Wastewater Plant Reliability Prediction Using the Machine Learning Classification Algorithms

One way to optimize wastewater treatment system infrastructure, its operations, monitoring, maintenance and management is through development of smart forecasting, monitoring and failure prediction systems using machine learning modeling. The aim of this paper was to develop a model that was able to predict a water pump failure based on the asymmetrical type of data obtained from sensors such as water levels, capacity, current and flow values. Several machine learning classification algorithms were used for predicting water pump failure. Using the classification algorithms, it was possible to make predictions of future values with a simple input of current values, as well as predicting probabilities of each sample belonging to each class. In order to build a prediction model, an asymmetrical type dataset containing the aforementioned variables was used.

Improving the Electrochemical Performance and Stability of Polypyrrole by Polymerizing Ionic Liquids

Polypyrrole (PPy) based electroactive materials are important building blocks for the development of flexible electronics, bio-sensors and actuator devices. As the properties and behavior of PPy depends strongly on the operating environment—electrolyte, solvent, etc., it is desirable to plant immobile ionic species into PPy films to ensure stable response. A premade ionic polymer is not optimal in many cases, as it enforces its own structure on the conducting polymer, therefore, polymerization during fabrication is preferred. Pyrrole (Py) was electropolymerized at low temperature together with a polymerizable ionic liquid (PIL) monomer in a one-step polymerization, to form a stable film on the working electrode. The structure and morphology of the PPyPIL films were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy and solid-state NMR (ssNMR) spectroscopy. The spectroscopy results confirmed the successful polymerization of Py to PPy and PIL monomer to PIL. The presence of (TFSI–) anions that balance the charge in PPyPIL was confirmed by EDX analysis. The electrical properties of PPyPIL in lithium bis(trifluoromethanesulfonyl)-imide (LiTFSI) aqueous and propylene carbonate solutions were examined with cyclic voltammetry (CV), chronoamperometry, and chronopotentiometry. The blend of PPyPIL had mixed electronic/ionic conductive properties that were strongly influenced by the solvent. In aqueous electrolyte, the electrical conductivity was 30 times lower and the diffusion coefficient 1.5 times higher than in the organic electrolyte. Importantly, the capacity, current density, and charge density were found to stay consistent, independent of the choice of solvent.

Cryogenic auxiliary drilling of printed circuit boards

Purpose Large capacity current carrier printed circuit board (PCB) imposes strict control requirements on the hole wall roughness. The key factors are chip removal, drilling temperature and tool wear. This paper aims to find out a cryogenic drilling process to control the chip removal, chip morphology, tool wear and finally reduce the hole wall roughness. Design/methodology/approach The chip removal process, chip morphology, tool wear and hole wall roughness of glass fiber epoxy resin copper clad laminate (FR-4) drilling were observed and analyzed. The influence of cold air on the chip removal process, chip morphology, tool wear and hole wall roughness was also investigated. An optimization process of cold air auxiliary drilling was proposed to control the hole wall roughness of FR-4. Findings The results showed that the discharge time of copper foil chips with obvious characteristics can be used as the evaluation criterion for the smoothness of chip removal. The cold air can promote chip removal and reduce tool wear. In addition, the chip removal and cooling performance will be the best when using −4.7 °C cold air with the injection angle consisted with the angle of helical flute of the drill. The hole wall roughness of FR-4 could be controlled by drilling with −4.7°C cold air. Originality/value This paper was the first study of the effect of three kinds of cold air on PCB drilling. This provided a reference for the possibility that the cryogenic drilling methods apply to PCB drilling. A new cold air auxiliary drilling process was developed for large capacity current carrier FR-4 manufacturing.

Electrical features of the engine starting system

The article describes the electrical properties of the engine starting system, that is the acid battery and the electric starter. The dependencies of battery voltage on independent variables affecting them, i.e. capacity, current, temperature or charge status, are discussed. The principles of operation of the battery and electric starter were described and its characteristics were presented, taking into account the properties of the load in the form of a resisting torque and being a source of battery energy. The possibilities of describing the characteristics of the starting system and determining the electrical parameters of the battery and the starter as components of the circuit, i.e. the electromotive force of the battery, resistance, inductance and capacity, are indicated.

The road less taken: Modularization and waterways as a domestic disaster response mechanism

Preparedness scenarios project the need for significant healthcare surge capacity. Current planning draws heavily from the military model, leveraging deployable infrastructure to augment or replace extant capabilities. This approach would likely prove inadequate in a catastrophic disaster, as the military model relies on forewarning and an extended deployment cycle. Local equipping for surge capacity is prohibitively costly while movement of equipment can be subject to a single point of failure. Translational application of maritime logistical techniques and an ancient mode of transportation can provide a robust and customizable approach to disaster relief for greater than 90 percent of the American population.

Study on a Permanent Magnet Bias Axial Magnetic Bearing

A permanent magnet bias axial magnetic bearing (PAMB) is introduced, the configuration and operation principle are analyzed; The equivalent magnetic circuit is established, the math expression of axial suspension force and some equations for carrying capacity, current stiffness and displacement stiffness are deduced; The parameters of the proposed prototype are also given. The magnetic field simulation is performed by using the Finite Element software. The theory analysis and the simulation results show that the presented PAMB has smaller volume, the control is easier; the parameters design is feasible and exact.