by Nicholas J Cook

Received: 14 April 2021;  Published: 25 June 2021;  doi: 10.21926/jept.2102027

A refined and extended version of the Offset Elliptical Normal mixture model has been developed to parameterise the seasonal diurnal wind vector automatically. Automated using R scripts, the method eliminates any potential risk of confirmation bias posed by the manual supervision in the original method. Refinements to the method include the latest algorithms for clustering of Gaussian mixtures, with Bayesian regularisation to set the number of components and to limit the predisposition to overfit. A new extension u [...]

by Peng Li  , Chi-Yao Chang  and Amsini Sadiki

Received: 02 April 2021;  Published: 28 June 2021;  doi: 10.21926/jept.2102026

A numerical model describing the ballistic behavior of a commercially used initiator is presented in this article. This model was built on the principle of conservation of mass and energy in the multi-phase framework incorporated with multi-loaded conditions. After obtaining the information about the grain size distribution in each composite, a fixing factor was proposed based on the surface area ratio of the composites. Thus, the solid propellant burning process based on distributed grain size was described, and t [...]

by Shih-Ang Hsu

Received: 16 April 2021;  Published: 16 June 2021;  doi: 10.21926/jept.2102025

During a tropical cyclone (TC) worldwide, the Regional and Mesoscale Meteorological Branch (RAMMB) of NOAA/NESDIS (http://rammb.cira.colostate.edu/) issues real-time TC surface wind analyses. The purpose of this article is to provide value-added estimations of several meteorological and oceanographic (met-ocean) parameters including overwater friction velocity and turbulence intensity, variation of the wind speed with height, significant wave height, peak or dominant wave period, wind-driven currents and wind-stres [...]

by Andrew C. Chien  , Eric Y. Lin  and Nicole J. Ye

Received: 26 April 2021;  Published: 11 June 2021;  doi: 10.21926/jept.2102024

The metallic copper, alkaline earth metal oxide, boron, and perovskite were incorporated on the surface of a Ni-cermet anode, and the performance of the modified Solid Oxide Fuel Cell (SOFC) anode was evaluated. The cell performance was analyzed by voltage-current characteristics (V-I curve) and H2-CH4 step reactions (P-t curve) in a potentiostatic mode. Besides, we also determined if a metallic phase or high electronic conductivity of the anode is important for a cell to perform well when H2 is used as a fuel, whe [...]

by Ganisetti Vijay Kumar  , Min-Ze Lu  and Chang-Ming Liaw

Received: 19 December 2020;  Published: 31 May 2021;  doi: 10.21926/jept.2102023

This paper presents the development of a high-performance electric vehicle (EV) synchronous reluctance motor (SynRM) drive and its vehicle-to-grid (V2G) and vehicle-to-microgrid (V2M) bidirectional operations. The EV motor drive boostable DC-link voltage is established by a battery through a bilateral interface boost-buck DC-DC converter for good driving performance over a wide speed range. The motor efficiency is 92.3% near the rated load. In idle conditions, the embedded interface converter and inverter of the mo [...]

by Arianna Massaro  , Ana B. Muñoz-García  , Mariarosaria Tuccillo  , Michele Pavone  and Pier Paolo Prosini

Received: 02 November 2020;  Published: 10 June 2021;  doi: 10.21926/jept.2102022

The current state-of-the-art quantum mechanics methodologies were applied to derive information on the bulk and surface properties of the P2-type layered oxide Na0.85Li0.17Ni0.21Mn0.64O2 (NLNMO), a cathode material. The special quasi-random structure (SQS) approach was employed to identify the arrangement of Li, Ni, and Mn ions in a supercell containing 115 atoms. Both the cell parameters and atomic positions were determined from DFT-PBE+U calculations to highlight specific distortions induced by the dopants (Ni an [...]

by George Z. Voyiadjis  and Peter I. Kattan

Received: 27 October 2020;  Published: 10 May 2021;  doi: 10.21926/jept.2102021

A robust mathematical method for the characterization of damage in carbon nanotubes is presented the presentation here is limited to elasticity. In this regard, the second and third order elastic stiffnesses are employed. All this is based on damage mechanics. The hypotheses of elastic strain equivalence and elastic energy equivalence are utilized. A new damage variable is proposed that is defined in terms of the surface area. This is in contrast to the classical damage variable which is defined in terms of the cro [...]

by Antonio Vázquez-López  , Marina García-Carrión  , Erlend Hall  , Anisa Yaseen  , Ilknur Kalafat  , María Taeño  , Junjie Zhu  , Xinyu Zhang  , Elif Arici  , Omer Suat Taskin  , David Maestre  , Emilio Nogales  , Pedro Hidalgo  , Julio Ramírez-Castellanos  , Bianchi Méndez  , Neslihan Yuca  , Smagul Karazhanov  , Erik S. Marstein  and Ana Cremades

Received: 09 November 2020;  Published: 08 May 2021;  doi: 10.21926/jept.2102020

Hybrid composites based on inorganic nanomaterials embedded into a polymer matrix have were synthesized and characterized. Oxide semiconductor nanoparticles (SnO, SnO2, TiO2, Ga2O3, and NiO) and Si nanoparticles were employed as inorganic counterparts in the hybrid composite, while a conductive polymer (PEDOT:PSS) with diverse additives was used as the organic matrix. The composites were spin-coated on Si or glass substrates. The potential use of these materials in photovoltaic devices to improve Si surface passiva [...]

by Nobuyuki Imanishi  , Tao Zhang  , Daishuke Mori  , Sou Taminato  , Yashuo Takeda  and osamu yamamoto

Received: 21 February 2021;  Published: 08 May 2021;  doi: 10.21926/jept.2102019

Because lithium metal exhibits high specific capacity and low potential, it is the best candidate for fabricating anodes for batteries. Rechargeable batteries fabricated using lithium anode exhibit high capacity and high potential cathode; these can be potentially used to fabricate high energy density batteries (>500 Wh kg-1) that can be used for the development of next-generation electric vehicles. However, the formation and growth of lithium dendrites and the low coulombic efficiency recorded during lithiu [...]

by Yi-Chun Hsu  , Min-Ze Lu  and Chang-Ming Liaw

Received: 18 December 2020;  Published: 28 April 2021;  doi: 10.21926/jept.2102018

This paper proposes a Wind Turbine Emulator (WTE) using an Indirect Field Oriented (IFO) Induction Motor (IM). The IM drive can be controlled as a conventional prime mover in speed mode, or a wind turbine in torque-speed mode via robust observed torque control. This paper presents key issues for establishing a high-performance IFO IM drive. Further, this study develops a wind turbine load Interior Permanent-Magnet Synchronous Generator (IPMSG) followed by a three-phase Vienna Switch-Mode Rectifier (SMR). It receive [...]