 10-P and other scoring methods use binary logic to classify the soil as either corrosive or noncorrosive . Fuzzy logic extends binary logic in this context as it recognizes the real world phenomena using a certain degree of membership between 0 and 1. This article presents a fuzzy logic expert system capable of predicting the deterioration of cast and ductile iron water mains based on surrounding soil properties. The proposed model consists of two modules: a knowledge base and an inference mechanism. The knowledge base provides information for better decision making and is developed in a two-tier fuzzy modeling process. First in direct approach, the expert knowledge generates a subjective model to describe the characteristics of the system using fuzzy linguistic variables. Later in system identification, the field data are used to develop an objective model, which is eventually used in conjunction with the subjective model to provide a more reliable knowledge base for the expert system. The inference mechanism uses fuzzy approximate reasoning methods to process the encoded information of the knowledge base.     

Preparation and characterization of nanocomposite membranes made of poly(2,6-dimethyl-1,4-phenylene oxide) and montmorillonite for direct methanol fuel cells

Partially sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (sulfonated PPO) with various degrees of sulfonation were prepared. The solutions were mixed with organically modified montmorillonite (MMT) to prepare membranes by solvent casting. By increasing the sulfonation degree up to 40% for membranes without MMT, ion exchange capacity, water uptake and proton conductivity reached 2.59 mequiv. g⁻¹, 21% and 0.0182 S cm⁻¹, respectively. The Fourier transfer infrared (FTIR) analysis of sulfonated membranes revealed absorption bands at 1060 and 1100–1300 cm⁻¹ for sulfur–oxygen SO bonds. X-ray diffraction analysis showed the exfoliated structure of clay in polymeric matrices. A sulfonated PPO/MMT membrane with 27% sulfonation and 2.0 wt% MMT loading showed a membrane selectivity of approximately 63,500 compared to 40,500 for Nafion^® 117, and also a higher power density (125 mW cm⁻²) than Nafion^® 117 (108 mW cm⁻²) for single cell DMFC in a 5 M methanol feed.     

High-velocity impact loading in honeycomb sandwich panels reinforced with polymer foam: a numerical approach study

The employment of lightweight structures is one of the most important goals in various industries. The lightweight sandwich panel is an excellent energy absorber and also a perfect way for decreasing the risk of impact. In this paper, a numerical study of high-velocity impact on honeycomb sandwich panels reinforced with polymer foam was performed. The results of numerical simulation are compared with the experimental findings. The numerical modeling of high-velocity penetration process was carried out using nonlinear explicit finite-element code, LS-DYNA. The aluminum honeycomb structure, unfilled honeycomb sandwich panel, and the sandwich panels filled with three types of polyurethane foam (foam 1: 56.94, foam 2: 108.65, and foam 3: 137.13 kg/m³) were investigated to demonstrate damage modes, ballistic limit velocity, absorbed energy, and specific energy absorption (SEA) capacity. The numerical ballistic limit velocity of sandwich panels, filled with three types of foam, was more than that of a bare honeycomb core and unfilled sandwich panel. In addition, the numerical results showed that the sandwich panel filled with the highest density foam could increase the strength of sandwich panel and the numerical specific energy absorption of this structure was 23% more than that of unfilled. Finally, the numerical results were in good agreement with experimental findings.

     

Integrated Decision Support System for Prognostic and Diagnostic Analyses of Water Distribution System Failures

This paper presents an innovative decision support system (DSS) for prognostic and diagnostic analyses of water distribution system (WDS) failures. The framework of the DSS is based on four novel models developed and published by the authors of this paper. The four models include reliability assessment model, leakage potential model, leakage detection model, and water quality failure potential model. Information obtained from these models together with external information such as customer complaints, lab test results (if any), and historical information are integrated using Dempster-Shafer (D-S) theory to evaluate prognostic and diagnostic capabilities of the DSS. The prognostic capabilities of the DSS provide hydraulic and water quality states of a WDS whereas the diagnostic capabilities of the DSS help to identify the failure location with minimal time after the occurrence and will help to reduce false positive and false negative predictions. The framework has ‘unique’ capacity to bring the modeling information (hydraulic and Quality), consumer complaints, historical failure data, and laboratory test information under a single platform to perform a prognostic and diagnostic investigation of WDS failures (hydraulic and Quality). The proof of concept of the DSS has been demonstrated using data used in published four articles. The outcomes of this research widely addressed the uncertainties associated with WDS which improves the efficiency and effectiveness of diagnosis and prognosis analyses of WDS. It is expected that the developed integrated framework will help municipalities to make informed decisions to increase the safety, reliability and the security of public health.