The fashion industry incorporates innovative technologies to realise new products and designs. Tailored fashion product development very soon tested 3D printing techniques, overcoming many challenging issues. This study investigates the effects of three variables during fused filament fabrication on surface roughness of buttons used for clothing products. First, parameter design is applied to select the experimental area and parameters levels, i.e., the extruding temperature, layer thickness and printing speed are tested following the Box-Behnken experimental design. Then a second-order model is used as a response surface to optimise the parameters and evaluated using contour plots and ANOVA analysis. The values of 230°C extrusion temperature, 0.2 mm layer thickness and 45 mm/s printing speed optimise the average roughness resulting in about three μm for the upper surface.
The impact of increased sintering rate on the dimensional accuracy, surface topology, and tensile properties of selective laser-sintered polyamide (PA 2200) flat samples was investigated. The sintering rate is significantly influenced by the scan speed and the scan spacing. It was observed that different dimensional accuracies were achieved depending on the measurement direction. The surface topology changed depending on which of the two parameters was increased. Besides, it could be observed that an increase in the sintering rate did not result in a change in yield and tensile strength but in a decrease of 37% in elongation at break. Post-treated samples using different grinding processes were bonded and subjected to a tensile test. It was found that increasing the surface roughness up to an optimum value improved the tensile strength of the bonded joint. Furthermore, surface activation enhanced the tensile strength of the joint by up to 28%.
This paper discusses impedance spectroscopy as a novel and effective method of characterising electrical materials and probing the dynamics of charge carriers at the interfacial layers of dielectrics. Here, an experiment is carried out to characterise the ionic conductivity (which infers resistivity) of two lithium-borate glass samples as a function of temperature, by means of impedance spectroscopy. The experiment compares or fits the impedance data to an equivalent circuit, which is a model of the underlying physical processes under investigation, and discusses the analogies between circuit elements and the processes. Analyses of the results show how the impedance of lithium-borate glass varies with temperature, between 240°C and 320°C. Moreover, this paper provides a conceptual foundation for introducing the experiment into school curricula.
Data mining and machine learning tools and approaches have been extensively used and practiced in bioinformatics with the purpose of analysing biomedical datasets. In this paper, we have chosen 'RapidMiner Studio' as a platform to create/generate 'decision tree models', which are obtained from a medical dataset. In research, 'decision trees' are considered as one of the most popular supervised (machine) learning techniques, which, as an instance can be effectively used for prediction of specific indicators/attributes affecting a disease. In general, this paper is divided into two main parts. In the first part of the study, an existing medical dataset with known label values (so-called, a training dataset) is used to identify and discover the hidden patterns. In the second part of the study, the generated/resulting patterns are used for making predictions. The results of the study provide groundwork for further and future studies.
Space launch operations at Kennedy Space Center and Cape Canaveral Space Force Station (KSC/CCSFS) are complicated by unique requirements for near-real time determination of risk from lightning. Weather sensor networks for lightning forecasting produce data that are noisy, high volume, and high frequency time series for which traditional forecasting methods are often ill-suited. Current approaches result in significant residual uncertainties and consequentially may result in forecasting operational policies that are excessively conservative or inefficient. This work first proposes a forecasting methodology using wavelet decomposition of chaotic weather sensor time series and semiparametric single-index models to mitigate the chaotic signal and any possible distributional misspecification. Then, a screening experiment with augmentations is used to demonstrate how to explore the complex factor space of model parameters, guiding decisions regarding model formulation and gaining insight for follow-on research. Results indicate a promising technique for operationally relevant lightning prediction from chaotic sensor measurements.
Nanocoolant minimum quantity lubrication is economical, sustainable, and an environment-friendly technique of coolant flow for machining compared to flood lubrication. In the present experimental study, the modelling and optimisation of nanocoolant minimum quantity lubrication process are carried out for improving the grinding performance of EN 31 hardened steel. The optimised value of input process parameters such as table speed, depth of cut, coolant flow rate, dressing depth, and aluminium oxide nanocoolant concentrations obtained from the Jaya algorithm is used for finding the grinding performance in terms of cutting forces, surface roughness, and material removal rate. The experiments were conducted by response surface methodology using Minitab 17 statistical software. The optimisation of process parameters is carried out for single and multi-objective responses. The results show that the nanocoolant minimum quantity lubrication process improves the grinding performance significantly using optimised values at 0.30 volume % nanocoolant concentration.
Classical simplex designs allow the assessment of n factors in n + 1 experimental runs. However, the classical design specifies levels, intervals, and coded values that differ from factor to factor, and this is experimentally inconvenient. This research note presents the means to rotate the simplex to orient all factors to the same three coded values { p, q, r}, or to ±1 if n = 2J - 1, where J is an integer. Such rotations render the simplex design much more convenient for experimental work. This note also presents a means for generating two-value simplex matrices that may be viewed as non-orthogonal fractions of two-level factorial designs.
