WorldWideScience

Sample records for af compressed air

  1. Air Facility System (AFS) Widget

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Air Facility System (AFS) widget allows users to enter a specific location and retrieve facilities in the area of interest for stationary sources of air...

  2. EPA Facility Registry Service (FRS): AIRS_AFS Sub Facilities

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Air Facility System (AFS) contains compliance and permit data for stationary sources regulated by EPA, state and local air pollution agencies. The sub facility...

  3. 29 CFR 1926.803 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Compressed air. 1926.803 Section 1926.803 Labor Regulations... Compressed Air § 1926.803 Compressed air. (a) General provisions. (1) There shall be present, at all times... medical aspects of compressed air work and the treatment of decompression illness. He shall be...

  4. 29 CFR 1917.154 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  5. Aerometric Information Retrieval System/AIRS Facility Subsystem (AIRS/AFS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aerometric Information Retrieval System/AIRS Facility Subsystem (AIRS/AFS) is a database that provides information on air releases from various stationary...

  6. Chapter 22: Compressed Air Evaluation Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Benton, N.

    2014-11-01

    Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: high-efficiency/variable speed drive (VSD) compressor replacing modulating compressor; compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.

  7. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Society of Mechanical Engineers, 22 Law Drive, P.O. Box 2900, Fairfield, New Jersey 07007, Phone:...

  8. Industrial Compressed Air System Energy Efficiency Guidebook.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1993-12-01

    Energy efficient design, operation and maintenance of compressed air systems in industrial plants can provide substantial reductions in electric power and other operational costs. This guidebook will help identify cost effective, energy efficiency opportunities in compressed air system design, re-design, operation and maintenance. The guidebook provides: (1) a broad overview of industrial compressed air systems, (2) methods for estimating compressed air consumption and projected air savings, (3) a description of applicable, generic energy conservation measures, and, (4) a review of some compressed air system demonstration projects that have taken place over the last two years. The primary audience for this guidebook includes plant maintenance supervisors, plant engineers, plant managers and others interested in energy management of industrial compressed air systems.

  9. Efficiency of Compressed Air Energy Storage

    OpenAIRE

    Elmegaard, Brian; Brix, Wiebke

    2011-01-01

    The simplest type of a Compressed Air Energy Storage (CAES) facility would be an adiabatic process consisting only of a compressor, a storage and a turbine, compressing air into a container when storing and expanding when producing. This type of CAES would be adiabatic and would if the machines were reversible have a storage efficiency of 100%. However, due to the specific capacity of the storage and the construction materials the air is cooled during and after compression in practice, making...

  10. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-11-30

    This document provides specifications for the process air compressor for a compressed air storage project, requests a budgetary quote, and provides supporting information, including compressor data, site specific data, water analysis, and Seneca CAES value drivers.

  11. Adiabatic Liquid Piston Compressed Air Energy Storage

    OpenAIRE

    Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

    2013-01-01

    This project investigates the potential of a Compressed Air Energy Storage system (CAES system). CAES systems are used to store mechanical energy in the form of compressed air. The systems use electricity to drive the compressor at times of low electricity demand with the purpose of converting the mechanical energy into electricity at times of high electricity demand. Two such systems are currently in operation; one in Germany (Huntorf) and one in the USA (Macintosh, Alabama). In both cases, ...

  12. Compressed Air/Vacuum Transportation Techniques

    Science.gov (United States)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  13. Adiabatic Liquid Piston Compressed Air Energy Storage

    DEFF Research Database (Denmark)

    Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

    This project investigates the potential of a Compressed Air Energy Storage system (CAES system). CAES systems are used to store mechanical energy in the form of compressed air. The systems use electricity to drive the compressor at times of low electricity demand with the purpose of converting the...... compensates the added investment. •When comparing ALP-CAES to an adiabatic CAES system, where compression heat is stored in thermal oil, the ALP-CAES system is found only to be competitive under a very specific set of operating/design conditions, including very high operation pressure and the use of very...... primarily due to the investment in turbine/generator, heat exchangers, and a large quantity of thermal oil. To improve the economy, it would be relevant to investigate the possibility of replacing the thermal oil by water, for example by injecting the water directly into the air flow between the different...

  14. AIRMaster: Compressed air system audit software

    International Nuclear Information System (INIS)

    The project goal was to develop a software tool, AIRMaster, and a methodology for performing compressed air system audits. AIRMaster and supporting manuals are designed for general auditors or plant personnel to evaluate compressed air system operation with simple instrumentation during a short-term audit. AIRMaster provides a systematic approach to compressed air system audits, analyzing collected data, and reporting results. AIRMaster focuses on inexpensive Operation and Maintenance (O and M) measures, such as fixing air leaks and improving controls that can significantly improve performance and reliability of the compressed air system, without significant risk to production. An experienced auditor can perform an audit, analyze collected data, and produce results in 2--3 days. AIRMaster reduces the cost of an audit, thus freeing funds to implement recommendations. The AIRMaster package includes an Audit Manual, Software and User's manual, Analysis Methodology Manual, and a Case Studies summary report. It also includes a Self-Guided Tour booklet to help users quickly screen a plant for efficiency improvement potentials, and an Industrial Compressed Air Systems Energy Efficiency Guidebook. AIRMaster proved to be a fast and effective audit tool. In sever audits AIRMaster identified energy savings of 4,056,000 kWh, or 49.2% of annual compressor energy use, for a cost savings of $152,000. Total implementation costs were $94,700 for a project payback period of 0.6 years. Available airflow increased between 11% and 51% of plant compressor capacity, leading to potential capital benefits from 40% to 230% of first year energy savings

  15. Compressibility of air in fibrous materials

    DEFF Research Database (Denmark)

    Tarnow, Viggo

    1996-01-01

    over thermal waves from all fibers, and by a self-consistent procedure. Figuren of the compressibility in the frequency range 10-100 000 Hz, are given for diameter of the cylinders of 6.8 µm, and mean distances between them from 50 to 110 µm, which corresponds to glass wool with a density of 40 to 16...... compressibility is computed approximately from the diameter and mean distances between cylinders. This requires calculation of the air temperature, which is calculated for cylinders in a regular lattive by the Wigner-Seitz cell approximation. In the case of random placement, the calculation is done by a summation...

  16. Economic Modeling of Compressed Air Energy Storage

    OpenAIRE

    Rui Bo; Ming Ni; Yang Gu; James McCalley

    2013-01-01

    Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES) in systems with large-scale wind power generation. The co-optimizatio...

  17. 41 CFR 50-204.8 - Use of compressed air.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Use of compressed air. 50-204.8 Section 50-204.8 Public Contracts and Property Management Other Provisions Relating to Public... General Safety and Health Standards § 50-204.8 Use of compressed air. Compressed air shall not be used...

  18. Efficiency of Compressed Air Energy Storage

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Brix, Wiebke

    2011-01-01

    were reversible have a storage efficiency of 100%. However, due to the specific capacity of the storage and the construction materials the air is cooled during and after compression in practice, making the CAES process diabatic. The cooling involves exergy losses and thus lowers the efficiency of the...... storage significantly. The efficiency of CAES as an electricity storage may be defined in several ways, we discuss these and find that the exergetic efficiency of compression, storage and production together determine the efficiency of CAES. In the paper we find that the efficiency of the practical CAES...... electricity storage is 25-45% and thus has a quite low efficiency, which is close to the efficiency of the simple diabatic CAES-process. Adiabatic CAES would reach significantly higher storage efficiency about 70-80%....

  19. Compressed Air Energy Storage in Denmark

    DEFF Research Database (Denmark)

    Salgi, Georges Garabeth; Lund, Henrik

    2006-01-01

    Compressed air energy storage system (CAES) is a technology which can be used for integrating more fluctuating renewable energy sources into the electricity supply system. On a utility scale, CAES has a high feasibility potential compared to other storage technologies. Here, the technology is...... analysed with regard to the Danish energy system. In Denmark, wind power supplies 20% of the electricity demand and 50% is produced by combined heat and power (CHP). The operation of CAES requires high electricity price volatility. However, in the Nordic region, large hydro capacities have so far kept the...

  20. Working Characteristics of Variable Intake Valve in Compressed Air Engine

    OpenAIRE

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design c...

  1. Operational experience of compressed air system for large accelerator complex

    International Nuclear Information System (INIS)

    Operation of various devices in Indus-1 and Indus-2 synchrotron radiation sources requires uninterrupted supply of instrument quality compressed air. For this purpose, a centralised compressed air system was commissioned in May 2005 and is operational on round the clock basis. Instrumentation was done for air quality monitoring at various stages of distribution. Availability and reliability of the system was analysed based on the failure data. In year 2008, compressed air system was upgraded to improve the reliability. In this paper, we present design philosophy, fabrication, installation, instrumentation, testing and availability of the compressed air system in Indus complex. (author)

  2. University of Arizona Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Joseph; Muralidharan, Krishna

    2012-12-31

    Boiled down to its essentials, the grant’s purpose was to develop and demonstrate the viability of compressed air energy storage (CAES) for use in renewable energy development. While everyone agrees that energy storage is the key component to enable widespread adoption of renewable energy sources, the development of a viable scalable technology has been missing. The Department of Energy has focused on expanded battery research and improved forecasting, and the utilities have deployed renewable energy resources only to the extent of satisfying Renewable Portfolio Standards. The lack of dispatchability of solar and wind-based electricity generation has drastically increased the cost of operation with these components. It is now clear that energy storage coupled with accurate solar and wind forecasting make up the only combination that can succeed in dispatchable renewable energy resources. Conventional batteries scale linearly in size, so the price becomes a barrier for large systems. Flow batteries scale sub-linearly and promise to be useful if their performance can be shown to provide sufficient support for solar and wind-base electricity generation resources. Compressed air energy storage provides the most desirable answer in terms of scalability and performance in all areas except efficiency. With the support of the DOE, Tucson Electric Power and Science Foundation Arizona, the Arizona Research Institute for Solar Energy (AzRISE) at the University of Arizona has had the opportunity to investigate CAES as a potential energy storage resource.

  3. Assessment of the market for compressed air services

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2001-01-01

    The objective of this report is to provide a comprehensive and balanced view of the market for engineering and consulting services to improve the energy efficiency of plant compressed air systems. The report is intended for use by Compressed Air Challenge and other industrial energy efficiency program operators in developing strategies to encourage the growth of the compressed air system efficiency and enhance the quality of the services it offers.

  4. Development of air fuel ratio sensor; A/F sensor no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sakawa, T.; Hori, M. [Denso Corp., Aichi (Japan); Nakamura, Y. [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    The Air Fuel Ratio Sensor (A/F sensor), which is applied to a 1997 model year Low Emission Vehicle (LEV) was developed. This sensor enables the detection of the exhaust gas air fuel ratio, both lean and rich of stoichiometric. It has an effective air fuel ratio range from 12 to 18 as required for LEV regulation. It has the fast light off, - within 20 seconds - to minimize exhaust hydrocarbon content. Further, it has fast response time, less than 200 msec, to improve the air fuel ratio controllability. 3 refs., 7 figs.

  5. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-11-30

    This report provides a review and an analysis of potential environmental justice areas that could be affected by the New York State Electric & Gas (NYSEG) compress air energy storage (CAES) project and identifies existing environmental burden conditions on the area and evaluates additional burden of any significant adverse environmental impact. The review assesses the socioeconomic and demographic conditions of the area surrounding the proposed CAES facility in Schuyler County, New York. Schuyler County is one of 62 counties in New York. Schuyler County’s 2010 population of 18,343 makes it one of the least populated counties in the State (U.S. Census Bureau, 2010). This report was prepared for WorleyParsons by ERM and describes the study area investigated, methods and criteria used to evaluate this area, and the findings and conclusions from the evaluation.

  6. Energy storage by compressed air. [using windpowered pumps

    Science.gov (United States)

    Szego, G. C.

    1973-01-01

    The feasibility of windpower energy storage by compressed air is considered. The system is comprised of a compressor, a motor, and a pump turbine to store air in caverns or aquifiers. It is proposed that storage of several days worth of compressed air up to 650 pounds per square inch can be used to push the aquifier up closer to the container dome and thus initiate piston action by simply compressing air more and more. More energy can be put into it by pressure increase or pushing back the water in the aquifier. This storage system concept has reheat flexibility and lowest cost effectiveness.

  7. Economic Modeling of Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Rui Bo

    2013-04-01

    Full Text Available Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES in systems with large-scale wind power generation. The co-optimization of energy and ancillary services markets is implemented in order to analyze the impacts of CAES, not only on energy supply, but also on system operating reserves. Both hourly and 5-minute simulations are considered to capture the economic performance of CAES in the day-ahead (DA and real-time (RT markets. The generalized network flow formulation is used to model the characteristics of CAES in detail. The proposed model is applied on a modified IEEE 24-bus reliability test system. The numerical example shows that besides the economic benefits gained through energy arbitrage in the DA market, CAES can also generate significant profits by providing reserves, compensating for wind forecast errors and intra-hour fluctuation, and participating in the RT market.

  8. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-11-30

    Compressed Air Energy Storage (CAES) is a hybrid energy storage and generation concept that has many potential benefits especially in a location with increasing percentages of intermittent wind energy generation. The objectives of the NYSEG Seneca CAES Project included: for Phase 1, development of a Front End Engineering Design for a 130MW to 210 MW utility-owned facility including capital costs; project financials based on the engineering design and forecasts of energy market revenues; design of the salt cavern to be used for air storage; draft environmental permit filings; and draft NYISO interconnection filing; for Phase 2, objectives included plant construction with a target in-service date of mid-2016; and for Phase 3, objectives included commercial demonstration, testing, and two-years of performance reporting. This Final Report is presented now at the end of Phase 1 because NYSEG has concluded that the economics of the project are not favorable for development in the current economic environment in New York State. The proposed site is located in NYSEG’s service territory in the Town of Reading, New York, at the southern end of Seneca Lake, in New York State’s Finger Lakes region. The landowner of the proposed site is Inergy, a company that owns the salt solution mining facility at this property. Inergy would have developed a new air storage cavern facility to be designed for NYSEG specifically for the Seneca CAES project. A large volume, natural gas storage facility owned and operated by Inergy is also located near this site and would have provided a source of high pressure pipeline quality natural gas for use in the CAES plant. The site has an electrical take-away capability of 210 MW via two NYSEG 115 kV circuits located approximately one half mile from the plant site. Cooling tower make-up water would have been supplied from Seneca Lake. NYSEG’s engineering consultant WorleyParsons Group thoroughly evaluated three CAES designs and concluded that any

  9. Analytical and experimental study on complex compressed air pipe network

    Science.gov (United States)

    Gai, Yushou; Cai, Maolin; Shi, Yan

    2015-09-01

    To analyze the working characteristics of complex compressed air networks, numerical methods are widely used which are based on finite element technology or intelligent algorithms. However, the effectiveness of the numerical methods is limited. In this paper, to provide a new method to optimize the design and the air supply strategy of the complex compressed air pipe network, firstly, a novel method to analyze the topology structure of the compressed air flow in the pipe network is initially proposed. A matrix is used to describe the topology structure of the compressed air flow. Moreover, based on the analysis of the pressure loss of the pipe network, the relationship between the pressure and the flow of the compressed air is derived, and a prediction method of pressure fluctuation and air flow in a segment in a complex pipe network is proposed. Finally, to inspect the effectiveness of the method, an experiment with a complex network is designed. The pressure and the flow of airflow in the network are measured and studied. The results of the study show that, the predicted results with the proposed method have a good consistency with the experimental results, and that verifies the air flow prediction method of the complex pipe network. This research proposes a new method to analyze the compressed air network and a prediction method of pressure fluctuation and air flow in a segment, which can predicate the fluctuation of the pressure according to the flow of compressed air, and predicate the fluctuation of the flow according to the pressure in a segment of a complex pipe network.

  10. Training Studies with Compressed Air Breathing Apparatus – Methodology, Exercises

    Directory of Open Access Journals (Sweden)

    Buks Roberts

    2015-11-01

    Full Text Available The current article describes topics ranging from the respiratory physiology and the structure of compressed air breathing apparatus to the performance of practical training exercises in an unbreathable environment (hereinafter referred to as UE.

  11. Economic and environmental evaluation of compressed-air cars

    International Nuclear Information System (INIS)

    Climate change and energy security require a reduction in travel demand, a modal shift, and technological innovation in the transport sector. Through a series of press releases and demonstrations, a car using energy stored in compressed air produced by a compressor has been suggested as an environmentally friendly vehicle of the future. We analyze the thermodynamic efficiency of a compressed-air car powered by a pneumatic engine and consider the merits of compressed air versus chemical storage of potential energy. Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix. However, a pneumatic-combustion hybrid is technologically feasible, inexpensive and could eventually compete with hybrid electric vehicles.

  12. Economic and environmental evaluation of compressed-air cars

    Science.gov (United States)

    Creutzig, Felix; Papson, Andrew; Schipper, Lee; Kammen, Daniel M.

    2009-10-01

    Climate change and energy security require a reduction in travel demand, a modal shift, and technological innovation in the transport sector. Through a series of press releases and demonstrations, a car using energy stored in compressed air produced by a compressor has been suggested as an environmentally friendly vehicle of the future. We analyze the thermodynamic efficiency of a compressed-air car powered by a pneumatic engine and consider the merits of compressed air versus chemical storage of potential energy. Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix. However, a pneumatic-combustion hybrid is technologically feasible, inexpensive and could eventually compete with hybrid electric vehicles.

  13. Acceptance Test Report for 241-U compressed air system

    International Nuclear Information System (INIS)

    This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027

  14. Ultrasound attenuation dependence on air compression or expansion processes

    OpenAIRE

    Jakevicius, L.; Demcenko, A.; Mardosaite, R.

    2010-01-01

    In this work variation of ultrasonic attenuation coefficient is analyzed in terms of air compression or expansion processes. In closed spaces changing air volume, the ultrasound attenuation coefficient depends on thermodynamic processes which occur during the air volume change. Two limiting cases are possible: 1) if the change of air volume is very slow or intensive heat exchange occurs between the system and surrounding environments, so the system stays in a thermodynamic equilibrium; theref...

  15. 46 CFR 112.50-7 - Compressed air starting.

    Science.gov (United States)

    2010-10-01

    ... AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-7 Compressed..., and energy storing devices must be in the emergency generator room, except for the main or auxiliary... emergency generator room and a handcranked, diesel-powered air compressor for recharging the air...

  16. Compressed air of water-injected screw compressors is clean; Druckluft von wassereingespritzten Schraubenkompressoren ist sauber

    Energy Technology Data Exchange (ETDEWEB)

    Thomassen, Volker

    2010-08-09

    The oil content of compressed air has become an issue in industrial compressed air supply, especially from the view of environmental protection and waste management. The article specifies requirements on compressed air systems that are to ensure clean compressed air supply. (orig.)

  17. Use of compressed-air storage systems; Einsatz von Druckluftspeichersystemen

    Energy Technology Data Exchange (ETDEWEB)

    Cyphely, I.; Rufer, A.; Brueckmann, Ph.; Menhardt, W.; Reller, A.

    2004-07-01

    This final report issued by the Swiss Federal Office of Energy (SFOE) looks at the use of compressed air as a means of storing energy. Historical aspects are listed and compressed-air storage as an alternative to current ideas that use electrolysis and hydrogen storage is discussed. The storage efficiency advantages of compressed-air storage is stressed and the possibilities it offers for compensating the stochastic nature of electricity production from renewable energy sources are discussed. The so-called BOP (Battery with Oil-hydraulics and Pneumatics) principle for the storage of electricity is discussed and its function is described. The advantages offered by such a system are listed and the development focus necessary is discussed.

  18. Geothermal well behaviour prediction after air compress stimulation using one-dimensional transient numerical modelling

    Science.gov (United States)

    Yusman, W.; Viridi, S.; Rachmat, S.

    2016-01-01

    The non-discharges geothermal wells have been a main problem in geothermal development stages and well discharge stimulation is required to initiate a flow. Air compress stimulation is one of the methods to trigger a fluid flow from the geothermal reservoir. The result of this process can be predicted by using by the Af / Ac method, but sometimes this method shows uncertainty result in several geothermal wells and also this prediction method does not take into account the flowing time of geothermal fluid to discharge after opening the well head. This paper presents a simulation of non-discharges well under air compress stimulation to predict well behavior and time process required. The component of this model consists of geothermal well data during heating-up process such as pressure, temperature and mass flow in the water column and main feed zone level. The one-dimensional transient numerical model is run based on the Single Fluid Volume Element (SFVE) method. According to the simulation result, the geothermal well behavior prediction after air compress stimulation will be valid under two specific circumstances, such as single phase fluid density between 1 - 28 kg/m3 and above 28.5 kg/m3. The first condition shows that successful well discharge and the last condition represent failed well discharge after air compress stimulation (only for two wells data). The comparison of pf values between simulation and field observation shows the different result according to the success discharge well. Time required for flow to occur as observed in well head by using the SFVE method is different with the actual field condition. This model needs to improve by updating more geothermal well data and modified fluid phase condition inside the wellbore.

  19. Compressed Air System Optimization: Case Study Food Industry in Indonesia

    Science.gov (United States)

    Widayati, Endang; Nuzahar, Hasril

    2016-01-01

    Compressors and compressed air systems was one of the most important utilities in industries or factories. Approximately 10% of the cost of electricity in the industry was used to produce compressed air. Therefore the potential for energy savings in the compressors and compressed air systems had a big challenge. This field was conducted especially in Indonesia food industry or factory. Compressed air system optimization was a technique approach to determine the optimal conditions for the operation of compressors and compressed air systems that included evaluation of the energy needs, supply adjustment, eliminating or reconfiguring the use and operation of inefficient, changing and complementing some equipment and improving operating efficiencies. This technique gave the significant impact for energy saving and costs. The potential savings based on this study through measurement and optimization e.g. system that lowers the pressure of 7.5 barg to 6.8 barg would reduce energy consumption and running costs approximately 4.2%, switch off the compressor GA110 and GA75 was obtained annual savings of USD 52,947 ≈ 455 714 kWh, running GA75 light load or unloaded then obtained annual savings of USD 31,841≈ 270,685 kWh, install new compressor 2x132 kW and 1x 132 kW VSD obtained annual savings of USD 108,325≈ 928,500 kWh. Furthermore it was needed to conduct study of technical aspect of energy saving potential (Investment Grade Audit) and performed Cost Benefit Analysis. This study was one of best practice solutions how to save energy and improve energy performance in compressors and compressed air system.

  20. Economic and technical feasibility study of compressed air storage

    Energy Technology Data Exchange (ETDEWEB)

    1976-03-01

    The results of a study of the economic and technical feasibility of compressed air energy storage (CAES) are presented. The study, which concentrated primarily on the application of underground air storage with combustion turbines, consisted of two phases. In the first phase a general assessment of the technical alternatives, economic characteristics and the institutional constraints associated with underground storage of compressed air for utility peaking application was carried out. The goal of this assessment was to identify potential barrier problems and to define the incentive for the implementation of compressed air storage. In the second phase, the general conclusions of the assessment were tested by carrying out the conceptual design of a CAES plant at two specific sites, and a program of further work indicated by the assessment study was formulated. The conceptual design of a CAES plant employing storage in an aquifer and that of a plant employing storage in a conventionally excavated cavern employing a water leg to maintain constant pressure are shown. Recommendations for further work, as well as directions of future turbo-machinery development, are made. It is concluded that compressed air storage is technically feasible for off-peak energy storage, and, depending on site conditions, CAES plants may be favored over simple cycle turbine plants to meet peak demands. (LCL)

  1. EFFECTS OF COMPRESSED AIR FOAM APPLICATION ON HEAT

    Directory of Open Access Journals (Sweden)

    Adam THOMITZEK

    2015-12-01

    Full Text Available This article evaluates the knowledge obtained in firefighting tests using compressed air foam system (CAFS within a confined space. Six experiments were conducted for verification during the cooling of rooms and the self-extinguishing effect. The simulation was for a fully developed fire within a room. The fuel was chosen to simulate ordinary combustible materials utilized in residential areas. Mantel thermocouples were placed in the rooms to record the temperature changes. Compressed air foam was first applied with a standard fire hose nozzle to the ceiling and then to the epicenter of fire. Fire extinguishing was initiated after reaching the desired temperature in the room. The temperature for the start of fire extinguishing matched the third phase of development of a fire. Fire extinguishing was terminated after no obvious signs of fire were shown in epicenter of fire. The outputs of the experiments were evaluated on the basis of the amount of time passed for the temperature to drop below the suggested limit. Individual experiments were also conducted with various different admixing foaming agents over different locations. In the experiments, it has been verified that the application of compressed air foam has a positive effect on room cooling. Use of a compressed air foaming agent does not allow for the development of steam that can scald firefighters and reduce visibility. Furthermore, the extinguishing agent used is more efficient utilizing less water flow out of the fire area.

  2. Improving Compressed Air System Performance: A Sourcebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-11-01

    NREL will produce this sourcebook for DOE's Industrial Technologies Office as part of a series of documents on industrial energy equipment. The sourcebook is a reference for industrial compressed air system users, outlining opportunities to improve system efficiency.

  3. Legal and regulatory issues affecting compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.

    1981-07-01

    Several regulatory and legal issues that can potentially affect implementation of a compressed air energy storage (CAES) system are discussed. This technology involves the compression of air using base load electric power for storage in an underground storage medium. The air is subsequently released and allowed to pass through a turbine to generate electricity during periods of peak demand. The storage media considered most feasible are a mined hard rock cavern, a solution-mined cavern in a salt deposit, and a porous geologic formation (normally an aquifer) of suitable structure. The issues are discussed in four categories: regulatory issues common to most CAES facilities regardless of storage medium, regulatory issues applicable to particular CAES reservoir media, issues related to possible liability from CAES operations, and issues related to acquisition of appropriate property rights for CAES implementation. The focus is on selected federal regulation. Lesser attention is given to state and local regulation. (WHK)

  4. Rupture of sigmoid colon caused by compressed air.

    Science.gov (United States)

    Yin, Wan-Bin; Hu, Ji-Lin; Gao, Yuan; Zhang, Xian-Xiang; Zhang, Mao-Shen; Liu, Guang-Wei; Zheng, Xue-Feng; Lu, Yun

    2016-03-14

    Compressed air has been generally used since the beginning of the 20(th) century for various applications. However, rupture of the colon caused by compressed air is uncommon. We report a case of pneumatic rupture of the sigmoid colon. The patient was admitted to the emergency room complaining of abdominal pain and distention. His colleague triggered a compressed air nozzle against his anus as a practical joke 2 h previously. On arrival, his pulse rate was 126 beats/min, respiratory rate was 42 breaths/min and blood pressure was 86/54 mmHg. Physical examination revealed peritoneal irritation and the abdomen was markedly distended. Computed tomography of the abdomen showed a large volume of air in the abdominal cavity. Peritoneocentesis was performed to relieve the tension pneumoperitoneum. Emergency laparotomy was done after controlling shock. Laparotomy revealed a 2-cm perforation in the sigmoid colon. The perforation was sutured and temporary ileostomy was performed as well as thorough drainage and irrigation of the abdominopelvic cavity. Reversal of ileostomy was performed successfully after 3 mo. Follow-up was uneventful. We also present a brief literature review. PMID:26973403

  5. CLASSIFICATION OF THE MGR SUBSURFACE COMPRESSED AIR SYSTEM

    International Nuclear Information System (INIS)

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface compressed air system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  6. CLASSIFICATION OF THE MGR SITE COMPRESSED AIR SYSTEM

    International Nuclear Information System (INIS)

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) site compressed air system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  7. SEPARATION AND ANALYSIS OF OIL BASED AEROSOLS FROM COMPRESSED AIR

    Directory of Open Access Journals (Sweden)

    N.Azhaguvel,

    2011-04-01

    Full Text Available Air braking system is one of the critical component in ensuring the safety of the commercial vehicle. Quality of air supplied to the brake system should be dry and free form impurities. Some amountof lubrication oil of the compressor will get carried along with the compressed air. Oil which was carried away will be in the form of aerosols. These oil aerosols will reduce the absorptive capacity of the desiccant of air dryer, wear out of valves of brake chamber and also erode system components. This work focus on developing a concept to remove the oil aerosols. Multiphase CFD simulation has been carried out to find the efficiency of filter in removing the oil aerosols, and pressure drop across the filter. This work also includes developing a prototype of filter and performing experimental analysis. Both the results of CFD analysis as well as the experimental analysis are matching.

  8. Prefeasibility study on compressed air energy storage systems

    Science.gov (United States)

    Elmahgary, Y.; Peltola, E.; Sipilae, K.; Vaeaetaeinen, A.

    1991-08-01

    A prefeasibility study on compressed air energy storage (CALS) systems was launched in VTT in the course of the year 1990. The study was undertaken partly in the Laboratory of Electrical and Automation Engineering and partly in the Road, Traffic and Geotechnical Laboratory. Information on existing mines in Finland which could be used as storage caverns were collected (part 2). The costs of excavating rock caverns for compressed air storage and those for forming suitable storage caverns in existing mines were also estimated. This information was used in the first (and present) part of the report to calculate the economics of CAES. In the present part (part 1) of the study, an analysis of the different possible systems was given following a review of literature on CAES. This was followed by an economic analysis which comprised two separate systems. The first consisted of conventional oil fueled gas turbine plants provided with the CALS system. In the second system, wind turbines were used to run the compressors which are used in charging the compressed air storage cavern. The results of the current prefeasibility study confirmed the economic attractiveness of the CAES in the first system. Wind turbines still seem, however, to be too expensive to compete with coal power plants. More accurate and straight-forward results could be obtained only in a more comprehensive study.

  9. Evaluating Fault Detection and Diagnostics Protocols Applied to Air-Cooled Vapor Compression Air-Conditioners

    OpenAIRE

    Yuill, David P.; Braun, James E.

    2012-01-01

    Fault detection and diagnostics (FDD) tools are being increasingly applied in air-conditioning systems. There are many different protocols used in these FDD tools, so an important question to ask is: how well do the protocols work? This paper describes the ongoing development of the first standardized method of evaluation for FDD protocols applied to air-cooled vapor compression air-conditioning systems. The general approach is to feed a library of data – including temperatures, pressures, an...

  10. Dynamic compressibility of air in porous structures at audible frequencies

    DEFF Research Database (Denmark)

    Lafarge, Denis; Lemarinier, Pavel; Allard, Jean F.;

    1997-01-01

    Measurements of dynamic compressibility of air-filled porous sound-absorbing materials are compared with predictions involving two parametere, the static thermal permeability k'_0 and the thermal characteristic dimension GAMMA'. Emphasis on the notion of dynamic and static thermal permeability...... - the latter being a geometrical parameter equal to the inverse trapping constant ot the solid frame - in apparently new.The static thermal permeability plays, in the description of the thermal exchanges between frame and saturating fluid, a role similar to the viscous permeability in the desription...... of the viscous forces. Using both parameters, a simple model is constructed for the dynamic thermal permeability k', which is completely analogous to the Johnson et al. [J. Fluid Mech. vol. 176, 379 (1987)] model of dynamic viscous permeability k. The resultant modeling of dynamic compressibility provides...

  11. Compressive Earth Observatory: An Insight from AIRS/AMSU Retrievals

    CERN Document Server

    Ebtehaj, Ardeshir Mohammad; Lerman, Gilad; Bras, Rafael Luis

    2014-01-01

    We demonstrate that the global fields of temperature, humidity and geopotential heights admit a nearly sparse representation in the wavelet domain, offering a viable path forward to explore new paradigms of sparsity-promoting assimilation and compressive retrieval of spaceborne earth observations. We illustrate this idea using retrieval products of the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit (AMSU) on board the Aqua satellite. The results reveal that the sparsity of the fields of temperature and geopotential height is relatively pressure-independent while atmospheric humidity fields are typically less sparse at higher pressures. Using the sparsity prior, we provide evidence that the global variability of these land-atmospheric states can be accurately estimated from space in a compressed form, using a small set of randomly chosen measurements/retrievals.

  12. Exergy Analysis of the Revolving Vane Compressed Air Engine

    OpenAIRE

    Alison Subiantoro; Kin Keong Wong; Kim Tiow Ooi

    2016-01-01

    Exergy analysis was applied to a revolving vane compressed air engine. The engine had a swept volume of 30 cm3. At the benchmark conditions, the suction pressure was 8 bar, the discharge pressure was 1 bar, and the operating speed was 3,000 rev·min−1. It was found that the engine had a second-law efficiency of 29.6% at the benchmark conditions. The contributors of exergy loss were friction (49%), throttling (38%), heat transfer (12%), and fluid mixing (1%). A parametric study was also conduct...

  13. Geothermally Coupled Well-Based Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Casie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cabe, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-20

    Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

  14. Geothermally Coupled Well-Based Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, C L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-01

    Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

  15. Claw-pole Synchronous Generator for Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    PAVEL Valentina

    2013-05-01

    Full Text Available This paper presents a claw-poles generator for compressed air energy storage systems. It is presented the structure of such a system used for compensating of the intermittency of a small wind energy system. For equipping of this system it is chosen the permanent magnet claw pole synchronous generator obtained by using ring NdFeB permanentmagnets instead of excitation coil. In such a way the complexity of the scheme is reduced and the generator become maintenance free. The new magnetic flux density in the air-gap is calculated by magneticreluctance method and by FEM method and the results are compared with measured values in the old and new generator.

  16. Methods for Sampling and Measurement of Compressed Air Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L.

    1976-10-15

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  17. Methods for Sampling and Measurement of Compressed Air Contaminants

    International Nuclear Information System (INIS)

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  18. Carbon and energy saving markets in compressed air

    Science.gov (United States)

    Cipollone, R.

    2015-08-01

    CO2 reduction and fossil fuel saving represent two of the cornerstones of the environmental commitments of all the countries of the world. The first engagement is of a medium to long term type, and unequivocally calls for a new energetic era. The second delays in time the fossil fuel technologies to favour an energetic transition. In order to sustain the two efforts, new immaterial markets have been established in almost all the countries of the world, whose exchanges (purchases and sales) concern CO2 emissions and equivalent fossil fuels that have not been emitted or burned. This paper goes deep inside two aspects not yet exploited: specific CO2 emissions and equivalent fossil fuel burned, as a function of compressed air produced. Reference is made to the current compressor technology, carefully analysing CAGI's (Compressed Air Gas Institute) data and integrating it with the PNUEROP (European Association of manufacturers of compressors, vacuum pumps, pneumatic tools and allied equipment) contribution on the compressor European market. On the base of energy saving estimates that could be put in place, this article also estimates the financial value of the CO2 emissions and fossil fuels avoided.

  19. Analysis and Proof‐of‐Concept Experiment of Liquid‐Piston Compression for Ocean Compressed Air Energy Storage (OCAES) System

    OpenAIRE

    Park, Joong-kyoo; Ro, Paul I.; He, Xiao; Mazzoleni, Andre P.

    2014-01-01

    An analysis and a proof‐of‐concept experiment of liquid‐piston compression were conducted for a table‐top Ocean Compressed Air Energy Storage (OCAES) prototype. A singlecylinder‐ type piston surrounded by water was modeled and analyzed based on convection heat transfer with fully developed internal flow, the assumption adopted by earlier liquid piston study in literature. Transient numerical results of this model were calculated for a polytropic compression with different polytropic index val...

  20. Commercial concepts for adiabatic compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Sebastian [General Electric Global Research, Garching (Germany); Schainker, Robert [Electric Power Research Institute, Palo Alto, CA (United States); Moreau, Robert [General Electric Oil and Gas, Florence (Italy)

    2012-07-01

    Adiabatic compressed air energy storage (ACAES) systems offer the potential for efficient large-scale energy storage, almost approaching values typical for pumped hydro. In an ACAES plant, the heat of compression is stored and utilized during the expansion of the air instead of firing natural gas like in commercial CAES. However, no ACAES plants have been commercialized due to challenges with respect to the cost and the heat storage technology. In this study, conducted by EPRI, GE Global Research and GE Oil and Gas, several concepts for ACAES plants are analyzed and their efficiency, complexity and technical risk compared. The components selected for the plants are available either off-the-shelf or near-commercial within a short development time and without the high costs associated with developing a new generation of large custom-made compressors and turbines. The most promising concept for near-term commercialization and low costs turns out to be a two-stage, low-temperature ACAES system. A regenerative (solid) and a recuperative (liquid) thermal storage system have been designed and analyzed for this concept, with the result that the liquid-recuperative system offers a much lower cost and comparable performance. Performance and cost targets for the concepts are 100 MW output per plant for 6 h with a round-trip efficiency above 60% and a capital cost of about $1000/kW. Selections of the turbomachinery for the compression and expansion train from General Electric Oil and Gas are presented for several plant options along with their expansion power range (25..100 MW), round-trip efficiency (66%..70%) and preliminary capital cost estimates (1100..1200 $/kW).

  1. A proposed compressed air drying method using pressurized liquid desiccant and experimental verification

    International Nuclear Information System (INIS)

    Highlights: • A novel compressed air drying method using pressurized liquid desiccant was proposed. • Experiments verified the method and get compressed air with the humidity of 0.9 g/kg. • Energy efficiency was analyzed to show the energy saving potential of the new method. - Abstract: A novel compressed air drying method using pressurized liquid desiccant is proposed in this paper. The compressed air drying system is consisted of a compressed air module, a pressurized liquid desiccant dehumidifier, a liquid desiccant regenerator working in an atmospheric pressure, and other auxiliary components. An experimental apparatus of the pressurized liquid desiccant dehumidifier associated with a compressed air module is established to verify the proposed air drying method experimentally. The results show that, under the pressure of 0.5 MPa, the moisture content in the outlet air can reach 0.9 g/kg. The moisture content of the outlet air reaches 1.4 g/kg under the pressure of 0.3 MPa, and the power consumption of the drying system is 6.17 kJ/g, which is 0.69 kJ/g and 10.1% lower than the conventional compressed air cooling drying system. The dehumidification efficiency is around 0.90, indicating the sufficiently mass transfer between compressed air and solution in pressurized dehumidifier. Besides, the proposed compressed air drying system can use the low-grade heat from the air compressor to regenerate the diluted desiccant solution. The novel air drying method is verified to offer very dry air for industrial application, and shows significant energy saving potential compared with the conventional compressed air cooling drying system

  2. Environmental impact of an industrial compressed air system for solar power in South Africa

    OpenAIRE

    Gouws, Rupert

    2012-01-01

    Almost 14% of the electricity generated by the national energy supplier (Eskom) in South Africa is sold directly to the mining sector and almost 20% is utilized directly by the compressed air systems of the mining sector. The industrial compressed air systems in South Africa therefore have a substantial impact on the environment in terms of emissions output. In this paper a solar powered compressor is installed parallel to an existing industrial compressed air system. The environmental (emiss...

  3. Improving Compressed Air System Performance: A Sourcebook for Industry v3

    Energy Technology Data Exchange (ETDEWEB)

    Ron Marshall, William Scales, Gary Shafer, Paul Shaw, Paul Sheaffer, Rick Stasyshan, H.P.

    2016-03-01

    This sourcebook is designed to provide compressed air system users with a reference that outlines opportunities for system performance improvements. It is not intended to be a comprehensive technical text on improving compressed air systems, but rather a document that makes compressed air system users aware of the performance improvement potential, details some of the significant opportunities, and directs users to additional sources of assistance.

  4. Compressed-air: results of an analysis made for the Clariant company; Ergebnisse der Druckluftanalyse Clariant

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, R. [Fraunhofer-Institut fuer Systemund Innovationsforschung (ISI), Karlsruhe (Germany); Stadelmann, B. [Hochschule fuer Technik und Architektur Luzern (HTA), Horw (Switzerland)

    2005-05-15

    This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the compressed-air supply at the facilities of the Clariant company in Muttenz, Switzerland. The various compressors and compressed-air installations in the company's facilities are described and detailed technical data is presented. The control of these systems and the distribution of the compressed air is discussed. Needs, usage and consumption of compressed air is analysed at macro and detail levels. Leakage is looked at as is the dimensioning of the distribution systems. Finally, possibilities for making savings are presented.

  5. Atopy, airway reactivity and compressed air diving in males.

    Science.gov (United States)

    Tetzlaff, K; Neubauer, B; Reuter, M; Friege, L

    1998-01-01

    A decline in expiratory flow rates in divers has recently been attributed to chronic exposure to hyberbaric air. Airway hyperresponsiveness (AHR) to stimuli due to a hyperbaric environment may play a certain role in this context. The aim of this study was to determine the prevalence of AHR in compressed air divers and to assess the value of bronchial challenges for prediction of fitness to dive. A cross-sectional sample of 59 healthy male volunteers--28 divers and 31 diving candidates (controls)--who had been found fit to dive in a diving medical examination underwent additional allergy screening (skin prick and serum IgE) and a histamine bronchial challenge. Pre- and postchallenge body plethysmography was completed to assess AHR. AHR to histamine was significantly increased among divers and positively related to diving experience whereas divers and controls did not differ significantly with respect to age, anthropometric data, current smoking habits, skin prick reaction, and elevated serum IgE. Our results indicate an increased prevalence of AHR to nonspecific inhalation stimuli in experienced divers. Bronchial challenge tests may be helpful to detect asthmatics in the medical assessment of fitness to dive and for follow-up examinations during a diver's career. PMID:9730792

  6. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators...

  7. Integration of Wind Turbines with Compressed Air Energy Storage

    Science.gov (United States)

    Arsie, I.; Marano, V.; Rizzo, G.; Moran, M.

    2009-08-01

    Some of the major limitations of renewable energy sources are represented by their low power density and intermittent nature, largely depending upon local site and unpredictable weather conditions. These problems concur to increase the unit costs of wind power, so limiting their diffusion. By coupling storage systems with a wind farm, some of the major limitations of wind power, such as a low power density and an unpredictable nature, can be overcome. After an overview on storage systems, the Compressed Air Energy Storage (CAES) is analyzed, and the state of art on such systems is discussed. A Matlab/Simulink model of a hybrid power plant consisting of a wind farm coupled with CAES is then presented. The model has been successfully validated starting from the operating data of the McIntosh CAES Plant in Alabama. Time-series neural network-based wind speed forecasting are employed to determine the optimal daily operation strategy for the storage system. A detailed economic analysis has been carried out: investment and maintenance costs are estimated based on literature data, while operational costs and revenues are calculated according to energy market prices. As shown in the paper, the knowledge of the expected available energy is a key factor to optimize the management strategies of the proposed hybrid power plant, allowing to obtain environmental and economic benefits.

  8. Exergy Analysis of the Revolving Vane Compressed Air Engine

    Directory of Open Access Journals (Sweden)

    Alison Subiantoro

    2016-01-01

    Full Text Available Exergy analysis was applied to a revolving vane compressed air engine. The engine had a swept volume of 30 cm3. At the benchmark conditions, the suction pressure was 8 bar, the discharge pressure was 1 bar, and the operating speed was 3,000 rev·min−1. It was found that the engine had a second-law efficiency of 29.6% at the benchmark conditions. The contributors of exergy loss were friction (49%, throttling (38%, heat transfer (12%, and fluid mixing (1%. A parametric study was also conducted. The parameters to be examined were suction reservoir pressure (4 to 12 bar, operating speed (2,400 to 3,600 rev·min−1, and rotational cylinder inertia (0.94 to 2.81 g·mm2. The study found that a higher suction reservoir pressure initially increased the second-law efficiency but then plateaued at about 30%. With a higher operating speed and a higher cylinder inertia, second-law efficiency decreased. As compared to suction pressure and operating speed, cylinder inertia is the most practical and significant to be modified.

  9. Operability Test Report for 241-U Compressed Air System and heat pump

    International Nuclear Information System (INIS)

    The 241-U-701 compressed air system supplies instrument quality compressed air to Tank Farm 241-U. The system was upgraded. The operability test showed that the system operates within its intended design parameters. System performance was monitored, recorded, and used to identify areas of concern. Exceptions to the OTP and additional items for safe system performance were minimal and have been resolved; the air system is ready for Operation's use

  10. Firing with compressed air at very high pressure; Disparo con aire comprimido a muy alta presion

    Energy Technology Data Exchange (ETDEWEB)

    Saez Garcia, E.; Margareto Garcia, J.L.; Millan Echevarria, J.L.; Embil Martinez, E. [Escuela Tecnia Superior de Ingenieros Mineros, Oviedo (Spain)

    1994-05-01

    This article recounts the experiments executed in Hunosa`s Montsacro pit on the application of the DAMAP (Disparo can aire comprimido a muy alta presion - Firing with compressed air at very high pressure) process to the horizontal, sloping and caving seams or horizontal sublevels mining method usually used by Hunosa for thick and vertical seams. The project met the approval of Ocicarbon who participated with finance. Mescek Coal Mines also participated with their knowledge of DAMAP from mining in Hungary and provided the necessary equipment, technical assistance and training for Hunosa personnel. The project lasted for 14 months, comprising three phases: receipt, assembling of the equipment, and two months of system testing; 10 months of experiments to discern the possibilities offered by DAMAP technology in horizontal sublevels; and compilation of a report recounting the experience and results of the project. 3 figs., 1 tab.

  11. Optimization Study on a Single-cylinder Compressed Air Engine

    Institute of Scientific and Technical Information of China (English)

    YU Qihui; CAI Maolin; SHI Yan; XU Qiyue

    2015-01-01

    The current research of compressed air engine (CAE) mainly focused on simulations and system integrations. However, energy efficiency and output torque of the CAE is limited, which restricts its application and popularization. In this paper, the working principles of CAE are briefly introduced. To set a foundation for the study on the optimization of the CAE, the basic mathematical model of working processes is set up. A pressure-compensated valve which can reduce the inertia force of the valve is proposed. To verify the mathematical model, the prototype with the newly designed pressure-compensated intake valve is built and the experiment is carried out, simulation and experimental results of the CAE are conducted, and pressures inside the cylinder and output torque of the CAE are obtained. Orthogonal design and grey relation analysis are utilized to optimize structural parameters. The experimental and optimized results show that, first of all, pressure inside the cylinder has the same changing tendency in both simulation curve and experimental curve. Secondly, the highest average output torque is obtained at the highest intake pressure and the lowest rotate speed. Thirdly, the optimization of the single-cylinder CAE can improve the working efficiency from an original 21.95% to 50.1%, an overall increase of 28.15%, and the average output torque increases also increases from 22.047 5 N • m to 22.439 N • m. This research designs a single-cylinder CAE with pressure-compensated intake valve, and proposes a structural parameters design method which improves the single-cylinder CAE performance.

  12. Optimization study on a single-cylinder compressed air engine

    Science.gov (United States)

    Yu, Qihui; Cai, Maolin; Shi, Yan; Xu, Qiyue

    2015-11-01

    The current research of compressed air engine (CAE) mainly focused on simulations and system integrations. However, energy efficiency and output torque of the CAE is limited, which restricts its application and popularization. In this paper, the working principles of CAE are briefly introduced. To set a foundation for the study on the optimization of the CAE, the basic mathematical model of working processes is set up. A pressure-compensated valve which can reduce the inertia force of the valve is proposed. To verify the mathematical model, the prototype with the newly designed pressure-compensated intake valve is built and the experiment is carried out, simulation and experimental results of the CAE are conducted, and pressures inside the cylinder and output torque of the CAE are obtained. Orthogonal design and grey relation analysis are utilized to optimize structural parameters. The experimental and optimized results show that, first of all, pressure inside the cylinder has the same changing tendency in both simulation curve and experimental curve. Secondly, the highest average output torque is obtained at the highest intake pressure and the lowest rotate speed. Thirdly, the optimization of the single-cylinder CAE can improve the working efficiency from an original 21.95% to 50.1%, an overall increase of 28.15%, and the average output torque increases also increases from 22.047 5 N • m to 22.439 N • m. This research designs a single-cylinder CAE with pressure-compensated intake valve, and proposes a structural parameters design method which improves the single-cylinder CAE performance.

  13. Project of energy saving in compressed air; Proyecto de ahorro de energia en aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Automatizacion, Productividad y Calidad S.A. de C.V. Puebla, (Mexico)

    2005-07-01

    The objective of this project is to reduce the operation costs by means of the energy saving through the use of the compressed air system. For this purpose the solenoid valves controlled per time and the manually acted valves of sphere must be replaced by pneumatic purges that remove from the system the condensed humidity without discharging air and which act automatically when the water reaches the level of unloading in its deposit. The pressure level is the reduction of the operation rank of pressure in the compressors, satisfying the operation requirements of the process equipment. [Spanish] El objetivo de este proyecto es reducir el costo de operacion mediante el ahorro de energia en la utilizacion del sistema de aire comprimido. Para ello se tienen que remplazar las valvulas solenoides controladas por tiempo y valvulas de esfera actuadas manualmente por purgas neumaticas que remueven del sistema la humedad condensada sin descargar aire y que actuan en forma automatica al alcanzar el agua el nivel de descarga en su deposito. El nivel de presion es la reduccion del rango de operacion de presion de los compresores, satisfaciendo los requerimientos de operacion de los equipos de proceso.

  14. Operability Test Report for 241-T compressed air system and heat pump

    International Nuclear Information System (INIS)

    This Operability Test Report (OTR) documents the results of functional testing performed on the operating parameters of the 241-T-701 Compressed Air System. The System was successfully installed and tested per work package 2W-92-01172

  15. Effects of boundary layer and liquid viscosity and compressible air on sloshing characteristics

    Directory of Open Access Journals (Sweden)

    Zou Chang-Fang

    2015-07-01

    Full Text Available In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

  16. Effects of boundary layer and liquid viscosity and compressible air on sloshing characteristics

    Science.gov (United States)

    Zou, Chang-Fang; Wang, De-Yu; Cai, Zhong-Hua

    2015-07-01

    In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

  17. Methodology for the energy analysis of compressed air systems; Metodologia para analisis energetico de sistemas de aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, T.; Ambriz, J. J.; Romero, H. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1992-12-31

    In this paper a methodology for the diagnosis of compressed air systems, for the identification of the potential energy saving is presented. The methodology consists in detecting the largest number of possible ways of energy saving. For this purpose it is divided into three parts: 1. Compressed air generation. 2. Compressed air distribution. 3. Compressed air users. For each one of the parts, the type of information required to perform the diagnosis study, as well as the necessary measuring equipment needed, is indicated. Afterwards, the possible saving ways that can be found and the ones that can be feasible, are analyzed. [Espanol] En este trabajo se presenta una metodologia para diagnosticar sistemas de aire comprimido, para identificar los potenciales de ahorro de energia. La metodologia consiste en detectar el mayor numero de posibles medidas de ahorro, para lo cual se divide en tres partes: 1. Generacion de aire comprimido. 2. Distribucion del aire comprimido. 3 Usuarios de aire comprimido. Para cada una de las partes se indica el tipo de informacion requerida para realizar el estudio de diagnostico, asi como el uso de equipo necesario de medicion. Despues se analizan las posibles medidas de ahorro que se pueden encontrar y las que pueden ser viables.

  18. Canandaigua Wines: Compressed Air System Upgrade Saves Energy and Improves Performance at a Winery

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-03-01

    In June 2004, Canandaigua Wine Company (CWC) completed an upgrade project on the compressed air system at its winery in Lodi, California. Before the project, the winery depended on two compressors to satisfy its production requirements. Anticipating an expansion of its production capacity, the winery commissioned a review of the compressed air system by a U.S. Department of Energy (DOE) Qualifi ed AIRMaster+ Specialist at Atlas Copco Compressors, Inc.

  19. Health effects from air pollution - calculation prices; Sundhedseffekter af luftforurening - beregningspriser

    Energy Technology Data Exchange (ETDEWEB)

    Skou Andersen, Mikael; Seested Nielsen, Jytte; Borgen Soerensen, Peter [DMU, Afdeling for Systemanalyse, Roskilde (Denmark); Frohn, Lise Marie; Solvang Jensen, Steen; Hertel, Ole; Brandt, Joergen; Christensen, Jesper [DMU, Afdeling for Atmosfaerisk Miljoe, Roskilde (Denmark)

    2004-10-01

    The basic aim of research focusing on the accounting of external effects is to provide estimates for the possible benefits of environmental policy projects. There is a demand within the field of environmental economic analysis for evaluations and estimates of the economic benefits arising from pollution reductions. Where benefits arising out of reduced emissions of harmful substances are concerned, these can be estimated according to the avoided damage costs associated with negative pollution impacts. A scientifically based method designed for this purpose has been developed in the pan-European ExternE project via the EU research programmes. The ExternE project has been implemented with the aim of estimating monetary values for externalities attached to air pollution accruing from energy production and transport. For this purpose, complex model-based environmental impact estimations have been coupled with corresponding monetary valuations via the modelling tool, Ecosense. A problem arising in relation to Ecosense methodology has been that externalities are often of local nature - pollution impact depending on the particular locality of the emission and dispersal characteristics in the surrounding environment. Therefore, the economic estimation of the impacts of pollution is based on a location-specific modelling system. (BA)

  20. HEAT OF COMPRESSION AND OPPORTUNITY OF ITS USE FOR INCREASE OF EFFICIENCY OF AIR SEPARATION PLANTS

    OpenAIRE

    Лавренченко, Г. К.; Швец, С. Г.; Копытин, А. В.

    2015-01-01

    The analysis of possible directions useful utilization of heat of compression for production of the cold water in the heat-utilizing refrigerating machine and for organization heating vacuum regeneration of the adsorbent bloc of the desiccation and the purification of the air. Mark expediency of the application absorption lithium bromide refrigerating machines for organization preliminary cooling of the air in the air separation plant large productivity.

  1. Experimental Investigation on the Effect of Phase Change Materials on Compressed Air Expansion in CAES Plants

    OpenAIRE

    Beatrice Castellani; Andrea Presciutti; Mirko Filipponi; Andrea Nicolini; Federico Rossi

    2015-01-01

    The integration of renewable energy in the electrical grid is challenging due to the intermittent and non-programmable generated electric power and to the transmission of peak power levels. Several energy storage technologies have been studied to find a solution to these issues. In particular, compressed air energy storage (CAES) plants work by pumping and storing air into a vessel or in an underground cavern; then when energy is needed, the pressurized air is expanded in an expansion turbine...

  2. Assessment of socio-economic consequences of the Commission's thematic strategy for air pollution; Vurdering af de samfundsoekonomiske konsekvensr af Kommissionens temastrategi for luftforurening

    Energy Technology Data Exchange (ETDEWEB)

    Bach, H.; Skou Andersen, M.; Illerup, J.B.

    2006-06-15

    The Commission has presented a thematic strategy on air pollution and has completed an Impact Assessment, which describes the costs and benefits for the member states. The thematic strategy is to result in a revised air quality directive as well as a revised NEC-directive that determines maximum emissions for a number of air pollution components, the so-called emission ceilings. The air pollution components include sulphur dioxide (SO{sub 2}), nitrogen oxide (NO{sub X}), volatile organic compounds (NMVOC), ammonia (NH{sub 3}) and particulate matters (PM{sub 2,5}). The thematic strategy draws up targets for reductions of the Danish emissions for these components, which have to be met by 2020. These reductions will contribute to a lowering of PM{sub 2,5} concentrations both in Denmark and in neighbouring countries. The concentration of PM{sub 2,5} in the air includes both primary particles that come from emission of particles from e.g. incineration processes, and so-called secondary particles that are generated from emissions of NO{sub X}, SO{sub 2} and NH{sub 3}, and from releases from e.g. vegetation. A very large part of the secondary particles in the air in Denmark stems from emissions of these components in the rest of Europe. A very important condition for a reduction in the concentration of PM{sub 2,5} in the air is thus a reduction of the emissions of these components in all of Europe. (au)

  3. Experimental Investigation on the Performance of a Compressed-Air Driven Piston Engine

    Directory of Open Access Journals (Sweden)

    Chih-Jie Yu

    2013-03-01

    Full Text Available This study presents an experimental investigation of a piston engine driven by compressed air. The compressed air engine was a modified 100 cm3 internal combustion engine obtained from a motorcycle manufacturer. The experiments in this study used a test bench to examine the power performance and pressure/temperature variations of the compressed air engine at pressures ranging from 5 to 9 bar (absolute pressure. The engine was modified from a 4-stroke to a 2-stroke engine using a cam system driven by a crankshaft and the intake and exhaust valves have a small lift due to this modification. The highest power output of 0.95 kW was obtained at 9 bar and 1320 rpm. The highest torque of 9.99 N·m occurred at the same pressure, but at 465 rpm. The pressure-volume (P-V diagram shows that cylinder pressure gradually increases after the intake valve opens because of the limited lift movement of the intake valve. Similar situations occurred during the exhaust process, restricting the power output of the compressed air engine. The pressure and temperature variation of the air at engine inlet and outlet were recorded during the experiment. The outlet pressure increased from 1.5 bar at 500 rpm to 2.25 bar at 2000 rpm, showing the potential of recycling the compressed air energy by attaching additional cylinders (split-cycle engine. A temperature decrease (from room temperature to 17 °C inside the cylinder was observed. It should be noted that pressures higher than that currently employed can result in lower temperatures and this can cause poor lubrication and sealing issues. The current design of a compressed air engine, which uses a conventional cam mechanism for intake and exhaust, has limited lift movement during operation, and has a restricted flow rate and power output. Fast valve actuation and a large lift are essential for improving the performance of the current compressed air engine. This study presents a power output examination with the pressure

  4. LCA af genbrug af mursten

    DEFF Research Database (Denmark)

    Møller, Jacob; Damgaard, Anders; Astrup, Thomas Fruergaard

    Der er gennemført en livscyklusbaseret miljøvurdering af genbrug af mursten. Modelleringen er baseret på, hvordan Virksomheden ”Gamle Mursten” forbereder de gamle mursten med henblik på, at de kan genbruges i nybyggeri. Som alternativ til direkte genbrug nedknuses murstensaffaldet og anvendes som...... fyldmateriale ved anlægsarbejder. Under forudsætning af, at en genbrugt mursten teknisk og funktionelt erstatter en ny mursten, er genbrug i varierende grad en mere fordelagtig behandlingsmetode end genanvendelse i forhold til forskellige påvirkninger af miljøet....

  5. Failure Monitoring and Leakage Detection for Underground Storage of Compressed Air Energy in Lined Rock Caverns

    Science.gov (United States)

    Kim, Hyung-Mok; Rutqvist, Jonny; Kim, Hyunwoo; Park, Dohyun; Ryu, Dong-Woo; Park, Eui-Seob

    2016-02-01

    Underground compressed air energy storage (CAES) in lined rock caverns (LRCs) provides a promising solution for storing energy on a large scale. One of the essential issues facing underground CAES implementation is the risk of air leakage from the storage caverns. Compressed air may leak through an initial defect in the inner containment liner, such as imperfect welds and construction joints, or through structurally damaged points of the liner during CAES operation for repeated compression and decompression cycles. Detection of the air leakage and identification of the leakage location around the underground storage cavern are required. In this study, we analyzed the displacement (or strain) monitoring method to detect the mechanical failure of liners that provides major pathways of air leakage using a previously developed numerical technique simulating the coupled thermodynamic and geomechanical behavior of underground CAES in LRCs. We analyzed the use of pressure monitoring to detect air leakage and characterize the leakage location. From the simulation results, we demonstrated that tangential strain monitoring at the inner face of sealing liners could enable one to detect failure. We also demonstrated that the use of the cross-correlation method between pressure history data measured at various sensors could identify the air leak location. These results may help in the overall design of a monitoring and alarm system for the successful implementation and operation of CAES in LRCs.

  6. Performance Analysis of a Coal-Fired External Combustion Compressed Air Energy Storage System

    OpenAIRE

    Wenyi Liu; Qing Li; Feifei Liang; Linzhi Liu; Gang Xu; Yongping Yang

    2014-01-01

    Compressed air energy storage (CAES) is one of the large-scale energy storage technologies utilized to provide effective power peak load shaving. In this paper, a coal-fired external combustion CAES, which only uses coal as fuel, is proposed. Unlike the traditional CAES, the combustion chamber is substituted with an external combustion heater in which high-pressure air is heated before entering turbines to expand in the proposed system. A thermodynamic analysis of the proposed CAES is conduct...

  7. Evaluation of turbine systems for compressed air energy storage plants. Final report for FY 1976

    Energy Technology Data Exchange (ETDEWEB)

    Kartsounes, G.T.

    1976-10-01

    Compressed air energy storage plants for electric utility peak-shaving applications comprise four subsystems: a turbine system, compressor system, an underground air storage reservoir, and a motor/generator. Proposed plant designs use turbines that are derived from available gas and steam turbines with proven reliability. The study examines proposed turbine systems and presents an evaluation of possible systems that may reduce capital cost and/or improve performance. Six new turbine systems are identified for further economic evaluation.

  8. Thermodynamic impact of aquifer permeability on the performance of a compressed air energy storage plant

    International Nuclear Information System (INIS)

    Highlights: • Design procedure of an aquifer compressed air energy storage system was proposed. • An approach to select aquifers with adequate permeability was presented. • Applied an exergy analysis to exam the impact of permeability on plant economics. • The exergy destruction in the aquifer was reduced as the permeability increased. - Abstract: Economic, large-scale energy storage technology plays a key role in enabling the utility industry to integrate more renewable energy sources into the grid. Compressed air energy storage in porous geological formations has the potential to become one of the principal energy storage technologies in the future. Storing pressurized air in aquifers has several advantages, including large storage capacity, geologically widespread availability, relatively constant pressure, and relatively low construction cost. The performance of a compressed air energy storage plant is influenced by the subsurface reservoir properties. In this paper, the design criteria, calculation procedure, and exergy analysis approach to quantify the influence of aquifer permeability on compressed air energy storage plants are proposed. A case-study model was built to simulate a compressed air energy storage plant using aquifers with porosities of 30% and different permeabilities (0.01–1.0 darcies). The exergy destruction rates and exergy and thermal efficiencies were calculated. The results indicated that as the permeability increased, the exergy destruction due to a pressure drop of working fluid in an aquifer decreased; as the permeability increased, both thermal and exergy efficiencies increased, and the net output of the plant increased. The benefits are more obvious when the permeability increased from low (⩽0.05 darcies) to medium–high values (⩾0.25 darcies)

  9. Demonstration of Isothermal Compressed Air Energy Storage to Support Renewable Energy Production

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, Benjamin [Sustainx, Incorporated, Seabrook, NH (United States)

    2015-01-02

    This project develops and demonstrates a megawatt (MW)-scale Energy Storage System that employs compressed air as the storage medium. An isothermal compressed air energy storage (ICAESTM) system rated for 1 MW or more will be demonstrated in a full-scale prototype unit. Breakthrough cost-effectiveness will be achieved through the use of proprietary methods for isothermal gas cycling and staged gas expansion implemented using industrially mature, readily-available components.The ICAES approach uses an electrically driven mechanical system to raise air to high pressure for storage in low-cost pressure vessels, pipeline, or lined-rock cavern (LRC). This air is later expanded through the same mechanical system to drive the electric motor as a generator. The approach incorporates two key efficiency-enhancing innovations: (1) isothermal (constant temperature) gas cycling, which is achieved by mixing liquid with air (via spray or foam) to exchange heat with air undergoing compression or expansion; and (2) a novel, staged gas-expansion scheme that allows the drivetrain to operate at constant power while still allowing the stored gas to work over its entire pressure range. The ICAES system will be scalable, non-toxic, and cost-effective, making it suitable for firming renewables and for other grid applications.

  10. Effects Of Compressed Air Foam Application On Heat Conditions In Fire Within A Closed Space

    Directory of Open Access Journals (Sweden)

    Adam Thomitzek

    2016-01-01

    Full Text Available This article evaluates the knowledge obtained in firefighting tests using compressed air foam system (CAFS within a confined space. Six experiments were conducted for verification during the cooling of rooms and the self-extinguishing effect. The simulation was for a fully developed fire within a room. The fuel was chosen to simulate ordinary combustible materials utilized in residential areas. Mantel thermocouples were placed in the rooms to record the temperature changes. Compressed air foam was first applied with a standard fire hose nozzle to the ceiling and then to the epicenter of fire. Fire extinguishing was initiated after reaching the desired temperature in the room. The temperature for the start of fire extinguishing matched the third phase of development of a fire. Fire extinguishing was terminated after no obvious signs of fire were shown in epicenter of fire. The outputs of the experiments were evaluated on the basis of the amount of time passed for the temperature to drop below the suggested limit. Individual experiments were also conducted with various different admixing foaming agents over different locations. In the experiments, it has been verified that the application of compressed air foam has a positive effect on room cooling. Use of a compressed air foaming agent does not allow for the development of steam that can scald firefighters and reduce visibility. Furthermore, the extinguishing agent used is more efficient utilizing less water flow out of the fire area.

  11. The effect of compressed air massage on untraumatised rabbit skeletal muscle - a morphometric and ultrastructural study

    Directory of Open Access Journals (Sweden)

    M. A. Gregory

    2004-02-01

    Full Text Available One of the therapeutic uses of massage is to facilitate repairof damaged tissue. A potential hazard of massage is that direct pressure onmuscle is known to damage skeletal myofibres. This study examines theeffect of a new form of massage using compressed air on the morphology ofuntraumatised rabbit skeletal myofibres. Under anaesthetic, the left and right vastus lateralis muscles of 16 New Zealand, white rabbits were treated with 10 minutes of compressed air therapy at 1 Bar using a single hole (5 mm applicator head and control biopsies were taken from the opposite limb. Biopsies were prepared for light microscopy and transmission electronmicroscopy. Morphometry, using image analysis revealed a significant increase in myofibre diameters 10 minutes  (p < 0.001 and 24 hours (p<0.01 after compressed air massage. Six days after treatment diameters were significantly reduced (p < 0.01. Morphologically, myofibres in control specimens were normal. Shortly after compressed air  massage, juxta-nuclear and intermyofibrillar oedema was present and electron-lucent spaces were filled with swollen mitochondria and elements of the sarcoplasmic reticulum (SR. Glycogen and other non-contractile organelles were sometimes aggregated in oedematous, sub-sarcolemmal regions. Twenty four hours after treatment, intermyofibrillar oedema was reduced, but SR swelling remained and many fibres were characterised by focal and large areas of myofibrillar disorganisation. With the exception of occasional swollen elements of the SR and a single internalised nucleus, myofibres morphology had returned to normal 6 days after treatment. Compressed air massage causes less damage to skeletal myofibres than a similar form of localised pressure treatment, deep transverse frictions. Clinicalstudies using this new modality are warranted.

  12. Fremtidssikring af kloaknet

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2008-01-01

    Beskrivelse af hvordan man ved udbygning af eksisterende kloaknet og ved nytænkning af planlægning af nye bydele kan sikre sig langsigtet mod konsekvenserne af klimaændinger og kraftigere nedbør...

  13. Experimental investigations on performance of liquid desiccant-vapor compression hybrid air conditioner

    International Nuclear Information System (INIS)

    A coupled desiccant column is integrated with a conventional room air conditioner (AC) to enhance dehumidification of the room air. One desiccant column (absorber) is placed after the evaporator the other (regenerator) after the condenser of the AC unit. Such a novel liquid desiccant vapour compression hybrid air conditioning system has been fabricated and tested in a balanced ambient room type calorimeter for very low flow rates of liquid desiccant (lithium bromide solution). The moisture from the cold supply air is transferred to the hot condenser air by the desiccant flowing in the loop, thereby complimenting the dehumidification of the room air at the evaporator. The supply air is also sensibly heated during the dehumidification process by liquid desiccant in the absorber, which together enables the hybrid system to maintain low humidity in the room. Whereas the liquid desiccant is regenerated by the condenser waste heat, the entire cooling is derived only by the AC unit. The experimental results show that an increase of room temperature reduces both dehumidification of process air and regeneration of liquid desiccant, whereas an increase of room specific humidity enhances both these for the flow rate of the liquid desiccant in the range of 0.2–1.6% of the air flow rate through the absorber. - Highlights: • A liquid desiccant vapor compression hybrid system is fabricated and tested. • The liquid desiccant reduces latent load but equally increases sensible load. • Hybrid system performance is studied for varying room temperature and humidity. • Higher room temperature lowers air dehumidification and desiccant regeneration. • Increase of room specific humidity enhances dehumidification and also regeneration

  14. Compressed-air work is entering the field of high pressures.

    Science.gov (United States)

    Le Péchon, J Cl; Gourdon, G

    2010-01-01

    Since 1850, compressed-air work has been used to prevent shafts or tunnels under construction from flooding. Until the 1980s, workers were digging in compressed-air environments. Since the introduction of tunnel boring machines (TBMs), very little digging under pressure is needed. However, the wearing out of cutter-head tools requires inspection and repair. Compressed-air workers enter the pressurized working chamber only occasionally to perform such repairs. Pressures between 3.5 and 4.5 bar, that stand outside a reasonable range for air breathing, were reached by 2002. Offshore deep diving technology had to be adapted to TBM work. Several sites have used mixed gases: in Japan for deep shaft sinking (4.8 bar), in The Netherlands at Western Scheldt Tunnels (6.9 bar), in Russia for St. Petersburg Metro (5.8 bar) and in the United States at Seattle (5.8 bar). Several tunnel projects are in progress that may involve higher pressures: Hallandsås (Sweden) interventions in heliox saturation up to 13 bar, and Lake Mead (U.S.) interventions to about 12 bar (2010). Research on TBMs and grouting technologies tries to reduce the requirements for hyperbaric works. Adapted international rules, expertise and services for saturation work, shuttles and trained personnel matching industrial requirements are the challenges. PMID:20737925

  15. Compressed air energy storage with waste heat export: An Alberta case study

    International Nuclear Information System (INIS)

    Highlights: • Export of compression waste heat from CAES facilities for municipal heating can be profitable. • D-CAES concept has a negative abatement cost of −$40/tCO2e under the studied circumstances. • Economic viability of D-CAES highly depends on distance between air storage site and heat load. - Abstract: Interest in compressed air energy storage (CAES) technology has been renewed driven by the need to manage variability form rapidly growing wind and solar capacity. Distributed CAES (D-CAES) design aims to improve the efficiency of conventional CAES through locating the compressor near concentrated heating loads so capturing additional revenue through sales of compression waste heat. A pipeline transports compressed air to the storage facility and expander, co-located at some distance from the compressor. The economics of CAES are strongly dependant on electricity and gas markets in which they are embedded. As a case study, we evaluated the economics of two hypothetical merchant CAES and D-CAES facilities performing energy arbitrage in Alberta, Canada using market data from 2002 to 2011. The annual profit of the D-CAES plant was $1.3 million more on average at a distance of 50 km between the heat load and air storage sites. Superior economic and environmental performance of D-CAES led to a negative abatement cost of −$40/tCO2e. We performed a suite of sensitivity analyses to evaluate the impact of size of heat load, size of air storage, ratio of expander to compressor size, and length of pipeline on the economic feasibility of D-CAES

  16. A review on the recent development of solar absorption and vapour compression based hybrid air conditioning with low temperature storage

    Directory of Open Access Journals (Sweden)

    Noor D. N.

    2016-01-01

    Full Text Available Conventional air conditioners or vapour compression systems are main contributors to energy consumption in modern buildings. There are common environmental issues emanating from vapour compression system such as greenhouse gas emission and heat wastage. These problems can be reduced by adaptation of solar energy components to vapour compression system. However, intermittence input of daily solar radiation was the main issue of solar energy system. This paper presents the recent studies on hybrid air conditioning system. In addition, the basic vapour compression system and components involved in the solar air conditioning system are discussed. Introduction of low temperature storage can be an interactive solution and improved economically which portray different modes of operating strategies. Yet, very few studies have examined on optimal operating strategies of the hybrid system. Finally, the findings of this review will help suggest optimization of solar absorption and vapour compression based hybrid air conditioning system for future work while considering both economic and environmental factors.

  17. [Medical aspects of the environmental sanitation of workplaces in compressed air work in Japan].

    Science.gov (United States)

    Mano, Y; Shibayama, M

    1987-01-01

    Actual follow-up investigations were made for a period of 5 yr and 10 months since February 1980 on 55 places of caisson and shield work. The maximum bottom pressure in caisson work was 3.6 kg/cm2 (4.6 ATA) and that of shield work was 1.6 kg/cm2. The number of exposures of workers was 23,737 in caisson work and 75,244 in shield work. The items of geomedical measurements were temperature (degrees C), humidity, dust, illumination, noise, oxygen, carbonic acid gas and others. In compressed air work, it is most important to prevent decompression sickness (bends) from the view of occupational health. The incidence of bends has decreased in recent years because of strict control by regulations. Environmental hygiene, however, has seldom been discussed in this field and little geomedical control has been made on compressed air work. In view of this situation, we have, therefore, studied, observed, and measured the hygienic factors of this work during the past five years. This investigation is without doubt the first of its kind in Japan and the areas covered most of the regions where compressed air works have been made in the past. From these results, it can be concluded as follows: The working temperature was controlled, but humidity was too high (nearly 90%). Illumination was insufficient. Dust was a problem, but high humidity played an important role in decreasing the volume. The environment was noisy. It is therefore natural that environmental studies should be continued and hygienic consideration be further emphasized in compressed air work. PMID:3613254

  18. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    OpenAIRE

    Hanif SedighNejad; Tariq Iqbal; John Quaicoe

    2014-01-01

    In this paper a new concept for control and performance assessment of compressed air energy storage (CAES) systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI), measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated communit...

  19. Compressed Air Energy Storage: Optimal Performance and Techno-Economical Indices

    Directory of Open Access Journals (Sweden)

    Peter Vadasz

    1999-06-01

    Full Text Available A thermodynamic and techno-economical analysis of a Compressed Air Energy Storage system subjected to an exogenous periodic electricity price function of the interconnection is presented. The fundamental parameters affecting the thermodynamic performance and the techno-economical cost-benefit indices are identified and corresponding optimisation problems are formulated. The results of the analysis permit to obtain the optimal values of the fundamental plant parameters to be used in the design process.

  20. Factors affecting storage of compressed air in porous-rock reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Doherty, T.J.; Erikson, R.L.; Wiles, L.E.

    1983-05-01

    This report documents a review and evaluation of the geotechnical aspects of porous medium (aquifer) storage. These aspects include geologic, petrologic, geophysical, hydrologic, and geochemical characteristics of porous rock masses and their interactions with compressed air energy storage (CAES) operations. The primary objective is to present criteria categories for the design and stability of CAES in porous media (aquifers). The document will also describe analytical, laboratory, and field-scale investigations that have been conducted.

  1. Potential and Evolution of Compressed Air Energy Storage: Energy and Exergy Analyses

    OpenAIRE

    Young-Min Kim; Jang-Hee Lee; Seok-Joon Kim; Daniel Favrat

    2012-01-01

    Energy storage systems are increasingly gaining importance with regard to their role in achieving load levelling, especially for matching intermittent sources of renewable energy with customer demand, as well as for storing excess nuclear or thermal power during the daily cycle. Compressed air energy storage (CAES), with its high reliability, economic feasibility, and low environmental impact, is a promising method for large-scale energy storage. Although there are only two large-scale CAES p...

  2. Novel concepts of compressed air energy storage and thermo-electric energy storage

    OpenAIRE

    Kim, Young Min

    2012-01-01

    The interest in energy storage is currently increasing, especially from the perspectives of matching intermittent sources of renewable energy with customer demand and storing excess nuclear or thermal power during the daily cycle. Technologies to be considered for load leveling for large-scale energy systems, typically in the range of hours to days of discharge time, include pumped-storage hydroelectricity, compressed air energy storage (CAES), sodium sulfur (NaS) batteries, advanced absorben...

  3. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    Directory of Open Access Journals (Sweden)

    Dvořák Lukáš

    2015-01-01

    Full Text Available Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

  4. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    OpenAIRE

    Dvořák Lukáš; Fojtášek Kamil

    2015-01-01

    Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption expe...

  5. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    Science.gov (United States)

    Dvořák, Lukáš; Fojtášek, Kamil

    2015-05-01

    Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

  6. A Coupled Thermo-Hydro-Mechanical Model of Jointed Hard Rock for Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Xiaoying Zhuang

    2014-01-01

    Full Text Available Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.

  7. Optimization of the Starting by compressed air techniques; Optimizacion del Arranque en el sutiraje mediante tecnicas de aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    High-pressure compressed air shots have been begun to use for coal stop caving in horizontal sublevel caving workings, as alternative to explosives, since they do not condition the winning cycles and they produce a smaller deterioration in the vein walls. In spite of those advantages, different parameters influence on shot result is not known. For this reason, a research project has been carried out in order to improve the high-pressure compressed air technique to extend the system implementation and to reduce the winning costs in the sublevel caving workings. The research works have consisted of a numerical model development and reduced scale and real scale tests. The model describes fragile material fragmentation under dynamical loadings and it has been implemented in a code. The tests allow to study the different parameter influence and to validate the numerical model. The main research results are, on the one hand, a numerical model that allows to define the best shot plan for user's working conditions and, on the other hand, the great influence of the air volume on the disruptive strength has been proven. (Author)

  8. Pneumatic hybridization of a diesel engine using compressed air storage for wind-diesel energy generation

    International Nuclear Information System (INIS)

    In this paper, we are studying an innovative solution to reduce fuel consumption and production cost for electricity production by Diesel generators. The solution is particularly suitable for remote areas where the cost of energy is very high not only because of inherent cost of technology but also due to transportation costs. It has significant environmental benefits as the use of fossil fuels for electricity generation is a significant source of GHG (Greenhouse Gas) emissions. The use of hybrid systems that combine renewable sources, especially wind, and Diesel generators, reduces fuel consumption and operation cost and has environmental benefits. Adding a storage element to the hybrid system increases the penetration level of the renewable sources, that is the percentage of renewable energy in the overall production, and further improves fuel savings. In a previous work, we demonstrated that CAES (Compressed Air Energy Storage) has numerous advantages for hybrid wind-diesel systems due to its low cost, high power density and reliability. The pneumatic hybridization of the Diesel engine consists to introduce the CAES through the admission valve. We have proven that we can improve the combustion efficiency and therefore the fuel consumption by optimizing Air/Fuel ratio thanks to the CAES assistance. As a continuation of these previous analyses, we studied the effect of the intake pressure and temperature and the exhaust pressure on the thermodynamic cycle of the diesel engine and determined the values of these parameters that will optimize fuel consumption. -- Highlights: ► Fuel economy analysis of a simple pneumatic hybridization of the Diesel engine using stored compressed air. ► Thermodynamic analysis of the pneumatic hybridization of diesel engines for hybrid wind-diesel energy systems. ► Analysis of intake pressure and temperature of compressed air and exhaust pressure on pressure/temperature during Diesel thermodynamic cycle. ► Direct admission of

  9. Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

    KAUST Repository

    Li, Erqiang

    2015-09-07

    When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large enough to compress the air. Herein we use high-speed interferometry, with 200 ns time-resolution, to directly observe the thickness evolution of the air layer during the entire bubble entrapment process. The initial disc radius and thickness shows excellent agreement with available theoretical models, based on adiabatic compression. For the largest impact velocities the air is compressed by as much as a factor of 14. Immediately following the contact, the air disc shows rapid vertical expansion. The radial speed of the surface minima just before contact, can reach 50 times the impact velocity of the drop.

  10. Air quality assessment of low emission zones in Copenhagen. [Denmark]; Luftkvalitetsvurdering af ren-luftzone i Koebenhavn

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.; Ketzel, M.; Brandt, J.; Winther, M.; Ellermann, T.

    2012-09-15

    According to the government agreement from 2011 improved low emission zones have been identified as a measure to improve the air quality in greater Danish cities, and to ensure compliance with air quality limit values for NO{sub 2} of 40 {mu}g/m{sup 3} as an annual mean. The limit value is violated at H.C. Andersens Boulevard in Copenhagen which is one of the busiest urban streets in Denmark and a fixed air quality monitor station is also located in the street. Air quality model calculations also shows that some other busy streets in Copenhagen violate the annual air quality limit values for NO{sub 2}. The objective of the project is to assess the impacts of a number of improved low emission zone measures in Copenhagen regarding emissions and air quality with focus on NO{sub 2}. The impact assessment of different scenarios includes assessment of emissions and air quality. The assessment is carried out in great details for NO{sub 2} and to a lesser degree for PM exhaust, PM{sub 2.5} and PM{sub 10}. Since air quality assessment is resource demanding only the main scenarios are carried out with the full air quality model whereas the air quality of the scenario variants are assessed based on regression analysis between emissions and air quality in scenarios calculated with the full air quality model. (LN)

  11. Preliminary stability criteria for compressed air energy storage in porous media reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Stottlemyre, J.A.

    1978-06-01

    Results from the initial phase of a study to establish subsurface design and operating criteria for a Compressed Air Energy Storage (CAES) facility are summarized. The primary objective was to derive a preliminary set of criteria that would help ensure the long term (30 to 40 year) integrity of CAES reservoirs in porous media, such as aquifers or abandoned natural gas reservoirs. In addition, appropriate research and development tasks were to be defined if the current technology was found to be inadequate. Preliminary stability and design criteria for storage of compressed air in porous media were determined on the basis of a survey of the open literature and the experience of experts in industry and universities. The results were separated into two categories: criteria for low temperature air injection (under 200/sup 0/F) and criteria for high temperature air injection (200 to 650/sup 0/F). Results are presented as maximum and/or minimum bounds for a number of parameters such as porosity, permeability, closure, storage pressure, caprock thickness, delta pressure, and caprock slope. One of the prime conclusions derived from an evaluation of the low temperature concept is that the technology currently exists to handle the potential design and operating problems. Therefore, there appears to be no technical roadblocks to the successful demonstration of the CAES concept, and a pilot project could be constructed in the near future.

  12. Development of a dynamic centrifugal compressor selector for large compressed air networks in the mining industry / Johan Venter.

    OpenAIRE

    Venter, Johan

    2012-01-01

    Various commercial software packages are available for simulating compressed air network operations. However, none of these software packages are able to dynamically prioritise compressor selection on large compressed air networks in the mining industry. In this dissertation, a dynamic compressor selector (DCS) will be developed that will actively and continuously monitor system demand. The software will ensure that the most suitable compressors, based on efficiency and posi...

  13. Formstykker af papiruld

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2001-01-01

    Resume af rapport om formstykker af papiruld, udarbejdet af Miljø Isolering Aps under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"......Resume af rapport om formstykker af papiruld, udarbejdet af Miljø Isolering Aps under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  14. Anvendelse af alternative isoleringsmaterialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2003-01-01

    Resume af By og Byg Anvisning 207 om anvendelse af alternative isoleringsmaterialer, udarbejdet af Statens Byggeforskningsinstitut under udviklingsprogrammet "Miljø- og arbejdsmiljøvenlig isolering"......Resume af By og Byg Anvisning 207 om anvendelse af alternative isoleringsmaterialer, udarbejdet af Statens Byggeforskningsinstitut under udviklingsprogrammet "Miljø- og arbejdsmiljøvenlig isolering"...

  15. Gas turbine engine adapted for use in combination with an apparatus for separating a portion of oxygen from compressed air

    Science.gov (United States)

    Bland, Robert J.; Horazak, Dennis A.

    2012-03-06

    A gas turbine engine is provided comprising an outer shell, a compressor assembly, at least one combustor assembly, a turbine assembly and duct structure. The outer shell includes a compressor section, a combustor section, an intermediate section and a turbine section. The intermediate section includes at least one first opening and at least one second opening. The compressor assembly is located in the compressor section to define with the compressor section a compressor apparatus to compress air. The at least one combustor assembly is coupled to the combustor section to define with the combustor section a combustor apparatus. The turbine assembly is located in the turbine section to define with the turbine section a turbine apparatus. The duct structure is coupled to the intermediate section to receive at least a portion of the compressed air from the compressor apparatus through the at least one first opening in the intermediate section, pass the compressed air to an apparatus for separating a portion of oxygen from the compressed air to produced vitiated compressed air and return the vitiated compressed air to the intermediate section via the at least one second opening in the intermediate section.

  16. Comparative study of air conditioning systems with vapor compression chillers using the concept of green buildings

    Directory of Open Access Journals (Sweden)

    Gutenberg da Silva Pereira

    2015-10-01

    Full Text Available This paper sets out to compare two different cooling systems that use vapor compression chillers for air conditioning environments. It was proposed to compare different operations in isolated and combined action operations. These operations are evaluated in the concepts of green buildings. A mathematical model was developed based on the principles of mass and energy conservation and complemented by various functions so as to determine the thermophysical properties and efficiencies of the compressors. The equations of the model were solved by the EES (Engineering Equation Solver program. The model evaluates the influence of the main HVAC operating parameters of the chilled water system when operating under three different configurations. The results showed that the system with a differentiated compression presents a COP equal to that of the system with screw chillers in the range  0-300 RTs, and a COP hat is on average 9% higher in the range 400-800 RTs.

  17. Correlation reflectance spectroscopy of heterogeneous silver nanoparticle films upon compression at the air/water interface

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Gassin, Gaelle [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Harfouch, Yara El [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Benichou, Emmanuel [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Bachelier, Guillaume [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Russier-Antoine, Isabelle [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Jonin, Christian [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Roux, Stephane [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS 5260, Universite Claude Bernard Lyon 1, Batiment Claude Louis Berthollet, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Tillement, Olivier [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS 5260, Universite Claude Bernard Lyon 1, Batiment Claude Louis Berthollet, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Brevet, Pierre-Francois [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France)

    2008-02-06

    Alkanethiol passivated silver nanoparticles were spread at an air/water interface to form a single monolayer film. The surface pressure isotherms and the UV-visible absorbance spectra of the film were recorded as a function of compression, whereas the dynamic behaviour was investigated by reflectance correlation spectroscopy. The film is shown to be inhomogeneous, formed by domains of particles separated by large areas of low particle density. Two distinct motions were observed: Brownian diffusion of the domains and their translational flow due to convection. From the characteristic diffusion time of the domains, and using a Stokes-Einstein analysis, the domain size is determined as a function of surface compression. The domains start to form and grow once a fixed average particle density is reached. Above this density threshold, the attractive van der Waals forces between the particles are dominating compared with the repulsion forces due to the alkanethiol chains.

  18. Design issues for compressed air energy storage in sealed underground cavities

    Directory of Open Access Journals (Sweden)

    P. Perazzelli

    2016-06-01

    Full Text Available Compressed air energy storage (CAES systems represent a new technology for storing very large amount of energy. A peculiarity of the systems is that gas must be stored under a high pressure (p = 10–30 MPa. A lined rock cavern (LRC in the form of a tunnel or shaft can be used within this pressure range. The rock mass surrounding the opening resists the internal pressure and the lining ensures gas tightness. The present paper investigates the key aspects of technical feasibility of shallow LRC tunnels or shafts under a wide range of geotechnical conditions. Results show that the safety with respect to uplift failure of the rock mass is a necessary but not a sufficient condition for assessing feasibility. The deformation of the rock mass should also be kept sufficiently small to preserve the integrity of the lining and, especially, its tightness. If the rock is not sufficiently stiff, buckling or fatigue failure of the steel lining becomes more decisive when evaluating the feasible operating air pressure. The design of the concrete plug that seals the compressed air stored in the container is another demanding task. Numerical analyses indicate that in most cases, the stability of the rock mass under the plug loading is not a decisive factor for plug design.

  19. Improving Energy Efficiency in Pharmaceutical ManufacturingOperations -- Part I: Motors, Drives and Compressed Air Systems

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Chang, Sheng-chien; Worrell, Ernst; Masanet,Eric

    2006-04-01

    In Part I of this two-part series, we focus on efficient use of motors, drives and pumps, both for process equipment and compressed air systems. Pharmaceutical manufacturing plants in the U.S. spend nearly $1 billion each year for the fuel and electricity they need to keep their facilities running (Figure 1, below). That total that can increase dramatically when fuel supplies tighten and oil prices rise, as they did last year. Improving energy efficiency should be a strategic goal for any plant manager or manufacturing professional working in the drug industry today. Not only can energy efficiency reduce overall manufacturing costs, it usually reduces environmental emissions, establishing a strong foundation for a corporate greenhouse-gas-management program. For most pharmaceutical manufacturing plants, Heating, Ventilation and Air Conditioning (HVAC) is typically the largest consumer of energy, as shown in Table 1 below. This two-part series will examine energy use within pharmaceutical facilities, summarize best practices and examine potential savings and return on investment. In this first article, we will focus on efficient use of motors, drives and pumps, both for process equipment and compressed air systems. Part 2, to be published in May, will focus on overall HVAC systems, building management and boilers.

  20. Kvantificering af udledning af drivhusgasser fra affaldsbehandling

    OpenAIRE

    Mønster, Jacob; Scheutz, Charlotte; Kjeldsen, Peter

    2014-01-01

    Udledning af de stærke drivhusgasser metan og lattergas sker fra forskellige processer i behandlingen af affald. Eksempelvis kan affald, der bliver deponeret, danne metan, og behandlingen af spildevand kan danne lattergas og metan. Udledningen af drivhusgasser ender i atmosfæren og bidrager til den globale opvarmning, men størrelsen af disse udledninger er svær at bestemme grundet de store områder, hvorfra udledningen sker. I afhandlingen ”Kvantificering af udledning af drivhusgasser fra affa...

  1. Optimal operation strategies of compressed air energy storage (CAES) on electricity spot markets with fluctuating prices

    DEFF Research Database (Denmark)

    Lund, Henrik; Salgi, Georges; Elmegaard, Brian;

    2009-01-01

    Compressed air energy storage (CAES) technologies can be used for load levelling in the electricity supply and are therefore often considered for future energy systems with a high share of fluctuating renewable energy sources, such as e.g. wind power. In such systems, CAES plants will often operate...... on electricity spot markets by storing energy when electricity prices are low and producing electricity when prices are high. In order to make a profit on such markets, CAES plant operators have to identify proper strategies to decide when to sell and when to buy electricity. This paper describes...

  2. Air Pressurized Cabin Compressed Air Automatic Control System%空气加压氧舱压缩空气自动控制系统

    Institute of Scientific and Technical Information of China (English)

    郑志满; 张冕; 胡昕; 伍锡勇

    2011-01-01

    This paper describes a air pressurized cabin compressed air automatic control system, the designis simple, practical, safe and reliable.%本文介绍一种空气加压氧舱压缩空气自动控制系统,该设计简单、实用、安全、可靠.

  3. A Novel Pumped Hydro Combined with Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    Erren Yao

    2013-03-01

    Full Text Available A novel pumped hydro combined with compressed air energy storage (PHCA system is proposed in this paper to resolve the problems of bulk energy storage in the wind power generation industry over an area in China, which is characterised by drought and water shortages. Thermodynamic analysis of the energy storage system, which focuses on the pre-set pressure, storage volume capacity, water air volume ratio, pump performance, and water turbine performance of the storage system, is also presented. This paper discovers how such parameters affect the performance of the whole system. The ideal performance of this novel system has the following advantages: a simple, highly effective and low cost structure, which is comparable to the efficiency of a traditional pumped hydro storage system. Research results show a great solution to the current storage constraints encountered in the development of the wind power industry in China, which have been widely recognised as a bottleneck in the wind energy storage industry.

  4. The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock

    Directory of Open Access Journals (Sweden)

    Hehua Zhu

    2015-01-01

    Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.

  5. Destratification of an impounding reservoir using compressed air??case of Mudi reservoir, Blantyre, Malawi

    Science.gov (United States)

    Chipofya, V. H.; Matapa, E. J.

    This paper reviews the operational and cost effectiveness of a compressed air destratification system that was installed in the Mudi reservoir for destratifying the reservoir. Mudi reservoir is a raw water source for the Blantyre Water Board. It has a capacity of 1,400,000 cubic metres. The reservoir is 15.3 m deep at top water level. In the absence of any artificial circulation of air, the reservoir stratifies into two layers. There is a warm epilimnion in the top 3 m of the reservoir, with temperatures ranging from 23 to 26 °C. There is prolific algal growth in this layer. The bottom layer has much lower temperatures, and is oxygen deficient. Under such anaerobic conditions, ammonia, sulphides, iron and manganese are released from the sediments of the reservoir. As a result of nutrient inflow from the catchments, coupled with tropical ambient temperatures, the reservoir is most times infested with blue-green algae. This results into water treatment problems in respect of taste and odour and iron and manganese soluble salts. To abate such problems, air is artificially circulated in the reservoir, near the intake tower, through a perforated pipe that is connected to an electrically driven compressor. This causes artificial circulation of water in the hypolimnion region of the reservoir. As a result of this circulation, a hostile environment that inhibits the propagation of algae is created. Dissolved oxygen and temperature profiles are practically uniform from top to bottom of reservoir. Concentrations of iron and manganese soluble salts are much reduced at any of the draw-off points available for the water treatment process. The paper concludes by highlighting the significant cost savings in water treatment that are accrued from the use of compressed air destratification in impounding water storage reservoirs for the control of algae and other chemical pollutants.

  6. A Novel Constant-Pressure Pumped Hydro Combined with Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    Erren Yao

    2014-12-01

    Full Text Available As intermittent renewable energy is receiving increasing attention, the combination of intermittent renewable energy with large-scale energy storage technology is considered as an important technological approach for the wider application of wind power and solar energy. Pumped hydro combined with compressed air energy storage system (PHCA is one of the energy storage systems that not only integrates the advantages but also overcomes the disadvantages of compressed air energy storage (CAES systems and pumped hydro energy storage systems to solve the problem of energy storage in China’s arid regions. Aiming at the variable working conditions of PHCA system technology, this study proposes a new constant-pressure PHCA. The most significant characteristics of this system were that the water pump and hydroturbine work under stable conditions and this improves the working efficiency of the equipment without incurring an energy loss. In addition, the constant-pressure PHCA system was subjected to energy and exergy analysis, in expectation of exploring an attractive solution for the large-scale storage of existing intermittent renewable energy.

  7. Factors that influence the tribocharging of pulverulent materials in compressed-air devices

    International Nuclear Information System (INIS)

    Tribocharging of pulverulent materials in compressed-air devices is a typical multi-factorial process. This paper aims at demonstrating the interest of using the design of experiments methodology in association with virtual instrumentation for quantifying the effects of various process varaibles and of their interactions, as a prerequisite for the development of new tribocharging devices for industrial applications. The study is focused on the tribocharging of PVC powders in compressed-air devices similar to those employed in electrostatic painting. A classical 2 full-factorial design (3 factors at two levels) was employed for conducting the experiments. The response function was the charge/mass ratio of the material collected in a modified Faraday cage, at the exit of the tribocharging device. The charge/mass ratio was found to increase with the injection pressure and the vortex pressure in the tribocharging device, and to decrease with the increasing of the feed rate. In the present study an in-house design of experiments software was employed for statistical analysis of experimental data and validation of the experimental model.

  8. Potential and Evolution of Compressed Air Energy Storage: Energy and Exergy Analyses

    Directory of Open Access Journals (Sweden)

    Young-Min Kim

    2012-08-01

    Full Text Available Energy storage systems are increasingly gaining importance with regard to their role in achieving load levelling, especially for matching intermittent sources of renewable energy with customer demand, as well as for storing excess nuclear or thermal power during the daily cycle. Compressed air energy storage (CAES, with its high reliability, economic feasibility, and low environmental impact, is a promising method for large-scale energy storage. Although there are only two large-scale CAES plants in existence, recently, a number of CAES projects have been initiated around the world, and some innovative concepts of CAES have been proposed. Existing CAES plants have some disadvantages such as energy loss due to dissipation of heat of compression, use of fossil fuels, and dependence on geological formations. This paper reviews the main drawbacks of the existing CAES systems and presents some innovative concepts of CAES, such as adiabatic CAES, isothermal CAES, micro-CAES combined with air-cycle heating and cooling, and constant-pressure CAES combined with pumped hydro storage that can address such problems and widen the scope of CAES applications, by energy and exergy analyses. These analyses greatly help us to understand the characteristics of each CAES system and compare different CAES systems.

  9. Analysis and Optimization of a Compressed Air Energy Storage—Combined Cycle System

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-06-01

    Full Text Available Compressed air energy storage (CAES is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. This study proposes a CAES-CC system, which is based on a conventional CAES combined with a steam turbine cycle by waste heat boiler. Simulation and thermodynamic analysis are carried out on the proposed CAES-CC system. The electricity and heating rates of the proposed CAES-CC system are lower than those of the conventional CAES by 0.127 kWh/kWh and 0.338 kWh/kWh, respectively, because the CAES-CC system recycles high-temperature turbine-exhausting air. The overall efficiency of the CAES-CC system is improved by approximately 10% compared with that of the conventional CAES. In the CAES-CC system, compressing intercooler heat can keep the steam turbine on hot standby, thus improving the flexibility of CAES-CC. This study brought about a new method for improving the efficiency of CAES and provided new thoughts for integrating CAES with other electricity-generating modes.

  10. A Novel Hybrid-Fuel Storage System of Compressed Air Energy for China

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-08-01

    Full Text Available Compressed air energy storage (CAES is a large-scale technology that provides long-duration energy storage. It is promising for balancing the large-scale penetration of intermittent and dispersed sources of power, such as wind and solar power, into electric grids. The existing CAES plants utilize natural gas (NG as fuel. However, China is rich in coal but is deficient in NG; therefore, a hybrid-fuel CAES is proposed and analyzed in this study. Based on the existing CAES plants, the hybrid-fuel CAES incorporates an external combustion heater into the power generation subsystem to heat the air from the recuperator and the air from the high-pressure air turbine. Coal is the fuel for the external combustion heater. The overall efficiency and exergy efficiency of the hybrid-fuel CAES are 61.18% and 59.84%, respectively. Given the same parameters, the cost of electricity (COE of the hybrid-fuel CAES, which requires less NG, is $5.48/MW∙h less than that of the gas-fuel CAES. Although the proposed CAES requires a relatively high investment in the current electricity system in North China, the proposed CAES will be likely to become competitive in the market, provided that the energy supplies are improved and the large scale grid-connection of wind power is realized.

  11. Feasibility study of a hybrid wind turbine system – Integration with compressed air energy storage

    International Nuclear Information System (INIS)

    Highlights: • A new hybrid wind turbine system is proposed and feasibility study if conducted. • A complete mathematical model is developed and implemented in a software environment. • Multi-mode control strategy is investigated to ensure the system work smoothly and efficiently. • A prototype for implementing the proposed mechanism is built and tested as proof of the concept. • The proposed system is proved to be technically feasible with energy efficiency around 50%. - Abstract: Wind has been recognized as one of major realistic clean energy sources for power generation to meet the continuously increased energy demand and to achieve the carbon emission reduction targets. However, the utilisation of wind energy encounters an inevitable challenge resulting from the nature of wind intermittency. To address this, the paper presents the recent research work at Warwick on the feasibility study of a new hybrid system by integrating a wind turbine with compressed air energy storage. A mechanical transmission mechanism is designed and implemented for power integration within the hybrid system. A scroll expander is adopted to serve as an “air-machinery energy converter”, which can transmit additional driving power generalized from the stored compressed air to the turbine shaft for smoothing the wind power fluctuation. A mathematical model for the complete hybrid process is developed and the control strategy is investigated for corresponding cooperative operations. A prototype test rig for implementing the proposed mechanism is built for proof of the concept. From the simulated and experimental studies, the energy conversion efficiency analysis is conducted while the system experiences different operation conditions and modes. It is proved that the proposed hybrid wind turbine system is feasible technically

  12. Experimental investigation on a solid desiccant system integrated with a R407C compression air conditioner

    International Nuclear Information System (INIS)

    In the present work, experimental performance data of a solid desiccant based hybrid air conditioning system are presented. The system consists of a packed bed solid desiccant integrated with a R407C conventional vapor compression refrigeration system. Experiments are carried out during dehumidification operation mode for various operating parameters such as; desiccant mass on shelves (5, 10 and 15 kg), air mass flow rate (7.4 and 10.2 kg/min), shelves number (1, 2 and 3) and three values of shelves span (7, 14 and 28 cm) at evaporator air inlet conditions of 28 deg. C DBT and 66% RH, condenser air inlet volume flow rate of 850 m3/h and temperature of 35 deg. C. The reactivation of the desiccant at different regeneration temperatures and air flow rates as well as desiccant masses is also investigated. During the dehumidification mode, the average system coefficient of performance increases by 6.2% and 1.61% when the mass of desiccant increases from 5 to 10 kg and from 10 to 15 kg, respectively. The enhancement in the coefficient of performance is 6.2% due to increasing the air mass flow rate from 7.4 to 10.2 kg/min. Increasing both shelves number and span yields to a reduction in the adsorption rate that can be extracted by the desiccant material in the ranges of considered operating conditions. The regeneration temperature and the air flow rate of regeneration have significant effects on the reactivation process. It was found that, with increasing the mass flow rate of regenerated air from 7.4 to 10.2 kg/min produces a reduction in regeneration time by 87.5% and an augmentation in the desorption rate by 16% after 10 min of regeneration. In addition, with escalating the regeneration temperature from 45 to 55 deg. C, the reactivation time reduces by 25%. Reported results revealed that solid desiccant based hybrid air conditioning system reduces the compressor electric power and the number of electric unit (kW h) by 10.2%.

  13. Experimental investigation on a solid desiccant system integrated with a R407C compression air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Fatouh, M.; Mostafa, A. [Dept. of Mechanical Power Engineering, Faculty of Engineering, El-Mattaria (Helwan Univ.), Masaken El-Helmia P.O., Cairo 11718 (Egypt); Ibrahim, Talaat A. [Dept. of Mechanical Power Engineering, Faculty of Engineering, El-Mattaria (Helwan Univ.), Masaken El-Helmia P.O., Cairo 11718 (Egypt); King Saud Univ., P.O. 70908, 11577 Riyadh (Saudi Arabia)

    2009-10-15

    In the present work, experimental performance data of a solid desiccant based hybrid air conditioning system are presented. The system consists of a packed bed solid desiccant integrated with a R407C conventional vapor compression refrigeration system. Experiments are carried out during dehumidification operation mode for various operating parameters such as; desiccant mass on shelves (5, 10 and 15 kg), air mass flow rate (7.4 and 10.2 kg/min), shelves number (1, 2 and 3) and three values of shelves span (7, 14 and 28 cm) at evaporator air inlet conditions of 28 C DBT and 66% RH, condenser air inlet volume flow rate of 850 m{sup 3}/h and temperature of 35 C. The reactivation of the desiccant at different regeneration temperatures and air flow rates as well as desiccant masses is also investigated. During the dehumidification mode, the average system coefficient of performance increases by 6.2% and 1.61% when the mass of desiccant increases from 5 to 10 kg and from 10 to 15 kg, respectively. The enhancement in the coefficient of performance is 6.2% due to increasing the air mass flow rate from 7.4 to 10.2 kg/min. Increasing both shelves number and span yields to a reduction in the adsorption rate that can be extracted by the desiccant material in the ranges of considered operating conditions. The regeneration temperature and the air flow rate of regeneration have significant effects on the reactivation process. It was found that, with increasing the mass flow rate of regenerated air from 7.4 to 10.2 kg/min produces a reduction in regeneration time by 87.5% and an augmentation in the desorption rate by 16% after 10 min of regeneration. In addition, with escalating the regeneration temperature from 45 to 55 C, the reactivation time reduces by 25%. Reported results revealed that solid desiccant based hybrid air conditioning system reduces the compressor electric power and the number of electric unit (kW h) by 10.2%. (author)

  14. Avancering af maksillen ved brug af osseodistraktion

    DEFF Research Database (Denmark)

    Andersen, Kristian; Svenstrup, M; Nørholt, Sven Erik;

    2010-01-01

    Formålet med denne litteraturgennemgang er at danne en oversigt over foreliggende videnskabelig litteratur inden for emnet anvendelse af distraktionsosteogenese til ændring af maksillens position. Materialer og metoder – I artiklen gennemgås behandlingssekvens og typer af distraktionsudstyr....... Gennemgangen omfatter emnerne: 1) stabilitet og recidiv, 2) peroperativ og postoperativ morbiditet samt gener, 3) ændringer af blødtvæv under distraktion, 4) ændringer af velopharynx og taleevne samt 5) psykosociale effekter af behandlingen. Resultater – De eksisterende artikler har samlet set generelle...... metodologiske begrænsninger, hvorfor evidensniveauet i den nuværende videnskabelige litteratur er begrænset. Et enkelt studie viser en postoperativ mere stabil position af maksillen efter distraktionsosteogenese (DO). For de to typer af behandlinger er morbiditetsraten ens, mens morbiditetstyperne varierer. Der...

  15. Restaurering af Skjern Å

    DEFF Research Database (Denmark)

    Jessen, K.; Boysen Larsen, B.; Bundgaard, P.;

    Denne rapport indeholder resultaterne af den natur- og miljøovervågning, der blev iværksat som en del af naturgenopretningen af Skjern Å 1999-2002. Ved projektet ophørte den kunstige afvanding af den vestlige del af Skjern Å dalen. Størstedelen af de dyrkede arealer ændredes til ekstensive græsni...

  16. Metodeforbedring af Papiruldsisolering

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2002-01-01

    Resume afrapport om udvikling af en forbedret metide til fremstilling af papiruldsisolering,udarbejdet af tømrermester Henning Baadsmand under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"......Resume afrapport om udvikling af en forbedret metide til fremstilling af papiruldsisolering,udarbejdet af tømrermester Henning Baadsmand under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  17. Stability and design criteria studies for compressed air energy storage reservoirs. Progress report, FY 1977.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.C.; Stottlemyre, J.A.; Wiles, L.E.; Loscutoff, W.V.; Pincus, H.J.

    1978-03-01

    Progress made during FY-1977 in establishing design criteria to ensure the successful operation and long-term stability of Compressed Air Energy Storage (CAES) reservoirs in underground porous media, such as aquifers is summarized. The formulation of pertinent criteria is important since the long-term stability of air storage reservoirs is probably the item of greatest risk to the successful demonstration and commercialization of the CAES concept. The study has been divided into four phases: (1) state-of-the-art survey, (2) analytical modeling studies, (3) laboratory studies, and (4) field testing. The first of these phases, the state-of-the-art survey for air storage in porous reservoirs, has been completed on schedule and is reported in Section 2. Sections 3 and 4 are progress reports on Phases 2 and 3. No work has been done on Phase 4. It is planned that the field testing phase of this study will be carried out in conjunction with the Department of Energy/Electric Power Research Institute (DOE/EPRI) CAES Demonstration Program. This phase is not scheduled to begin until FY-1979.

  18. Adiabatic Compressed Air Energy Storage with packed bed thermal energy storage

    International Nuclear Information System (INIS)

    Highlights: • The paper presents a thermodynamic analysis of A-CAES using packed bed regenerators. • The packed beds are used to store the compression heat. • A numerical model is developed, validated and used to simulate system operation. • The simulated efficiencies are between 70.5% and 71.1% for continuous operation. • Heat build-up in the beds reduces continuous cycle efficiency slightly. - Abstract: The majority of articles on Adiabatic Compressed Air Energy Storage (A-CAES) so far have focussed on the use of indirect-contact heat exchangers and a thermal fluid in which to store the compression heat. While packed beds have been suggested, a detailed analysis of A-CAES with packed beds is lacking in the available literature. This paper presents such an analysis. We develop a numerical model of an A-CAES system with packed beds and validate it against analytical solutions. Our results suggest that an efficiency in excess of 70% should be achievable, which is higher than many of the previous estimates for A-CAES systems using indirect-contact heat exchangers. We carry out an exergy analysis for a single charge–storage–discharge cycle to see where the main losses are likely to transpire and we find that the main losses occur in the compressors and expanders (accounting for nearly 20% of the work input) rather than in the packed beds. The system is then simulated for continuous cycling and it is found that the build-up of leftover heat from previous cycles in the packed beds results in higher steady state temperature profiles of the packed beds. This leads to a small reduction (<0.5%) in efficiency for continuous operation

  19. Air MEDEVAC in case of multiple casualties – The experience of civilian-military cooperation in RoAF

    Directory of Open Access Journals (Sweden)

    Dragoș C. Tudose

    2016-07-01

    Full Text Available Introduction: Starting September 2010 in Romania was created the Military Emergency Medical Service (SMMU by the Ministry of National Defense, which has as main mission to provide first aid and save the lives of military personnel during military operations using special equipped MEDEAVC aircraft. Nationwide exist the national emergency system which operates thru 112- SMURD acting in support of the civilian population. In case of accidents with multiple victims the experience has shown the need for collaboration between the two systems, in order to save lives. In the last 5 years there has been an increasing Airlift missions (MEDEVAC with multiple victims executed by joint civil-military medical teams using military aircraft. Material and methods. This paper provides a review of the most important aspects of particularities, advantages and disadvantages of this type of medical transport using the MEDEVAC missions based study carried out by the Air Force in recent years. Results and conclusions. Performing these tasks presents challenges to mission planning, use of medical equipment and procedures, command-control system, exercise programs jointly joint medical teams and, of course, managing a large number of patients in flight. The large number of patients transported safely and in the shortest time, regardless of weather conditions recommends this type of medical intervention. Given the Romanian military presence in various theaters and that NATO strategic medical evacuation is a national responsibility, the capacity of air transport in case multiple casualties is a priority.

  20. Technology assessment report for the Soyland Power Cooperative, Inc. compressed air energy storage system (CAES)

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    The design and operational features of compressed air energy storage systems (CAES) in general and, specifically, of a proposed 220 MW plant being planned by the Soyland Power Cooperative, Inc. in Illinois are described. This technology assessment discusses the need for peaking capacity, CAES requirements for land, fuel, water, and storage caverns, and compares the costs, environmental impacts and licensing requirements of CAES with those of power plants using simple cycle or combined cycle combustion turbines. It is concluded that during the initial two years of CAES operation, the CAES would cost more than a combustion turbine or combined cycle facility, but thereafter the CAES would have a increasing economic advantage; the overall environmental impact of a CAES plant is minimal, and that there should be no great difficulties with CAES licensing. (LCL)

  1. Thermal System Analysis and Optimization of Large-Scale Compressed Air Energy Storage (CAES

    Directory of Open Access Journals (Sweden)

    Zhongguang Fu

    2015-08-01

    Full Text Available As an important solution to issues regarding peak load and renewable energy resources on grids, large-scale compressed air energy storage (CAES power generation technology has recently become a popular research topic in the area of large-scale industrial energy storage. At present, the combination of high-expansion ratio turbines with advanced gas turbine technology is an important breakthrough in energy storage technology. In this study, a new gas turbine power generation system is coupled with current CAES technology. Moreover, a thermodynamic cycle system is optimized by calculating for the parameters of a thermodynamic system. Results show that the thermal efficiency of the new system increases by at least 5% over that of the existing system.

  2. Experimental study on fire extinguishing with a newly prepared multi-component compressed air foam

    Institute of Scientific and Technical Information of China (English)

    WANG XiShi; LIAO YaoJian; LIN Lin

    2009-01-01

    A multi-component compressed air foam system (MCAFS) was developed with newly prepared multi-component foaming agents. Extinguishing of wood crib and oil pool fires was performed under different conditions, such as foam concentration, mixing chamber forepart structure and working pressure. It was found that the foam concentration had sufficient effects on fire extinguishing efficiency, and an optimized concentration value exists. For instance, for diesel oil pool fires, this value is about 2.2% while it is about 4.0% for wood crib fires. The results also show that the system with a coaxial mixing chamber has greater efficiency than a T-shape. The effects of working pressure on fire extin-guishing are evident in experiments, i.e., the higher the working pressure is, the more readily the fire is extinguished.

  3. Relevance of postmortem radiology to the diagnosis of fatal cerebral gas embolism from compressed air diving

    Science.gov (United States)

    Cole, A J; Griffiths, D; Lavender, S; Summers, P; Rich, K

    2006-01-01

    Aims To test the hypothesis that artefact caused by postmortem off‐gassing is at least partly responsible for the presence of gas within the vascular system and tissues of the cadaver following death associated with compressed air diving. Methods Controlled experiment sacrificing sheep after a period of simulated diving in a hyperbaric chamber and carrying out sequential postmortem computed tomography (CT) on the cadavers. Results All the subject sheep developed significant quantities of gas in the vascular system within 24 hours, as demonstrated by CT and necropsy, while the control animals did not. Conclusions The presence of gas in the vascular system of human cadavers following diving associated fatalities is to be expected, and is not necessarily connected with gas embolism following pulmonary barotrauma, as has previously been claimed. PMID:16489175

  4. Compressed air energy storage system reservoir size for a wind energy baseload power plant

    Energy Technology Data Exchange (ETDEWEB)

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload resource using an oversized wind farm in conjunction with a compressed air energy storage (CAES) system. The size of the storage reservoir for the CAES system (solution mined salt cavern or porous media) as a function of the wind speed autocorrelation time (C) has been examined using a Monte Carlo simulation for a wind class 4 (wind power density 450 W m{sup -2} at 50 m hub height) wind regime with a Weibull k factor of 2.5. For values of C typically found for winds over the US Great Plains, the storage reservoir must have a 60 to 80 hour capacity. Since underground reservoirs account for only a small fraction of total system cost, this larger storage reservoir has a negligible effect on the cost of energy from the wind energy baseload system. 7 refs., 2 figs., 1 tab.

  5. Slow Dynamics Model of Compressed Air Energy Storage and Battery Storage Technologies for Automatic Generation Control

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Venkat; Das, Trishna

    2016-05-01

    Increasing variable generation penetration and the consequent increase in short-term variability makes energy storage technologies look attractive, especially in the ancillary market for providing frequency regulation services. This paper presents slow dynamics model for compressed air energy storage and battery storage technologies that can be used in automatic generation control studies to assess the system frequency response and quantify the benefits from storage technologies in providing regulation service. The paper also represents the slow dynamics model of the power system integrated with storage technologies in a complete state space form. The storage technologies have been integrated to the IEEE 24 bus system with single area, and a comparative study of various solution strategies including transmission enhancement and combustion turbine have been performed in terms of generation cycling and frequency response performance metrics.

  6. A DETAILED EXPERIMENTAL INVESTIGATION ON HOT AIR ASSISTED TURPENTINE DIRECT INJECTED COMPRESSION IGNITION ENGINE

    Directory of Open Access Journals (Sweden)

    KARTHIKEYAN.R,

    2010-10-01

    Full Text Available In the present investigation, a diesel engine modified for turpentine direct injection (TDI has been tested to study turpentine oil behavior in compression ignition engine. Since, turpentine possesses low cetane number fails to auto ignite while DI. Hence, the test engine was modified to supply hot air during suction stroke, whichhelps to auto-ignite the injected turpentine. The engine with this facility was operated using turpentine under various load conditions and at various intake temperatures. The results of the investigation were proved that turpentine could be direct injectable in a regular diesel engine after little engine modification. This method showed almost same BTE at full load compared to standard diesel operation. Except NOx emission other emissions were found closer to diesel baseline operation. This mode offered almost 50% smoke free operation at all loads compared to standard diesel operation. Also, this method successfully proved the complete replacement of diesel fuel by turpentine oil.

  7. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    Directory of Open Access Journals (Sweden)

    Hanif SedighNejad

    2014-01-01

    Full Text Available In this paper a new concept for control and performance assessment of compressed air energy storage (CAES systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI, measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated community with significant wind energy resource. A case study reveals the usefulness of the proposed criterion in design, control and implementation of a small CAES system in a hybrid power system (HPM for an isolated community. Energy harvested index and its effectiveness in increasing the wind penetration rate in the total energy production is discussed.

  8. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    Directory of Open Access Journals (Sweden)

    Nicolas Craquelin

    2010-12-01

    Full Text Available We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  9. Modeling of coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in lined rock caverns

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, J.; Kim, H. -M.; Ryu, D. -W.; Synn, J. -H.; Song, W. -K.

    2012-02-01

    We applied coupled nonisothermal, multiphase fluid flow and geomechanical numerical modeling to study the coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in concrete-lined rock caverns. The paper focuses on CAES in lined caverns at relatively shallow depth (e.g., 100 m depth) in which a typical CAES operational pressure of 5 to 8 MPa is significantly higher than both ambient fluid pressure and in situ stress. We simulated a storage operation that included cyclic compression and decompression of air in the cavern, and investigated how pressure, temperature and stress evolve over several months of operation. We analyzed two different lining options, both with a 50 cm thick low permeability concrete lining, but in one case with an internal synthetic seal such as steel or rubber. For our simulated CAES system, the thermodynamic analysis showed that 96.7% of the energy injected during compression could be recovered during subsequent decompression, while 3.3% of the energy was lost by heat conduction to the surrounding media. Our geomechanical analysis showed that tensile effective stresses as high as 8 MPa could develop in the lining as a result of the air pressure exerted on the inner surface of the lining, whereas thermal stresses were relatively smaller and compressive. With the option of an internal synthetic seal, the maximum effective tensile stress was reduced from 8 to 5 MPa, but was still in substantial tension. We performed one simulation in which the tensile tangential stresses resulted in radial cracks and air leakage though the lining. This air leakage, however, was minor (about 0.16% of the air mass loss from one daily compression) in terms of CAES operational efficiency, and did not significantly impact the overall energy balance of the system. However, despite being minor in terms of energy balance, the air leakage resulted in a distinct pressure increase in the surrounding rock that could be

  10. A low-cost hybrid drivetrain concept based on compressed air energy storage

    International Nuclear Information System (INIS)

    Highlights: • A new pneumatic hybrid concept is introduced. • A proof-of-concept prototype system is built and tested. • The experimental system has a round-trip efficiency of just under 10%. • A thermodynamics model is used to predict the performance of modified designs. • An efficiency of nearly 50% is possible with reasonable design changes. - Abstract: This paper introduces a new low-cost hybrid drivetrain concept based on compressed air energy storage. In contrast to most contemporary approaches to pneumatic hybridization, which require modification to the primary power plant, this concept is based on a stand-alone pneumatic system that could be readily integrated with existing vehicles. The pneumatic system consists of an air tank and a compressor–expander that is coupled to the rest of the drivetrain via an infinitely variable transmission. Rather than incorporating more expensive technologies such as variable valve timing or a variable compression ratio compressor, a fixed valve system consisting of a rotary valve and passive check valves is optimized to operate efficiently over a range of tank pressures. The feasibility of this approach is established by thermodynamic modeling and the construction of a proof-of-concept prototype, which is also used to fine tune model parameters. While the proof-of-concept system shows a round trip efficiency of just under 10%, modeling shows that a round trip efficiency of 26% is possible with a revised design. If waste heat from the engine is used to maintain an elevated tank temperature, efficiencies of nearly 50% may be possible, indicating that the concept could be effective for practical hybridization of passenger vehicles

  11. A Feasibility Study on Operating Large Scale Compressed Air Energy Storage in Porous Formations

    Science.gov (United States)

    Wang, B.; Pfeiffer, W. T.; Li, D.; Bauer, S.

    2015-12-01

    Compressed air energy storage (CAES) in porous formations has been considered as one promising option of large scale energy storage for decades. This study, hereby, aims at analyzing the feasibility of operating large scale CAES in porous formations and evaluating the performance of underground porous gas reservoirs. To address these issues quantitatively, a hypothetic CAES scenario with a typical anticline structure in northern Germany was numerically simulated. Because of the rapid growth in photovoltaics, the period of extraction in a daily cycle was set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. The gas turbine scenario was defined referring to the specifications of the Huntorf CAES power plant. The numerical simulations involved two stages, i.e. initial fill and cyclic operation, and both were carried out using the Eclipse E300 simulator (Schlumberger). Pressure loss in the gas wells was post analyzed using an analytical solution. The exergy concept was applied to evaluate the potential energy amount stored in the specific porous formation. The simulation results show that porous formations prove to be a feasible solution of large scale CAES. The initial fill with shut-in periods determines the spatial distribution of the gas phase and helps to achieve higher gas saturation around the wells, and thus higher deliverability. The performance evaluation shows that the overall exergy flow of stored compressed air is also determined by the permeability, which directly affects the deliverability of the gas reservoir and thus the number of wells required.

  12. Feasibility study of porous media compressed air energy storage in South Carolina, United States of America

    Science.gov (United States)

    Jarvis, Alexandra-Selene

    Renewable Energy Systems (RES) such as solar and wind, are expected to play a progressively significant role in electricity production as the world begins to move away from an almost total reliance on nonrenewable sources of power. In the US there is increasing investment in RES as the Department of Energy (DOE) expands its wind power network to encompass the use of offshore wind resources in places such as the South Carolina (SC) Atlantic Coastal Plain. Because of their unstable nature, RES cannot be used as reliable grid-scale power sources unless power is somehow stored during excess production and recovered at times of insufficiency. Only two technologies have been cited as capable of storing renewable energy at this scale: Pumped Hydro Storage and Compressed Air Energy Storage (CAES). Both CAES power plants in existence today use solution-mined caverns as their storage spaces. This project focuses on exploring the feasibility of employing the CAES method to store excess wind energy in sand aquifers. The numerical multiphase flow code, TOUGH2, was used to build models that approximate subsurface sand formations similar to those found in SC. Although the aquifers of SC have very low dips, less than 10, the aquifers in this study were modeled as flat, or having dips of 00. Cycle efficiency is defined here as the amount of energy recovered compared to the amount of energy injected. Both 2D and 3D simulations have shown that the greatest control on cycle efficiency is the volume of air that can be recovered from the aquifer after injection. Results from 2D simulations showed that using a dual daily peak load schedule instead of a single daily peak load schedule increased cycle efficiency as do the following parameters: increased anisotropy, screening the well in the upper portions of the aquifer, reduced aquifer thickness, and an initial water displacement by the continuous injection of air for at least 60 days. Aquifer permeability of 1x10-12 m2 produced a cycle

  13. Om distributionen af hvidhed

    DEFF Research Database (Denmark)

    Frello, Birgitta

    2007-01-01

    Med udgangspunkt i John Fords Western, Forfølgeren fra 1956, præsenteres en analyse af repræsentationer af race og overskridelse af raceskel, særligt i relation til konstitueringen af subjektpositioner, hvorfra spørgsmål om hvidhed og ikke-hvidhed kan afgøres....

  14. Undervisning af tosprogede elever

    DEFF Research Database (Denmark)

    Horst, Christian

    2003-01-01

    Artiklen fremdrager hovedresultaterne fra Virginia P. Collier's og Wayne P. Thomas's længdeundersøgelser af tosprogede elever i USA, som formentlig er de mest omfattende undersøgelser af undervisningen af tosprogede elever overhovedet. Resultaterne diskuteres i relation til udviklingen af en...

  15. COP Prediction of an ejector refrigeration cycle combined with a vapour compression cycle for automotive air conditioning

    OpenAIRE

    Nat Suvarnakuta; Nutthanun Keerlatiyadatanapat; Thanarath Sriveerakul

    2014-01-01

    This paper presents the COP prediction of an ejector refrigeration cycle combined with a vapour compression cycle for automotive air conditioning. Using computational fluid dynamics (CFD) technique, the performance of an ejector was analyzed in term of the entrainment ratio (Rm) and critical back pressure (CBP). The results from this study were compared with a previous study of combined ejector refrigeration system for automotive air conditioning application [1] which the entrainment ratio (R...

  16. A CASE OF TENSION PNEUMOPERITONEUM DUE TO COLONIC BAROTRAUMA WITH COMPRESSED AIR

    Directory of Open Access Journals (Sweden)

    Shashidhara

    2014-09-01

    Full Text Available A 23 year old male working in a biscuit factory was brought to emergency department by the coworkers at 4PM with pain abdomen and distension and bleeding per rectum. On further questioning the patient confessed that his co-workers had held him firmly and directed the stream of air from a compressed-air pipeline towards his anal region in the morning. On examination, he was alerting conscious and oriented and tachypneic. The respiratory rate was 30/min, SPO2- 80%, Pulse was 120/min and B.P. 120/80 mm Hg. On palpation, Abdomen was grossly distended (Fig. 1, tense with generalized tenderness and rigidity of abdominal wall. The percussion note was tympanitic and liver dullness obliterated. No free fluid was detected. Bowel sounds were absent. Examination of the perineum did not show any external injury. Rectal examination showed faeces mixed with fresh blood but did not reveal any laceration or perforation in the anal canal or rectum. Straight X-ray abdomen in erect position showed extensive pneumoperitoneum

  17. Performance Analysis of a Coal-Fired External Combustion Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-11-01

    Full Text Available Compressed air energy storage (CAES is one of the large-scale energy storage technologies utilized to provide effective power peak load shaving. In this paper, a coal-fired external combustion CAES, which only uses coal as fuel, is proposed. Unlike the traditional CAES, the combustion chamber is substituted with an external combustion heater in which high-pressure air is heated before entering turbines to expand in the proposed system. A thermodynamic analysis of the proposed CAES is conducted on the basis of the process simulation. The overall efficiency and the efficiency of electricity storage are 48.37% and 81.50%, respectively. Furthermore, the exergy analysis is then derived and forecasted, and the exergy efficiency of the proposed system is 47.22%. The results show that the proposed CAES has more performance advantages than Huntorf CAES (the first CAES plant in the world. Techno-economic analysis of the coal-fired CAES shows that the cost of electricity (COE is $106.33/MWh, which is relatively high in the rapidly developing power market. However, CAES will be more likely to be competitive if the power grid is improved and suitable geographical conditions for storage caverns are satisfied. This research provides a new approach for developing CAES in China.

  18. Theoretical evaluation on the impact of heat exchanger in Advanced Adiabatic Compressed Air Energy Storage system

    International Nuclear Information System (INIS)

    Highlights: • A multi-stage AA-CAES system model is established based on thermodynamic theory. • Four Cases about pressure loss and effectiveness of heat exchanger are investigated. • The impact of pressure loss on conversion of heat energy in TES is more sensitive. • The impact of heat exchanger effectiveness in charge process on system is stronger. • Pressure loss in heat exchanger affects the change trends of system efficiency. - Abstract: Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) is a large-scale energy storage system based on gas turbine technology and thermal energy storage (TES). Electrical energy can be converted into internal energy of air and heat energy in TES during the charge process, while reverse energy conversion proceeds during discharge process. The performance of AA-CAES system requires further improvement in order to increase efficiency. In this paper, a multi-stage AA-CAES system model is established, and the influence of effectiveness and pressure loss in heat exchanger on energy conversion and utilization efficiency of AA-CAES system is analyzed theoretically based on the theory of thermodynamics. Four Cases about effectiveness and pressure loss of heat exchanger are investigated and compared with each other. It is found that effectiveness and pressure loss of heat exchanger are directly related to energy conversion and utilization in AA-CAES system. System efficiency changes with the variation of heat exchanger effectiveness and the impact of pressure loss on conversion of heat energy in TES is more sensitive than that of internal energy of air. Pressure loss can cause the complexity of system efficiency change. With appropriate selection of the values of heat exchanger effectiveness for both charge and discharge processes, an AA-CAES system with a higher efficiency could be expected

  19. An Analytical Solution for Mechanical Responses Induced by Temperature and Air Pressure in a Lined Rock Cavern for Underground Compressed Air Energy Storage

    Science.gov (United States)

    Zhou, Shu-Wei; Xia, Cai-Chu; Du, Shi-Gui; Zhang, Ping-Yang; Zhou, Yu

    2015-03-01

    Mechanical responses induced by temperature and air pressure significantly affect the stability and durability of underground compressed air energy storage (CAES) in a lined rock cavern. An analytical solution for evaluating such responses is, thus, proposed in this paper. The lined cavern of interest consists of three layers, namely, a sealing layer, a concrete lining and the host rock. Governing equations for cavern temperature and air pressure, which involve heat transfer between the air and surrounding layers, are established first. Then, Laplace transform and superposition principle are applied to obtain the temperature around the lined cavern and the air pressure during the operational period. Afterwards, a thermo-elastic axisymmetrical model is used to analytically determine the stress and displacement variations induced by temperature and air pressure. The developments of temperature, displacement and stress during a typical operational cycle are discussed on the basis of the proposed approach. The approach is subsequently verified with a coupled compressed air and thermo-mechanical numerical simulation and by a previous study on temperature. Finally, the influence of temperature on total stress and displacement and the impact of the heat transfer coefficient are discussed. This paper shows that the temperature sharply fluctuates only on the sealing layer and the concrete lining. The resulting tensile hoop stresses on the sealing layer and concrete lining are considerably large in comparison with the initial air pressure. Moreover, temperature has a non-negligible effect on the lined cavern for underground compressed air storage. Meanwhile, temperature has a greater effect on hoop and longitudinal stress than on radial stress and displacement. In addition, the heat transfer coefficient affects the cavern stress to a higher degree than the displacement.

  20. Geochemical effects of compressed air, methane, or hydrogen intrusion into shallow aquifers

    Science.gov (United States)

    Berta, Marton; Dethlefsen, Frank; Ebert, Markus; Dahmke, Andreas

    2016-04-01

    The fluctuating energy yield of renewable sources, most importantly wind and solar, implies the emerging necessity of energy storage. Already operating possibilities for geological energy storage include storage of compressed air (CAES), methane, and hydrogen. For the safe and sustainable implementation of subsurface energy storage, site specific risk assessment studies and elaborated monitoring strategies are needed, based on proper process understanding. In case of gas storage, this process understanding must include gas-specific reactions to be expected in shallow aquifers following a leakage of compressed air, methane, or hydrogen, and therefore potentially changing the composition of the groundwater, which is protected by law. As the geochemical reactions potentially following gas leakages were not known in a sufficient extent, experiments representing relevant hydrogeological conditions were carried out. The experimental approach included batch and column experiments using mainly sediment from a shallow Pleistocene aquifer percolated by the groundwater from the same aquifer. This water was saturated with the respective gas to simulate a leakage environment in a shallow aquifer. Leakage of compressed air resulted in pyrite oxidation (rates up to 4 μM/h). In our experimental conditions with oxygen partial pressures between 0 and 11 bars pyrite oxidation caused minor (up to 0.5 mM) increase in sulfate concentration and minor (up to 0.5) decrease in pH. The transfer function on reaction kinetics developed using PHREEQC based on the experimental reaction rates for upscaling the results includes a passivation inhibiting more than 90% of the pyrite reactivity. Methane oxidation coupled to reduction of nitrate, and especially sulfate is known from various groundwater and marine environments. However, fugitive methane does not cause detectable changes in groundwater within one year in our experiments. This acknowledges earlier field studies describing no methane

  1. Analysis the Energy Process of the Air Being Compressed by the Method of Exergy%分析法解析空气压缩能量过程

    Institute of Scientific and Technical Information of China (English)

    孙晓明; 林子良

    2014-01-01

    With the second law of thermodynamics,the energy transformation in the process of air being compressed and com-pressed air working were analyzed.Tell the air being compressed is that compression-work replacement for the compressed air in the exergy.To improve the quality of the air energy.%用热力学第二定律,分析了空气被压缩和压缩空气做功的能量转换;说明了空气压缩机工作是压缩功置换为压缩空气能量(有效能)的过程,改变了空气能量的“质”。

  2. Lyden af musik - er lyden af idealisme

    DEFF Research Database (Denmark)

    Eigtved, Michael

    2015-01-01

    Programartiklen til Det Ny Teaters opsætning af Rodgers & Hammersteins The Sound of Music, undersøger musicalgenrens - og især de konkrete ophavsmænds- affinitet til fremstillingen af såvel idealistiske som ideologiske universer.......Programartiklen til Det Ny Teaters opsætning af Rodgers & Hammersteins The Sound of Music, undersøger musicalgenrens - og især de konkrete ophavsmænds- affinitet til fremstillingen af såvel idealistiske som ideologiske universer....

  3. Simulering af fotoinitieret nedbrydning af maling

    DEFF Research Database (Denmark)

    Kiil, Søren

    2013-01-01

    Beskyttende malingslag udsat for sollys, ilt og vand forvitrer gennem en række komplicerede fysiske og kemiske processer. Glasovergangstemperaturen af malingen og tilstedeværelsen af små mængder lysstabilisatorer har stor indflydelse på nedbrydningshastigheden.......Beskyttende malingslag udsat for sollys, ilt og vand forvitrer gennem en række komplicerede fysiske og kemiske processer. Glasovergangstemperaturen af malingen og tilstedeværelsen af små mængder lysstabilisatorer har stor indflydelse på nedbrydningshastigheden....

  4. Economics of compressed air energy storage to integrate wind power: A case study in ERCOT

    International Nuclear Information System (INIS)

    Compressed air energy storage (CAES) could be paired with a wind farm to provide firm, dispatchable baseload power, or serve as a peaking plant and capture upswings in electricity prices. We present a firm-level engineering-economic analysis of a wind/CAES system with a wind farm in central Texas, load in either Dallas or Houston, and a CAES plant whose location is profit-optimized. With 2008 hourly prices and load in Houston, the economically optimal CAES expander capacity is unrealistically large - 24 GW - and dispatches for only a few hours per week when prices are highest; a price cap and capacity payment likewise results in a large (17 GW) profit-maximizing CAES expander. Under all other scenarios considered the CAES plant is unprofitable. Using 2008 data, a baseload wind/CAES system is less profitable than a natural gas combined cycle (NGCC) plant at carbon prices less than $56/tCO2 ($15/MMBTU gas) to $230/tCO2 ($5/MMBTU gas). Entering regulation markets raises profit only slightly. Social benefits of CAES paired with wind include avoided construction of new generation capacity, improved air quality during peak times, and increased economic surplus, but may not outweigh the private cost of the CAES system nor justify a subsidy. - Research highlights: → Sizes of CAES and transmission paired with a Texas wind farm are optimized for profit. → A profit-maximizing wind farm owner would not invest in a dedicated CAES system. → The social benefit of a wind/CAES system is unlikely to outweigh private cost. → CAES cannot cost-effectively smooth wind power with plausible imminent carbon prices.

  5. Conceptual design and engineering studies of adiabatic compressed air energy storage (CAES) with thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hobson, M. J.

    1981-11-01

    The objective of this study was to perform a conceptual engineering design and evaluation study and to develop a design for an adiabatic CAES system using water-compensated hard rock caverns for compressed air storage. The conceptual plant design was to feature underground containment for thermal energy storage and water-compensated hard rock caverns for high pressure air storage. Other design constraints included the selection of turbomachinery designs that would require little development and would therefore be available for near-term plant construction and demonstration. The design was to be based upon the DOE/EPRI/PEPCO-funded 231 MW/unit conventional CAES plant design prepared for a site in Maryland. This report summarizes the project, its findings, and the recommendations of the study team; presents the development and optimization of the plant heat cycle and the selection and thermal design of the thermal energy storage system; discusses the selection of turbomachinery and estimated plant performance and operational capability; describes the control system concept; and presents the conceptual design of the adiabatic CAES plant, the cost estimates and economic evaluation, and an assessment of technical and economic feasibility. Particular areas in the plant design requiring further development or investigation are discussed. It is concluded that the adiabatic concept appears to be the most attractive candidate for utility application in the near future. It is operationally viable, economically attractive compared with competing concerns, and will require relatively little development before the construction of a plant can be undertaken. It is estimated that a utility could start the design of a demonstration plant in 2 to 3 years if research regarding TES system design is undertaken in a timely manner. (LCL)

  6. Guidelines for the pressure and efficient sizing of pressure vessels for compressed air energy storage

    International Nuclear Information System (INIS)

    Highlights: ► In small-scale CAES there are no robust guidelines in choosing an operational pressure for the vessels. ► Through the stress analysis of the vessel, an optimum pressure at minimum cost can be determined. ► One contribution is in determining the optimum pressure is small-scale CAES. ► Another contribution is in determining the shape size, and number of vessels in small-scale CAES designs. - Abstract: The paper reports guidelines for the efficient design and sizing of Small-Scale Compressed Air Energy Storage (SS-CAES) pressure vessels, including guidelines for pressures that should be used in the SS-CAES system to minimize the cost of the pressure vessel. Under a specified energy storage capacity and specified maximum and minimum operating pressures in CAES, the volume of the vessel(s) can be evaluated. The present study provides guidelines for choosing appropriate shape and size for the vessels that minimize material and manufacturing cost for cylindrical vessels. The two main contributions of the paper are that it provides a methodology to determine: (a) an optimum pressure; (b) the shape, size, and number of vessel to be used in a particular application. Results suggest that pressure vessels with a length to diameter ratio of roughly three are the most economical, and that a system should be designed for a pressure of roughly three times the minimum pressure of the expansion device.

  7. Optimization of specific rating for wind turbine arrays coupled to compressed air energy storage

    International Nuclear Information System (INIS)

    Highlights: ► The economics of a wind farm coupled to an energy storage system are modeled. ► The combined system is designed to deliver baseload power at least cost. ► The model jointly optimizes the wind turbine array power curve and the storage system configuration. ► This yields a combined baseload system very different from wind and storage systems optimized for standalone operation. ► The result is reduced cost, emissions and storage requirements. -- Abstract: A methodology is presented for jointly optimizing the wind turbine specific rating and the storage configuration for a large-scale wind farm coupled to compressed air energy storage (CAES). By allowing the wind-storage system to be optimized in an integrated, variable rating framework the levelized cost of electricity (LCOE) can be reduced substantially. These changes also enhance the capacity factor of the wind farm, reduce the storage capacity requirements of the baseload plant and reduce the greenhouse gas emission rate of the combined system relative to a separately optimized wind farm coupled to CAES. The results of this analysis could have important implications for the competitiveness of large-scale remote wind and the applicability of energy storage as a baseload wind strategy in a carbon constrained world.

  8. Optimal Acoustic Attenuation of Weakly Compressible Media Permeated with Air Bubbles

    Institute of Scientific and Technical Information of China (English)

    LIANG Bin; CHENG Jian-Chun

    2007-01-01

    Based on fuzzy logic (FL) and genetic algorithm (GA), we present an optimization method to obtain the optimal acoustic attenuation of a longitudinal acoustic wave propagating in a weakly compressible medium permeated with air bubbles. In the optimization, the parameters of the size distribution of bubbles in the medium are optimized for providing uniformly high acoustic attenuation in the frequency band of interest. Compared with other traditional optimization methods, the unique advantage of the present method is that it can locate the global optimum quickly and effectively in need of knowing the mathematical model precisely. As illustrated by a numerical simulation, the method is effective and essential in enhancing the acoustic attenuation of such a medium in an optimal manner. The bubbly medium with optimized structural parameters can effectively attenuate longitudinal waves at intermediate frequencies with an acoustic attenuation approximating a constant value of 10(dB/cm). Such bubbly media with optimal acoustic attenuations may be applied to design acoustic absorbent by controlling broader attenuation band and higher efficiency.

  9. Investigation and study on compressed air storage power generation system, part 2

    Science.gov (United States)

    1989-03-01

    Compressed air storage power generation system (CAES) was studied. As a system for response to peak loads, both output and efficiency were better than those of the previous year due to the study on the temperature of the turbine's inlet. As a system for response to peak and middle loads, steam power generation, which makes use of exhaust heat from the aftercooler and the low pressure turbine's outlet, was integrated into the system, and its heat efficiency was better than that of the usual thermal power generation. However, it is inferior to the latest LNG combined cycle power generation and it does not appeal much as a middle load power source. Deformation strength characteristics of the underground cavity rocks were clarified, and a multi-structure lining method was suggested. Its location area is restricted by the layer distribution. Construction cost per kW is 220,000 yen, and the power generation prime cost is a little higher than that of pumped storage power generation. As a pumped storage power station has difficulty in finding suitable location and is higher in costs, CAES can be put into existence as a system for response to peak loads in view of economy in the future.

  10. Modeling and integration of a heat storage tank in a compressed air electricity storage process

    International Nuclear Information System (INIS)

    Highlights: • Large-scale heat storage tank behavior is explored with a two dimensional model. • Thermal storage tank efficiencies are estimated thanks to dimensionless numbers. • Abacuses of the tank efficiency are provided. • The link between tank efficiency and A-CAES global efficiency is generated. - Abstract: In an adiabatic compressed air energy storage process (A-CAES), heat storage tank operation is a key factor that determines the overall energy performance of the process. To highlight energy issues linked to a correct tank design in the specific case of an A-CAES system, a two-dimensional thermal numerical model was developed. Thermal efficiencies of the tank are presented with abacus defined from the four dimensionless numbers defining the thermal behavior of the reservoir. Cycling effects are explored with a realistic case study corresponding to an A-CAES system design to deliver an electrical power of 250 MWel for 4 h, the daily peak demand. Extended beyond the thermal reservoir, A-CAES thermodynamic analysis combined with the dynamic simulation makes it possible to generate a direct quantitative link between reservoir sizing and A-CAES global efficiency

  11. Optimering af model for spredning af luftforurening

    DEFF Research Database (Denmark)

    Pedersen, Jens Christian

    2008-01-01

    De nuværende luftforureningsmodeller har problemer med at bevare massen af diverse kemiske stoffer og med at der ind i mellem optræder negative værdier. Derfor arbejder specialestuderende Ayoe Buus Hansen på om at forbedre den model DMU bruger til at beskrive transport og spredning af...

  12. Livscyklusvurdering af behandling af deponeret shredderaffald

    DEFF Research Database (Denmark)

    Møller, Jacob; Damgaard, Anders; Brogaard, Line Kai-Sørensen;

    Denne rapport indeholder en livscyklusbaseret miljøvurdering (LCA) af behandling af deponeret shredderaffald. Livscyklusvurderingen blev udført for Miljøstyrelsen af DTU Miljø i perioden 2013-2014 som en del af en ydelsesaftale mellem Miljøstyrelsen og DTU om forskningsbaseret myndighedsbetjening...... in-den for affaldsområdet. Rapporten indgår i en større undersøgelse vedrørende bedre ressourceud-nyttelse af affald, hvori såvel den miljømæssige som den samfundsøkonomiske konsekvens for forskellige scenarier vedr. affaldshåndtering af shredderaffald, imprægneret træ, træ til genanven-delse samt...... fjernvarmerør undersøges. Livscyklusvurderingen blev udført vha. LCA-modellen EA-SETECH, som er udviklet af DTU Miljø til miljøvurdering af affaldssystemer. Livscyklusvurderingen blev udført i overensstemmelse med principperne for LCA, som beskrevet i DS/EN ISO-standard 14044. Afrapporteringen følger ISO...

  13. Thermodynamic analysis of a hybrid thermal-compressed air energy storage system for the integration of wind power

    International Nuclear Information System (INIS)

    In China, a large amount of wind power is abandoned due to the difficulty of integrating fluctuating wind power into electricity grid systems. Advanced adiabatic compressed air energy storage (AA-CAES) is regarded as a promising emission-free technology to facilitate the wind power integration, but its high capital cost has hindered its wide commercialization. In the present work, a novel hybrid system was proposed on the basis of AA-CAES. It can reduce abandoned wind power and improve the financial return per capital cost of the system by increasing power output. In the new system, which is called hybrid thermal-compressed air energy storage (HTCAES), thermal energy storage (TES) units absorb the heat released from air compression and also the thermal energy converted from reluctant wind power using electrical heaters. Theoretical thermodynamic analyses show that the HTCAES system can absorb much more wind power than an AA-CAES system with the same scale of compressors, turbines, and TES units do. And recovery efficiency of this additional wind power is about 41–47%, depending on the final storage temperature of the TES. The power output ratio of the HTCAES system to the AA-CAES system increases with the maximum TES storage temperature and decreases with the operating pressure. - Highlights: •A novel concept of adiabatic compressed air energy storage is proposed. •Heat TES using electricity heaters after TES absorbs heat from air. •Power storage capacity of the new system can be greatly increased. •Recovery efficiency of the wind power used for electric heating is about 41–47%. •Power output increase is about 19–125% depending on the TES storage temperature

  14. Styring af blodfortyndende medicin

    DEFF Research Database (Denmark)

    Kallestrup, Lisbeth

    2010-01-01

    Artiklen beskriver sygeplejerskers dosering af AK- behandling. Hovedbudskabet er, at kvaliteten af doseringen til patienterne bevares eller måske forbedres, såfremt ansvaret for doseringen overdrages fra læger til sygeplejersker. Udgivelsesdato: 23092010...

  15. Vi lever af myter

    DEFF Research Database (Denmark)

    Bilde, Per

    2005-01-01

    En kritisk gennemgang af en kronik om regeringens forsknings- og universitetspolitik af Helge Sander, Minister for Videnskab, Teknologi og Udvikling: "Myter om universiteter står for fald" (Morgenavisen Jyllands-Posten 11/11 2005)...

  16. Evaluering af undervisning

    DEFF Research Database (Denmark)

    Jensen, Torben K.

    2007-01-01

    evaluering, læring og spørgeskemaer - en række generelle principper og hensyn ved evaluering af undervisning I notatets anden del fremsættes et konkret forslag til en procedure for evaluering af undervisning......evaluering, læring og spørgeskemaer - en række generelle principper og hensyn ved evaluering af undervisning I notatets anden del fremsættes et konkret forslag til en procedure for evaluering af undervisning...

  17. Regulering af lysesiv

    OpenAIRE

    Buttenschøn, R.M.; Nielsen, L.

    2004-01-01

    Lysesiv optrader ofte som problemart i forbindelse med retablering af naturenge og ved etablering af "våde enge". Marginalisering og ekstensivering af engdriften i Danmark og andre europæiske lande har betydet, at lysesiv har bredt sig og mange steder betragtes som et stort problem. Målrettet græsning er en af mulighederne for bekæmpelse.

  18. En verden af medier

    DEFF Research Database (Denmark)

    Tække, Jesper

    2009-01-01

    Bogen: 'En verden af medier – Medialiseringen af politik, sprog, religion og leg' anmeldes. Anmeldelsen kan læses på: http://ojs.statsbiblioteket.dk/index.php/mediekultur/article/view/1370/1499 Udgivelsesdato: 2009......Bogen: 'En verden af medier – Medialiseringen af politik, sprog, religion og leg' anmeldes. Anmeldelsen kan læses på: http://ojs.statsbiblioteket.dk/index.php/mediekultur/article/view/1370/1499 Udgivelsesdato: 2009...

  19. Kombinationseffekter af pesticider

    DEFF Research Database (Denmark)

    Kudsk, Per; Andersen, Helle Raun; Cedergreen, Nina;

    Resumé: Effekten af 101 tokomponentblandinger og 20 trekomponentblandinger bestående af 22 forskellige pesticider blev undersøgt i 7 forskellige testsystemer. Effekterne af blandingerne blev sammenholdt med pesticidernes virkningsmekanismer/virkemåder med henblik på at undersøge, om det med...

  20. Digital formidling af kulturarv

    DEFF Research Database (Denmark)

    En af tidens store kulturelle dagsordner drejer sig om digital tilgængeliggørelse af kulturarv. Fortidens spor dukker op i nye former på nettet - næsten alle kulturinstitutioner arbejder med, og befolkningen har fået helt nye muligheder for at se med og deltage. Digital formidling af kulturarv...

  1. Udvidelse af Drastrup kildeplads

    DEFF Research Database (Denmark)

    Jensen, Jacob Birk; Grønvald, Per; Thomsen, Janni; Bliksted, Torsten

    håndteret ved at opstille flere modeller af områdets hydrogeologi, dels ved en såkaldt prædiktionsanalyse, hvor usikkerhedsbidraget fra modellens parametre belyses. Den samlede risikovurdering viste, at den ønskede udvidelse af kildepladsen indebar en risiko for sænkning af grundvandsstanden til et kritisk...

  2. Renovering af enfamiliehuset

    DEFF Research Database (Denmark)

    Gram-Hanssen, Kirsten; Bech-Danielsen, Claus

    Meddelelsen beskriver et pilotprojekt, der undersøger hvilke arkitektoniske og økologiske overvejelser ejere af enfamiliehuse gør sig, når de renoverer deres huse. Undersøgelsen tager udgangspunkt i to kvarterer dels fra begyndelsen af 1950'erne, dels fra slutningen af 1960'erne. Gennem spørgeske...

  3. Optimering af kollektiv transport

    DEFF Research Database (Denmark)

    Larsen, Allan; Petersen, Hanne Løhmann

    2013-01-01

    Det kollektive transportsystem er af vital betydning for specielt de større byer. Uden det kollektive udbud af trafik vil vejene sande til, og mobiliteten (fremkommeligheden) mindskes væsentligt. De fleste mennesker, der gør brug af det kollektive transportsystem, stiller sig spørgsmål som: Kan d...

  4. Livscyklusvurdering af basiskemikalier

    DEFF Research Database (Denmark)

    Olsen, Stig Irving

    1998-01-01

    Dette resumé af metoder og væsentlige erfaringer fra erhvervsforskerprojektet Livscyklusvurdering af basiskemikalier er skrevet i erkendelse af, at hovedrapporten er for omfattende til en hurtig introduktion i problemstillingerne. Formålet med denne rapport er derfor at give et kort overblik over...

  5. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

    2005-12-01

    This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

  6. Siting-selection study for the Soyland Power Cooperative, Inc. , compressed-air energy-storage system (CAES)

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    A method used for siting a compressed air energy storage (CAES) system using geotechnical and environmental criteria is explained using the siting of a proposed 220 MW water-compensated CAES plant in Illinois as an example. Information is included on the identification and comparative ranking of 28 geotechnically and environmental sites in Illinois, the examination of fatal flaws, e.g., mitigation, intensive studies, costly studies, permit denials, at 7 sites; and the selection of 3 sites for further geological surveying. (LCL)

  7. Site specific comparison of H2, CH4 and compressed air energy storage in porous formations

    Science.gov (United States)

    Tilmann Pfeiffer, Wolf; Wang, Bo; Bauer, Sebastian

    2016-04-01

    The supply of energy from renewable sources like wind or solar power is subject to fluctuations determined by the climatic and weather conditions, and shortage periods can be expected on the order of days to weeks. Energy storage is thus required if renewable energy dominates the total energy production and has to compensate the shortages. Porous formations in the subsurface could provide large storage capacities for various energy carriers, such as hydrogen (H2), synthetic methane (CH4) or compressed air (CAES). All three energy storage options have similar requirements regarding the storage site characteristics and consequently compete for suitable subsurface structures. The aim of this work is to compare the individual storage methods for an individual storage site regarding the storage capacity as well as the achievable delivery rates. This objective is pursued using numerical simulation of the individual storage operations. In a first step, a synthetic anticline with a radius of 4 km, a drop of 900 m and a formation thickness of 20 m is used to compare the individual storage methods. The storage operations are carried out using -depending on the energy carrier- 5 to 13 wells placed in the top of the structure. A homogeneous parameter distribution is assumed with permeability, porosity and residual water saturation being 500 mD, 0.35 and 0.2, respectively. N2 is used as a cushion gas in the H2 storage simulations. In case of compressed air energy storage, a high discharge rate of 400 kg/s equating to 28.8 mio. m³/d at surface conditions is required to produce 320 MW of power. Using 13 wells the storage is capable of supplying the specified gas flow rate for a period of 31 hours. Two cases using 5 and 9 wells were simulated for both the H2 and the CH4 storage operation. The target withdrawal rates of 1 mio. sm³/d are maintained for the whole extraction period of one week in all simulations. However, the power output differs with the 5 well scenario producing

  8. The role of compressed air energy storage (CAES) in future sustainable energy systems

    International Nuclear Information System (INIS)

    Future sustainable energy systems call for the introduction of integrated storage technologies. One of these technologies is compressed air energy storage (CAES). In Denmark at present, wind power meets 20% and combined heat and power production (CHP) meets 50% of the electricity demand. Based on these figures, the paper assesses the value of integrating CAES into future sustainable energy systems with even higher shares of fluctuating renewable energy sources. The evaluation is made on the basis of detailed energy system analyses in which the supply of complete national energy systems is calculated hour by hour in relation to the demands during a year. The Danish case is evaluated in a system-economic perspective by comparing the economic benefits achieved by improving the integration of wind power to the costs of the CAES technology. The result is compared to various other storage options. Furthermore, a business-economic evaluation is done by calculating the potential income of the CAES technology from both spot markets and regulating power markets. The evaluation includes both historical hour by hour prices during a 7-year period on the Nordic Nord Pool market as well as expected future price variations. The conclusion is that even in energy systems with very high shares of wind power and CHP, neither the historical nor the expected future price variations on the spot market alone can justify the investment in CAES systems. Other storage technology options are significantly more feasible. CAES may operate both on the spot market and the regulating power market, which indicates potential feasibility. However, such strategy is highly risky because of the small extent of the regulating power market and if CAES is to become feasible it will depend on incomes from auxiliary services.

  9. The role of compressed air energy storage (CAES) in future sustainable energy systems

    International Nuclear Information System (INIS)

    Future sustainable energy systems call for the introduction of integrated storage technologies. One of these technologies is compressed air energy storage (CAES). In Denmark at present, wind power meets 20% and combined heat and power production (CHP) meets 50% of the electricity demand. Based on these figures, the paper assesses the value of integrating CAES into future sustainable energy systems with even higher shares of fluctuating renewable energy sources. The evaluation is made on the basis of detailed energy system analyses in which the supply of complete national energy systems is calculated hour by hour in relation to the demands during a year. The Danish case is evaluated in a system-economic perspective by comparing the economic benefits achieved by improving the integration of wind power to the costs of the CAES technology. The result is compared to various other storage options. Furthermore, a business-economic evaluation is done by calculating the potential income of the CAES technology from both spot markets and regulating power markets. The evaluation includes both historical hour by hour prices during a 7-year period on the Nordic Nord Pool market as well as expected future price variations. The conclusion is that even in energy systems with very high shares of wind power and CHP, neither the historical nor the expected future price variations on the spot market alone can justify the investment in CAES systems. Other storage technology options are significantly more feasible. CAES may operate both on the spot market and the regulating power market, which indicates potential feasibility. However, such strategy is highly risky because of the small extent of the regulating power market and if CAES is to become feasible it will depend on incomes from auxiliary services. (author)

  10. Tension-Compression Fatigue of a Nextel™720/alumina Composite at 1200 °C in Air and in Steam

    Science.gov (United States)

    Lanser, R. L.; Ruggles-Wrenn, M. B.

    2016-02-01

    Tension-compression fatigue behavior of an oxide-oxide ceramic-matrix composite was investigated at 1200 °C in air and in steam. The composite is comprised of an alumina matrix reinforced with Nextel™720 alumina-mullite fibers woven in an eight harness satin weave (8HSW). The composite has no interface between the fiber and matrix, and relies on the porous matrix for flaw tolerance. Tension-compression fatigue behavior was studied for cyclical stresses ranging from 60 to 120 MPa at a frequency of 1.0 Hz. The R ratio (minimum stress to maximum stress) was -1.0. Fatigue run-out was defined as 105 cycles and was achieved at 80 MPa in air and at 70 MPa in steam. Steam reduced cyclic lives by an order of magnitude. Specimens that achieved fatigue run-out were subjected to tensile tests to failure to characterize the retained tensile properties. Specimens subjected to prior cyclic loading in air retained 100 % of their tensile strength. The steam environment severely degraded tensile properties. Tension-compression cyclic loading was considerably more damaging than tension-tension cyclic loading. Composite microstructure, as well as damage and failure mechanisms were investigated.

  11. Tension-Compression Fatigue of a Nextel™720/alumina Composite at 1200 °C in Air and in Steam

    Science.gov (United States)

    Lanser, R. L.; Ruggles-Wrenn, M. B.

    2016-08-01

    Tension-compression fatigue behavior of an oxide-oxide ceramic-matrix composite was investigated at 1200 °C in air and in steam. The composite is comprised of an alumina matrix reinforced with Nextel™720 alumina-mullite fibers woven in an eight harness satin weave (8HSW). The composite has no interface between the fiber and matrix, and relies on the porous matrix for flaw tolerance. Tension-compression fatigue behavior was studied for cyclical stresses ranging from 60 to 120 MPa at a frequency of 1.0 Hz. The R ratio (minimum stress to maximum stress) was -1.0. Fatigue run-out was defined as 105 cycles and was achieved at 80 MPa in air and at 70 MPa in steam. Steam reduced cyclic lives by an order of magnitude. Specimens that achieved fatigue run-out were subjected to tensile tests to failure to characterize the retained tensile properties. Specimens subjected to prior cyclic loading in air retained 100 % of their tensile strength. The steam environment severely degraded tensile properties. Tension-compression cyclic loading was considerably more damaging than tension-tension cyclic loading. Composite microstructure, as well as damage and failure mechanisms were investigated.

  12. Efterforskning af drab i Kosovo

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2000-01-01

    Gennemgang af baggrunden for den retsmedicinske mission til Kosovo i 1999, og af 50 obduktioner udført af forfatteren i denne forbindelse.......Gennemgang af baggrunden for den retsmedicinske mission til Kosovo i 1999, og af 50 obduktioner udført af forfatteren i denne forbindelse....

  13. Gensplejsning af byg uden brug af selektionsgener

    DEFF Research Database (Denmark)

    Holme, Inger B; Brinch-Pedersen, Henrik; Lange, Mette;

    2008-01-01

    Genetisk modificerede planter indeholder som regel gener, som gør planten modstandsdygtig overfor enten et ukrudtsmiddel eller et antibiotikum. Disse gener, som benyttes i forbindelse med selektion af genetisk modificerede celler, er generelt uønskede i planter, som skal dyrkes kommercielt. En ny...... metode gør det muligt at fremstille genetisk modificerede bygplanter uden brug af selektionsgener. Udgivelsesdato: Juni 2008...

  14. Potential energy savings and environmental impacts of energy efficiency standards for vapor compression central air conditioning units in China

    Energy Technology Data Exchange (ETDEWEB)

    Lu Wei [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)]. E-mail: tjluwei@163.com

    2007-03-15

    Owing to the rapid development of economy and the stable improvement of people's living standard, central air conditioning units are broadly used in China. This not only consumes large energy, but also results in adverse energy-related environmental issues. Energy efficiency standards are accepted effective policy tools to reduce energy consumption and pollutant emissions. Recently, China issued two national energy efficiency standards, GB19577-2004 and GB19576-2004, for vapor compression central air conditioning units for the first time. This paper first reviews the two standards, and then establishes a mathematic model to evaluate the potential energy savings and environmental impacts of the standards. The estimated results indicate implementing these standards will save massive energy, as well as benefit greatly to the environment. Obviously, it is significant to implement energy efficiency standards for central air conditioning units in China.

  15. Experimental and statistical study of the influence of broken up particles and air content on the compressive strength of concretes

    International Nuclear Information System (INIS)

    Companies in Algeria have restricted budgets devoted to the formulation of concrete. Therefore, very few research studies are interested by the concrete composition in accordance to its purpose. Hence, this work is a part of an approved research program assigned to clarify the impact of certain parameters on the quality of concrete. This experimental program consists of more than 700 cylindrical specimens of 16x32 cm that were made using local materials. Excluding the durability indicators towards the concrete, the compressive strength is the most significant property to be considered (Mounanga et al., 2006). The obtained results concern consistency and content air propertiesof the concrete at fresh state and compressive strength of hardened concrete at 28 days. Thus, the influence of the air content percentage on the concrete consistency is studied. Moreover, the influence of these two parameters on the compressive strength of the hardened concrete is also presented. The experimental results obtained constitute a data bank, which allows comparing through a statistical analysis, the model established by Feret (Baron and Ollivier, 1996) and the results of the tests. (author)

  16. Evaluering af VIFT

    DEFF Research Database (Denmark)

    Pedersen, Michael Svendsen

    & Nordsjælland, og CPH West med støtte fra Undervisningsministeriets pulje til udvikling af videncenterfunktioner.   Evalueringen, der er gennemført af lektor Michael Svendsen Pedersen (Evaluator), Institut for Pædagogik og Uddannelsesforskning, Roskilde Universitet, i perioden april 2008 - oktober 2009, har......Denne rapport indeholder en ekstern evaluering af aktiviteter i VIFT, Videncenter for bedre undervisning af tosprogede elever, der er etableret som et samarbejde mellem Videncenter for tosprogethed & interkulturalitet (UC2) ved Professionshøjskolen København (UCC), tidligere CVU København...... været opdelt i to faser: En kvalitetssikrende følgeevaluering og en afsluttende indikatorbaseret evaluering, og denne rapport er opdelt i to hovedafsnit der indeholder resultaterne af hver af de to typer evaluering....

  17. Annual performance investigation and economic analysis of heating systems with a compression-assisted air source absorption heat pump

    International Nuclear Information System (INIS)

    Highlights: • Optimal compression ratio of CASAHP is obtained for the maximum energy saving rate. • Annual performance is improved by 10–20% compared to ASAHP without compression. • Energy saving rate is 17.7–29.2% and investment is reduced to 30–60% for CASAHP. • Both compression and partial-design enhance the economy with given energy saving. • Payback time is reduced from 12–32 to 3–6 years by compression and partial-design. - Abstract: The compression-assisted air source absorption heat pump (CASAHP) is a promising alternative heating system in severe operating conditions. In this research, parameter studies on the annual performance under various compression ratios (CRs) and source temperatures are performed to achieve the maximum energy saving rates (ESRs). Economic analyses of the CASAHP under different CRs and partial-design ratios are conducted to obtain an optimal design that considers both energy savings and economy improvements. The results show that the optimal CR becomes higher in colder regions and with lower heat source temperatures. For a source temperature of 130 °C, the optimal CR values in all of the cities are within 2.0. For source temperatures from 100 to 130 °C, the maximum ESR is in the range of 17.7–29.2% in the studied cities. The efficiency improvement rate (EIR) caused by compression in a severe source condition can reach 10.0–20.0%. From the viewpoint of economy, the relative investment of CASAHP is reduced to 30–60% with a CR of 2.0–3.0. With a 2–6% sacrifice in ESR, the payback period can be reduced from 12–32 to 5–9 years using compression. Partial-design of the CASAHP can further reduce the payback period to 3–6 years with a partial-design ratio of 50% and a CR of 2.8. Additionally, CRs and partial-design ratios are designed comprehensively by seeking the maximum ESR for a given acceptable payback period

  18. ARCgame - gamification af undervisning

    DEFF Research Database (Denmark)

    Jensen, Camilla Gyldendahl

    2014-01-01

    Gamification er et begreb, der anvendes til at beskrive brugen af spilelementer i andre miljøer for at forbedre brugernes oplevelse. Følgende tekst har til formål at behandle emnet i forhold til af opnå en forståelse for de elementer der indvirker på en ”gamification af et undervisningsforløb”, her...

  19. Konstruktion af transducer

    DEFF Research Database (Denmark)

    Henriksen, Lars; Nielsen, Martin Pram

    Formålet med dette midtvejsprojekt er at udarbejde en transducer til måling af pressers stivhed. Dette er gjort på baggrund af en gennemgang af både presse- og stativ-typer samtidig med at udbøjningssituationen beskrives. Der introduceres en ide, der udgør grundkonceptet for opmålingsproceduren o...... færdige transducer – Load cellen. Strain gauge sørger for dataopsamlingen fra load cellen. Disse kalibreres således at transduceren er klar til de videre målinger der ligger i forlængelse af dette projekt....

  20. Raman af hvide pigmenter

    DEFF Research Database (Denmark)

    Reeler, Nini Elisabeth Abildgaard; Nielsen, Ole Faurskov; Sauer, Stephan P. A.;

    2013-01-01

    Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter.......Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter....

  1. Evaluering af virkninger af omprioriteringsloven fra 2000

    DEFF Research Database (Denmark)

    Vestergaard, Hedvig

    , bliver i stand til at tiltrække bredere grupper af beboere. Rapporten indeholder en evaluering af, hvordan tre udvalgte bebyggelser har grebet forbedringsprojekterne an. Det drejer sig om Bispehaven i Århus Kommune, Vejleåparken i Ishøj Kommune og Tingbjerg i Københavns Kommune. Den overordne konklusion...... er, at en fysisk renovering med reelle forbedringer af bebyggelsernes oplevelsesmæssige og æstetiske kvaliteter er helt afgørende for en imageforbedring. Men ligeså afgørende er det sideløbende og vedholdende at gennemføre kulturelle og sociale udviklingsindsatser, der sikrer beboerne et bedre liv i...

  2. Optimization of diesel engine performances for a hybrid wind-diesel system with compressed air energy storage

    International Nuclear Information System (INIS)

    Electricity supply in remote areas around the world is mostly guaranteed by diesel generators. This relatively inefficient and expensive method is responsible for 1.2 million tons of greenhouse gas (GHG) emission in Canada annually. Some low- and high-penetration wind-diesel hybrid systems (WDS) have been experimented in order to reduce the diesel consumption. We explore the re-engineering of current diesel power plants with the introduction of high-penetration wind systems together with compressed air energy storage (CAES). This is a viable alternative to major the overall percentage of renewable energy and reduce the cost of electricity. In this paper, we present the operative principle of this hybrid system, its economic benefits and advantages and we finally propose a numerical model of each of its components. Moreover, we are demonstrating the energy efficiency of the system, particularly in terms of the increase of the engine performance and the reduction of its fuel consumption illustrated and supported by a village in northern Quebec. -- Highlights: → The Wind-Diesel-Compressed Air Storage System (WDCAS) has a very important commercial potential for remote areas. → The WDCAS is conceived like the adaptation of the existing engines at the level of the intake system. → A wind turbine and an air compression and storage system are added on the diesel plant. → This study demonstrates the potential of WDCAS to reduce fuel consumption and increase the efficiency of the diesel engine. → This study demonstrates that we can expect savings which can reach 50%.

  3. Forbrug af oplevelser – oplevelser af forbrug

    DEFF Research Database (Denmark)

    Jantzen, Christian

    2011-01-01

    Vi lever i et overflodssamfund, hvor det er svært at komme i tanker om noget, vi mangler. Men også i en ”glædesløs økonomi”, hvor vi ikke bliver berusende lykkelige af at spise os mætte eller smide det snavsede tøj i en vaskemaskine, som vasker det renere end rent, uden at vi behøver røre en finger...... kunne mærkes i form af nydelse og sanseligt eller følelsesmæssigt nærvær i situationen her og nu....

  4. Emission af ammoniak fra landbruget

    DEFF Research Database (Denmark)

    Andersen, J. M.; Sommer, S. G.; Hutchings, N. J.;

    Denne faglige redegørelse er en del af 4 faglige redegørelser: 1: Emmission af ammoniak fra landbruget - status og kilder, 2: Teknologiske muligheder for reduktion af ammoniakfordampningen fra landbruget, 3: Natur- og miljøeffekter af ammoniak, (4): Økonomiske vurderinger af tiltag til reduktion ...

  5. Coaching af dit studieliv

    DEFF Research Database (Denmark)

    Hansen, Rasmus Thorning

    2008-01-01

    En generel beskrivelse af de problemer specialestuderende sidder med og hvorledes coaching kan hjælpe med at (gen)skabe motivation og fokus......En generel beskrivelse af de problemer specialestuderende sidder med og hvorledes coaching kan hjælpe med at (gen)skabe motivation og fokus...

  6. Redesign af logistiksystemet

    DEFF Research Database (Denmark)

    Bjarnø, Ole-Christian; Johannsen, Bjørn

    1997-01-01

    Brüel og Kjær har gennem en årrække arbejdet med en strategi for redesign af logistiksystemet, en høj grad af outsourcing samy direkte leverancer til end-user. Med udgangspunkt i koncepterne for Business Reengineering. Supply Chain Management og kompleksitetsanalyse introduceres problemstillingen...

  7. Kvalitetssikring af pressvejseprocessen

    DEFF Research Database (Denmark)

    Rasmussen, Mogens H.

    Det oprindelige formål med dette arbejde var udvikling af procesovervågning til pressvejsning ved en udvalgt hovedgeometri. Hovedgeometrien, ring/rør geometrien i materialekombinationerne stålring til tinbronzerør, blev valgt efter en forundersøgelse. På baggrund af et litteraturstudie samt indle...

  8. Administration af informationsmodeller

    DEFF Research Database (Denmark)

    Hundebøl, Jesper

    2013-01-01

    En informationsmodel er i denne sammenhæng en digital repræsentation af et givent byggeri. Både offentlige og private bygherrer anvender informationsmodeller, når der 'bygges digitalt'. I denne artikel undersøges det, hvilke konkrete udfordringer der følger af digitaliseringen, hvor gennemgribend...

  9. Anvendelse af genmodificerede planter

    DEFF Research Database (Denmark)

    Møller, F.

    I rapporten vurderes mulighederne for at gennemføre velfærdsøkonomiske analyser af anvendelsen af genmodificerede planter. Der gøres rede for kravene til konse-kvensbeskrivelsen og for mulighederne for at prissætte såvel de markedsrelaterede som de ikke-markedsrelaterede konsekvenser. Mulighederne...

  10. Petrologic and petrophysical evaluation of the Dallas Center Structure, Iowa, for compressed air energy storage in the Mount Simon Sandstone.

    Energy Technology Data Exchange (ETDEWEB)

    Heath, Jason E.; Bauer, Stephen J.; Broome, Scott Thomas; Dewers, Thomas A.; Rodriguez, Mark Andrew

    2013-03-01

    The Iowa Stored Energy Plant Agency selected a geologic structure at Dallas Center, Iowa, for evaluation of subsurface compressed air energy storage. The site was rejected due to lower-than-expected and heterogeneous permeability of the target reservoir, lower-than-desired porosity, and small reservoir volume. In an initial feasibility study, permeability and porosity distributions of flow units for the nearby Redfield gas storage field were applied as analogue values for numerical modeling of the Dallas Center Structure. These reservoir data, coupled with an optimistic reservoir volume, produced favorable results. However, it was determined that the Dallas Center Structure cannot be simplified to four zones of high, uniform permeabilities. Updated modeling using field and core data for the site provided unfavorable results for air fill-up. This report presents Sandia National Laboratories' petrologic and petrophysical analysis of the Dallas Center Structure that aids in understanding why the site was not suitable for gas storage.

  11. Hormonforstyrrende effekter af kombinationer af pesticider

    DEFF Research Database (Denmark)

    Vinggaard, Anne Marie; Hass, Ulla; Nellemann, Christine;

    Resumé: Hvad sker der, når vi mennesker udsættes for en cocktail af hormonforstyrrende pesticider gennem kosten? Miljøstyrelsen har undersøgt pesticidblandinger i cellekulturer og i dyreforsøg for at vurdere samspillet mellem stofferne. Undersøgelserne har fokuseret på østrogene og antiandrogene...

  12. Rådgivning af storforbrugere af alkohol

    DEFF Research Database (Denmark)

    Beich, Anders

    1996-01-01

    målsætning for ændring af drikkevaner forbliver patientens. Stort alkoholforbrug er en underdiagnosticeret tilstand. I gængs praksis erkendes mindre end 25%. Det diskuteres, hvornår det er acceptabelt, at lægen sætter dagsordenen for konsultationen ved uopfordret at bringe alkohol på bane. Udgivelsesdato...

  13. Study and design of a hybrid wind-diesel-compressed air energy storage system for remote areas

    International Nuclear Information System (INIS)

    Remote areas around the world predominantly rely on diesel-powered generators for their electricity supply, a relatively expensive and inefficient technology that is responsible for the emission of 1.2 million tons of greenhouse gas (GHG) annually, only in Canada . Wind-diesel hybrid systems (WDS) with various penetration rates have been experimented to reduce diesel consumption of the generators. After having experimented wind-diesel hybrid systems (WDS) that used various penetration rates, we turned our focus to that the re-engineering of existing diesel power plants can be achieved most efficiently, in terms of cost and diesel consumption, through the introduction of high penetration wind systems combined with compressed air energy storage (CAES). This article compares the available technical alternatives to supercharge the diesel that was used in this high penetration wind-diesel system with compressed air storage (WDCAS), in order to identify the one that optimizes its cost and performances. The technical characteristics and performances of the best candidate technology are subsequently assessed at different working regimes in order to evaluate the varying effects on the system. Finally, a specific WDCAS system with diesel engine downsizing is explored. This proposed design, that requires the repowering of existing facilities, leads to heightened diesel power output, increased engine lifetime and efficiency and to the reduction of fuel consumption and GHG emissions, in addition to savings on maintenance and replacement cost.

  14. Preliminary feasibility evalution of compressed air storage power systems. Volume II. Appendices, period June 1975--December 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-12-01

    Interest in compressed air storage has been developing in Sweden, Finland, Denmark, England, and France, as well as the United States. One commercial unit is under construction in Huntorf, West Germany. Compressed air for peak power can be stored either in natural or man-made caverns. Only new excavations in hard rock down to depths of about 2500 feet are considered in this report. In 1974, conditions for underground storage were discussed in a Geological Survey of Potential Cavern Areas in New England, referred to as the CAINE report. In this survey of the northeast region, the rest of the corridor between Washington and Boston has been added. The rock formations in the entire area of about 45,000 square miles are evaluated. The physical properties of rocks and criteria for their evaluation in underground openings are discussed. Methods of rock excavation and the basis for selecting areas are considered. Information on bedrock units along the corridor is reviewed. A list of favorable rock formations is included.

  15. Performance assessment and optimization of a combined heat and power system based on compressed air energy storage system and humid air turbine cycle

    International Nuclear Information System (INIS)

    Highlights: • A combined heat and power system based on CAES and HAT is proposed. • The design and modeling of the CAES–HAT based CHP system are laid out. • The performance assessment of the proposed system is carried out. • The system optimization is conducted to decide the maximum conditions. - Abstract: Renewable energy based power sources have grown rapidly in the past few years owing to the dual constraint of climate change and pollution control. Compressed air energy storage (CAES), as a large-scale energy storage system (ESS) technology, has huge potential to manage the intermittent renewable energy based power sources effectively. However, the compression heat generated during charge and waste heat carried in turbine exhaust during discharge are not fully recuperated in current stage. A combined heat and power (CHP) system consisting of a CAES system and a humid air turbine (HAT) system is proposed to utilize the both types of heat energy. The proposed system can boost the power output, enhance performance and improve efficiency through a simultaneous supply of power and heat. The thermodynamic analysis shows that the expansion train power can be improved about 26% compared with the conventional CAES system. The parametric analysis reveals that the exergy efficiency increases with the turbine inlet temperature (TIT) of high pressure turbine (HPT) and inlet pressure of low pressure turbine (LPT), but decreases with the TIT of LPT, L/G ratio and dry air inlet temperature of saturator. Meanwhile, the system optimization is carried out via particle swarm optimization (PSO) to determine the maximum power and exergy efficiency conditions

  16. Ledelse af vejledelse

    DEFF Research Database (Denmark)

    Andersen, Frode Boye

    2014-01-01

    Denne artikel handler om samspillet mellem vejledning som funktion, ledelse og de organisatoriske processer i skolen. Det er artiklens ambition at argumentere for nogle særlige ledelsesmæssige fokuseringer i en skoleorganisation hvor vejledningsfunktioner af forskellige grunde ser ud til at skulle...... derfor indledningsvist et billede af hvordan man kan forstå ledelsesbetingelserne i en organisation som skolen: uden en sådan forståelsesramme risikerer konteksten for vejledningsfunktionerne at blive en art black box hvor ledelseskraften bliver prisgivet tilfældigheder. Omvendt er valget af...

  17. CLEAN-AIR heat pump. Reduced energy consumption for ventilation in buildings by integrating air cleaning and heat pump. Final Report; CLEAN-AIR heat pump - Reduceret energiforbrug til ventilation af bygninger ved luftrensning integreret med luft varmepumpe. Slut rapport

    Energy Technology Data Exchange (ETDEWEB)

    Fang, L.; Olesen, Bjarne W.; Molinaro, G.; Simmonsen, P.; Skocajic, S. [Danmarks Tekniske Univ. Institut for Byggeri og Anlaeg, Lyngby (Denmark); Hummelshoej, R.M.; Carlassara, L. [COWI A/S, Lyngby, (Denmark); Groenbaek, H.; Hansen, Ole R. [Exhausto A/S, Langeskov (Denmark)

    2011-07-01

    This report summarizes task 1 of the Clean Air Heat Pump project - modelling and simulation on energy savings when using the clean air heat pump for ventilation, air cleaning and energy recovery. The total energy consumption of the proposed ventilation systems using clean air heat pump technology was calculated by a theoretical model and compared with the reference ventilation systems (conventional ventilation systems). The energy compared between the two systems includes energy used for heating, cooling and fan. The simulation and energy saving calculation was made for the application of the clean air heat pump in three typical climate conditions, i.e. mild-cold, mild-hot and hot and wet climates. Real climate data recorded from three cities in 2002 was used for the calculation. The three cities were Copenhagen (Denmark), Milan (Italy) and Colombo (Sir Lanka) which represent the above three typical climate zones. For the Danish climate (the mild cold climate), the calculations show that the ventilation system using clean air heat pump technology can save up to 42% of energy cost in winter compared to the conventional ventilation system. The energy saving in summer can be as high as 66% for the ventilation system with humidity control and 9% for the ventilation system without the requirement of humidity control. Since the Danish summer climate is very mild, over 80% of the yearly energy consumption for ventilation is used during winter season. It is, therefore, estimated that more than 35% annual energy saving for ventilation is expected in Denmark using the clean air heat pump ventilation technology. For the mild hot climate, e.g. the Italian climate, the calculations show that up to 63% of the energy saving can be achieved in summer season. For the winter mode, 17% reduction of the energy cost can be expected for the domestic use. For industrial use, the energy cost of the clean air heat pump may not be favourable due to the industrial price of gas in Italy is

  18. Termisk forgasning af biomasse

    DEFF Research Database (Denmark)

    Indlæggene i referatet er gengivet efter båndoptagelser. Der er dog foretaget nogle enklte omskrivninger af hensyn til læseligheden. Foredragsholdernes overheads er endvidere blevet lagt ind i referatet....

  19. Kritik af pseudovidenskab censureret

    DEFF Research Database (Denmark)

    Emmeche, Claus

    2014-01-01

    Weekendavisen har afvist at bringe et indlæg af Jørgen Øllgaard om deres egen dækning af Helmuth Nyborg og sagen om hans forskning i IQ, som UVVU har dømt uredelig. Måske er UVVU bedre til at tage sig af bevidst fusk i god normal videnskab end til sager, som angår "patologisk videnskab" ("fringe...... science") med varierende grader af marginalitet. Dette begreb kan både dække hvad Kuhn ville kalde "revolutionær videnskab", som blot endnu ikke er anerkendt men starter med nogle få forskeres vilde ideer, og så især det, som dårligt nok kan testes, efterprøves, og som måske langsomt opløses hvis det...

  20. Supervision af psykoterapi

    DEFF Research Database (Denmark)

    SUPERVISION AF PSYKOTERAPI indtager en central position i uddannelsen og udviklingen af psykoterapeuter. Trods flere lighedspunkter med psykoterapi, undervisning og konsultation er psykoterapisupervision et selvstændigt virksomhedsområde. Supervisor må foruden at være en trænet psykoterapeut kende...... supervisionens rammer og indplacering i forhold til organisation og samfund. En række kapitler drejer sig om supervisors opgaver, roller og kontrolfunktion, supervision set fra supervisandens perspektiv samt betragtninger over relationer og processer i supervision. Der drøftes fordele og ulemper ved de...... forskellige måder, hvorpå en sag kan fremlægges. Bogens første del afsluttes med refleksioner over de etiske aspekter ved psykoterapisupervision. Bogens anden del handler om de særlige forhold, der gør sig gældende ved supervision af en række specialiserede behandlingsformer eller af psykoterapi med bestemte...

  1. Test af Software

    DEFF Research Database (Denmark)

    Dette dokument udgør slutrapporten for netværkssamarbejdet ”Testnet”, som er udført i perioden 1.4.2006 til 31.12.2008. Netværket beskæftiger sig navnlig med emner inden for test af indlejret og teknisk software, men et antal eksempler på problemstillinger og løsninger forbundet med test af...... administrativ software indgår også. Rapporten er opdelt i følgende 3 dele: Overblik. Her giver vi et resumé af netværkets formål, aktiviteter og resultater. State of the art af software test ridses op. Vi omtaler, at CISS og netværket tager nye tiltag. Netværket. Formål, deltagere og behandlede emner på ti...

  2. Bearbejdning af Luhmanns organisationsteori

    DEFF Research Database (Denmark)

    Mortensen, Nils

    Som titlen siger, er det en gennemgang/præsertation af Luhmanns organisationsteori. Der er lagt særlig vægt på emnerne beslutning, ledelse opg forandring......Som titlen siger, er det en gennemgang/præsertation af Luhmanns organisationsteori. Der er lagt særlig vægt på emnerne beslutning, ledelse opg forandring...

  3. Performance study on three-stage power system of compressed air vehicle based on single-screw expander

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power system.Three different structure styles were presented,and the studies on the power performance and the distribution of expansion ratios between stages were carried out by programming and mathematical modeling of each style.Research results indicated that the best matches of expansion ratios with equal heat temperature for the air tank of pressure 30 MPa were seven-five-three for"first-stage heating"style,eight-five-three for"two-stage heating"style and five-five-four for"three-stage heating"style,respectively.Results also showed that heating up inlet air or increasing the expander efficiency might improve the power performance.The output power of the"two-stage heating"style is far higher than that of"first-stage heating"style and is a little lower than that of"three-stage heating"style.The new system showed good structure and power performances.

  4. Sundhedseffekter af luftforurening-beregningspriser

    DEFF Research Database (Denmark)

    Andersen, M. S.; Frohn, L. M.; Jensen, S. S.;

    Denne rapport afrapporterer det fortsatte arbejde med udvikling af miljøøkonomiske beregningspriser. På grundlag af EcoSense 4.0 fra ExternE-projektet, er der foretaget nye beregninger af eksternaliteter ved luftforurening med sundhedseffekter. Samtidig giver rapporten en vurdering af luftspredni...

  5. Homemade Firearm Suicide With Dumbbell Pipe Triggering by an Air-Compressed Gun: Case Report and Review of Literature.

    Science.gov (United States)

    Le Garff, Erwan; Delannoy, Yann; Mesli, Vadim; Berthezene, Jean Marie; Morbidelli, Philippe; Hédouin, Valéry

    2015-12-01

    Firearm suicides are frequent and well described in the forensic literature, particularly in Europe and the United States. However, the use of homemade and improvised firearms is less well described. The present case reports a suicide with an original improvised gun created using an air-compressed pellet gun and a dumbbell pipe. The aims of this study were to describe the scene, the external examination of the corpse, the body scan, and the autopsy; to understand the mechanism of death; and to compare the results with a review of the forensic literature to highlight the epidemiology of homemade firearm use, the tools used for homemade and improvised firearms in suicides versus homicides, and the manners in which homemade firearms are used (homicide or suicide, particularly in complex suicide cases). PMID:26375571

  6. Spectral broadening and temporal compression of ∼ 100 fs pulses in air-filled hollow core capillary fibers.

    Science.gov (United States)

    Li, C; Rishad, K P M; Horak, P; Matsuura, Y; Faccio, D

    2014-01-13

    We experimentally study the spectral broadening of intense, ∼ 100 femtosecond laser pulses at 785 nm coupled into different kinds of hollow core capillary fibers, all filled with air at ambient pressure. Differently from observations in other gases, the spectra are broadened with a strong red-shift due to highly efficient intrapulse Raman scattering. Numerical simulations show that such spectra can be explained only by increasing the Raman fraction of the third order nonlinearity close to 100%. Experimentally, these broadened and red-shifted pulses do not generally allow for straightforward compression using, for example, standard chirped mirrors. However, using special hollow fibers that are internally coated with silver and polymer we obtain pulse durations in the sub-20 fs regime with energies up to 300 μJ. PMID:24515074

  7. Review of Compressed Air Energy Storage System%压缩空气蓄能(CAES)系统综述

    Institute of Scientific and Technical Information of China (English)

    肖定垚; 王承民; 衣涛; 谢宁; 史伟伟

    2014-01-01

    介绍了一种新型的大规模蓄能技术——压缩空气蓄能(Compressed Air Energy Storage,CAES),CAES系统响应快、容量大、成本低、寿命长,逐渐成为了全球第二大蓄能技术.根据CAES系统的容量不同,将CAES系统划分为大型CAES、小型CAES和微型CAES 3种,并针对3种不同容量级的CAES,详细介绍了其组成及现状,对技术特点与难点和应用领域及场景进行了分析与概述.对CAES系统的研究方向与发展前景进行了展望.

  8. Storage of compressed air - Optimisation and measurement of an existing project example; Druckluftspeicherung: Optimierung / Ausmessung bestehendes Projektmuster

    Energy Technology Data Exchange (ETDEWEB)

    Brueckmann, P. [Brueckmann Elektronik, Davos Dorf (Switzerland); Cyphelly, I. [Cyphelly and Cie, Les Brenets (Switzerland)

    2007-06-15

    This short final report for the Swiss Federal Office of Energy (SFOE) deals with an additional project that augmented an earlier report on a compressed-air energy storage system. First tests are reported on that revealed that the chosen heat exchanger fulfils the thermal expectations with substantial reserves. Certain effects concerning the liquid piston system are described which showed that further development of the test infrastructure were required. This project was launched to further examine these problems. Difficulties with the liquids available which prohibited the intended exact series of measurements are commented on. The authors note that independent investigations by the Austrian company LINDE came to the same conclusions, thus confirming the function of the heat exchanger.

  9. Effective medium method of slightly compressible elastic media permeated with air-filled bubbles

    Institute of Scientific and Technical Information of China (English)

    QIN Bo; LIANG Bin; ZHU Zhe-min; CHENG Jian-chun

    2006-01-01

    An effective medium method is developed for the slightly compressible elastic media permeated with airfilled bubbles,according to the nonlinear oscillation of the bubble,which happens when compressional wave travels through the porous media.The effective Lame coefficients of the porous medium and the nonlinear elastic wave equation are deduced,based on the fact that the micro-unit of the effective medium should have the same stress and strain as the micro-unit of the porous media.The linearized properties obtained by this method are in good agreement with the results of Gaunaurd's classic theory [Gaunaurd G.C.and (U)berall H.,J.Acoust.Soc.Am.,1978,63:1699-1711].Furthermore,the nonlinear coefficient,which is an important property of the porous media,can also be acquired by this method.

  10. Simulering af fossilt energiforbrug & emissioner af drivhusgasser

    DEFF Research Database (Denmark)

    Dalgaard, Tommy; Halberg, Niels; Fenger, J.

    2000-01-01

    Øget jordbehandling ved mekanisk ukrudtsbekæmpelse i det økologiske jordbrug har givet en forventning om et højere energiforbrug i økologisk end i konventionelt jordbrug. Beregninger viser imidlertid, at der på landsplan spares energi ved omlægning til økologisk jordbrug. Dette skyldes primært, a...... der i økologisk jordbrug ikke anvendes kunstgødning. Rapporten belyser effektive veje til at mindske energiforbrug og udledning af drivhusgasser, som at mindske produktionen, indføre mere energieffektive teknologier og evt. øge bioenergiproduktionen....

  11. Cost and time effective DSM on mine compressed air systems / R. Joubert

    OpenAIRE

    Joubert, Hercules Phillipus Roedolf

    2010-01-01

    Implementing demand side management (DSM) is expensive and often time consuming. Eskom grants subsidies for DSM projects based on the proposed savings. The subsidy granted is not always adequate to fund all the required control equipment to achieve the desired saving. This study focuses on alternative cost– and time–effective methods to implement DSM on gold mines, specifically on the compressed–air systems where the infrastructure is inadequate, worn out or outdated. The...

  12. COP Prediction of an ejector refrigeration cycle combined with a vapour compression cycle for automotive air conditioning

    Directory of Open Access Journals (Sweden)

    Nat Suvarnakuta

    2014-03-01

    Full Text Available This paper presents the COP prediction of an ejector refrigeration cycle combined with a vapour compression cycle for automotive air conditioning. Using computational fluid dynamics (CFD technique, the performance of an ejector was analyzed in term of the entrainment ratio (Rm and critical back pressure (CBP. The results from this study were compared with a previous study of combined ejector refrigeration system for automotive air conditioning application [1] which the entrainment ratio (Rm were predicted from one-dimensional (1-D equation. The performance of an ejector (Rm and CBP from CFD and onedimensional method were analyzed and used as database for a mathematical modeling. In order to predict the COP of the combined system, a set of mathematical equations was developed using EES. The operating conditions are chosen accordingly as, intercooler temperature between 15 ๐ C and 25 ๐ C, condenser temperature equal to 35 ๐ C and evaporator temperature equal to 5 ๐ C. However, when generator temperatures are 80 ๐ C, 85 ๐ C and 90 ๐ C, the results showed average relative errors of the COP of an ejector refrigeration cycle (COPej, between CFD and 1-D are 44.64%, 50.47% and 59.68% respectively, and between CFD and 1-D NEW are 1.54%, 0.08% and 6.49% respectively.

  13. Realisering af Vision 2020

    DEFF Research Database (Denmark)

    Bertelsen, Niels Haldor; Hansen, Ernst Jan de Place

    Repræsentanter for byggesektoren har på 11 dialogmøder drøftet Erhvervs- og Byggestyrelsens "Vision 2020 - Byggeri med mening". Drøftelserne førte til formulering af en lang række initiativforslag til realisering af visionen. Den mest centrale udfordring bliver at reducere fejl og mangler i...... byggeriet. Branchen lægger også vægt på, at styringen af Vision 2020s reaisering sker i byggesektoren. Initiativforslagene er i rapporten samlet under 3 hovedområder. Det første hovedområde lægger vægt på bygningerne, brugerbehov og det globale samfund. Det andet omhandler processen og leverancesystemet...

  14. AFS controlling algorithm

    Science.gov (United States)

    Liu, Hong; Jiang, Lanfang; Wang, Gengjie; Wang, Li

    2008-12-01

    Adaptive front lighting system (i.e., AFS) is the development trend of lighting system of motor vehicles. AFS means that headlamp can adjust beam direction to get best illumination according to road condition and its bodywork. The paper discusses the AFS key techniques: establishing calculation formulae of vehicle body state concerned road condition and steering state. Because of sensor technology limitations, it only can deal with inclination and turn of vehicle body state by means of sensor's signals. This paper studies the relationship between inclination and turn of the body and lamp lighting on the base of relative standards, and gives out the calculation formulae for the body and lamp lighting adjustment, also discusses its dynamical properties. The study is basic work for lighting adjustment automatically.

  15. Anvendeligheden af GIS

    DEFF Research Database (Denmark)

    Winstrup, Mie; Levin, Gregor

    2011-01-01

    Fragmentering af naturen er en trussel mod biodiversiteten, og etablering af økologiske forbindelser/korridorer mellem naturområderne er én måde hvorved nedgangen i biodiversitet kan stoppes. Med Næstved Kommune som case-område har jeg undersøgt, hvordan analyser i GIS kan bruges til at udvælge...... omdannet til reelle korridorer, hvor bredden afhænger af arealdækket som forbindelserne krydser. I implementerings øjemed er det anvendeligt at vide om nogle forbindelser er særlig vigtige for at skabe mere sammenhængende natur. GIS er anvendeligt hertil, idet GIS kan bruges til at bestemme den enkelte...

  16. Compressed-Air Energy Storage: Preliminary design and site development program in an aquifer. Volume 7: Environmental, safety, and licensing considerations

    Science.gov (United States)

    1981-07-01

    The behavior and suitability of aquifers as compressed-air energy storage (CAFS) sites was studied. The probability, severity, and recommended control measures for the environmental and safety impacts that could result from the construction and operation of a CAES facility are described. The permits and approvals that would be required and the time estimated for their acquisition are also described.

  17. Evaluering af sunddialog

    DEFF Research Database (Denmark)

    Wentzer, Helle; Kjærgaard Thorsen, Mille

    Kroniske patienter oplever øget kontrol med deres sygdom, og forebyggelsessygeplejersker får styrket fagligheden og samarbejdet med patienternes egen læge via it-støttede forebyggelsessamtaler. Det viser en evaluering af værktøjet Sunddialog.......Kroniske patienter oplever øget kontrol med deres sygdom, og forebyggelsessygeplejersker får styrket fagligheden og samarbejdet med patienternes egen læge via it-støttede forebyggelsessamtaler. Det viser en evaluering af værktøjet Sunddialog....

  18. Transient characteristics and performance analysis of a vapor compression air conditioning system with condensing heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ming Liu; Wu, Jing Yi; Xu, Yu.Xiong; Wang, Ru Zhu [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240 (China)

    2010-11-15

    The objective of this study is to evaluate the influence of condensing heat recovery on the dynamic behavior and performance of air conditioners. The article includes a test procedure utilized to evaluate the condensing heat recovery system, relevant experimental results, a detail analysis of the mechanisms, and improvement measure on such a system. The experimental results indicate that although the condensing heat recovery has a negative effect on the cooling capacity at the start of the heat recovery process, the average cooling coefficient of performance (COP) of the system can be improved. The study also incorporates a control scheme of the electronic expansion valve (EEV) of the condensing heat recovery system. The experimental comparison between the EEV and the thermostatic expansion valve (TEV) demonstrates that the EEV has better performance in both stability and efficiency in the condensing heat recovery system. (author)

  19. Et pust af storhed

    DEFF Research Database (Denmark)

    Kural, René

    2005-01-01

    I forsommeren dette år gik Council of Europe's Museum Prize 2005 til det Byzantinske Museum i Thessaloniki, Makedonien. Prisen er uddelt siden 1977 og tildelt museer, der har bidraget betydeligt til formidlingen af den europæiske kulturarv. Forfatteren har vurderet, hvad der fik juryen i...

  20. Benchmark af erhvervsuddannelserne

    DEFF Research Database (Denmark)

    Bogetoft, Peter; Wittrup, Jesper

    I dette arbejdspapir diskuterer vi, hvorledes de danske erhvervsskoler kan benchmarkes, og vi præsenterer resultaterne af en række beregningsmodeller. Det er begrebsmæssigt kompliceret at benchmarke erhvervsskolerne. Skolerne udbyder en lang række forskellige uddannelser. Det gør det vanskeligt at...

  1. Anskydning af vildt

    DEFF Research Database (Denmark)

    Noer, H.; Madsen, J.; Hartmann, P.; Kanstrup, N.; Kjær, T.

    indsamlet i samarbejde mellem Danmarks Miljøundersøgelser og Skov- og Naturstyrelsen. Desuden har Danmarks Jægerforbund og en række andre institutioner, organisationer og enkeltpersoner bidraget til undersøgelserne. Omfanget af anskydninger for forskellige vildtarter I februar 1998 blev 127 gråænder...

  2. Inklusion af utilpassede unge

    DEFF Research Database (Denmark)

    Petersen, Karen Bjerg

    2015-01-01

    Anholt-projektet repræsenterer en alternativ pædagogisk interventionsform for utilpassede og sårbare unge. Projektet, der i en årrække har været afprøvet af ungdomsskoler og ungdomsorganisationer i Danmark, Tyskland, Østrig, Spanien, Portugal og Italien, bygger på tanker om erfaringsbaseret, ufor...

  3. Definition af et landdistrikt

    DEFF Research Database (Denmark)

    Søgaard, Villy

    2008-01-01

    Forskellige lande arbejder med meget forskellige definitioner af begrebet landdistrikt. Arbejdspapiret diskuterer først en række generelle krav til definitioner og anbefaler på den baggrund konkrete justeringer i forhold til den hidtidige danske praksis på området. Arbejdspapiret er blevet til i...

  4. Optimal indretning af biblioteksrummet

    DEFF Research Database (Denmark)

    Rasmussen, Pernille Gaardsted; Hansen, Lotte; Nielsen, Bo Gerner

    2012-01-01

    I forbindelse med kurset ”Brugeradfærd og interaktive informationsrum” på 5. semester ved Det Informationsvidenskabelige Akademi (IVA) har vi foretaget et observationsstudie af studerendes aktiviteter og ejendele på Aalborg Universitetsbibliotek (AUB). Formålet med projektopgaven var at undersøge...

  5. Brug af forskningsbaseret viden

    DEFF Research Database (Denmark)

    Næsby, Torben

    2013-01-01

    Artiklen anvender LP-modellen som et eksempel på, hvordan forskningsbaseret viden kan anvendes til kvalitetsudvikling. Ikke organiseret som top-styrede projekter, heller ikke som ”bottom-up- styrede”, men som en kombination af disse. Med eksempler fra den forskningsbaserede viden fra empirien, der...

  6. Udforskning af journalistiske moralnormer

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    2010-01-01

    Kirsten Mogensen beskriver professionelle journalistiske normer. Med udgangspunkt i amerikansk tv's dækning af begivenhederne 11. september kombinerer Kirsten Mogensen kvalitative interviews og tekstanalyse for på den måde at beskrive professionelle journalistiske normer. Metoden er en kombination...

  7. Energirenovering af parcelhuse

    DEFF Research Database (Denmark)

    Aggerholm, Søren

    I rapporten beskrives et demonstrationsprojekt, som viser, at det er muligt at opnå yderligere energibesparelse i parcelhuse, der i forvejen opfylder kravene for at få udstedt energiattest. Projektet er gennemført i tre parcelhuse i Toftlund, som en del af Brundtlandbyprojektet. Energirenoveringe...

  8. Anmeldelse af: Gruppepsykologi

    DEFF Research Database (Denmark)

    Christensen, Bodil

    2009-01-01

    , kreativitet og nytænkning. Det er her, videnskabens virkelige fremskridt sker.” Sådan lyder et citat af Albert Einstein, som Lars Svedberg bruger for at sætte sin faglige fremstilling om gruppepsykologi i perspektiv. Gruppeorganisationen er nemlig ofte rum for/ eller kan være rum for denne synergieffekt, der...

  9. 化工型空分设备内压缩流程选择%Selection of inner compression process for chemical type air separation plant

    Institute of Scientific and Technical Information of China (English)

    蒋旭

    2011-01-01

    介绍化工型空分设备的3种典型内压缩流程形式:空气循环单泵流程、空气循环双泵流程、氮气循环单泵流程,结合内压缩流程空分设备的一般考核标准,比较了3种流程形式的流程设计组织、综合能耗、精馏效果、运行安全、操作维护等方面,说明用户应合理选择适合产品规格要求的内压缩空分流程。%Here, 3 typical types of inner compression process for chemical type air separation plant are introduced: Air circulation single-pump process, air circulation dual-pump process, and nitrogen circulation single-pump process, and in combination with the general examination standards of inner compression process air separation plant the process design organization, comprehensive energy consumption, distillation effect, operation safety, operation and maintenance of the 3 types of process are compared, which indicates that the user shall rationally select the inner compression air separation process which meets the product specification.

  10. Nibe Bredning, klapning af oprensningsmaterialer og vurdering af sedimentspredning

    DEFF Research Database (Denmark)

    Larsen, Torben; Bentzen, Thomas Ruby

    Formålet med undersøgelsen er at beregne spredningen af klapmateriale oprenset fra sejlrenden til Nibe samt Draget. Klappladsen for begge lokaliteter er umiddelbart nordvest for Klitgaard Hage. Beregningen er foretaget vha. af numerisk modellering af strømforhold samt sedimenttransport. Til formå...

  11. Applicability of thermal energy storage recycled ceramics to high temperature and compressed air operating conditions

    International Nuclear Information System (INIS)

    Highlights: • ACW ceramics have been successfully tested under ACAES operating conditions. • ACW ceramics have been successfully tested under gas turbine based CSP conditions. • Under 600 °C-30 bars of air, ACW ceramics Cp is slightly lowered by 5%. • Thermal conductivity of ACW ceramics is advantageously enhanced by 30%. - Abstract: Recycled ceramics made of inertized asbestos containing wastes have been submitted to high pressure/temperature cycling tests in the operating range of ACAES and CSP applications. Ten successive cycles between room conditions and 610 °C/30 bars for a cumulated duration of 2500 h lead to a validation of the ability of the material to resist to those constrains. The Wollastonite/Augite initial structure is gradually transformed in a unique Augite containing material. While mechanical parameters and density are unchanged, thermal capacity is reduced by 5% and thermal conductivity increased by 30%. This last result offers an advantageous way to enhance the thermal conductivity of those recycled ceramics, a key parameter to control the charge/discharge power in TES systems

  12. Thermodynamic analysis of an integrated energy system based on compressed air energy storage (CAES) system and Kalina cycle

    International Nuclear Information System (INIS)

    Highlights: • An integrated energy system based on CAES and Kalina cycle is proposed. • The design and modeling of the CAES–KCS6 system are laid out. • The energy analysis and exergy analysis of the proposed system are carried out. • A parametric analysis is conducted to examine their effect on system performance. - Abstract: High penetration of renewable power sources into power system leads to significant challenge in balancing of power generation and consumption due to the highly erratic nature of renewable energies. Integrating the energy storage system (ESS) with power system can weaken these negative effects effectively. Compressed air energy storage (CAES) system as one of the grid-scale ESS technologies has grown rapidly in the past few years. However, the temperature of exhaust from low pressure turbine during discharge process is still high enough to utilize. An integrated energy system consisting of a CAES system and a Kalina cycle system 6 (KCS6) is proposed to recover this waste heat. The thermodynamic analyses including energy analysis and exergy analysis are evaluated by using steady-state mathematical model and thermodynamic laws. The second law efficiency of the proposed CAES–KCS6 system can be improved nearly 4% compared to that of the single conventional CAES system. Meanwhile, the parametric analysis is also carried out to evaluate the effects of some key parameters on system performance, such as the turbine inlet temperature (TIT), inlet pressure of low pressure turbine and the air storage cavern temperature. Results show that all of these parameters have positive effect on system exergy efficiency

  13. Dannelsen af den ansvarlige elev

    DEFF Research Database (Denmark)

    Larsen, Jesper

    2010-01-01

    Denne artikel handler om den del af lærergerningen, der har at gøre med udarbejdelse af elevplaner. Der tages udgangspunkt i en foucaultsk forståelse, hvor beskrivelsen af den enkelte elev udtrykker et særligt normativt ideal om, hvilke former for elevhed der er de ønskværdige i den danske...

  14. Vejledning i projektering af ventilationsrum

    DEFF Research Database (Denmark)

    Dinesen, J.

    vedligeholdelse. Vejledningens dimensioneringsforslag er baseret på et omfattende erfaringsmateriale, som er indsamlet dels af det rådgivende ingeniørfirma Crone & Koch, dels i forbindelse med det arbejde, der udføres af Byggeriets Indeklima Målestation (BIM). Ved bearbejdningen af materialet har civilingeniør...

  15. Udlejers godkendelse af ny erhvervslejer

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    2009-01-01

    I artiklen er taget udgangspunkt i den »klassiske« afståelsessituation, hvor en lejer vil afhænde den i de lejede lokaler drevne virksomhed, og lejeren har afståelsesret til en af udlejer godkendt lejer, uden at kravene til den ny lejer er specificeret. På baggrund af Vestre Landsrets dom af 9/2 ...

  16. The first and second law analysis of a grid connected photovoltaic plant equipped with a compressed air energy storage unit

    International Nuclear Information System (INIS)

    PV (Photovoltaic) plants are widely used to produce power in either large or small scales all around the world. In addition, CAES (compressed air energy storage) system has attracted considerable attention as one of the most efficient candidates for large scales energy storage applications in the recent years. In this work, detailed energy and exergy analysis of a 100 MWp (megawatt peak) grid connected PV plant equipped with a CAES system is carried out. The PV plant is assumed to be located in Brazil. The formulations related to the first and the second laws of thermodynamic for all components as well as detailed solar engineering formulations for both the PV farm and the solar heating unit are presented. The performance of the power plant is comprehensively investigated for one entire year in real circumstances. The results revealed that the energy and exergy efficiencies of the CAES system are very close and vary from 35% up to 65% during the year. Also, the annual average exergy and energy efficiencies of the power plant are calculated to be 17.9% and 16.2%, respectively. - Highlights: • This article presents a thorough thermodynamic analysis on a PV farm equipped with a CAES unit. • Energy performance of all components in the system are investigated. • Exergy analysis formulation for of all components in the system is given. • Energy and exergy destruction origins are found and reported. • Detailed energy and exergy efficiency report for the power plant and its subsystems is presented

  17. Inner Ear Barotrauma After Underwater Pool Competency Training Without the Use of Compressed Air Case and Review.

    Science.gov (United States)

    McIntire, Sean; Boujie, Lee

    2016-01-01

    Inner ear barotrauma can occur when the gas-filled chambers of the ear have difficulty equalizing pressure with the outside environment after changes in ambient pressure. This can transpire even with small pressure changes. Hypobaric or hyperbaric environments can place significant stress on the structures of the middle and inner ear. If methods to equalize pressure between the middle ear and other connected gas-filled spaces (i.e., Valsalva maneuver) are unsuccessful, middle ear overpressurization can occur. This force can be transmitted to the fluid-filled inner ear, making it susceptible to injury. Damage specifically to the structures of the vestibulocochlear system can lead to symptoms of vertigo, hearing loss, and tinnitus. This article discusses the case of a 23-year-old male Marine who presented with symptoms of nausea and gait instability after performing underwater pool competency exercises to a maximum depth of 13 feet, without breathing compressed air. Diagnosis and management of inner ear barotrauma are reviewed, as is differentiation from inner ear decompression sickness. PMID:27450603

  18. Anmeldelse af Evolution, Literature and Film

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh

    2011-01-01

    Diskussion af basisproblemer i evolutionær fiktionsteori med udgangspunkt i en anmeldelse af Evolution, Literature and Film......Diskussion af basisproblemer i evolutionær fiktionsteori med udgangspunkt i en anmeldelse af Evolution, Literature and Film...

  19. En genlæsning af John Rawls i lyset af hans diskussion af forholdet til fremtidige generationer

    DEFF Research Database (Denmark)

    Lübcke, Poul

    2009-01-01

    På grundlag af en konsekventialistisk rekonstruktion af Rawls' politiske position gøres der rede for Rawls eksplicitte og implicitte vurdering af vores ansvar over for fremtidige generationer......På grundlag af en konsekventialistisk rekonstruktion af Rawls' politiske position gøres der rede for Rawls eksplicitte og implicitte vurdering af vores ansvar over for fremtidige generationer...

  20. Aflivning af heste

    DEFF Research Database (Denmark)

    Karlshøj, Merete; Fredsbo, Louise; Buhl, Rikke

    2007-01-01

    Det er efterhånden sjældent at heste dør af alderdøm. Ofte må ejer træffe den vanskelige beslutning om at lade hesten aflive. Da der tit er tale om en kær ven, er hesteejeren følelsesmæssigt påvirket. Det er derfor afgørende, at aflivningen foretages fagligt korrekt og professionelt.......Det er efterhånden sjældent at heste dør af alderdøm. Ofte må ejer træffe den vanskelige beslutning om at lade hesten aflive. Da der tit er tale om en kær ven, er hesteejeren følelsesmæssigt påvirket. Det er derfor afgørende, at aflivningen foretages fagligt korrekt og professionelt....

  1. Opbygning af alliance

    DEFF Research Database (Denmark)

    Pedersen, Inge Nygaard

    2002-01-01

    Denne artikel er et forsøg på at bringe læseren med ind i atmosfæren, i oplevelsen og overvejelserne i forbindelse med opstart på et musikterapiforløb med en patient, som er meget svær at få kontakt med. Den er skrevet i et detaljerigt praksisnært sprog og har på én gang til for mål at starte på...... dokumentation af musikterapeutisk arbejde i børnepsykiatrien på musikterapiklinikken, APS og at formidle de mange facetter i et allianceopbyggende arbejde med en meget kontaktsvag patient. Artiklen beskriver prøveforløb og første del af et behandlingsforløb og er bygget op, således at praksisbeskrivelser fra...

  2. EU standarder for isoleringsmaterialer af cellulosefibre

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2003-01-01

    Resume af rapport om status for udarbejdelsen af EU standarder for isoleringsmateriale af cellulosefibre, udarbejdet af Landsforeningen Økologisk Byggeri under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"......Resume af rapport om status for udarbejdelsen af EU standarder for isoleringsmateriale af cellulosefibre, udarbejdet af Landsforeningen Økologisk Byggeri under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  3. Epidemiologi af spiseforstyrrelser

    DEFF Research Database (Denmark)

    Waaddegaard, Mette

    2010-01-01

    Spiseforstyrrelser som anoreksi og bulimi har op gennem det 20. århundrede og især inden for de sidste 50 år været et stigende problem i den vestlige verden. Problemet er særlig udbredt blandt unge kvinder, der står på tærsklen til voksenverdenen, og har store omkostninger af såvel psykologisk so...

  4. På sporet af sprogpsykologi

    DEFF Research Database (Denmark)

    2005-01-01

    Sprogpsykologi beskæftiger sig med, hvordan sprog og mennesker hænger sammen, og hvilke følger sammenhængen får for vore forståelser af verden og os selv. Denne antologi henvender sig til den sproginteresserede, der ønsker at gå et lag dybere end sprogets grammatiske sider. Sprog er ikke kun et l...

  5. Optisk kvantificering af gopler

    DEFF Research Database (Denmark)

    Christensen, Jens Tang

    , udført i glasfiberarmeret polyester. Lyspanelerne består af et antal kraftige lysdioder med Fresnell-linser som leverer en meget høj lysintensitet. Paravanen trækkes med lav hastighed (1 knob) i stålwirer efter et skib. Kameraet er et IQeye602 netværkskamera som leverer billeder med en opløsning på 1600...

  6. Innovation af innovation

    DEFF Research Database (Denmark)

    Harste, Gorm

    2009-01-01

    , at innovation af innovationen forsøges gennemført på en måde, hvor tiden kræves at forholde sig til sin egen tidslighed i form af fremtid, nutid, fortid og ikke mindst i form af samtidighed. I tiden skal vi iagttage, hvordan vi iagttager tiden. Vi dobbelt-koder tiden på samme måde, som forskning forsker i...... organisationssystemerne. De to typer systemer kan noget helt bestemt med fænomenet tid. De kan synkronisere. Analyseres organisationssystemer ser vi, imidlertid at innovation kræver ro. Stærkt innovative systemer er militærsystemet og kunstsystemet, der også inddrages, og hvor vi ser paradokset mellem innovation og...... involution. Tid er med et medium og ikke et lufttomt rum. Tid er end ikke en gasart, men udgør et solidt fluidum, som samfundet bader i og flyder i, konstant i bevægelse. Reformer forudsætter former, og innovation forudsætter involution. Kun sådan muliggøres evolution....

  7. Anvendelser af Pervasive Communication

    DEFF Research Database (Denmark)

    Brønsted, Jeppe

    I øjeblikket er den måde, vi kommunikerer på, ved at ændre sig drastisk. Fra at vi for få år siden var nødt til at nøjes med Internetkommunikation mellem stationære computere, forbindes en masse nye typer af enheder i dag på nye måder. Da vi nu ikke længere er bundet til en computer, der ikke kan...... flytte sig, bliver en masse nye ting mulige, fordi vi er forbundet med omverdenen i enhver kontekst. Da vi traditionelt ikke tænker i at være forbundet altid overalt er det ikke let at se, hvordan dette nye paradigme påvirker os i vores hverdag og hvordan vi kan udnytte det til nye forretnings- og...... forskningsmuligheder. For at gøre det hele lidt mere konkret, præsenteres i dette dokument en række eksempler på brug af Pervasive Communication. Udvalget af eksempler skal ikke ses som værende udtømmende, men snarere som håndplukkede eksempler der hver repræsenterer en genre. I dokumentet er både valgt...

  8. Luftforureninger ved anvendelse af alternative isoleringsmaterialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2003-01-01

    Resume af rapport om luftforureninger ved anvendelse af alternative isoleringsmaterialer, udarbejdet af Arbejdsmiljøinstituttet og Statens Byggeforskningsinstitut under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"......Resume af rapport om luftforureninger ved anvendelse af alternative isoleringsmaterialer, udarbejdet af Arbejdsmiljøinstituttet og Statens Byggeforskningsinstitut under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  9. Numerical analysis for two-dimensional compressible and two-phase flow fields of air-water in Eulerian grid framework

    International Nuclear Information System (INIS)

    Two-phase compressible flow fields of air-water are investigated numerically in the fixed Eulerian grid framework. The phase interface is captured via volume fractions of ech phase. A way to model two phase compressible flows as a single phase one is found based on an equivalent equation of states of Tait's type for a multiphase cell. The equivalent single phase field is discretized using the Roe's approximate Riemann solver. Two approaches are tried to suppress the pressure oscillation phenomena at the phase interface, a passive advection of volume fraction and a direct pressure relaxation with the compressible form of volume fraction equation. The direct pressure equalizing method suppresses pressure oscillation successfully and generates sharp discontinuities, transmitting and reflecting acoustic waves naturally at the phase interface. In discretizing the compressible form of volume fraction equation, phase interfaces are geometrically reconstructed to minimize the numerical diffusion of volume fraction and relevant variables. The motion of a projectile in a water-filled tube which is fired by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one, and several design factors affecting the projectile movement are investigated

  10. Development of a Next-Generation Membrane-Integrated Adsorption Processor for CO2 Removal and Compression for Closed-Loop Air Revitalization Systems

    Science.gov (United States)

    Mulloth, Lila; LeVan, Douglas

    2002-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane integrated, adsorption processor for CO2 removal nd compression in closed-loop air revitalization systems. This processor will use many times less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of gas dryer, CO2 separator, and CO2 compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  11. Implementation of a multi-lingual, Internet-supported benchmarking system for compressed-air installations; Umsetzung eines mehrsprachigen internetgestuetzten Benchmarking von Druckluftanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses how know-how can be improved and how optimisation activities can be stimulated in the area of compressed-air generation. The authors estimate that potential energy-savings of 20 to 40% are possible. The aim of the project - to introduce a benchmarking system already in use in Germany to the Swiss market - is discussed. This benchmarking is to help companies identify weak points in their compressed-air systems. An Internet-based information platform is introduced which was realised in 2004 and is being continually extended. The use of the benchmarking process is illustrated with a comprehensive flow-diagram and 'screen-shots' of the relevant Internet pages.

  12. The start-up of a gas turbine engine using compressed air tangentially fed onto the blades of the basic turbine

    Science.gov (United States)

    Slobodyanyuk, L. K.; Dayneko, V. I.

    1983-01-01

    The use of compressed air was suggested to increase the reliability and motor lifetime of a gas turbine engine. Experiments were carried out and the results are shown in the form of the variation in circumferential force as a function of the entry angle of the working jet onto the turbine blade. The described start-up method is recommended for use with massive rotors.

  13. Compressed-air energy-storage preliminary design and site-development program in an aquifer. Volume 7: Environmental, safety and licensing considerations

    Science.gov (United States)

    1982-12-01

    The suitability of aquifers as compressed air energy storage (CAES) sites was examined. The methodology and results of the study are described. The probability, severity, and recommended control measures for the environmental and safety impacts that could result from the construction and operation of a CAES facility are outlined. The permits and approvals that would be required and the time estimated for their acquisition are also described.

  14. Forekomst af resistente bakterier og forbrug af antibiotika til hunde

    DEFF Research Database (Denmark)

    Pedersen, Karl; Pedersen, Kristina; Jensen, Helene; Finster, Kai; Jensen, Vibeke Frøkjær; Heuer, Ole E.

    2007-01-01

    Forekomsten af antibiotikaresistens i forskellige patogene bakterier fra hunde blev bestemt og resultaterne sammenholdt med forbrug af antibiotika til hunde i Danmark. I undersøgelsen indgik isolater af Staphylococcus intermedius (n=201), Streptococcus canis (n=37), Pseudomonas aeruginosa (n=39......), Pasteurella multocida (n=25), Bordetella bronchiseptica (n=14), Proteus spp. (n=29), og E. coli (n=449). I undersøgelsen anvendtes data fra VetStat databasen. Størstedelen af de antibiotika, der bruges til hunde er bredspektrede. Penicilliner med udvidet spektrum, cephalosporiner samt sulphonamider...

  15. Evaluering af lokale udviklingsprocesser

    DEFF Research Database (Denmark)

    Jensen, Bente

    gode evalueringsmodeller, samt hvilken betydning mål og indhold har for anvendelse af en konkret evalueringsmodel. I HPA-projektet sigtes imod såvel handlingsorienteret evaluering, såkaldt selvevaluering, som virkningsevaluuering. Rapporten opstiller modeller for de forskellige evalueringstyper og......Rapporten udgør arbejdspapir nr 14 i forskningsprojektet "Handlekompetence i pædagogiske arbejde med socialt udsatte børn og unge - indsats og effekt (HPA-projektet). Rapporten diskuterer det grundlæggende spørgsmål: Hvad er evaluering? Herunder spørgsmål om hvilke dimensioner der skal medtænkes i...

  16. Om anvendelsen af Foucaults magtbegreb

    DEFF Research Database (Denmark)

    Jørgensen, Kenneth Mølbjerg

    Artiklen argumenterer for, at anvendelsen af Foucaults magtbegreb er knyttet til analysen og problematiseringen af de værdier, som forandringsprocesser i organisationer og andre sociale sammenhænge hviler på. Mere præcist argumenteres der for, at magtbegrebet er udviklet i forhold til at konfront......Artiklen argumenterer for, at anvendelsen af Foucaults magtbegreb er knyttet til analysen og problematiseringen af de værdier, som forandringsprocesser i organisationer og andre sociale sammenhænge hviler på. Mere præcist argumenteres der for, at magtbegrebet er udviklet i forhold til at...

  17. Development of a Low-Power CO2 Removal and Compression System for Closed-Loop Air Revitalization in Future Spacecraft

    Science.gov (United States)

    Mulloth, Lila M.; Rosen, Micha; Affleck, David; LeVan, M. Douglas; Moate, Joe R.

    2005-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the design and prototype development of a two-stage CO2 removal and compression system that will utilize much less power than NASA s current CO2 removal technology. This integrated system contains a Nafion membrane followed by a residual water adsorber that performs the function of the desiccant beds in the four-bed molecular sieve (4BMS) system of the International Space Station (ISS). The membrane and the water adsorber are followed by a two-stage CO2 removal and compression subsystem that satisfies the operations of the CO2 adsorbent beds of the 4BMS aid the interface compressor for the Sabatier reactor connection. The two-stage compressor will utilize the principles of temperature-swing adsorption (TSA) compression technology for CO2 removal and compression. The similarities in operation and cycle times of the CO2 removal (first stage) and compression (second stage) operations will allow thermal coupling of the processes to maximize the efficiency of the system. In addition to the low-power advantage, this processor will maintain a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of membrane gas dryer and CO2 separator and compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  18. Etablering af platform for optimering af avlsfremgange i dansk akvakultur

    DEFF Research Database (Denmark)

    Meier, Kristian; Norberg, Elise; Sørensen, Anders Christian;

    en havbrugsvirksomhed, der opdrætter og eksporterer ørreder og rogn. I forhold til de deltagende virksomheders forskellige behov har der været følgende leverancer i avlsprojektet: 1) Typeavlsplaner for havbrugsvirksomheder, 2) Etablering af basepopulation for Musholm A/S, 3) Optimering af avlsplaner...

  19. Overførsel af viden ved flytning af produktion

    DEFF Research Database (Denmark)

    Madsen, Erik Skov; Riis, Jens Ove; Wæhrens, Brian Vejrum

    2010-01-01

    Empiriske studier i tre industrielle virksomheder har afsløret, at selv virksomheder med mange års erfaring i at overføre produktion til andre lande hovedsagelig fokuserer på planlægning af den fysiske overflytning af produktionsudstyr og fokuserer på den eksplicitte viden, der er tilknyttet prod...

  20. Cycle-by-cycle Variations in a Direct Injection Hydrogen Enriched Compressed Natural Gas Engine Employing EGR at Relative Air-Fuel Ratios.

    Directory of Open Access Journals (Sweden)

    Olalekan Wasiu Saheed

    2014-07-01

    Full Text Available Since the pressure development in a combustion chamber is uniquely related to the combustion process, substantial variations in the combustion process on a cycle-by-cycle basis are occurring. To this end, an experimental study of cycle-by-cycle variation in a direct injection spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation at relative air-fuel ratios was conducted. The impacts of relative air-fuel ratios (i.e. λ = 1.0, 1.2, 1.3 and 1.4 which represent stoichiometric, moderately lean, lean and very lean mixtures respectively, hydrogen fractions and EGR rates were studied. The results showed that increasing the relative air-fuel ratio increases the COVIMEP. The behavior is more pronounced at the larger relative air-fuel ratios. More so, for a specified EGR rate; increasing the hydrogen fractions decreases the maximum COVIMEP value just as increasing in EGR rates increases the maximum COVIMEP value. (i.e. When percentage EGR rates is increased from 0% to 17% and 20% respectively. The maximum COVIMEP value increases from 6.25% to 6.56% and 8.30% respectively. Since the introduction of hydrogen gas reduces the cycle-by-cycle combustion variation in engine cylinder; thus it can be concluded that addition of hydrogen into direct injection compressed natural gas engine employing EGR at various relative air-fuel ratios is a viable approach to obtain an improved combustion quality which correspond to lower coefficient of variation in imep, (COVIMEP in a direct injection compressed natural gas engine employing EGR at relative air-fuel ratios.

  1. Simulering af dagslys i digitale modeller

    DEFF Research Database (Denmark)

    Villaume, René Domine; Ørstrup, Finn Rude

    2004-01-01

    Projektet undersøger via forskellige simuleringer af dagslys, kvaliteten af visualiseringer af komplekse lysforhold i digitale modeller i forbindelse med formidling af arkitektur via nettet. I en digital 3D model af Utzon Associates Paustians hus, simulers naturligt dagslysindfald med  forskellig...... Renderingsmetoder som: "shaded render" /  ”raytraceing” /  "Final Gather /  ”Global Illumination”...

  2. Hvordan integration af it?

    DEFF Research Database (Denmark)

    Toft, Herdis

    Fokus i artiklen er den måde, hvorpå børn positionerer sig på i skolerummet, og på, hvordan børn gennem brug af it opbygger og integrerer digital kompetence forstået som færdigheder, kundskaber og holdninger, der skal sætte dem i stand til at agere i det lærende samfund. Med udgangspunkt i et...... og genrer - eksempelvis sms, gyserfortællinger og rollespil - muliggør improvisationer og giver børnene lejlighed til at afprøve mundtlige, skriftlige, billedlige og lydlige udtryksformer på nye måder. It muliggør i denne forbindelse, ikke mindst via mediernes kobling til børnenes legekultur uden for...

  3. Dimensionering af plansiloer til ensilage

    DEFF Research Database (Denmark)

    Terpager Andersen, K.

    Der er fortsat stor interesse for bygning af plansiloer til ensilage, og SBI's afdeling for landbrugsbygninger er derfor i gang med at udarbejde et sæt byggeblade herom. For at kunne dimensionere sådanne siloer er det nødvendigt at kende størrelsen af de tryk, ensilagen udøver på silosiderne, og ...

  4. Medieret Vejledning af Problemorienteret Projektarbejde

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    2006-01-01

    Denne artikel ser nærmere på de ændrede betingelser og nye udfordringer, en vejleder af problemorienteret projektarbejde står over for i forbindelse med IKT-medieret vejledning af projektgrupper med geografisk adskilte deltagere. Artiklen anvender empiri om en vejleders situation i forhold til ve...

  5. Kvalifikation af den optiske aftastning

    DEFF Research Database (Denmark)

    Sobiecki, René

    Hvor koordinatmålemaskinen i årtier har indtaget en nøgleposition i en virksomhed til fremskaffelse af måledata, ser vi nu en udvikling i retning af mere og mere optisk måleudstyr. Profilprojektoren er vendt tilbage i en ny avanceret form. Fordele og ulemper ved mekanisk kontra optisk måling er v...

  6. Anbefalinger til organisering af uddannelserne

    DEFF Research Database (Denmark)

    Andersen, Lars; Andersen, Lars Døvling; Hornemann, Birte C.;

    2009-01-01

    Notatet sammenfatter de diskussioner, som det af fakulteterne nedsatte udvalg vedrørende nye undervisnings- og eksamensformer har haft, og de anbefalinger til en omlægning af vores uddannelsessystem, som udvalget har valgt at give. Notatet er samtidig en begyndelse på en erfaringsudveksling om ny...

  7. Seminar om evaluering af forskningsprogrammer

    DEFF Research Database (Denmark)

    Larsen, Anders Stig Skau; Pedersen, Søren Marcus

    Dette Working Paper sammenfatter indlæg og konklusioner fra et seminar om evaluering af Fødevareministeriets Forskningsprogrammer afholdt den 26. februar 2007 af Direktoratet for FødevareErhverv og Fødevareøkonomisk Institut, Københavns Universitet. På seminaret blev et nyt metodeoplæg til...

  8. Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

    Science.gov (United States)

    Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-03-01

    Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

  9. Betydningen af pesticider for forekomsten af vilde bier

    DEFF Research Database (Denmark)

    Bruus, Marianne; Dupont, Yoko Luise; Grant, Ruth;

    har spillet i nedgangen i bestøvere sammenlignet med andre aspekter af landbrugspraksis. I den nuværende regulering af sprøjtemidlerne tages specielle hensyn til honningbierne, fordi de er vigtige for bestøvningen af nogle afgrøder, og for at sikre honningproduktionen. De vilde bier er dog også...... vigtige for bestøvningen af fx kløver og mange vilde planter. Da humlebier og andre vilde bier har en anden adfærd og placerer deres reder andre steder end honningbierne, er det ikke givet, at de er beskyttet mod pesticideksponering, selv om honningbierne er. I pilotprojektet ”Betydningen af pesticider...... for forekomsten af vilde bier og honningbier” har Aarhus Universitet på to landbrugsbedrifter gennemført en indledende undersøgelse af, om humlebier udsættes for pesticider i danske landbrugsområder. Humlebistader blev sat ud i to værkstedsområder (ved Fensten og Rodstenseje syd for Odder), hvor driftsformen...

  10. Anmeldelse af World Drug Report 2005

    DEFF Research Database (Denmark)

    Møller, Kim

    Internationale udfordringer i spændingsfeltet mellem organiseret kriminalitet og narkotika. Værdien af det illegale narkotikamarked. Skabelsen af et Illicit Drug Index. Ny organisationsstruktur bag udgivelsen af denne WDR. Udgivelsesdato: December...

  11. The application of power-to-gas, pumped hydro storage and compressed air energy storage in an electricity system at different wind power penetration levels

    International Nuclear Information System (INIS)

    Many countries worldwide have committed themselves to reducing the rate in which they emit greenhouse gasses. These emissions are the major driver behind human induced global warming. Renewable electricity implementation is one way of reducing the amount of greenhouse gas emissions. However, this transition is also accompanied by some problems. The intermittency of renewables demands for a more flexible electricity system. In existing electricity systems this lack of flexibility already leads to load balancing issues increasing costs and threatening energy security. Large scale storage facilities could provide the needed flexibility. This paper focuses on the economic and environmental system consequences of the application of power-to-gas, pumped hydro storage and compressed air energy storage in an electricity system at different wind power penetration levels. The study shows that the application of large scale energy storage techniques results in economic costs reducing effects on the electricity system. These are highest for pumped hydro storage, followed by the cost reducing effects of compressed air energy storage and power-to-gas. The impact on the fuel use and the emissions is less obvious. In some scenarios, the application of storage even resulted in an increase of the fuel use and the emissions. - Highlights: • We studied the effects of adding three storage techniques to an electricity system. • We modelled: Power-to-gas, pumped hydro storage and compressed air energy storage. • Storage is used for optimizing the operational costs of the electricity system. • The economic system benefits were highest when applying pumped hydro storage. • The application of storage not always resulted in environmental system benefits

  12. Effects of intake air temperature on homogenous charge compression ignition combustion and emissions with gasoline and n-heptane

    Directory of Open Access Journals (Sweden)

    Zhang Jianyong

    2015-01-01

    Full Text Available In a port fuel injection engine, Optimized kinetic process (OKP technology is implemented to realize HCCI combustion with dual-fuel injection. The effects of intake air temperature on HCCI combustion and emissions are investigated. The results show that dual-fuel control prolongs HCCI combustion duration and improves combustion stability. Dual-fuel HCCI combustion needs lower intake air temperature than gasoline HCCI combustion, which reduces the requirements on heat management system. As intake air temperature decreases, air charge increases and maximum pressure rising rate decreases. When intake air temperature is about 55ºC, HCCI combustion becomes worse and misfire happens. In fixed dual fuel content condition, HC and CO emission decreases as intake air temperature increases. The combination of dual-fuel injection and intake air temperature control can expand operation range of HCCI combustion.

  13. Udvikling af CO2 neutralt byrumsarmatur

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Corell, Dennis Dan;

    Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt.......Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt....

  14. Afcheckning af fugtmåleceller

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2001-01-01

    Resume af rapport om fugtmåleceller til måling af fugt i isoleringsmaterialer, udarbejdet af Bygge- og Miljøteknik under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"......Resume af rapport om fugtmåleceller til måling af fugt i isoleringsmaterialer, udarbejdet af Bygge- og Miljøteknik under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  15. Intelligent styring af dynamisk LED belysning

    DEFF Research Database (Denmark)

    Thorseth, Anders; Corell, Dennis Dan; Hansen, Søren Stentoft;

    Denne slutrapport giver en kort beskrivelse af arbejdet, der er udført af DTU Fotonik i projektet ”Intelligent styring af dynamisk LED belysning” støttet af EUDP. Arbejdet er udført i perioden 2011‐2012 i samarbejde med Lighten.......Denne slutrapport giver en kort beskrivelse af arbejdet, der er udført af DTU Fotonik i projektet ”Intelligent styring af dynamisk LED belysning” støttet af EUDP. Arbejdet er udført i perioden 2011‐2012 i samarbejde med Lighten....

  16. Nyttigt bidrag til professionalisering af revisionsudvalg

    DEFF Research Database (Denmark)

    Thomsen, Steen

    2009-01-01

    Anmeldelse af: KPMG. 2009, Audit Committee Institute. Revisionsudvalg i Praksis. 2. reviderede udgave.......Anmeldelse af: KPMG. 2009, Audit Committee Institute. Revisionsudvalg i Praksis. 2. reviderede udgave....

  17. Preparatory work for the start of the Swiss Compressed-Air Efficiency campaign and accompanying work on the setting-up of a compressed air competence centre; Vorarbeiten zum Start der Kampagne Druckluft effizient Schweiz und begleitende Arbeiten zum Aufbau eines Druckluftkompetenzzentrums

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P. [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany); Stadelmann, B. [Hochschule fuer Technik und Architektur (HTA) Luzern, Horw (Switzerland)

    2004-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at how a campaign on compressed-air efficiency was prepared. Three work packages are described: The drawing-up of an implementation plan which defined the measures to be implemented by the campaign, incorporation of all relevant players in the preparation and acquisition of companies for the active realisation and co-financing of the activities, and a pilot project to optimise the compressed air supply in a chemical company. The institutions involved are introduced and the definition of the concept to be implemented is discussed. Measurement campaigns, benchmarking and publications to be made are discussed. The implementation of a pilot project at a chemicals company in Switzerland is described.

  18. AF Termination: the Holy Grail of Persistent AF Ablation?

    Directory of Open Access Journals (Sweden)

    Dennis H. Lau, MBBS

    2010-06-01

    Full Text Available The optimal catheter ablation approach for longstanding persistent atrial fibrillation (AF remains elusive despite significant advances made in our understanding of this arrhythmia. A recent systematic review highlighted the significant variation in procedural success rate both within and between techniques, necessitating repeat ablation procedures and anti-arrhythmic drugs to achieve improved outcomes in those with long-standing persistent AF.1 Indeed, current expert consensus statement recommended ablation beyond ostial pulmonary vein isolation for these patients.2 Despite incorporating various substrate modification techniques which commonly include linear lesions and targeting of complex fractionated electrograms, the reported success rates from various laboratories are still below par to those in paroxysmal AF patients.1 Perhaps the often dilated and chronically remodeled atria in longstanding persistent AF patients harbor complex structural substrates capable of maintaining the arrhythmia beyond amelioration even with extensive catheter ablation in some. Certainly, this reflects our incomplete understanding of the complex mechanisms underlying this arrhythmia.

  19. Modellering af elforbrug til netanalyse

    DEFF Research Database (Denmark)

    Østergaard, Jacob

    I denne rapport undersøges mulighederne for at etablere en model for elforbruget, der kan anvendes ved analyser af det østdanske transmissionsnet. Rapporten henvender sig til ingeniører og beslutningstagere, der ønsker viden om betydningen af en nøjagtig elforbrugsmodel og om mulighederne for i p...... simuleringsresultater med mindre usikkerhed, og der opnås en integration mellem eksisterende systemer, idet data fra en række systemer bl.a. Panda, elforbrugsprognoser, elforbrugspaneler og stationsprognoser kan udnyttes til etableringen af en model....

  20. Estimering af afløbskoefficienter ved brug af vejrradarer

    DEFF Research Database (Denmark)

    Ahm, Malte

    2013-01-01

    Korrekt bestemmelsen af et oplands afløbskoefficienter er essentielt i forbindelse med afløbsteknisk modellering. Specielt i forbindelse med realtidsstyring, da afløbskoefficienterne er styrende for afløbssystemets massebalance. Dette studie viser en effektiv metode til at estimere de hydrologiske...... parametre på deloplandsniveau på baggrund af afstrømningsmålinger for hele oplandet kombineret med vejrradar data....

  1. Effektivisering af forbelastning ved anvendelse af vertikaldræn

    DEFF Research Database (Denmark)

    Jensen, B. S.; Sørensen, Carsten S.

    2000-01-01

    delelementer af vejen, udføres vejen ved forbelastning. Sætninger fra traditionel konsolidering af forbelastning vil tage 30 år. Da denne periode skal reduceres til 20 måneder, vælges at etablere vertikal dræn gennem forbelastningsdæmningen. Herved reduceres drænvejen fra 6,O m til 0,5 m og drænretningen...

  2. Revisors opklaring af besvigelser - Læren af praksis

    DEFF Research Database (Denmark)

    Bloch Christensen, Maria; Kristensen, Rikke Holmslykke; Warming-Rasmussen, Bent

    Besvigelser i form af misbrug af aktiver eller regnskabsmanipulation er et fænomen, som desværre forekommer jævnligt både i Danmark og i udlandet. Fænomenet har derfor stor relevans og bevågenhed blandt danske selskabers stakeholdere. Når skaden er sket, handler diskussionen typisk om...... virkede så tillidsvækkende, og at besvigelsen var udført meget snedigt, så ingen havde fattet mistanke! Netop adresseringen af dette er motivationen til denne bog. Bogens første del beskæftiger sig således med analysen af personen bag besvigelsen og dennes beslutningsproces. Analysen lægger op til et nyt...... arbejdspapir med optegnelser af ledende medarbejderes ansvarsområder og observationer af deres aktuelle situation. Bogens anden del analyserer en række besvigelsessager fra praksis og giver eksempler på revisionshandlinger, som ville have opdaget besvigelsen. Der lægges op til endnu et arbejdspapir, som samler...

  3. Dokumentation af konvertering af trafiktal til emissionsopgørelser

    DEFF Research Database (Denmark)

    Kveiborg, Ole; Jensen, Thomas Christian

    2009-01-01

    Danmarks Miljøundersøgelser (DMU) er ansvarlig for at opgøre og rapportere danske drivhusgas-emissioner til Klimakonventionen, Geneve-konventionen og EU’s overvågningsmekanisme for driv-husgasser. Til brug for opgørelser af emissioner fra transportområdet har DMU behov for en række oplysninger fra...... Transportministeriet. Vejdirektoratet (VD) har hidtil stået for levering af disse oplysnin-ger. DMU skal nu som følge af Danmarks og EU’s ratificering af Kyoto-protokollen dokumentere, at der er foretaget de nødvendige foranstaltninger for at sikre de årlige opgørelser. Derfor ønskes nu en mere formaliseret aftale...... vedrørende levering af oplysninger for transportområdet. Dette notat sammenfatter de konverteringsrutiner og metoder, der er anvendt for at beregne bestan-den af køretøjer, deres trafikarbejde, hastigheder, last mv....

  4. AA-CAES. Opportunities and challenges of advanced adiabatic compressed-air energy storage technology as a balancing tool in interconnected grids

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt, Roland; Moser, Peter [RWE Power AG, Essen (Germany). Forschung und Entwicklung, Neue Technologien; Hoffmann, Stephanie [GE Global Research Europe, Garching (Germany); Pazzi, Simone [GE Infrastructure, Oil and Gas, Firenze (Italy); Klafki, Michael [ESK GmbH (RWE Group), Freiberg (Germany); Zunft, Stefan [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Stuttgart (Germany). Inst. fuer Technische Thermodynamik

    2008-07-01

    An expansion of CO{sub 2}-neutral energy supply is in the focus of European and national environmental policy and will be crucially supported by offshore wind power generation in future. Grid-compatible integration of these fluctuating electricity quantities will - in the medium term already - require substantial adjustments of the German grid and power plant system in order to cope with the upcoming new boundary conditions. The development of new technologies for large-scale electricity storage is a key element in future flexible European electricity transmission systems. Electricity storage in Adiabatic CAES power plants offers the prospect of making a substantial contribution to reach this goal. This concept allows efficient, local zero-emission electricity storage on the basis of compressed air in underground caverns. The compression and expansion of air in turbomachinery help to balance power generation peaks that are not demand-driven on the one hand and consumption-induced load peaks on the other. Before this concept can be implemented, however, several technical problems must be solved and technical development work done, especially in the field of turbomachinery and the required heat storage device. This paper outlines the technical possibilities and the need for development. Ongoing development activities are described and first interim results presented. (orig.)

  5. Nyt planetsystem opdaget af Kepler

    DEFF Research Database (Denmark)

    Buchhave, Lars C. Astrup

    2010-01-01

    Ved hjælp af NASA-satellitten Kepler har astronomerne fundet to planeter, der kredser om en fjern stjerne. Der er muligvis også en tredje planet, der ikke er meget større end Jorden......Ved hjælp af NASA-satellitten Kepler har astronomerne fundet to planeter, der kredser om en fjern stjerne. Der er muligvis også en tredje planet, der ikke er meget større end Jorden...

  6. Identificering af teknologi gennem narrativer

    OpenAIRE

    Stoustrup, Sune Wiingaard; Rising, Carl Johan; Petersen, Mikael

    2011-01-01

    Denne rapport arbejder med en gennemgang af den såkaldte 3D printer teknologi. Denne vil sættes i sammenhæng med et teknologifilosofisk ’form of life ́ forståelse fremsat af Langdon Winner, samt en metode til at udrede det komplekse forhold: menneske-teknologi, med aktør-netværk teori som værktøj.

  7. En beskrivelse af tidligere stofmisbrugere

    DEFF Research Database (Denmark)

    Hecksher, Dorte

    2004-01-01

    Artiklen fokuserer på en del af et sample fra en større opfølgningsundersøgelse af døgnbehandlingsindsatsen overfor stofmisbrugere i Danmark. Formålet med artiklen er at beskrive den stoffri gruppe forud for indskrivning i døgnbehandling og i de første to år efter udskrivning fra døgnbehandling. ...

  8. Dimensionering af rørisolering

    DEFF Research Database (Denmark)

    Olufsen, P.

    Meddelelsen gennemgår metoderne til dimensionering af termisk isolering af tekniske installationer i bygninger med hovedvægten på isolering af rør og beholdere i varme- og brugsvandsanlæg. Grundlaget for opstilling af mindstekrav til rørisolering diskuteres og der sammenlignes med tilsvarende...

  9. Professor: Lær af Canada

    DEFF Research Database (Denmark)

    Greve, Carsten

    2013-01-01

    Transportdebatten: En mulig finansiering af fremtidige infrastrukturprojekter kunne være OPP. Danmark bør tage ved lære af erfaringer fra Canada.......Transportdebatten: En mulig finansiering af fremtidige infrastrukturprojekter kunne være OPP. Danmark bør tage ved lære af erfaringer fra Canada....

  10. Bilag til forskningsoversigt - Effekterne af Cooperative Learning

    DEFF Research Database (Denmark)

    Larsen, Lea Lund

    Ved en opsamling af de empiriske studier vedrørende effekten af CL inden for voksenundervisningsfeltet ses en overvægt af studier, som rapporterer en positiv effekt af CL i forhold til de voksne lærendes faglige udbytte. En meta-analyse over 168 amerikanske undersøgelser på universitetsniveau vis...

  11. Kants Kritik af dømmekraften

    DEFF Research Database (Denmark)

    Introduktion til Kants Kritik af dømmekraften bestående af otte artikler, der følger værkets egen tematiske opbygning......Introduktion til Kants Kritik af dømmekraften bestående af otte artikler, der følger værkets egen tematiske opbygning...

  12. På sporet af de gyldne opskrifter?

    DEFF Research Database (Denmark)

    Poulfelt, Flemming

    2015-01-01

    Børsen Ledelse. Markedet for kogebøger er stort. For der produceres hvert år et hav nye af slagsen. Nogle udgives af kendte kokke, nogle af særlige eksperter inden for kost og motion, og andre af personer, der har en ægte interesse inden for gastronomi og mad. På ledelsesområdet findes en...

  13. Vi lever i en verden af ting

    DEFF Research Database (Denmark)

    Helms, Niels Henrik

    2009-01-01

    Vi lever i en verden af ting Vi lever i en verden af ting. Menneskeligt frembragte påvirkninger, konstruktioner og manipulationer af vores natur, hvis det da er vores natur. Vi lever også i et særligt innovations-regime, hvor vi bliver vurderet på og defineret af, hvad og hvordan vi kan bidrage med...

  14. Behandling af historiske data for hele Limfjorden

    DEFF Research Database (Denmark)

    Henriksen, Peter

    2008-01-01

    forekomst af PSP-toksinproducerende alger, har projektet bl.a. vist, at der er forskel på ophobning af algetoksiner i muslinger afhængigt af om de vokser på et lineopdrætsanlæg eller som bundmuslinger. Endvidere er der blevet identificeret en række mulige tilpasninger af prøvetagningsprogrammerne, som kan...

  15. Demokratiseringen af den politiske diskurs i Polen

    DEFF Research Database (Denmark)

    Arnfast, Juni Søderberg

    1999-01-01

    Gennem en analyse af brugen af personlige pronominer i politiske tekster fra udvalgte, polske medier diskuteres forandringerne i den polske, politiske diskurs gennem 1980'erne. Det påvises at det kommunistiske styres anvendelse af pronominet 'vi' skifter konnotationer i retning af en mindre ideol...

  16. Optimering af slutrensning på jorddambrug

    DEFF Research Database (Denmark)

    Grønborg, Ole; Frier, Jens-Ole

    betydeligt skridt fremad indenfor de afdækkede nøgleområder. Nærværende rapport er resultatet af fase 1 og beskæftiger sig derfor med afdækning af den tilgængelige viden indenfor området, vurdering af denne viden og udpegning af den vidensmangel, der er særlig vigtig for implementering af den optimale...

  17. Optimal management of compressed air energy storage in a hybrid wind-pneumatic-diesel system for remote area's power generation

    International Nuclear Information System (INIS)

    Electricity in Canadian remote areas is, historically, produced using Diesel generators. Its total production cost is very high not only due to inherent cost of fuel but also due to transportation and maintenance costs. Moreover, the use of fossil fuels is a significant source of greenhouse gas emissions. Hybrid systems that combine wind turbines and diesel generators reduce fuel consumption, operational cost and pollution. Adding a storage element to this hybrid system increases the penetration level of renewable sources, i.e. the percentage of renewable energy in the overall production, and further improves fuel savings. Among all energy storage techniques, CAES (compressed air energy storage) has several advantages to be combined with hybrid WDS (wind-diesel systems), due to its low cost, high power density and reliability. In a previous work, we have exposed and have evaluated a new technique to transform the existing Diesel engine to a HPCE (hybrid pneumatic combustion engine), able to operate as a bi-source engine (compressed air and fuel). Based on ideal cycle modeling, we provided a first estimation of the annual fuel economy obtained with this multi-hybrid system (WDS–HPCE). As a continuity to this work, we will compare, in this article, several strategies of management of the CAES. We will demonstrate that one of these strategies that uses an algorithm based on wind speed forecast, is the most efficient. We will, also, provide an evaluation of the fuel economy generated by the WDS–HPCE, as a function of the wind power penetration ratio, the air-storage capacity, and the average wind speed on site. - Highlights: • We model thermodynamic cycle of a new hybrid pneumatic combustion engine. • we evaluate all ratios of pneumatic power to fuel power and select two highlighted. • we calculate maps of fuel and air consumption for the highlighted strategies. • We evaluate fuel consumption for each strategy and for a combination between both. • we get

  18. Compressed air energy storage power plants as an option for the grid integration of renewable energy sources. A comparison of the concepts; Druckluftspeicherkraftwerke als Option zur Netzintegration erneuerbarer Energiequellen. Ein Vergleich der Konzepte

    Energy Technology Data Exchange (ETDEWEB)

    Tuschy, Ilja [Fachhochschule Flensburg (Germany). Inst. fuer Energiesystemtechnik

    2008-07-01

    The integration of an increasing amount of power generation from renewable energy sources is a large challenge for the electricity supply. Apart from the compensation of varying production by supra-regional grids and apart from the further development of peak load power stations the energy storage is discussed as an option. Several power suppliers referred to compressed air energy storage plants as a possible solution. The authors of the contribution under consideration compare the different concepts for compressed air energy power stations systematically. A special emphasis is the thermodynamic evaluation of the different concepts. Also energy-technical aspects are addressed which decide on possibilities of application and perspectives of development for compressed air energy power stations.

  19. AF Termination: the Holy Grail of Persistent AF Ablation?

    Directory of Open Access Journals (Sweden)

    Dennis H. Lau

    2010-05-01

    Full Text Available The optimal catheter ablation approach for long-standing persistent atrial fibrillation (AF remains elusive despite significant advances made in our understanding of this arrhythmia. A recent systematic review highlighted the significant variation in procedural success rate both within and between techniques, necessitating repeat ablation procedures and anti-arrhythmic drugs to achieve improved outcomes in those with long-standing persistent AF . Indeed, current expert consensus statement recommended ablation beyond ostial pulmonary vein isolation for these patients . Despite incorporating various substrate modification techniques which commonly include linear lesions and targeting of complex fractionated electrograms, the reported success rates from various laboratories are still below par to those in paroxysmal AF patients.

  20. Risikovurdering af lossepladsers påvirkning af overfladevand

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Sonne, Anne Thobo; Tuxen, Nina;

    afgørende betydning for hvilken påvirkning af overfladevand, de kan have. Projektet viser, at det er muligt at opstille i alt 6 typologier for lossepladserne. Forureningsstofferne som findes i lossepladser, og som kan true overfladevand er opdelt i 3 grupper: ”klassiske” perkolatparametre, miljøfremmede...... organiske stoffer samt tungmetaller. I forhold til truslen mod overfladevand er forekomsten af organisk stof, ammonium og jern fundet særligt interessante, i det de alle er potentielt iltforbrugende ved udsivning til overfladevand. Ammonium, jern, en række tungmetaller samt specifikke miljøfremmede stoffer...... har også en toksisk effekt, som er afspejlet i stoffes miljøkvalitetskrav. Forureningsstoffernes transportveje fra en losseplads mod overfladevand afhænger af lossepladsens typologi. Der er identificeret i alt 4 betydende transportveje fra en losseplads via grundvand til overfladevand: Umættet...

  1. Ledelsesroller i globalisering af cleantech

    DEFF Research Database (Denmark)

    Knudsen, Poul Frøjk; Tambo, Torben

    2011-01-01

    Cleantech anses i de fleste industrialiserede lande for den nye vækstbølge, der både skal fastholde arbejdspladser og beskæftigelse og også redde miljøet. Danmark har været early-mover på vindkraft. Aktiv ledelse har til dato fastholdt et forspring. Denne aktive ledelse har sikret anvendelse af...... nyeste teknologier, globalisering af salg, installation og produktion, og at vækstdagsordenen er blevet fastholdt. Den globale satsning på cleantech sætter disse ledelsesmæssige kvaliteter under pres. Dette studie ser på en mellemstor komponentleverandør til vindindustrien, og dennes kamp for...... økonomisk bæredygtighed præger ledelsesprocesserne. Studiet giver et sæt anbefalinger til en justering af egen-forståelsen i den bredere del af cleantech-sektoren med fokus på ledelse, som i denne sektor i særlig grad skal håndtere krav ud over den klassiske supply chain i form af politiske dagsordener i...

  2. Brug af alternativ isolering i forbindelse med renovering af ældre etageejendomme

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2003-01-01

    Resume af rapport om praktiske erfaringer med brug af alternative isoleringsmaterialer i en renoveringsopgave, udarbejdet af Byfornyelse København m.fl. under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  3. Implementering af drift i byggeri

    DEFF Research Database (Denmark)

    Damgaard, Torben; Erichsen, Pia Bruun

    med i byggeriet. Som følge af dette skal der løbende skabes nye relationer mellem parterne, og der skal arbejdes sammen på nye måder. De forskellige barrierer syntes at være mest fremtrædende ved offentlige byggerier, men også private innovative byggerier er præget af barriererne. Der er flere....... Løsningsforslagene kan næppe gennemføres og vise effekt med det samme, men flere af dem vil kunne sættes i gang på relativt kort sigt. Rapporten undlader at behandle spørgsmålet om, hvor meget driftsovervejelser skal dominere i forhold til æstetiske og arkitektoniske hensyn. Den har således alene til hensigt at få...

  4. Rapportering af diagnostiske undersøgelser af faldvildt 2014

    DEFF Research Database (Denmark)

    Chriél, Mariann; Hansen, Mette Sif; Larsen, Gitte;

    i grævling for første gang i denne epidemi. Der modtaget mange rådyr til undersøgelse, der giver et godt kendskab til de problemer der ses i bestanden. Der er fortsat mange rådyr med dårlige tænder og deraf følgende ringe kondition på grund af mange gamle dyr i bestandene. Der blev gennemført en...... undersøgelse af snabelklove hos rådyr, da denne tilstand ses relativt hyppigt. Materialet er indsamlet over flere år, og afslørede at mange klovben er drejede. En lignende tilstand kendes fra heste og kvæg efter pludselige foderskift eller fodring med for store mængder energi og resulterer i snabelklove....../-hove. Det hyppige fund af drejede klovben hos rådyr kunne tyde i samme retning. I 2014 fandt det første udbrud af influenza A virus blandt spættede sæler sted i Europa. Dette udbrud centrerede sig omkring Danmark og resulterede i stor dødelighed blandt sælerne pga. samtidig bakteriel lungebetændelse...

  5. Cold Climate Field Test Analysis of an Air-Source Heat Pump with Two-Stage Compression and Economizing

    OpenAIRE

    Caskey, Stephen Lance

    2013-01-01

    A Department of Defense project was established to conduct a field demonstration led by Purdue University with several industry partners. The technology investigated was an air-source, two-stage heat pump with closed-loop economizing. The field demonstration site was a military barracks on a National Guard base, Camp Atterbury, in southern Indiana. Two heat pumps were built at the Ray W. Herrick Laboratories and installed into two almost identical, barracks buildings. Data on the heat pump op...

  6. Simulation of an Air-Source Heat Pump with Two-Stage Compression and Economizing for Cold Climates

    OpenAIRE

    Caskey, Stephen L.; Kultgen, Derek; Eckhard A. Groll; Hutzel, William; Menzi, Tobias

    2012-01-01

    A new air-source heat pump technology optimized for cold climates was designed and fabricated by the authors in close cooperation with three industrial partners. The constructed unit will undergo a field demonstration in a military barrack to identify heat pumps as cost effective systems that have less primary energy consumption when compared to traditional cold climate heating methods. A simulation model developed in EES predicted the designed heat pump performance at different ambient condi...

  7. Spectral broadening and temporal compression of 100 fs pulses in air-filled hollow core capillary fibers,

    OpenAIRE

    C. Li; Rishad, K.P.M.; Horak, P.; Matsuura, Y.; Faccio, D

    2014-01-01

    We experimentally study the spectral broadening of intense, ~100 femtosecond laser pulses at 785 nm coupled into different kinds of hollow core capillary fibers, all filled with air at ambient pressure. Differently from observations in other gases, the spectra are broadened with a strong red-shift due to highly efficient intrapulse Raman scattering. Numerical simulations show that such spectra can be explained only by increasing the Raman fraction of the third order nonlinearity close to 100%...

  8. Fluctuations of the Solitary Bubble at the Separation from the Air Cavity, Compressed by the Magnetic Field in Magnetic Liquid

    Directory of Open Access Journals (Sweden)

    M.L. Boev

    2013-12-01

    Full Text Available In the article, on the basis of the concept of "display" of geometry of a free surface of the "low-magnetic" environment by the topography of isolines of the module of intensity of a magnetic field, it is studied a form of a free surface of magnetic fluid in a static condition at the initial stage of rapprochement of a ring magnet with a surface of a column of magnetic fluid in a tube and at a stage of pressing of a cavity to a bottom. It is shown that the separation of bubbles from an air cavity occurs in close proximity to the plane of symmetry of a ring magnet on its axis. It is described the method and experimental installation for studying the possibility of electromagnetic indication of sizes of the air bubbles, being in magnetic fluid. It is discussed the results of experimental research on process of a separation of solitary air bubble from a cavity, contained in magnetic fluid and squeezed by ponderomotive forces of a magnetic field which are of interest for creation of essentially new technique of the dosed supply of small amount of gas in the reactor.

  9. På sporet af fremtidens konkurrenceevne

    DEFF Research Database (Denmark)

    Boje Rasmussen, Martin Møller

    2013-01-01

    Michael Porter og Harvard Business School står bag nyt banebrydende initiativ, Social Progress Index, som måler et samfunds evne til at skabe livskvalitet for borgerne. Dette aktualiserer debatten om udviklingen af helt nye konkurrencemodeller. Der er tale om et valg mellem tre forskellige typer...

  10. Opkomsten af den ansvarstagende familie

    DEFF Research Database (Denmark)

    Mehlsen, Camilla

    Engang gik grænsen mellem skole og hjem ved skolens port. I dag outsourcer skolen stadigt mere ansvar til forældre. Er det godt for skolen, eller trækker det handlekraften ud af lærerne? Og hvor går grænsen for, hvad forældrene skal blande sig i?...

  11. Bliver seksualitetsforskningen lykkelig af moralismeanklager?

    DEFF Research Database (Denmark)

    Frederiksen, Maja Bissenbakker

    2010-01-01

    Anmeldelse: ‘Piger bliver ikke lykkelige af analsex’ er underholdende og sine steder forstemmende læsning om de problematiske måder, hvorpå offentlige debatter de seneste år har gjort seksualitet til genstand for en overvældende bekymring og deraf følgende krav om regulering og kontrol"...

  12. Virksomhedernes opfattelse af arbejdsmarkedets "restgrupper"

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt

    2010-01-01

    er baseret på besvarelser fra 1775 private danske arbejdsgivere i 2006. Artiklen dokumenterer, at i en situation med højkonjunktur er specielt lang forudgående ledighed et meget dårligt signal at sende til arbejdsgiverne. Artiklen dokumenterer også, at erfaring med ansættelse af ældre og indvandrere...

  13. Fluoridering af drikkevandet i Danmark?

    DEFF Research Database (Denmark)

    Arvin, Erik; Spliid, Henrik; Bruvo, M.; Bardow, A.; Ekstrand, K.

    2010-01-01

    Første gang sammenhængen mellem caries (huller i tænderne) og fluoridindholdet i drikkevand blev diskuteret i vandværkskredse i Danmark var ved årsmødet i 1958. Her blev det oplyst, at fluorid i drikkevand beskytter mod caries, men man konstaterede også, at der nok ikke var stemning for fluorid......-tilsætning til drikkevandet (fluoridering). Siden da er emnet ikke taget op. Formålet med dette indlæg er at besvare spørgsmålene: 1. Er der behov for fluoridering af drikkevandet i Danmark? 2. Er der alternativer? Hvordan påvirker blødgøring af vand og andre vandbehandlingsmetoder dental caries hos børn og unge......? Som baggrund herfor vil vi redegøre for resultaterne af et netop afsluttet studium af sammenhængen mellem caries og drikkevandets sammensætning, specielt m.h.t. luoridindholdet og vandets calciumindhold (hårdhed). Undersøgelsen bekræfter, at fluorid i drikkevand i væsentlig grad beskytter mod caries...

  14. Digitalisering af det eksisterende byggeri

    DEFF Research Database (Denmark)

    Sørensen, Nils Lykke; Øien, Turid Borgestrand

    2010-01-01

    Digitalisering af det eksisterende byggeri er en vanskelig og uendelig opgave. Det giver kun mening at digitalisere eksisterende byggeri, når man har et konkret behov, og da kun at indhente og lagre de informationer, som man strategisk eller konkret har behov for. Erhvervs og Byggestyrelsen har i...

  15. Modernisering af de danske selskabslove

    DEFF Research Database (Denmark)

    Andersen, Paul Krüger; Neville, Mette; Sørensen, Karsten Engsig

    2003-01-01

    Artiklen gennemgår de ændringer i aktie- og anpartsselskabslovens som blev gennemført i foråret 2003, og som blandt andet tillader en øget brug af IT i forbindelse med generalforsamlinger samt selskabets kommunikation med aktionærerne....

  16. Domesticeringen af Ford i Danmark

    DEFF Research Database (Denmark)

    Wagner, Michael

    2011-01-01

    Det amerikanske automobilfirma Ford Motor Company (1903) med hovedkvarter i Detroit begyndte at drive forretning i Danmark omkring 1906. Dermed havde Ford tidligt fået et stærkt fodfæste i Nordeuropa, som udviklingen i salget af Ford automobiler de næste årtier til fulde skulle demonstrere...

  17. Evaluering af ICDP i praksis

    DEFF Research Database (Denmark)

    Miller, Tanja

    2015-01-01

    skridt – noget ingen tidligere har kunnet gøre” (interview faglig udvikler) ICDP programmet anvender video og billeder i arbejdet med otte samspilstemaer og syv sensitiveringsprincipper. Familiebehandlerne har ændret pædagogisk praksis i arbejdet med styrkelse af udfordrede forældres forældrekompetencer...

  18. Patentering af det humane genom

    DEFF Research Database (Denmark)

    Sommer, Tine

    2004-01-01

    Direktiv 98/44/EF om retlig beskyttelse af bioteknologiske opfindelser blev gennemført i dansk ret med ikrafttrædelse den 30. juli 2000. Direktivet indeholder i artikel 5 en central bestemmelse som giver adgang til patent på humane gener. I artikel 5, stk. 3, er indføjet et skærpet krav til...

  19. Atrial Fibrillation (AF or AFib)

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Atrial Fibrillation (AF or AFib) Updated:Feb 10,2016 What ... to the Terms and Conditions and Privacy Policy Atrial Fibrillation • Introduction • What is Atrial Fibrillation? • Why AFib Matters • ...

  20. Fluctuations of the Solitary Bubble at the Separation from the Air Cavity, Compressed by the Magnetic Field in Magnetic Liquid

    OpenAIRE

    M.L. Boev; Polunin, V.M.; O.V. Lobova; Shabanova, I.A.; L.M. Chervjakov; A.N. Ryapolov

    2013-01-01

    In the article, on the basis of the concept of "display" of geometry of a free surface of the "low-magnetic" environment by the topography of isolines of the module of intensity of a magnetic field, it is studied a form of a free surface of magnetic fluid in a static condition at the initial stage of rapprochement of a ring magnet with a surface of a column of magnetic fluid in a tube and at a stage of pressing of a cavity to a bottom. It is shown that the separation of bubbles from an air ca...

  1. Compressed air energy storage: preliminary design and site development program in an aquifer. Final draft, Task 2: Volume 2 of 3. Characterize and explore potential sites and prepare research and development plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-01

    The characteristics of sites in Indiana and Illinois which are being investigated as potential sites for compressed air energy storage power plants are documented. These characteristics include geological considerations, economic factors, and environmental considerations. Extensive data are presented for 14 specific sites and a relative rating on the desirability of each site is derived. (LCL)

  2. Experimental Study of Ambient Air Temperature Effects on The Performance of a General Vapor-Compression Refrigeration Cycle

    Directory of Open Access Journals (Sweden)

    Ayad T. Mustafa

    2013-05-01

    Full Text Available         In this work an experimental study for the vapor – compression refrigeration cycle has been performed under temperature range of  9.7-32°C. The effect of      varying temperature on heat exchangers pressures, cooling capacity, net power consumption, and coefficient of performance COP are studied .                                   The results indicated that condenser pressure, evaporator pressure, and power consumption increased with the increase of temperature. The data also indicated that cooling capacity increased as temperature increased until 15.6°C then after it decreased with further temperature increase. Also COP follow the same tread of cooling capacity.                                                                                                              

  3. Udviklingen af rumopfattelsen 1600-2000

    DEFF Research Database (Denmark)

    Brock, Steen

    Hovedtræk af rumopfattelsens idehistorie fra Descartes til Wittgenstein med speciel vægt på Kant, værkbegrebet, modelbegrebet og den fænomenologiske opfattelse af rummet som handlingens sted......Hovedtræk af rumopfattelsens idehistorie fra Descartes til Wittgenstein med speciel vægt på Kant, værkbegrebet, modelbegrebet og den fænomenologiske opfattelse af rummet som handlingens sted...

  4. Test af studerendes begrebsforståelse

    Directory of Open Access Journals (Sweden)

    Simon Olling Rebsdorf

    2006-03-01

    Full Text Available Denne oversigtsartikel præsenterer aspekter af den såkaldte Force Concept Inventory test til måling af studerendes begrebsforståelse i introducerende fysikkurser. Artiklen beskriver testens rationale, giver et overblik over testens fremkomst og præsenterer de konklusioner, uddannelsesforskere har draget af testens interessante resultater samt forskellige kritikpunkter aftesten. Endelig inddrages en kvalitativ diskussion af testens anvendelse i en dansk universitetspædagogisk sammenhæng.

  5. Kortlægning af unge

    DEFF Research Database (Denmark)

    Skou, Carl Verner

    2009-01-01

    Computerprogram til Windows XP/Vista platformen til indberetning af unge under 18 år til registering af stofmisbrug og sociale data. Udgave: 1.0.1.1 Udgivelsesdato: 01-01-2009......Computerprogram til Windows XP/Vista platformen til indberetning af unge under 18 år til registering af stofmisbrug og sociale data. Udgave: 1.0.1.1 Udgivelsesdato: 01-01-2009...

  6. Fekvensomformerbaseret design af hydraulikenhed til laboratorie

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg; Schroll, Esbjørn

    Konceptuelt design af en ferkvensomformerbaseret hyraulisk power supply til IKS. Sammenligning af traditionelt pumpedesign med varaiabelt deplacement og en konstant-pump drevet af en AC-motor med frekvensomformer. Frekvensomformer-løsningen er et interressant alternativ for fremtidige power supply's....

  7. Registrering og Benchmarking af Modus 2 Forskning

    DEFF Research Database (Denmark)

    Duus, Henrik Johannsen; Jørgensen, Jens E.

    2004-01-01

    Fremvæksten af modus 2 forskning stiller krav om en revurdering af højere læreanstalters evaluerings- og meriteringspraksis. Den endimensionale prioritering af modus 1 forskning såvel som dennes ligeså endimensionale evaluering via publikationer må afvises som utidssvarende. Som en konsekvens her...

  8. Hærdeteknologi og Holdbarhed af Betonkonstruktioner

    DEFF Research Database (Denmark)

    Sørensen, Eigil V.

    Kurset Hærdeteknologi og Holdbarhed af Betonkonstruktioner afholdes i 1. og 2. periode af forårssemesteret 2006. Kurset sigter på at give de studerende en grundlæggende forståelse af, hvorledes man designer og udfører holdbare betonkonstruktioner....

  9. Kvægbedriften - udledning af drivhusgasser

    DEFF Research Database (Denmark)

    Kristensen, Troels; Mogensen, Lisbeth

    2011-01-01

    Med et klimaregnskab for kvægbedriften får driftslederen et grundlag for at vurdere bedriftens status og muligheder for at nedbringe udledningen af drivhusgasser. I klimaregnskabet er den enkelte bedrifts årlige udledningen af klimagasser fra produktion og forbrug af foder, gødning og andre drift...

  10. Registrering af biometriske og biologiske personoplysninger

    DEFF Research Database (Denmark)

    Blume, Peter Erik; Herrmann, Janne Rothmar

    2009-01-01

    Med udgangspunkt i menneskeretsdomstolens Marper dom drøftes i artiklen indretningen af dansk rets regler om registrering af fingeraftryk og dna-profil med tilhørende biologisk materiale, og om dommen nødvendiggør ændringer af disse regler....

  11. Omlægning af bilafgifter

    DEFF Research Database (Denmark)

    Jespersen, Per Homann

    Bilafgifterne i Danmark er høje set i en international sammenligning. Beskatningen har imidlertid vægt på anskaffelse af bil, mens eksternaliteterne hovedsagelig er knyttet til anvendelsen af bilen. I artiklen analyseres mulighederne for og konsekvenserne af en afgiftsomlægning inden for et 'skat...

  12. Renovering af radiatoranlæg

    DEFF Research Database (Denmark)

    Christiansen, J.

    Rapporten beskriver fremgangsmåden ved en renovering, der omfattede udskiftning af dårligt fungerende komponenter og indregulering. Der redegøres for den komfortforbedring og de energibesparelser, der blev opnået og der gives anvisning på beregning af fremløbstemperatur og brug af kurveskiver for...

  13. Fermentering af korn øger fordøjeligheden af næringsstoffer

    DEFF Research Database (Denmark)

    Pedersen, Anni Øyan; Jørgensen, Henry; Bach Knudsen, Knud Erik; Canibe, Nuria; Poulsen, Hanne Damgaard

    Et fordøjelighedsforsøg har vist, at energiværdien af byg og hvede steg ved fermentering. Effekten var størst ved fermentering af byg, hvor fordøjeligheden af organisk stof for enden af tyndtarmen steg statistisk sikkert med 9 %. Ved fermentering af hvede steg fordøjeligheden af organisk stof...... statistisk sikkert med 3 %. Stigningen i energiværdien ved fermentering af korn kunne ikke vises ved foderanalyser (FEsv), hvilket viser, at in vitro-analyserne EFOS og EFOSi ikke kan anvendes til vurdering af effekten af fermentering. Fordøjeligheden af fosfor i foderblandinger baseret på byg eller hvede og...... tilskudsfoder steg statistisk sikkert ved fermentering af kornet. Der blev ikke tilsat mikrobiel fytase. Ved fermentering af byg steg fordøjeligheden af fosfor i foderblandingen fra 32 til 47 %, og ved fermentering af hvede steg fordøjeligheden af fosfor i blandingen fra 43 til 57 %. Fordøjeligheden af fosfor i...

  14. Fermentering af korn øger fordøjeligheden af næringsstoffer

    DEFF Research Database (Denmark)

    Pedersen, Anni Øyan; Jørgensen, Henry Johs. Høgh; Knudsen, Knud Erik Bach;

    2010-01-01

    Et fordøjelighedsforsøg har vist, at energiværdien af byg og hvede steg ved fermentering. Effekten var størst ved fermentering af byg, hvor fordøjeligheden af organisk stof for enden af tyndtarmen steg statistisk sikkert med 9 %. Ved fermentering af hvede steg fordøjeligheden af organisk stof...... statistisk sikkert med 3 %. Stigningen i energiværdien ved fermentering af korn kunne ikke vises ved foderanalyser (FEsv), hvilket viser, at in vitro-analyserne EFOS og EFOSi ikke kan anvendes til vurdering af effekten af fermentering. Fordøjeligheden af fosfor i foderblandinger baseret på byg eller hvede og...... tilskudsfoder steg statistisk sikkert ved fermentering af kornet. Der blev ikke tilsat mikrobiel fytase. Ved fermentering af byg steg fordøjeligheden af fosfor i foderblandingen fra 32 til 47 %, og ved fermentering af hvede steg fordøjeligheden af fosfor i blandingen fra 43 til 57 %. Fordøjeligheden af fosfor i...

  15. A two-dimensional, transient, compressible isothermal and two-phase model for the air-side electrode of PEM fuel cells

    International Nuclear Information System (INIS)

    A two-dimensional, transient, compressible, isothermal and two-phase flow of reactant-product mixture in the air-side electrode of proton exchange membrane fuel cells (PEMFC) are numerically studied in the present paper. The mixture is composed of four species: oxygen, nitrogen, liquid water and water vapor. The governing PDE's are conservation of the water vapor and oxygen species, momentum equation of the mixture (gas+liquid), mass conservation of the liquid phase, and mass conservation of the mixture. In this study, a separate PDE for the mass conservation of the liquid water is solved to calculate the saturation levels. The capillary pressure was used to determine the slip velocity between the phases. A full compressible form of the momentum equation was used, with the ∇.V preserved in the equation. The Maxwell-Stefan equation was used to model the diffusive fluxes of the multi-component gas mixture. The strongly coupled equations are solved based on a recently developed finite volume SIMPLER scheme of S.V. Patankar, Numerical Heat Transfer and Fluid Flow, Hemisphere Publishing Corp., McGraw-Hill Book Company, 1984. The computational domain consists of two regions; an open area (gas delivery channel) linked to a porous gas diffusion layer (GDL). A single (unified) set of the PDE's are used for the whole domain with the corresponding properties of each sub-domain. A polarization curve for the whole spectrum of the dry and wet regions were obtained. The results were compared with the experiments of E.A. Ticianelli, C.R. Derouin, A. Redondo, S. Srinivasan, J. Electrochem. Soc. 135 (1988) 2209, and good agreements were achieved

  16. Compressed Air Energy Storage Using Saline Aquifer as Storage Reservior%压缩空气地下咸水含水层储能技术

    Institute of Scientific and Technical Information of China (English)

    胡贤贤; 张可霓; 郭朝斌

    2014-01-01

    Energy crisis and greenhouse effect have promoted the utilization of renewable energy. Energy storage technology is an indispensable part in solving the fluctuation problem for the utilization of solar energy, wind energy, etc. Compressed air energy storage (CAES) technology is the second large energy storage potential just after the pumped hydro storage technology. At present, reservoirs for the CAES are usually underground caverns which are highly limited by geological conditions. Using saline aquifer as the storage reservoir can extend the utilization of the CAES. Herein, the operation principle, advantages and disadvantages of CAES plant are introduced. The feasibility, problems and the key technologies used in aquifer CAES such as the residual hydrocarbons, oxidation, corrosion, particulates and the choice of cushion gas are discussed. This study concludes that the use of saline aquifer as storage reservoir will be an important way to extend the application of CAES.%能源危机和温室效应促进了可再生能源的利用,储能技术是解决太阳能、风能波动问题的重要手段。压缩空气储能(Compressed Air Energy Storage, CAES)技术是仅次于抽水蓄能的第二大蓄能技术。目前CAES多是通过洞穴实现,其主要缺点是对地质要求较高,合适的洞穴数量有限,为扩大其应用,可使用地下咸水含水层作为储层。本文介绍了 CAES 电站的工作原理、优缺点及各国的发展现状,并分析了利用地下咸水含水层进行压缩空气储能的可行性、优点及一些问题与技术方法,如储层内残余烃的影响、氧化与腐蚀作用、颗粒的影响及缓冲气的选择,表明含水层CAES将是拓宽CAES应用的重要途径。

  17. Domesticeringen af Ford i Danmark

    DEFF Research Database (Denmark)

    Wagner, Michael

    med en markedsandel på mere end 50%. En position som Ford måtte afgive til General Motors i løbet af årtiet. I Danmark var mere end hvert andet indregistreret automobil i 1930 antageligt af mærket Ford, og helt frem til verdenskrigens udbrud var Ford Motor Company et brand, som spillede en meget...... markant rolle i den danske offentlighed. Dette paper undersøger hvordan og med hvilke midler, Fords brand image blev formidlet gennem virksomhedens handlinger og gennem reklamer for firmaets produkter i den danske motor-offentlighed. Der var tale om en helt ny type offentlighed, som i bogstaveligste...

  18. Vaccination af slagtekalve mod BRSV

    DEFF Research Database (Denmark)

    Graumann, Anne Mette; Larsen, Lars Erik

    2009-01-01

    Rspiratory Suncytial Virus) blev fundet til at være den typisk fundne virus, der forårsager lungebetændelse. Vacciner imod BRSV er tilgængelige på markedet, men de er aldrig blevt afprøvet systematisk under danske forhold. Formålet med dette forsøg er at undersøge effekten af to forskellige...

  19. Control of oil-wetting on technical textiles by means of photo-chemical surface modification and its relevance to the performance of compressed air filters

    Energy Technology Data Exchange (ETDEWEB)

    Bahners, Thomas, E-mail: bahners@dtnw.de [Deutsches Textilforschungszentrum Nord-West gGmbH (DTNW), Adlerstr. 1, 47798 Krefeld (Germany); Mölter-Siemens, Wolfgang; Haep, Stefan [Institut für Energie- und Umwelttechnik e.V. (IUTA), Bliersheimer Str. 60, 47229 Duisburg (Germany); Gutmann, Jochen S. [Deutsches Textilforschungszentrum Nord-West gGmbH (DTNW), Adlerstr. 1, 47798 Krefeld (Germany); Universität Duisburg-Essen, Physikalische Chemie and CENIDE, Universitätsstr. 2, 45141 Essen (Germany)

    2014-09-15

    Highlights: • The oil repellence of textile fabrics was increased following the Wenzel concept. • Fiber surfaces were micro-roughened by means of pulsed UV laser irradiation. • Subsequent UV-induced grafting yielded pronounced oil repellence. • The grafting process conserved the delicate topography of the fiber surfaces. • The modified fabrics showed favorable drainage behavior in oil droplet separation. - Abstract: A two-step process comprising a surface roughening step by excimer laser irradiation and a post-treatment by photo-grafting to decrease the surface free energy was employed to increase the oil repellence of technical fabrics made of poly(ethylene terephthalate) (PET). The modification was designed to improve the performance of multi-layer filters for compressed air filtration, in which the fabrics served to remove, i.e. drain, oil separated from the air stream. In detail, the fibers surfaces were roughened by applying several laser pulses at a wavelength of 248 nm and subsequently photo-grafted with 1H,1H,2H,2H-perfluoro-decyl acrylate (PPFDA). The oil wetting behavior was increased by the treatments from full wetting on the as-received fabrics to highly repellent with oil contact angles of (131 ± 7)°. On surfaces in the latter state, oil droplets did not spread or penetrate even after one day. The grafting of PPFDA alone without any surface roughening yielded an oil contact angle of (97 ± 11)°. However, the droplet completely penetrated the fabric over a period of one day. The drainage performance was characterized by recording the pressure drop over a two-layer model filter as a function of time. The results proved the potential of the treatment, which reduced the flow resistance after 1-h operation by approximately 25%.

  20. Control of oil-wetting on technical textiles by means of photo-chemical surface modification and its relevance to the performance of compressed air filters

    International Nuclear Information System (INIS)

    Highlights: • The oil repellence of textile fabrics was increased following the Wenzel concept. • Fiber surfaces were micro-roughened by means of pulsed UV laser irradiation. • Subsequent UV-induced grafting yielded pronounced oil repellence. • The grafting process conserved the delicate topography of the fiber surfaces. • The modified fabrics showed favorable drainage behavior in oil droplet separation. - Abstract: A two-step process comprising a surface roughening step by excimer laser irradiation and a post-treatment by photo-grafting to decrease the surface free energy was employed to increase the oil repellence of technical fabrics made of poly(ethylene terephthalate) (PET). The modification was designed to improve the performance of multi-layer filters for compressed air filtration, in which the fabrics served to remove, i.e. drain, oil separated from the air stream. In detail, the fibers surfaces were roughened by applying several laser pulses at a wavelength of 248 nm and subsequently photo-grafted with 1H,1H,2H,2H-perfluoro-decyl acrylate (PPFDA). The oil wetting behavior was increased by the treatments from full wetting on the as-received fabrics to highly repellent with oil contact angles of (131 ± 7)°. On surfaces in the latter state, oil droplets did not spread or penetrate even after one day. The grafting of PPFDA alone without any surface roughening yielded an oil contact angle of (97 ± 11)°. However, the droplet completely penetrated the fabric over a period of one day. The drainage performance was characterized by recording the pressure drop over a two-layer model filter as a function of time. The results proved the potential of the treatment, which reduced the flow resistance after 1-h operation by approximately 25%

  1. Air

    Science.gov (United States)

    ... house) Industrial emissions (like smoke and chemicals from factories) Household cleaners (spray cleaners, air fresheners) Car emissions (like carbon monoxide) *All of these things make up “particle pollution.” They mostly come from cars, trucks, buses, and ...

  2. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 1. Executive summary. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    Potomac Electric Power Company (PEPCO) and Acres American Incorporated (AAI) have carried out a preliminary design study of water-compensated Compressed Air Energy Storage (CAES) and Underground Pumped Hydroelectric (UPH) plants for siting in geological conditions suitable for hard rock excavations. The work was carried out over a period of three years and was sponsored by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI) and PEPCO. The study was divided into five primary tasks as follows: establishment of design criteria and analysis of impact on power system; selection of site and establishment of site characteristics; formulation of design approaches; assessment of environmental and safety aspects; and preparation of preliminary design of plant. The salient aspects considered and the conclusions reached during the consideration of the five primary tasks for both CAES and UPH are presented in this Executive Summary, which forms Volume 1 of the series of reports prepared during the study. The investigations and analyses carried out, together with the results and conclusions reached, are described in detail in Volumes 2 through 13 and ten appendices.

  3. Lessons from Iowa : development of a 270 megawatt compressed air energy storage project in midwest Independent System Operator : a study for the DOE Energy Storage Systems Program.

    Energy Technology Data Exchange (ETDEWEB)

    Holst, Kent (Iowa Stored Energy Plant Agency, Traer, IA); Huff, Georgianne; Schulte, Robert H. (Schulte Associates LLC, Northfield, MN); Critelli, Nicholas (Critelli Law Office PC, Des Moines, IA)

    2012-01-01

    The Iowa Stored Energy Park was an innovative, 270 Megawatt, $400 million compressed air energy storage (CAES) project proposed for in-service near Des Moines, Iowa, in 2015. After eight years in development the project was terminated because of site geological limitations. However, much was learned in the development process regarding what it takes to do a utility-scale, bulk energy storage facility and coordinate it with regional renewable wind energy resources in an Independent System Operator (ISO) marketplace. Lessons include the costs and long-term economics of a CAES facility compared to conventional natural gas-fired generation alternatives; market, legislative, and contract issues related to enabling energy storage in an ISO market; the importance of due diligence in project management; and community relations and marketing for siting of large energy projects. Although many of the lessons relate to CAES applications in particular, most of the lessons learned are independent of site location or geology, or even the particular energy storage technology involved.

  4. Thermodynamic analysis of energy conversion and transfer in hybrid system consisting of wind turbine and advanced adiabatic compressed air energy storage

    International Nuclear Information System (INIS)

    A simulation model consisting of wind speed, wind turbine and AA-CAES (advanced adiabatic compressed air energy storage) system is developed in this paper, and thermodynamic analysis on energy conversion and transfer in hybrid system is carried out. The impacts of stable wind speed and unstable wind speed on the hybrid system are analyzed and compared from the viewpoint of energy conversion and system efficiency. Besides, energy conversion relationship between wind turbine and AA-CAES system is investigated on the basis of process analysis. The results show that there are several different forms of energy in hybrid system, which have distinct conversion relationship. As to wind turbine, power coefficient determines wind energy utilization efficiency, and in AA-CAES system, it is compressor efficiency that mainly affects energy conversion efficiencies of other components. The strength and fluctuation of wind speed have a direct impact on energy conversion efficiencies of components of hybrid system, and within proper wind speed scope, the maximum of system efficiency could be expected. - Highlights: • A hybrid system consisting of wind, wind turbine and AA-CAES system is established. • Energy conversion in hybrid system with stable and unstable wind speed is analyzed. • Maximum efficiency of hybrid system can be reached within proper wind speed scope. • Thermal energy change in hybrid system is more sensitive to wind speed change. • Compressor efficiency can affect other efficiencies in AA-CAES system

  5. Ultraspectral sounder data compression review

    Institute of Scientific and Technical Information of China (English)

    Bormin HUANG; Hunglung HUANG

    2008-01-01

    Ultraspectral sounders provide an enormous amount of measurements to advance our knowledge of weather and climate applications. The use of robust data compression techniques will be beneficial for ultraspectral data transfer and archiving. This paper reviews the progress in lossless compression of ultra-spectral sounder data. Various transform-based, pre-diction-based, and clustering-based compression methods are covered. Also studied is a preprocessing scheme for data reordering to improve compression gains. All the coding experiments are performed on the ultraspectral compression benchmark dataset col-lected from the NASA Atmospheric Infrared Sounder (AIRS) observations.

  6. Air

    International Nuclear Information System (INIS)

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  7. Vurdering af sikkerhedsniveau for betonelementer

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    I dette notat vurderes muligheden for at anvende partialkoefficienterne i tillægget til kapitel 5 til DS411 (2006) sammen med DS409:1998, DS410:1998 og DS 411:1998 (1998 normerne). Da det i henhold til bl.a. DS409 ikke umiddelbart er tilladt at blande partialkoefficienter (og andre regler) i fors...... forskellige normsystemer, undersøges i dette notat specifikke tilfælde, hvor mindst samme sikker-hedsniveau opnås ved ovennævnte kombination af partialkoefficienter og normsystemer....

  8. Afgivelse af formaldehyd fra byggevarer og forbrugerprodukter

    DEFF Research Database (Denmark)

    Kolarik, Barbara; Gunnarsen, Lars; Funch, Llis Winther

    Rapporten præsenterer resultatet af en undersøgelse af formaldehydafgivelse fra 22 mulige kilder i indeklimaet. Undersøgelsen er gennemført for om muligt at finde årsagen til de høje koncentrationer af formaldehyd i indeluften, der blev fundet i enkelte danske boliger under en foregående undersøg......Rapporten præsenterer resultatet af en undersøgelse af formaldehydafgivelse fra 22 mulige kilder i indeklimaet. Undersøgelsen er gennemført for om muligt at finde årsagen til de høje koncentrationer af formaldehyd i indeluften, der blev fundet i enkelte danske boliger under en foregående...

  9. Regulering af jødiske kroppe

    DEFF Research Database (Denmark)

    Schleicher, Marianne

    2014-01-01

    på teori dels af Michel Foucault om, hvordan kultur sikrer sin egen overlevelse ved at indsamle viden om bl.a. kroppe med henblik på at regulere brugen af dem, dels af Judith Butler, der bl.a. forklarer, hvordan kultur trods alt er åben for såkaldt subversion, idet det bidrager til at udvide og...... udvikle kulturens normer og heraf følgende regulering af bl.a. kroppe. I de dele af undersøgelsen, hvor selve udviklingen af kropsopfattelser er i fokus, trækkes der endvidere på religionssociologen Robert Bellahs og psykologen Merlin Donalds teorier om kulturel evolution med henblik på at formulere...

  10. Depressive patienters oplevelse af at modtage ECT

    DEFF Research Database (Denmark)

    Jensen, Christine Damsbo

    Dette studie handler om, hvordan det opleves for den voksne depressive patient at gennemgå et ECT-behandlingsforløb (electroconvulsive therapy). Formålet med projektet er dels at undersøge, hvordan processen omkring ECT-behandlingen udspiller sig og dels at undersøge patienternes oplevelse......, reaktioner og tanker omkring ECT-behandlingen. Studiet bygger på den eksisterende viden om patienters oplevelse af ECT. Metoden er feltforskning med deltagende observation og etnografisk interview. Dette suppleres af to spørgeskemaer. Der blev inkluderet 8 patienter i undersøgelsen. Analysen udspringer af...... konstruktivistisk epistemiologisk vinkel. Ved en teoristyret analyse fremkom 2 overordnede temaer: Anspændthed og tryghed. Disse temaer blev behandlet i en procesorienteret forståelse af ECT-forløbet. Denne proces bestod af: Betingelser, interaktion og konsekvenser. Diskussionen er en kritisk diskussion af fund og...

  11. Konceptuelt design og udvikling af Intergomus

    DEFF Research Database (Denmark)

    Ellebæk, P.; Pedersen, T.; Stendal, Karsten; Sejr, K.

    1999-01-01

    Denne rapport gennemgår udviklingsforløbet af et træningsapparat til genoptræning af læderede fingre. Rapporten omhandler kun den mekaniske del af udstyret. Opgaven er blevet løst i samarbejde med Ergoterapien på Køge Amtssygehus, Procare, Centret forAvanceret Teknologi og flere afdelinger på RIS...

  12. Bliver fjernvarmen en del af fremtidens energisystem?

    OpenAIRE

    Münster, Marie; Hansen, Lise-Lotte Pade

    2007-01-01

    Fjernvarmen er ikke i fokus, når forskere og politikere analyserer fremtidens energisystem. Det viser et litteraturstudie af dansk og international litteratur om fjernvarmens rolle i fremtidens energisystem. Projektet kan ses på www.danskfjernvarme.dk. I litteraturstudiet er 15 danske og internationale databaser afsøgt for litteratur om fjernvarmens rolle i fremtiden. 45 Artikler og rapporter blev udvalgt. Resultatet af litteraturstudieter blandt andet, at:• der findes kun få videnskabelige a...

  13. Forskningsoversigt - Effekterne af Cooperative Learning

    DEFF Research Database (Denmark)

    Larsen, Lea Lund

    Kan Cooperative Learning - en undervisningsform hvor lærerens tid ved tavlen mindskes og hvor de lærende samarbejder om stoffet - maksimere de lærendes indlæring og medvirke til en forbedring af deres interpersonelle og kommunikative kompetencer, samt øge deres motivation for læring? Den megen...... forskning fra USA viser, at Cooperative Learning øger lærerens bevidsthed om, hvilken adfærd, han er medvirkende til at skabe blandt de lærende. Og den øger lærerens bevidsthed omkring interaktioner i klasserummet, og giver god plads og taletid til hver enkelt lærende. Set i lyset heraf kan Cooperative......, at Cooperative Learning har lige så høj grad af positiv effekt, som den viser sig at have på grundskoleområdet. Det er sigtet med denne oversigt over den empiriske forskning. Til start præsenteres Cooperative Learning som metode, dens rødder og udvikling, dernæst skitseres den omfattende forskning omkring...

  14. NIR optimerer produktionen af gammeldags modnede sild

    DEFF Research Database (Denmark)

    Svensson, Vibeke Tølbøl; Bro, Rasmus; Nielsen, Henrik Hauch; Volmer, Susanne

    Måling med nærinfrarødt (NIR) lys er et godt supplement til de nuværende metoder til at følge modningen af sild saltede i tønder. Det viser resultaterne af et forskningsprojekt udført i samarbejde mellem Lykkeberg A/S, Danmarks Fiskeriundersøgelser og Den Kgl Veterinær- og Landbohøjskole. Ved hjælp...... af avanceret matematik er det nemt og hurtigt at bestemme modningsgraden af sild direkte fra en NIR måling....

  15. Kvægbedriften - udledning af drivhusgasser

    OpenAIRE

    Kristensen, Troels; Mogensen, Lisbeth

    2011-01-01

    Med et klimaregnskab for kvægbedriften får driftslederen et grundlag for at vurdere bedriftens status og muligheder for at nedbringe udledningen af drivhusgasser. I klimaregnskabet er den enkelte bedrifts årlige udledningen af klimagasser fra produktion og forbrug af foder, gødning og andre driftsfaktorer beregnet som summen af drivhusgasserne metan, lattergas og kuldioxid. Den samlede udledning er efterfølgende fordelt på produkterne mælk, kød og salgsafgrøder. I denne artikel beskrives grun...

  16. Opstilling af ventilationsarmaturer i CFD-beregninger

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    2009-01-01

    Opstilling af armaturer i CFD-beregninger er et område, hvor ventilationsbranchen skal tilføre CFD-metoderne en specialviden, som ikke på forhånd er indlagt i programmerne. I artiklen bringes nogle eksempler på specificering af en indblæsningsåbning......Opstilling af armaturer i CFD-beregninger er et område, hvor ventilationsbranchen skal tilføre CFD-metoderne en specialviden, som ikke på forhånd er indlagt i programmerne. I artiklen bringes nogle eksempler på specificering af en indblæsningsåbning...

  17. Geotechnical Feasibility Analysis of Compressed Air Energy Storage (CAES) in Bedded Salt Formations: a Case Study in Huai'an City, China

    Science.gov (United States)

    Zhang, Guimin; Li, Yinping; Daemen, Jaak J. K.; Yang, Chunhe; Wu, Yu; Zhang, Kai; Chen, Yanlong

    2015-09-01

    The lower reaches of the Yangtze River is one of the most developed regions in China. It is desirable to build compressed air energy storage (CAES) power plants in this area to ensure the safety, stability, and economic operation of the power network. Geotechnical feasibility analysis was carried out for CAES in impure bedded salt formations in Huai'an City, China, located in this region. First, geological investigation revealed that the salt groups in the Zhangxing Block meet the basic geological conditions for CAES storage, even though the possible unfavorable characteristics of the salt formations include bedding and different percentages of impurities. Second, mechanical tests were carried out to determine the mechanical characteristics of the bedded salt formations. It is encouraging that the samples did not fail even when they had undergone large creep deformation. Finally, numerical simulation was performed to evaluate the stability and volume shrinkage of the CAES under the following conditions: the shape of a single cavern is that of a pear; the width of the pillar is adopted as two times the largest diameter; three regular operating patterns were adopted for two operating caverns (internal pressure 9-10.5 MPa, 10-11.5 MPa, and 11-12.5 MPa), while the other two were kept at high pressure (internal pressure 10.5, 11.5, and 12.5 MPa) as backups; an emergency operating pattern in which two operating caverns were kept at atmospheric pressure (0.1 MPa) for emergency while the backups were under operation (9-10.5 MPa), simulated for 12 months at the beginning of the 5th year. The results of the analysis for the plastic zone, displacement, and volume shrinkage support the feasibility of the construction of an underground CAES power station.

  18. A preliminary dynamic behaviors analysis of a hybrid energy storage system based on adiabatic compressed air energy storage and flywheel energy storage system for wind power application

    International Nuclear Information System (INIS)

    Integrating energy storage system into wind system can mitigate the negative effects caused by the intermittent wind. In addition, the spectrum analysis of wind power implies that the hybrid energy storage system may have better performance on smoothing out the wind power fluctuations than the independent energy storage system. The main advantage of the hybrid energy storage system is the multi-response speeds. Also, the hybrid energy storage system often operates in the modes switch, partial load and frequent start/stop conditions. Thus, the dynamic behaviors of each devices and the assembly of hybrid energy storage system are important for the system operation and control system design. The design, off-design analysis and parametric analysis of a wind-hybrid energy storage system consisting an A-CAES (adiabatic compressed air energy storage) system and a FESS (flywheel energy storage system) based on spectrum analysis method are carried out in the previous paper (P Zhao et al., 2014). This paper will conduct a preliminary dynamic behaviors analysis of the proposed wind-hybrid energy storage system based on the dynamic models. The simulation results indicate that the total power of wind-hybrid energy storage system can fit the load requirement well, providing an efficient power management for wind power penetration. - Highlights: • A hybrid energy storage system based on A-CAES and FESS is proposed. • Dynamic model of a wind-hybrid energy storage system is laid out. • Dynamic behaviors of wind-hybrid energy storage system are investigated. • The power output of wind-hybrid energy storage system can fit the load well

  19. Mechanical stability of a salt cavern submitted to rapid pressure variations: Application to the underground storage of natural gas, compressed air and hydrogen

    International Nuclear Information System (INIS)

    Salt caverns used for the underground storage of large volumes of natural gas are in high demand given the ever-increasing energy needs. The storage of renewable energy is also envisaged in these salt caverns for example, storage of compressed air and hydrogen mass storage. In both cases, salt caverns are more solicited than before because they are subject to rapid injection and withdrawal rates. These new operating modes raise new mechanical problems, illustrated in particular by sloughing, and falling of overhanging blocks at cavern wall. Indeed, to the purely mechanical stress related to changes in gas pressure variations, repeated dozens of degrees Celsius of temperature variation are superimposed; causes in particular during withdrawal, additional tensile stresses whom may lead to fractures at cavern wall; whose evolution could be dangerous. The mechanical behavior of rock salt is known: it is elasto-viscoplastic, nonlinear and highly thermo sensitive. The existing rock salt constitutive laws and failures and damages criteria have been used to analyze the behavior of caverns under the effects of these new loading. The study deals with the thermo mechanics of rocks and helps to analyze the effects of these new operations modes on the structural stability of salt caverns. The approach was to firstly design and validate a thermodynamic model of the behavior of gas in the cavern. This model was used to analyze blowout in gas salt cavern. Then, with the thermo mechanical coupling, to analyze the effects of rapid withdrawal, rapid injection and daily cycles on the structural stability of caverns. At the experimental level, we sought the optimal conditions to the occurrence and the development of cracks on a pastille and a block of rock salt. The creep behavior of rock salt specimens in triaxial extension also was analyzed. (author)

  20. Empilhamento de ar e compressão torácica aumentam o pico de fluxo da tosse em pacientes com distrofia muscular de Duchenne Air stacking and chest compression increase peak cough flow in patients with Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Magneide Fernandes Brito

    2009-10-01

    Full Text Available OBJETIVO: Avaliar a eficiência da tosse através do uso de duas manobras manuais de auxílio à tosse. MÉTODOS: Foram selecionados 28 pacientes portadores de distrofia muscular de Duchenne em uso de ventilação mecânica não-invasiva noturna e CVF OBJECTIVE: To evaluate cough efficiency using two manually-assisted cough techniques. METHODS: We selected 28 patients with Duchenne muscular dystrophy. The patients were receiving noninvasive nocturnal ventilatory support and presented FVC values < 60% of predicted. Peak cough flow (PCF was measured, with the patient seated, at four time points: at baseline, during a spontaneous maximal expiratory effort (MEE; during an MEE while receiving chest compression; during an MEE after air stacking with a manual resuscitation bag; and during an MEE with air stacking and compression (combined technique. The last three measurements were conducted in random order. The results were compared using Pearson's correlation test and ANOVA with repeated measures, followed by Tukey's post-hoc test (p < 0.05. RESULTS: The mean age of the patients was 20 ± 4 years, and the mean FVC was 29 ± 12%. Mean PCF at baseline, with chest compression, after air stacking and with the use of the combined technique was 171 ± 67, 231 ± 81, 225 ± 80, and 292 ± 86 L/min, respectively. The results obtained with the use of the combined technique were significantly better than were those obtained with the use of either technique alone (F[3.69] = 67.07; p < 0.001. CONCLUSIONS: Both chest compression and air stacking techniques were efficient in increasing PCF. However, the combination of these two techniques had a significant additional effect (p < 0.0001.

  1. Hypervirkelig(?). Studier af ungdom, skole og modernitet i udkanten af Kathmandu

    DEFF Research Database (Denmark)

    Madsen, Ulla Ambrosius

    2010-01-01

    Med udgangspunkt i etnografiske studier af ungdom og skoleliv i udkanten af Kathmandu, analyserer artiklen samspillet mellem 'det moderne', uddannelse og identitet blandt unge der lever i udkanten af den globale periferi.I modsætning til studier der beskæftiger sig med om og hvordan uddannelse bi...... fremtiden. Teoretisk trækker deres på begreber og positioner fra postmoderne metodologiskeog filosofiske orienteringer - repræsenteret blandt andre af Popkewitz, Maclure og Baudrillard....

  2. Måling af friktion ved hjælp af spindelpressen

    DEFF Research Database (Denmark)

    Henningsen, Poul

    Teknisk Manual. Denne rapport gennemgår forsøgsopstillinger på spindelpressen til måling af friktion. Der bliver kort gennemgået hvilket udstyr der skal bruges, og hvordan data opsamles og transducerne kalibreres. Rapporten er en hjælp til opstilling af udstyret. Beskrivelser af testprincipper og...

  3. Midler til lindring af mundtørhed og stimulation af spytsekretion

    DEFF Research Database (Denmark)

    Dynesen, Anja Weirsøe; Pedersen, Anne Marie Lynge; Bardow, Allan;

    2013-01-01

    effekt. I relation til risikoen for at udvikle caries, der er forhøjet hos den mundtørre patient, er det dog væsentligt at anbefale produkter uden sukker. Ligesom produktets indhold af syre og dermed det erosive potentiale er af betydning i forhold til udviklingen af dentale erosioner. Systemisk...

  4.  DMU's vurdering af problemer vedrørende udvikling af glyfosatresistens som følge af anvendelsen af glyfosat i glyfosattolerante afgrøder, set i dansk sammenhæng

    DEFF Research Database (Denmark)

    Strandberg, Morten Tune

    2010-01-01

    hinanden følgende år. Det resistente ukrudt vil, hvis der ikke indføres tiltag der reducerer udviklingen af resistent ukrudt, medføre at anvendelsen af herbicider forøges, hvilket igen potentielt vil øge belastningen af natur og miljø. Det er ved anvendelse af nogle simple forholdsregler i dyrkningen af...

  5. Time Compression

    OpenAIRE

    Aadland, David; Shaffer, Sherrill

    2012-01-01

    Economists have generally ignored the notion that perceived time may differ from clock time. Borrowing from the behavioral psychology literature, we investigate the case of time compression whereby perceived time passes more quickly than actual time. A framework is presented to embed time compression in economic models. We then apply the principle to a standard lifecycle permanent income model with endogenous labor. Time compression provides an alternative explanation of why older indi...

  6. I skyggen af den tyske stormagt

    DEFF Research Database (Denmark)

    Lammers, Karl Christian

    2011-01-01

    Undersøgelse af de hemmelige dansk- tyske militærsonderinger fra 1906 om evt. militært samarbejde......Undersøgelse af de hemmelige dansk- tyske militærsonderinger fra 1906 om evt. militært samarbejde...

  7. Guide til evaluering af Den motiverende samtale

    DEFF Research Database (Denmark)

    Lunde, Anita; Douw, Karla

    , den er forståelig, overskuelig og nem at gå til SEG mangler en bedre beskrivelse af konteksten (eksempelvis hvilken type borger og om samtalen var planlagt) og har tendens til at virke overfladisk Boksen om samtalens struktur i SEG giver store problemer, idet der ofte vil svares nej på trods af...

  8. Didaktisk design af et pervasive learning game

    DEFF Research Database (Denmark)

    Oldenskov, Joakim; Westergren, Jens; Frank, Anders Bredahl

    2010-01-01

    Projektet er et studie i det teoretiske grundlag for, og en empirisk undersøgelse, af en prototype for et didaktisk design af et pervasive learning game. Der arbejdes overordnet med udviklingen af et didaktisk design af et læringsspil som kombinerer mobile teknologier, det fysiske rum og eleverne...... game med en analyse af legen og motivationen iboende spillet. I det læringsteoretiske felt inddrages og diskuteres forskellige tilgange til læring og pervasive games, som alle repræsenterer et socialkonstruktivistisk syn på læring. Det didaktiske design danner grundlag for et prototypedesign af et...... navigation og opgaveløsning. Undersøgelsen viser didaktisk designs potentiale i forhold til den operationelle del af it-undervisningen. Begrebet Pervasive Learning Game åbner nogle muligheder for at inddrage nye medier kombineret med en remediering af allerede kendte medier i bestræbelserne på at danne og...

  9. Planlægning af laboratorier

    DEFF Research Database (Denmark)

    Registrering af bygherrens eller brugernes krav til bygningernes omfang, udformning og indretning er første fase i en byggeopgaves programlægning. Denne anvisning giver en oversigt over de spørgsmål, som bør være afklarede og indeholdt i byggeprogrammet som basis for projektering af laboratorieby...

  10. Medieleg af 1. og 2. grad

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    : Medieleg af 1. og 2. grad. Luhmann definerer systemer som “enheder, der lader sig skelne fra deres omverden” og hvor denne skelnen gælder “både for ydre iagttagere og […] for selviagttagelse” (Luhmann 1997, p.46). I denne artikels kontekst, kan denne systemiske opfattelse af leg ses i sammenhæng med...

  11. Medieleg af 1. og 2. grad

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    Niklas Luhmanns forståelse af menneskelig aktivitet som sociale systemer foreslå at medieleg kan deles op i to forskellige - men nært forbundne - begreber: Medieleg af 1. og 2. grad. Luhmann definerer systemer som "enheder, der lader sig skelne fra deres omverden" og hvor denne skelnen gælder "både for...

  12. Måling af virksomheders administrative byrder

    DEFF Research Database (Denmark)

    Langsted, Lars Bo

    2004-01-01

    Selskabsstyrelsen har offentliggjort rapporten: "Rapport om måling af virksomhedernes administrative byrder ved årsregnskabsloven og rapport om revisionshonorar for B-virksomheder."......Selskabsstyrelsen har offentliggjort rapporten: "Rapport om måling af virksomhedernes administrative byrder ved årsregnskabsloven og rapport om revisionshonorar for B-virksomheder."...

  13. Grønland stiger af havet

    DEFF Research Database (Denmark)

    Laursen, Steen; Khan, Shfaqat Abbas

    En af de varme sommernyheder er, at Grønlands bjergtinder stiger mod himmelen i takt med, at indlandsisen tynder ud. Det viser dansk forskning, som bliver bakket op af amerikanske målinger fra Nasa. Newton har besøgt Nasa på Grønland og interviewet den danske forsker bag de nye resultater....

  14. Lys, ilt og vands nedbrydning af maling

    DEFF Research Database (Denmark)

    Kiil, Søren

    Udendørsmaling forvitrer gennem en række fysiske og kemiske mekanismer. En ingeniørmæssig forståelse af nedbrydningsprocesserne giver et solidt grundlag for at fortolke data fra acceæererede test og for at vurdere relevansen af en given test....

  15. Fastholdelse af erhvervsskoleelever i det danske erhvervsuddannelsessystem

    DEFF Research Database (Denmark)

    Nielsen, Klaus; Jørgensen, Christian Helms; Koudahl, Peter;

    2013-01-01

    Forskningsprojektet ”Retention of Vocational Students in the Danish VET System” undersøger de påvirkelige faktorer, der kan bidrage til at mindske frafaldet på de erhvervsfaglige uddannelser (EUD). For etablering af en sådan viden er dannet et konsortium bestående af såvel forskere med stor...

  16. Udforskning af dialoger om et regnehul

    DEFF Research Database (Denmark)

    Lindenskov, Lena

    Med introduktionen af det danske begreb 'regnehuller' om matematikvanskeligheder bliver det muligt at udforske dialoger i klasserummet med brug af værktøjer fra Augusto Boals Forumteater. Principperne i Boals tre faser præsenteres som værktøjer for læreres refleksive praksis. Ud fra datamateriale...

  17. Prioriteringer af efterretninger i kampen mod terror

    DEFF Research Database (Denmark)

    Nielsen, Thomas Galasz

    2015-01-01

    Efterretningstjenesterne indsamler stadig flere informationer i forsøget på at opdage og imødegå terrorister. Men mængden af informationer gør det ikke nødvendigvis lettere at forudsige terrorhandlinger. Efterretningstjenesterne bør derfor prioritere bearbejdning af oplysningerne højere, end de g...

  18. Faldende incidens af kirurgisk behandlet kolesteatom

    DEFF Research Database (Denmark)

    Djurhuus, Bjarki; Faber, Christian; Skytthe, Axel

    2010-01-01

    Dette er et resume af en originalartikel publiceret på www.danmedbul.dk som Dan Med Bul 2010;57(10):A4186......Dette er et resume af en originalartikel publiceret på www.danmedbul.dk som Dan Med Bul 2010;57(10):A4186...

  19. Environmental assessment of speeding up use of particle filters on passenger cars and vans. Air quality and population exposure for PM{sub 2.5}; Miljoevurdering af fremskyndelse af partikelfiltre pae person- og varebiler. Luftkvalitet og befolkningseksponering for PM{sub 2.5}

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.; Ketzel, M. [DMU, Afd. for Atmosfaerisk Miljoe (Denmark)

    2006-11-15

    New stringent European Union emission standards for particles are expected to be implemented around 2010 for diesel-powered passenger cars and vans. Provided that such standards are agreed upon diesel-powered passenger cars and vans are expected to be equipped with particle filters that effectively will remove particle emissions. Against this background, the Danish Environmental Assessment Institute wanted to carry out a cost-benefit analysis of a scenario where the emission standards came into force in 2007 instead of 2010. The objective of the project is to assess the effects on particle emissions and air quality of PM{sub 2.5} (particles less than 2.5 micrometer) of moving forward the emission standards for passenger cars and vans. An assessment of a scenario is carried out that assumes that all new diesel-powered passenger cars and vans entering the vehicle fleet during January 1st, 2007 and December 31st, 2009 will be equipped with particle filters. The National Environmental Research Institute has carried out this assessment. (au)

  20. Værdisætning af beskyttelse og rensning af grundvand

    DEFF Research Database (Denmark)

    Hasler, B.; Lundhede, T.; Martinsen, L.;

    Værdierne af grundvandsbeskyttelse og rent drikkevand handles ikke på et marked og de har derfor ikke en pris. Med værdisætningsmetoder er det muligt at beregne befolkningens præferencer af effekterne af grundvandsbeskyttelse og rensning i kroner. Resultaterne af undersøgelsen viser at danskerne...... har en positiv betalingsvilje for at beskytte grundvandet ud over det beløb de betaler for vand i dag. Betalingsviljen for beskyttelse af vandet overstiger betalingsviljen for at rense grundvandet...

  1. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    Science.gov (United States)

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  2. Compressed Teleportation

    CERN Document Server

    Jaffe, Arthur; Wozniakowski, Alex

    2016-01-01

    In a previous paper we introduced holographic software for quantum networks, inspired by work on planar para algebras. This software suggests the definition of a compressed transformation. Here we utilize the software to find a CT protocol to teleport compressed transformations. This protocol serves multiple parties with multiple persons.

  3. Krylov methods for compressible flows

    Science.gov (United States)

    Tidriri, M. D.

    1995-01-01

    We investigate the application of Krylov methods to compressible flows, and the effect of implicit boundary conditions on the implicit solution of nonlinear problems. Two defect-correction procedures, namely, approximate factorization (AF) for structured grids and ILU/GMRES for general grids, are considered. Also considered here are Newton-Krylov matrix-free methods that we combined with the use of mixed discretization schemes in the implicitly defined Jacobian and its preconditioner. Numerical experiments that show the performance of our approaches are then presented.

  4. Kongres IFLA v Buenos Aires

    Czech Academy of Sciences Publication Activity Database

    Burgetová, Jarmila

    -, č. 4 (2004), s. 4-7. ISSN 1210-8502 Keywords : IFLA * International Federation of Library Associations and Institutions * Congress 2004 * Buenos Aires Subject RIV: AF - Documentation, Librarianship, Information Studies

  5. Distribution af video – lige meget hvordan?

    Directory of Open Access Journals (Sweden)

    Diba Markus

    2010-12-01

    Full Text Available Artiklen omhandler løsninger til distribution af video og de faktorer, der kan være udslagsgivende, når man som underviser eller universitet skal vælge, hvilken man vil gøre brug af. De kommercielle løsninger såsom YouTube m.fl. er kendt af de fleste. Hvad færre måske ved er, at der eksisterer alternativer. På europæisk plan har en række institutioner og forskningsnet, herunder det danske, således valgt at lave deres egne løsninger. Der er afgørende forskelle i disse hhv. kommercielle og ikke-kommercielle videodistributionstjenesters tilgange til problemstillinger vedrørende adgangsbegrænsning, ophavsret, metadatering og bevaring samt kvalitetssikring af indhold - forskelle, der for en stor del udspringer af deres respektive opdrag og muligheder for brugerautentificering. Kun de færreste af alternativerne kan bruges af danske studerende og universitetsansatte. Som der argumenteres for i artiklen, er disse problemstillinger imidlertid vigtig baggrundsinformation, når der skal tages stilling til, hvordan man bedst distribuerer videoressourcer. I artiklen beskrives overordnede fællestræk ved hhv. de kommercielle og de ikke-kommercielle distributionsløsninger, og de helt grundliggende forskelle mellem dem diskuteres.

  6. Grade-2 Teflon (AF1601) PCF for optical communication using 2D FDTD technique: a simplest design

    Science.gov (United States)

    Muduli, N.; Achary, J. S. N.; Padhy, Hemanta ku.

    2016-04-01

    A nonlinear ytterbium-doped rectangular proposed PCF structure of inner and outer cladding is used to analyze effective mode field area (Aeff), nonlinear coefficient (γ), dispersion (D), and confinement loss (CL) in a wide range of wavelength. The fabrication of PCF structure is due to different size doped air hole, pitch, and air hole diameter in a regular periodic geometrical array fashion. The various property of PCF structure such as mode field area, nonlinear coefficient, dispersion, and confinement loss are analyzed by implementing 2D FDTD technique. The above PCF property investigated using suitable parameters like Λ1, ?, ?, and ? in three different situations is discussed in simulation. The high nonlinear coefficient and dispersion property of PCF structure are tailored by setting the cladding parameter. However, highly nonlinear fibers with nonzero dispersion at the wavelength of 1.55 μm are very attractive for a range of optical communication application such as laser amplifier, pulse compression, wavelength conversion, all optical switching, and supercontinuum generation. So our newly proposed ytterbium-doped PCF seems to be most suitable exclusively for supercontinuum generation and nonlinear fiber optics. Finally, it is observed that ytterbium-doped Teflon (AF1601) PCF has more nonlinear coefficient (γ(λ) = 65.27 W-1 km-1) as compared to pure silica PCF (γ(λ) = 52 W-1 km-1) design to have same mode field area (Aeff) 1.7 μm2 at an operating wavelength of 1.55 μm.

  7. Instagram - æstetisering af hverdagslivet

    OpenAIRE

    Bach-Dal, Amalie; Breede, Camilla; Hoppe, Ene; Mølgaard, Nina; Karlsson, Sara; Thrane, Kaper

    2013-01-01

    I projektet vil det sociale medie Instagram, blive belyst grundet dets stadig voksende popularitet i vores samfund. I takt med teknologiens udvikling i samfundet samt internettets tilgængelighed for den almene borger, bidrager Instagram til selvfremstilling og æstetisering af hverdagen for brugerne af fotodelings mediet. Projektet redegør for de ændringer og udviklinger, det digitale fotografi har gennemgået frem mod den visuelle fremstilling af hverdagen på internettet i dag. Herefter fø...

  8. Strategier for udredning og behandling af dyspepsi

    DEFF Research Database (Denmark)

    Jarbøl, Dorte Ejg; Kjeldsen, H.C.; Schaffalitzky de Muckadell, Ove B.

    2004-01-01

    almen praksis er empirisk behandling med antisekretorisk medicin, med efterfølgende endoskopi for nonrespondere. Noninvasiv test for Helico-bacter pylori (Hp) efterfulgt af eradikationskur til Hp-positive (Hp- test-and-treat ) er en strategi, der anbefales i flere guidelines til yngre patienter......Dyspepsi er et heterogent symptomkompleks, der dækker over smerte og ubehag i den øvre del af abdomen. Selv om området er genstand for stor opmærksomhed, er der ikke konsensus om den optimale udrednings- og behandlingsstrategi. Den mest anvendte strategi i behandlingen af ikkeundersøgt dyspepsi i...

  9. Reflektion over diskrimination af personer med fedme

    OpenAIRE

    Overbye, Adam Brandt; Møller-Nybye, Andreas; Lysell, Jimmy René; Bunch-Nielsen, Jonathan; Knudsholt, Martin; Commerou, Peter Winther; Papanikolaou, Phoivos Apollon

    2008-01-01

    Fedme er et voksende problem ikke kun i den vestlige verden men også i udviklingslande. Problemet har nået det punkt, hvor det kan kaldes en epidemi. I takt med udbredelsen af fedme er et interessant spørgsmål opstået med hensyn til forskelsbehandlingen af personer med fedme. I hvilken grad er denne forskelsbehandling diskriminerende eller legitim? Der forelægger ingen dokumentation for diskrimination af fedme, men der er dokumentation for fordomme mod personer med fedme. I denne rapport vil ...

  10. Blended Learning Analytics Model for Evaluation (BLAME. Et case-studie af universitetsunderviseres brug af Blackboard

    Directory of Open Access Journals (Sweden)

    Peter Musaeus

    2015-10-01

    Full Text Available I denne artikel vil vi præsentere en strategi til inddragelse af læringsanalytik (learning analytics ved evaluering af universitetsunderviseres brug af et nyt LMS på Aarhus Universitet: Blackboard. Vi diskuterer en model (BLAME: Blended Learning Analytics Model of Evaluation for, hvordan kategorisering af kurser og data om læringsanalytik indsamlet på Blackboard kan integreres. Endvidere belyser vi, hvilke implikationer en sådan læringsanalytik kan have for blended learning ved at analysere to forskellige uddannelses-cases/illustrationer. Dernæst diskuterer vi pædagogisk udvikling i forbindelse med evalueringsrapport om underviseres brug af Blackboard som beslutningsstøtte for feedback og pædagogisk intervention. Artiklen slutter med en diskussion af, hvordan data til læringsanalytik bør indsamles i LMS og bruges til afrapportering og undervisningsudvikling.

  11. Udvikling af sensorsystem for robotbaseret rengøring af svinestalde

    DEFF Research Database (Denmark)

    Andersen, Nils Axel; Braithwaite, Ian David; Sørensen, Torben;

    2005-01-01

    Manuel rengøring af svinestalde er både meget sundhedsskadeligt og samtidig meget uinspirerende. Arbejdsmiljøet forværres løbende under arbejdet da der under rengøringen (med en højtryksrenser) hvirvles snavs, mikroorganismer og vand op, som personalet derefter indånder. DTU er derfor i samarbejde...... med Forskningscenter Bygholm ved at udvikle et sensorsystem til detektering af renhedsgraden med mere, således at dette beskidte staldvaskarbejde kan automatiseres med en vaskerobot. Med et fleksibelt sensorsystem bliver vaskerobotten en intelligent servicerobotløsning til rengøring af svinestalde og...... forbedre de nuværende arbejdsbetingelser for staldpersonalet. Selvom der her fokuseres på rensning af svinestalde forventes det, at sensorsystemet på sigt ville kunne anvendes i forbindelse med rensning af en bred vifte af bygninger inden for fødevareindustrien og andre industrier med et lignende behov....

  12. Global opvarmning neutraliserer effekten af parasitisme på strandsnegles konsumption af makroalger

    DEFF Research Database (Denmark)

    Larsen, Martin H.; Mouritsen, Kim Nørgaard

    trematode-inficerede strandsnegle vil øge deres konsumptionsrate under varmere forhold for at imødekomme de ekstra energiomkostninger, der er forbundet med den øgede produktion af cercarier. Vores hypotese var derfor, at kombinationen af global opvarmning og parasitisme kan neutralisere den nuværende...... negative effekt, trematode-infektioner har på strandsneglens konsumption af grønne makroalger. For at teste denne hypotese undersøgte vi den kombinerede effekt af temperatur og infektion på strandsneglenes konsumption af makroalgen Ulva lactuca i et mikrokosmos eksperiment. Eksperimentet viste en markant...... synergieffekt af parasitisme og temperatur på konsumptionsraten hos store strandsnegle (³ 1,1 g våd vægt). Mens inficerede snegle havde lavere konsumptionsrate end uinficerede individer ved 18 ºC, var der ingen forskel ved 21 ºC. Det tyder derfor på, at synergien mellem parasitisme og en realistisk...

  13. Elektrokemisk fjernelse af cadmium fra bioasker

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter;

    Hosliggende rapport formidler resultaterne fra PSO-projektet: ”Elektrokemisk fjernelse af cadmium fra bioasker” (PSO-F&U 3206), finansieret af Elkraft System og Energi E2 A/S. Projektet blev gennemført i perioden 01.05.2003 – 30.06.2004, og partnerne var Energi E2 A/S, BYG-DTU og Krüger A/S, med ...... igangværende PSO FU 2201 ”Opgradering af restprodukter” (”Askepot”), og det skulle derfor også undersøges, om den elektrodialytiske rensningsproces evt. kunne kombineres med den vaskeproces, der benyttes til rensning af aske i FU 2201....

  14. Selektiv avl af racehunde og -katte

    DEFF Research Database (Denmark)

    Sandøe, Peter; Meyer, Iben Helene Coakley; Fredholm, Merete;

    2014-01-01

    Dette kapitel ser nærmere på de velfærdsmæssige problemstillinger, der opstår som følge af måden, hvorpå racehunde og -katte påvirkes gennem selektiv avl. Først beskrives, hvordan avlen af racehunde og -katte er organiseret. Dernæst gøres der rede for de dyrevelfærdsmæssige konsekvenser heraf...... sundhed. Disse virkninger bunder for det første i såkaldt overtypning, for det andet i en øget forekomst af arvelige sygdomme, som ikke er direkte relateret til de avlsmål, der forfølges, og for det tredje i avlsrelaterede adfærdsproblemer. Efter at der er gjort rede for forekomsten af dyrevelfærdsmæssige...

  15. Edb-program optimerer nettilslutning af motorstyring

    DEFF Research Database (Denmark)

    Hansen, Steffan; Asiminoaei, Lucian; Blaabjerg, Frede

    2004-01-01

    er der også et forøget behov for at beregne konsekvenserne på nettet i form af harmoniske strømme og spændinger. Danfoss har i mange år haft muligheden for at tilbyde beregninger til kunderne og deres anlæg, men efterhånden var behovet for nøjagtige og kundetilpassede beregninger evt. i form af...

  16. Evaluering af IKT-forsøgsbyggeri

    DEFF Research Database (Denmark)

    Clausen, L.; Beim, A.

    2001-01-01

    Artiklen gennemgår en evaluering af et forsøgsbyggeri i Ringsted som har indbyggede IKT-løsninger. Dette med henbilk på hjemmearbejdspladser for handicappede beboere.......Artiklen gennemgår en evaluering af et forsøgsbyggeri i Ringsted som har indbyggede IKT-løsninger. Dette med henbilk på hjemmearbejdspladser for handicappede beboere....

  17. Please change your AFS/Linux Passwords

    CERN Multimedia

    2003-01-01

    Following some serious computer break-ins, which have exposed a number of passwords, users of AFS and Linux systems, including LXPLUS, are requested to change passwords as soon as possible. This especially concerns passwords typed at CERN, as well as any typed at remote sites while connected through CERN, since 18 March 2003. Use 'kpasswd' to change your AFS passwords. Further password advice is at: http://cern.ch/security/passwords Denise Heagerty, CERN Computer Security Officer, Computer.Security@cern.ch

  18. Undervisning med brug af struktureret gruppearbejde

    DEFF Research Database (Denmark)

    Andersen, Frans Ørsted

    2011-01-01

    Introduktion til undervisningspraksis baseret på Cooperative Learning og tilsvarende forståelser af struktureret gruppearbejde. Artiklen tager udgangspunkt i følgeforskning og pædagogisk udviklingsarbejde på Petersmindeskolen i Vejle.......Introduktion til undervisningspraksis baseret på Cooperative Learning og tilsvarende forståelser af struktureret gruppearbejde. Artiklen tager udgangspunkt i følgeforskning og pædagogisk udviklingsarbejde på Petersmindeskolen i Vejle....

  19. Anmeldelse af Because digital writing matters

    DEFF Research Database (Denmark)

    Brok, Lene Storgaard

    2014-01-01

    Digitale teknologier gør en forskel på skriftlig formidling. Anmelselse af Because digital writing matters, Danielle Nicole Devoss, Elyse Eidman Aadahl and Troy Hicks, The National Writing Project, San Fransisco, 2010.......Digitale teknologier gør en forskel på skriftlig formidling. Anmelselse af Because digital writing matters, Danielle Nicole Devoss, Elyse Eidman Aadahl and Troy Hicks, The National Writing Project, San Fransisco, 2010....

  20. OLM dispersion calculations based on 10 years' meteorology in relation to the Danish Air Quality Guideline; OML-spredningsberegninger paa basis af 10 aars meteorologi i relation til Luftvejledningen

    Energy Technology Data Exchange (ETDEWEB)

    Loefstroem, P.; Roerdam Olesen, H.

    2008-12-15

    In the Danish Air Quality Guideline (Luftvejledningen) the Danish Environmental Protection Agency recommends that the OML atmospheric dispersion model is used for compliance checking for industrial facilities. The current procedure to compare concentration levels with the limit value is based on the use of one years' worth of meteorological data. In order to obtain a better statistically founded basis for assessing the level of air pollution, the present study examines how the current use of one year of meteorological data can be extended to 10 years. The current use of only one year of data occasionally causes problems in the interpretation of the geographical distributions of the concentration levels. That is because different levels in different directions from the source might be due to random meteorological conditions, or due to the source configuration. The procedure is based on the statistical parameter known as the maximum monthly 99-percentile for one meteorological year (Kastrup Airport 1976). The present study uses 10 years of meteorological data from two Danish airports in Kastrup and AAlborg. These data are used for dispersion calculations for different types of point sources with varying stack heights, plume rise and possible nearby buildings. In order to obtain a new statistical parameter for the exposure - that corresponds to the current level of the maximum monthly 99-percentile and can be compared to the C-value ('limit value') of the Guideline the new statistics are based on the 120 monthly 99-percentiles for the 10 years of calculations. The 99-percentiles are ranked, and selected statistics are assessed, e.g. the maximum of all monthly 99-percentiles, the 4th highest monthly 99-percentile, the 8th highest monthly 99-percentile, the 12th highest monthly 99-percentile, and the average monthly 99-percentile. The study recommends that in future assessments the statistical parameter to be compared with the C-value of the Guideline is

  1. Blended Learning Analytics Model for Evaluation (BLAME). Et case-studie af universitetsunderviseres brug af Blackboard

    DEFF Research Database (Denmark)

    Musaeus, Peter; Bennedsen, Andreas Brændstrup; Hansen, Janne Saltoft;

    2015-01-01

    I denne artikel vil vi præsentere en strategi til inddragelse af læringsanalytik (learning analytics) ved evaluering af universitetsunderviseres brug af et nyt LMS på Aarhus Universitet: Blackboard. Vi diskuterer en model (BLAME: Blended Learning Analytics Model of Evaluation) for, hvordan...... kategorisering af kurser og data om læringsanalytik indsamlet på Blackboard kan integreres. Endvidere belyser vi, hvilke implikationer en sådan læringsanalytik kan have for blended learning ved at analysere to forskellige uddannelses-cases/illustrationer. Dernæst diskuterer vi pædagogisk udvikling i forbindelse...

  2. Epichlorhydrin og bisphenol A i mat-kontaktmaterialer af epoxylakeret metal og/eller af plast

    OpenAIRE

    Petersen, Jens Højslev; Pedersen, Gitte Alsing; Foverskov, Annie; Cederberg, Tommy Licht

    2013-01-01

    Det er ikke længere tilladt af bruge bisphenol A baseret polycarbonatplast til fremstilling af tåteflasker. Mattilsynet udtog i vinteren 2012/2013 7 typer af sutteflasker som blev kontrolleret for om de indeholdt polycarbonatbaserede plastdele. I alt 28 enkeltdele blev kontrolleret ved infrarød spektrometri. Herudover blev 6 tutekopper, bestående af 38 enkeltdele, analyseret med samme teknik. Der blev ikke påvist bisphenol A baseret plast ved analyserne. Dåser, bægre, tuber og skruelåg kan væ...

  3. STBC AF relay for unmanned aircraft system

    Science.gov (United States)

    Adachi, Fumiyuki; Miyazaki, Hiroyuki; Endo, Chikara

    2015-01-01

    If a large scale disaster similar to the Great East Japan Earthquake 2011 happens, some areas may be isolated from the communications network. Recently, unmanned aircraft system (UAS) based wireless relay communication has been attracting much attention since it is able to quickly re-establish the connection between isolated areas and the network. However, the channel between ground station (GS) and unmanned aircraft (UA) is unreliable due to UA's swing motion and as consequence, the relay communication quality degrades. In this paper, we introduce space-time block coded (STBC) amplify-and-forward (AF) relay for UAS based wireless relay communication to improve relay communication quality. A group of UAs forms single frequency network (SFN) to perform STBC-AF cooperative relay. In STBC-AF relay, only conjugate operation, block exchange and amplifying are required at UAs. Therefore, STBC-AF relay improves the relay communication quality while alleviating the complexity problem at UAs. It is shown by computer simulation that STBC-AF relay can achieve better throughput performance than conventional AF relay.

  4. Enzymatisk omestring til produktion af biodiesel

    DEFF Research Database (Denmark)

    Fjerbæk, Lene

    2007-01-01

      Biodiesel er i dag sammen med bioethanol et bud på, hvordan transportsektoren kan nedbringe sin netto CO2-emission til atmosfæren og lagrene af fossilt brændstof kan strækkes. På verdensplan forventes der en produktion af biodiesel på 7,9 mio. tons i 2007. Ved den industrielle fremstilling af...... biodiesel benyttes i dag kemiske katalysatorer såsom H2SO4, NaOH, MeONa eller KOH, der efterfølgende fjernes fra den producerede biodiesel med store mængder vand og derved produceres store mængder spildevand. Ved at benytte enzymer i processen kan man reducere mængden af spildevand, der skal renses. Enzymer...... benyttes ikke i de eksisterende processer, men det forventes, at udviklingen af processerne vil øge deres anvendelse i biodieselproduktion. I artiklen præsenteres fordele og ulemper ved anvendelse af enzymer til biodiesel produktion....

  5. Pædagogisk brug af test

    DEFF Research Database (Denmark)

    Nordenbo, Sven Erik; Allerup, Peter; Andersen, Hanne Leth;

    Publikationen er resultatet af et systematisk review foretaget i regi af Dansk Clearinghouse for Uddannelsesforskning. Reviewets grundspørgsmål er: Hvordan kan grundskolelæreres individ- og klassecentrerede brug af data fra test forbedre læreres didaktiske og/eller fagdidaktiske tiltag i klasser...... med almindelige elever? Spørgsmålet vedrører alene testtyper, som indgår i nationale test i de nordiske lande. Og hvordan indvirker indførelsen af testning på læreres didaktiske beslutninger og elevers læringsadfærd? Vi fandt frem til at grundskolelæreres individ- og klassecentrerede brug af testdata...... i klasser med almindelige elever forbedres, når de didaktiske og/eller fagdidaktiske tiltag bygger på test, som lærerne oplever et medejerskab for. Vi fandt fremtil, at introduktion af test fra instanser over klasseniveau med det formål at indvirke på undervisning og elevers læringsadfærd har...

  6. Bevarelse af biodiversiteten i de danske skove

    DEFF Research Database (Denmark)

    Højgård Petersen, Anders; Lundhede, Thomas; Bruun, Hans Henrik; Heilmann-Clausen, Jacob; Thorsen, Bo Jellesmark; Rahbek, Carsten; Strange, Niels

    2016-01-01

    areal på mindst 75.000 ha løvskov uden forstlig drift vil gøre en afgørende forskel for biodiversiteten. Et netværk af urørt løvskov af denne størrelsesorden, placeret ud fra kendskab til arternes udbredelse, er nødvendigt for at sikre hovedparten af den skovlevende biodiversitet i Danmark på lang sigt....... En indsats i statsskovene kan ikke stå alene. En stor del af den skovlevende biodiversitet findes kun i områder med meget lidt statsskov. Derfor er en betydelig indsats i private skove nødvendig. I det udpegede biodiversitetsnetværk på 75.000 ha er ca. 22.000 ha statsskov svarende til ca. 20 % af det...... samlede statsskovareal. Differentierede driftsmål for skovene kan sikre både biodiversiteten og skovens andre samfundsgoder. Størstedelen af det udpegede biodiversitetsnetværk er ikke sammenfaldende med de vigtigste områder for de øvrige samfundsgoder, hvilket reducerer eventuelle konflikter. På de...

  7. Effect of X irradiation on optical properties of Teflon-AF

    International Nuclear Information System (INIS)

    Radiation effects in optical-grade amorphous fluoropolymer, Teflon-AF, is investigated by UV-visible absorption and electron spin resonance (ESR) measurements. When irradiated with low-energy (40 kVP) X-rays at room temperature in air, Teflon-AF is found to develop a broad, structureless UV-absorption band in the wavelength interval 200-350 nm. While the UV absorption increases as a function of X-ray dose in Teflon-AF 1600 (Teflon-AF 2400), its optical transparency for a given dose of 67.5 kGy, however, remains unaffected. Additional measurements conducted using electron spin resonance (ESR) technique reveal that the observed UV absorption is caused by the X-ray induced peroxy radical (POO.). The results also suggest that the inclusion of dioxole monomer in the PTFE chain not only improves the optical clarity of Teflon-AF, as reported, but also increases its radiation tolerance. During a post-irradiation storage in air at RT for about 30 days the peroxy radical is observed to decay, with a concomitant decrease in UV absorption. A tentative model is proposed to explain the radiation damage and recovery mechanisms. (Author)

  8. P-Fuzzy Sets(AF,AF)and its Applications%P-模糊集(AF,AF)及其应用

    Institute of Scientific and Technical Information of China (English)

    闫立梅; 徐凤生; 史开泉

    2011-01-01

    By introducing dynamic characteristics to finite ordinary set X, the ordinary set Xwas improved and P-sets (packet sets) was proposed. P-sets is a pair of sets composed of internal P-set XF (internal packet set XF) and outer P-set XF (outer packet set XF), or, (XF, XF) is P-sets. P-sets has dynamic characteristics, that is, internal P-set has internal dynamic characteristics and outer P-set has outer dynamic characteristics. P-sets (XF , XF) was introduced to fuzzy set A of L. A. Zadeh,the fuzzy set A of L. A. Zadeh was improved,P-fuzzy sets(packet fuzzy sets) was given. P-fuzzy sets is a pair of fuzzy sets composed of internal P-fuzzy set AF (internal packet fuzzy set AF )and outer P-fuzzy set AF (outer packet fuzzy set AF) ,or, (AF ,AF) is P-fuzzy sets. P-fuzzy sets has dynamic characteristics, some properties and applications of P-fuzzy sets were given. Under certain conditions, P-fuzzy sets (AF ,AF)can come back to the original of ordinary fuzzy set A of L. A. Zadeh. P-fuzzy sets has more extensive applications than fuzzy set of L. A. Zadeh. P-fuzzy sets is a new direction of fuzzy set theory and applied research.%把动态特性引入到有限普通集合X内,改进了普通集合X,提出了P-集合(packet sets);P-集合是由内P-集合XF(internal packet set XF)与外P-集合XF(outer packet set XF)构成的集合对;或者(XF,XF)是P-集合.P-集合具有动态特性:内P-集合具有内-动态特性,外P-集合具有外-动态特性.把P-集合(XF,XF)引入到L.A.Zadeh模糊集A中,改进L.A.Zadeh模糊集A,提出P-模糊集(packet fuzzy sets).P-模糊集是由内P-模糊集AF(internal packet fuzzy setAF)与外P-模糊集AP(outer packet fuzzy set AF)构成的模糊集合对,或者(AF,AF)是P-模糊集.P-模糊集具有动态特性,给出了P-模糊集的若干特征与应用.在一定条件下,P-模糊集(AF,AF)能够回到L.A.Zadeh模糊集A的"原点".P-模糊集比L.A.Zadeh模糊集具有更大的应用空间.P-模糊集是模糊集理论与应用中的一个新的研究方向.

  9. Læring som improviseret udvikling af praksis

    DEFF Research Database (Denmark)

    Brinck, Lars

    2010-01-01

    Med afsæt i forfatterens fænomenografiske studie af amerikanske musikeres oplevelse af det at jamme diskuterer artiklen, hvorvidt jam-bandets spontant improviserende praksis kan give ny forståelse af rytmiske musikeres læring som et overordnet socialt fænomen. Ved at betragte jam-bandets praksis i...

  10. DVD anmeldelse - En Verden af Lyd og Musik

    DEFF Research Database (Denmark)

    Holck, Ulla

    2006-01-01

    Anmeldelse af DVD-udgivelse af Claus Bang (2005): En Verden af Lyd og Musik. Musikterapi for døve, hørehæmmede og multihandicappede børn og unge. Al tale med undertekst eller tegnsprogstolkning. DVD-boks med 3 stk. dobbeltlag DVD beregnet til afspilning på PC. Udgivet af Musikterapi-foreningen En...

  11. Kommentarer til love og ændringer af love

    DEFF Research Database (Denmark)

    Møgelvang-Hansen, Peter

    2002-01-01

    folkeoplysende foreningsarbejde og Folkeuniversitetet (folkeoplysningsloven) og ophævelse af lov om daghøjskoler m.v. og lov om den fri ungdomduddannelse samt ændring af lov om refusion af udgifter til uddannelse i forbindelse med aktivering m.m. samt ændring af forskellige love (Reform for daghøjskolerne...

  12. Computeren som medskaber af form – og praksis

    DEFF Research Database (Denmark)

    Elkær, Tim Nøhr

    2015-01-01

    projekter realiseret i Danmark som "Den Blå Planet" af 3XN (2013) og i projekter udarbejdet af danske arkitektvirksomheder i udlandet som: "Assar Children's Discovery Centre" af Henning Larsen Architects (2013) og "West 57'th Street" af BIG (2014). Denne afhandling undersøger mulighederne, som designere får...

  13. Ekstraktion af aromastoffer fra tørret oregano

    DEFF Research Database (Denmark)

    Christensen, Knud; Jakobsen, Jens Ellitsgård; Christensen, Jens Porskjær

    2007-01-01

    Ligevægtsforhold omkring ekstraktion af aktivstoffer fra oregano vulgaris med ethanol og vand er undersøgt med henblik på industriel fremstilling af tinkturer er undersøgt. Væskeoptag i tørret oregano som funktion af væskesammensætning er bestemt. Sammensætningen af aktivstoffer i ekstraktet som...

  14. Udvikling af informationskompetence i problemorienterede læreprocesser

    DEFF Research Database (Denmark)

    Birch Andreasen, Lars; Jørgensen, Lars; Nielsen, Jørgen Lerche

    begreberne om problemorienteret projektarbejde og informationskompetence i forhold til forståelsen af læring og af sammenhængen mellem information og viden. Og artiklen peger på betydningen af relationer og oplevelsen af relevans for at skabe sammenhæng mellem bibliotekers og uddannelsers praksis. Artiklen...

  15. Miljørigtig ombygning af Mallinggård

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2002-01-01

    Resume af rapport om den byggetekniske anvendelse af alternativ isolering ved en ombygning af Mallinggårds lade til undervisningslokaler, udarbejdet af Bent Møller fra Rudolf Steiner Skolen i Skanderborg under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  16. Katalytisk syntese af langkædede alkoholer fra syntesegas

    DEFF Research Database (Denmark)

    Christensen, Jakob Munkholt

    Populært dansk resume af ph.d.-afhandling - Katalytisk syntese af langkædede alkoholer fra syntesesgas.......Populært dansk resume af ph.d.-afhandling - Katalytisk syntese af langkædede alkoholer fra syntesesgas....

  17. Electromagnetic Interference Analysis and Suppression Measures of Air Compression Station Control System%空压机站控制系统电磁干扰分析及抑制措施

    Institute of Scientific and Technical Information of China (English)

    黄军东; 王林

    2012-01-01

    The problems of air compression station include electromagnetic interference,PC crashed and equipment faults,which affect normal production.The electromagnetic interference principle and suppression measures are analyzed.The relevant reasons are analyzed combined electromagnetic interference with the air compressor controller crash or damage and the improvement measures are proposed.%针对空压机站控制系统受电磁干扰而引起死机或设备故障,影响正常生产的问题,分析了电磁干扰机理及抑制措施,结合空压机控制器电磁干扰引起死机甚至损坏的故障,进行相应原因分析,并提出改进措施。

  18. Pressurized air supply device

    International Nuclear Information System (INIS)

    Ventilation air-conditioning facilities in a nuclear reactor building are adapted to suck clean external air not containing radioactivity through air supply filters disposed at an air intake port of the nuclear reactor building by means of an air supply blower and then supply the sucked air through an air supply duct and an air supply port to the inside of the power plant. Futher, pipeways for supplying sucked air to a compressor is branched from the air supply duct, through which air is supplied to an air compressor for instrumentation and an air compressor used in the power plant. The air sucked and compressed in the air compressor for instrumentation is further supplied by way of pipeways for supplying air for instrumentation to air-actuated valves, instruments, etc. Further, air sucked and compressed in the air compressor used in the power plant is further supplied by way of air supply pipeways for the power plant to a reservoir, air mask, etc. By supplying clean compressed air in this way, operators exposure dose can be reduced. (T.M.)

  19. Rationalerne bag de geografiske placeringer af vidensbaserede virksomheder i Danmark

    OpenAIRE

    Smith, Miriam Lerkenfeld; Jensen, Jon Gudmann; Jensen, Maria Nymann; Nielsen, Ann Cecilie; Fabech, Maja Yoon

    2006-01-01

    Projektet handler om danske vidensvirksomheders rationaler bag den geografiske placering af disses afdelinger i Danmark. Dette belyses af to teorier, omhandlende den kreative klasse og kompetenceklynger, udarbejdet af henholdsvis Richard Florida og Michael Porter begge amerikanske teoretikere. Med et udgangspunkt i den kritiske realisme foretages selvstændigt bearbejdelse af allerede eksisterende empirisk materiale, i form af to rapporter der behandler den kreative klasses geografiske placeri...

  20. Opportunistic Relay Selection in Multicast Relay Networks using Compressive Sensing

    KAUST Repository

    Elkhalil, Khalil

    2014-12-01

    Relay selection is a simple technique that achieves spatial diversity in cooperative relay networks. However, for relay selection algorithms to make a selection decision, channel state information (CSI) from all cooperating relays is usually required at a central node. This requirement poses two important challenges. Firstly, CSI acquisition generates a great deal of feedback overhead (air-time) that could result in significant transmission delays. Secondly, the fed back channel information is usually corrupted by additive noise. This could lead to transmission outages if the central node selects the set of cooperating relays based on inaccurate feedback information. In this paper, we introduce a limited feedback relay selection algorithm for a multicast relay network. The proposed algorithm exploits the theory of compressive sensing to first obtain the identity of the “strong” relays with limited feedback. Following that, the CSI of the selected relays is estimated using linear minimum mean square error estimation. To minimize the effect of noise on the fed back CSI, we introduce a back-off strategy that optimally backs-off on the noisy estimated CSI. For a fixed group size, we provide closed form expressions for the scaling law of the maximum equivalent SNR for both Decode and Forward (DF) and Amplify and Forward (AF) cases. Numerical results show that the proposed algorithm drastically reduces the feedback air-time and achieves a rate close to that obtained by selection algorithms with dedicated error-free feedback channels.

  1. For bestemmelse af drivhusgasudledning ved udtagning/Ekstensivering af landbrugsjorder på kulstofrige lavbundsjorder

    DEFF Research Database (Denmark)

    Gyldenkærne, Steen; Greve, Mogens Humlekrog

    Sammenfatning: Rapporten beskriver hvordan man kan beregne ændringen i drivhusgasemissionen ved omlægning af landbrugsjord til naturarealer. Rapporten er primært rettet mod tilskudsordningen vedr. udtagning af organiske lavbundsjorde, men kan også anvendes i andre sammenhænge. Rapporten anvender ...

  2. National monitorering af diabetesforekomst på basis af administrative sundhedsregistre

    DEFF Research Database (Denmark)

    Kristensen, Jette Kolding; Green, Anders; Carstensen, Bendix;

    2005-01-01

      Introduktion: Regeringens Diabeteshandlingsplan anbefalede i 2003 at etablere en national diabetes database med henblik på monitorering af diabetesforekomsten og kvalitetsudvikling. Formålet med denne undersøgelse er at validere en national algoritme til identifikation af erkendt diabetes og sa...

  3. 金属矿山井下压风自救系统参数设计%Design of Parameter Compressed-air Self-help System in Metal Mine

    Institute of Scientific and Technical Information of China (English)

    李磊; 黄园月; 宝海忠

    2012-01-01

    In order to improve the construction of six old systems,according to the safety administration issued a forced air self-rescue system specification,combination of X iadian gold mine pressure wind construction actual situation,the mine ventilation and fluid machinery pipeline for check,analysis of wind pressure and air volume,the downhole pressure wind pipeline reasonable parameters were obtained. According to the actual situation of underground mining set the compressed-air self-help system,forced air self-rescue system for underground personnel in distress was perfected. And it provides effective protection for survivors in emergency.%为了完善六大系统建设,根据安监总局下发的压风自救系统规范,结合夏甸金矿井下压风建设实际情况,利用矿井通风和流体机械对管路进行计算校验,分析压风能力和风量需求,得出井下压风管路合理参数,并根据井下开采的实际情况设置压风自救装置,完善了其压风自救系统,为井下遇难人员紧急避险提供了有效的生存保障.

  4. Hvad er kvalitet af svinekød? Resultater af en kvalitativ undersøgelse

    DEFF Research Database (Denmark)

    Bredahl, Lone; Andersson, Marchen

    1998-01-01

    at indikere god kvalitet. Desuden skulle undersøgelsen give information om, hvad forbrugerne forbinder med god kvalitet af svinekød, samt give indikation af, hvordan forbrugernes kvalitetsopfattelse relaterer sig til svinekøds fysiologiske karakteristika. Undersøgelsen blev gennemført som en...... fokusgruppediskussion med tyske forbrugere, hvor rigtige kødprøver blev anvendt som stimuli, mens der sideløbende blev foretaget tekniske målinger af kødkvaliteten. Det teoretiske udgangspunkt for undersøgelsen er sammenfattet i Total Food Quality-modellen, der beskriver, hvordan forbrugernes opfattelse af kvalitet af...... fødevarer hænger sammen med købsintentioner og mere objektive kriterier for fødevarekvalitet (Grunert, Hartvig Larsen, Madsen & Baadsgaard, 1996). Total Food Quality-modellen skelner eksplicit mellem kvalitetsforventninger og erfaret kvalitet. Udgangspunktet er, at forbrugerne danner kvalitetsforventninger...

  5. Merværdien af LEADER

    DEFF Research Database (Denmark)

    Thuesen, Annette Aagaard; Nielsen, Niels Christian

    Formålet med anvendelse af LEADER-metoden er at sikre, at der tildeles midler til lokale projekter på en sådan måde, at de baserer sig på lokale strategier, vurderinger og hvad der efterspørges lokalt. I Danmark er der 57 lokale aktionsgrupper (LAG’er), sammenslutninger med foreningsstruktur der...... analyse af hvordan og i hvilket omfang fem danske LAG’er arbejder efter LEADER-principperne. Anvendelse af LEADER-metoden forudsætter dog, at den lokale udvikling sker ud fra en vedtaget strategi og i et lokalt offentligt-privat partnerskab – i et samarbejde, der kan tænke på tværs af interesser og skabe...... netværk og nye samarbejdsrelationer. Der bliver imidlertid stadig stillet spørgsmål til metodens effektivitet i forhold til jobskabelse og økonomisk udvikling. Derfor efterspørges der fra flere sider indikatorer for hvorvidt og hvordan anvendelsen af LEADER bidrager eller giver ekstra værdi til programmer...

  6. [Compression material].

    Science.gov (United States)

    Perceau, Géraldine; Faure, Christine

    2012-01-01

    The compression of a venous ulcer is carried out with the use of bandages, and for less exudative ulcers, with socks, stockings or tights. The system of bandages is complex. Different forms of extension and therefore different types of models exist. PMID:22489428

  7. Wellhead compression

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Joe [Sertco Industries, Inc., Okemah, OK (United States); Vazquez, Daniel [Hoerbiger Service Latin America Inc., Deerfield Beach, FL (United States); Jacobs, Denis Richard [Hoerbiger do Brasil Industria de Equipamentos, Cajamar, SP (Brazil)

    2012-07-01

    Over time, all wells experience a natural decline in oil and gas production. In gas wells, the major problems are liquid loading and low downhole differential pressures which negatively impact total gas production. As a form of artificial lift, wellhead compressors help reduce the tubing pressure resulting in gas velocities above the critical velocity needed to surface water, oil and condensate regaining lost production and increasing recoverable reserves. Best results come from reservoirs with high porosity, high permeability, high initial flow rates, low decline rates and high total cumulative production. In oil wells, excessive annulus gas pressure tends to inhibit both oil and gas production. Wellhead compression packages can provide a cost effective solution to these problems by reducing the system pressure in the tubing or annulus, allowing for an immediate increase in production rates. Wells furthest from the gathering compressor typically benefit the most from wellhead compression due to system pressure drops. Downstream compressors also benefit from higher suction pressures reducing overall compression horsepower requirements. Special care must be taken in selecting the best equipment for these applications. The successful implementation of wellhead compression from an economical standpoint hinges on the testing, installation and operation of the equipment. Key challenges and suggested equipment features designed to combat those challenges and successful case histories throughout Latin America are discussed below.(author)

  8. Evaluering af politisk-administrative reformer

    DEFF Research Database (Denmark)

    Breidahl, Karen Nielsen; Gjelstrup, Gunnar; Hansen, Morten Balle;

    2015-01-01

    To af de største politisk-administrative reformer i Norden i 2000erne var reformen af arbejds- og velfærdsadministrationen i Norge (NAV-reformen) og kommunalreformen i Danmark. De to reformer har en række kendetegn til fælles – også med andre store politisk-administrative reformer. De blev vedtaget...... centrale og berørte såvel central- som lokal- og regional administration. Sidst men ikke mindst er begge reformer blevet evalueret, hvilket internationale undersøgelser har peget på har været undtagelsen snarere end reglen for reformer af denne karakter. Det er derfor interessant at analysere de to...

  9. E1AF degradation by a ubiquitin-proteasome pathway

    International Nuclear Information System (INIS)

    E1AF is a member of the ETS family of transcription factors. In mammary tumors, overexpression of E1AF is associated with tumorigenesis, but E1AF protein has hardly been detected and its degradation mechanism is not yet clear. Here we show that E1AF protein is stabilized by treatment with the 26S protease inhibitor MG132. We found that E1AF was modified by ubiquitin through the C-terminal region and ubiquitinated E1AF aggregated in nuclear dots, and that the inhibition of proteasome-activated transcription from E1AF target promoters. These results suggest that E1AF is degraded via the ubiquitin-proteasome pathway, which has some effect on E1AF function

  10. LCA af Biovækst

    OpenAIRE

    Møller, Jacob

    2012-01-01

    DTU ha færdiggjort en rapport, der beskriver en LCA (livscyklusvurdering) af kildesorteret organisk dagrenovation på BioVækst, et kombineret biogas- og komposteringsanlægRapporten beskriver en livscyklusbaseret miljøvurdering vha. LCA modellen EASEWASTE, for to behandlingsmetoder for kildesorteret organisk dagrenovation (KOD).De to behandlingsmetoder er hhv. biologisk behandling med produktion af biogas og kompost på BioVækstanlægget og affaldsforbrænding på Vestforbrænding.

  11. Verifikation af optiske koordinatmålemaskiner

    DEFF Research Database (Denmark)

    Larsen, Erik

    Kalibrering af optiske måleudstyr kalibreres ofte på en måde der ikke er valgt hensigtsmæ ssig, set i forhold til de emner der efterfølgende måles på udstyret. Det er ofte ”de forhåndenvæ rende søms” metode der anvendes. Udviklingen af optiske måleudstyr går stæ rkt for tiden, og understøttes kra...

  12. Et studie af credit ratings for lande

    DEFF Research Database (Denmark)

    Hansen, Kenneth; Jensen, Anders Bønnelykke; Thomsen, Rene Østergaard

    Rapportens primære målgruppe er studerende ved de finansielle uddannelser, og forudsætter et vist kendskab til makroøkonomi og statistik. Den vil kunne læses af studerende på 3. semester på både finansøkonom- og finansbachelor-uddannelserne. I rapporten diskuteres og opdateres Cantor og Packers m...... model for forudsigelse/forståelse af landes credit ratings vha. makroøkonomiske størrelser. Den anvendte model er lineær regression....

  13. En kvantitativ analyse af danskernes huskesedler

    OpenAIRE

    Schmidt, Marcus

    2005-01-01

    Den foreliggende rapport bygger på en analyse af 871 huskesedler. Sedlerne er dels indsamlet i Jylland og dels i København. Indsamlingen af forbrugernes kasserede huskesedler er foregået såvel inde i dagligvarebutikkerne (indkøbskurve, affaldsspande) som ude foran butikkerne (parkeringsplads, indkøbsvogne). Dataindsamlingen omfatter de største supermarkeder og discountbutikker samt Bilka. Det vedhæftede appendiks forenden indeholder en nærmere redegørelse for den anvendte metodiske fremga...

  14. Den teoretiske udvikling af Supply Chain Strategimodeller

    DEFF Research Database (Denmark)

    Arvad Johansen, Jens

    2011-01-01

    segmentering via postponement-princippet, har givet mærkbare forbedringer. Det beskrives endvidere, hvordan produkternes livscyklus påvirker valget af supply chain design. Begrebet Demand Chain Management( DCM), hvormed strategimodeller bruger klassiske marketingelementer sammen med Supply Chain Management......Denne artikel beskriver med udgangspunkt i artikler og virksomhedseksempler udviklingen inde for supply chain strategimodeller. Ved hjælp af tidligere udviklede koncepter besvares spørgsmålet: “Hvad er den rette supply chain for mine produkter?”. Virksomhedseksempler beskriver, hvordan supply chain...... (SCM), bliver behandlet og der udvikles en DCM-strategimodel....

  15. Analyse af vindklima ved Navitas Park

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Lauridsen, Thomas Bank

    Formålet med denne vindklimaanalyse er at afklare, hvorvidt opførelsen af Navitas Park på Århus Havn vil medføre uhensigtsmæssige eller farlige vindforhold for fodgængere i området omkring bygningen.......Formålet med denne vindklimaanalyse er at afklare, hvorvidt opførelsen af Navitas Park på Århus Havn vil medføre uhensigtsmæssige eller farlige vindforhold for fodgængere i området omkring bygningen....

  16. Leagile Manufacturing - implementering af modulariserede produktplatforme

    DEFF Research Database (Denmark)

    Bjarnø, Ole-Christian

    2003-01-01

    Lean og Agile (Leagile) Manufacturing indebærer ikke blot den rette balance (dekobling) mellem lean producerede komponenter og agile konfigurerede færdigvarer, og dermed til levering af individualiserede produkter til konkurrencedygtige priser og høj kvalitet, men også til effektivitet og...... fleksibilitet i produktudvikling og produktion. For at opnå integrationen mellem agile og lean kan der arbejdes med en vifte af integrationsmekanismer inden for organisatoriske og teknologiske virkemidler. Projektet har til formål at identificere, strukturere og modellere de centrale analyse- og...

  17. Effekt af døgnregulering af jagt på gæs

    DEFF Research Database (Denmark)

    Madsen, J.; Jørgensen, H. E.; Hansen, F.

    I henhold til Miljø- og Energiministeriets bekendtgørelse om jagttider er jagt på gæs pr. 1. september 1994 kun tilladt i tidsrummet 1½ time før solopgang til kl. 10 om formiddagen; fra 1. september 1997 blev jagttiden ændret fra kl. 10 til kl. 11. Formålet med indførelsen af døgnreguleringen var...... at give de efterårsrastende gæs bedre muligheder for uforstyrret at søge føde i dagtimerne og dermed medvirke til at gæssene opholdt sig i længere tid på de danske rastepladser. I samarbejde med Skov- og Naturstyrelsen har DMU i efterårene 1994-1997 undersøgt effekten af døgnreguleringen af gåsejagt...... på gæssenes brug af de danske rastepladser og på jagtudbyttet af gæs i Danmark. Undersøgelsen har fokuseret på grågås og kortnæbbet gås, med supplerende data på canadagås. Indførelsen af døgnregulering af gåsejagt siden 1994 gav ikke anledning til et påviseligt større antal efterårsrastende gæs på de...

  18. EPA Facility Registry Service (FRS): AIRS_AFS

    Data.gov (United States)

    U.S. Environmental Protection Agency — This web feature service contains location and facility identification information from EPA's Facility Registry Service (FRS) for the subset of facilities that link...

  19. EPA Facility Registry Service (FRS): AIRS_AFS_MAJOR

    Data.gov (United States)

    U.S. Environmental Protection Agency — This web feature service contains location and facility identification information from EPA's Facility Registry Service (FRS) for the subset of facilities that link...

  20. Undersøgelsen af brugernes evaluering af kontorpakker på Århus Sygehus og i Psykiatrien i Århus

    DEFF Research Database (Denmark)

    Hørlück, Jens

    En analyse af brugernes opfattelse af kvaliteten af tre office pakker: MS Office 2003 / 2007 og OpenOffice.  ......En analyse af brugernes opfattelse af kvaliteten af tre office pakker: MS Office 2003 / 2007 og OpenOffice.  ...

  1. Simulering af ændret publikumsbelastning i Mols Bjerge

    DEFF Research Database (Denmark)

    Skov-Petersen, Hans; Foged, Mette

    2010-01-01

    Det kan være svært at forudse, hvad effekten af ændringer i adgangsforholdene til et naturområde vil blive. Dette Videnblad beskriver, hvordan en agent-baseret simuleringsmodel kan anvendes til vurdering af fremtiden ved flytning af en parkeringsplads ved trehøje i Mols Bjerge.......Det kan være svært at forudse, hvad effekten af ændringer i adgangsforholdene til et naturområde vil blive. Dette Videnblad beskriver, hvordan en agent-baseret simuleringsmodel kan anvendes til vurdering af fremtiden ved flytning af en parkeringsplads ved trehøje i Mols Bjerge....

  2. Incitamentet til pensionsopsparing set i lyset af de nye regler for beskatning af pensionsafkast

    OpenAIRE

    Guldager, Peter

    2000-01-01

    I forbindelse med FL2001 er der vedtaget en række love, som får betydning for valget mellem aktier og obligationer i en pensionsordning og i et frit depot. Ændringerne betyder, at afkast af aktier og obligationer i en kapitalpension fra 2001 bliver genstand for den samme beskatning. Der er fortsat et incitament til at oprette, opretholde og indskyde på en kapitalpension. De gennemførte og foreslåede ændringer vil dog i løbet af perioden 2000-02 påvirke dette incitament afhængigt af, om kapita...

  3. Analyse af burst-fase fænomenet ved hydrolyse af cellulose

    OpenAIRE

    Olsson, Kim

    2009-01-01

    Dette projekt tager udgangspunkt i den ikke‐lineære kinetik der observeres i form af en burst‐fase i kalorimetriske forsøg, når cellulase‐systemer og β‐glucosidase samarbejder om at nedbryde forskellige cellulosiske substrater. Burstfasen ses i form af en høj varmeudvikling, der kort tid efter falder drastisk. I dette projekt blev følgende teorier, der kunne ligge til baggrund for den ikke‐lineære kinetik, undersøgt: 1. Uproduktiv og inhiberende binding af cellulase til cellulos...

  4. Cycle-by-cycle Variations in a Direct Injection Hydrogen Enriched Compressed Natural Gas Engine Employing EGR at Relative Air-Fuel Ratios.

    OpenAIRE

    Olalekan Wasiu Saheed; Rashid A.A.; Baharom Masri

    2014-01-01

    Since the pressure development in a combustion chamber is uniquely related to the combustion process, substantial variations in the combustion process on a cycle-by-cycle basis are occurring. To this end, an experimental study of cycle-by-cycle variation in a direct injection spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation at relative air-fuel ratios was conducted. The impacts of relative air-fuel ratios (i.e. λ = 1.0, 1.2, 1.3 and 1.4 whi...

  5. Degradation of AF1Q by chaperone-mediated autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng; Ji, Min; Lu, Fei; Zhang, Jingru [Department of Hematology, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan 250012 (China); Li, Huanjie; Cui, Taixing; Li Wang, Xing [Research Center for Cell Therapy, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan 250012 (China); Tang, Dongqi, E-mail: tangdq@sdu.edu.cn [Research Center for Cell Therapy, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan 250012 (China); Center for Stem Cell and Regenerative Medicine, The Second Hospital of Shandong University, Jinan 250033 (China); Ji, Chunyan, E-mail: jichunyan@sdu.edu.cn [Department of Hematology, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan 250012 (China)

    2014-09-10

    AF1Q, a mixed lineage leukemia gene fusion partner, is identified as a poor prognostic biomarker for pediatric acute myeloid leukemia (AML), adult AML with normal cytogenetic and adult myelodysplastic syndrome. AF1Q is highly regulated during hematopoietic progenitor differentiation and development but its regulatory mechanism has not been defined clearly. In the present study, we used pharmacological and genetic approaches to influence chaperone-mediated autophagy (CMA) and explored the degradation mechanism of AF1Q. Pharmacological inhibitors of lysosomal degradation, such as chloroquine, increased AF1Q levels, whereas activators of CMA, including 6-aminonicotinamide and nutrient starvation, decreased AF1Q levels. AF1Q interacts with HSPA8 and LAMP-2A, which are core components of the CMA machinery. Knockdown of HSPA8 or LAMP-2A increased AF1Q protein levels, whereas overexpression showed the opposite effect. Using an amino acid deletion AF1Q mutation plasmid, we identified that AF1Q had a KFERQ-like motif which was recognized by HSPA8 for CMA-dependent proteolysis. In conclusion, we demonstrate for the first time that AF1Q can be degraded in lysosomes by CMA. - Highlights: • Chaperone-mediated autophagy (CMA) is involved in the degradation of AF1Q. • Macroautophagy does not contribute to the AF1Q degradation. • AF1Q has a KFERQ-like motif that is recognized by CMA core components.

  6. Livsvalg konceptualiseret som dynamisk realisering af livsbaner

    DEFF Research Database (Denmark)

    Schnieber, Anette

    2009-01-01

    De valgsituationer, man i daglig tale kender som ”tilværelsens store valg”, mangler definition i den psykologiske litteratur, og det er således ikke klart, hvorvidt og evt. hvorledes disse valg adskiller sig fra andre typer. I artiklen gives en definition af ”de store valg”, og de adskilles fra...

  7. Dimensionering af naturlig ventilation ved termisk opdrift

    DEFF Research Database (Denmark)

    Terpager Andersen, K.

    Rapporten behandler et simpelt formelsæt til beregning af naturlig ventilation ved termisk opdrift. Der betragtes først det simple tilfælde med to åbninger og ensartet indetemperatur. Derefter vises, hvordan formelsættet kan udvides til også at omfatte rum med temperaturlagdeling og med åbninger ...

  8. Skal religion ud af det offentlige rum?

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2009-01-01

    I debatter om religion og politik fremsættes ofte generelle krav om "mindre religion i det offentlige rum", der tit begrundes med en henvisning til idealer om sekularisme, neutralitet eller upartiskhed. Artiklen skelner først mellem tre forskellige betydninger af, hvad der overordnet kan forstås...

  9. Implementering af ITIL® IT-governance

    DEFF Research Database (Denmark)

    Salling, Allan

    -forskningsproblem. ITIL-litteraturen anviser bl.a. Critical Success Factors (CSF) som en løsning. Baseret på et identificeret litteraturgap blev det besluttet at undersøge, om kendte CSF kunne løse problemet. På den baggrund er der gennemført et aktionsforskningsprojekt, hvor ITILimplementeringsproblemet søges løs ved...... hjælp af kendte CSF. Der blev udvalgt en egnet caseorganisation, og det blev besluttet at fokusere på ITILs Change Management proces. Et et stigende pres fra IT-revisionen medførte et behov for succesfuld ITIL-implementering, og IT-ledelsen var opsat på at løse dette problem ”én gang for alle......”. Aktionsforskningen gav (især) i begyndelsen positive resultater, og der kunne præsenteres handleanvisninger til forbedret operationalisering af CSF. Imidlertid opstod der problemer længere inde i forløbet. Det blev tydeligt, at selv de bedste CSF ikke kunne løse problemerne. En bredere afsøgning af teorien viste...

  10. LCA af Biovækst

    DEFF Research Database (Denmark)

    Møller, Jacob

    DTU ha færdiggjort en rapport, der beskriver en LCA (livscyklusvurdering) af kildesorteret organisk dagrenovation på BioVækst, et kombineret biogas- og komposteringsanlæg Rapporten beskriver en livscyklusbaseret miljøvurdering vha. LCA modellen EASEWASTE, for to behandlingsmetoder for kildesorteret...

  11. Udvikling af virksomhedens transformationssystem (produktions- og distributionssystemet)

    DEFF Research Database (Denmark)

    Pagh, Janus Dore

    Denne ph.d.-afhandling behandler emnet udvikling af den industrielle produktionsvirksomheds transformationssystem, der omfatter virksomhedens samlede produktions- og distributionssystem. Der er i de senere år komet stigende fokus på virksomhedernes evne til at skabe differentieret og kundetilpass...

  12. Brands som brikker i konstruktionen af identitet

    DEFF Research Database (Denmark)

    Hermansen, Judy

    2008-01-01

    Forbrug spiller en vigtig rolle i produktionen af mening og værdier, som kan skabe og vedligeholde både forbrugerens personlige og sociale verden - og derfor er reklame også en vigtig kilde til disse symbolske betydninger. Udgivelsesdato: juni...

  13. Om institutionalisering af børneopdragelse

    DEFF Research Database (Denmark)

    Gulløv, Eva

    2009-01-01

      Kapitlet beskæftiger sig med konsekvenser ved institutionsophold. Ikke de psykologiske konsekvenser, som institutionsophold kan have for det enkelte barn, men de mere kollektive implikationer ved, at børneopdragelse gennem de sidste 50 år er blevet et samfundsanliggende. Diskussionen består af ...

  14. Modellering, test og fortolkning af indirekte revisionsbeviser

    DEFF Research Database (Denmark)

    Holm, Claus

    vil være påvirket af kildens troværdighed og rapportens relevans. I dette indlæg vises, hvordan den normative teori bag den Bayesianske flertrinsmodel giver mulighed for at hypoteser kan udledes og testes. Et 2*2 eksperimentielt design er testet på 89 revisorer med tre hovedresultater, nemlig (1...

  15. Husker du? Nutidig genlyd af fortid

    DEFF Research Database (Denmark)

    Larsen, Charlotte Rørdam

    moderne nostalgi til længsel efter (for)tid. Min tese er, at lyden er en vigtig formidler af den forgangne tid, som de følgende analyserede filmserier fremstiller som positiv. Reklamefilmen kan ikke aktivere nærsansernes lugt og smag og dermed være den kilde til erindring, som Proust genoplevede – nemlig...

  16. Digitale leverancer ved aflevering af byggeri

    DEFF Research Database (Denmark)

    Bertelsen, Niels Haldor; Sørensen, Nils Lykke; Shaukat, Fatima

    forståelsesramme for digitale ydelser, byggeleverancer og informationer, som beskrives i seks faglige spor: Økonomi, marked/brugere, produkt/egenskaber, proces/aktører, informatik/bim og innovation/læring/benchmarking. Udredningen fremlægger forslag til fælles branchekoncept for bygherrens beskrivelse af digitale...

  17. Evaluering af elevernes personlige og sociale kompetencer

    DEFF Research Database (Denmark)

    Skov, Poul

    2003-01-01

    I artiklen beskrives forudsætninger og fremgangsmåder ved evaluering af elevernes personlige og sociale kompetencer. Det betones, at evalueringen ikke alene bør have fokus på eleverne, men i høj grad også på undervisningen....

  18. Hvad handler ledelse af videnarbejde om?

    DEFF Research Database (Denmark)

    Buch, Anders; Andersen, Vibeke

    2015-01-01

    Den amerikanske ledelses- og organisationsguru Peter F. Druckers begreb om videnarbejde og ledelse af videnarbejdet har på mange måder været definerende for moderne ledelsestænkning. I denne artikel argumenterer vi via en empirisk case for, at ledelse i videnarbejdet omfatter meget mere og andet ...

  19. Udvikling af medicinsk behandling mod bipolar lidelse

    DEFF Research Database (Denmark)

    Ellegaard, Pernille Kempel

    2015-01-01

    Selvom Esbjerg ligger i vandkants Danmark, er det den Psykiatriske Forskningsenhed i denne by, der er primus motor for et stort forsøg blandt mennesker, der lider af bipolar lidelse. Forsøget hedder ”NACOS”, og er et medicinsk forsøg til mennesker, der befinder sig i den depressive fase....

  20. Numerical Analysis of Autoignition and Combustion of n-Butane and Air Mixture in Homogeneous-Charge Compression-Ignition Engine Using Elementary Reactions

    Science.gov (United States)

    Yamasaki, Yudai; Iida, Norimasa

    The present study focuses on clarifying the combustion mechanism of the homogeneous-charge compression-ignition (HCCI) engine in order to control ignition and combustion as well as to reduce HC and CO emissions and to maintain high combustion efficiency by calculating the chemical kinetics of elementary reactions. For the calculations, n-butane was selected as fuel since it is a fuel with the smallest carbon number in the alkane family that shows two-stage autoignition (heat release with low-temperature reaction (LTR) and with high-temperature reaction (HTR)) similarly to higher hydrocarbons such as gasoline. The CHEMKIN code was used for the calculations assuming zero dimensions in the combustion chamber and adiabatic change. The results reveal the heat release mechanism of the LTR and HTR, the control factor of ignition timing and combustion speed, and the condition need to reduce HC and CO emissions and to maintain high combustion efficiency.

  1. Health Information in Somali (af Soomaali): MedlinePlus

    Science.gov (United States)

    ... Information Translations PET (Positron Emission Tomography) Scan Sawirka PET (Positron Emission Tomography) - af Soomaali (Somali) Bilingual PDF Health Information Translations Stress Muga Sawirka Qiimeynta Cadaadiska Nafsadda - af Soomaali (Somali) ...

  2. Iværksættelser af vanvid

    DEFF Research Database (Denmark)

    Lund, Jacob

    2013-01-01

    Anmeldelse af Maurice Blanchot, "Dagens vanvid" / "Mit dødsøjeblik" og Laura Riding, "En anonym bog"......Anmeldelse af Maurice Blanchot, "Dagens vanvid" / "Mit dødsøjeblik" og Laura Riding, "En anonym bog"...

  3. Vindstødsinducerede svingninger af afbarduneret antennemast

    DEFF Research Database (Denmark)

    Jacobsen, Leif; Svenningsen, Klaus Bukh

    Dette eksamensprojekt omhandler en teoretisk og praktisk bestemmelse af vindstødsinducerede svingninger af en afbarduneret antennemast. Antennemasten, der tilhører Post- og Telegrafsvæsnet, er beliggende i Frejlev syd for Aalborg....

  4. Epichlorhydrin og bisphenol A i mat-kontaktmaterialer af epoxylakeret metal og/eller af plast

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Pedersen, Gitte Alsing; Foverskov, Annie;

    50 enkeltdele fra disse prøver blev undersøgt ved infrarød spektrometri og 9 af prøverne viste tegn på at indeholde epoxylak. Disse prøver blev undersøgt ved en ”worst case” ekstraktionstest hvor der kunne påvises små indhold af bisphenol A i ekstrakterne mens der ikke kunne påvises epichlorhydrin...

  5. Vejledning af adjunkter - oplevelse af og betingelser for faglig pædagogisk vejledning

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2007-01-01

    Artiklen tilbyder en teoretisk og didaktisk refleksion over adjunkt-vejleder interaktion. På baggrund heraf konkluderes, at eventuelle vanskeligheder med at tolke præmisserne for interaktionen kan hænge sammen med, at interaktionen ofte udfolder sig inden for en dobbeltkodning. Didaktisk analyse ...... modsvarer de krav til didaktisk kompetence, som adjunkten står overfor. Artiklen afrundes med skitsering af strategier for henholdsvis opløsning og håndtering af de beskrevne modsætninger....

  6. Udvikling af en internetsøgestrategi til identifikation af ny medicinsk teknologi inden for prostatacancer

    DEFF Research Database (Denmark)

    Thygesen, Marianne; Vondeling, Hindrik; Douw, Karla

    2007-01-01

    internetsider efter efficiens. Her er efficiens forstået som mindst antal minutter brugt pr. fund af information om en ny væsentlig medicinsk teknologi. Resultater: Strategien består af ti sider, som bør benyttes i følgende rækkefølge: YahooHealth, DoctorsGuide, The National Electronic Library for Medicines...

  7. Tumor-heterogenitet: Betydning af klon-evolution under cancersygdomme

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    2013-01-01

    De senere års cancerforskning viser, at cellulær evolution er afgørende for forståelse af sygdomsudviklingen, og sandsynligvis også for fremtidig behandling af cancer hos dyr og mennesker.......De senere års cancerforskning viser, at cellulær evolution er afgørende for forståelse af sygdomsudviklingen, og sandsynligvis også for fremtidig behandling af cancer hos dyr og mennesker....

  8. Uddrag af Ph.d.-afhandlingen Den groteske modernisme

    DEFF Research Database (Denmark)

    Lübker, Henrik

    Om forholdet mellem "det groteske" og "den groteske modernisme" eksemplificeret i en læsning af E.A. Poes "The Fall of the House of Usher" og flere af Francis Bacons malerier.......Om forholdet mellem "det groteske" og "den groteske modernisme" eksemplificeret i en læsning af E.A. Poes "The Fall of the House of Usher" og flere af Francis Bacons malerier....

  9. Compressive beamforming

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Mosegaard, Klaus

    2014-01-01

    Sound source localization with sensor arrays involves the estimation of the direction-of-arrival (DOA) from a limited number of observations. Compressive sensing (CS) solves such underdetermined problems achieving sparsity, thus improved resolution, and can be solved efficiently with convex...... optimization. The DOA estimation problem is formulated in the CS framework and it is shown that CS has superior performance compared to traditional DOA estimation methods especially under challenging scenarios such as coherent arrivals and single-snapshot data. An offset and resolution analysis is performed to...

  10. Immediat indsættelse af enkelttandsimplantater i privat praksis

    DEFF Research Database (Denmark)

    Hartlev, Jens; Kohberg, Peter; Ahlmann, Søren;

    2015-01-01

    Immediat indsættelse af enkelttandsimplantater Formål – At vurdere behandlingsresultat og patienttilfredshed efter immediat indsættelse af enkelttandsimplantat og cementering af en provisorisk krone i samme behandlingsseance, hvor behandlingen var blevet foretaget i privat praksis. Materiale og m...

  11. Dimensionering af varme- og ventilationsanlæg til stalde

    DEFF Research Database (Denmark)

    Pedersen, J.

    Fra tid til anden har der været rejst kritik af de dimensioneringsregler vedrørende varme- og ventilationsanlæg i staldbygninger, som er udarbejdet af Statens Byggeforskningsinstitut. En af årsagerne hertil er måske, at der fra instituttets side ikke er gjort tilstrækkelig godt rede for, på hvilk...

  12. Analyse af friktionsforhold ved kold, halvvarm og varm formgivning

    DEFF Research Database (Denmark)

    Post-Pedersen, Bente

    Det foreliggende arbejde indeholder en gennemgang af state-of-the-art indenfor testning af friktionsforhold ved kold, halvvarm og varmformgivning. Principper og resultater for en række tribologiske teste er gennemgået. En kritisk vurdering af testenes anvendelse er foretaget. Der er gennemført en...

  13. Renovering af Skive Stadion : konsolideringsforsøg

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.

    I forbindelse med opgradering af Skive Stadion til Olympisk niveau, skal kunststofbanens fremtidige sætninger vurderes nærmere. Generelt er der på lokaliteten et 2-3 meter tykt sandfyldlag underlejret af postglaciale, marine gytje- og sandaflejringer. Undersiden af gytjeaflejringerne er i ca 9...

  14. To-eksponent formel til dimensionering af varmtvandsbeholdere

    DEFF Research Database (Denmark)

    Christensen, Niels Uhre

    2010-01-01

    Dette hæfte er udarbejdet i forbindelse med kurset BTINS3 ved Ingeniørhøjskolen i Århus. I kurset undervises studerende bl.a. i dimensionering af varmtvandsbeholdere ? herunder bestemmelse af afkølinger og beholderydelsens afhængighed af det dimensionerende temperatursæt. I undervisningen inddrages...

  15. Anmeldelse af: Afghantsy. The Russians in Afghanistan 1979-89

    DEFF Research Database (Denmark)

    Vestenskov, David

    2012-01-01

    Baseret på nyligt afklassificeret materiale fra arkiverne i Moskva samt fremstillinger af russiske historikere, tegnes et anderledes og mere nuanceret billede af de sovjetiske erfaringer fra Afghanistan. De første spadestik til opgøret med den amerikanske stempling af den sovjetiske ageren i jule...

  16. Ekstraktion af æteriske olier fra oregano

    DEFF Research Database (Denmark)

    Ellitsgaard Jakobsen, Jens; Ankerfeldt, Dorte; Jensen, Morten Busch

    med keratin - Ammoniakforurening reduceres med ny teknologi - Genvinding og genanvendelse af ammoniak fra spildevand og husdyrgødning - Ginseng - en virkningsfuld medicinplante - Ekstraktion af æteriske olier fra oregano "Biotek" er udviklet med udgangspunkt i originalartikler udarbejdet af forskere...

  17. Sætningsforhold og varmeledningsevne af alternative isoleringsmaterialer - litteraturstudie

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2001-01-01

    Resume af rapport, der præsenterer et litteraturstudie over metoder til undersøgelse af sætningsforhold og varmeledningsevne for alternative isoleringsmaterialer, udarbejdet af Teknologisk Institut og DELTA Akustik & Vibration under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig...... isolering"...

  18. Compressed convolution

    CERN Document Server

    Elsner, F

    2013-01-01

    We introduce the concept of compressed convolution, a technique to convolve a given data set with a large number of non-orthogonal kernels. In typical applications our technique drastically reduces the effective number of computations. The new method is applicable to convolutions with symmetric and asymmetric kernels and can be easily controlled for an optimal trade-off between speed and accuracy. It is based on linear compression of the collection of kernels into a small number of coefficients in an optimal eigenbasis. The final result can then be decompressed in constant time for each desired convolved output. The method is fully general and suitable for a wide variety of problems. We give explicit examples in the context of simulation challenges for upcoming multi-kilo-detector cosmic microwave background (CMB) missions. For a CMB experiment with O(10,000) detectors with similar beam properties, we demonstrate that the algorithm can decrease the costs of beam convolution by two to three orders of magnitude...

  19. Technical basis of compressed-air energy storage as a substitute for lead batteries; Techn. Grundlagen der Druckluftspeicherung und deren Einsatz als Ersatz fuer Bleibatterien

    Energy Technology Data Exchange (ETDEWEB)

    Cyphelly, I.; Brueckmann, Ph.; Menhardt, W.

    2004-07-01

    Stand-alone electrical grids need storage systems, as consumption and generation usually do not fit in time and magnitude; this paper shows typical rural revenue-generating dairy applications in the multi-kW-range: this allows for a detailed analysis of the lay-out, and also of the needed elements and of the types of voltages involved (230 V AC, 24 and 315 V DC), but also of the characteristics of the storage system. A list of wishful storage qualities is extracted from these experiences and used to evaluate a possible pneumatic substitute to the lead-acid battery (BOP = Batteries w. Oilhydraulics and Pneumatics) and to imagine an extension towards a higher power range (like grid quality enhancement in the MW-range). According to the state-of-the-art and the commercial availability of components which would be inserted in this storage chain, an overview of the two existing systems (BOP-A with compression/expansion directly in the storage vessel volume and BOP-B with external thermodynamics) is presented with formulae and graphics yielding main parameters (efficiency, specific energies etc) and sizing basics. This data compilation also helps to insert BOP technologies in the latest storage debate, where future distribution technology is at stake. (author)

  20. Studerende og underviseres brug af digitale medier - En kvantitativ undersøgelse af Aarhus Universitets studerende og underviseres brug af digitale medier og internettet anno 2008

    Directory of Open Access Journals (Sweden)

    Maria Hvid Stenalt

    2009-06-01

    • Hvilke medier anvender universitetsstuderende generelt? • Ligner undervisernes medievalg/forbrug de studerendes? • Hvilke medier inddrager underviserne i undervisningen? Nærværende artikel vil forsøge at besvare disse spørgsmål på baggrund af en kvantitativ spørgeskemaundersøgelse af Aarhus Universitets studerende og underviseres brug af digitale medier og internettet. Undersøgelsen blev gennemført i efteråret 2008 af E-læringsenheden ved Aarhus Universitet som led i en almen kvalitetssikring på media- og e-læringsområdet, samt som led i en behovsafklaring vedrørende etablering af et medie- og podcastarkiv. E-læringsenheden er en administrativ enhed, der teknisk og pædagogisk understøtter underviseres inddragelse af digitale medier i undervisningen.