Problem-solving is an iterative process that requires brainstorming, analysis of the problem, development and testing of solutions. It relies on under-standing what is known and what is unknown about the problem. That knowledge of the knowns and unknowns is called metacognition. Today’s engineers must understand their own metacognition and that of other team members to derive the best solutions for engineering problems given the different constraints. Engineers working in design and manufacturing fields confront challenges due to a lack of important metacognitive understanding of their own and their team’s problem-solving skills. This research suggests measuring metacognition within teams by using manufacturing simulations with virtual reality and eye tracking
In this paper, a novel vehicle routing algorithm will be presented. Proposed method will be based on “time windows-based clustering” and “location-based clustering”, applied in reversable consecutive order. The method partitions and models the solution space with machine learning technologies, resulting in a better performance for time window and geospatial clustering calculations. Routing process, on the other hand, will be built upon already present open source tools, giving it usability, applicability, manageability, and integration perspectives. The process combines “cluster+cluster+route” units with post process enhancements. Previous works on location-based clustering are proved to be successful, albeit with some disadvantages. On the other hand, routing algorithms have mostly implemented time window calculations as second-class citizens. In this method, time window is a major ingredient of the modelling process. This paper will also differs from some other combinatoric methods used in literature. A history and general description of used methods and tools will also be provided. It is shown that the algorithm can generate good results, some of which are the best values in the recorded literature so far. The method is applied on a big data platform. Horizontal scaling and distributed processing capabilities with the state-of-the-art tooling on such systems are also described.
This of article is devoted to solving the problem of determining the actual mechanism of corrosion caused by the influence of corrosive environment with high pressures and temperatures on the tubing pipe metal, during high depth condensate fields development, with a high content of hydrogen sulfide and carbon dioxide in the fluid. The of results of the actual state evaluation of tubing pipe specimens are presented, the causes and nature of the corrosion damages and the mechanisms of their progress in the given conditions are identified. In particular, the of results of visual and instrumental investigation shows, that corrosion of the tubing surface has local (zone) nature; corrosion processes occurs as on interior as well on exterior tubing surface, whereby interior surface has the presence of corrosion deposits in local zones and also pitch zones, and exterior surface corrosion is present only by pitch corrosion. The local corrosion on the tubing surface is caused by carbon dioxide carrion. The main impact factor is the presence in gas-liquid mixture the molecules of СО 2 and Н 2 СО 3 and ions НСО 3 - and HСО 3 2- , as a result of carbon dioxide gas dissolving, which activate the environment corrosive aggressiveness.
This paper examines the experimental study on a line axis concentrating solar energy collector for water heating. The system considered consists of cylindrical solar radiation concentrator with a black coated tubular absorber positioned along its axis. A cold water tank is placed above the collector and a hot water tank positioned below it such that fluid flows in and out of the set up. Solar radiation absorber inlet header is connected to the cold water tank while its outlet header is connected to the hot water tank. These major components are supported by angle iron raised at a distance from the ground that depends on the location and function. Valves are used at strategic points on the connecting pipe lines to isolate the flow of water. When water is poured into the cold water chamber, and the control valve turned on, the water flows under gravity into the receiver/absorber tube. At the absorber section, heat is transferred from the steel tube to the circulating water and is consequently heated. The heated water, then flows into the returning tube against gravity, thereby restricting the heated water from flowing into the storage tank. At this stage, thermo-siphoning effect comes into play. As the temperature of the water increases, its density reduces while the mass remains constant in order to balance the effect of the reduction in density. Thus, there is a resultant increase in volume which consequently pushes the water level further along the returning pipe. Further increase in temperature reduces the water density and increases the volume of the water, thereby causing the heated water to flow into the insulated tank. Several experimental tests were carried out under meteorological condition at the Federal University of Technology Owerri, Nigeria at three different mass flow rates of 0.001kg/s, 0.002kg/s and 0.003kg/s. The solar water heater was tested while oriented in the East–West and North –South directions in order to determine the effects of orientation on the performance. Results obtained showed that a maximum temperature of 69.5°C, corresponding to 34.5°C increase in water temperature and a maximum instantaneous efficiency of 51.01% is possible. The aim of the study is to design a cheaper solar energy system capable of reducing energy bill within the developing countries of the world.
Vegetable are considered as the leafy outgrowth of plants shoot used as food. These include those plants or plant part used in making soup or served as an integral part of main meal they are sources of nutrients, vitamins and minerals. Drying is a cheap means of preserving vegetables because they are prone to fungi contamination. The assessment of aflatoxigenic fungi associated with dried vegetables (Baobab, Red chilli pepper, Okro and Tomatoes) from selected markets within Kaduna metropolis were investigated. A total of forty (40) samples (ten samples each) of the dried vegetables were analyzed for fungi and total aflatoxin. Fungi were identified and characterized using the conventional and Molecular technique and Total Aflatoxin were identified using Enzyme linked immune-sorbent assay (ELISA). The fungi identified were Aspergillus flavus and Aspergillus niger. The result of the total aflatoxin revealed that Baobab from Sabo (SB 001) had the highest aflatoxin of 31.6μg/kg while Baobab from Barnawa (BRW 001), with aflatoxin content of 18.80μg/kg. Baobab from Tudun wada (TW 001) with aflatoxin content of 15.00μg/kg, Baobab from Malali (MLL 001) had aflatoxin content of 12.10μg/kg is higher while Baobab from Central Market had aflatoxin of 1.60μg/kg. The vegetable with the highest aflatoxin content is Baobab from Sabo (SB 001) had aflatoxin content of 31.6μg/kg, while Okra from kamazou (KMZ 003) with aflatoxin content of 27.00μg/kg and Red Chilli Pepper from Malali (MLL004) had aflatoxin content of 26.40μg/kg, Tomatoes from Malali (MLL 002) had the lowest aflatoxin content of 6.50μg /kg. These result can serve as baseline for enacting laws and observing the critical control point as the ingestion of such mycotoxins contaminated vegetables have enormous health significance. Because these toxins are capable of causing diseases in man and animals.
Site selection is one of the main principles of the passive defense. A multiple objective and nonlinear programming formulation which considers the principles of passive defense site selection according to both qualitative and quantitative aspects is proposed in this paper. The aim is to reduce the site selection costs while the security of network formed by the facilities is maximized, and to reduce the costs of the network after being attacked. To solve the proposed model, a GA-TOPSIS method is proposed.
The use of vehicles in Pakistan is increasing day-by-day because of which disposal of solid waste to the landfills of used tyres is a serious issue to be solved for Pakistan EPA. Currently this industry is facing many challenges due to lack of support from government for the recycling and reuse of waste tyre by products but manually a large quantity of high strength steel fibers are being extracted from waste tyres, the dominant use of this tyre-derived fiber is a scrap steel to manufacture new iron or steel. This research study is focusing on the use of steel fibers extracted from waste tyres in concrete with different proportions to produce a concrete more strong than ordinary concrete (specially as a member like Beam) economical and cost effective. Different concrete specimens were fabricated and tested in uniaxial compression testing machine to find compression and splitting Beams for the Flexural Strength. The steel fibers were substituted into the concrete by dry weight of mix with 0%, 0.5%, 1%, 1.5%, 2% and 2.5%. Result shows that the flexural strength of concrete with 2.5% fibers improved up to 74%.
Evaluation possibility of a low quality Egyptian oil shale from Wadii El-Nakhil, Red sea region as an alternative clean fuel by flotation technique was investigated. Oil shale sample was characterized using XRD and FTIR analyses to determine its mineral content and surface characteristics. XRD analysis showed that the non-clay minerals present in the oil shale sample include; quartz, siderite, apatite, anhydrite and calcite. The clay mineral is mainly represented by kaolinite while the organic matter is 30%. The effects of frother and collector dosages and pulp Ph on the flotation performance were investigated using kerosene as a collector. The pine oil or MIBC were used as frothing agents. By using 5g/kg kerosene as a collector and 9g/kg of MIBC as a frother at pH 9, a kerogen of 38% with recovery of 88.5% was obtained from oil shale sample of 28%.
Overall equipment efficiency (OEE) measures the ratio of how much of a product or part is being made defect-free versus how much could be made according to the equipment’s design. A machine or process that has an OEE of 100 percent is producing at its maximum designed capacity with zero defects. Three metrics – availability, performance and quality – make up OEE. When real output is lower than expected, practitioners can find opportunities for improvement in all three of these factors and take actions that maximize the current process capabilities, fix problems and improve productivity.
