Table of Content

Open Access Original Research

Study of Hydrogen Embrittlement in Pipelines and Nuclear Power Plants: Estimates for Durability

Received: 18 April 2022;  Published: 30 August 2022;  doi: 10.21926/jept.2203028

Abstract

Due to the increasing need to further develop the world gas and oil industry and the increased public attention to clean energy sources, studying and preventing Hydrogen Induced Cracking is one of the main safety concerns in nuclear power plants, oil pipelines and platforms. In this article, the growth and incubation times for internal Hydrogen Induced Cracks (HIC) are examined. Specifically, these times are modeled in two separate phases - the first phase (I) is a long time approximation, when the crack growth is [...]

584 5642

Open Access Review

Artificial Neural Networks and Gradient Boosted Machines Used for Regression to Evaluate Gasification Processes: A Review

Received: 18 February 2022;  Published: 18 August 2022;  doi: 10.21926/jept.2203027

Abstract

Waste-to-Energy technologies have the potential to dramatically improve both the natural and human environment. One type of waste-to-energy technology that has been successful is gasification. There are numerous types of gasification processes and in order to drive understanding and the optimization of these systems, traditional approaches like computational fluid dynamics software have been utilized to model these systems. The modern advent of machine learning models has allowed for accurate and computationally ef [...]

704 5273

Open Access Original Research

Incentivizing Alternative Fuel Vehicle Transactions: Analysis of Cash-for-Clunkers Transactions for New Alternative Fuel Vehicles

Received: 14 January 2022;  Published: 02 August 2022;  doi: 10.21926/jept.2203026

Abstract

Monetary incentives to accelerate the transition of private vehicle fleets to zero emissions promote sustainability in the transportation sector. Clean Cars for America to incentivize transactions for new battery power vehicles is a program in furtherance of sustainable transportation goals in the United States. Unfortunately, data on transactions for new alternative fuel vehicles (AFVs) are scarce so empirical research to explore the costs and/or the benefits of such programs is also scarce. Analysis of transactio [...]

499 4041

Open Access Technical Note

From Food to Foot: The Energy and Carbon Flows of the Human Body at Walking and Cycling

Received: 10 March 2022;  Published: 18 July 2022;  doi: 10.21926/jept.2203025

Abstract

The carbon footprint of motorized transport modes per unit length traveled encompasses the unit share of the vehicle lifetime emissions, that of the transport infrastructure, and those of the motor energy, considered both from “well to tank” and from “tank to wheel”. In the active modes of transport, i.e., walking and cycling, the counterpart of motor energy is human energy, which is associated with two kinds of carbon flows: the carbon footprint of food intake, – which we call the Food to Body component – and the [...]

756 6006

Open Access Original Research

Numerical Study to Understand the Conservation of Hydrogen Through a Dynamic Fuel Supply System in Proton Exchange Membrane Fuel Cells (PEMFCs)

Received: 26 March 2022;  Published: 13 July 2022;  doi: 10.21926/jept.2203024

Abstract

Reducing and conserving fuel usage is pivotal for any engineering system for the development of a sustainable energy solution. Proton exchange membrane fuel cells (PEMFCs) are one of the promising renewable energy systems that consume hydrogen as their source of fuel to generate electricity. This paper investigate the necessity of the constant supply of fuel (hydrogen) in the PEMFC system to ensure stable operation. We propose that a dynamic supply of fuel could help achieve similar performance and reduce the amoun [...]

644 5414

Open Access Original Research

Surface Treatment of Flexible Barrier Film for Improved Stability of Organic Photovoltaic Mini Modules

Received: 07 March 2022;  Published: 04 July 2022;  doi: 10.21926/jept.2203023

Abstract

The lifetime and stability of organic photovoltaics (OPVs) are the key factors that influence the technology used to scale up and commercialize OPVs. High-performing and reliable devices are used to fabricate the devices of choice. Materials and methods that can be used to prevent the degradation of organic materials, enabling better OPV applications, are being increasingly researched in recent years. Herein, we present the surface modification process of a commercial, flexible barrier film based on polyethylene te [...]

914 6371

Open Access Original Research

Analysis of LoRa Transmission Delay on Dynamic Performance of Standalone DC Microgrids

Received: 18 April 2022;  Published: 26 June 2022;  doi: 10.21926/jept.2202022

Abstract

One important aspect toward proper and stable functioning of a communication-based controlled microgrid is data transmission. Consequently, an analysis of the effect of data transmission delay is of significance for any chosen communication protocol. This paper focuses on the effect of employing LoRa for data transfer at the secondary control level of a standalone DC microgrid. It analyses the effect of LoRa transmission delay on the dynamic performance of DC microgrids. This paper simulates a community DC microgri [...]

728 6340

Open Access Research Article

Controller Evaluation for Solar-Latent Thermal Energy Applications

Received: 17 April 2022;  Published: 09 June 2022;  doi: 10.21926/jept.2202021

Abstract

In this study, the performance of a self-sufficient controller used for a solar-latent heat domestic hot water (DHW) production unit under real-world operating conditions was analyzed. The unit consists of a flat-plate solar collector and a latent heat storage tank. The controller is powered by a small solar panel and governs the charging and discharging of the system, ensuring maximum solar energy absorption, desired hot water temperature, and constant monitoring of the heat-storage tank’s capacity. The system is [...]

553 4822

Open Access Original Research

Improving the Engine Efficiency Using a New Combined Refrigeration Cycle for Low-Temperature Heat Source (Waste Heat Recovery)

Received: 19 April 2022;  Published: 08 June 2022;  doi: 10.21926/jept.2202020

Abstract

Passenger and commercial internal combustion engines have relatively large dissipated thermal energy sources that can be used for initiating thermodynamic refrigeration cycles at low temperatures while improving engine efficiency. Researchers have focused on combined power-refrigeration cycles in past studies. This paper presents the operation and performance of a new combined refrigeration system driven by waste heat recovery within the internal combustion engines. For this purpose, the effects of several paramete [...]

629 4772

Open Access Research Article

Analysis of Correlations for the Prediction of the Entrainment Fraction of Droplets in Gas-liquid Annular Flows

Received: 14 February 2022;  Published: 24 May 2022;  doi: 10.21926/jept.2202019

Abstract

In gas-liquid flows, droplets that detach from the liquid film lining the internal walls of a pipe and merge with the gas flowing through the pipe follow an annular flow pattern. This work analyzes correlations for estimating the entrainment fraction of such droplets contained in the literature by comparing their predictions with experimental data also from the literature. The results of this comparative study demonstrate that the analyzed correlations do not accurately reproduce experimental conditions. This is du [...]

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