13 research outputs found
DFTB+, a software package for efficient approximate density functional theory based atomistic simulations
DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green's functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives
The species-area relationship: new challenges for an old pattern
The species-area relationship (i.e., the relationship between area and the number of species found in that area) is one of longest and most frequently studied patterns in nature. Yet there remain some important and interesting questions on the nature of this relationship, its causality, quantification and application for both ecologists and conservation biologists.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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Washington State Biomass Data Book
This is the first edition of the Washington State Biomass Databook. It assess sources and approximate costs of biomass fuels, presents a view of current users, identifies potential users in the public and private sectors, and lists prices of competing energy resources. The summary describes key from data from the categories listed above. Part 1, Biomass Supply, presents data increasing levels of detail on agricultural residues, biogas, municipal solid waste, and wood waste. Part 2, Current Industrial and Commercial Use, demonstrates how biomass is successfully being used in existing facilities as an alternative fuel source. Part 3, Potential Demand, describes potential energy-intensive public and private sector facilities. Part 4, Prices of Competing Energy Resources, shows current suppliers of electricity and natural gas and compares utility company rates. 49 refs., 43 figs., 72 tabs
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1994 Washington State directory of Biomass Energy Facilities
This is the fourth edition of the Washington Directory of Biomass Energy Facilities, the first edition was published in 1987. The purpose of this directory is to provide a listing of and basic information about known biomass producers and users within the state to help demonstrate the importance of biomass energy in fueling our state`s energy needs. In 1992 (latest statistical year), estimates show that the industrial sector in Washington consumed nearly 128 trillion Btu of electricity, nearly 49.5 trillion Btu of petroleum, over 82.2 trillion Btu of natural gas, and over 4.2 trillion Btu of coal. Facilities listed in this directory generated approximately 114 trillion Btu of biomass energy - 93 trillion were consumed from waste wood and spent chemicals. In the total industrial energy picture, wood residues and chemical cooking liquors placed second only to electricity. This directory is divided into four main sections biogas production, biomass combustion, ethanol production, and solid fuel processing facilities. Each section contains maps and tables summarizing the information for each type of biomass. Provided in the back of the directory for reference are a conversion table, a table of abbreviations, a glossary, and an index. Chapter 1 deals with biogas production from both landfills and sewage treatment plants in the state. Biogas produced from garbage and sewage can be scrubbed and used to generate electricity. At the present time, biogas collected at landfills is being flared on-site, however four landfills are investigating the feasibility of gas recovery for energy. Landfill biogas accounted for approximately 6 percent of the total biomass reported. Sewage treatment biogas accounted for 0.6 percent. Biogas generated from sewage treatment plants is primarily used for space and process heat, only one facility presently scrubs and sells methane. Together, landfill and sewage treatment plant biogas represented over 6.6 percent of the total biomass reported
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1990 Washington State Directory of Biomass Energy Facilities
This second edition is an update of biomass energy production and use in Washington State for 1989. The purpose of this directory is to provide a listing of known biomass users within the state and some basic information about their facilities. The data can be helpful to persons or organizations considering the use of biomass fuels. The directory is divided into three sections of biomass facilities with each section containing a map of locations and a data summary table. In addition, a conversion table, a glossary and an index are provided in the back of the directory. The first section deals with biogas production from wastewater treatment plants. The second section provides information on the wood combustion facilities in the state. This section is subdivided into two categories. The first is for facilities connected with the forest products industries. The second category include other facilities using wood for energy. The third section is composed of three different types of biomass facilities -- ethanol, municipal solid waste, and solid fuel processing. Biomass facilities included in this directory produce over 64 trillion Btu (British thermal units) per year. Wood combustion facilities account for 91 percent of the total. Biogas and ethanol facilities each produce close to 800 billion Btu per year, MSW facilities produce 1845 billion BTU, and solid fuel processing facilities produce 2321 billion Btu per year. To put these numbers in perspective, Washington's industrial section uses 200 trillion Btu of fuels per year. Therefore, biomass fuels used and/or produced by facilities listed in this directory account for nearly 32 percent of the state's total industrial fuel demand. This is a sizable contribution to the state's energy needs