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Topic Review
Sustainable Assessment of Concrete Repairs
In order to improve the sustainability of concrete structures and repairs over their life cycle, life cycle assessment (LCA) and life cycle cost analysis (LCCA) should be applied. Life cycle assessment (LCA) is a holistic method to determine the environmental impact of a product or process with a systematic set of procedures for compiling and examining the inputs and outputs of materials and energy during the entire life cycle. A life cycle is the interlinked stages of a product or service system, from the extraction of natural resources to final disposal (cradle-to-grave). LCCA is a systematic or analytical method to determine the economic performance of a product or process during the entire life cycle, when the initial cost is taken into account, along with future cash flows incurred throughout the lifespan over a predefined period of analysis. The future cash flows are often taken into account by discounting, which compares costs and revenues at different stages in time and emphasizes the importance of present cash flows rather than future ones due to inflation and the earning power of money.
  • 884
  • 21 Oct 2022
Topic Review
Ionic Liquids and Lignin
This entry gives overview of the lignin separation methods from lignocellulosic biomass using various methods but the main attention has been paid on lignin separation using ionic liquids. Lignin is a natural polymer, one that has an abundant and renewable resource in biomass. Due to a tendency towards the use of biochemicals, the efficient utilization of lignin has gained wide attention. The delignification of lignocellulosic biomass makes its fractions (cellulose, hemicellulose, and lignin) susceptible to easier transformation to many different commodities like energy, chemicals, and materials that could be produced using the biorefinery concept. 
  • 884
  • 10 Oct 2020
Topic Review
Substrate Materials of Microfluidic-Microwave Devices
The area of microfluidic devices with microwave components is constantly increasing. There are four main types of materials, that can act as a substrate for the microwave-microfluidic systems—epoxy-glass laminates, polymer materials, glass/silicon substrates, and Low-Temperature Cofired Ceramics (LTCCs). The entry describes and compares briefly all selected materials.
  • 883
  • 22 Apr 2021
Topic Review
The Lean Blowout Prediction Techniques
The lean blowout is the most critical issue in lean premixed gas turbine combustion. Decades of research into LBO prediction methods have yielded promising results. Predictions can be classified into five categories based on methodology: semi-empirical model, numerical simulation, hybrid, experimental, and data-driven model.
  • 883
  • 30 Nov 2022
Topic Review
Sequrity aspects in Smart Meters
Smart meters are of the basic elements in the so-called Smart Grid. These devices, connected to the Internet, keep bidirectional communication with other devices in the Smart Grid structure to allow remote readings and maintenance. As any other device connected to a network, smart meters become vulnerable to attacks with different purposes, like stealing data or altering readings. Nowadays, it is becoming more and more popular to buy and plug-and-play smart meters, additionally to those installed by the energy providers, to directly monitor the energy consumption at home. This option inherently entails security risks that are under the responsibility of householders. In this paper, we focus on an open solution based on Smartpi 2.0 devices with two purposes. On the one hand, we propose a network configuration and different data flows to exchange data (energy readings) in the home. These flows are designed to support collaborative among the devices in order to prevent external attacks and attempts of corrupting the data. On the other hand, we check the vulnerability by performing two kind of attacks (denial of service and stealing and changing data by using a malware).
  • 883
  • 27 Oct 2020
Topic Review
Biofuels for Spark Ignition Engines
Biofuels are receiving increased scientific attention, and recently different biofuels have been proposed for spark ignition engines. Different biofuels, mainly ethanol, methanol, i-butanol-n-butanol, and acetone, are blended together in single dual issues and evaluated as renewables for SIE. Each blend showed some advantaged and drawbacks in terms of emissions and performance. 
  • 883
  • 17 Mar 2021
Topic Review
Categories of Step-Up DC-DC Converters
MICs can have either single-stage or two-stages conversion systems: single-stage MICs perform voltage boosting, MPPT and grid current control in a single DC-AC power conversion; two-stages MICs have a DC-DC stage to boost the PV module DC voltage (between 20 V–45 V) to a higher value (above 380 V, for instance) while tracking the PV module maximum power point, followed by a DC-AC stage, responsible to DC-link voltage regulation and the grid-tied functions.
  • 883
  • 05 Jan 2022
Topic Review
Class E Power Amplifier
This entry aims to solve a problem that exists with impedance matching networks in terms of extra cost and power loss of electronic components in a four-coil wireless power transfer (WPT) system using class E power amplifier as power supply, which is not conducive to the improvement of system efficiency and output power. A design method of sharing the resonant inductor in class E power amplifier and the excitation coil in the four-coil WPT system is proposed. This method comprehensively considers the output power and transfer efficiency of the system, the number of coil turns, coil size and many other factors. Compared with the traditional four-coil system using a class E power amplifier as a power supply, the proposed method simplified the system structure by leaving out a resonant inductor and load matching circuit, which can reduce the power loss of system and improve efficiency. Moreover, the precisely tuning of resonant inductor was not necessary, which improved the stability of the system. The correctness and feasibility of the parameter design method were verified by experiments. The experimental results showed that the output power of the system was increased by 18.7%, the efficiency was increased by 11%, and the transmission distance was up to 0.7 m, which is suitable for wireless power supply of electronics and sensors.
  • 882
  • 29 Oct 2020
Topic Review
EOR's Significance in Emission Reduction
Limiting the increase in CO2 concentrations in the atmosphere, and at the same time, meeting the increased energy demand can be achieved by applying carbon capture, utilization and storage (CCUS) technologies, which hold potential as the bridge for energy and emission-intensive industries to decarbonization goals. At the moment, the only profitable industrial large-scale carbon sequestration projects are large-scale carbon dioxide enhanced oil recovery (CO2-EOR) projects. This paper gives a general overview of the indirect and direct use of captured CO2 in CCUS with a special focus on worldwide large-scale CO2-EOR projects. On the basis of scientific papers and technical reports, data from 23 contemporary large-scale CO2-EOR projects in different project stages were aggregated, pointing out all the specificities of the projects. The specificities of individual projects, along with the lack of standardized methodologies specific for estimating the full lifecycle emissions resulting from CO2-EOR projects, pose a challenge and contribute to uncertainties and wide flexibilities when estimating emissions from CO2-EOR projects, making the cross-referencing of CO2-EOR projects and its comparison to other climate-mitigation strategies rather difficult. Pointing out the mentioned project’s differentiations and aggregating data on the basis of an overview of large-scale CO2-EOR projects gives useful information for future work on the topic of a CO2-EOR project’s lifecycle emissions.
  • 882
  • 17 Jun 2021
Biography
Percy Spencer
Percy Lebaron Spencer (July 19, 1894 – September 8, 1970) was an United States physicist and inventor. He became known as the inventor of the microwave oven.[1] Spencer was born in Howland, Maine. Eighteen months later, Spencer's father died, and his mother soon left him in the care of his aunt and uncle. His uncle then died when Spencer was just seven years old. Spencer subsequently left g
  • 882
  • 27 Dec 2022
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