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 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...

  4. 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...

  5. 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.

  6. 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:...

  7. 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.

  8. 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...

  9. 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.

  10. 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 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, an underground cavern is used as a pressure vessel for the storage of the compressed air. Both systems...... a turbine when discharging. In this case, the liquid works effectively as a piston compressing the gas in the vessel, hence the name “Adiabatic Liquid Piston Compressed Air Energy Storage” (ALP-CAES). The compression ratio of the gas in the vessel (ratio between maximum and minimum pressure) is relatively...

  11. Improve Compressed Air System Performance with AIRMaster+

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-05-01

    AIRMaster+ provides a systematic apporach for assessing the supply-side performance of compressed air systems. Using plant-specific data, the software effectively evaluates supply-side operational costs for various equipment configurations and system pro

  12. 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, ...

  13. 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.

  14. Compressibility of air in fibrous materials

    DEFF Research Database (Denmark)

    Tarnow, Viggo

    1996-01-01

    The dynamic compressibility of air in fibrous materials has been computed for two assumed configurations of fibers which are close to the geometry of real fiber materials. Models with parallel cylinders placed in a regular square lattice and placed randomly are treated. For these models...... the 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...

  15. 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

  16. 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...

  17. 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...

  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...... the prices from fluctuating to the extent that CAES investments have not been considered feasible. This report studies the effect of technological development and possible future price development of investments in CAES plants of various capacities. It is found that advanced high-efficiency CAES plants...

  20. 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.

  1. 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.

  2. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None, 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.

  3. Elimination of microorganisms from dental operatory compressed air.

    Science.gov (United States)

    De Ciccio, A; Chan, E C

    1998-01-01

    Compressed air is used to power high-speed handpieces, as well as to dry and clean surfaces in the oral cavity during patient treatment, in all dental operatories. The compressed air used in the dental operatories located in large institutions such as universities or hospitals is generally obtained from a central source, and is produced by continually running compressors. In operatories located in private practice settings, compressed air is obtained from small on-site air compressors, which may be run less frequently. A survey was made of operatories in the Montreal area to determine the microbial load of the compressed air produced by air compressors. An air sampler was used to collect compressed air and impinge it on a rotating agar medium surface. Compared to the air produced from compressors in constant use, the air collected from compressors that ran intermittently had a very high microbial load. The efficacy of an apparatus designed to sterilize the contaminated air produced by small, on-site compressors was tested. Called a Purilair, this device heats every particle of inflowing compressed air to 250 degrees C and then forces it through a fine-pore ceramic filter. In three private practice operatories, an in-line Purilair effectively sterilized the air being delivered by small compressors. The same result was obtained in the laboratory when lyophilized spores and cells of Bacillus stearothermophilus and conidia of Penicillium notatum and Aspergillus niger were sprayed into the intake line of the apparatus. PMID:9473876

  4. Elimination of microorganisms from dental operatory compressed air.

    Science.gov (United States)

    De Ciccio, A; Chan, E C

    1998-01-01

    Compressed air is used to power high-speed handpieces, as well as to dry and clean surfaces in the oral cavity during patient treatment, in all dental operatories. The compressed air used in the dental operatories located in large institutions such as universities or hospitals is generally obtained from a central source, and is produced by continually running compressors. In operatories located in private practice settings, compressed air is obtained from small on-site air compressors, which may be run less frequently. A survey was made of operatories in the Montreal area to determine the microbial load of the compressed air produced by air compressors. An air sampler was used to collect compressed air and impinge it on a rotating agar medium surface. Compared to the air produced from compressors in constant use, the air collected from compressors that ran intermittently had a very high microbial load. The efficacy of an apparatus designed to sterilize the contaminated air produced by small, on-site compressors was tested. Called a Purilair, this device heats every particle of inflowing compressed air to 250 degrees C and then forces it through a fine-pore ceramic filter. In three private practice operatories, an in-line Purilair effectively sterilized the air being delivered by small compressors. The same result was obtained in the laboratory when lyophilized spores and cells of Bacillus stearothermophilus and conidia of Penicillium notatum and Aspergillus niger were sprayed into the intake line of the apparatus.

  5. 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.

  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. 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

  10. 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.

  11. Experimental Study on Coal-Breaking Pressure for Compressed Air

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on lab model experiments and through the limit analysis, the theoretical formula of calculauoncoal-breaking pressure with compressed air was derived. The experimental result shows that blasting pressure mustexceed 84.0 MPa to break coal with compressive strength of 13.2 MPa. The research provides an important theoretical basis for the design of airshooting mining and industrial tests.

  12. Investigation on wind energy-compressed air power system

    Institute of Scientific and Technical Information of China (English)

    贾光政; 王宣银; 吴根茂

    2004-01-01

    Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 29 CFR 1926.803 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... of fresh air shall be provided. (5) Whenever heat-producing machines (moles, shields) are used in... be equipped with noncombustible, nonabsorptive, insulating sockets, approved handles, basket...

  18. 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.

  19. 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.

  20. 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.

  1. 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)

  2. Environmental concerns related to compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Stottlemyre, J. A.; Craig, R. A.; Loscutoff, W. V.; Boehm, D. W.; Chang, G. C.

    1978-01-01

    The report describes the technologies of compressed air energy storage and some of the environmental concerns associated with siting, construction, operation and decommissioning of such a system. Also described is an ongoing research program, the goal of which is to evaluate methods to control the effects of these environmental factors.

  3. 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.

  4. 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 - ...

  5. 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.

  6. ADELE adiabatic compressed air energy storage. Status and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Sebastian [General Electric Deutschland Holding GmbH, Garching (Germany). GE Global Research Renewable Energy Systems Lab.; Marquardt, Roland; Moser, Peter [RWE Power AG, Essen (Germany). Research and Development Innovative Power Plant Technology

    2013-06-01

    This paper gives an overview about compressed air energy storage (CAES) technology and a summary of the ADELE programme, a multi-year R and D programme undertaken by a consortium led by RWE Power to develop adiabatic (A) CAES technology and commercialise the first plant. The ACAES technology is to utilise waste heat developing upon compression in order to increase the entire efficiency. The ADELE-ING project is to provide the basis for making the decision on the construction of a 85 MW prototype. (orig.)

  7. 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...

  8. 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.

  9. 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...

  10. 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

  11. 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

  12. Compressed air energy storage technology program. Annual report for 1979

    Energy Technology Data Exchange (ETDEWEB)

    Loscutoff, W.V.

    1980-06-01

    The objectives of the Compressed Air Energy Storage (CAES) program are to establish stability criteria for large underground reservoirs in salt domes, hard rock, and porous rock used for air storage in utility applications, and to develop second-generation CAES technologies that have minimal or no dependence on petroleum fuels. During the year reported reports have been issued on field studies on CAES on aquifers and in salt, stability, and design criteria for CAES and for pumped hydro-storage caverns, laboratory studies of CAES in porous rock reservoris have continued. Research has continued on combined CAES/Thermal Energy Storage, CAES/Solar systems, coal-fired fluidized bed combustors for CAES, and two-reservoir advanced CAES concepts. (LCL)

  13. 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.

  14. 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...

  15. 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

  16. 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

  17. 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.

  18. 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).

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Theoretical preconditions and technical substantiation for mechanical compressed air drying method application on the railway transport

    Directory of Open Access Journals (Sweden)

    Tatiana RIPOL’-SARAGOSI

    2009-01-01

    Full Text Available The article is related to the compressed air purification for the rolling stock problems. The mechanical method is described as a potential way of the compressed air cooling and purificating. The temperature field at the heat conducting surface engineer function equation is given in the article as well.

  4. 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...

  5. A review on compressed-air energy use and energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Saidur, R.; Hasanuzzaman, M. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Rahim, N.A. [Department of Electrical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-05-15

    Compressed-air systems account for about 10% of total industrial-energy use for few selected countries as found in literatures. Compressed air is typically one of the most expensive utilities in an industrial facility. This paper describes a comprehensive literature review about compressed air energy use, savings, and payback period of energy efficient strategies. This paper compiles latest literatures in terms of thesis (MS and PhD), journal articles, conference proceedings, web materials, reports, books, handbooks on compressed air energy use, efficiency, energy savings strategies. Computer tools for compressed air analysis have been reviewed and presented in this paper. Various energy-saving measures, such as use of highly efficient motors, VSD, leak prevention, use of outside intake air, reducing pressure drop, recovering waste heat, use of efficient nozzle, and use of variable displacement compressor to save compressed-air energy have been reviewed. Based on review results, it has been found that for an electric motor used in a compressed-air system, a sizeable amount of electric energy and utility bill can be saved using high efficient motors and applying VSDs in matching speed requirements. Also, significant amounts of energy and emission are reducible through various energy-saving strategies. Payback periods for different energy savings measures have been identified and found to be economically viable in most cases. (author)

  6. 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.

  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. 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

  9. 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.

  10. 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.

  11. 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.

  12. Compressible Air Entrapment in High-Speed Drop Impacts on Solid Surfaces

    CERN Document Server

    Liu, Yuan; Xu, Lei

    2012-01-01

    Using high-speed photography coupled with optical interference, we experimentally study the air entrapment during a liquid drop impacting a solid substrate. We observe the formation of a compressed air film before the liquid touches the substrate, with internal pressure considerably higher than the atmospheric value. The degree of compression highly depends on the impact velocity, as explained by balancing the liquid deceleration with the large pressure of compressed air. After contact, the air film expands vertically at the edge, reducing its pressure within a few tens of microseconds and producing a thick rim on the perimeter. This thick-rimmed air film subsequently contracts into an air bubble, governed by the complex interaction between surface tension, inertia and viscous drag. Such a process is universally observed for impacts above a few centimeters high.

  13. 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.

  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

    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.

  16. 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.

  17. Nonlinear property of slightly compressible media permeated with air-filled bubbles

    Institute of Scientific and Technical Information of China (English)

    Bo QIN

    2009-01-01

    Based on the nonlinear oscillation of an air- filled bubble in weakly compressible media at prestressed state, the effective medium method is used to study the nonlinear property of the slightly compressible media permeated with air bubbles. It is this nonlinear oscilla- tion of air bubbles that results in the nonlinear property of the porous media. Numerical results have confirmed that the nonlinearity of the porous media is usually high, though the optimal porosity is very small. Moreover, the nonlinear property is greatly affected by the prestressed state, porosity, and shear modulus of the matrix media.

  18. 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.

  19. 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...

  20. Vapour and air bubble collapse analysis in viscous compressible water

    Directory of Open Access Journals (Sweden)

    Gil Bazanini

    2001-01-01

    Full Text Available Numerical simulations of the collapse of bubbles (or cavities are shown, using the finite difference method, taking into account the compressibility of the liquid, expected to occur in the final stages of the collapse process. Results are compared with experimental and theoretical data for incompressible liquids, to see the influence of the compressibility of the water in the bubble collapse. Pressure fields values are calculated in an area of 800 x 800 mm, for the case of one bubble under the hypothesis of spherical symmetry. Results are shown as radius versus time curves for the collapse (to compare collapse times, and pressure curves in the plane, for pressure fields. Such calculations are new because of their general point of view, since the existing works do not take into account the existence of vapour in the bubble, neither show the pressure fields seen here. It is also expected to see the influence of the compressibility of the water in the collapse time, and in the pressure field, when comparing pressure values.

  1. 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

  2. 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)

  3. 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)

  4. Verification of a fully coupled FE model for tunneling under compressed air

    Energy Technology Data Exchange (ETDEWEB)

    Oettl, G.; Stark, R.F.; Hofstetter, G. [Innsbruck Univ. (Austria). Inst. for Structural Analysis and Strength of Materials

    2001-07-01

    This paper deals with the verification of a fully coupled finite element model for tunneling under compressed air. The formulation is based on mixture theory treating the soil as a three-phase medium with the constituents: deformable porous soil skeleton, water and air. Starting with a brief outline of the governing equations results of numerical simulations of different laboratory tests and of a large-scale in-situ test are presented and compared with experimental data. (orig.)

  5. 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)

  6. 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.

  7. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... other unfired pressure vessels. 56.13015 Section 56.13015 Mineral Resources MINE SAFETY AND HEALTH... and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels... applicable chapters of the National Board Inspection Code, a Manual for Boiler and Pressure Vessel...

  8. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... other unfired pressure vessels. 57.13015 Section 57.13015 Mineral Resources MINE SAFETY AND HEALTH... receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure... the applicable chapters of the National Board Inspection Code, a Manual for Boiler and Pressure...

  9. Acoustic Localization in Weakly Compressible Elastic Media Permeated with Air Bubbles

    Institute of Scientific and Technical Information of China (English)

    LIANG Bin; ZHU Zhe-Min; CHENG Jian-Chun

    2006-01-01

    @@ The propagation of longitudinal acoustic waves in weakly compressible elastic media permeated with air bubbles is investigated on the basis of the radial pulsation equation of a single bubble. The multiple scattering of waves in such media is rigorously described by using a self-consistent approach.

  10. 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....

  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. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  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. 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...

  18. [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

  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. 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...

  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. 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.

  3. 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...

  4. 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.

  5. 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...

  6. 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.

  7. Design Fabrication And Partial-Analysis Of A 2-Wheeler Prototype That Runs On Compressed Air

    Directory of Open Access Journals (Sweden)

    P Vinay

    2015-08-01

    Full Text Available Abstract The primary objective of the project is to create a prototype of a purely air powered motorcycle by retrofitting its internal combustion engine to run on compressed air. Firstly the conventional spark plug was replaced with a solenoid valve. The solenoid valve was initially actuated using a reed switch and magnet duo but then later replaced with an optical crank position sensor circuit due to reasons that include lack of control over the amount of air injected during each stroke and also for more precise control over the opening and closing of the valve. The torque brake power indicated power air consumption rate of the engine under load are calculated. Separate mounts for the modified engine and the cylindrical storage unit are designed and analysed using Catia v4. Also possible ways of future scope of the prototype are mentioned.

  8. 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.

  9. 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)

  10. 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

  11. Compressed air energy storage in depleted natural gas reservoirs: effects of porous media and gas mixing

    Science.gov (United States)

    Oldenburg, C. M.; Pan, L.

    2015-12-01

    Although large opportunities exist for compressed air energy storage (CAES) in aquifers and depleted natural gas reservoirs, only two grid-scale CAES facilities exist worldwide, both in salt caverns. As such, experience with CAES in porous media, what we call PM-CAES, is lacking and we have relied on modeling to elucidate PM-CAES processes. PM-CAES operates similarly to cavern CAES. Specifically, working gas (air) is injected through well(s) into the reservoir compressing the cushion gas (existing air in the reservoir). During energy recovery, high-pressure air from the reservoir flows first into a recuperator, then into an expander, and subsequently is mixed with fuel in a combustion turbine to produce electricity, thereby reducing compression costs. Energy storage in porous media is complicated by the solid matrix grains which provide resistance to flow (via permeability in Darcy's law); in the cap rock, low-permeability matrix provides the seal to the reservoir. The solid grains also provide storage capacity for heat that might arise from compression, viscous flow effects, or chemical reactions. The storage of energy in PM-CAES occurs variably across pressure gradients in the formation, while the solid grains of the matrix can release/store heat. Residual liquid (i.e., formation fluids) affects flow and can cause watering out at the production well(s). PG&E is researching a potential 300 MW (for ten hours) PM-CAES facility in a depleted gas reservoir near Lodi, California. Special considerations exist for depleted natural gas reservoirs because of mixing effects which can lead to undesirable residual methane (CH4) entrainment and reactions of oxygen and CH4. One strategy for avoiding extensive mixing of working gas (air) with reservoir CH4 is to inject an initial cushion gas with reduced oxygen concentration providing a buffer between the working gas (air) and the residual CH4 gas. This reduces the potential mixing of the working air with the residual CH4

  12. 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.

  13. 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.

  14. 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...

  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. Class B Fire-Extinguishing Performance Evaluation of a Compressed Air Foam System at Different Air-to-Aqueous Foam Solution Mixing Ratios

    Directory of Open Access Journals (Sweden)

    Dong-Ho Rie

    2016-06-01

    Full Text Available The purpose of this research is to evaluate the fire-extinguishing performance of a compressed air foam system at different mixing ratios of pressurized air. In this system, compressed air is injected into an aqueous solution of foam and then discharged. The experimental device uses an exclusive fire-extinguishing technology with compressed air foam that is produced based on the Canada National Laboratory and UL (Underwriters Laboratories 162 standards, with a 20-unit oil fire model (Class B applied as the fire extinguisher. Compressed air is injected through the air mixture, and results with different air-to-aqueous solution foam ratios of 1:4, 1:7, and 1:10 are studied. In addition, comparison experiments between synthetic surfactant foam and a foam type which forms an aqueous film are carried out at an air-to-aqueous solution foam ratio of 1:4. From the experimental results, at identical discharging flows, it was found that the fire-extinguishing effect of the aqueous film-forming foam is greatest at an air-to-aqueous solution foam ratio of 1:7 and weakest at 1:10. Moreover, the fire-extinguishing effect of the aqueous film-forming foam in the comparison experiments between the aqueous film-forming foam and the synthetic surfactant foam is greatest.

  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. 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.

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  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. Economic Analysis of using Above Ground Gas Storage Devices for Compressed Air Energy Storage System

    Institute of Scientific and Technical Information of China (English)

    LIU Jinchao; ZHANG Xinjing; XU Yujie; CHEN Zongyan; CHEN Haisheng; TAN Chunqing

    2014-01-01

    Above ground gas storage devices for compressed air energy storage (CAES) have three types:air storage tanks,gas cylinders,and gas storage pipelines.A cost model of these gas storage devices is established on the basis of whole life cycle cost (LCC) analysis.The optimum parameters of the three types are determined by calculating the theoretical metallic raw material consumption of these three devices and considering the difficulties in manufacture and the influence of gas storage device number.The LCCs of the three types are comprehensively analyzed and compared.The result reveal that the cost of the gas storage pipeline type is lower than that of the other two types.This study may serve as a reference for designing large-scale CAES systems.

  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. Numerical Study of Water Production from Compressible Moist-Air Flow

    Directory of Open Access Journals (Sweden)

    sabah hamidi

    2016-01-01

    Full Text Available In this research a numerical study of water production from compressible moist-air flow by condensing of the vapor component of the atmospheric air through a converging-diverging nozzle is performed. The atmospheric air can be sucked by a vacuum compressor. The geographical conditions represent a hot and humid region, for example Bandar Abbas, Iran, with coordinates, 270 11 ’ N and 560 16’ E and summer climate conditions of about 40℃and relative humidity above 80%. Parametric studies are performed for the atmospheric-air temperature between, 40℃ to 50℃, and relative humidity between49.6% to 100.%. For these ranges of operating conditions and a nozzle with the area ratio of 1.17, the liquid mass flow rates falls in the range 0.272 to 0.376 kg/s. The results show that, the energy consumed by the compressor for production 1 kg of water will be 1.279 kWh. The price of 1 kWh is 372 Rials, therefore the price for the production of 1 kg liquid water will be 475.8 Rials, therefore, the scheme is economically suitable.

  12. 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)

  13. 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%.

  14. 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.

  15. Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

    Science.gov (United States)

    Flynn, M R; Gatano, B L; McKernan, J L; Dunn, K H; Blazicko, B A; Carlton, G N

    1999-01-01

    This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters. PMID:10028895

  16. Technical and economic assessment of fluidized bed augmented compressed air energy storage system. Volume III. Preconceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Giramonti, A.J.; Lessard, R.D.; Merrick, D.; Hobson, M.J.

    1981-09-01

    A technical and economic assessment of fluidized bed combustion augmented compressed air energy storage systems is presented. The results of this assessment effort are presented in three volumes. Volume III - Preconceptual Design contains the system analysis which led to the identification of a preferred component configuration for a fluidized bed combustion augmented compressed air energy storage system, the results of the effort which transformed the preferred configuration into preconceptual power plant design, and an introductory evaluation of the performance of the power plant system during part-load operation and while load following.

  17. 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

  18. Acoustic localization in weakly compressible elastic media containing random air bubbles.

    Science.gov (United States)

    Liang, Bin; Cheng, Jian-chun

    2007-01-01

    We study theoretically the propagation of longitudinal wave in weakly compressible elastic media containing random air bubbles by using a self-consistent method. By inspecting the scattering cross section of an individual bubble and estimating the mean free paths of the elastic wave propagating in the bubbly weakly compressible media, the mode conversion is numerically proved negligible as the longitudinal wave is scattered by the bubbles. On the basis of the bubble dynamic equation, the wave propagation is solved rigorously with the multiple scattering effects incorporated. In a range of frequency slightly above the bubble resonance frequency, the acoustic localization in such a class of media is theoretically identified with even a very small volume fraction of bubbles. We present a method by analyzing the spatial correlation of wave field to identify the phenomenon of localization, which turns out to be effective. The sensibility of the features of localization to the structure parameters is numerically investigated. The spatial distribution of acoustic energy is also studied and the results show that the waves are trapped within a spatial domain adjacent to the source when localization occurs.

  19. 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.

  20. 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

    independent computer-based methodologies which may be used for identifying the optimal operation strategy for a given CAES plant, on a given spot market and in a given year. The optimal strategy is identified as the one which provides the best business-economic net earnings for the plant. In practice, CAES......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 three...

  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. 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.

  4. 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.

  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. 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

  7. 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.

  8. 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...

  9. 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...

  10. 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

  11. 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...

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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”。

  17. 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

  18. 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....

  19. 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...

  20. 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.

  1. Exploring the concept of compressed air energy storage (CAES) in lined rock caverns at shallow depth: A modeling study of air tightness and energy balance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.-M.; Rutqvist, J.; Ryu, D.-W.; Choi, B.-H.; Sunwoo, C.; Song, W.-K.

    2011-07-15

    This paper presents a numerical modeling study of coupled thermodynamic, multiphase fluid flow and heat transport associated with underground compressed air energy storage (CAES) in lined rock caverns. Specifically, we explored the concept of using concrete lined caverns at a relatively shallow depth for which constructing and operational costs may be reduced if air tightness and stability can be assured. Our analysis showed that the key parameter to assure long-term air tightness in such a system was the permeability of both the concrete lining and the surrounding rock. The analysis also indicated that a concrete lining with a permeability of less than 1×10{sup -18} m{sup 2} would result in an acceptable air leakage rate of less than 1%, with the operational pressure range between 5 and 8 MPa at a depth of 100 m. It was further noted that capillary retention properties and the initial liquid saturation of the lining were very important. Indeed, air leakage could be effectively prevented when the air-entry pressure of the concrete lining is higher than the operational air pressure and when the lining is kept moist at a relatively high liquid saturation. Our subsequent energy-balance analysis demonstrated that the energy loss for a daily compression and decompression cycle is governed by the air-pressure loss, as well as heat loss by conduction to the concrete liner and surrounding rock. For a sufficiently tight system, i.e., for a concrete permeability off less than 1×10{sup -18} m{sup 2}, heat loss by heat conduction tends to become proportionally more important. However, the energy loss by heat conduction can be minimized by keeping the air-injection temperature of compressed air closer to the ambient temperature of the underground storage cavern. In such a case, almost all the heat loss during compression is gained back during subsequent decompression. Finally, our numerical simulation study showed that CAES in shallow rock caverns is feasible from a leakage

  2. 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

  3. 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.

  4. 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....

  5. 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....

  6. 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.

  7. 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)

  8. 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

  9. 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.

  10. Citizen Hydrology and Compressed-Air Hydropower for Rural Electrification in Haiti

    Science.gov (United States)

    Allen, S. M.

    2015-12-01

    At the present time, only one in eight residents of Haiti has access to electricity. Two recent engineering and statistical innovations have the potential for vastly reducing the cost of installation of hydropower in Haiti and the rest of the developing world. The engineering innovation is that wind, solar and fluvial energy have been used to compress air for generation of electricity for only 20 per megawatt-hour, in contrast to the conventional World Bank practice of funding photovoltaic cells for 156 per megawatt-hour. The installation of hydropower requires a record of stream discharge, which is conventionally obtained by installing a gaging station that automatically monitors gage height (height of the water surface above a fixed datum). An empirical rating curve is then used to convert gage height to stream discharge. The multiple field measurements of gage height and discharge over a wide range of discharge values that are required to develop and maintain a rating curve require a manpower of hydrologic technicians that is prohibitive in remote and impoverished areas of the world. The statistical innovation is that machine learning has been applied to the USGS database of nearly four million simultaneous measurements of gage height and discharge to develop a new classification of rivers so that a rating curve can be developed solely from the stream slope, channel geometry, horizontal and vertical distances to the nearest upstream and downstream confluences, and two pairs of discharge - gage height measurements. The objective of this study is to organize local residents to monitor gage height at ten stream sites in the northern peninsula of Haiti over a one-year period in preparation for installation of hydropower at one of the sites. The necessary baseline discharge measurements and channel surveying are being carried out for conversion of gage height to discharge. Results will be reported at the meeting.

  11. 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.

  12. 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)

  13. 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...

  14. 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 luftforuren...

  15. Skoling af lyst

    DEFF Research Database (Denmark)

    Bjerg, Helle

    2011-01-01

    På baggrund af interview med tre elevgenerationer fremanalyseres skolens virkningsfuldhed i skoling af lyst i et historisk perspektiv. I afhandlingen udvikles to teoretisk-analytiske optikker: Skolen som ideologisk rum - med inspiration fra Slavoj Zizeks ideologikritik, samt Skolen som affektivt...

  16. 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)...

  17. 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...

  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. 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.

  20. Billeder af verdens svovl

    DEFF Research Database (Denmark)

    Samson, Kristine

    2014-01-01

    Film- og billedmediet har en særlig plads i skildringen af vores samfund og økonomi. Produktionen i de vestlige samfund består i dag primært af tegn, symboler, billeder og begær, mens de forgangne tiders maskinelle og, ikke mindst, manuelle bearbejdning af materialer – det vi stadigvæk umiddelbar...

  1. 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...

  2. Forankring af skolemadsordninger

    DEFF Research Database (Denmark)

    Brinck, Nenna Maria; Kristensen, Niels Heine; Hansen, Mette Weinreich

    Denne rapport præsenterer resultaterne af de undersøgelser, der er gennemført i delprojekt 4 i EVIUS evalueringen. Fokus i dette delprojekt er forankringen af skolemadsordningerne. Af undersøgelsen fremgår det, at støtteordningen har virket bedst på skoler, hvor skolelederen har inddraget elever,...

  3. 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...

  4. Udformning af en forskningsprotokol

    DEFF Research Database (Denmark)

    Ridder, Hanne Mette Ochsner; Ottesen, Aase Marie

    2008-01-01

    Nogle demenssygdomme rammer især de forreste dele af hjernen, hvilket hos den enkelte person kan medføre svære psykiatriske symptomer. Der findes ingen specifik behandling af grundsygdommene for disse frontotemporaledemenstilstande, og symptomatisk medikamentel behandling af de psykiatriske sympt...

  5. 应用改良AF脊柱内固定系统经皮微创内固定治疗胸腰椎压缩骨折%The Application of Improved AF Spinal Internal Fixation System With Percutaneous Minimally Invasive Internal Fixation for the Treatment of Thoracic and Lumbar Vertebral Compression Fracture

    Institute of Scientific and Technical Information of China (English)

    李晓龙; 王志军

    2015-01-01

    Objective To explore the efficacy of the AF spinal internal fixation system with percutaneous minimally invasive internal fixation for the treatment of thoracic and lumbar vertebral compression fracture. Methods Collected in our hospital 48 cases of thoracolumbar compression fractures, application of improved percutaneous minimally invasive internal fixation of AF spinal internal fixation system in the treatment of thoracolumbar compression fractures, postoperative review X-ray for curative effect analysis. Results 48 cases of compression injury vertebral height of vertebral body than preoperative obviously restoration, 90%of the average recovery to normal height of vertebral body Conclusion Application of improved percutaneous minimally invasive internal ifxation of AF spinal internal fixation system in the treatment of thoracolumbar compression fractures curative effect is distinct.%目的:探讨应用AF脊柱内固定系统经皮微创内固定治疗胸腰椎压缩骨折的疗效。方法收集本院48例胸腰椎压缩骨折,应用改良AF脊柱内固定系统经皮微创内固定治疗胸腰椎压缩骨折,术后复查X片进行疗效分析。结果48例压缩的伤椎椎体高度比术前明显得到恢复,平均恢复至正常椎体高度的90%。结论应用改良AF脊柱内固定系统经皮微创内固定治疗胸腰椎压缩骨折疗效显著。

  6. Nedbrydning af barrierer for brug af alternative isoleringsmaterialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2003-01-01

    Resume af rapport om fremme af anvendelsen af alternative isoleringsmaterialer ved nedbrydning af barrierer af traditionel, teknisk og lovgivningsmæssig karakter, udarbejdet af Landsforeningen Økologisk Byggeri (LØB) under Energistyrelsens udviklingsprogram "Miljø- og arbejdsmiljøvenlig isolering"...

  7. 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)

  8. 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

  9. 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...

  10. Storage of compressed air. A possibility for an enhanced utilization of wind energy?; Druckluftspeicherung. Ein Weg zur verstaerkten Windenergienutzung?

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmer, Rutger [DREWAG - Stadtwerke Dresden GmbH, Dresden (Germany). Hauptabt. Vertrieb und Beschaffung

    2008-07-01

    The high prices for fossil energy sources are due to increasing demand, limited production quotas and exhaustion of strategically positioned deposits. Likewise the electricity prices increase to. High electricity tariffs improve the investment climate for renewable energies independently from the fuel costs. The positive development of the renewable energy is accompanied by serious disadvantages. Thus, the conditions for grid control and for the operation of fossil power stations deteriorate. The author of the contribution under consideration reports on the storage of compressed air as a possibility for the use of wind energy.

  11. 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 A

    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.

  12. 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...

  13. 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....

  14. 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....

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H.; Dimitrova, M. [Wind Energy TechnoCentre, 51 Chemin de la mine, C.P. 1300, Murdochville, Quebec (Canada); Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300, allee des Ursulines, Quebec (Canada); Anti-icing Materials International Laboratory (AMIL), Universite du Quebec a Chicoutimi, 555, boulevard de l' Universite, Quebec (Canada); Younes, R. [Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300, allee des Ursulines, Quebec (Canada); 3M Laboratory - Faculty of Engineering, Lebanese University, Beirut (Lebanon); Ilinca, A. [Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300, allee des Ursulines, Quebec (Canada); Perron, J. [Anti-icing Materials International Laboratory (AMIL), Universite du Quebec a Chicoutimi, 555, boulevard de l' Universite, Quebec (Canada)

    2010-05-15

    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. (author)

  17. 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.

  18. Application of wavelet filtering and Barker-coded pulse compression hybrid method to air-coupled ultrasonic testing

    Science.gov (United States)

    Zhou, Zhenggan; Ma, Baoquan; Jiang, Jingtao; Yu, Guang; Liu, Kui; Zhang, Dongmei; Liu, Weiping

    2014-10-01

    Air-coupled ultrasonic testing (ACUT) technique has been viewed as a viable solution in defect detection of advanced composites used in aerospace and aviation industries. However, the giant mismatch of acoustic impedance in air-solid interface makes the transmission efficiency of ultrasound low, and leads to poor signal-to-noise (SNR) ratio of received signal. The utilisation of signal-processing techniques in non-destructive testing is highly appreciated. This paper presents a wavelet filtering and phase-coded pulse compression hybrid method to improve the SNR and output power of received signal. The wavelet transform is utilised to filter insignificant components from noisy ultrasonic signal, and pulse compression process is used to improve the power of correlated signal based on cross-correction algorithm. For the purpose of reasonable parameter selection, different families of wavelets (Daubechies, Symlet and Coiflet) and decomposition level in discrete wavelet transform are analysed, different Barker codes (5-13 bits) are also analysed to acquire higher main-to-side lobe ratio. The performance of the hybrid method was verified in a honeycomb composite sample. Experimental results demonstrated that the proposed method is very efficient in improving the SNR and signal strength. The applicability of the proposed method seems to be a very promising tool to evaluate the integrity of high ultrasound attenuation composite materials using the ACUT.

  19. 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...

  20. 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 ...

  1. 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....

  2. 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

  3. Kuratering af Samtidskunst

    DEFF Research Database (Denmark)

    Kuratering af Samtidskunst er den første bogudgivelse i Danmark, der fokuserer på kuratering som fag og praksis. Kuratering spiller en stadig større rolle i samtidskunsten. Bogen er en introduktion til skiftende forståelser af udstillings- og kuratorpraksisser og deres udfordringer, indkredset ge...

  4. Kvalitetsvurdering af sundhedsoplysende materiale

    DEFF Research Database (Denmark)

    Osler, Merete; Bech, Lars; Sybille, Bojlén;

    1990-01-01

    Lægeforeningens Hygiejnekomités arbejdsgruppe vedrørende sundhedsoplysning har udarbejdet en "huskeliste" til brug for en kvalitetsvurdering af skriftligt sundhedsoplysende materiale......Lægeforeningens Hygiejnekomités arbejdsgruppe vedrørende sundhedsoplysning har udarbejdet en "huskeliste" til brug for en kvalitetsvurdering af skriftligt sundhedsoplysende materiale...

  5. Ud af guldrammerne

    DEFF Research Database (Denmark)

    Munch, Anders V.

    2006-01-01

    Diskussion af den internationale indflydelse på dansk symbolisme og skønvirke med udgangspunkt i Johan Rohdes rejsejournaler og Emil Hannovers anmeldelser af internationale udstillinger og udgivelser. Særligt fokus er Gesamtkunstwerk-tanken som baggrund for at koble kunst og kunsthåndværk....

  6. Dialektisk billede af Benjamin

    DEFF Research Database (Denmark)

    Bøggild, Jacob

    2004-01-01

    Anmeldelse af Lars Brückner: "Løse blade. Læseren, kritikeren og fortælleren Walter Benjamin"......Anmeldelse af Lars Brückner: "Løse blade. Læseren, kritikeren og fortælleren Walter Benjamin"...

  7. Implementering af evidensbaseret praksis

    DEFF Research Database (Denmark)

    Scheel, Linda Schumann; Tewes, Marianne; Petersen, Preben Ulrich

    2015-01-01

    Projektet omhandler implementering af den kliniske retningslinje om identifikation, forebyggelse og behandling af delirium – i denne sammenhæng relateret til hjertepatienter. Projektet foregår på to hospitaler i Hjertecentret på Rigshospitalet, et intensivt afsnit og et sengeafsnit, i tæt...

  8. 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...

  9. Hvordan integration af it?

    DEFF Research Database (Denmark)

    Toft, Herdis

    2008-01-01

    Bourdieu-perspektiv og en analyse af data fra museums- og skoleprojektet Din egen historie på nettet vises det, hvordan børnene opbygger en legehabitus, det vil sige aktivt tilegner sig og anvender færdigheder i brug af æstetiske teknikker, som er formler, de kan improvisere frit over. Kendskab til formler...

  10. 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...

  11. Implementering af evidensbaseret praksis

    DEFF Research Database (Denmark)

    Scheel, Linda Schumann; Hansen, Ida Rode

    2014-01-01

    Projektet omhandler implementering af den kliniske retningslinje om identifikation, forebyggelse og behandling af delirium – i denne sammenhæng relateret til hjertepatienter. Projektet foregår på to hospitaler i Hjertecentret på Rigshospitalet, et intensivt afsnit og et sengeafsnit, i tæt...

  12. Midtvejsevaluering af EGA handlingsplanen

    DEFF Research Database (Denmark)

    Møller, Niels; Hasle, Peter; Christiansen, Jørgen Møller;

    Center for Alternativ Samfundsanalyse (CASA) og Institut for Teknologi og Samfund ved Danmarks Tekniske Universitet har gennemført denne midtvejsevaluering af arbejdsmarkedets parters handlingsplan mod reduktion af ensidigt gentaget arbejde. Undersøgelsen viser, at der er sket en betydelig...

  13. 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...

  14. Indsattes organisering af selvforplejning

    DEFF Research Database (Denmark)

    Kjær Minke, Linda

    2012-01-01

    organiserer sig i madgrupper. Dette dels af økonomiske og praktiske hensyn, men madgrupperne fungerer også som mulighedsrum til fremvisning af forskellige former for kapital, positionering og magt. Madgrupperne har derfor både økonomiske og sociale formål og har betydning for indsattes strategier i...

  15. 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...

  16. 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...

  17. 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...

  18. 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.

  19. Enhancement of the radar signal of air showers due to time compression

    CERN Document Server

    Stasielak, J; Engel, R; Neunteufel, P; Pekala, J; Šm\\'\\ida, R; Werner, F; Wilczyński, H

    2013-01-01

    We investigate the feasibility of detecting extensive air showers by the radar technique at viewing angles smaller than $\\sim 25^\\circ$ to the shower axis. Considering a bistatic radar setup and shower geometries in which the receiver points into the arriving shower, we simulate reflection of radio waves off the short-lived plasma produced by the high-energy shower particles in the air. Using the Thomson cross-section for scattering of radio waves and summing coherently contributions of the reflected radio wave over the volume of the plasma disk, we obtain the time evolution of the signal. We analyze the spectral power density of the radar echo and the received power. Based on the obtained results, we discuss possible modes of the radar detection of extensive air showers.

  20. 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

  1. 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).

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. Compressed air energy storage: Preliminary design and site development program in an aquifer. Task 1: Establish facility design criteria and utility benefits

    Science.gov (United States)

    1980-10-01

    Compressed air energy storage (CAES) stores mechanical energy in the form of compressed air during off-peak hours, using power supplied by a large, high efficiency baseload power plant. At times of high electrical demand, the compressed air is drawn from storage and is heated in a combustor by the burning of fuel oil, after which the air is expanded in a turbine. Essentially all of the turbine output can be applied to the generation of electricity, unlike a conventional gas turbine which expends approximately two-thirds of the turbine shaft power in driving the air compressor. The separation of the compression and generation modes in the system results in increased net generation and greater premium fuel economy. Work performed in establishing facility design criteria for a CAES system with aquifer storage includes: determination of initial design bases; preliminary analysis of the CAES system; development of data for site-specific analysis of the CAES system; detailed analysis of the CAES system for three selected heat cycles; CAES power plant design; and an economic analysis of CAES.

  7. Smagen af svovl

    DEFF Research Database (Denmark)

    Madsen, P. V.; Sørensen, B. T.

    2007-01-01

    Et af Sydafrikas største industriområder ligger i landets tredje største by, Durban. Industriområdet kaldes for "South Durban Industrial Basin" (SDIB), hvor der er cirka 120.000 beboere. Boligerne ligger side om side med en bred variation af tung industri. Området er et sørgeligt eksempel på den ...... tidligere Apartheid styret byplanlægning, hvor regeringen i 1940'erne valgte at placere industri i et område hovedsageligt beboet af farvede og sorte mennesker....

  8. 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...

  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. 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...

  11. 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...

  12. 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...

  13. 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...

  14. Anvendelser af Pervasive Communication

    DEFF Research Database (Denmark)

    Brønsted, Jeppe

    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...... forskningsprojekter og kommercielle produkter. Dette er gjort for både at demonstrere hvor vide rammerne er for anvendelser af Pervasive Communication og for at vise at der kan laves en forretning ud af ideerne. For overskueligheds skyld er eksemplerne delt op i en række kategorier: Sundhed, transport, ordre og...

  15. 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....

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

    DEFF Research Database (Denmark)

    Pedersen, Karl; Pedersen, Kristina; Jensen, Helene;

    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...... + trimethoprim udgjorde i 2005 tilsammen 81% af det totale forbrug til kæledyr. Forekomsten af resistens overfor cephalosporiner og amoxycillin med clavulansyre var dog lav for de undersøgte isolater, med undtagelse af isolater af P. aeruginosa. Blandt S. intermedius isolaterne var 60,2% resistente overfor...

  17. Forebyggelse af kriminalitet

    DEFF Research Database (Denmark)

    Christiansen, U.; Jantzen, E.B.; Kirkegaard, O.

    Forebyggelse af kriminalitet i boligområder har længe stået på dagsordenen i alle vestlige samfund. Dansk Ingeniørforening og Ingeniørsammenslutningen har udviklet normer for kriminalpræventiv planlægning i boligområder siden midten af 1980'erne. To bebyggelser i Københavnsegnen er blevet planlag...

  18. 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...

  19. 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.

  20. 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...

  1. 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.

  2. 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)

  3. 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....

  4. 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.

  5. Compressed air storage concept BOP-B - Heat-exchanger and motor-generator; Machbarkeit des Druckluftspeicherkonzeptes BOP-B. Waermetauscher und Motgen

    Energy Technology Data Exchange (ETDEWEB)

    Brueckmann, P. [Brueckmann Elektronik, Davos Dorf (Switzerland); Cyphelly, I. [Cyphelly and Cie, Les Brenets (Switzerland); Lindegger, M. [Circle Motor AG, Guemligen (Switzerland)

    2006-11-15

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) deals with project concerning a compressed-air energy storage system. The authors state that the BOP-B is a highly efficient compressor or air motor and can work efficiently if the compression or expansion of the air takes place in a mostly isothermal way. First tests made on the heat-exchanger unit are reported on and conclusions are drawn. A second part of the paper deals with the motor-generator unit (Motgen). The mechanical and electrical construction of the Motgen is described along with the results of tests performed on the unit. The results of measurements made are presented and discussed.

  6. 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

  7. Ledelse af sociale institutioner

    DEFF Research Database (Denmark)

    Kofod, Kasper

    Ledelse af sociale institutioner giver et overblik over den enorme forandring, der er sket indenfor det sociale område i de sidste 25-30 år. Moderniseringen af den offentlige sektor har været gennemgribende, og udviklingen på det sociale område er gået mod større instirutioner og mod, at stadig...... flere beslutninger træffes lokalt. det betyder også,a t der kommeret øget fokus på ledelse af de enkelte sociale institutioner. Forandringer i omverdenedn som globalisering, individualisering, mangel på arbejdskraft og ændringer i omgangsformer påvirker også ledelsesvilkårene i de sociale institutioner...

  8. 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...

  9. 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...

  10. 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

  11. Konstruktion af sandheden

    DEFF Research Database (Denmark)

    Nørreklit, Lennart

    2009-01-01

    Artiklen fremstiller sandhedsbegrebet som et læringsideal, som erstatter absolutisme og relativisme med læring. Indledningen bestemmer en problemorienteret ramme, som teorien indgår i: Mennesket er aktør, der danner virkelighed i form af relationer til sin omverden. Sandhedsbegrebet er forudsætni...... for en løbende sandhedsbestemmende læringsproces. Artiklen slutter med en diskussion af performative problemer, hvorigennem udsagn kan påvirke deres egen sandhedsværdi....

  12. 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

  13. Assessment of air quality after the implementation of compressed natural gas (CNG) as fuel in public transport in Delhi, India.

    Science.gov (United States)

    Ravindra, Khaiwal; Wauters, Eric; Tyagi, Sushil K; Mor, Suman; Van Grieken, René

    2006-04-01

    Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM(10), CO, SO(2) and NO(x)) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO(2) and CO concentrations, while the NO(x) level was increased in comparison to those before the implementation of CNG. Further, SPM, PM(10), and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.

  14. 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

  15. 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...

  16. Forankring af skolemadsordninger

    DEFF Research Database (Denmark)

    Brinck, Nenna Maria; Kristensen, Niels Heine; Hansen, Mette Weinreich

    I rapporten beskrives tre forældrebetalte skolemadsordninger, der blev etableret med støtte fra FødevareErhverv i 2008. Rapporten indeholder også resultater fra en spørgeskemaundersøgelse foretaget blandt elever og forældre i en 4. og 8. klasse på de tre caseskoler. Rapporten er en del af evaluer...

  17. 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...

  18. 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...

  19. 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...

  20. Digitalisering af undervisning

    DEFF Research Database (Denmark)

    Christiansen, René B.; Hansen, Søren; Rossen, Svend;

    2010-01-01

    Rapporten er et bestillingsarbejde fra FU (Forskning og Udvikling) og viser en række eksempler på hvorledes undervisningsforløb kan konstrueres online. Herunder ved brug af både LMS-systemer og web 2.0-værktøjer...

  1. 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...

  2. 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...

  3. Innovationen lider af teknologifetichisme

    DEFF Research Database (Denmark)

    Pedersen, Peder Holm

    2011-01-01

    Teknologisk innovation er udråbt som vejen til fremtiden for den danske velfærdsstat. Men vi risikerer at miste innovationens fulde potentiale, hvis vi tror, at innovation nødvendigvis skal lugte af teknologi. Nogle gange kan en sort affaldssæk også gøre det....

  4. 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...

  5. 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...

  6. 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...

  7. Energieffektivisering af byggeriet - Nyhedsbrev 4

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Grøn, Dorte Marie Frilund; Mortensen, Erik

    2013-01-01

    Hermed er det fjerde nyhedsbrev fra UCN Spireindsatsen ”Energieffektivisering af byggeriet” på gaden. I brevet kan du blandt andet læse mere om relaterede afholdte og fremtidige aktiviteter samt delprojektet; Systematisk energieffektivisering af tekniske installationer.......Hermed er det fjerde nyhedsbrev fra UCN Spireindsatsen ”Energieffektivisering af byggeriet” på gaden. I brevet kan du blandt andet læse mere om relaterede afholdte og fremtidige aktiviteter samt delprojektet; Systematisk energieffektivisering af tekniske installationer....

  8. 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

  9. 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.

  10. 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.

  11. Monitering af korrosion i fjernvarmesystemer

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Thorarinsdottir, R.I.

    2004-01-01

    Kontrol af korrosion i fjernvarmesystemer foregår primært ved kontrol af vandkvaliteten. Generel korrosion af kulstofstål undgås således normalt ved at holde iltkoncentration og ledningsevne lav og pH høj. Lokaliseret korrosion forekommer dog i systemerne og disse korrosionsangreb detekteres i fo...

  12. 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...

  13. 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 ...

  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. Poser af papir og plast

    DEFF Research Database (Denmark)

    Thygesen, Jette

    2007-01-01

    Artiklen behandler de problemstillinger der er i forbindelse med fortolkning af det afgiftspligtige vareområde. I henhold til lov om afgift af visse emballager, poser, engangsservice, og pvc-folier, svares der afgift af poser, såfremt de frembyder bestemte karakteristika, herunder særligt om de er...

  16. 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.

  17. 压缩空气系统耗能与节能分析%Analyses of Energy Dissipation and Saving in Compressed Air System

    Institute of Scientific and Technical Information of China (English)

    何明勋; 陈国娟

    2012-01-01

    分析了压缩空气从压缩到输送过程的能量消耗损失,得出压缩过程损失约占总耗能的44%,卸载损失约占9%、降压使用损失约占3%,此外,泄露损失、无热再生干燥损失、管路输送损失以及环境温降损失都有不同程度的比例.针对以上各类损失,本文从设备选型、系统管路设计与安装以及优化运行3个方面提出了一系列节约能源、降低消耗的措施及改进方法,对提高能源利用效率、降低消耗有一定参考意义.%Energy lose of the compressed air system in compressing stage and transporting stage is analyzed,to definite and discriminate the whole process energy lose, air compressed energy lose, motor unloading energy lose and pressure degrading energy lose of the percentage are calculated with the CA series screw compressor as example,furthermore,the air transporting system energy lose caused by leakage, emission of regenerated dryer, pressure drop in piping line and temperature drop of the compressed air are also analyzed. To reduce the energy lose above, some measurements such as optimization equipment comfiguration, optimization piping design,system installation quality control and optimization operation perimeter are raised,these can be references for improving the energy utilization rate.

  18. 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.

  19. Compressibility of air-water pore mixture fluid%气水孔隙混合流体的压缩性

    Institute of Scientific and Technical Information of China (English)

    徐浩峰; 谢康和

    2012-01-01

    In order to obtain the calculation formula for compressibility of pore mixture fluid,which is suitable to the consolidation analysis on soil with high degree of saturation,the compression coefficient of pore mixture fluid was expressed by the pore water pressure.In the derivation process,the dissolution of air bubble in water was neglected,and the relation between air bubble pressure and water pressure was established according to Laplace formula.The influence of single air bubble on compressibility was analyzed,and the one-dimensional consolidation compression tests were performed.In addition,the formula for compression coefficient of mixture fluid was verified.The results show that three major factors affecting the compressibility of pore fluid are degree of saturation,water pressure and dispersion degree of pore air.The smaller the degree of saturation is,or the bigger the radius of air bubble is,the larger the compressibility of mixture fluid is.If the initial degree of saturation is the same,the effect of initial radius of air bubble on compression coefficient is quite small when the water pressure reaches the maximum value.Through comparing the experimental results with the results calculated by other researchers,it is proved that the proposed theoretical formula can analyze and predict the compression coefficient of pore mixture fluid better.%为了得到适用于高饱和度土固结分析的孔隙混合流体的压缩性计算公式,采用孔隙水压力来表示混合流体的压缩系数.推导过程中,不考虑气泡在水中的溶解,按Laplace公式建立气泡压强与水压的关系.分析了单个气泡对压缩性的影响,并进行了一维固结压缩试验,对混合流体的压缩系数公式进行了验证.结果表明:饱和度、水压和孔隙气的分散度是影响孔隙流体压缩性的3个主要因素;饱和度越小,气泡半径越大,混合流体的压缩性越大;若初始饱和度相同,当水压达到较大值时,气泡初始

  20. 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...

  1. Hætten af for Robin Hood

    DEFF Research Database (Denmark)

    Oxenbøll, Morten

    2010-01-01

    En historisk gennemgang af Robin Hood myten i anledning af den kommende Hood film med Russell Crowe i hovedrollen.......En historisk gennemgang af Robin Hood myten i anledning af den kommende Hood film med Russell Crowe i hovedrollen....

  2. 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...

  3. Compressed Sensing-Based Multiuser Cooperative Networks

    Institute of Scientific and Technical Information of China (English)

    付晓梅; 崔阳然

    2016-01-01

    To avoid interference, compressed sensing is introduced into multiuser cooperative network. A coopera-tive compressed sensing and amplify-and-forward(CCS-AF)scheme is proposed, and it is proved that the channel capacity increases compared with the traditional cooperative scheme by considering the CCS-AF transmission ma-trix as the measurement matrix. Moreover, a new power allocation algorithm among the relays is proposed to im-prove the channel capacity. Numerical results validate the effectiveness of the proposed scheme.

  4. 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....

  5. 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...

  6. 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...

  7. 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...

  8. 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....

  9. 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.

  10. Potential of a hybrid wind-diesel-compressed air system for a remote telecommunication station : part 2; Potentiel d'un Systeme hybride eolien-diesel-air comprime pour une station telecom isolee : partie 2

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H.; Dimitrova, M. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire LREE; Quebec Univ., Chicoutimi, PQ (Canada). Laboratoire LIMA; Chabour, H.; Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire LREE; Perron, J. [Quebec Univ., Chicoutimi, PQ (Canada). Laboratoire LIMA

    2009-07-01

    This paper reviewed the feasibility of using a hybrid wind-diesel-compressed air system to produce electricity at remote telecommunication stations. The hybrid system has been touted as a substitute for inefficient and costly diesel generators that contribute significant amounts of greenhouse gas to the atmosphere. In part 1 of this study, the authors compared different technical solutions for a high penetration wind-diesel system together with compressed air energy storage (CAES) and described the one that optimizes the performance and the cost of the overall system. Part 2 of the study examined the method of storing compressed air and the type of tank used. Results of numerical modeling of the system were then analyzed to determine the economic advantage of the hybrid system in terms of diesel fuel conservation and avoided greenhouse gases. It was concluded that the proposed design provides an increase in diesel power and efficiency, reduced fuel consumption and GHG emissions, in addition to economies on the maintenance and replacement cost of imported diesel. 3 tabs., 6 figs.

  11. 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.

  12. Korrosionshastigheder af rene zinkcoatings

    DEFF Research Database (Denmark)

    Bech-Nielsen, G.; Tang, Peter Torben; Ulrich, Dan

    1991-01-01

    Det har længe været den fremherskende opfattelse i galvanobranchen, at et zinkbad var et zinkbad og at der, tiltrods for de forskellige leverandørers gyldne løfter, ikke var den store forskel på de bade der kan købes på markedet idag. Det har ydermere været den almindelige opfattelse, at zinkbade......-bestandighed og udseende. Badenes alder har også vist sig at have endog meget stor betydning for kvaliteten af belægningerne....

  13. 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.

  14. Kulturelle spejlinger af Profeten Muhammed

    DEFF Research Database (Denmark)

    Høgsbro Lading, Åse

    2008-01-01

    Artiklen er en analyse af to forløb i den såkaldte Muhammedkrise, der udspringer af Jyllandspostens offentliggørelse af karrikaturer af profeten Muhammed. Den første i 2006 ses som et  udspil, der først og frememst er styret  af markedsmæssige interesser, og hvor de globale reaktioner kom bag på ...... forsvar opleves  af avisen i splitting-kategorier: enten kan man sige alt, eller også har man ikke ytringsfrihed. Artiklen slutter med et ønske om, at mere komplekse syn på de globale relationer kan etableres...

  15. Slaver af Væksten

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    2004-01-01

    Artiklen rejser spørgsmålet om der, foruden den miljømæssige nødvendighed af at bremse væksten i Brutto National Produktet, også er direkte meneskelige fordele ved et sådant skridt. Dette aspekt er illustreret med de stigende negative følger af velstanden i USA og andre overflodslande, i form af ...

  16. Sammenligning af energiforbrug i supermarkeder

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard

    2005-01-01

    Formålet med det her omtalte projekt har været at sammenligne energiforbruget til køling i fire supermarkeder af sammenlignelig størrelse men med forskellig opbygning af køleanlægget. To af supermarkederne har nyudviklede kaskadeanlæg med CO2 i lavtemperaturkredsen og R404A i højtemperaturkredsen...

  17. Heat recovery from the compressed air of activation tanks at Herdorf sewage plant. Final report; Waermerueckgewinnung aus der Druckluft von Belebungsanlagen am Beispiel der Verbandsklaeranlage Herdorf. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Witte, H.; Strunkheide, J.; Eckhardt, R.

    2001-01-01

    Heat is removed from the compressed air of the activation tanks via a separate air cooler installed in the compressed-air line leading to the activation tank. The heat recovered will heat up the sludge in the digestion tank or will be fed into the heating system of the plant. The following goals are defined: Savings of heating oil; Saving of digestion gas as completely as possible; Power generation from the saved gas in a cogeneration unit; Power supply to the public grid. [German] Zielsetzung des Pilotprojektes ist die Nutzung der Druckluftwaerme von Belebungsanlagen als eine Moeglichkeit der Energieeinsparung auf Klaeranlagen. Die Nutzung der Verlustwaerme soll durch Abgriff der Waerme ueber einen separaten Luftkuehler erfolgen, der direkt in der Druckluftleitung zum Belebungsbecken installiert ist. Die auf diese Weise zurueckgewonnene Waerme soll zur Rohschlammaufheizung im Faulungsprozess dienen bzw. in das Betriebsheizungssystem eingespeist werden. Somit koennen folgende Ziele der Waermerueckgewinnungsanlage ins Auge gefasst werden: - Einsparung von Heizoel zu Heizzwecken in den Betriebsanlagen der Klaeranlage - Moeglichst komplette Einsparung von Faulgas im Heizkessel daraus folgend: - Mehrverstromung der im Heizkessel weniger verbrauchten Gasmengen im Blockheizkraftwerk (BHKW) mit dem Ergebnis: - Wirtschaftlicher Ertrag durch Einspeisung dieser Mehrmengen an Strom in das oeffentliche Versorgungsnetz. (orig.)

  18. Energieffektivisering af byggeriet - Nyhedsbrev 2

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Grøn, Dorte Marie Frilund

    2013-01-01

    Hermed er andet nyhedsbrev fra UCN Spireindsatsen ”Energieffektivisering af byggeriet” på gaden. I brevet kan du blandt andet læse mere om relaterede afholdte og fremtidige aktiviteter samt delprojektet; Nedbringelse af sygefravær og forbedret produktivitet på arbejdspladsen.......Hermed er andet nyhedsbrev fra UCN Spireindsatsen ”Energieffektivisering af byggeriet” på gaden. I brevet kan du blandt andet læse mere om relaterede afholdte og fremtidige aktiviteter samt delprojektet; Nedbringelse af sygefravær og forbedret produktivitet på arbejdspladsen....

  19. 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...

  20. Centralisering overfor decentralisering af varelagre

    DEFF Research Database (Denmark)

    Graungaard Pedersen, Søren; Zachariassen, Frederik

    2010-01-01

    store virksomheder. I Danmark går langt størstedelen af virksomheder under betegnelsen små og mellemstore virksomheder (SMV) og for en stor andel af disse, er udfordringen med effektiv styring af varelagre også relevant. Denne artikel beskæftiger sig med udfordringen mellem centralisering overfor...... decentralisering af varelagre i SMV. Det viser sig, at der er betydelige forskelle i, hvilke argumenter der er for og imod, når udfordringen ses fra et SMV-perspektiv....

  1. 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

  2. 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.

  3. 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...

  4. Relevansen af Aristoteles' etik for konceptionen af eksistentiel terapi

    DEFF Research Database (Denmark)

    Dræby, Anders

    Siden sin undfangelse i begyndelsen af det 20. århundrede har den eksistentielle terapi repræsenteret et filosofisk funderet alternativ til de former for terapeutisk praksis, der er funderet i den funktionalistiske medicinske metafysik. Anvendelse af elementer fra Aristoteles' etik muliggør en...

  5. En systemteoretisk analyse af underviseres medlemskab af uddannelsessteder

    DEFF Research Database (Denmark)

    Kaspersen, Steffen Warming

    2014-01-01

    Afhandlingen undersøger ved hjælp af Niklas Luhmanns systemteori, hvordan undervisere på to uddannelsessteder der skal fusionere, er med til at bidrage til det nye uddannelsesstedets selvbeskrivelse. Der konkluderes, at undervisernes egen iagttagelse af uddannelsesstedet afgør hvilke faktorer der...

  6. 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”...

  7. Evaluering af lokale udviklingsprocesser

    DEFF Research Database (Denmark)

    Jensen, Bente

    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...... 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...... skitserer nogle perspektiverende overvejelser om de tre typer evalueringer anvendt i HPA-projektet....

  8. 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...

  9. Virkelighedsflugt og masser af sex

    DEFF Research Database (Denmark)

    Lorentzen, Rasmus Fink

    2011-01-01

    I artiklen laves en læsning af ungdomsromanen "6" (2010) af Ronni Andersen. Dernæst udfoldes en række litteraturpædagogiske forslag tilen undervisning i romanen i skolens ældste klasser. Arbejdsforslagene er baseret på en kompetencetilgang til danskfaget og rummer fire værksteder hvor eleverne sk...

  10. Midtvejsevaluering af Pulje til Landsbyfornyelse

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole; Blach, Vigdis E. Magnusdatter

    og bidrage til en helhedsorienteret og fremadrettet indsats i en række kommuner i de danske yderområder. Midtvejsevalueringen belyser effekten af puljen og kommunernes erfaringer med administrationen af puljen. Evalueringen er gennemført som en internet-baseret spørgeskemaundersøgelse (survey) blandt...

  11. 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...

  12. Tabet af en elsket person

    DEFF Research Database (Denmark)

    Spaten, Ole Michael; Kaldahl Friberg, Inge; Kyndesen, Anna Imer

    2011-01-01

    Psykologistudiet på Aalborg Universitet havde i samarbejde med Kræftens Bekæmpelse i Aalborg inviteret to af verdens absolutte topforskere indenfor moderne sorgteori til at forelæse og afholde workshop. Overskriften for heldagsaarangement fredag den 18. marts 2011 var "sorgen over tabet af den vi...

  13. Domesticeringen af Ford i Danmark

    DEFF Research Database (Denmark)

    Wagner, Michael

    Det amerikanske automobilfirma Ford Motor Company med hovedkvarter i Detroit begyndte at drive forretning i Danmark omkring 1906. De første aktiviteter blev konsolideret samme år ved udnævnelsen af motorforhandleren F. Bülow & Co. til salgsagent i Danmark og importør af Ford automobiler til det...

  14. På sporet af fremtidens konkurrenceevne

    DEFF Research Database (Denmark)

    Boje Rasmussen, Martin Møller

    2013-01-01

    økonomier. Formålet med udviklingen af indekset er at tilvejebringe et mere informeret og analytisk grundlag for at kickstarte den politiske debat om ikke blot, hvad lande skal leve af i fremtiden, men også hvad de skal leve for. På den måde giver SPI de politiske beslutningstagere et mere nuanceret og...

  15. Slutevaluering af TRIB-projektet

    DEFF Research Database (Denmark)

    Zobbe, Karen; Madsen, Lisbeth; Ertmann, Bo

    TRIB-projektet (Traumatiserede i beskæftigelse) er et udviklingsprojekt, som er finansieret af satspuljemidler under Ministeriet for Flygtninge, Indvandrere og Integration (INM). UC2, Videnscenter for tosprogethed og interkulturalitet, har stået for gennemførelse af projektet, som projektledelse....

  16. 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.)

  17. Anmeldelse af World Drug Report 2005

    DEFF Research Database (Denmark)

    Møller, Kim

    2005-01-01

    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......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...

  18. 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....

  19. 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....

  20. 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....

  1. 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.

  2. 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....

  3. 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...... iværksat en analyse af strategier for digitalisering af det eksisterende byggeri. I forbindelse hermed vil denne rapport undersøge problemerne og potentialerne ved at digitalisere den eksisterende bygningsmasse, både hvad angår hvilke dele heraf der er relevant at digitalisere, til hvilket niveau, samt de...

  4. 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....

  5. 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...

  6. 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....

  7. 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...

  8. 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.

  9. 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

  10. Techno-economic assessment of the need for bulk energy storage in low-carbon electricity systems with a focus on compressed air storage (CAES)

    Science.gov (United States)

    Safaei Mohamadabadi, Hossein

    Increasing electrification of the economy while decarbonizing the electricity supply is among the most effective strategies for cutting greenhouse gas (GHG) emissions in order to abate climate change. This thesis offers insights into the role of bulk energy storage (BES) systems to cut GHG emissions from the electricity sector. Wind and solar energies can supply large volumes of low-carbon electricity. Nevertheless, large penetration of these resources poses serious reliability concerns to the grid, mainly because of their intermittency. This thesis evaluates the performance of BES systems - especially compressed air energy storage (CAES) technology - for integration of wind energy from engineering and economic aspects. Analytical thermodynamic analysis of Distributed CAES (D-CAES) and Adiabatic CAES (A-CAES) suggest high roundtrip storage efficiencies ( 80% and 70%) compared to conventional CAES ( 50%). Using hydrogen to fuel CAES plants - instead of natural gas - yields a low overall efficiency ( 35%), despite its negligible GHG emissions. The techno-economic study of D-CAES shows that exporting compression heat to low-temperature loads (e.g. space heating) can enhance both the economic and emissions performance of compressed air storage plants. A case study for Alberta, Canada reveals that the abatement cost of replacing a conventional CAES with D-CAES plant practicing electricity arbitrage can be negative (-$40 per tCO2e, when the heat load is 50 km away from the air storage site). A green-field simulation finds that reducing the capital cost of BES - even drastically below current levels - does not substantially impact the cost of low-carbon electricity. At a 70% reduction in the GHG emissions intensity of the grid, gas turbines remain three times more cost-efficient in managing the wind variability compared to BES (in the best case and with a 15-minute resolution). Wind and solar thus, do not need to wait for availability of cheap BES systems to cost

  11. Salget af aktier i DONG

    DEFF Research Database (Denmark)

    Bechmann, Ken L.; Møller, Michael; Nielsen, Niels Christian

    2014-01-01

    Salget af en del af aktierne i DONG Energy har trukket store overskrifter den seneste tid i både ind- og udland og har haft betydelige politiske konsekvenser. Denne artikel behandler mange af de argumenter, der har været fremført for og imod salget. Samlet konkluderer artiklen, at debatten om sal...... salget til Goldman Sachs har været præget af misforståelser og forkerte argumenter. Omvendt er det også svært at se formålet med, at staten skal sælge på så komplicerede vilkår i stedet for selv at indskyde den manglende egenkapital....

  12. Potential of a hybrid wind-diesel-compressed air system for a remote telecommunication station : part 1; Potentiel d'un systeme hybride eolien-diesel-air comprime pour une station telecom isolee : partie 1

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H.; Dimitrova, M. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire LREE; Quebec Univ., Chicoutimi, PQ (Canada). Laboratoire LIMA; Chabour, H.; Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire LREE; Perron, J. [Quebec Univ., Chicoutimi, PQ (Canada). Laboratoire LIMA

    2009-07-01

    This paper reviewed the main characteristics of various electricity storage techniques and their potential for both long and short-term applications. In particular, it discussed the feasibility of using a hybrid wind-diesel-compressed air system to produce electricity at remote telecommunication stations. The hybrid system has been touted as a substitute for inefficient and costly diesel generators that contribute significant amounts of greenhouse gas to the atmosphere. Some low and high penetration wind-diesel hybrid systems have been studied in order to reduce the diesel consumption. This paper demonstrated that the use of a high penetration wind-diesel system together with compressed air energy storage (CAES) is a viable alternative to improve the overall percentage of renewable energy and reduce the cost of electricity in remote areas where a good wind resource is available. In part 1 of this study, the authors compared different technical solutions for the CAES system and described the one that optimizes the performance and the cost of the overall system. 3 figs.

  13. 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. ...

  14. 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.

  15. 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...

  16. 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...

  17. Overvejelser vedr. effektvurdering af det Digitale Sygehus

    DEFF Research Database (Denmark)

    Andersen, Povl Erik Rostgård; Wit, Camilla Kølsen de

    2001-01-01

    Nærværende skrift indeholder en beskrivelse af de overvejelser og planer, der er lavet på projektet 'Effektvurdering af Det Digitale Sygehus' medio dec. 2001.......Nærværende skrift indeholder en beskrivelse af de overvejelser og planer, der er lavet på projektet 'Effektvurdering af Det Digitale Sygehus' medio dec. 2001....

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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....

  3. Discussions on Energy Saving of Air-Cooled Compressed Air-Conditioning Unit%风冷压缩单元式空调器节能探讨

    Institute of Scientific and Technical Information of China (English)

    冯璐; 陆黎明

    2012-01-01

    Analyzes the operating principle of air-cooled air conditioner,put forward two types of modular units produced hot water and room refrigeration in order to increase the comprehensive usage efficiency of energy and conserve the building energy.%从分析风冷压缩单元式空调器的制冷原理入手,提出了两种空气源热泵热水模块+空气源压缩制冷模块机,为提高能源综合利用效率、节约建筑能耗提供了一定的实践思路。

  4. Betydningen af pesticider for forekomsten af vilde bier

    DEFF Research Database (Denmark)

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

    Både i Danmark og andre steder er der observeret en nedgang i de insekter, der bestøver landmandens afgrøder og de vilde planter. Tilbagegangen falder sammen med, at landbrugsdriften er blevet mere intensiv, og anvendelsen af pesticider er øget. Vi ved imidlertid ikke, hvilken rolle pesticiderne...... 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...

  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. 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...... produktionsfaciliteterne. Virksomhederne synes at være usikre på, hvordan man indfanger, overfører og udvikler tavs viden. Litteraturstudier understøtter konklusionen om, at der er behov for en mere systematisk metode til at overføre og udvikle viden for at sikre en accelereret ramp-up efter flytning af...

  10. 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.

  11. 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...

  12. 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...

  13. 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"...

  14. 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...

  15. 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)

  16. Implementering af drift i byggeri

    DEFF Research Database (Denmark)

    Damgaard, Torben; Erichsen, Pia Bruun

    På trods af, at der løbende er udgivet materiale der argumenterer for at tænke drift ind i byggeprocesser, er der problemer med, at det faktisk sker. Undersøgelser viser, at forskellige barrierer kan være årsag til problemerne. Disse barrierer kan opstilles inden for følgende kategorier: Projekt...... 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...

  17. Den gode facilitator af refleksionsarbejde

    DEFF Research Database (Denmark)

    Jørgensen, Pia

    2009-01-01

    tværfaglig lektorgruppe fra social og sundhedssektoren.’Learning by doing’, selvevaluering og sparring følger herefter som bud på, hvordan man kan leve op til de tilsyneladende ret utopiske krav til en god facilitator. At kunne skabe det tillidsfulde refleksionsrum og at kunne stille gode...... præsenteres i det følgende afsnit, og forfatteren argumenterer for begrebet facilitator af refleksionsarbejde. Herefter udfoldes rollen som facilitator ifølge Ghay og Lillyman. De har fokus på positive praksisoplevelser og tillidsfulde relationer. Gillie Boltons teoretiske og praktiske referenceramme...... for facilitatorrollen beskrives herefter. Bolton beskriver refleksionsarbejde som en fysisk (ikke ren kognitiv), passioneret (ikke ren intellektuel) kontekstbunden kunstnerisk proces, som kræver flair, stil og intuition. I de følgende afsnit beskrives den gode facilitator af refleksionsarbejde detaljeret af en...

  18. 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.                                                                                                              

  19. Styring af international transfer pricing

    DEFF Research Database (Denmark)

    Reuther, Peter; Rossing, Christian Plesner

    2011-01-01

    Nærværende artikel introducerer international transfer pricing, dels som et skatteretligt fænomen og dels som et værktøj til planlægning og økonomisk styring af koncernforbundne selskaber i en multinational virksomhed (MNV). Med udgangspunkt i en case-analyse af MNV’en gives der et konkret eksempel...... international transfer pricing i betragtning, når økonomiske styringssystemer i en MNV skal anvendes til planlægning og opfølgning....

  20. 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...

  1. På sporet af den tabte sans

    DEFF Research Database (Denmark)

    Nielsen, Thomas Rosendal

    2014-01-01

    Analyse af en workshop om interaktive strategier i børneteater for børn. Workshoppen fandt sted på Dramatikkens hus i Oslo og blev ledet af Sara Topsøe-Jensen, kunstneriske leder af teatret Carte Blanche.......Analyse af en workshop om interaktive strategier i børneteater for børn. Workshoppen fandt sted på Dramatikkens hus i Oslo og blev ledet af Sara Topsøe-Jensen, kunstneriske leder af teatret Carte Blanche....

  2. Fiktionen, der var ude af sig selv

    DEFF Research Database (Denmark)

    Hansen, Kim Toft

    2007-01-01

    På baggrund af en analyse af Lars Frosts roman Smukke biler efter krigen (2004) reflekterer jeg over fiktionen som på én gang selvberoende og selvnedbrydende størrelse, og der henvises til Adornos æstetik som en mulig teoretisk ramme for begribelsen af dette tilsyneladende paradoks.......På baggrund af en analyse af Lars Frosts roman Smukke biler efter krigen (2004) reflekterer jeg over fiktionen som på én gang selvberoende og selvnedbrydende størrelse, og der henvises til Adornos æstetik som en mulig teoretisk ramme for begribelsen af dette tilsyneladende paradoks....

  3. Elektrokemisk fjernelse af cadmium fra bioasker

    DEFF Research Database (Denmark)

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

    Posteren viser resultater fra elektrokemiske rensningsforsøg på bioasker udført i forbindelse med PSO projekt 5205 "Elektrokemisk fjernelse af cadmium fra bioasker i pilotskala og vurdering af mulighederne for nyttiggørelse af behandlet aske i beton".......Posteren viser resultater fra elektrokemiske rensningsforsøg på bioasker udført i forbindelse med PSO projekt 5205 "Elektrokemisk fjernelse af cadmium fra bioasker i pilotskala og vurdering af mulighederne for nyttiggørelse af behandlet aske i beton"....

  4. A Site Simulation Test on Compressed Air Blowers for Ash Fouling of Air Cooled Condensers%空冷凝汽器积灰干式吹扫系统现场实验研究

    Institute of Scientific and Technical Information of China (English)

    赵波; 马士全; 胡亚才; 杨善让; 张纲; 张宏宇; 张海林; 蒋静江; 刘志超; 王文忠; 洪海清

    2013-01-01

    直冷系统以节水率达69%~84%而在燃煤电站得到广泛应用。但在风沙大的干旱地区,若清洗不及时,空冷凝汽器则因积灰而使排汽背压升高8 kPa甚或以上,机组煤耗因而升高10~15 g/(kW⋅h),污染排放亦随之增大,而及时清洗所需的水资源又为环境所限。对此,该文设计了一种以压缩空气代替高压除盐水的干式吹扫系统,并在某600 MW直冷机组单排翅片管空冷凝汽器上进行了两种清洗方式的比较实验。文中介绍了干式吹扫系统的构成、实验内容及结果,拟定了吹扫效果评价方法,建立了灰垢热阻与排汽背压的定量关联,并据以比较了干式吹扫与水洗在同一清洗周期内累计清洗效果。结果表明:干式吹扫年节水量为1.47 kg/m2,累计平均背压降低1.7 kPa ,机组发电煤耗降低约2.5g/(kW⋅h),实现了节水、节能和减排共赢。%Direct air cooling (DAC) system has been widely applied in coal-fired power plants for its water-saving rate of 69%~84%. However, in arid regions with large sandstorm, the exhaust pressure of steam turbine will be raised by 8kPa or more because of the ash fouling of air cooled condenser (ACC). If it is not timely cleaned, the coal consumption of unit would elevate above 10~15 g/(kW⋅h) and the pollution emissions increases in the meantime. But the water consumption for timely cleaning is restricted by environmental conditions. To solve the incompatible contradiction, a novel compressed air blower (CAB) system was designed to clean the ash fouling for ACC in this paper, that is, the compressed air will entirely replace desalted water as cleaning medium for the new system. The main body of this paper includes the basic components of the CAB system, the content and results of a site simulation test (SST) for CAB under multi-operation conditions on an ACC of 600MW DAC unit, the blowing evaluation indexes proposed, and the quantitative correlation

  5. 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。

  6. 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 • ...

  7. Fluoridering af drikkevandet i Danmark?

    DEFF Research Database (Denmark)

    Arvin, Erik; Spliid, Henrik; Bruvo, M.;

    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...

  8. Ud af subsidie-sumpen

    DEFF Research Database (Denmark)

    Ingemann, Jan Holm

    2012-01-01

    Artiklen tager afsæt i, at subsidier hverken er i samfundets eller landbrugernes interesse. Subsidierne kapitaliseres i jordpriserne og medfører endvidere højere priser på landbrugets inputs. Da subsidierne blev indført, fik de daværende jordejere frit foræret en kapitalgevinst. Når subsidierne a...

  9. Virksomhedernes opfattelse af arbejdsmarkedets "restgrupper"

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt

    2010-01-01

    Artiklen beskriver, hvorledes danske arbejdsgivere opfatter ældre ledige, ledige indvandrere og ledige med lang forudgående ledighed. Det teoretiske udgangspunkt er, at arbejdsmarkedets fundamentale informationsproblemer fører til brug af statistisk diskrimination og frygt for «lemons». Analyserne...

  10. 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...

  11. 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...

  12. 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...

  13. Udredning af xerostomi og hyposalivation

    DEFF Research Database (Denmark)

    Pedersen, Anne Marie Lynge; Dynesen, Anja Weirsøe; Jensen, Siri Beier

    2011-01-01

    Mundtørhed kræver grundig undersøgelse Xerostomi er ofte associeret til betydelig nedsat spytsekretion, men kan forekomme, uden at der objektivt kan påvises nedsat spytsekretion. Udredning af patienter, som klager over mundtørhed, bør således altid inkludere en omhyggelig anamnese, en detaljeret ...

  14. Professionalisering af den eksterne ekspert

    DEFF Research Database (Denmark)

    Gottlieb, Susanne

    Masterafhandling, der bearbejder problemstillingen, som den eksterne ekspert kommer ud for, når han/hun skal bidragge til udvikling af uddannelsessystemet i et andet land. Afhandlingen har et pædagogisk-antropologisk udgangspunkt og tager udgangspunkt i et konkret udviklingsprojekt i Letland i pe...

  15. 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...

  16. 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"...

  17. 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.

  18. 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...

  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. 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 ...

  1. 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.

  2. 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....

  3. Udvikling af intelligent legepraksis i trampoliner

    DEFF Research Database (Denmark)

    Elbæk, Lars; Karoff, Helle Skovbjerg; Rytz Alison, Sigrid

    2012-01-01

    Den digitale dimension ved børns leg spiller en stadig stigende rolle. Denne har nu også fundet vej til legeredskaber og senest til udvikling af et digitalt koncept til en havetrampolin. I design af trampolinen blev anvendt forskellige børneprofiler og legetyper som inspiration i udvikling af de ...

  4. 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...

  5. 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...

  6. Energioptimering af bæredygtighedscertificeringsprocesserne

    DEFF Research Database (Denmark)

    Christensen, Dorthe Holmberg; Carlsen, Mads; Alon, Shlomo Nevo;

    2014-01-01

    Større fokus på bæredygtighedscertificeringer som DGNB har yderligere øget kompleksiteten af designet af bygninger. Introduktionen af teknologier som building information modelling (BIM) og proces metoder som integreret design proces (IDP) kan hjælpe med at reducere kompleksiteten og bedre...

  7. 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.

  8. 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.

  9. 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...

  10. Study and design of a hybrid wind-diesel-compressed air system for providing electricity to a remote telecommunication station; Etudes et conception d'un systeme hybride eolien-diesel-air comprime pour l'electrification d'une station de telecommunications isolee

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H.; Dimitrova, M. [TechnoCentre eolien Gaspesie-les Iles, Gaspe, PQ (Canada); Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada); Perron, J. [Quebec Univ., Chicoutimi, PQ (Canada)

    2010-07-01

    This poster reported on a study that examined the feasibility of using a hybrid wind-diesel-compressed air system to produce electricity at remote telecommunication stations. Low and high penetration wind-diesel hybrid systems were studied in order to reduce the diesel consumption. The use of a high penetration wind-diesel system together with compressed air energy storage (CAES) was shown to be a viable alternative to improve the overall percentage of renewable energy and reduce the cost of electricity in remote areas where a good wind resource is available. Different technical solutions for the CAES system were compared. refs., figs.

  11. Trafikanalyser af et net af letbaner og BRT i Hovedstaden

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker; Ingvardson, Jesper Bláfoss; Andersen, Jonas Lohmann Elkjær

    Denne rapport gennemgår et projekt for Region Hovedstaden, hvor letbanenet fra forårets opgave for Region Hovedstaden (Nielsen, Ingvardson & Andersen, 2013) blev detaljeret, viderebearbejdet og forbedret, hvorefter der er gennemført beregninger af forskellige varianter med OTM Trafikmodellen. Arb...... og sammenlignes med tidligere net og beregninger, der er blevet gennemført i Trængselskommissionens regi....

  12. 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.)

  13. 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...

  14. 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...... spilkoncept, hvor remediering og it-kompetencer inddrages som vigtige teoretiske faktorer. Undersøgelsesdesignet er rettet mod elever i Folkeskolen igennem brugen af fokusgruppeinterviews, og dataindsamlingen er foretaget med video. Eleverne udtrykker sig i undersøgelsen klart omkring konceptets...

  15. Shortage of compressed air is expensive. Low pressure for end customers reduces efficiency and extends processing time; Druckluftmangel ist teuer. Niedriger Druck am Endverbraucher mindert die Leistung und verlaengert die Bearbeitungszeit

    Energy Technology Data Exchange (ETDEWEB)

    Stapel, A.G.

    2002-04-02

    The efficiency of compressed air tools decreases distinctly at 0,5 bar under normal pressure. Lower efficiency of a tool extends the processing time and low pressure in distribution network rises up energy cost. [German] - Schon 0,5 bar unter Nenndruck sinkt die Leistungsfaehigkeit vieler Druckluftwerkzeuge deutlich. - Die geringere Leistung eines Werkzeuges verlaengert auch die Arbeitszeit. - Zu niedriger Druck im Netz fuehrt zu deutlich hoeheren Energiekosten. (orig.)

  16. Kvalitetssikring af Ul prober på baggrund af protokol til vurdering af tekniske fantom billeder

    DEFF Research Database (Denmark)

    Vernegreen, Susanne

    2013-01-01

    fordel sorteres fra i en revidering af protokollen. Jeg havde valgt at medtage dem, da de indgik i den oprindelige CIRS protokol, og det kan i en startfase være en fordel at have flere målinger at holde sig til. Min vurdering er dog at denne fordel ikke opvejer det øgede tidsforbrug. Der er dog nogle...... ikke muligt at undgå subjektivitet i forbindelse med måling og vurdering af de tekniske fantombilleder, da disse foretages manuelt. Det er derfor vigtigt at foretage flere målinger, og måske også oftere målinger end hvis målingerne var objektive. Flere og oftere målinger tager tid, og kan gå ud over...

  17. Trials of the use of high pressure compressed air for coal winning in soutirage faces. Final report; Ensayo de arranque de carbon con aire comprimido de alta presion en explotaciones por sutiraje. Informe final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The company Hullera Vasco Leones (HVL) is trying to improve the results of its exploitations by means of soutirage (sublevel caving), looking for maximum vertical concentration of the product. The limitation of the present systems necessitates the use of other methods of breaking the coal block. For this reason, a trial of the high pressure compressed air blasting (DACAP) technique would appear to be appropriate. This offers the outstanding advantage of increasing the height of the coal obtained by soutirage. HVL has divided the investigation into two stages. Firstly, to study the feasibility study recommended the use of the Competidora method, using the DACAP technique for the soutirage, duplicating the distance between sublevels. The foreseen improvements are a cost reduction of 17% and an output increase of almost 9%. The trial stage of this operation started in the first six months of 1992 and results were established in relation to: working variables optimization, improvements in production and productivity, a better percentage of coal recovery and cost reductions. This document summarises the work done and the results obtained from the project.

  18. 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)

  19. 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....

  20. Effekter af koordineret hjerneskaderehabilitering. Et systematisk litteraturreview

    DEFF Research Database (Denmark)

    Glintborg, Chalotte; Hansen, Tia G. B.

    Forskningsprojekt udvikler ny definition af begrebet koordination Som et led i forskningsprojektet ”Bio-psyko-sociale effekter af koordineret hjerneskaderehabilitering” er der udviklet en ny definition af koordinationsbegrebet. Forskningsprojektet ”Bio-psyko-sociale effekter af koordineret...... senhjerneskadeområdet – initiativer, der skal fremme en sammenhængende og helhedsorienteret rehabiliteringsindsats. Men hvad dækker begrebet koordination egentlig over? Det har et nyt forskningsprojekt set på og kommer med et bud på en ny definition. Dansk definition mangler Indholdet i koordination har været upræcist...... beskrevet. Der er ingen klar dansk definition af koordination. Begrebet bliver ofte brugt inkonsistent, og koordination er meget forskelligt tilrettelagt. Derfor kan man ikke generelt dokumentere, om koordinatorfunktioner er en sikker vej til forbedring af komplekse rehabiliteringsforløb. Sundhedsstyrelsen...

  1. 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...

  2. Danskernes brug af nyhedsmedier: et nyt landkort

    DEFF Research Database (Denmark)

    Schrøder, Kim Christian

    2010-01-01

    Artiklen fremlægger første del af en analyse, der på en ny måde kortlægger danskernes brug og oplevelse af nyheder i det medialiserede samfund, på tværs af de forskellige – traditionelle og digitale - medieplatforme og genrer. Teoretisk er undersøgelsen forankret i offentlighedsteorien og den beg...

  3. 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...

  4. Dimensionering af fortrængningsventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2000-01-01

    Lufthastigheden og temperaturfordelingen er væsentlige elementer i bestemmelsen af den termiske komfort i rum med fortrængningsventilation. Det er derfor vigtigt at fastlægge disse størrelser i selve designproceduren. Aalborg Universitet har udviklet en forenklet metode til bestemmelse af lufthas...... lufthastigheden i strømningen fra et vægmonteret armatur samt en metode til bestemmelse af den lodrette temperaturgradient i rummet....

  5. Metodebeskrivelse for evaluering af arkitektonisk kvalitet

    DEFF Research Database (Denmark)

    Beim, Anne

    2000-01-01

    Artiklen indgår i en større publikation som er en vejledning i evaluering af boligbebyggelsers standard og kvalitet. Vejledningen er bygget op over et evalueringskoncept, der primært er tilrettelagt med henblik på evaluering af (almene) boligbebyggelser og er udarbejdet til vurdering af 10...... forsøgsbyggerier inden for Erhvervsfremmestyrelsens og By - Boligministeriets udviklingsinitiativ ' Proces og Produktudvikling i byggeriet' - det såkaldte PPB- program....

  6. Konceptuelt design og udvikling af Intergomus

    DEFF Research Database (Denmark)

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

    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...

  7. 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.

  8. 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...

  9. 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...

  10. Dialogisk gruppecoaching – facilitering af ledelsesudvikling

    DEFF Research Database (Denmark)

    Alrø, Helle; Dahl, Poul Nørgård; Kloster, Per

    Dialogisk gruppecoaching – facilitering af ledelsesudvikling udspringer af et aktionsforskningsprojekt, som er gennemført i samarbejde mellem to forskere, to konsulenter og ledergrupperne på Ældreområdet i Ikast-Brande Kommune. Projektet har haft et dobbelt formål, nemlig at skabe udvikling og...... læring i ledergrupperne, og at skabe viden om disse udviklings- og læreprocesser. Vi har således været optaget af, hvordan dialogisk gruppecoaching kan facilitere ledelsesudvikling, og hvordan dialogisk coaching kan udvikles som coachingkoncept ift. grupper. Dialogisk gruppecoaching – facilitering af...

  11. Midler til lindring af mundtørhed og stimulation af spytsekretion

    DEFF Research Database (Denmark)

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

    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...

  12. 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...

  13. 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.

  14. 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)

  15. Effets d’une compression cochléaire et d’une sélectivité en fréquence réduites sur la discrimination de la hauteur de tons complexes

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Bianchi, Federica; Fereczkowski, Michal;

    2016-01-01

    Des études physiologiques ont montré qu’une perte auditive neurosensorielle (PANS) augmente l’amplitude de l’enveloppe temporelle du signal (ci-après, enveloppe) dans les fibres nerveuses auditives. La perception de la hauteur des tons complexes aux harmoniques non résolues reposant sur des...... effets d’une dégradation de sélectivité en fréquence et d’une perte de compression sont enfin pris en compte comme facteurs potentiels de l’augmentation de l’enveloppe dans un modèle simplifié de la périphérie auditive. Ces simulations suggèrent que la réduction de la compression cochléaire et l...

  16. 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...

  17. 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."...

  18. Kritikken af new public management er forfejlet

    DEFF Research Database (Denmark)

    Klausen, Kurt Klaudi

    2016-01-01

    kronikken adresserer og korrigerer den opfattelse at de nyliberalistiske reformer under betegnelsen NPM ikke har bidraget positivt til moderniseringen af den offentlige sektor.......kronikken adresserer og korrigerer den opfattelse at de nyliberalistiske reformer under betegnelsen NPM ikke har bidraget positivt til moderniseringen af den offentlige sektor....

  19. Cyberwarfares udfordringer af begrebet kritisk infrastruktur

    DEFF Research Database (Denmark)

    Lauta, Kristian Cedervall; Hoffmann, Rune; Struwe, Lars Bangert

    I dag er der en stigende bekymring for cyberwarfare eller cyberkriminalitet. Det skyldes, at det moderne samfund er komplekst og sårbart. Samfundet baserer sig på udbuddet af stadig flere funktioner, som bliver tiltagende avancerede og internt afhængige af hinanden. Systemet bliver herved så avan...

  20. Grønland stiger af havet

    DEFF Research Database (Denmark)

    Laursen, Steen; Khan, Shfaqat Abbas

    2012-01-01

    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....

  1. Økonomisk Vurdering af Arbejdsulykker

    DEFF Research Database (Denmark)

    Rikhardsson, Pall M.; Mogensen, Birgitte; Ravn, Birgitte

    Formålet med rapporten er at præsentere en metode og en brugsanvisning, der kan anvendes til registrering og kortlægning af økonomiske omkostninger/effekter ved arbejdsulykker (ulykkesomkostninger) samt en guideline til brug ved konkretisering af de mere uhåndgribelige afledte effekter, som disse...

  2. 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 gør...

  3. Manual reduktion af pattegrisedødelighed

    DEFF Research Database (Denmark)

    Bonde, Marianne; Serup, Tove

    svært at opretholde en målrettet indsats. Aarhus Universitet, Det Jordbrugsvidenskabelige Fakultet, Foulum har siden 2007 arbejdet på forskningsprojektet Reduceret pattegrisedødelighed og fravænningsdiarre. Et af produkterne fra dette projekt er denne manual for reduktion af pattegrisedødelighed...

  4. Grundtvigs nationalisme i lyset af nationalismeteori

    DEFF Research Database (Denmark)

    Böss/Bøss, Michael

    2013-01-01

    Artiklen demonstrerer potentilaet for forskningen i Grundtvigs forståelse af "folk" og "folkelighed" i lyset af de sidste årtiers forskning i nationsbegrebet og nationalisme. Grundtvigs diskurser om danskhed og fædreland holde op mod de dominerende teoretiske paradigmer og viser, hvordan revision...

  5. Tre generationer af Flow Injection Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Chomchoei, Roongrat; Long, Xiangbao

    2004-01-01

    Siden introduktionen af FIA har en række videreudviklinger resulteret i Sequential Injection Analysis (SIA) og senest i Lab-on-Valve (LOV)-metodikken. Her beskrives disse, og der gives eksempler på, hvordan metoderne kan bruges til at bestemme sporstofkoncentrationer af metaller i komplekse...

  6. Udvikling af pille-doserings teknologi

    DEFF Research Database (Denmark)

    Brændgaard, Rikke; Churchill, Inge-Lise; Bolvig Poulsen, Søren;

    2015-01-01

    Lab. X har i samarbejde med Brønderslev Kommune og Firmaet LT Automation i et idegenereringsforløb omhandlende viden om "pillens vej", indhentet viden om udfordringer og barrierer i forbindelse med udlevering af medicin fra apoteket til den afslutningsvis indtages af borgeren. Formålet med unders...

  7. 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...

  8. 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...

  9. 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...

  10. Deregulering af arbejdsretlige EU-direktiver

    DEFF Research Database (Denmark)

    Hasselbalch, Ole; Rønnow Bruun, Jørgen

    2013-01-01

    Europa-Kommissionen vil lette de ”reguleringsmæssige byrder” for små og mellemstore virksomheder (SMV). Langt hovedparten af de danske virksomheder er SMV´er. Konsekvenserne af initiativet kan derfor blive særdeles vidtgående på dansk grund. Artiklen drøfter, om det overhovedet er muligt i henhold...

  11. 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...

  12. 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 katego...... 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....

  13. Miljøvurdering af isoleringsmetoder

    DEFF Research Database (Denmark)

    Krogh, H.; Rasmussen, J.O.; Nielsen, P.A.

    Når man skal gennemføre miljørigtigt byggeri er det nødvendigt at have adgang til miljødata for materialerne der knytter sig til produktet gennem hele dets livsforløb. I denne rapport præsenteres kvantitative miljødata for fremstilling af isoleringsprodukter. Det drejer sig om løsfyldsproduklter ...... cellulosefibre, ruller og plader af hør samt produkter af perlite. Rapporten viser også, hvordan disse data kan benyttes til at beregne miljøbelastninger for hele bygningsdele. Desuden gives en kvantitativ vurdering af produkternes miljøpåvirkninger af indeklimaet og ved bortskaffelse...

  14. Om fortolkning af Bernerkonventionen. Er Bernerkonventionen et maksimalistisk instrument?

    DEFF Research Database (Denmark)

    Blomqvist, Jørgen

    2016-01-01

    Bernerkonventionens formålsbestemmelser analyseres i lyset af deres betydning for fortolkning af konventionen. Det konstateres, at konventionen ikke tilstræber det absolut maksimale niveau af beskyttelse....

  15. 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.

  16. Optimering af behandlingseffekten i akvakultur. Minimering af forbrug og udledning af hjælpestoffer

    DEFF Research Database (Denmark)

    Sortkjær, Ole; Henriksen, Niels Henrik; Demuth Heinecke, Rasmus;

    er 1/5 af, hvad der normalt anvendes. Brintoverilte omsættes hurtigt, så det er nødvendigt at supplere med brintoverilte under behandlingen i damme. Forsøg med biofilter viser, at formalin omsættes hurtigere, hvis det i forvejen har været eksponeret med formalin, og det skader ikke den mikrobielle...... behandlingstiden samtidig bliver forlænget, sådan som toksicitetstestene viser. For at bekæmpe fiskedræberen skal der behandles flere gange med nogle dages mellemrum, når dambruget er hårdt inficeret. I recirkulerende anlæg med biofilter er det nødvendigt at supplere med formalin for at holde koncentrationen under...

  17. Trykfald over en bed af fliskoks

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik Birk

    En (atmosfærisk) luftstrøm ledtes gennem en fast bed af delvist forgasset fliskoks med en binær partikelstørrelsesfordeling (8 og 16 mm). Under variation af størrelsesfordeling og strømningshastighed registreredes det resulterende trykfald gennem bedden. Eksisterende estimationsformler for trykfa......En (atmosfærisk) luftstrøm ledtes gennem en fast bed af delvist forgasset fliskoks med en binær partikelstørrelsesfordeling (8 og 16 mm). Under variation af størrelsesfordeling og strømningshastighed registreredes det resulterende trykfald gennem bedden. Eksisterende estimationsformler...... for trykfaldet blev valideret for de givne kokspartikler. Note: Dette er en bearbejdning af rapporten “Trykfald over en Bed af Fliskoks” ved Donovan og Hindsgaul 1997 [1]. I nogle tilfælde er brugen af symboler ændret i forhold til rapporten for at opnå bedre konsistens ligesom fundne fejl er rettet. Både den...

  18. 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。

  19. Process for regeneration of a soot particle filter situated in the exhaust pipe of an air-compressing internal combustion engine. Verfahren zur Regeneration eines in der Abgasleitung einer luftverdichtenden Brennkraftmaschine angeordneten Russpartikelfilters

    Energy Technology Data Exchange (ETDEWEB)

    Abthoff, J.; Schuster, H.D.; Langer, H.J.; Strohmer, E.; Gabler, R.; Schulte, R.

    1991-05-08

    A process for the regenration of a soot particle filter situated in the exhaust pipe of an air-compressing injection internal combustion engine by burning off the soot particles is described. A device to control the suction pipe cross section depending on the load and speed is provided in the suction pipe. To prevent damage to the soot filter when changing to thrust operation of the internal combustion engine, it is proposed to move the device to control the suction air pipe cross section directly after a change to thrust operation of the internal combustion engine to a position reducing the pipe crosss ection to a minimum and then to move it continuously to its open position.

  20. Compressed gas fuel storage system

    Energy Technology Data Exchange (ETDEWEB)

    Wozniak, John J. (Columbia, MD); Tiller, Dale B. (Lincoln, NE); Wienhold, Paul D. (Baltimore, MD); Hildebrand, Richard J. (Edgemere, MD)

    2001-01-01

    A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

  1. Design of Marine Compressed Air Operation Training System with Virtual and Physical Combination%一种虚实结合的船舶压缩空气操作训练系统设计

    Institute of Scientific and Technical Information of China (English)

    邹文俊; 林洪贵; 孙美娜

    2015-01-01

    Marine power plant operation training system in shipping colleges has the disadvantages of large area, the high cost and the lack of real ship environment. Aimed at this problem,and taking marine compressed air system as an example, a combination of virtual and physical marine power plant operation training system is designed. The scene roaming and virtual operation function of the marine compressed air system is realized by Unity3D, the control task of the air compressor is completed by PLC control technology, and the problem of data communication between PLC Controllers and Unity3D is solved. Finally, the paper achieves the purpose of controlling the virtual air compressor through the physical control box.%针对航运院校采用真实船舶动力设备系统操作训练存在占地面积大、成本高且缺少实船环境的缺点,本文以船舶压缩空气系统为例设计出一种虚实结实的动力设备操作训练系统,建立了压缩空气系统的三维实体模型和设备的数学模型,通过 Unity3D 实现了船舶压缩空气系统的场景漫游和虚拟操作功能,采用PLC控制技术实现了空压机组的控制功能,解决了PLC控制器与Unity3D之间数据交互问题,最终实现了通过实物控制箱控制虚拟的空压机组的目的.

  2. 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....

  3. 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.

  4. Optimering af byggeprocessen via bedre/forøget brug af digitale modeller

    DEFF Research Database (Denmark)

    Carlsen, Mads; Grøn, Dorte Marie Frilund; Alon, Nevo;

    2013-01-01

    Projektet klarlægger nødvendigheden for, og muligheder i, en struktureret og konsekvent planlægning ved anvendelsen af BIM i relation til projektering, udførelse og drift af byggeri. Der er udarbejdet et planlægningsværktøj, der muliggør en sådan planlægning. Samtidig kortlægges de nødvendige data......, der kan udtrækkes af en BIM model ved gennemførelsen af en LCA simulering. Projektet afsluttes med en præsentation af en udviklet demonstratorapplikation til gennemførelse af LCA simuleringer koblet med BIM modellen....

  5. 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

  6. Partial transparency of compressed wood

    Science.gov (United States)

    Sugimoto, Hiroyuki; Sugimori, Masatoshi

    2016-05-01

    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  7. 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.

  8. 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...

  9. 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...... BYG-DTU som den primært udførende part. Projektets formål var at undersøge, om den elektrodialytiske rensningsmetode kunne bruges til at reducere indholdet af cadmium i asker fra biobrændsel (f.eks. træflis og halm) med henblik på nyttiggørelse af askerne. Projektet havde nær sammenhæng med det...

  10. 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.

  11. Arbejdsmiljø ved udbud af busdrift

    DEFF Research Database (Denmark)

    Wiegmann, Inger-Marie; Mathiesen, Karin; Hasle, Peter

    En undersøgelse af sammenhængen mellem arbejdsmiljø og udbud af busdrift i tre trafikselskabet. Resultaterne peger på at arbejdsmiljøet går fra udelukkende til at være et anliggende mellem arbejdsgiver og arbejdstager til et trepartsforhold hvor også udbyder (trafikselskabet) får et ansvar og har...

  12. 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....

  13. 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

  14. 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....

  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. 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...

  17. 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...... internetsøgestrategi til fund af ny medicinsk teknologi til behandling af lokaliseret prostatacancer. Materiale og metoder: Websider blev fundet ved hjælp af litteratursøgning og søgning i specielt udvalgte kilder på internettet. In- og eksklusionskriterier blev udviklet på basis af litteratur og anvendt på en række...... potentielt relevante sider. En foreløbig søgestrategi blev udviklet, teknologier blev identificeret, nyhed og relevans af disse blev vurderet af urologer i teamet, og information herfra blev brugt til at justere strategien. Seks urologer testede strategien, og deres fund blev brugt til at opstille rækken af...

  18. Første generation af miljøvurdering af kommune- og lokalplaner

    DEFF Research Database (Denmark)

    Larsen, A.; Lyhne, I.; Kristensen, J.N.;

    2006-01-01

    Artiklen præsenterer den første statusopgørelse på kommunernes arbejde med Lov om miljøvurdering af planer og programmer (SMV) og er den første empiriske undersøgelse af, hvad loven betyder for kommunernes planlægning.......Artiklen præsenterer den første statusopgørelse på kommunernes arbejde med Lov om miljøvurdering af planer og programmer (SMV) og er den første empiriske undersøgelse af, hvad loven betyder for kommunernes planlægning....

  19. 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...

  20. 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....

  1. 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.

  2. 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...

  3. 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...

  4. 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...

  5. Tællinger af vandfugle i Danmark 1998-99

    DEFF Research Database (Denmark)

    Pihl, S.; Laubek, B.

    1999-01-01

    Skallingen. Der registreres også vandstand, saltholdighed og drift af området. Desuden følges bunddyrene i fjorden og orkidéer på engene. Langli ligger i den nordlige del af Vadehavet. Øen med omgivende vandarealer blev fredet i 1982, hvor observationer af fuglene også startede. Reservatet, der er en del af...

  6. Overvågning af karplanter i Suserup Skov

    DEFF Research Database (Denmark)

    Wind, P.

    1999-01-01

    Skallingen. Der registreres også vandstand, saltholdighed og drift af området. Desuden følges bunddyrene i fjorden og orkidéer på engene. Langli ligger i den nordlige del af Vadehavet. Øen med omgivende vandarealer blev fredet i 1982, hvor observationer af fuglene også startede. Reservatet, der er en del af...

  7. Produktudvikling af fødevarer med Quality Function Deployment

    DEFF Research Database (Denmark)

    Bech, Anne C.

    1998-01-01

    Produktudvikling af fødevarer stiller stadig større krav til virksomhedernes kompetencer. QFD filosofien kan bidrage til at skabe en fælles forståelse af grundlaget for udvikling af nye produkter. Udgangspunktet er en forståelse af forbrugernes behov i relation til virksomhedens muligheder, heref...

  8. 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...

  9. 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"...

  10. Implementering og anvendelse af nyere ledelsesteknologier i den kommunale sektor

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Christian

    2009-01-01

    New Public Management vedrører transformeringen af ledelse i den offentlige sektor, bl.a. ved introduktion af nye krav til de offentlige ledere, herunder at skulle stå til regnskab for ressourceforbrug, kvaliteten af de leverede ydelser, samt en fornuftig anvendelse af skatteborgernes penge. En c...

  11. Udvikling af informationskompetence i problemorienterede læreprocesser

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...

  12. 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...

  13. 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)

  14. 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...

  15. 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 ...

  16. 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...

  17. Modellering af naturlig ventilation og natkøling- ved hjælp af ringmetoden

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund

    De seneste årtiers fokusering på energieffektivitet og indeklima har betydet en genopfindelse af naturlig ventilation. Dagens byggeskik og fremkomsten af computeren har betydet at der har været og stadig er et stort behov for beregningsmodeller der hurtigt og præcist kan beregne konsekvenserne ve...

  18. Fermentering af korn øger fordøjeligheden af næringsstoffer

    DEFF Research Database (Denmark)

    Pedersen, Anni Øyan; Jørgensen, Henry; Bach Knudsen, Knud Erik;

    2010-01-01

    foderblandingerne med ikke-fermentet korn var dog lavere end normalt, hvilket kan have påvirket resultaterne, så effekten af fermentering er større i dette forsøg, end hvad der normalt kan forventes. Kornet var groft formalet (ca. 30 % under 1 mm), hvilket kan have påvirket resultaterne. Ved finere formaling af...

  19. 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...

  20. 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...

  1. Bestemmelse af spormetaller i organisk materiale

    DEFF Research Database (Denmark)

    Tjell, Jens Christian; Palfeldt, Kirsten

    Behovet for pålidelige analysemetoder til bestemmelse af spormetalindhold i organiske materialer, f.eks. planter, slam og dyrevæv er stigende på grund af den stigende erkendelse af disse stoffers betydning for organismers fysiologi, både hvor disse stoffer optræder i uønskede koncentrationer som...... der over de sidste år udviklet en analyseprocedure hvorefter det er muligt at analysere for metallerne Mn, Cu, Ni, Co, Cr, Zn, Cd og Pb i planter, dyrevæv, jord, slam og andre materialer med standardafvigelser på mellem 5 og 10%. Der gøres rede for denne metode....

  2. Medieleg af 1. og 2. grad

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    2009-01-01

    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 ydre iagttagere og [...] for selviagttagelse" (Luhmann 1997, p.46). I denne artikels kontekst, kan denne systemiske opfattelse af leg ses i sammenhæng med Gregory Batesons legeteori, hvor det at lege indebærer en evne til at etablere en særlig referenceramme, indenfor hvilken de handlinger, der udføres...

  3. Energimæssig helhedsvurdering af vinduer

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    , hvor der kan findes et optimum for g-værdien. Størrelsen afhænger af den aktuelle vinduesfordeling på de fire verdenshjørner. Installation af køleanlæg kan undgås ved at anvende solafskærmende ruder, men energimæssigt og komfortmæssigt er de to løsninger omtrent ligeværdige på grund af, at solindfaldet......, så de begyndende overtemperaturer imødegås fra start. U-værdien for ramme/karmkonstruktionen har i Danmark ikke fulgt med udviklingen på rudeområdet, mens der i Tyskland er udviklet isolerende ramme/karmkonstruktioner i forbindelse med det såkaldte ”Passiv Haus” koncept. Herhjemme er de fleste forsøg...

  4. 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...

  5. 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...

  6. Ingen gavnlige virkninger af tilskud med antioxidanter

    DEFF Research Database (Denmark)

    Skibsted, Leif Horsfelt; Jørgensen, Karina

    2006-01-01

    Ifølge motions- og ernæringsrådets nyeste rapport er der ikke videnskabeligt belæg for, at tilskud af antioxidanter reducrerer risikoen for sygdomme. Samtidig frarådes danskerne at indtage store mængder E-vitamin og beta-karoten.......Ifølge motions- og ernæringsrådets nyeste rapport er der ikke videnskabeligt belæg for, at tilskud af antioxidanter reducrerer risikoen for sygdomme. Samtidig frarådes danskerne at indtage store mængder E-vitamin og beta-karoten....

  7. Ingen gavnlige virkninger af tilskud med antioxidanter

    DEFF Research Database (Denmark)

    Skibsted, Leif Horsfelt; Jørgensen, Karina

    2006-01-01

    Ifølge Motions- og Ernæringsrådets nyeste rqapport er der ikke videnskabeligt belæg for at tilskud af antioxidanter reducerer risikoen for sygdomme. Samtidig frarådes danskerne at indtage store doser E-vitamin og beta-karoten.......Ifølge Motions- og Ernæringsrådets nyeste rqapport er der ikke videnskabeligt belæg for at tilskud af antioxidanter reducerer risikoen for sygdomme. Samtidig frarådes danskerne at indtage store doser E-vitamin og beta-karoten....

  8. Lovbestemt delegation af forvaltningsvirksomhed til private

    DEFF Research Database (Denmark)

    Bønsing, Sten

    2013-01-01

    Forvaltningsretten regulerer forvaltningsmyndigheder, når disse udøver forvaltningsvirksomhed. I nogle tilfælde bestemmes det ved lov, at private skal udføre forvaltningsvirksomhed. Dette betyder imidlertid ikke, at forvaltningsretten samtidig automatisk følger med. Artiklen analyserer, hvordan...... forvaltningsvirksomhed udøves af private på grundlag af lov, og konstaterer, at forvaltningsretten kun i begrænset omfang sikrer borgernes retsstilling, når der træffes afgørelser mv. Retsstillingen kritiseres, og der angives forslag til, hvordan forvaltningsretten kan komme tilbage på banen, når private træffer...

  9. 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...

  10. Kvantitativ delevaluering af Stofrådgivningen

    DEFF Research Database (Denmark)

    Frederiksen, Kirsten Søndergaard; Ravn, Signe

    Opsummering for Stofrådgivningsrapport Stofrådgivningen bad i foråret 2012 Center for Rusmiddelforskning, Aarhus Universitet, om at gennemføre en evaluering af stedets behandlingstilbud ved hjælp af to delundersøgelser, en kvalitativ og en kvantitativ. Den kvalitative delundersøgelse omfattede...... problemer såsom markante koncentrationsproblemer, depressive tanker og egentlige psykiatriske diagnoser. Rapporten viser, at der sker positive udviklinger for de unges stofforbrug under et behandlingsforløb ved Stofrådgivningen. Desuden sker der særligt en positiv udvikling i forhold til de unges...

  11. 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....

  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. Ajourføring af ISA 610

    DEFF Research Database (Denmark)

    Fabricius, Ole; Kiertzner, Lars

    2011-01-01

    Ajourføringen af ISA 610 indebærer generelle skærpelser i relation til den eksterne revisors risikovurderingshandlinger i forhold til intern revision samt til ekstern revisors revisionshandlinger på områder med væsentlig risiko og skønsmæssig usikkerhed.......Ajourføringen af ISA 610 indebærer generelle skærpelser i relation til den eksterne revisors risikovurderingshandlinger i forhold til intern revision samt til ekstern revisors revisionshandlinger på områder med væsentlig risiko og skønsmæssig usikkerhed....

  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. 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.  ...

  16. 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 danske...

  17. 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;

    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 være lakeret på matkontaktsiden med epoxylakker fremstillet af monomererne epichlorhydrin og bisphenol A. Alle...... 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...

  18. 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....

  19. Brugen af Geografiske Informationssystemer til effektundersøgelse af Intelligent Farttilpasning i Danmark

    DEFF Research Database (Denmark)

    Agerholm, Niels; Tradisauskas, Nerius; Bolet, Lars;

    2012-01-01

    Geografiske Informationssystemer er anvendt til at dels at dokumentere, hvilke effekter Intelligent Farttilpasning har på hastighedsoverskridelser, og dels til at undersøge, hvordan disse overskridelser kan præsenteres meningsfuldt i spatiale analyser. Analyser af effekten på kørselsadfærden er...... foretaget for ti af de deltagende bilister i et nordjysk Intelligent Fartilpasningsforsøg for unge bilister. Hovedresultaterne er, at Intelligent Farttilpasning nedbringer både størrelsen af hastighedsoverskridelser og længden på disse. Uden Intelligent Farttilpasning blev der især kørt for hurtigt på lange...

  20. 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...