Development of a novel method to characterize shock waves interaction with solid objects
Not Available
Rahman, Mohammad Sazedur↗
Engineering topics
Mohamed, Ahmed
Publications and source records attributed to Mohamed, Ahmed.
EMOS (Energy Management Optimization System) [SWR-21-46]
EMOS software performs a real-time hierarchal optimal control for energy systems like multi-port electric vehicles charging site with distributed energy resources (DERs) and energy storage systems (ESSs). It gathers information in real-time from electric vehicles, power grid, and DERs, solves a multi-objective energy management optimization problem, and output setpoint for chargers, ESS converters, DERs converters, and grid converters. The software incorporates a novel integration of two control tasks: a) An Energy Management Optimization (EMO), which is the brain of EMOS controller that gathers information in real-time from EVs [e.g., battery size, state-of-charge (SOC), desired SOC, and charge acceptance curve], grid (e.g., electricity price, allowed feeder capacity, ramp rate limit, and reactive power), and DERs (e.g., prediction for solar generation for PV systems). It solves a control optimization problem in real-time to find optimal setpoint for ESSs power dispatch, EVs charging rate, and grid inverters. The objectives are to (1) minimize the charging cost considering grid energy, demand charges, and battery energy, (2) minimize charging time to meet fast charging criterion, (3) keep high energy level on ESSs at the end of an operating period, while satisfying constraints related to grid, EVs, and power converters. b) Real-Time Energy Management System (RT-EMS) is a rule-based algorithm that has faster response than EMO. It receives optimal setpoint from EMO and actual measurements from the system and modify the setpoint to compensate for any fast disturbance in the system, until a new optimum solution is received. Fast disturbances may include vehicle connect/disconnect, unpredicted variation in DERs profiles, variation in grid voltage, errors in PV generation prediction, and others. In addition, RT-EMS regulates voltage at point of common coupling (PCC) by managing reactive power of grid converters.
Mohamed, Ahmed↗
An empirical study of amide-heteroarene [pi]-stacking interactions using reversible inhibitors of a bacterial serine hydrolase
Abstract not provided
DeFrees, Kyle↗
SMART Mobility. Advanced Fueling Infrastructure Capstone Report
The U.S. Department of Energy’s Systems and Modeling for Accelerated Research in Transportation (SMART) Mobility Consortium is a multiyear, multi-laboratory collaborative, managed by the Energy Efficient Mobility Systems Program of the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, dedicated to further understanding the energy implications and opportunities of advanced mobility technologies and services. The first three-year research phase of SMART Mobility occurred from 2017 through 2019 and included five research pillars: Connected and Automated Vehicles, Mobility Decision Science, Multi-Modal Freight, Urban Science, and Advanced Fueling Infrastructure. A sixth research thrust integrated aspects of all five pillars to develop a SMART Mobility Modeling Workflow to evaluate new transportation technologies and services at scale. This report summarizes the work of the Advanced Fueling Infrastructure Pillar. This Pillar investigated the charging infrastructure needs of electric ride-hailing and car-sharing vehicles, automated shuttle buses, and freight-delivery truck fleets. For information about the other Pillars and about the SMART Mobility Modeling Workflow, please refer to the relevant Pillar’s Capstone Report.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
A molecular dynamics investigation of hydrostatic compression characteristics of mineral Jennite
This paper focuses on the study of mechanical behavior and deformation of mineral Jennite, under isothermal hydrostatic compression using Molecular Dynamics (MD) modeling. Atomistic structure of mineral Jennite is considered as a choice for representing calcium silicate hydrate (C-S-H), a key constituent in hydrated cement paste. The present work focuses and presents a molecular dynamics simulation approach to ascertain hydrostatic compression characteristics of mineral Jennite. The pressure–specific volume, and specific internal energy–specific volume relationships under isothermal hydrostatic compression conditions were determined. For the pressures ranging from 0.0001 GPa to 5 GPa, computational modeling results indicated that a linear relationship may be sufficient when describing the pressure–specific volume relationship. The results obtained in this study compared well with experimental and theoretical results recently published by other researchers. Additionally, a quadratic function was found to be appropriate to describe the specific energy–specific volume relationship, for the same pressure range used for studying the pressure–specific volume relationship. The pressure–specific volume, and specific internal energy-specific volume relationships reported in this paper are useful for further estimation of pressure–specific volume constitutive Hugoniot of the nanoscale mineral Jennite. Additionally, MD approach discussed and presented in this paper can be applied to understand hydrostatic compression behavior and deformation characteristics of other atomistic structures representing C-S-H. Further, the computational material modeling approach discussed in this paper provides an alternative methodology that can aid in the understanding of the deformation mechanisms and developing constitutive relationships from atomistic structures of materials.
36 MATERIALS SCIENCE↗
Aquifer recharge, depletion, and connectivity: Inferences from GRACE, land surface models, and geochemical and geophysical data
We used data from the Gravity Recovery and Climate Experiment (GRACE) and outputs of the CLM4.5 model to estimate recharge and depletion rates for large aquifers, investigate the connectivity of an aquifer's subbasins, and identify barriers and preferred pathways for groundwater flow within an aquifer system. The Nubian Sandstone Aquifer System and its subbasins (Dakhla, Northern Sudan Platform, and Kufra) in northeast Africa were used for demonstration purposes, and findings were tested and verified against geological, geophysical, remote sensing, geochronologic, and geochemical data. There are four major findings. (1) The average annual precipitation data over recharge areas in the southern Kufra section and the Northern Sudan Platform subbasin were estimated at 54.8 km 3 , and 32.8 km 3 , respectively, and knowing the annual extraction rates over these two areas (similar to 0.40 ± 0.20 km 3 ), recharge rates were estimated at 0.78 ± 0.49 km 3 /yr and 1.44 ± 0.42 km 3 /yr, respectively. (2) GRACEderived groundwater depletion rates over the Dakhla subbasin and the Northern Kufra section were estimated at 4.44 ± 0.42 km 3 /yr and 0.48 ± 0.32 km 3 /yr, respectively. (3) The observed depletion in the southern parts of the Dakhla subbasin is apparently caused by the presence of the east- west- trending Uweinat-Aswan basement uplift, which impedes the south-to-north groundwater flow and hence reduces replenishment from recharge areas in the south. (4) A major northeast- southwest- trending shear zone (Pelusium shear system) is apparently providing a preferred groundwater flow pathway from the Kufra to the Dakhla subbasin. Thus, inte-grated approach provides a replicable and cost-effective model for better understanding of the hydrogeologic setting of large aquifers worldwide and for optimum management of these groundwater resources.
58 GEOSCIENCES↗