by Gerald Jandl  , Rainer Horn  , Richard Schroeder  , Kai-Uwe Eckhardt  and Peter Leinweber

Received: 23 November 2022;  Published: 22 March 2023;  doi: 10.21926/jept.2301012

The increasing number of biogas plants with various digested organic materials and output of digestates calls for more detailed investigations of their suitability as soil amendments. In a trial in Northern Germany two replicate plots each were treated with fresh or prolonged fermented digestate to investigate the influence of digestates on the composition of soil organic matter (SOM). The relative proportions of relevant SOM compound classes were determined by pyrolysis-field ionization mass spectrometry (Py-FIMS) [...]

by Silvio Simani  , Saverio Farsoni  and Paolo Castaldi

Received: 02 February 2023;  Published: 21 March 2023;  doi: 10.21926/jept.2301011

In agreement with the Editor-in-Chief, the editorial office, and the authors, this article has been removed and marked as retracted because its content and data contained plagiarism from an unpublished study. Please refer to the Removal Statement.

by Junmo Moon  , Satita Thiangtham  , Ruijie Zheng  , Sicheng Liu  , Chayanaphat Chokradjaroen  , Yasuyuki Sawada  and Nagahiro Saito

Received: 04 December 2022;  Published: 20 February 2023;  doi: 10.21926/jept.2301010

Crystalline lithium fluoride (LiF) has been intensively pursued as potential alternative solid electrolytes (SEs) owing to its excellent chemical and electrochemical oxidation stability, and good deformability. However, due to its low ion conductivity, LiF is still challenging for practical SE applications. Herein, Li-Zr-F composite-based SE by liquid-mediated synthesis is proposed to be studied. methanol (CH3OH) was mainly evaluated as a liquid-mediated precursor for synthesizing Li-Zr-F composites under the stoic [...]

by Daming Zhang

Received: 06 December 2022;  Published: 17 February 2023;  doi: 10.21926/jept.2301009

To increase power level in an autonomous microgrid, higher voltage is necessary. In this paper, detailed Matlab/Simulink modeling of a microgrid operated at medium-voltage level and at constant frequency has been conducted. Modified boost converter and medium-frequency transformer isolated DC/DC converter are adopted for both solar energy and wind energy harnessing in order for them to be connected with the microgrid. This paper further adopted a differential evolution (DE)-based method to carry out load flow analy [...]

by Minghan Bao  , Nagi Abdussamie  and Faisal AlThobiani

Received: 03 December 2022;  Published: 09 February 2023;  doi: 10.21926/jept.2301008

Analysing the structural response of offshore wind turbines (OWTs) requires a robust method to estimate environmental loadings associated with extreme weather conditions. This study aimed to accurately predict wind loadings on a non-rotating OWT using a Computational Fluid Dynamics (CFD) code, Ansys Fluent package. The inlet velocity boundary condition was defined as a uniform inlet wind speed and then as a Normal Wind Profile (NWP). Three large wind speeds of 25 m/s, 40 m/s and 50 m/s were tested with the aid of t [...]

by Naireeta Deb  and Rajendra Singh

Received: 15 November 2022;  Published: 08 February 2023;  doi: 10.21926/jept.2301007

Widespread adoption of electric vehicles has presented the challenges of short range and prolonged charging time. Going forward, extremely fast charging is the only solution to these problems. However, the typical Silicon power electronics supported 400 V electric vehicle powertrain cannot live up to this challenge. Limitations include the huge cable size, heating of equipment due to high current and user safety, to name a few. In this paper, we have analyzed an 800 V EV powertrain using power electronics based on [...]

by Koorosh Goudarzi  and AliReza R. Taghizadeh

Received: 31 December 2022;  Published: 06 February 2023;  doi: 10.21926/jept.2301006

In this paper, due to the importance of energy recovery from internal combustion engines and the increasing human growing need for power and refrigeration, a two-cycle power and refrigeration system consisting of an organic Rankine cycle and an ejector refrigeration cycle is investigated analytically. The proposed system with the ability to use the ejector as an effective and economical system, can produce simultaneous power and refrigeration by drawing thermal energy from the exhaust gas and engine coolant in the [...]

by Kenji Amagai  , Hiroto Kotake  , Masahiro Munemura  , Sawako Shigeto  and Masayuki Horio

Received: 10 October 2022;  Published: 02 February 2023;  doi: 10.21926/jept.2301005

This paper describes the development of low-speed electric community buses (LSECBs) designed by the author's group and their spread situation in Japan. LSECBs are electric vehicles that can travel on public roads at speeds of less than 5.56 m/s (20 km/h). The university, local government, local businesses, and residents with a co-design approach developed the LSECBs. They have various advantages such as safety due to low speed and low energy consumption. In particular, the LSECBs have features not found in ordinary [...]

by Cenk Temizel  , Hakki Aydin  , F. Bahar Hosgor  , Cengiz Yegin  and C. Shah Kabir

Received: 25 September 2022;  Published: 28 January 2023;  doi: 10.21926/jept.2301004

In recent years, the oil and gas sector has been moving towards green production methods to achieve net-zero emission goals. Governments and corporations have started large-scale initiatives to deploy advanced technologies to reduce carbon footprints and prevent global warming. Herein, we have explored the emerging techniques and methods used in reducing the effects of gas emissions in the oil and gas industry. The transition process from hydrocarbons to renewable energy resources, including solar thermal applicati [...]

by Andrew Williams  and Murray Thomson

Received: 09 November 2022;  Published: 09 January 2023;  doi: 10.21926/jept.2301003

This paper examines the economic case for the UK to proceed urgently with the installation of thermal insulation and heat pumps in most UK buildings, in the context of the legal requirement to achieve net-zero carbon emissions by 2050. A recent study by the same authors assumed that such insulation and heat pumps would be in place, and showed how the whole of the UK’s energy demand could be met by low carbon electricity generation and appropriate storage. This paper extends the modelling to consider the risk that i [...]