19,300 research outputs found
Great SCO2T! Rapid tool for carbon sequestration science, engineering, and economics
CO2 capture and storage (CCS) technology is likely to be widely deployed in
coming decades in response to major climate and economics drivers: CCS is part
of every clean energy pathway that limits global warming to 2C or less and
receives significant CO2 tax credits in the United States. These drivers are
likely to stimulate capture, transport, and storage of hundreds of millions or
billions of tonnes of CO2 annually. A key part of the CCS puzzle will be
identifying and characterizing suitable storage sites for vast amounts of CO2.
We introduce a new software tool called SCO2T (Sequestration of CO2 Tool,
pronounced "Scott") to rapidly characterizing saline storage reservoirs. The
tool is designed to rapidly screen hundreds of thousands of reservoirs, perform
sensitivity and uncertainty analyses, and link sequestration engineering
(injection rates, reservoir capacities, plume dimensions) to sequestration
economics (costs constructed from around 70 separate economic inputs). We
describe the novel science developments supporting SCO2T including a new
approach to estimating CO2 injection rates and CO2 plume dimensions as well as
key advances linking sequestration engineering with economics. Next, we perform
a sensitivity and uncertainty analysis of geology combinations (including
formation depth, thickness, permeability, porosity, and temperature) to
understand the impact on carbon sequestration. Through the sensitivity analysis
we show that increasing depth and permeability both can lead to increased CO2
injection rates, increased storage potential, and reduced costs, while
increasing porosity reduces costs without impacting the injection rate (CO2 is
injected at a constant pressure in all cases) by increasing the reservoir
capacity.Comment: CO2 capture and storage; carbon sequestration; reduced-order
modeling; climate change; economic
MULTIPLE-OBJECTIVE DECISION MAKING FOR AGROECOSYSTEM MANAGEMENT
Multiple-objective decision making (MODEM) provides an effective framework for integrated resource assessment of agroecosystems. Two elements of integrated assessment are discussed and illustrated: (1) adding noneconomic objectives as constraints in an optimization problem; and (2) evaluating tradeoffs among competing objectives using the efficiency frontier for objectives. These elements are illustrated for a crop farm and watershed in northern Missouri. An interactive, spatial decision support system (ISDSS) makes the MODEM framework accessible to unsophisticated users. A conceptual ISDSS is presented that assesses the socioeconomic, environmental, and ecological consequences of alternative management plans for reducing soil erosion and nonpoint source pollution in agroecosystems. A watershed decision support system based on the ISDSS is discussed.Agribusiness,
Modeling and Simulation of Solar Photovoltaic Cell for the Generation of Electricity in UAE
This paper proposes the implementation of a circuit based simulation for a
Solar Photovoltaic (PV) cell in order to get the maximum power output. The
model is established based on the mathematical model of the PV module. As the
PV cell is used to determine the physical and electrical behavior of the cell
corresponding to environmental factors such as temperature and solar
irradiance, this paper evaluates thirty years solar irradiation data in United
Arab Emirates (UAE), also analyzes the performance parameters of PV cell for
several locations. Based on the Shockley diode equation, a solar PV module is
presented. However, to analyze the performance parameters, Solarex MSX 120, a
typical 120W module is selected. The mathematical model for the chosen module
is executed in Matlab. The consequence of this paper reflects the effects of
variation of solar irradiation on PV cell within UAE. Conclusively, this paper
determines the convenient places for implementing the large scale solar PV
modules within UAE.Comment: To be published in 5th International Conference on Advances in
Electrical Engineering (ICAEE-2019
The LBFGS Quasi-Newtonian Method for Molecular Modeling Prion AGAAAAGA Amyloid Fibrils
Experimental X-ray crystallography, NMR (Nuclear Magnetic Resonance)
spectroscopy, dual polarization interferometry, etc are indeed very powerful
tools to determine the 3-Dimensional structure of a protein (including the
membrane protein); theoretical mathematical and physical computational
approaches can also allow us to obtain a description of the protein 3D
structure at a submicroscopic level for some unstable, noncrystalline and
insoluble proteins. X-ray crystallography finds the X-ray final structure of a
protein, which usually need refinements using theoretical protocols in order to
produce a better structure. This means theoretical methods are also important
in determinations of protein structures. Optimization is always needed in the
computer-aided drug design, structure-based drug design, molecular dynamics,
and quantum and molecular mechanics. This paper introduces some optimization
algorithms used in these research fields and presents a new theoretical
computational method - an improved LBFGS Quasi-Newtonian mathematical
optimization method - to produce 3D structures of Prion AGAAAAGA amyloid
fibrils (which are unstable, noncrystalline and insoluble), from the potential
energy minimization point of view. Because the NMR or X-ray structure of the
hydrophobic region AGAAAAGA of prion proteins has not yet been determined, the
model constructed by this paper can be used as a reference for experimental
studies on this region, and may be useful in furthering the goals of medicinal
chemistry in this field
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A review of microgrid development in the United States – A decade of progress on policies, demonstrations, controls, and software tools
Microgrids have become increasingly popular in the United States. Supported by favorable federal and local policies, microgrid projects can provide greater energy stability and resilience within a project site or community. This paper reviews major federal, state, and utility-level policies driving microgrid development in the United States. Representative U.S. demonstration projects are selected and their technical characteristics and non-technical features are introduced. The paper discusses trends in the technology development of microgrid systems as well as microgrid control methods and interactions within the electricity market. Software tools for microgrid design, planning, and performance analysis are illustrated with each tool's core capability. Finally, the paper summarizes the successes and lessons learned during the recent expansion of the U.S. microgrid industry that may serve as a reference for other countries developing their own microgrid industries
Learned Cardinalities: Estimating Correlated Joins with Deep Learning
We describe a new deep learning approach to cardinality estimation. MSCN is a
multi-set convolutional network, tailored to representing relational query
plans, that employs set semantics to capture query features and true
cardinalities. MSCN builds on sampling-based estimation, addressing its
weaknesses when no sampled tuples qualify a predicate, and in capturing
join-crossing correlations. Our evaluation of MSCN using a real-world dataset
shows that deep learning significantly enhances the quality of cardinality
estimation, which is the core problem in query optimization.Comment: CIDR 2019. https://github.com/andreaskipf/learnedcardinalitie
Structural Estimation and Solution of International Trade Models with Heterogeneous Firms
We present an empirical implementation of a general-equilibrium model of international trade with heterogeneous manufacturing firms. The theory underlying our model is consistent with Melitz (2003). A nonlinear structural estimation procedure identifies a set of core parameters and unobserved firm-level trade frictions that best fit the geographic pattern of trade. Once the parameters are identified, we utilize a decomposition technique for computing general-equilibrium counterfactuals. We first assess the economic effects of reductions in measured tariffs. Taking the simple-average welfare change across regions the Melitz structure indicates welfare gains from liberalization that are nearly four times larger than in a standard trade policy simulation. Furthermore, when we compare the economic impact of tariff reductions with reductions in estimated fixed trade costs we find that policy measures affecting the fixed costs are of greater importance than tariff barriers
An approach for real world data modelling with the 3D terrestrial laser scanner for built environment
Capturing and modelling 3D information of the built environment is a big challenge. A number of techniques and technologies are now in use. These include EDM, GPS, and photogrammetric application, remote sensing and traditional building surveying applications. However, use of these technologies cannot be practical and efficient in regard to time, cost and accuracy. Furthermore, a multi disciplinary knowledge base, created from the studies and research about the regeneration aspects is fundamental: historical, architectural, archeologically, environmental, social, economic, etc. In order to have an adequate diagnosis of regeneration, it is necessary to describe buildings and surroundings by means of documentation and plans. However, at this point in time the foregoing is considerably far removed from the real situation, since more often than not it is extremely difficult to obtain full documentation and cartography, of an acceptable quality, since the material, constructive pathologies and systems are often insufficient or deficient (flat that simply reflects levels, isolated photographs,..). Sometimes the information in reality exists, but this fact is not known, or it is not easily accessible, leading to the unnecessary duplication of efforts and resources.
In this paper, we discussed 3D laser scanning technology, which can acquire high density point data in an accurate, fast way. Besides, the scanner can digitize all the 3D information concerned with a real world object such as buildings, trees and terrain down to millimetre detail Therefore, it can provide benefits for refurbishment process in regeneration in the Built Environment and it can be the potential solution to overcome the challenges above. The paper introduce an approach for scanning buildings, processing the point cloud raw data, and a modelling approach for CAD extraction and building objects classification by a pattern matching approach in IFC (Industry Foundation Classes) format. The approach presented in this paper from an undertaken research can lead to parametric design and Building Information Modelling (BIM) for existing structures. Two case studies are introduced to demonstrate the use of laser scanner technology in the Built Environment. These case studies are the Jactin House Building in East Manchester and the Peel building in the campus of University Salford. Through these case studies, while use of laser scanners are explained, the integration of it with various technologies and systems are also explored for professionals in Built Environmen
REMIND-D: A Hybrid Energy-Economy Model of Germany
This paper presents a detailed documentation of the hybrid energy-economy model REMIND-D. REMIND-D is a Ramsey-type growth model for Germany that integrates a detailed bottom-up energy system module, coupled by a hard link. The model provides a quantitative framework for analyzing long-term domestic CO2 emission reduction scenarios. Due to its hybrid nature, REMIND-D facilitates an integrated analysis of the interplay between technological mitigation options in the different sectors of the energy system as well as overall macroeconomic dynamics. REMIND-D is an intertemporal optimization model, featuring optimal annual mitigation effort and technology deployment as a model output. In order to provide transparency on model assumptions, this paper gives an overview of the model structure, the input data used to calibrate REMIND-D to the Federal Republic of Germany, as well as the techno-economic parameters of the technologies considered in the energy system module.Hybrid Model, Germany, Energy System, Domestic Mitigation
Optimization of Renewable Energy-Based Smart Micro-Grid System
Optimization of renewable energy-based micro-grids is presently attracting significant consideration. Hence the main objective of this chapter is to evaluate the technical and economic performance of a micro-grid (MG) comparing between two operation modes; stand-alone (off-grid), and grid connected (on-grid). The micro-grid system (MGS) suggested components are; PV panels, wind turbine(s) inverter, and control unit in case of grid connected. In the stand alone mode diesel generator and short term storage are added to the renewable generators. To investigate the performance of the MGS; technically, detailed models for each component will be presented then the complete MGS model is developed. Another objective of this study is the economical evaluation of MGS by comparing the system net present cost (NPC) and cost of generated electricity for the two modes of operation; off-grid and on-grid
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