WorldWideScience

Sample records for thermosyphon system analise

  1. Analysis of a solar water thermosyphon system; Analise do aquecimento solar de agua por sistema a termosifao

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Abner Barzola

    1992-07-01

    A design methodology and to perform the simulation of flat plate solar collectors coupled with a water storage tank and operating by natural convection circulation is presented. For a given site the incident solar radiation on a tilted and previously oriented surface is determined from solar astronomy and the dally average of the monthly data of the horizontal total solar radiation. Huancayo situated in Peru (at 12.05 deg S, long. 76.18 deg W, altitude 3,312 m), is chosen as the site to be installed the solar water system, as a mean to improve the peasant's standard of life. An optimum tilt angle for a north oriented collector surface is obtained in order to have a maximum solar capture during the water. The theoretical methodology use here is based upon the ONG's paper (1976), and in attrition is considered the hot water drainage due to the dally consumption. For the sake of comparison, the calculated flowrate values are confronted with the experimental data obtained by FERNANDEZ, for a same site location (Rio de Janeiro) and are used identical dimensions for the water thermosyphon heater. Finally, the economic feasibility of the solar water system is demonstrated when it is compared with the usual immersion electric resistance boiler. For the Peruvian conditions the more adequate solar water system for a rural or domestic usage is a 1.4 m{sup 2} area solar collector (6 parallel, 15,875 mm copper tubes), 100 l capacity for the water storage tank, 33.5 mm for the connecting tubes, being of 300 mm. The height between the collector top and the bottom of the tank. (author)

  2. Analysis of a solar water thermosyphon system; Analise do aquecimento solar de agua por sistema a termosifao

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Abner Barzola

    1992-07-01

    A design methodology and to perform the simulation of flat plate solar collectors coupled with a water storage tank and operating by natural convection circulation is presented. For a given site the incident solar radiation on a tilted and previously oriented surface is determined from solar astronomy and the dally average of the monthly data of the horizontal total solar radiation. Huancayo situated in Peru (at 12.05 deg S, long. 76.18 deg W, altitude 3,312 m), is chosen as the site to be installed the solar water system, as a mean to improve the peasant's standard of life. An optimum tilt angle for a north oriented collector surface is obtained in order to have a maximum solar capture during the water. The theoretical methodology use here is based upon the ONG's paper (1976), and in attrition is considered the hot water drainage due to the dally consumption. For the sake of comparison, the calculated flowrate values are confronted with the experimental data obtained by FERNANDEZ, for a same site location (Rio de Janeiro) and are used identical dimensions for the water thermosyphon heater. Finally, the economic feasibility of the solar water system is demonstrated when it is compared with the usual immersion electric resistance boiler. For the Peruvian conditions the more adequate solar water system for a rural or domestic usage is a 1.4 m{sup 2} area solar collector (6 parallel, 15,875 mm copper tubes), 100 l capacity for the water storage tank, 33.5 mm for the connecting tubes, being of 300 mm. The height between the collector top and the bottom of the tank. (author)

  3. A numerical study of boiling flow instability of a reactor thermosyphon system

    International Nuclear Information System (INIS)

    Nayak, A.K.; Lathouwers, D.; Hagen, T.H.J.J. van der; Schrauwen, Frans; Molenaar, Peter; Rogers, Andrew

    2006-01-01

    A numerical study has been carried out to investigate the boiling flow instability of a reactor thermosyphon system. The numerical model solves the conservation equations of mass, momentum and energy applicable to a two-fluid and three-field steam-water system using a finite difference technique. The computer code MONA was used for this purpose. The code was applied to the thermosyphon system of an EO (ethylene oxide) chemical reactor in which the heat released by a catalytic reaction is carried by boiling water under natural circulation conditions. The steady-state characteristics of the reactor thermosyphon system were predicted using the MONA code and conventional two-phase flow models in order to understand the model applicability for this type of thermosyphon system. The two-fluid model was found to predict the flow closest to the measured value of the plant. The stability behaviour of the thermosyphon system was investigated for a wide range of operating conditions. The effects of power, subcooling, riser length and riser diameter on the boiling flow instability were determined. The system was found to be unstable at higher power conditions which is typical for a Type II instability. However, with an increase in riser diameter, oscillations at low power were observed as well. These are classified as Type I instabilities. Stability maps were predicted for both Type I and Type II instabilities. Methods of improving the stability of the system are discussed

  4. A numerical study of boiling flow instability of a reactor thermosyphon system

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, A.K.; Lathouwers, D.; Hagen, T.H.J.J. van der [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Schrauwen, Frans; Molenaar, Peter; Rogers, Andrew [Shell Research and Technology Centre, Badhuisweg 3, 1031 CM Amsterdam (Netherlands)

    2006-04-01

    A numerical study has been carried out to investigate the boiling flow instability of a reactor thermosyphon system. The numerical model solves the conservation equations of mass, momentum and energy applicable to a two-fluid and three-field steam-water system using a finite difference technique. The computer code MONA was used for this purpose. The code was applied to the thermosyphon system of an EO (ethylene oxide) chemical reactor in which the heat released by a catalytic reaction is carried by boiling water under natural circulation conditions. The steady-state characteristics of the reactor thermosyphon system were predicted using the MONA code and conventional two-phase flow models in order to understand the model applicability for this type of thermosyphon system. The two-fluid model was found to predict the flow closest to the measured value of the plant. The stability behaviour of the thermosyphon system was investigated for a wide range of operating conditions. The effects of power, subcooling, riser length and riser diameter on the boiling flow instability were determined. The system was found to be unstable at higher power conditions which is typical for a Type II instability. However, with an increase in riser diameter, oscillations at low power were observed as well. These are classified as Type I instabilities. Stability maps were predicted for both Type I and Type II instabilities. Methods of improving the stability of the system are discussed. [Author].

  5. Design of passive decay heat removal system using thermosyphon for low temperature and low pressure pool type LWR

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jangsik; You, Byung Hyun; Jung, Yong Hun; Jeong, Yong Hoon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    In seawater desalination process which doesn't need high temperature steam, the reactor has profitability. KAIST has be developing the new reactor design, AHR400, for only desalination. For maximizing safety, the reactor requires passive decay heat removal system. In many nuclear reactors, DHR system is loop form. The DHR system can be designed simple by applying conventional thermosyphon, which is fully passive device, shows high heat transfer performance and simple structure. DHR system utilizes conventional thermosyphon and its heat transfer characteristics are analyzed for AHR400. For maximizing safety of the reactor, passive decay heat removal system are prepared. Thermosyphon is useful device for DHR system of low pressure and low temperature pool type reactor. Thermosyphon is operated fully passive and has simple structure. Bundle of thermosyphon get the goal to prohibit boiling in reactor and high pressure in reactor vessel.

  6. Design of Passive Decay Heat Removal System using Mercury Thermosyphon for SFR

    Energy Technology Data Exchange (ETDEWEB)

    You, Byung Hyun; Jeong, Yong Hoon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    In this study, thermosyphon application is suggested to accomplish the fully passive safety grade system and compactness of components via enhance the heat removal performance. A two-phase evaporating thermosyphon operates when the evaporator is heated, the working fluid start boiling, the vapor that is formed moves to the condenser, where it is condensed on the walls, giving up the heat of phase change to the cooling fluid. Gravity forces cause the condensate to condensed liquid flow to the evaporator again. These processes occur continuously, which causes transfer of heat from evaporator to condenser vice versa. After the thermal design and performance evaluation, the results were compared with the performance of conventional DRACS system. For the same amount of decay heat removal performance of PDRC system of KALIMER-600 mercury thermosyphon system can archive around 30∼50% of compactness. For the detailed design, improved analytical model and experimental data for the validation will be required to specify the new DHR system.

  7. Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Tae [Kongju National Univ., Kongju (Korea, Republic of); Song, Kyu Sub [Electronics and Telecommunications Research Institute, Taejon (Korea, Republic of); Lee, Young [Univ. of Ottawa, Ontario (Canada)

    1998-10-01

    A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm{sup 2}. The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm{sup 2} with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion.

  8. Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

    International Nuclear Information System (INIS)

    Kim, Won Tae; Song, Kyu Sub; Lee, Young

    1998-01-01

    A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm 2 . The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm 2 with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion

  9. Investigation and Construction of a Thermosyphoning Solar Hot Water System

    Science.gov (United States)

    Johnson, Harvey

    1978-01-01

    Describes how a thermosyphoning solar water heater capable of heating 110 kilogram of water to 80 degree Celsius and maintaining this temperature for 24 hours was constructed by four students in the fifth form of Sekolah Date Abdul Razak, Seremban, Malaysia in 1976. (HM)

  10. The Opportunity Analyses of Using Thermosyphons in Cooling Systems of Power Transformers on Thermal Stations

    Directory of Open Access Journals (Sweden)

    Nurpeiis Аtlant

    2016-01-01

    Full Text Available The opportunity analyses of using the thermosyphons as the main elements in the systems of thermal regime supplying has been conducted under the conditions of their usage in power transformers on thermal stations. Mathematical modeling of jointly proceeding processes of conduction, forced convection and phase transitions (evaporation and condensation of coolant in the thermosyphon of rectangular cross section has been carried out. The problem of conjugated conductive-convective heat transfer was formulated in dimensionless variables “vorticity/stream function/temperature” and solved by finite difference method. The effect of the heat flux density supplied to the bottom cover of the thermosyphon from a transformer tank on the temperature drop in the steam channel was shown based on the analysis of numerical simulation results (temperature fields and velocities of steam. The parameters of energy-saturated equipment of thermal stations were found to be controlled by an intensification of heat removal from the top cover surface of the thermosyphon.

  11. Comparison of simulated and experimental results of temperature distribution in a closed two-phase thermosyphon cooling system

    Science.gov (United States)

    Shaanika, E.; Yamaguchi, K.; Miki, M.; Ida, T.; Izumi, M.; Murase, Y.; Oryu, T.; Yanamoto, T.

    2017-12-01

    Superconducting generators offer numerous advantages over conventional generators of the same rating. They are lighter, smaller and more efficient. Amongst a host of methods for cooling HTS machinery, thermosyphon-based cooling systems have been employed due to their high heat transfer rate and near-isothermal operating characteristics associated with them. To use them optimally, it is essential to study thermal characteristics of these cryogenic thermosyphons. To this end, a stand-alone neon thermosyphon cooling system with a topology resembling an HTS rotating machine was studied. Heat load tests were conducted on the neon thermosyphon cooling system by applying a series of heat loads to the evaporator at different filling ratios. The temperature at selected points of evaporator, adiabatic tube and condenser as well as total heat leak were measured. A further study involving a computer thermal model was conducted to gain further insight into the estimated temperature distribution of thermosyphon components and heat leak of the cooling system. The model employed boundary conditions from data of heat load tests. This work presents a comparison between estimated (by model) and experimental (measured) temperature distribution in a two-phase cryogenic thermosyphon cooling system. The simulation results of temperature distribution and heat leak compared generally well with experimental data.

  12. Study on the Operating Characteristics and System Modelling of Loop type Thermosyphon for Using Solar Thermal Energy

    International Nuclear Information System (INIS)

    Kang, Myeong Cheol

    1999-02-01

    Solar energy is one of the promising resources of renewable energy. It is of particular interest due to the energy shortage and environment pollution problems. Water heating by solar energy for domestic use is one of the most successful and feasible applications of solar energy. The thermosyphon SDHWS and the loop type thermosyphon systems are widely used for domestic hot water system. The loop type thermosyphon is a circulation device for transferring the heat produced at the evaporator area to the condenser area in the loop by a working fluid. The system has the advantage of high heat transfer rate. A phase change of the working fluid occurs at the evaporator section and the vapor is transported to the condenser by the density gradient. The loop type thermosyphon collector can be made of smaller area and has higher efficiency than the present thermosyphon SDHWS. In this study, the operating characteristics of various working fluids being used have been identified. The working fluids employed in the study were ethanol, water and a binary mixture of ethanol and water. The volume of working fluid used in this study were 30%, 40%, 50%, 60% and 70% of evaporator volume. An increased heat was applied with the increased volume of working fluid. It is observed that, in the thermosyphon with low volume of working fluid, such as 30% or 40%, the fluid was dried out. The average efficiency of the loop type thermosyphon was 46% with high solar irradiation and 43% with low irradiation. The flow pattern and mechanism of the heat transfer were identified through this study. Flow patterns of the binary mixture working fluid were also investigated, and the patterns were recorded in the camera. The system parameters were calculated using the thermal performance data. Modelling of the system was carried out using PSTAR method and TRNSYS program

  13. Loop thermosyphon thermal management of the avionics of an in-flight entertainment system

    International Nuclear Information System (INIS)

    Sarno, C.; Tantolin, C.; Hodot, R.; Maydanik, Yu.; Vershinin, S.

    2013-01-01

    A new generation of in-flight entertainment systems (IFEs) used on board commercial aircrafts is required to provide more and more services (audio, video, internet, multimedia, phone, etc.). But, unlike other avionics systems most of the IFE equipment and boxes are installed inside the cabin and they are not connected to the aircraft cooling system. The most critical equipment of the IFE system is a seat electronic box (SEB) installed under each passenger seat. Fans are necessary to face the increasing power dissipation. But this traditional approach has some drawbacks: extra cost multiplied by the seat number, reliability and maintenance. The objective of this work is to develop and evaluate an alternative completely passive cooling system (PCS) based on a two-phase technology including heat pipes and loop thermosyphons (LTSs) adequately integrated inside the seat structure and using the benefit of the seat frame as a heat sink. Previous works have been performed to evaluate these passive cooling systems which were based on loop heat pipe. This paper presents results of thermal tests of a passive cooling system of the SEB consisting of two LTSs and R141b as a working fluid. These tests have been carried out at different tilt angles and heat loads from 10 to 100 W. It has been shown that the cooled object temperature does not exceed the maximum given value in the range of tilt angles ±20° which is more wider than the range which is typical for ordinary evolution of passenger aircrafts. -- Highlights: ► A passive cooling system has been developed for avionics application. ► The system consists of loop thermosyphons and a passenger seat as a heat sink. ► Successful system tests have been run at heat loads to 100 W and angle tilts to 20°

  14. Thermosyphon Phenomenon as an alternate heat sink of Shutdown Cooling System for the CANDU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jonghyun [GNEST, Seoul (Korea, Republic of); Lee, Kwangho; Oh, Haechol; Jun, Hwangyong [KEPRI, Taejon (Korea, Republic of)

    2006-07-01

    During the outage(overhaul) of the CANDU plant, there is a period when the coolant is partially drained to the reactor header level and the coolant is cooled and depressurized by Shutdown Cooling System(SDCS) other than PHTS pump. In the postulated accident of the loss of SDCS-the PHTS pump failure, the primary coolant system should be cooled by the alternate heat sink using the thermosyphon pheonomenon(TS) through the steam generator(SG) This study was aimed at verification and analyzing the core cooling ability of the TS. And the sensitivity analysis was done for the number of SGs used in the TS. As an analysis tool, RELAP5/CANDU was used.

  15. Design of a two-phase loop thermosyphon for telecommunications system(II): analysis and simulation

    International Nuclear Information System (INIS)

    Kim, Won Tae; Song, Kyu Sub; Lee, Young

    1998-01-01

    A computer simulation is performed for a two-phase loop thermosyphon for the B-ISDN telecommunications. The aim of this code development is to provide capabilities to predict the affects of many variables on the performance of the proposed TLT system using different empirical correlations obtained from the literature for the evaporation and condensation, and the shape factors available. In this present study, the simulation code is based on the sectorial thermal resistance network built on the flow regimes of the two-phase flows involved. The nodal resistances are solved by the typical Gauss-Seidal iteration method. The code can predict whether the proposed design is possible based on the flooding limit calculation of the system and its results are compared with the experimental results

  16. Design of a two-phase loop thermosyphon for telecommunications system(II): analysis and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Tae [Kongju National Univ., Kongju (Korea, Republic of); Song, Kyu Sub [Electronics and Telecommunications Research Institute, Taejon (Korea, Republic of); Lee, Young [Univ. of Ottawa, Ontario (Canada)

    1998-10-01

    A computer simulation is performed for a two-phase loop thermosyphon for the B-ISDN telecommunications. The aim of this code development is to provide capabilities to predict the affects of many variables on the performance of the proposed TLT system using different empirical correlations obtained from the literature for the evaporation and condensation, and the shape factors available. In this present study, the simulation code is based on the sectorial thermal resistance network built on the flow regimes of the two-phase flows involved. The nodal resistances are solved by the typical Gauss-Seidal iteration method. The code can predict whether the proposed design is possible based on the flooding limit calculation of the system and its results are compared with the experimental results.

  17. Experimental investigation of a two-phase closed thermosyphon assembly for passive containment cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Kyung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Sang Nyung [Kyunghee Univ., Gyeonggi-do (Korea, Republic of)

    2017-06-15

    After the Fukushima accident, increasing interest has been raised in passive safety systems that maintain the integrity of the containment building. To improve the reliability and safety of nuclear power plants, long-term passive cooling concepts have been developed for advanced reactors. In a previous study, the proposed design was based on an ordinary cylindrical Two-Phase Closed Thermosyphon (TPCT). The exact assembly size and number of TPCTs should be elaborated upon through accurate calculations based on experiments. While the ultimate goal is to propose an effective MPHP design for the PCCS and experimentally verify its performance, a TPCT assembly that was manufactured based on the conceptual design in this paper was tested.

  18. Performance evaluation of photovoltaic-thermosyphon system for subtropical climate application

    International Nuclear Information System (INIS)

    Chow, T.T.; He, W.; Chan, A.L.S.; Ji, J.

    2007-01-01

    The rapid development and sales volume of photovoltaic (PV) modules has created a promising business environment in the foreseeable future. However, the current electricity cost from PV is still several times higher than from the conventional power generation. One way to shorten the payback period is to bring in the hybrid photovoltaic-thermal (PVT) technology, which multiplies the energy outputs from the same collector surface area. In this paper, the performance evaluation of a new water-type PVT collector system is presented. The thermal collection making use of the thermosyphon principle eliminates the expense of pumping power. Experimental rigs were successfully built. A dynamic simulation model of the PVT collector system was developed and validated by the experimental measurements, together with two other similar models developed for PV module and solar hot-water collector. These were then used to predict the energy outputs and the payback periods for their applications in the subtropical climate, with Hong Kong as an example. The numerical results show that a payback period of 12 year for the PVT collector system is comparable to the side-by-side system, and is much shorter than the plain PV application. This is a great encouragement in marketing the PVT technology. (author)

  19. Performance evaluation of photovoltaic-thermosyphon system for subtropical climate application

    Energy Technology Data Exchange (ETDEWEB)

    Chow, T.T.; He, W.; Chan, A.L.S. [Division of Building Science and Technology, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR (China); Ji, J. [Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Anhui (China)

    2007-01-15

    The rapid development and sales volume of photovoltaic (PV) modules has created a promising business environment in the foreseeable future. However, the current electricity cost from PV is still several times higher than from the conventional power generation. One way to shorten the payback period is to bring in the hybrid photovoltaic-thermal (PVT) technology, which multiplies the energy outputs from the same collector surface area. In this paper, the performance evaluation of a new water-type PVT collector system is presented. The thermal collection making use of the thermosyphon principle eliminates the expense of pumping power. Experimental rigs were successfully built. A dynamic simulation model of the PVT collector system was developed and validated by the experimental measurements, together with two other similar models developed for PV module and solar hot-water collector. These were then used to predict the energy outputs and the payback periods for their applications in the subtropical climate, with Hong Kong as an example. The numerical results show that a payback period of 12 year for the PVT collector system is comparable to the side-by-side system, and is much shorter than the plain PV application. This is a great encouragement in marketing the PVT technology. (author)

  20. A 100-W grade closed-cycle thermosyphon cooling system used in HTS rotating machines

    Science.gov (United States)

    Felder, Brice; Miki, Motohiro; Tsuzuki, Keita; Shinohara, Nobuyuki; Hayakawa, Hironao; Izumi, Mitsuru

    2012-06-01

    The cooling systems used for rotating High-Temperature Superconducting (HTS) machines need a cooling power high enough to ensure a low temperature during various utilization states. Radiation, torque tube or current leads represent hundreds of watts of invasive heat. The architecture also has to allow the rotation of the refrigerant. In this paper, a free-convection thermosyphon using two Gifford-McMahon (GM) cryocoolers is presented. The cryogen is mainly neon but helium can be added for an increase of the heat transfer coefficient. The design of the heat exchangers was first optimized with FEM thermal analysis. After manufacture, they were assembled for preliminary experiments and the necessity of annealing was studied for the copper parts. A single evaporator was installed to evaluate the thermal properties of such a heat syphon. The maximum bearable static heat load was also investigated, but was not reached even at 150 W of load. Finally, this cooling system was tested in the cooling down of a 100-kW range HTS rotating machine containing 12 Bi-2223 double-pancake coils (DPC).

  1. Majorana Thermosyphon Prototype Experimental Results

    International Nuclear Information System (INIS)

    Fast, James E.; Reid, Douglas J.; Aguayo Navarrete, Estanislao

    2010-01-01

    The Majorana demonstrator will operate at liquid Nitrogen temperatures to ensure optimal spectrometric performance of its High Purity Germanium (HPGe) detector modules. In order to transfer the heat load of the detector module, the Majorana demonstrator requires a cooling system that will maintain a stable liquid nitrogen temperature. This cooling system is required to transport the heat from the detector chamber outside the shield. One approach is to use the two phase liquid-gas equilibrium to ensure constant temperature. This cooling technique is used in a thermosyphon. The thermosyphon can be designed so the vaporization/condensing process transfers heat through the shield while maintaining a stable operating temperature. A prototype of such system has been built at PNNL. This document presents the experimental results of the prototype and evaluates the heat transfer performance of the system. The cool down time, temperature gradient in the thermosyphon, and heat transfer analysis are studied in this document with different heat load applied to the prototype.

  2. Titanium-Water Thermosyphon Gamma Radiation Exposure and Results

    Science.gov (United States)

    Sanzi, James, L.A; Jaworske, Donald, A.; Goodenow, Debra, A.

    2012-01-01

    Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some gamma irradiation. Noncondensable gas formation from radiation-induced breakdown of water over time may render portions of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature under accelerated gamma irradiation, with exposures on the same order of magnitude as that expected in 8 years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon: evaporator, condenser, and condenser end cap. Some noncondensable gas was evident; however, thermosyphon performance was not affected because the noncondensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of noncondensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the noncondensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of one thermosyphon in a vacuum chamber and at temperature revealed that the noncondensable gas diffused out of the thermosyphon over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

  3. Titanium-Water Thermosyphon Gamma Radiation Effects and Results

    Science.gov (United States)

    Sanzi, James L.; Jaworske, Donald A.; Goodenow, Debra A.

    2012-01-01

    Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some exposure to gamma irradiation. Non-condensable gas formation from radiation may breakdown water over time and render a portion of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature with accelerated gamma irradiation exposures on the same order of magnitude that is expected in eight years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon; evaporator, condenser, and condenser end cap. Some non-condensable gas was evident, however thermosyphon performance was not affected because the non-condensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of non-condensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the non-condensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of selected thermosyphons at temperature and in a vacuum chamber revealed that the non-condensable gas likely diffused out of the thermosyphons over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

  4. Numerical investigation on effect of riser diameter and inclination on system parameters in a two-phase closed loop thermosyphon solar water heater

    International Nuclear Information System (INIS)

    Aung, Nay Zar; Li, Songjing

    2013-01-01

    Highlights: • Optimum inclination for maximum heat flux changes with latitude of location. • Optimum inclination for maximum heat flux also changes local solar time. • Maximum flow rate increases with increasing of riser tube size. • Maximum mass flow rate is obtained at different inclinations for different risers. • Length of two-phase region depends on inclination angles but not riser tube size. - Abstract: In this work, the effect of riser diameter and its inclination angle on system parameters in a two-phase closed loop thermosyphon solar water heater has been numerically investigated. Here, receivable heat flux by the collector, circulating mass flow rate, driving pressure, total pressure drop, heat transfer coefficient in risers and collector efficiency are defined as system parameters. For this aim, a model of two-phase thermosyphon solar water heater that is acceptable for various inclinations is presented and variations of riser diameter and inclination are considered. The riser tube size is varied from 1.25 cm to 2.5 cm with inclination range 2–75°. The system absolute pressure is set as 3567 Pa and water is chosen as working fluid. The results show that higher inclination angle is required for higher latitude location to obtain maximum solar heat flux. At local solar noon of 21.996 north latitude, the optimum inclination angle increases in the range of 24–44° with increasing of riser diameter giving maximum circulating mass flow rate from 0.02288 kg/s to 0.03876 kg/s. The longer two-phase heat transfer characteristics can be obtained at smaller inclination angles and mass flow rate for all riser tube sizes. Therefore, it is observed that the optimum inclination angles and diameters for solar heat flux, circulating mass flow rate and heat transfer coefficient in two-phase thermosyphon systemdo not coincide. From this work, better understanding and useful information are provided for constructing two-phase thermosyphon solar heaters

  5. Thermosyphon Cooler Hybrid System for Water Savings in an Energy-Efficient HPC Data Center: Modeling and Installation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Thomas; Liu, Zan; Sickinger, David; Regimbal, Kevin; Martinez, David

    2017-02-01

    The Thermosyphon Cooler Hybrid System (TCHS) integrates the control of a dry heat rejection device, the thermosyphon cooler (TSC), with an open cooling tower. A combination of equipment and controls, this new heat rejection system embraces the 'smart use of water,' using evaporative cooling when it is most advantageous and then saving water and modulating toward increased dry sensible cooling as system operations and ambient weather conditions permit. Innovative fan control strategies ensure the most economical balance between water savings and parasitic fan energy. The unique low-pressure-drop design of the TSC allows water to be cooled directly by the TSC evaporator without risk of bursting tubes in subfreezing ambient conditions. Johnson Controls partnered with the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories to deploy the TSC as a test bed at NREL's high-performance computing (HPC) data center in the first half of 2016. Located in NREL's Energy Systems Integration Facility (ESIF), this HPC data center has achieved an annualized average power usage effectiveness rating of 1.06 or better since 2012. Warm-water liquid cooling is used to capture heat generated by computer systems direct to water; that waste heat is either reused as the primary heat source in the ESIF building or rejected using evaporative cooling. This data center is the single largest source of water and power demand on the NREL campus, using about 7,600 m3 (2.0 million gal) of water during the past year with an hourly average IT load of nearly 1 MW (3.4 million Btu/h) -- so dramatically reducing water use while continuing efficient data center operations is of significant interest. Because Sandia's climate is similar to NREL's, this new heat rejection system being deployed at NREL has gained interest at Sandia. Sandia's data centers utilize an hourly average of 8.5 MW (29 million Btu/h) and are also one of the largest consumers of

  6. Thermosyphoning in the CANDU reactor

    International Nuclear Information System (INIS)

    Spinks, N.J.; Wright, A.C.D.; Caplan, M.Z.; Prawirosoehardjo, S.; Gulshani, P.

    1984-01-01

    Thermosyphoning is defined as the natural convective flow of primary coolant over the boilers. It is the predicted mode of heat transport from core to boilers in many postulated scenarios for CANDU reactor safety analysis. The scenarios encompass a wide range of boundary conditions in reactor power, secondary temperature and primary coolant inventory. Loss of pumping of the primary coolant is a common feature. Thermosyphoning is single or two-phase depending on the boundary conditions. The paper describes the important thermohydraulic characteristics of thermosyphoning in CANDU reactors with emphasis on two-phase thermosyphoning. It utilizes predictions of a transient thermohydraulics computer code and describes experiments done for the purpose of verifying these predictions. Predictions are compared with single-phase thermosyphoning tests done during commissioning of the Gentilly-2 and Point Lepreau CANDU 600 reactors. (orig.)

  7. Thermal performance of plate-type loop thermosyphon at sub-atmospheric pressures

    International Nuclear Information System (INIS)

    Tsoi, Vadim; Chang, Shyy Woei; Chiang Kuei Feng; Huang, Chuan Chin

    2011-01-01

    This experimental study examines the thermal performance of a newly devised plate-type two-phase loop thermosyphon with cooling applications to electronic boards of telecommunication systems. The evaporation section is configured as the inter-connected multi channels to emulate the bridging boiling mechanism in pulsating thermosyphon. Two thermosyphon plates using water as the coolant with filling ratios (FR) of 0.22 and 0.32 are tested at sub-atmospheric pressures. The vapor-liquid flow images as well as the thermal resistances and effective spreading thermal conductivities are individually measured for each thermosyphon test plate at various heating powers. The high-speed digital images of the vapor-liquid flow structures reveal the characteristic boiling phenomena and the vapor-liquid circulation in the vertical thermosyphon plate, which assist to explore the thermal physics for this type of loop thermosyphon. The bubble agglomeration and pumping action in the inter-connected boiling channels take place at metastable non-equilibrium conditions, leading to the intermittent slug flows with a pulsation character. Such hybrid loop-pulsating thermosyphon permits the vapor-liquid circulation in the horizontal plate. Thermal resistances and spreading thermal conductivities detected from the present thermosyphon plates; the vapor chamber flat plate heat pipe and the copper plate at free and forced convective cooling conditions with both vertical and horizontal orientations are cross-examined. In most telecommunication systems and units, the electrical boards are vertical so that the thermal performance data on the vertical thermosyphon are most relevant to this particular application. - Highlights: → We examine thermal performances of plate-type loop thermosyphon. → Thermal resistances and spreading conductivities are examined. → Bubble agglomeration in inter-connected boiling channels generates intermittent slug flows with pulsations. → Boiling instability

  8. Thermosyphon Flooding Limits in Reduced Gravity Environments

    Science.gov (United States)

    Gibson, Marc A.; Jaworske, Donald A.; Sanzi, James L.; Ljubanovic, Damir

    2012-01-01

    Fission Power Systems have long been recognized as potential multi-kilowatt power solutions for lunar, Martian, and extended planetary surface missions. Current heat rejection technology associated with fission surface power systems has focused on titanium water thermosyphons embedded in carbon composite radiator panels. The thermosyphons, or wickless heat pipes, are used as a redundant and efficient way to spread the waste heat from the power conversion unit(s) over the radiator surface area where it can be rejected to space. It is well known that thermosyphon performance is reliant on gravitational forces to keep the evaporator wetted with the working fluid. One of the performance limits that can be encountered, if not understood, is the phenomenon of condenser flooding, otherwise known as evaporator dry out. This occurs when the gravity forces acting on the condensed fluid cannot overcome the shear forces created by the vapor escaping the evaporator throat. When this occurs, the heat transfer process is stalled and may not re-stabilize to effective levels without corrective control actions. The flooding limit in earth's gravity environment is well understood as experimentation is readily accessible, but when the environment and gravity change relative to other planetary bodies, experimentation becomes difficult. An innovative experiment was designed and flown on a parabolic flight campaign to achieve the Reduced Gravity Environments (RGE) needed to obtain empirical data for analysis. The test data is compared to current correlation models for validation and accuracy.

  9. In-Situ Measurements of the Performance of Thermosyphon Solar Water Heating Systems in Libya

    International Nuclear Information System (INIS)

    Abdunnabi, M. I. R.; Loveday, D. L.

    2014-01-01

    This paper reports on a project carried out by the Centre for Solar Energy Research and Studies (CSERS) to familiarize Libyan people with solar water heating technologies. Around 100 solar water heaters have been installed in the domestic sector and selected systems were equipped with monitoring instruments required to evaluate thermal performance. The paper presents the results of data collected over a one year period from a system installed in a family residence situated in a village located 90 km south of Tripoli (Libyan capital). The results showed that the system solar fraction was 55.8% of the average amount of daily hot water withdrawn (144 liters) at an average withdrawal temperature of 46.6 °. The total energy withdrawn during the whole year was 1557 kWl1. It is concluded that such a system is not adequate in terms of cost effectiveness for the current installed situation. It is recommended that the annual solar fraction for any solar water heating system should be over 70° in order to achieve cost—effectiveness and to help wide spread take—up of this technology.(author)

  10. Performance of Thermosyphon Solar Water Heaters in Series

    Directory of Open Access Journals (Sweden)

    Tsong-Sheng Lee

    2012-08-01

    Full Text Available More than a single thermosyphon solar water heater may be employed in applications when considerable hot water consumption is required. In this experimental investigation, eight typical Taiwanese solar water heaters were connected in series. Degree of temperature stratification and thermosyphon flow rate in a horizontal tank were evaluated. The system was tested under no-load, intermittent and continuous load conditions. Results showed that there was stratification in tanks under the no-load condition. Temperature stratification also redeveloped after the draw-off. Analysis of thermal performance of the system was conducted for each condition.

  11. Experimental studies on heat transfer and thermal performance characteristics of thermosyphon solar water heating system with helical and Left-Right twisted tapes

    International Nuclear Information System (INIS)

    Jaisankar, S.; Radhakrishnan, T.K.; Sheeba, K.N.

    2011-01-01

    Research highlights: → Conventional solar heaters are inefficient due to poor convective heat transfer. → Twisted tapes improve the heat transfer rate in solar water heater system. → Increase in outlet water temperature by 15 o C through the use of twisted tapes. →Thermal performance of twisted tape collector is 19% more than plain tube system. → Reduces collector area (0.6 m 2 ) whereas area for conventional collector is 1 m 2 . -- Abstract: Experimental investigation of heat transfer, friction factor and thermal performance of thermosyphon solar water heater system fitted with helical and Left-Right twist of twist ratio 3 has been performed and presented. The helical twisted tape induces swirl flow inside the riser tubes unidirectional over the length. But, in Left-Right system the swirl flow is bidirectional which increases the heat transfer and pressure drop when compared to the helical system. The experimental heat transfer and friction factors characteristics are validated with theoretical equations and the deviation falls with in the acceptable limits. The results show that heat transfer enhancement in twisted tape collector is higher than the plain tube collector. Compared to helical and Left-Right twisted tape system of same twist ratio 3, maximum thermal performance is obtained for Left-Right twisted tape collector with increase in solar intensity.

  12. Investigation of the thermal performance of a vertical two-phase closed thermosyphon as a passive cooling system for a nuclear reactor spent fuel storage pool

    Energy Technology Data Exchange (ETDEWEB)

    Kusuma, Mukhsinun Hadi; Putra, Nandy; Imawan, Ficky Augusta [Heat Transfer Laboratory, Department of Mechanical Engineering Universitas Indonesia, Kampus (Indonesia); Antariksawan, Anhar Riza [Centre for Nuclear Reactor Safety and Technology, National Nuclear Energy Agency of Indonesia (BATAN), Kawasan Puspiptek Serpong (Indonesia)

    2017-04-15

    The decay heat that is produced by nuclear reactor spent fuel must be cooled in a spent fuel storage pool. A wickless heat pipe or a vertical two-phase closed thermosyphon (TPCT) is used to remove this decay heat. The objective of this research is to investigate the thermal performance of a prototype model for a large-scale vertical TPCT as a passive cooling system for a nuclear research reactor spent fuel storage pool. An experimental investigation and numerical simulation using RELAP5/MOD 3.2 were used to investigate the TPCT thermal performance. The effects of the initial pressure, filling ratio, and heat load were analyzed. Demineralized water was used as the TPCT working fluid. The cooled water was circulated in the water jacket as a cooling system. The experimental results show that the best thermal performance was obtained at a thermal resistance of 0.22°C/W, the lowest initial pressure, a filling ratio of 60%, and a high evaporator heat load. The simulation model that was experimentally validated showed a pattern and trend line similar to those of the experiment and can be used to predict the heat transfer phenomena of TPCT with varying inputs.

  13. Thermal performance of an open thermosyphon using nanofluid for evacuated tubular high temperature air solar collector

    International Nuclear Information System (INIS)

    Liu, Zhen-Hua; Hu, Ren-Lin; Lu, Lin; Zhao, Feng; Xiao, Hong-shen

    2013-01-01

    Highlights: • A novel solar air collector with simplified CPC and open thermosyphon is designed and tested. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • Nanofluid effectively improves thermal performance of the above solar air collector. • Solar air collector with open thermosyphon is better than that with concentric tube. - Abstract: A novel evacuated tubular solar air collector integrated with simplified CPC (compound parabolic concentrator) and special open thermosyphon using water based CuO nanofluid as the working fluid is designed to provide air with high and moderate temperature. The experimental system has two linked panels and each panel includes an evacuated tube, a simplified CPC and an open thermosyphon. Outdoor experimental study has been carried out to investigate the actual solar collecting performance of the designed system. Experimental results show that air outlet temperature and system collecting efficiency of the solar air collector using nanofluid as the open thermosyphon’s working fluid are both higher than that using water. Its maximum air outlet temperature exceeds 170 °C at the air volume rate of 7.6 m 3 /h in winter, even though the experimental system consists of only two collecting panels. The solar collecting performance of the solar collector integrated with open thermosyphon is also compared with that integrated with common concentric tube. Experimental results show that the solar collector integrated with open thermosyphon has a much better collecting performance

  14. Thermosyphon Flooding in Reduced Gravity Environments

    Science.gov (United States)

    Gibson, Marc Andrew

    2013-01-01

    An innovative experiment to study the thermosyphon flooding limits was designed and flown on aparabolic flight campaign to achieve the Reduced Gravity Environments (RGE) needed to obtainempirical data for analysis. Current correlation models of Faghri and Tien and Chung do not agreewith the data. A new model is presented that predicts the flooding limits for thermosyphons inearths gravity and lunar gravity with a 95 confidence level of +- 5W.

  15. Experimental investigations of heat transfer from an internally finned two phase closed thermosyphon

    International Nuclear Information System (INIS)

    Naresh, Y.; Balaji, C.

    2017-01-01

    Highlights: • Experimental investigations on an internally finned vertical thermosyphon. • Two fluids – water and acetone considered. • Optimum fill ratio determined to be 50%. • Addition of internal fins at the condenser leads to improved thermal performance. - Abstract: This paper reports the results of an experimental investigation of heat transfer from an internally finned thermosyphon charged with either water or acetone. Six constant area fins with a rectangular cross section are placed internally along the length at the condenser section. The ratio of initial liquid pool volume to the evaporator volume, known as the filling ratio in a thermosyphon system, has been varied in this study. Experiments are carried out for filling ratios of 20, 50, and 80% for two working fluids (i) water and (ii) acetone. Results show that a fill ratio of 50% gives better heat transfer performance. Providing internal fins at the condenser produces additional condensation which improves the thermal performance of the thermosyphon by 17% in terms of the temperature reduction at the source and sink and 35.48% in terms of reduction in thermal resistance at lower heat inputs. The thermosyphon is tested between power levels of 50 and 275 W.

  16. Experimental investigation of heat transfer and friction factor characteristics of thermosyphon solar water heater system fitted with spacer at the trailing edge of Left-Right twisted tapes

    International Nuclear Information System (INIS)

    Jaisankar, S.; Radhakrishnan, T.K.; Sheeba, K.N.; Suresh, S.

    2009-01-01

    Experimental investigation of heat transfer and friction factor characteristics of thermosyphon solar water heater with full length Left-Right twist, twist fitted with rod and spacer at the trailing edge for lengths of 100, 200 and 300 mm for twist ratio 3 and 5 has been studied. The experimental data for plain tube collector has been compared with fundamental equation within a discrepancy of ±7.41% and ±14.97% for Nusselt number and friction factor, respectively. Result shows that the Nusselt number decreases by 11% and 19% for twist fitted with rod and twist with spacer, respectively, when compared with full length twist. Friction factor also decreases by 18% and 29% for twist fitted with rod and spacer, respectively, as compared with full length twist. The heat enhancement in twist fitted with rod at the trailing edge is maximum when compared with twist fitted with spacer because the swirl flow is maintained throughout the length of rod.

  17. Evaluation of the thermal performance of a solar water heating thermosyphon versus a two-phase closed thermosyphon using different working fluids

    Energy Technology Data Exchange (ETDEWEB)

    Ordaz-Flores, A. [Posgrado en Ingenieria (Energia), Univ. Nacional Autonoma de Mexico, Temixco, Morelos (Mexico); Garcia-Valladares, O.; Gomez, V.H. [Centro de Investigacion en Energia, Univ. Nacional Autonoma de Mexico, Temixco, Morelos (Mexico)

    2008-07-01

    A water heating closed two-phase thermosyphon solar system was designed and built. The system consists of a flat plate solar collector coupled to a thermotank by a continuous copper tubing in which the working fluid circulates. The working fluid evaporates in the collector and condensates in the thermotank transferring its latent heat to the water through a coil heat exchanger. The tested fluids are acetone and R134a. The thermal performance of the proposed systems is compared with a conventional solar water thermosyphon under the same operating conditions. Advantages of a two-phase system include the elimination of freezing, fouling, scaling and corrosion. Geometry and construction materials are the same except for the closed circuit presented in the two-phase system. Data were collected from temperature and pressure sensors throughout the two systems. Early results suggest that R134a may provide a better performance than acetone for this kind of systems. (orig.)

  18. Analysis of the thermal performance of a low-cost solar heating system; Analise do desempenho termico de um sistema de aquecimento solar de baixo custo

    Energy Technology Data Exchange (ETDEWEB)

    Lopo, Alexandre Boleira

    2010-02-15

    A solar collector to be used in a system for heating water for bathing, whose main characteristics are low cost and easy manufacturing and assembly is presented. The system operates under natural convection or thermosyphon. The absorbing surface of the collector is formed by twelve PVC pipes of 25 mm outside diameter connected in parallel via connections in T of the same material. The tubes were covered with absorbing fins made by recycled aluminum cans. We studied eight settings between absorber plate, thermal insulating EPS boards and thermal reservoirs 150 and 200 liters. It was determined the most efficient configuration for the correct purpose. We evaluated thermal parameters that proved the viability of the heating system studied (author)

  19. Numerical and experimental investigation of thermosyphon solar water heater

    International Nuclear Information System (INIS)

    Zelzouli, Khaled; Guizani, Amenallah; Kerkeni, Chakib

    2014-01-01

    Highlights: • We studied a thermosyphon solar water heater composed of high-performance components. • A differential equations solution technique is investigated. • The influences of the collector and storage losses on the system performance were examined. • The storage losses have more influence on the long-term performance. - Abstract: A glassed flat plate collector with selective black chrome coated absorber and a low wall conductance horizontal storage are combined in order to set up a high performance thermosyphon system. Each component is tested separately before testing the complete system in spring days. During the test period, effect of different inlet water temperatures on the collector performance is studied and results have shown that the collector can reach a high efficiency and high outlet water temperature even for elevated inlet water temperatures. Subsequently, long term system performance is estimated by using a developed numerical model. The proposed model, accurate and gave a good agreement with experimental results, allowed to describe the heat transfer in the storage. It has shown also that the long-term performances are strongly influenced by losses from the storage than losses from the collector

  20. Effect of non-condensable gas on startup of a loop thermosyphon

    International Nuclear Information System (INIS)

    He, Jiang; Lin, Guiping; Bai, Lizhan; Miao, Jianyin; Zhang, Hongxing; Wang, Lu

    2013-01-01

    Non-condensable gas (NCG) generated inside two-phase heat transfer devices can adversely affect the thermal performance and limit the lifetime of such devices. In this work, experimental investigation of the effect of NCG on the startup of an ammonia-stainless steel loop thermosyphon was conducted. In the experiment, nitrogen was injected into the loop thermosyphon as NCG. The effect of NCG inventory on the startup behavior was investigated by adjusting the injected amount of nitrogen. The experimental results reveal that NCG prolongs the startup time and increases the startup liquid superheat and temperature overshoot; the more NCG exists in the loop thermosyphon, the higher the liquid superheat and temperature overshoot. When NCG is present in the system, boiling usually occurs in the evaporator before startup, but it does not mean the system will start up instantly, which differs from the conditions without NCG. Under all the conditions, increasing the heat load can effectively shorten the startup time but leads to a large temperature overshoot; forced convection cooling of the condenser has almost no effect on shortening the startup time especially for large NCG inventory situations, but it can effectively limit the temperature overshoot. For large NCG inventory situations, the loop thermosyphon can start up at a small heat load (5 W) or even without a heat load when the condenser is cooled by forced convection of ethanol. No failed start-ups occurred during any of the tests. (authors)

  1. MMOSS-I: a CANDU multiple-channel thermosyphoning flow stability model

    Energy Technology Data Exchange (ETDEWEB)

    Gulshani, P [Atomic Energy of Canada Ltd., Mississauga, ON (Canada); Huynh, H [Hydro-Quebec, Montreal, PQ (Canada)

    1996-12-31

    This paper presents a multiple-channel flow stability model, dubbed MMOSS, developed to predict the conditions for the onset of flow oscillations in a CANDU-type multiple-channel heat transport system under thermosyphoning conditions. The model generalizes that developed previously to account for the effects of any channel flow reversal. Two-phase thermosyphoning conditions are predicted by thermalhydraulic codes for some postulated accident scenarios in CANDU. Two-phase thermosyphoning experiments in the multiple-channel RD-14M facility have indicated that pass-to-pass out-of-phase oscillations in the loop conditions caused the flow in some of the heated channels to undergo sustained reversal in direction. This channel flow reversal had significant effects on the channel and loop conditions. It is, therefore, important to understand the nature of the oscillations and be able to predict the conditions for the onset of the oscillations or for stable flow in RD-14M and the reactor. For stable flow conditions, oscillation-induced channel flow reversal is not expected. MMOSS was developed for a figure-of-eight system with any number of channels. The system characteristic equation was derived from a linearization of the conservation equations. In this paper, the MMOSS characteristic equation is solved for a system of N identical channel assemblies. The resulting model is called MMOSS-I. This simplification provides valuable physical insight and reasonably accurate results. MMOSS-I and a previously-developed steady-state model THERMOSYPHON are used to predict thermosyphoning flow stability maps for RD-14M and the Gentilly 2 reactor. (author). 11 refs., 7 figs.

  2. Experimental investigation of using ambient energy to cool Internet Data Center with thermosyphon heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, F.; Tian, X.; Ma, G. [Beijing Univ. of Technology, Beijing (China). College of Environmental and Energy Engineering

    2010-07-01

    The energy consumption of the air-conditioning system at the Internet Data Center (IDC) in Beijing comprises 40 per cent of the building's total energy consumption. Of all the energy energy management strategies available at the IDC, the most unique one is the use of ambient energy to cool the IDC by the thermosyphon heat exchanger. Atmospheric energy can reduce the air conditioner's running time while maintaining the humidity and cleanliness of the IDC. In this study, an IDC test model was set up to analyze the heat dissipating characteristics and the energy consumption of the thermosyphon heat exchanger and the air conditioner in the IDC for winter conditions. The heat dissipating capacity of the building envelope was measured and calculated. The energy consumption of the air conditioner was compared under different indoor and outdoor temperatures. The study showed that the heat dissipating need of the IDC cannot be met just by the heat dissipation of the building envelope in winter conditions. The heat dissipating capacity of the IDC building envelope comprises 19.5 per cent of the total heat load. The average energy consumption of the air conditioner is 3.5 to 4 kWh per day. The temperature difference between indoor and outdoor temperature in the IDC with the thermosyphon heat exchanger was less than 20 degrees C, and the energy consumption of the thermosyphon heat exchanger comprised only 41 per cent of that of the air conditioner. 8 refs., 1 tab., 8 figs.

  3. Experimental investigations and modeling of a loop thermosyphon for cooling with zero electrical consumption

    International Nuclear Information System (INIS)

    Chehade, Ali; Louahlia-Gualous, Hasna; Le Masson, Stéphane; Lépinasse, Eric

    2015-01-01

    This paper presents an analytical model for a thermosyphon loop developed for cooling air inside a telecommunication cabinet. The proposed model is based on the combination of thermal and hydraulic management of two-phase flow in the loop. Experimental tests on a closed thermosyphon loop are conducted with different working fluids that could be used for electronic cooling. Correlations for condensation and evaporation heat transfer in the thermosyphon loop are proposed. They are used in the model to calculate condenser and evaporator thermal resistances in order to predict the cabinet operating temperature, the loop's mass flow rate and pressure drops. Furthermore, various figures of merit proposed in the previous works are evaluated in order to be used for selection of the best loop's working fluid. The comparative studies show that the present model well predicts the experimental data. The mean deviation between the predictions of the theoretical model with the measurements for operating temperature is about 6%. Besides, the model is used to define an optimal liquid and vapor lines diameters and the effect of the ambient temperature on the fluid's mass flow rate and pressure drop. - Highlights: • Modeling of thermosyphon loop for cooling telecommunication cabinet. • The cooling system operates with zero electrical consumption. • The new correlations are proposed for condensation and evaporation heat transfer. • FOM equation is defined for selecting the best working fluid. • The proposed model well predicts the experimental data and operating temperature

  4. Experimental analysis of natural convection within a thermosyphon

    International Nuclear Information System (INIS)

    Clarksean, R.

    1993-01-01

    The heat transfer characteristics of a thermosyphon designed to passively cool cylindrical heat sources are experimentally studied. The analysis is based on recognizing the physics of the flow within different regions of the thermosyphon to develop empirical heat transfer correlations. The basic system consists of three concentric cylinders, with an outer channel between the outer two cylinders, and an inner channel between the inner two cylinders. Tests were conducted. with two different process material container diameters, representing the inner cylinder, and several different power levels. The experimentally determined local and average Nu numbers for the inner channel are in good agreement with previous work for natural convection between vertical parallel plates, one uniformly heated and the other thermally insulated. The implication is that the heat transfer off of each surface is independent of the adjacent surface for sufficiently high Ra numbers. The heat transfer is independent because of limited interaction between the boundary layers at sufficiently high Ra numbers. As a result of the limited interaction, the maximum temperature within the system remained constant, or decreased slightly when the radii of the inner cylinders increased for the same amount of heat removal

  5. Visualisation of flow patterns in straight and C-shape thermosyphons

    Science.gov (United States)

    Ong, K. S.; Tshai, K. H.; Firwana, A.

    2017-04-01

    A heat pipe is a passive heat transfer device capable of transferring a large quantity of heat effectively and efficiently over a long distance and with a small temperature difference between the heat source and heat sink. A heat pipe consists of a metal pipe initially vacuumed and then filled with a small quantity of fluid inside. The pipe is separated into a heating (evaporator) section and a cooling (condenser) section by an adiabatic section. In a run-around-coil heating, ventilation and air conditioning system, a wrap-around heat pipe heat exchanger could be employed to increase dehumidification and to reduce cooling costs. The thermal performance of a thermosyphon is dependent upon type of fill liquid, fill ratio, power input, pipe inclination and pipe dimensions. The boiling and condensation processes that occur inside a thermosyphon are quite complex. During operation, dry-out, burn-out or boiling limit, entrainment or flooding limit and geysering occur. These phenomena would lead to non-uniform axial wall temperature distribution in the pipe, or worse still, ineffective operation. In order to have a better understanding of the internal heat transfer phenomena, a visual study using transparent glass tubes and high speed camera recording of the internal flow patterns would be most helpful. This paper reports on an experimental investigation conducted to visualise the flow patterns in straight and C-shape thermosyphons. The pictures recorded enabled the internal flow boiling and condensation pattern occurring inside a straight and a C-shape thermosyphon to be observed. The thermosyphons were fabricated from 10 mm O/D × 8 mm I/D × 300 mm long glass tubes and filled with water with fill ratios from 0.5 - 1.5. The evaporator sections of the thermosyphons were immersed into a hot water tank that was electrically heated from cold at ambient temperature till boiling. Cooling of the condenser section was achieved using a fan. Preliminary results showed that dry

  6. Evaluation of the decay heat removal capability using the concept of a thermosyphon in the liquid metal reactor

    International Nuclear Information System (INIS)

    Kim, Y. S.; Sim, Y. S.; Kim, W. K.

    2000-01-01

    A study related to understand the characteristics of the heat pipe and thermosyphon was performed to evaluate their applicabilities to the current PSDRS (Passive Safety Decay heat Removal System) in the KALIMER (Korea Advanced LIquid MEtal Reactor) design. The possible heat transfer rate by the heat pipe and thermosyphon was reviewed to compare the required capability in the PSDRS. A quantitative comparison was done between the current PSDRS and the modified PSDRS with the thermosyphon. The result showed the dominant heat transfer rate in the air channel, e.g. radiation or convection, is different from each other. The total heat transfer rate is not sensitive to the operating temperature of the thermosyphon. The heat removal by the air in the modified case is relatively reduced and the resultant outlet temperature appears less than above 10 .deg. C. A reversal heat transfer between the air and the thermosyphon may exist near the exit of the active heat transfer region. The total heat transfer rate by the modified case showed about 20∼40% increase relative to the reference one

  7. Predicting heat transfer in long, R-134a filled thermosyphons

    NARCIS (Netherlands)

    Grooten, M.H.M.; Geld, van der C.W.M.

    2008-01-01

    When traditional air-to-air cooling is too voluminous, heat exchangers with long thermosyphons offer a good alternative. Experiments with a single thermosyphon with a large length-to-diameter ratio (188) and filled with R-134a are presented and analyzed. Saturation temperatures, filling ratios, and

  8. EXPERIMENTAL INVESTIGATION ON THE PERFORMANCE OF THERMOSYPHON SOLAR WATER HEATER IN THE SOUTH CASPIAN SEA

    Directory of Open Access Journals (Sweden)

    Abdollah Riahi

    2011-01-01

    Full Text Available In the present study, a natural circulation closed thermosyphon flat plate solar water heater has been tested at the Faculty of Engineering of University of Mazandaran located in Babol city (36N, 52E. Data were collected for several sunny and cloudy days. Dynamic response of the system to variations in solar insolation was studied and analyzed. It was found that such systems can provide ample energy to satisfy the demand for hot water, contrary to misperception among locals

  9. Thermal Interface Evaluation of Heat Transfer from a Pumped Loop to Titanium-Water Thermosyphons

    Science.gov (United States)

    Jaworske, Donald A.; Sanzi, James L.; Gibson, Marc A.; Sechkar, Edward A.

    2009-01-01

    Titanium-water thermosyphons are being considered for use in the heat rejection system for lunar outpost fission surface power. Key to their use is heat transfer between a closed loop heat source and the heat pipe evaporators. This work describes laboratory testing of several interfaces that were evaluated for their thermal performance characteristics, in the temperature range of 350 to 400 K, utilizing a water closed loop heat source and multiple thermosyphon evaporator geometries. A gas gap calorimeter was used to measure heat flow at steady state. Thermocouples in the closed loop heat source and on the evaporator were used to measure thermal conductance. The interfaces were in two generic categories, those immersed in the water closed loop heat source and those clamped to the water closed loop heat source with differing thermal conductive agents. In general, immersed evaporators showed better overall performance than their clamped counterparts. Selected clamped evaporator geometries offered promise.

  10. Experimental and computational study on thermoelectric generators using thermosyphons with phase change as heat exchangers

    International Nuclear Information System (INIS)

    Araiz, M.; Martínez, A.; Astrain, D.; Aranguren, P.

    2017-01-01

    Highlights: • Thermosyphon with phase change heat exchanger computational model. • Construction and experimentation of a prototype. • ±9% of maximum deviation from experimental values of the main outputs. • Influence of the auxiliary equipment on the net power generation. - Abstract: An important issue in thermoelectric generators is the thermal design of the heat exchangers since it can improve their performance by increasing the heat absorbed or dissipated by the thermoelectric modules. Due to its several advantages, compared to conventional dissipation systems, a thermosyphon heat exchanger with phase change is proposed to be placed on the cold side of thermoelectric generators. Some of these advantages are: high heat-transfer rates; absence of moving parts and lack of auxiliary consumption (because fans or pumps are not required); and the fact that these systems are wickless. A computational model is developed to design and predict the behaviour of this heat exchangers. Furthermore, a prototype has been built and tested in order to demonstrate its performance and validate the computational model. The model predicts the thermal resistance of the heat exchanger with a relative error in the interval [−8.09; 7.83] in the 95% of the cases. Finally, the use of thermosyphons with phase change in thermoelectric generators has been studied in a waste-heat recovery application, stating that including them on the cold side of the generators improves the net thermoelectric production by 36% compared to that obtained with finned dissipators under forced convection.

  11. Optimized design of an ex-vessel cooling thermosyphon for decay heat removal in SFR

    International Nuclear Information System (INIS)

    Choi, Jae Young; Jeong, Yong Hoon; Song, Sub Lee; Chang, Soon Heung

    2017-01-01

    Passive decay heat removal and sodium fire are two major key issues of nuclear safety in sodium-cooled fast reactor (SFR). Several decay heat removal systems (DHR) were suggested for SFR around the world so far. Those DHRS mainly classified into two concepts: Direct reactor cooling system and ex-vessel cooling system. Direct reactor cooling method represented by PDHRS from PGSFR has disadvantages on its additional in-vessel structure and potential sodium fire risk due to the sodium-filled heat exchanger exposed to air. Contrastively, ex-vessel cooling method represented by RVACS from PRISM has low decay heat removal performance, which cannot be applicable to large scale reactors, generally over 1000 MWth. No passive DHRSs which can solve both side of disadvantages has been suggested yet. The goal of this study was to propose ex-vessel cooling system using two-phase closed thermosyphon to compensate the disadvantages of the past DHRSs. Reference reactor was Innovative SFR (iSFR), a pool-type SFR designed by KAIST and featured by extended core lifetime and increased thermal efficiency. Proposed ex-vessel cooling system consisted of 4 trains of thermosyphons and designed to remove 1% of thermal power with 10% of margin. The scopes of this study were design of proposed passive DHRS, validation of system analysis and optimization of system design. Mercury was selected as working fluid to design ex-vessel thermosyphon in consideration of system geometry, operating temperature and required heat flux. SUS 316 with chrome coated liner was selected as case material to resist against high corrosivity of mercury. Thermosyphon evaporator was covered on the surface of reactor vessel as the geometry of hollow shell filled with mercury. Condenser was consisted of finned tube bundles and was located in isolated water pool, the ultimate heat sink. Operation limits and thermal resistance was estimated to guarantee whether the design was adequate. System analysis was conducted by in

  12. Thermosyphon evaporator for nuclear waste management application

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Rajani; Singh, A K; Rana, D S [Waste Management Projects Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Nuclear plant equipment are associated with radioactive material which needs to be safely contained under all conditions of operation. Because of large radioactivity associated with the operations of nuclear waste management plants, the equipment are not accessible to human intervention. Hence, the design of the equipment needs to incorporate features for high reliability and safety so as to avoid unnecessary outage. As far as possible the equipment must be maintenance free. Wherever maintenance is inevitable, it has to be designed to be carried out without exposure of personnel to radiation, preventing spread of radiation or contamination. This paper outlines the design features of a thermosyphon evaporator for nuclear application. (author). 2 figs., 1 tab.

  13. Modeling and experimental tests of a copper thermosyphon

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Dias dos Santos

    2017-02-01

    Full Text Available Electrical energy, solar energy, and/or direct combustion of a fuel are the most common thermal sources for home water heating. In recent years, the use of solar energy has become popular because it is a renewable and economic energy source. Among the solar collectors, those assisted by thermosyphons are more efficient; therefore, they can enhance the heat transfer to water. A thermosyphon is basically a sealed tube filled with a working fluid and, normally, it has three regions: the evaporator, the adiabatic section and the condenser. The great advantage of this device is that the thermal resistance to heat transfer between its regions is very small, and as a result, there is a small temperature difference. This article aims to model a thermosyphon by using correlations based on its operation limits. This modeling will be used as a design tool for compact solar collectors assisted by thermosyphons. Based on the results obtained with the mathematical modeling, one copper thermosyphon, with deionized water as the working fluid, was developed and experimentally tested. The tests were carried out for a heat load varying from 30 to 60W in a vertical position. The theoretical and experimental results were compared to verify the mathematical model.

  14. Advanced multi-evaporator loop thermosyphon

    International Nuclear Information System (INIS)

    Mameli, M.; Mangini, D.; Vanoli, G.F.T.; Araneo, L.; Filippeschi, S.; Marengo, M.

    2016-01-01

    A novel prototype of multi-evaporator closed loop thermosyphon is designed and tested at different heaters position, inclinations and heat input levels, in order to prove that a peculiar arrangement of multiple heaters may be used in order to enhance the flow motion and consequently the thermal performance. The device consists in an aluminum tube (Inner/Outer tube diameter 3.0 mm/5.0 mm), bent into a planar serpentine with five U-turns and partially filled with FC-72, 50% vol. The evaporator zone is equipped with five heated patches (one for each U-turn) in series with respect to the flow path. In the first arrangement, heaters are wrapped on each bend symmetrically, while in the second layout heaters are located on the branch just above the U-turn, non-symmetrical with respect to the gravity direction, in order to promote the fluid circulation in a preferential direction. The condenser zone is cooled by forced air and equipped with a 50 mm transparent section for the flow pattern visualization. The non-symmetrical heater arrangement effectively promotes a stable fluid circulation and a reliable operation for a wider range of heat input levels and orientations with respect to the symmetrical case. In vertical position, the heat flux dissipation exceeds the pool boiling heat transfer limit for FC-72 by 75% and the tube wall temperatures in the evaporator zone are kept lower than 80 °C. Furthermore, the heat flux capability is up to five times larger with respect to the other existing wickless heat pipe technologies demonstrating the attractiveness of the new concept for electronic cooling thermal management. - Highlights: • A novel passive heat transfer device named Multi-Evaporator Loop Thermosyphon is tested. • The loop is investigated at different heating patterns, inclinations and heat power levels. • The non-symmetrical heating configuration promotes the fluid circulation within the loop. • The performance in terms of maximum heat flux exceeds the

  15. Exergy Analysis of Serpentine Thermosyphon Solar Water Heater

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal Hasan

    2018-03-01

    Full Text Available The performance of a solar hot water system is assessed for heat pump and domestic heating applications. Thermodynamic analysis on a serpentine-type thermosyphon flat-plate solar heater is conducted using the Second Law of thermodynamics. Exergetic optimization is first performed to determine the parameters for the maximum exergy efficiency using MATLAB optimization toolbox. Geometric parameters (collector surface area, dimensions, and pipe diameter, optical parameters (transmittance absorptance product, ambient temperature, solar irradiation and operating parameters (mass flow rate, fluid temperature, and overall heat transfer (loss coefficient are accounted for in the optimization scheme. The exergy efficiency at optimum condition is found to be 3.72%. The results are validated using experimental data and found to be in good agreement. The analysis is further extended to the influence of various operating parameters on the exergetic efficiency. It is observed that optical and thermal exergy losses contribute almost 20%, whereas approximately 77% exergy destruction is contributed by the thermal energy conversion. Exergy destruction due to pressure drop is found negligible. The result of this analysis can be used for designing and optimization of domestic heat pump system and hot water application.

  16. A thermosyphon heat pipe cooler for high power LEDs cooling

    Science.gov (United States)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  17. Thermosyphon Flooding in Reduced Gravity Environments Test Results

    Science.gov (United States)

    Gibson, Marc A.; Jaworske, Donald A.; Sanzi, Jim; Ljubanovic, Damir

    2013-01-01

    The condenser flooding phenomenon associated with gravity aided two-phase thermosyphons was studied using parabolic flights to obtain the desired reduced gravity environment (RGE). The experiment was designed and built to test a total of twelve titanium water thermosyphons in multiple gravity environments with the goal of developing a model that would accurately explain the correlation between gravitational forces and the maximum axial heat transfer limit associated with condenser flooding. Results from laboratory testing and parabolic flights are included in this report as part I of a two part series. The data analysis and correlations are included in a follow on paper.

  18. Pressure control of a proton beam-irradiated water target through an internal flow channel-induced thermosyphon.

    Science.gov (United States)

    Hong, Bong Hwan; Jung, In Su

    2017-07-01

    A water target was designed to enhance cooling efficiency using a thermosyphon, which is a system that uses natural convection to induce heat exchange. Two water targets were fabricated: a square target without any flow channel and a target with a flow channel design to induce a thermosyphon mechanism. These two targets had the same internal volume of 8 ml. First, visualization experiments were performed to observe the internal flow by natural convection. Subsequently, an experiment was conducted to compare the cooling performance of both water targets by measuring the temperature and pressure. A 30-MeV proton beam with a beam current of 20 μA was used to irradiate both targets. Consequently, the target with an internal flow channel had a lower mean temperature and a 50% pressure drop compared to the target without a flow channel during proton beam irradiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Thermosyphoning analysis with the CATHENA model of the blanket and first wall cooling loop for the SEAFP reactor design

    International Nuclear Information System (INIS)

    Ross, W.E.

    1994-02-01

    This report documents the thermosyphoning analysis which was performed with the CATHENA network model of one of the blanket and first wall cooling loops of the SEAFP reactor design. This thermosyphoning analysis includes four simulations, each with a slightly different model feature or assumption. These simulations are performed to assess the primary heat transport system behaviour for a complete loss of electrical power event (total loss of flow) and to estimate the rate and extent of heat-up of the incore components. For each event, a description of some of the important aspects of the transient thermalhydraulic behaviour including coolant temperatures, circuit and sector flows, circuit pressure, pressurizer level and outflow, and first wall and blanket temperatures is provided. (author). 4 refs., 2 tabs., 32 figs

  20. Subatmospheric boiling study of the operation of a horizontal thermosyphon reboiler loop: Instability

    International Nuclear Information System (INIS)

    Agunlejika, Ezekiel O.; Langston, Paul A.; Azzopardi, Barry J.; Hewakandamby, Buddhika N.

    2016-01-01

    Graphical abstract: The highlight of the characteristics of the geysering instability from analysed WMS data. Pictorial view of geysering instability, heat flux 9 kW/m"2 (P_S = 1.14 bar(a)), Static head = 1.265 m, valve setting = 1.0, process side pressure = 0.5 bar(a). - Highlights: • Characteristics of geysering instability in a horizontal thermosyphon reboiler loop is highlighted using Wire Mesh Sensor. • Interconnection between geysering instability and accompanying churn flow is identified. • Effects of stability parameters and pressure drop feedbacks on the loop at low heat fluxes are described. - Abstract: Distillation and chemical processing under vacuum is of immense interest to petroleum and chemical industries due to lower energy costs and improved safety. To tap into these benefits, energy efficient reboilers with lower maintenance costs are required. Here, a horizontal thermosyphon reboiler is investigated at subatmospheric pressures and low heat fluxes. This paper presents detailed experimental data obtained using Wire Mesh Sensor in a gas-liquid flow with heat transfer as well as temperatures, pressures and recirculation rates around the loop. Flow regimes which have been previously identified in other systems were detected. The nature of the instability which underpins the mechanisms involved and conditions aiding instability are reported. Churn flow pattern is persistently detected during instability. The nature of the instability and existence of oscillatory churn flow are interconnected.

  1. Rural electrification based on photovoltaic systems: systemic evaluation and analysis; Eletrificacao rural com sistemas fotovoltaicos: avaliacao e analise sistemicas

    Energy Technology Data Exchange (ETDEWEB)

    Orellana Lafuente, Renan Jorge

    1995-07-01

    In spite of all advances made by modern technology, there are still regions which remoteness has made electrification of poor rural localities very difficult or impossible. The only practical solution for these localities is a local, decentralized form of electrical generation, such as solar energy. Based on its availability and potential, together with the scientific and technical advances made in photovoltaic conversion, solar energy is an alternative which is viable for many rural areas in developing countries. The technology has matured sufficiently, but in its application there is still a need for systematization for experiences, especially in the areas of planning and management. The present work deals with a project carried in the community of Chimboata, Chimboata department, Bolivia. The implementation aspects are analysed and the implementation methodology described. Finally, the forms of managing and funding this type of systems are analysed. (author)

  2. Numerical simulation and experimental verification of a flat two-phase thermosyphon

    International Nuclear Information System (INIS)

    Zhang Ming; Liu Zhongliang; Ma Guoyuan; Cheng Shuiyuan

    2009-01-01

    The flat two-phase thermosyphon is placed between the heat source and the heat sink, which can achieve the uniform heat flux distribution and improve the performance of heat sink. In this paper, a two-dimensional heat and mass transfer model for a disk-shaped flat two-phase thermosyphon is developed. By solving the equations of continuity, momentum and energy numerically, the vapor velocity and temperature distributions of the flat two-phase thermosyphon are obtained. An analysis is also carried out on the ability of flat two-phase thermosyphon to spread heat and remove hot spots. In order to observe boiling and condensation phenomena, a transparent flat two-phase thermosyphon is manufactured and studied experimentally. The experimental results are compared with numerical results, which verify the physical and mathematical model of the flat two-phase thermosyphon. In order to study the main factors affecting the axial thermal resistance of two-phase thermosyphon, the temperatures inside the flat two-phase thermosyphon are measured and analyzed

  3. Numerical analyses of the effect of a biphasic thermosyphon vapor channel sizes on the heat transfer intensity when heat removing from a power transformer of combined heat and power station

    Directory of Open Access Journals (Sweden)

    Nurpeiis Atlant

    2017-01-01

    Full Text Available Numerical analyses of the effect of a biphasic thermosyphon vapor channel sizes on the heat transfer intensity was conducted when heat removing from an oil tank of a power transformer of combined heat and power station (CHP. The power transformer cooling system by the closed biphasic thermosyphon was proposed. The mathematical modeling of heat transfer and phase transitions of coolant in the thermosyphon was performed. The problem of heat transfer is formulated in dimensionless variables “velocity vorticity vector – current function – temperature” and solved by finite difference method. As a result of numerical simulation it is found that an increase in the vapor channel length from 0.15m to 1m leads to increasing the temperature difference by 3.5 K.

  4. Design and Testing for a New Thermosyphon Irradiation Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Felde, David K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carbajo, Juan J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McDuffee, Joel Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) requires most materials and all fuel experiments to be placed in a pressure containment vessel to ensure that internal contaminants such as fission products cannot be released into the primary coolant. It also requires that all experiments be capable of withstanding various accident conditions (e.g., loss of coolant) without generating vapor bubbles on the surface of the experiment in the primary coolant. These requirements are intended to artificially increase experiment temperatures by introducing a barrier between the experimental materials and the HFIR coolant, and by reducing heat loads to the HFIR primary coolant, thus ensuring that no boiling can occur. A proposed design for materials irradiation would remove these limitations by providing the required primary containment with an internal cooling flow. This would allow for experiments to be irradiated without concern for coolant contamination (e.g., from cladding failure of advanced fuel pins) or for specimen heat load. This report describes a new materials irradiation experiment design that uses a thermosyphon cooling system to allow experimental materials direct access to a liquid coolant. The new design also increases the range of conditions that can be tested in HFIR. This design will provide a unique capability to validate the performance of current and advanced fuels and materials. Because of limited supporting data for this kind of irradiation vehicle, a test program was initiated to obtain operating data that can be used to (1) qualify the vehicle for operation in HFIR and (2) validate computer models used to perform design- and safety-basis calculations. This report also describes the test facility and experimental data, and it provides a comparison of the experimental data to computer simulations. A total of 51 tests have been completed: four tests with pure steam, 12 tests with argon, and 35 tests with helium. A total

  5. Heat transfer characteristics of the two-phase closed thermosyphon (wickless heat pipe)

    International Nuclear Information System (INIS)

    Andros, F.E.; Florschuetz, L.W.

    1982-01-01

    Steady-state heat transfer characteristics and heat transfer limits (dry-out) for a vertical stainless steel tubular two-phase closed thermosyphon with Freon-113 working fluid are reported as a function of certain geometric parameters and liquid fill quantity. Condenser section heat transfer characteristics agreed reasonably well with existing laminar film condensation correlations and were found to be independent of the evaporator section, except for larger liquid fills. Evaporator characteristics were quite complex and appeared, under some conditions, to be coupled to condenser characteristics through effects of system pressure and/or surface wave as present on the descending condensate film. A laminar thin film evaporation model was found to give reasonable agreement with local evaporator temperature measurements in those regions of the evaporator where a continuous film apparently persisted. The measured heat transfer characteristics are interpreted relative to an earlier investigation by the authors in which flow characteristics in a similar device were visually and photographically observed. 10 references

  6. Development of dynamic simulator for thermosyphon evaporator process with an application

    International Nuclear Information System (INIS)

    Shimizu, Yoshiaki; Tsutsui, Tenson.

    1986-06-01

    A dynamic simulator has been developed for radwaste evaporator system in the Research Reactor Institute of Kyoto University. Under mild assumptions, two-phase flow model of the thermosyphon evaporator was shown to be modelled by a set of ordinary and algebraic equations. Through a structure analysis of such equations, a compact but efficient computer program was realized using FORTRAN computer language. By comparing numerical results with experimental ones, reliability of the model has been examined. Furthermore, mentioning several applications imbedded into the developed simulator, a bi-objective optimal problem was formulated generally, and then solved numerically through a practical procedure. It is expected that such a consideration is helpful for the radwaste management in practice. (author)

  7. Analysis of battery behavior in small photovoltaic systems; Analise do comportamento da bateria utilizada em sistemas fotovoltaicos de pequeno porte

    Energy Technology Data Exchange (ETDEWEB)

    Fraga, Jose Renato Castro Pompeia; Cagnon, Jose Angelo [Programa de Pos-Graduacao em Agronomia - Energia na Agricultura - FCA/UNESP, Botucatu, SP (Brazil); Dept. de Engenharia Eletrica - FEB/UNESP, Bauru, SP (Brazil)], e-mails: jrfraga@feb.unesp.br, jacagnon@feb.unesp.br

    2011-07-01

    This work aimed to analyze the electric energy storage system generated from a photovoltaic system with lead-acid batteries. The increasing claim for energy in the world in addition to the need of using renewable energy sources in order to preserve the environment makes necessary the development of efficient techniques of power supply and control. Two photovoltaic systems were used in this work, a conventional one with stationary solar panel and another with automatic solar position system. The comparative analysis has allowed assessing the advantages of both systems. The following characteristics were obtained during the development of this work: charge, discharge, battery capacity, operating time rate, auto-discharge reaction (through fluctuation state), among other important information that allows an extended life to the stationary battery studied. The obtained results indicate that the battery connected to the mobile system provides 36% of additional energy compared to the fixed system. When the battery was unable to provide energy to the load, the battery connected to the mobile system consumed about 33% less energy than that one connected to the fixed system (author)

  8. Exergoeconomic analysis and optimization of a model cogeneration system; Analise exergoeconomica e otimizacao de um modelo de sistema de cogeracao

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Leonardo S.R. [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil). Area de Conhecimento de Materiais e Mecanica]. E-mail: lsrv@cepel.br; Donatelli, Joao L.M. [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Engenharia Mecanica]. E-mail: donatelli@lttc.com.ufrj.br; Cruz, Manuel E.C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica]. E-mail: manuel@serv.com.ufrj.br

    2000-07-01

    In this paper we perform exergetic and exergoeconomic analyses, a mathematical optimization and an exergoeconomic optimization of a gas turbine-heat recovery boiler cogeneration system with fixed electricity and steam production rates. The exergy balance is calculated with the IPSE pro thermal system simulation program. In the exergetic analysis, exergy destruction rates, exergetic efficiencies and structural bond coefficients for each component are evaluated as functions of the decision variables of the optimization problem. In the exergoeconomic analysis the cost for each exergetic flow is determined through cost balance equations and additional auxiliary equations from cost partition criteria. Mathematical optimization is performed by the metric variable method (software EES - Engineering Equation Solver) and by the successive quadratic programming (IMSL library - Fortran Power Station). The exergoeconomic optimization is performed on the basis of the exergoeconomic variables. System optimization is also performed by evaluating the derivative of the objective function through finite differences. This paper concludes with a comparison between the four optimization techniques employed. (author)

  9. System for alarms analysis and optimization in petrochemicals plants; Sistema para analise e otimizacao de alarmes em plantas petroquimicas

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Gustavo; Pifer, Aderson; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Saito, Kaku; Aquino, Leonardo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The present work presents a group of algorithms, techniques and functionalities on alarms management which can be used efficiently on the treatment of 'disturbances' caused by the informal management of the alarm systems. Among the disturbances handled by these techniques, there is the recognition of intermittent alarms and false alarms, location of alarm floods and correlation between alarms, aiming the identification of communal root causes. The results will be presented through a case study on petrochemical alarm plants. At last, the results obtained by the utilization of such functionalities will be presented and discussed. (author)

  10. Optimization of a computer simulation code to analyse thermal systems for solar energy water heating; Aperfeicoamento de um programa de simulacao computacional para analise de sistemas termicos de aquecimento de agua por energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Pozzebon, Felipe Barin

    2009-02-15

    The potential of solar water heating systems through solar energy in Brazil is excellent due to the climatic features of the country. The performance of these systems is highly influenced also by the materials used to build it and by the dimension of its equipment and components. In face of global warming, solar energy gains more attention, since it is one of the renewable energy that will be largely used to replace some of the existing polluting types of energy. This paper presents the improvement of a software that conducts simulations of water heating systems using solar energy in thermosyphon regime or forced circulation. TermoSim, as it is called, was initiated at the Solar Labs, and is in its version 3.0. The current version is capable of simulating 6 different arrangements' possibilities combined with auxiliary energy: systems with solar collectors with auxiliary energy with gas, electric energy, internal electric energy, electric energy in series with the consumption line, and no auxiliary energy. The software is a tool to aid studies and analysis of solar heating systems, it has a friendly interface that is easy to comprehend and results are simple to use. Besides that, this version also allows simulations that consider heat losses at night, situation in which a reverse circulation can occur and mean efficiency loss, depending on the simulated system type. There were many simulations with the mathematical models used and comparisons were made with the climatic data of the city of Caxias do Sul, in Rio Grande do Sul state, in Brazil, determining the system with the most efficient configuration for the simulated water consume profile. The paper is finalized with simple economic analyses with the intention of foreseeing the time for payback on the investment, taking into account the current prices for electrical energy in the simulated area and the possible monthly economy provided with the use of a solar energy heating system. (author)

  11. Numerical study on heat transfer characteristics of thermosyphon heat pipes using nanofluids

    International Nuclear Information System (INIS)

    Huminic, Gabriela; Huminic, Angel

    2013-01-01

    Highlights: • Numerical study of nanofluid heat transfer in thermosyphon heat pipes is performed. • Effect of nanoparticle concentration and operating temperature are studied. • Fe 2 O 3 –water nanofluid with 5.3% volume concentration shows the best performance. • Results show the improvement the thermal performances of thermosyphon heat pipe with nanofluids. - Abstract: In this work, a three-dimensional analysis is used to investigate the heat transfer of thermosyphon heat pipe using water and nanofluids as the working fluid. The study focused mainly on the effects of volume concentrations of nanoparticles and the operating temperature on the heat transfer performance of the thermosyphon heat pipe using the nanofluids. The analysis was performed for water and γ-Fe 2 O 3 nanoparticles, three volume concentrations of nanoparticles (0 vol.%, 2 vol.% and 5.3 vol.%) and four operating temperatures (60, 70, 80 and 90 °C). The numerical results show that the volume concentration of nanoparticles had a significant effect in reducing the temperature difference between the evaporator and condenser. Experimental and numerical results show qualitatively that the thermosyphon heat pipe using the nanofluid has better heat transfer characteristics than the thermosyphon heat pipe using water

  12. Effect of non-condensable gas on steady-state operation of a loop thermosyphon

    International Nuclear Information System (INIS)

    He, Jiang; Lin, Guiping; Bai, Lizhan; Miao, Jianyin; Zhang, Hongxing; Wang, Lu

    2014-01-01

    Non-condensable gas (NCG) generated inside two-phase heat transfer devices can adversely affect the thermal performance and limit the lifetime of such devices. In this work, extensive experimental investigation of the effect of NCG on the steady-state operation of an ammonia-stainless steel loop thermosyphon was conducted. In the experiments, nitrogen was injected into the loop thermosyphon as NCG, and the thermal performance of the loop thermosyphon was tested at different NCG inventories, heat loads applied to the evaporator and condenser cooling conditions, i.e. natural air cooling or circulating ethanol cooling. Experimental results reveal that NCG elevates the steady-state operating temperature of the evaporator, especially when the loop thermosyphon is operating in the low temperature range; meanwhile, the more NCG exists in the loop thermosyphon, the higher the operating temperature of the evaporator, and the lower the reservoir temperature. In addition, the existence of NCG results in the decrease of the overall thermal conductance of the loop thermosyphon, and the overall thermal conductance under the ethanol cooling condition may be even lower than that under the air cooling condition when the heat load is smaller than a certain value. Finally, the experimental results are theoretically analysed and explained. (authors)

  13. Oscillation phenomena and operating limits of the closed two-phase thermosyphon

    International Nuclear Information System (INIS)

    Fukano, T.; Kadoguchi, K.; Tien, C.L.

    1986-01-01

    In a vertical thermosyphon an up-going vapor flow prevents a liquid film from flowing downward and causes flooding if the heat input exceeds a certain value. Then the evaporator wall partially dries out. The wall temperature in the evaporator and the system pressure are measured and their post-dryout behavior is classified into three types: (1) the periodic oscillation, and transient variations going asymptotically to (2) the higher and (3) the lower than the initial system pressure setting. The occurrence of the first type, periodic oscillation, is limited to when the amount of working fluid, methanol, is about one-third of the evaporator volume. To explain these changes in the system pressure and wall temperature a physical model, based on the alternating flooding and deflooding concept is proposed. In this work the effect of the tube diameter, amount of working fluid, and system pressure on these oscillations and the flow and heat transfer characteristics during the oscillations are also experimentally investigated

  14. The onset of flows and instabilities in a thermosyphon with parallel loops

    International Nuclear Information System (INIS)

    Zvirin, Y.

    1986-01-01

    A theoretical study is presented for the stability of various steady flows in a thermosyphon with multiple vertical channels. The main interest is in the onset of motion from a rest state or in a stagnant branch, therefore laminar flow is considered and a one-dimensional model is used to describe the flow and temperature fields. The steady state solutions include a state of no flow (rest) in the whole system and two basic flow configurations: a single loop between two channels while the others are stagnant and a symmetric flow. For a three-channel system the latter consists of an upward velocity in one branch and downward velocities in the other two. The mirror image of these basic flows are also steady state solutions. A critical modified number is found to be the stability margin for the onset of motion from a rest state in the entire system. This result was obtained both by a study of the steady state solution and by the stability analysis. The steady flow with a stagnant loop is always unstable while the symmetric flow solution in the system considered here is always stable. (orig./HP)

  15. BESKRYWING VAI'l TEGNIEKE EN CHEMIESE ANALISES VAN ...

    African Journals Online (AJOL)

    afwykings en koefftsiente van variasie tussen monsters en tussen analises binne monsters verstrek. Tussen monsters verteenwoordig die verskille tussen diere en tussen ana- lises binne monsters verteenwoordig die verskille tussen herhalings binne dieselfde monstefS en dui dus die akku- raatheid van die analises aan.

  16. Theoretical and experimental investigation of the performance of solar thermosyphon heat pipe

    International Nuclear Information System (INIS)

    Hamidi, A.A.; Khalji Asadi, M.; Yousefi, L.; Moeini, G.

    2001-01-01

    Thermosyphon is a kind of heat pipe consisting of a tube which after through degassing has been filled with the required working fluid under vacuum, the pipe is equipped with wide fines on both sides in order to absorb solar radiation effectively. In order to eliminate conduction and convection heat transfer phenomena the tube is situated inside an evacuated glass bulb. In order to increase the efficiency and improve the design and working conditions of various types of heat pipes, a fundamental knowledge of the variation of operating parameters inside the heat pipes is necessary. In this paper, effective operating parameters of a thermosyphon heat pipe in uniform and steady condition are studied. These parameters include saturation temperature of the fluid inside the pipe, the variation of liquid and vapor flow rates inside the pipe and finally the pressure drop of liquid and vapor along the length of the pipe. The modeling is first started by writing an energy balance for the control volume of the pipe so that a first approximation for the above mentioned parameters is obtained. In this balance, depending on the type of fluid next to the condenser section and the type of heat transfer phenomena (free or forced convection) and also with due regards to the experimental correlations available, first the Nusselt number and then the heat transfer coefficient is calculated. From the latter, a first estimate of the required values for the liquid and vapor flow rates are found to be 0.222 and 0.0001126 Kg/s, respectively. The thickness of the film was determined to be 0.2 mm. In order to calculate the variations of the above mentioned parameters along the length of the tube, mass heat and momentum balances were written in next step for the control volumes on the liquid film, vapor phase and the system as a whole. Diagrams of these variations were obtained. The results were compared with both the data available in the literature and the experimental findings of a heat

  17. Successful pilot of thermosyphon process heater reduces GHG emissions and operating costs

    International Nuclear Information System (INIS)

    Arnold, W.A.; Neulander, J.I.

    1999-01-01

    A joint pilot study was conducted by Hudson Products Corporation and PanCanadian Petroleum Ltd. to test the feasibility of using a thermosyphon as a part of a thermal recovery process for cold heavy oil reservoir exploitation in the Western Canada Sedimentary Basin. A thermosyphon process heater can transfer heat from an external combustion chamber to a liquid inside a tank. This paper described the pilot project in which such a heater was successfully tested in a heavy oil field production tank. The field trial was conducted at the Marwayne Field in northeastern Alberta. The results of the pilot study demonstrated that the thermosyphon not only improved process efficiency, but also reduced greenhouse gas (GHG) emissions, lowered operating costs and improved safety. 5 refs., 3 tabs., 1 fig., 3 appendices

  18. Vapordynamic thermosyphon - heat transfer two-phase device for wide applications

    Science.gov (United States)

    Vasiliev, Leonard; Vasiliev, Leonid; Zhuravlyov, Alexander; Shapovalov, Aleksander; Rodin, Aleksei

    2015-12-01

    Vapordynamic thermosyphon (VDT) is an efficient heat transfer device. The two-phase flow generation and dynamic interaction between the liquid slugs and vapor bubbles in the annular minichannel of the VDT condenser are the main features of such thermosyphon, which allowed to increase its thermodynamic efficiency. VDT can transfer heat in horizontal position over a long distance. The condenser is nearly isothermal with the length of tens of meters. The VDT evaporators may have different forms. Some practical applications of VDT are considered.

  19. Application of a two-phase thermosyphon loop with minichannels and a minipump in computer cooling

    Directory of Open Access Journals (Sweden)

    Bieliński Henryk

    2016-03-01

    Full Text Available This paper focuses on the computer cooling capacity using the thermosyphon loop with minichannels and minipump. The one-dimensional separate model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels and minipump has been used in calculations. The latest correlations for minichannels available in literature have been applied. This model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser and the falling tube. A numerical analysis of the mass flux and heat transfer coefficient in the steady state has been presented.

  20. Closed Loop Two-Phase Thermosyphon of Small Dimensions: a Review of the Experimental Results

    Science.gov (United States)

    Franco, Alessandro; Filippeschi, Sauro

    2012-06-01

    A bibliographical review on the heat and mass transfer in gravity assisted Closed Loop Two Phase Thermosyphons (CLTPT) with channels having a hydraulic diameter of the order of some millimetres and input power below 1 kW is proposed. The available experimental works in the literature are critically analysed in order to highlight the main results and the correlation between mass flow rate and heat input in natural circulation loops. A comparison of different experimental apparatuses and results is made. It is observed that the results are very different among them and in many cases the experimental data disagree with the conventional theory developed for an imposed flow rate. The paper analyses the main differences among the experimental devices and try to understand these disagreements. From the present analysis it is evident that further systematic studies are required to generate a meaningful body of knowledge of the heat and mass transport mechanism in these devices for practical applications in cooling devices or energy systems.

  1. Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants

    Science.gov (United States)

    Gorecki, Grzegorz

    2018-02-01

    Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).

  2. Heat transfer and thermal storage performance of an open thermosyphon type thermal storage unit with tubular phase change material canisters

    International Nuclear Information System (INIS)

    Wang, Ping-Yang; Hu, Bo-Wen; Liu, Zhen-Hua

    2015-01-01

    Highlights: • A novel open heat pipe thermal storage unit is design to improve its performance. • Mechanism of its operation is phase-change heat transfer. • Tubular canisters with phase change material were placed in thermal storage unit. • Experiment and analysis are carried out to investigate its operation properties. - Abstract: A novel open thermosyphon-type thermal storage unit is presented to improve design and performance of heat pipe type thermal storage unit. In the present study, tubular canisters filled with a solid–liquid phase change material are vertically placed in the middle of the thermal storage unit. The phase change material melts at 100 °C. Water is presented as the phase-change heat transfer medium of the thermal storage unit. The tubular canister is wrapped tightly with a layer of stainless steel mesh to increase the surface wettability. The heat transfer mechanism of charging/discharging is similar to that of the thermosyphon. Heat transfer between the heat resource or cold resource and the phase change material in this device occurs in the form of a cyclic phase change of the heat-transfer medium, which occurs on the surface of the copper tubes and has an extremely high heat-transfer coefficient. A series of experiments and theoretical analyses are carried out to investigate the properties of the thermal storage unit, including power distribution, start-up performance, and temperature difference between the phase change material and the surrounding vapor. The results show that the whole system has excellent heat-storage/heat-release performance

  3. A study of flow patterns in a thermosyphon for compact heat exchanger applications

    NARCIS (Netherlands)

    Grooten, M.H.M.; Geld, van der C.W.M.; Deursen, van L.G.M.

    2008-01-01

    Recently, thermosyphons have attracted interest in the design of smaller, lighter and cheaper heat exchangers, because of their compactness, low thermal resistance, high heat recovery effectiveness, safety and reliability. In order to understand the effects of the angle of inclination on heat

  4. A new computer system for security analysis in power systems; Um novo sistema computacional para analise de seguranca em sistemas de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Vicente Canto dos; Gerhardt, Raul A.; Costa, Iverson F. [Universidade do Vale do Rio dos Sinos (PIPCA/UNISINOS), Sao Leopoldo, RS (Brazil). Programa de Pos-Graduacao em Computacao Aplicada], E-mail: jvcanto@unisinos.br

    2009-07-01

    In the electrical energy systems area, the problem of security analysis have been intensively studied in the last years. The main objective of this work has been the developing of a new computational system for static security analysis. Moreover, the considered system incorporates elements that they look to increase its adequacy to the real use in electrical utilities. The ample literature review achieved by the authors has showed that no analogous proposal was found. To validate the proposed system, the results of tests made on several power systems were described, including a real life Brazilian system of large dimensions. (author)

  5. Experimental Study of Silicon Oil Effect on Two-Phase Closed Thermosyphon

    International Nuclear Information System (INIS)

    Jung, Jun Yeong; Jeong, Yong Hoon

    2015-01-01

    Two-phase closed thermosyphon (TPCT) is vertically oriented wickless heat pipe that has working fluid in the interior. The TPCT transports a large amount of heat from evaporator to condenser by phase change of working fluid, and the working fluid passively returns to evaporator by gravity. Due to these advantages of the TPCT, the TPCT is considered as method of PRHR (Passive Residual Heat Removal) system in nuclear system. Parametric studies have done to investigate the heat transfer characteristics of the TPCT. Different working fluids such as water, ethanol, methanol and acetone were used at various filling ratios and at different operating temperatures to find maximum heat transport capabilities of TPCT. Effect of heat transfer rate, filling ratio and aspect ratio were investigated. Inclined angle effect was investigated at several filling ratios and working fluids. This study is interested in silicon oil effect on the TPCT. To carry out the experiment, experimental apparatus is designed and manufactured. In design process, the TPCT operation limit is considered This study is interested in silicon oil effect on the TPCT. Experiments were carried out at three oil weight percent with three input power. Effect of oil on the TPCT is evaluated by inner wall temperature distribution and thermal resistance. In this study, silicon oil effect on TPCT was investigated. The TPCT was operated with several oil weight percent and input power. From experiment, overall, the silicon oil reduced evaporator thermal performance, but enhanced condenser thermal performance. However, the TPCT total thermal performance was reduced by 100 c St silicon oil

  6. Experimental Study of Silicon Oil Effect on Two-Phase Closed Thermosyphon

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jun Yeong; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Two-phase closed thermosyphon (TPCT) is vertically oriented wickless heat pipe that has working fluid in the interior. The TPCT transports a large amount of heat from evaporator to condenser by phase change of working fluid, and the working fluid passively returns to evaporator by gravity. Due to these advantages of the TPCT, the TPCT is considered as method of PRHR (Passive Residual Heat Removal) system in nuclear system. Parametric studies have done to investigate the heat transfer characteristics of the TPCT. Different working fluids such as water, ethanol, methanol and acetone were used at various filling ratios and at different operating temperatures to find maximum heat transport capabilities of TPCT. Effect of heat transfer rate, filling ratio and aspect ratio were investigated. Inclined angle effect was investigated at several filling ratios and working fluids. This study is interested in silicon oil effect on the TPCT. To carry out the experiment, experimental apparatus is designed and manufactured. In design process, the TPCT operation limit is considered This study is interested in silicon oil effect on the TPCT. Experiments were carried out at three oil weight percent with three input power. Effect of oil on the TPCT is evaluated by inner wall temperature distribution and thermal resistance. In this study, silicon oil effect on TPCT was investigated. The TPCT was operated with several oil weight percent and input power. From experiment, overall, the silicon oil reduced evaporator thermal performance, but enhanced condenser thermal performance. However, the TPCT total thermal performance was reduced by 100 c St silicon oil.

  7. A study on the performance of condensation heat transfer for various working fluid of two-phase closed thermosyphons with various helical grooves

    International Nuclear Information System (INIS)

    Han, Kyu Il; Cho, Dong Hyun

    2005-01-01

    This study concerns the performance of condensing heat transfer in two-phase closed thermosyphons with various helical grooves. Distilled water, methanol, ethanol have been used as the working fluid. In the present work, a copper tube of the length of 1200mm and 14.28mm of inside diameter is used as the container of the thermosyphon. Each of the evaporator and the condenser section has a length of 550mm, while the remaining part of the thermosyphon tube is adiabatic section. A experimental study was carried out for analyzing the performances of having 50, 60, 70, 80, 90 helical grooves. A plain thermosyphon having the same inner and outer diameter as the grooved thermosyphons is also tested for the comparison. The type of working fluid and the numbers of grooves of the thermosyphons with various helical grooves have been used as the experimental parameters. The experimental results have been assessed and compared with existing theories. The results show that the type of working fluids are very important factors for the operation of thermosyphons. And the maximum enhancement (i.e. the ratio of the heat transfer coefficients the helical thermosyphons to plain thermosyphons) is 1.5∼2 for condensation

  8. Effect of nanofluid concentration on two-phase thermosyphon heat exchanger performance

    OpenAIRE

    Cieśliński Janusz T.

    2016-01-01

    An approach - relaying on application of nanofluid as a working fluid, to improve performance of the two-phase thermosyphon heat exchanger (TPTHEx) has been proposed. The prototype heat exchanger consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. Distilled water and nanofluid water-Al2O3 solution were used as working fluids. Nanoparticles were tested a...

  9. Temperature control of paddy bulk storage with aeration-thermosyphon heat pipe

    International Nuclear Information System (INIS)

    Dussadee, Natthawud; Punsaensri, Tammasak; Kiatsiriroat, Tanongkiat

    2007-01-01

    A technology of an aeration-thermosyphon heat pipe is developed for controlling paddy temperature in a paddy bulk silo. A prototype of paddy bulk storage of 1000 kg has a set of copper tubes with steel fins embedded in the paddy bed. The total heat transfer area of the tubes with fins is 16 m 2 . The tubes act as the evaporator of a thermosyphon heat pipe and absorb heat resulting from the paddy respiration. The thermosyphon has a total condenser area of 12.2 m 2 that is exposed to ambient air. At the bottom of the silo, ambient air is fed upward through the paddy bed for the aeration. The initial moisture content of the paddy is around 12.8% wet basis. A mathematical model to predict the paddy bed temperature in the silo with the hybrid aeration-thermosyphon is developed, and the results agree very well with the experimental data. The operating period of its blower could be found from the simulation. The blower is on when the paddy bed temperature, T b , is over or equal to 28 deg. C and the difference temperature between the bed and the ambient, T d , is over or equal to 1 deg. C. The appropriate evaporator area should be over 8 m 2 . At the area of 8 m 2 , the operation time of the blower is 8-9% of the annual period compared with 30-40% for normal aeration alone. The monthly paddy bed temperature could be maintained between 24 and 27 deg. C under the climate of Chiang Mai, Thailand

  10. Experimental study for transient response of a double-tube thermosyphon (DTTH)

    International Nuclear Information System (INIS)

    Salem, M.A.M.

    2010-01-01

    Energy conservation is becoming increasingly important as the cost of fuel continuously rises. The heat pipe and the closed two-phase thermosyphon are particularly effective tools in the heat transfer process.A theoretical and experimental investigation was conducted to study the double-tube two-phase closed-thermosyphon (DTTH) behavior in transient regimes. Experiments were performed to investigate the effects of changing the heating and cooling rate as well as the evaporator length on the double tube thermosyphon in actual integrated operation (start-up, steady-state and shut-down). he necessity for a dynamic model of DTTH for some applications of discontinuous operation imposed the need to the current applied investigation. Therefore, the main objective of the current study is to develop a theoretical model that can predict the dynamic behavior of the double-tube evaporator by tracing various transient parameters during operation from start up to steady state until shut down condition. A model describing both thermal and phase flows of the closed two-phase double tube thermosyphon (DTTH) has been simulated. The theoretical model provides a general description of the behavior of our practical setup based on experimental observations which show a simple exponential behavior. It is based on a two thermal body description (evaporator wall and working fluid) there is good agreement between experiments data and numerical prediction.A computer simulation program based on the method was developed to estimate temperature and the other performance of double tube thermosyphon as well as the time needed to reach steady state condition. The governing equations of the simple 1-D model were solved by Engineering Equation Solver program (EES) using finite difference Euler method. A computer program is designed to solve these differential equations by an explicit finite difference method. The results from this model were found to be in general agreement with the experimental

  11. Experimental analysis to improving thermosyphon (TPCT) thermal efficiency using nanoparticles/based fluids (water)

    Science.gov (United States)

    Hoseinzadeh, S.; Sahebi, S. A. R.; Ghasemiasl, R.; Majidian, A. R.

    2017-05-01

    In the present study an experimental set-up is used to investigate the effect of a nanofluid as a working fluid to increase thermosyphon efficiency. Nanofluids are a new form of heat transfer media prepared by suspending metallic and nonmetallic nanoparticles in a base fluid. The nanoparticles added to the fluid enhance the thermal characteristics of the base fluid. The nanofluid used in this experiment was a mixture of water and nanoparticles prepared with 0.5%, 1%, 1.5%, or 2% (v) concentration of silicon carbide (SiC) nanoparticles and 1%, 2% and 3% (v) concentration of aluminum oxide (Al2O3) in an ultrasonic homogenizer. The results indicate that the SiC/water and Al2O3/water nanofluids increase the thermosyphon performance. The efficiency of the thermosyphon using the 2% (v) (SiC) nanoparticles nanofluid was 1.11 times that of pure water and the highest efficiency occurs for the 3% (Al2O3) nanoparticle concentration with input power of 300 W. The decrease in the temperature difference between the condenser and evaporator confirms these enhancements.

  12. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  13. Analysis of the thermal performance of a solar heating system using a collector with absorbing surface in plates coated with PVC; Analise do desempenho termico de um sistema de aquecimento solar utilizando coletor com superficie absorvedora em chapas de forro de PVC

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Edmilson Pedreira dos

    2009-08-15

    It is presented a solar collector to be used in a system for heating bath water, whose main characteristic is its low cost. The collector consists of five plates of PVC with 10 mm thick, 200 mm wide and 1400 mm length, with ao area equal to 1,4 square meters. The plates were connected in parallel to the ends of PVC tubes of 40 mm diameter and 32 mm diameter. The plates were coated on one side with aluminum sheets of soft drinks and beers cans open. The system worked on a thermosyphon and was tested in two configurations: the plates uncoated and coated with aluminum material, to determine the influence of material on the efficiency of the collector. For both configurations was used EPS plates below the surface to minimize heat losses from the bottom. The thermal reservoir of the heating system is, also, alternative and of low cost, since it was constructed from a polyethylene tank for storing water, with volume of 150 end 200 liters. It will be presented the thermal efficiency, heat loss, water temperature of the thermal reservoir at the end of the process and simulation of baths for a house with four residents. It will be demonstrated the thermal, economic and material viability of the proposed collector, whose main innovation is the use of recyclable materials, cans of beer and soft drinks, to increase the temperature of the absorber plate. (author)

  14. Exergetic analysis of the operation of a petrochemical pole cogeneration system; Analise exergetica da operacao de uma planta de cogeracao de um polo petroquimico

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Ednildo A. [Bahia Univ., Salvador, BA (Brazil). Escola Politecnica]. E-mail: ednildo@ufba.br; Gallo, Waldyr L. R. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: gallo@unicamp.br

    2000-07-01

    This work presents an exergy analysis for a petrochemical cogeneration system (the greater operating in Brazil). The system is described, the method employed to simulate the system is presented, and the exergy efficiencies are defined. The analysis presents the exergy efficiencies and irreversibility for each sub-system. The results obtained from real data were used to compare operation strategies which are not clear from energy balances. (author)

  15. Monobuoy monitoring system - project, installation and preliminary results; Sistema de monitoracao de monoboias maritimas - desenvolvimento, instalacao e analise preliminar de resultados

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Daniel L; Machado Filho, Remo Z [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Medeiros, Junior, Adory J [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    A monobuoy monitoring system was developed and installed on 2004 in two oil terminals of TRANSPETRO. The main purpose of this system is to assure that monobuoys will be assisted during offloading operations, which will reduce the risk of accidents and detect immediately damages on mooring lines and equipment. The system comprises a Control Module on terminal site and a Remote Monitoring Unit, installed on each monobuoy. The link between modules is provided by an UHF radio-modem. The parameters acquired are pitch, roll, heave, geographic position, internal variables, and, if available, pressure and temperature of lines, traction on mooring system, etc. Positioning information is processed by the PETRONAV Positioning System. The whole process is registered and monitored on terminal with graphical interface. This article describes the development and installation of the system and the preliminary analysis of data produced since the system was installed. (author)

  16. Multicriteria analysis of the hybrid systems with biogas: fuzzy set and rules; Analise multicriterio de sistemas hibridos com biogas: conjuntos e regras fuzzy

    Energy Technology Data Exchange (ETDEWEB)

    Barin, A.; Canha, L.; Abaide, A.; Magnago, K. [Federal University of Santa Maria (UFSM), RS (Brazil)], E-mail: chbarin@gmail.com; Machado, R. [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia], E-mail: rquadros@sel.eesc.usp.br

    2009-07-01

    A multicriteria analysis to manage de renewable sources of energy is presented, identifying the most appropriate hybrid system to be used as distributed generation of electric energy using biogas. In this methodology, fuzzy sets and rules are defined simulated in the software MATLAB, where the main characteristics of the operation and application of hybrid systems of electric power generation are considered. The main generation system, that can use the biogas, as micro turbines and fuel cells, are evaluated. Afterwards, the systems of energy storage are analyzed: flywheel, H{sub 2} storage and conventional and redox batteries. For the development of the proposed methodology, it was considered the following criteria: efficiency, costs, technological maturity, environmental impacts, the amplitude of the system action (power range), useful life, co-generation possibility and operation temperature. A classification, by priority order, for the use of the sources and storages associated to the environment and cost scenarios is also presented.

  17. Analysis of cogeneration system using fuel cell: cases study; Analise de sistema de cogeracao utilizando celula de combustivel: estudo de casos

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Jose Luz; Leal, Elisangela Martins [UNESP, Guaratingueta, SP (Brazil). Escola de Engenharia. Dept. de Energia]. E-mails: joseluz@feg.unesp.br; elisange@feg.unesp.br

    2000-07-01

    In this paper, a methodology for the study of a molten carbonate fuel cell cogeneration system associated to an absorption refrigeration system, for the electricity and cold water production, and applied to two establishments, is presented. This system permits the recovery of waste heat, available between 600 deg C e 700 deg C. Initially, some technical information about the most diffusing types of the fuel cell demonstration in the world are presented. In the next step, an energetic, exergetic and economic analysis are carry out, seeking the use of fuel cells, in conditions of prices and interest of Brazil. In conclusion, the fuel cell cogeneration system may have an excellent opportunity to strengthen the decentralized energy production in the Brazilian energy scene. (author)

  18. Analysis and simulation of water supply systems with photovoltaic pumping; Analise e simulacao de sistemas de abastecimento de agua com tecnologia fotovoltaica

    Energy Technology Data Exchange (ETDEWEB)

    Vilela, Olga de Castro

    1996-09-01

    During the last two decades, a remarkable progress on the technology of photovoltaic pumping systems (PVP) has been observed. The decrease in the costs of the photovoltaic module and the increase in the efficiency of photovoltaic pumping systems (generator and motor-pump) make PVP systems a good option for rural communities. Most analysis and simulations of PVP systems, utility function, assume the existence of a linear relationship between the hydraulic power and the solar collected radiation. Usually, more general relations exist between those variables. This work presents a new procedure for the analysis and simulation of PVP systems, which uses the utility function to consider the fluctuations in solar radiation, and leads to analytical solutions for PVP systems whose behavior can be represented by general functions, including linear relations as a particular case. The system analyzed considers the energy source (solar radiation) and the components of the water supply system like water source, photovoltaic array, subsystem for conversion of electric into hydraulic energy and, finally, hydraulic network. An analytical procedure to calculate absorbed solar radiation in the optical layers of the photovoltaic module was developed, substituting the conventional ray tracing method. The volume of pumped water was obtained integrating the water flow rate through time, considering the fluctuations related to the behavior of solar radiation and the minimum level of radiation necessary to produce useful energy. The mathematical properties of the utility function allow to derive analytical solutions for the integrals of water flow and hydraulic power. At the same time, we developed a spreadsheet which allows tho visualize the behavior of all variables involved in the process and offers the possibility of simulating different situations in order to maximize the amount of pumped water for any given system. The results obtained through the new procedure were compared with

  19. Transference and natural gas distribution system analysis utilizing hybrid modelling; Analise de sistemas de transferencia e distribuicao de gas natural utilizando modelagem hibrida

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Robson A.; Martinkoski, Ricardo [Centro Federal de Educacao Tecnologica do Parana (CEFET), Curitiba, PR (Brazil); Neves Junior, Flavio [Centro Federal de Educacao Tecnologica do Parana (CEFET), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial

    2003-07-01

    The objective of this article is to apply techniques of formal specification in modelling of natural gas transmission and distribution systems. In this case the formal models are characterized by using hybrid automata. Initially the existent components in the net are modeled and represented by independent hybrid automata. The global dynamics is obtained through the product hybrid automata. Languages representing the desirable states of the system are obtained from the hybrid automata, allowing a hybrid control procedure. An automatic tool as SHIFT must be used to modelling and simulation. (author)

  20. Comparative analysis of cost benefit division methodologies in a hydrothermal generation system; Analise comparativa de metodologias de reparticao de custos e beneficios num sistema de geracao hidrotermico

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, M V.F. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil); Gorenstin, B G; Campodonico, N M; Costa, J.P. da; Kelman, J [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil)

    1990-12-31

    The development and operation planning of the Brazilian generation system has been realized in a coordinate way by several years, due to some organizations, where the main generating companies from the country take part. The benefit share of the system to each participant of the planning and integrated operation has aroused interest. This paper describes the alternate forms of cost benefit allocation, between the participant companies of a coordinate operation, in order to reach an adequateness of remuneration and incentives. It was analysed two proposal of benefit allocation for energy export/import contracts: share by generation value and share by marginal benefit, concluding that the second one represents the best way of contribution for the several factors that comprising a hydroelectric power plant (storage capacity, effective storage and turbine capacity). (C.G.C.). 1 tab.

  1. A water heating system analysis for rural residences, using solar energy; Analise de um sistema de aquecimento de agua para residencias rurais, utilizando energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Basso, Luiz H.; Souza, Samuel N.M. de; Siqueira, Jair A.C.; Nogueira, Carlos E.C.; Santos, Reginaldo F. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Programa de Pos-Graduacao em Engenharia Agricola], emails: melegsouza@yahoo.com, ssouza@unioeste.br, jairsiqueira@unioeste.br, cecn1@yahoo.com.br, rfsantos@unioeste.br

    2010-01-15

    The awareness of the importance of the environment has stimulated the study of new renewed energy sources and less pollutant. Amongst these sources, solar energy stands alone for being perennial and clean. The use of solar energy in systems of agricultural residential water heating, can complement the economy of electric energy, base of the Brazilian energy matrix. Knowing the factors that influence the operation of a system of water heating by solar energy is important in determining their technical viabilities targeting their distribution in agricultural residences. To evaluate equipment of water heating for solar energy, a prototype was constructed in the campus of Assis Gurgacz College, in Cascavel,State of Parana, Brazil, with similar characteristics to equipment used in residences for two inhabitants, to function with natural circulation or thermo siphon and without help of a complementary heating system. The equipment revealed technical viability, reaching the minimum temperature for shower, of 35 deg C, whenever the solar radiation was above the 3,500 Wh m{sup -2}, for the majority of the studied days. (author)

  2. Transient stability analysis in electric power systems with frequency dependent loads; Analise de estabilidade transitoria em sistemas eletricos de potencia com cargas dependentes da frequencia

    Energy Technology Data Exchange (ETDEWEB)

    Alberto, Luis F. Costa; Borelli, Jose Renato; Bretas, Newton G. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Dept. de Engenharia Eletrica

    1997-12-31

    The power system models normally used to transient stability analysis are very simplified. Damping effects such as frequency dependent loads are neglected. In order to incorporate these effects in the analysis, a frequency dependent load model is proposed, and it is shown the important influence that it causes in the critical clearing times for stability analysis beyond the first swing. this load model require the network structure preservation and the knowledge of frequency of non-generator buses. In this work, an efficient method to estimate the frequencies of non-generator buses was developed. (author) 11 refs., 5 figs., 2 tabs.; e-mail: ngbretas at sel.eesc.sc.usp.br

  3. Models of neural networks for image analysis of cintillography from the urinary system; Modelos de redes neurais para analise de imagens cintilograficas do sistema urinario

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Paulo Sergio de Souza; Silva, Jorge Wagner Esteves da; Schirru, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: wagner@lmp.ufrj.br; schirru@lmp.ufrj.br

    2000-07-01

    From the several available diagnostic techniques, the non-invasive ones are the less aggressive to the human body. The use of radionuclides for renal function evaluation seems to be more secure than the other diagnostic procedures. However, the use of radioactive materials, makes it necessary to maximize the beneficial effects of this technique, conducing inevitably to the development of support tools for the analysis of their results. The objective of this work is to improve a system model for image analysis of scintillation. The detection and identification of renal anomalies is done by means of analysis of parts of the image, taking in account the spatial distribution of those anomalies. Geometric operations in conjunction with the segmentation technique enable the improvement of image analysis information processing. In this work, we look for the best artificial neural network architectures to introduce the knowledge of the medical expert into the diagnostic system. The search of the best neural network architectures, the geometric techniques and the image segmentation technique permitted a significant improvement of diagnostic analysis model by using scintillation. (author)

  4. Thermosyphon analysis of a repository: A simplified model for vapor flow and heat transfer

    International Nuclear Information System (INIS)

    Manteufel, R.D.; Powell, M.W.

    1994-01-01

    A simplified model is developed for thermally-driven buoyant gas flow in an unsaturated repository such as that anticipated at Yucca Mountain. Based on a simplified thermosyphon model, the strength of buoyant gas flow is related to key thermal-hydraulic parameters (e.g., bulk permeability and maximum repository temperature). The effects of buoyant gas flow on vapor flow and heat transport near the repository horizon are assessed, namely: (i) the strength of buoyant flow through the repository, (ii) the effect of buoyant flow on vapor transfer, and (iii) the effect of buoyant flow on heat transfer

  5. Critical analysis of the positioning of monitoring system of the cyclotron accelerator; Analise critica do posicionamento de um sistema de monitoramento de acelerador Ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Julia A.; Passaro, Bruno M.; Guimaraes, Maria Ines C.C.; Buchpigue, Carlos A. [Centro de Medicina Nuclear (CMN) do InRad HCFMUSP, Sao Paulo, SP (Brazil); Videira, Heber S., E-mail: heber@cyclopet.com [CYCLOPET Radiofarmacos LTDA., Curitiba, PR (Brazil)

    2012-08-15

    Ever since the first concerns arose about the possibility that the ionizing radiation induced detriment to human health, were created the methods of production, characterization and measurement of radiation, as well as definition of quantities that realistically express its interaction with human tissue. From this point, the monitoring program of the installation of a cyclotron must be continuously performed and contain the critical points of contamination according to the CNEN standard N.E. 3.02 - Radioprotection Service to avoid contamination and maintain radioactive exposure rates as low as reasonably achievable. The results obtained during the analysis showed that the positioning of monitors is suitable, except for the physico-chemical control laboratory monitors, which were installed next to the chapel of manipulation and below the dose calibrator. The answer obtained from the monitoring system in the position that the ionization chamber is in the door of the bunker should be taken into account, because the intensity of radiation emitted by the activation of the targets is slightly attenuated by the cyclotron. (author)

  6. Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

    DEFF Research Database (Denmark)

    Taherian, H.; Kolaei, Alireza Rezania; Sadeghi, S.

    2011-01-01

    This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center...

  7. Experimental investigation of small diameter two-phase closed thermosyphons charged with water, FC-84, FC-77 and FC-3283

    International Nuclear Information System (INIS)

    Jouhara, Hussam; Robinson, Anthony J.

    2010-01-01

    An experimental investigation of the performance of thermosyphons charged with water as well as the dielectric heat transfer liquids FC-84, FC-77 and FC-3283 has been carried out. The copper thermosyphon was 200 mm long with an inner diameter of 6 mm, which can be considered quite small compared with the vast majority of thermosyphons reported in the open literature. The evaporator length was 40 mm and the condenser length was 60 mm which corresponds with what might be expected in compact heat exchangers. With water as the working fluid two fluid loadings were investigated, that being 0.6 ml and 1.8 ml, corresponding to approximately half filled and overfilled evaporator section in order to ensure combined pool boiling and thin film evaporation/boiling and pool boiling only conditions, respectively. For the Fluorinert TM liquids, only the higher fill volume was tested as the aim was to investigate pool boiling opposed to thin film evaporation. Generally, the water-charged thermosyphon evaporator and condenser heat transfer characteristics compared well with available predictive correlations and theories. The thermal performance of the water-charged thermosyphon also outperformed the other three working fluids in both the effective thermal resistance as well as maximum heat transport capabilities. Even so, FC-84, the lowest saturation temperature fluid tested, shows marginal improvement in the heat transfer at low operating temperatures. All of the tested Fluorinert TM liquids offer the advantage of being dielectric fluids, which may be better suited for sensitive electronics cooling applications and were all found to provide adequate thermal performance up to approximately 30-50 W after which liquid entrainment compromised their performance.

  8. n Analise van die gemeente as deel van hierdie proses

    African Journals Online (AJOL)

    phase of this subject is the analysis of the situation in the local church. The purpose of the analysis is to syste matically ... planned carefully. This study gives attention to a plan ned situation-analysis of the local church. 1. ...... 6.1.2.5 Die dinkskrum en 'swot'-analise. 'n Dinkskrum is 'n tegniek waar 'n groep soveel as moontlik ...

  9. Study of integral characteristics and efficiency of a heat exchanger of thermosyphon type with finned tubes

    Directory of Open Access Journals (Sweden)

    Iliev Iliya K.

    2016-01-01

    Full Text Available The experimental research aims at the analysis of the thermal performance of a gas-liquid heat exchanger in a pilot plant. Results of the conducted experiment with a finned tubes thermosyphon heat exchanger using natural gas are presented. The installation was mounted at the exit of a flue gas from an existing steam generator “PK-4” with total power of 2.88 MW in the boiler room of Vini, Sliven, Bulgaria. Different experiments were carried out at different loads of the steam generator in order to determine the efficiency of the heat exchanger. Based on these results the coefficient of heat transfer of flue gas to the finned tubes was determined, based on different modes of operation with crossed and straight pipe bundles. The effectiveness-number of transfer units method was used.

  10. Experimental investigation on two-phase thermosyphon loop with partially liquid-filled downcomer

    International Nuclear Information System (INIS)

    Zhang, Penglei; Wang, Baolong; Shi, Wenxing; Li, Xianting

    2015-01-01

    Highlights: • A visual thermosyphon loop test bench is established. • Partially liquid-filled phenomenon in the downcomer is discovered. • The driving force may be smaller than the conventional prediction. • Liquid head in the downcomer is self-regulated by influencing factors. • Larger height difference does not always lead to better performance. - Abstract: Two-phase thermosyphon loops (TPTLs) are beginning to be extensively used in the field of air conditioning and heat recovery, where they have quite different flow characteristics compared with the traditional TPTLs used in cooling of electronics. However, in the existing studies, the flow features in the downcomer were ignored, and most researchers simply thought the downcomer was always full of liquid. In this study, a visual experimental setup was established, the flow features in the downcomer were observed and measured. And the influencing factors including temperature difference, liquid charge, height difference, and circulation flow resistance on the liquid head have been identified and investigated experimentally. The results show that, different from the conventional understandings, the downcomer can be partially liquid filled. At this time, the upper part of downcomer is a static saturation gas blockage, surrounded by a layer of liquid film, which does not provide the driving force. The liquid head in the downcomer, which provides the driving force, shows great self-regulation ability with different working conditions. Increasing the refrigerant charge, temperature difference, circulation flow resistance, and decreasing the height difference drives the liquid head to rise, and the downcomer tends to be fully liquid filled.

  11. Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

    International Nuclear Information System (INIS)

    Taherian, H.; Rezania, A.; Sadeghi, S.; Ganji, D.D.

    2011-01-01

    This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center of the absorber and center of the glass cover temperatures, were obtained. The simulation results were then compared with the experimental results in fall and showed a good agreement.

  12. Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen

    International Nuclear Information System (INIS)

    Piyush Sabharwall; Fred Gunnerson; Akira Tokuhiro; Vivek Utgiker; Kevan Weaver; Steven Sherman

    2007-01-01

    The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000 C) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900 C, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHE's) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger

  13. Validation of the generalized model of two-phase thermosyphon loop based on experimental measurements of volumetric flow rate

    Science.gov (United States)

    Bieliński, Henryk

    2016-09-01

    The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the lower vertical section and a condenser on the upper vertical section. The one-dimensional homogeneous and separated two-phase flow models were used in calculations. The latest minichannel heat transfer correlations available in literature were applied. A numerical analysis of the volumetric flow rate in the steady-state has been done. The experiment was conducted on a specially designed test apparatus. Ultrapure water was used as a working fluid. The results show that the theoretical predictions are in good agreement with the measured volumetric flow rate at steady-state.

  14. Experimental study of thermosyphons applied in bakery ovens; Estudo experimental do comportamento de termossifoes aplicado a fornos de coccao de paes

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Alexandre; Penteado, Ricardo Assis [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica]. E-mails: kupka@labsolar.ufsc.br; boto@labsolar.ufsc.br; Mantelli, Marcia B.H. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Matematica]. E-mail: marcia@labsolar.ufsc.br

    2000-07-01

    The present paper study thermosyphons applied to bakery ovens with special attention in the energy conservation and the quality of final baked product. A prototype simulating one internal section of a commercial oven was built for the experimental study. Stainless steel/water thermosyphons are installed vertically, close to the two lateral walls of this section The thermosyphons are very efficient heat exchangers and improves the temperature distribution inside the oven, saving energy and avoiding the product waste by under or overcooking. This research also intends to replace electric power and GLP by natural gas as the energy source, that is available in the South of Brazil, after the recent implantation of the Brazil/Bolivia gas line. The gas combustion happens in a separated chamber, so that, just the heated air are in contact with be bread in the cooking chamber. The final product has better quality and is free from the combustion residues. (author)

  15. Performance enhancement studies in a thermosyphon flat plate solar water heater with CuO nanofluid

    Directory of Open Access Journals (Sweden)

    Dasaien Anin Vincely

    2017-01-01

    Full Text Available Experiments were conducted on a thermosyphon type flat plate collector, inclined at 45°, for water heating application. Water and water based nanofluids were used as absorber fluid to gain heat from solar rays incident on the flat plate col-lector. Nanofluids were prepared by adding CuO nanoparticles of 40-50 nm size to the base fluid at 0.1, 0.2, 0.3, and 0.5 wt% (ζ. The hot absorber fluid was made to circulate in the shell side of a heat exchanger, placed at the top of the flat plate collector, where utility water was circulated inside a helically coiled Cu tube. Temperatures at strategic locations in the flat plate collector, working fluid, utility water inlet and outlet were measured. The nanofluid increases the collector efficiency with increasing ζ. A highest efficiency enhancement of 5.7% was observed for the nanofluid with ζ = 0.2 having a mass flow rate of 0.0033 kg/s. The 3-D, steady-state, conjugate heat transfer CFD analyses were carried out using the ANSYS FLUENT 15.0 software. Theoretically estimated buoyancy induced fluid flow rates were close with the CFD predictions and thus validates the computational methodology.

  16. Effect of nanofluid concentration on two-phase thermosyphon heat exchanger performance

    Directory of Open Access Journals (Sweden)

    Cieśliński Janusz T.

    2016-06-01

    Full Text Available An approach - relaying on application of nanofluid as a working fluid, to improve performance of the two-phase thermosyphon heat exchanger (TPTHEx has been proposed. The prototype heat exchanger consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. Distilled water and nanofluid water-Al2O3 solution were used as working fluids. Nanoparticles were tested at the concentration of 0.01% and 0.1% by weight. A modified Peclet equation and Wilson method were used to estimate the overall heat transfer coefficient of the tested TPTHEx. The obtained results indicate better performance of the TPTHEx with nanofluids as working fluid compared to distilled water, independent of nanoparticle concentration tested. However, increase in nanoparticle concentration results in overall heat transfer coefficient decrease of the TPTHEx examined. It has been observed that, independent of nanoparticle concentration tested, decrease in operating pressure results in evaporation heat transfer coefficient increase.

  17. Effect of nanofluid concentration on two-phase thermosyphon heat exchanger performance

    Science.gov (United States)

    Cieśliński, Janusz T.

    2016-06-01

    An approach - relaying on application of nanofluid as a working fluid, to improve performance of the two-phase thermosyphon heat exchanger (TPTHEx) has been proposed. The prototype heat exchanger consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. Distilled water and nanofluid water-Al2O3 solution were used as working fluids. Nanoparticles were tested at the concentration of 0.01% and 0.1% by weight. A modified Peclet equation and Wilson method were used to estimate the overall heat transfer coefficient of the tested TPTHEx. The obtained results indicate better performance of the TPTHEx with nanofluids as working fluid compared to distilled water, independent of nanoparticle concentration tested. However, increase in nanoparticle concentration results in overall heat transfer coefficient decrease of the TPTHEx examined. It has been observed that, independent of nanoparticle concentration tested, decrease in operating pressure results in evaporation heat transfer coefficient increase.

  18. Experimental study on the effect of fill ratio on an R744 two-phase thermosyphon loop

    International Nuclear Information System (INIS)

    Tong, Zhen; Liu, Xiao-Hua; Li, Zhen; Jiang, Yi

    2016-01-01

    Highlights: • Performance of R744 two-phase thermosyphon loop is experimentally analyzed. • There are usually some fluids that circulate in the loop without changing phase. • Maximum heat transfer ability is achieved at the fill ratio around 100%. • Lowest driving temperature difference is achieved at the fill ratio around 62%. • Thermosyphon loop with a lower fill ratio is more likely to fluctuate at small heat loads. - Abstract: As a natural, environmentally friendly fluid with excellent thermodynamic and transport properties, carbon dioxide is an effective alternative refrigerant. This paper describes an experiment conducted on an R744-based two-phase thermosyphon loop (TPTL). With different fill ratios of 45~151%, the effect of fill ratio on the working performance of the R744 TPTL is investigated. To maintain the conservation of momentum, part of the fluid circulates in the loop without changing phase; this part of the fluid may be liquid, vapor, or both liquid and vapor depending on the fill ratio. This is how the R744 TPTL self-adjusts among different heat loads. The experimental results show that the working state of the R744 TPTL has a lot to do with the fill ratio. With a low fill ratio, the TPTL is more likely to fluctuate under small heat loads. When the fill ratio is around 100%, the TPTL reaches its maximum heat transfer ability, and when the fill ratio is around 62%, the lowest driving temperature difference is achieved. Considering that the fill ratio's effect on the driving temperature difference is not very significant and that pursuing maximum heat transfer ability is more meaningful, a fill ratio of around 100% is recommended.

  19. Specification of a system for planning and analysis of independent generator connection impact on the electric distribution system; Especificacao de um sistema de planeamento e analise do impacto da conexao de geradores independentes no sistema electrico da distribuicao

    Energy Technology Data Exchange (ETDEWEB)

    Proenca, Luis Miguel; Matos, Manuel Antonio [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal); Campos, Manuel Luis Borges [Centro para a Excelencia na Distribuicao (CED), Sao Paulo, SP (Brazil)

    1999-07-01

    This paper describes a system for planning and analysis of the independent generator connection impact on the electric distribution system. This system is being developed under a contract signed between the Center for Excellency in the Distribution (CED), state of Sao Paulo - Brazil and the INESC, Porto - Portugal - energy unit.

  20. An environment integrated for identification, modeling, analysis, and control associated systems project to the power electric systems; Um ambiente integrado para identificacao, modelagem, analise e projeto de sistemas de controle associados a sistemas eletricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Luz, Lucas Thadeu Orihuela da

    1990-12-01

    An integrated environment which was developed to give support to the activities of identification, modeling, analysis and simulation of control systems of Electric Power Systems - EPS is presented. It is a computer program to be used in compatible IBM P C microcomputers. The program has two algorithms for systems identification: one for identification in the frequency domain and other to be used in the time domain. For the analysis, were implemented the algorithms of the frequency response and the root locus. One can simulate multivariable and nonlinear models. A set of auxiliary transformations is available to obtain the dynamic equation of the model declared for the simulation and to transform it in a transfer matrix. The hierarchical menus used for the selection of the program functions are presented and the dialogues and the others communication mechanisms with the user are described. The program in EPS's is demonstrated through the design of a Power System Stabilizer. The results obtained with the program are compared with the ones that were obtained in field tests. (author)

  1. An environment integrated for identification, modeling, analysis, and control associated systems project to the power electric systems; Um ambiente integrado para identificacao, modelagem, analise e projeto de sistemas de controle associados a sistemas eletricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Luz, Lucas Thadeu Orihuela da

    1990-12-01

    An integrated environment which was developed to give support to the activities of identification, modeling, analysis and simulation of control systems of Electric Power Systems - EPS is presented. It is a computer program to be used in compatible IBM P C microcomputers. The program has two algorithms for systems identification: one for identification in the frequency domain and other to be used in the time domain. For the analysis, were implemented the algorithms of the frequency response and the root locus. One can simulate multivariable and nonlinear models. A set of auxiliary transformations is available to obtain the dynamic equation of the model declared for the simulation and to transform it in a transfer matrix. The hierarchical menus used for the selection of the program functions are presented and the dialogues and the others communication mechanisms with the user are described. The program in EPS's is demonstrated through the design of a Power System Stabilizer. The results obtained with the program are compared with the ones that were obtained in field tests. (author)

  2. NEPHRUS: model of intelligent multilayers expert system for evaluation of the renal system based on scintigraphic images analysis; NEPRUS: modelo de sistema especialista em multicamadas inteligentes para avaliacao do sistema urinario baseado na analise de imagens cintilograficas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose W.E. da; Schirru, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Boasquevisque, Edson M. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear

    1997-10-01

    This work develops a prototype for the system model based on Artificial Intelligence devices able to perform functions related to scintigraphic image analysis of the urinary system. Criteria used by medical experts for analysis images obtained with {sup 99m} Tc+DTPA and/or {sup 99m} Tc+DMSA were modeled and a multi resolution diagnosis technique was implemented. Special attention was given to the programs user interface design. Human Factor Engineering techniques were considered so as to ally friendliness and robustness. Results obtained using Artificial Neural Networks for the qualitative image analysis and the knowledge model constructed shows the feasibility of Artificial Intelligence implementation that use `inherent` abilities of each technique in the resolution of diagnosis image analysis problems. (author). 12 refs., 2 figs., 2 tabs.

  3. Nephrus: expert system model in intelligent multilayers for evaluation of urinary system based on scintigraphic image analysis; Nephrus: modelo de sistema especialista em multicamadas inteligentes para avaliacao do sistema urinario baseado na analise de imagens cintilograficas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jorge Wagner Esteves da; Schirru, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear; Boasquevisque, Edson Mendes [Hospital dos Servidores do Estado, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear

    1999-11-01

    Renal function can be measured noninvasively with radionuclides in a extremely safe way compared to other diagnosis techniques. Nevertheless, due to the fact that radioactive materials are used in this procedure, it is necessary to maximize its benefits, therefore all efforts are justifiable in the development of data analysis support tools for this diagnosis modality. The objective of this work is to develop a prototype for a system model based on Artificial Intelligence devices able to perform functions related to cintilographic image analysis of the urinary system. Rules used by medical experts in the analysis of images obtained with {sup 99m} Tc+DTPA and /or {sup 99m} Tc+DMSA were modeled and a Neural Network diagnosis technique was implemented. Special attention was given for designing programs user-interface. Human Factor Engineering techniques were taking in account allowing friendliness and robustness. The image segmentation adopts a model based on Ideal ROIs, which represent the normal anatomic concept for urinary system organs. Results obtained using Artificial Neural Networks for qualitative image analysis and knowledge model constructed show the feasibility of Artificial Neural Networks for qualitative image analysis and knowledge model constructed show feasibility of Artificial Intelligence implementation that uses inherent abilities of each technique in the medical diagnosis image analysis. (author) 12 refs., 4 figs., 2 tabs.

  4. Experimental Study of a Thermosyphon Solar Water Heater Coupled to a Fibre-Reinforced Plastic (FRP) Storage Tank

    International Nuclear Information System (INIS)

    Nwosu, P. N.; Oparaku, O. U.; Okonkwo, W. I.; Unachukwu, G. O.; Agbiogwu, D.

    2011-01-01

    The thermal performance of the thermosyphon solar water heater was analyzed to show its applicability in a tropical climate using data of cloudy, sunny and hazy days. The average daily efficiency of the parallel-connected module, ranged between 35 and 40%. Also, an analysis of the temperature storage characteristics of a novel fibre-reinforced plastic (FRP) storage tank was undertaken. The inlet andoutlet positions were determined using the recommendation of Simon and Wenxian [1]: the optional position for the inlet/outlet was around the very top/bottom of the tank. The obtained results showed that the coupled FRP tank substantially retained and delivered the stored hot water during off-sunshine hours with minimal losses, and stratification occurred in the tank as a result. In view of the thermal performance, FRP materials can be efficiently employed in the design of solar hot water storage tanks. (authors)

  5. Heat-transfer enhancement of two-phase closed thermosyphon using a novel cross-flow condenser

    Science.gov (United States)

    Aghel, Babak; Rahimi, Masoud; Almasi, Saeed

    2017-03-01

    The present study reports the heat-transfer performance of a two-phase closed thermosyphon (TPCT) equipped with a novel condenser. Distillated water was used as working fluid, with a volumetric liquid filling ratio of 75 %. An increase in heat flux was used to measure the response of the TPCT, including variations in temperature distribution, thermal resistance, average temperature of each section of TPCT and overall thermal difference. Results show that for various power inputs from 71 to 960 W, the TPCT with the novel condenser had a lower wall-temperature difference between the evaporator and condenser sections than did the unmodified TPCT. Given the experimental data for heat-transfer performance, it was found that the thermal resistance in the TPCT equipped with the proposed condenser was between 10 and 17 % lower than in the one without.

  6. Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    This study focus on the analysis, modeling and simulation of solar domestic hot water(DHW) systems. Problems related to the system operation such as input weather data and hot water load conditions are also investigated.In order to investigate the heat loss as part of the total heat load, dynamic...... model of distribution network is developed and simulations are carried out for typical designed circulation type of distribution networks. For dynamic simulation of thermosyphon and drain-back solar DHW systems, thermosyphon loop model and drain-back tank model are put forward. Based on the simulations...

  7. Thermal performance of a closed advanced two-phase thermosyphon loop for cooling of radio base stations at different operating conditions

    International Nuclear Information System (INIS)

    Khodabandeh, Rahmatollah

    2004-01-01

    In this investigation an advanced thermosyphon loop with extended evaporator and condenser surfaces has been tested at high heat fluxes. The thermosyphon investigated is designed for the cooling of three parallel high heat flux electronic components. The tested evaporators were made from small blocks of copper in which five vertical channels with a diameter of 1.5 mm and length of 14.6 mm were drilled. The riser and downcomer connected the evaporators to the condenser, which is an air-cooled roll-bond type with a total surface area of 1.5 m 2 on the airside. Tests were done with Isobutane (R600a) at heat loads in the range of 10-90 W/cm 2 to each of the components with forced convection condenser cooling and with natural convection with heat loads of 10-70 W

  8. Cogeneration with gas turbine associated to the absorption refrigeration system: a computer program for exergy economics analysis; Cogeracao com turbina a gas associada ao sistema de refrigeracao por absorcao: um programa computacional para analise exergoeconomica

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Julio Santana [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Matematica] E-mail: santana@feg.unesp.br; Silveira, Jose Luz; Balestieri, Jose Antonio Perrella [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Energia

    2000-07-01

    This paper presents the development of a computer program for exergy and economic analysis of cogeneration systems applying gas turbine associated to the absorption refrigeration system. The computer program selects gas turbine systems viewing the operation under thermal parity through a data base composed by gas turbines commercially available in the market, under the ISO (International Standard Organization). The computer program corrects the system performance parameters selected for the installation local conditions. The exergy and economic analysis are made based on the lowest exergy manufacturing cost where the best system is considered. A case study of the computer program application is presented.

  9. Comparative analysis of three atmospheric dispersion coefficient systems at the Angra dos Reis, RJ, region; Analise comparativa de tres sistemas de coeficientes de dispersao atmosferica na regiao de Angra dos Reis, RJ

    Energy Technology Data Exchange (ETDEWEB)

    Biagio, Rosa Maria de Souza

    1982-07-01

    A comparative analysis was made in this work among Pasquill-Gifford (PG) atmospheric dispersion coefficients and those determined at the Juelich and Karlsruhe sites with the purpose of suggesting which one would be the most applicable to the Angra site. Each one of the three systems was determined by different experiments, carried out over sites with diversified features. The systems of Juelich and Karlsruhe were obtained over sites with high surface roughness and from stacks (elevated releases), while the PG system was obtained over sites with a small surface roughness and from ground level releases. The results of the application of these systems at a complex site like Angra,which has a highly diversified structure encompassing sea, vegetation, predominance of light winds and stable stability classes, show that the PG system, the most used in the world, is still the best choice. (author)

  10. Analysis of static safety of power systems: a study about contingencies selection criteria in the reactive subproblem; Analise de seguranca estatica de sistemas de potencia: um estudo sobre criterios de selecao de contingencias no subproblema reativo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Vicente Canto dos

    1993-12-01

    The main objective of static safety's analysis in power systems is the determination of the level of gravity of the different contingencies that can occur in a system. Habitually, static safety's analysis is divided in two parts: selection and analysis of contingencies. In this work, they are studied several criteria of selection of applicable contingencies to the sub-problem reactive and are introduced comparisons among results provided by different criteria. They are also studied several forms of evaluation of the impact caused by contingencies on the power systems reactive profile.

  11. Analysis of static safety of power systems: a study about contingencies selection criteria in the reactive subproblem; Analise de seguranca estatica de sistemas de potencia: um estudo sobre criterios de selecao de contingencias no subproblema reativo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Vicente Canto dos

    1993-12-01

    The main objective of static safety's analysis in power systems is the determination of the level of gravity of the different contingencies that can occur in a system. Habitually, static safety's analysis is divided in two parts: selection and analysis of contingencies. In this work, they are studied several criteria of selection of applicable contingencies to the sub-problem reactive and are introduced comparisons among results provided by different criteria. They are also studied several forms of evaluation of the impact caused by contingencies on the power systems reactive profile.

  12. Small disturbances stability analysis applied in a radial distribution system with distributed generation units; Analise de estabilidade a pequenos disturbios aplicada em um sistema de distribuicao radial com unidades de geracao distribuida

    Energy Technology Data Exchange (ETDEWEB)

    Dorca, Daniel Azevedo; Camacho, Jose Roberto [Universidade Federal de Uberlandia (UFU), MG (Brazil). Curso de Mestrado em Engenharia Eletrica

    2008-07-01

    This work investigates the small-disturbance stability of a 30 bus radial distribution system with distributed generation units. This work is realized through the time domain simulations and through the eigenvalue analysis and participation factors. The eigenvalue analysis show that is possible to predict a possible system instability face to a disturbance. The development of this work was stimulated by the increasing of the distributed generation units in the distribution networks. (author)

  13. Application of safety checklist to the analysis of the IEA-R1 reactor water retreatment system; Utilizacao do checklist de seguranca na analise do sistema de retratamento de agua do reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Maria Eugenia Lago Jacques; Sara Neto, Antonio Jorge; Lima, Toni Carlos Caboclo de; Ribeiro, Maria Alice Morato [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: melsauer@ipen.br

    2005-07-01

    In 1999, the management of the IEA-R1 Research Reactor (pool type - 5 MWth), located at IPEN/CNEN-SP, started the evaluation of the Reactor Pool Water Retreatment System to identify operational aspects, which could compromise the operators safety. The purpose was to identify and propose enhancements to the system which would be installed to substitute for the existing one. This process was conducted through a qualitative study of the system in operation. This study was carried out by a team composed of specialists in reactor operation, systems maintenance and radiological protection, and one safety analyst. The study consisted, basically, in local inspections to verify the physical and operational conditions of each equipment / component as well as aspects related to maintenance activities of the system. The process control and the operator procedures associated with the retreatment of the reactor pool water were also reviewed. The methodology adopted to develop the study was based in process hazard analysis technique named Safety Checklist. This paper presents a summary of this study and the main results obtained. Some operational and safety problems identified, the prevention and/or correction means to avoid them, and the recommendations and suggestions that have been implemented to the new design of the IEA-R1 Reactor Water Retreatment System, whose installation was concluded in 2003, are also presented. (author)

  14. Analysis of the influence of the expansion of the South American electric system in emissions of greenhouse gases; Analise da influencia da expansao do sistema eletrico Sul-Americano nas emissoes de gases de efeito estufa

    Energy Technology Data Exchange (ETDEWEB)

    Castagna, Annemarlen Gehrke [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Blesl, Markus [Institute of Economics and the Rational Use of Energie (IER), Stuttgart (Germany)

    2010-07-01

    South America combines economic and population growth with a consequent rapid increase in electricity demand. This can only be covered by building new power plants, use of the remaining renewable potential and expansion of transmission lines. The expansion of supply in all regions, with reliable generation and transmission systems is the greatest challenge for the continent in order to reduce social differences and not to curb economic development. To support the energy planning the application of system models represents useful method. This paper intends to analyze the expansion effect of power plant parks in regard of greenhouse gases emissions using a regionalized model system 'TIMES (The Integrated Markal - EFOM System)'. The model includes 10 South American countries (Argentina, Brazil, Bolivia, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay and Venezuela) with their respective power parks and transmission lines, demand divided in sectors, potential use of renewable energy sources, gas pipelines and possibilities of new interconnections within and between countries. As results are obtained the future installed capacity and generation according the energy use, greenhouse gases emissions, as well as the investments needed to expand the electric system in different scenarios. (author)

  15. Small nuclear power reactor emergency electric power supply system reliability comparative analysis; Analise da confiabilidade do sistema de suprimento de energia eletrica de emergencia de um reator nuclear de pequeno porte

    Energy Technology Data Exchange (ETDEWEB)

    Bonfietti, Gerson

    2003-07-01

    This work presents an analysis of the reliability of the emergency power supply system, of a small size nuclear power reactor. Three different configurations are investigated and their reliability analyzed. The fault tree method is used as the main tool of analysis. The work includes a bibliographic review of emergency diesel generator reliability and a discussion of the design requirements applicable to emergency electrical systems. The influence of common cause failure influences is considered using the beta factor model. The operator action is considered using human failure probabilities. A parametric analysis shows the strong dependence between the reactor safety and the loss of offsite electric power supply. It is also shown that common cause failures can be a major contributor to the system reliability. (author)

  16. A study of digital hardware architectures for nuclear reactors protection systems applications - reliability and safety analysis methods; Um estudo de arquiteturas de hardware para aplicacao em sistemas digitais de protecao de reatores nucleares - metodos de analise de confiabilidade e seguranca

    Energy Technology Data Exchange (ETDEWEB)

    Benko, Pedro Luiz

    1997-07-01

    A study of digital hardware architectures, including experience in many countries, topologies and solutions to interface circuits for protection systems of nuclear reactors is presented. Methods for developing digital systems architectures based on fault tolerant and safety requirements is proposed. Directives for assessing such conditions are suggested. Techniques and the most common tools employed in reliability, safety evaluation and modeling of hardware architectures is also presented. Markov chain modeling is used to evaluate the reliability of redundant architectures. In order to estimate software quality, several mechanisms to be used in design, specification, and validation and verification (V and V) procedures are suggested. A digital protection system architecture has been analyzed as a case study. (author)

  17. Analysis of the technical impact of decentralized independent production based on cogeneration, in public distribution systems; Analise do impacto tecnico da producao independente descentralizada baseada em cogeracao em redes de distribuicao de servico publico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose L. Pereira da; Lopes, J.A. Pecas [Universidade do Porto (Portugal). Faculdade de Engenharia; Pascoal, Jose A.F. [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal)

    1999-07-01

    This paper describes the methodology adopted and the results obtained in the evaluation of the impact of decentralized independent production plants based on cogeneration in the distribution system of Portugal Public Service. The analysis concerns with impact on a medium voltage network where the significant integration of these units occurs. The methodology involved the definition of various exploration scenarios, specifically the recent regulations related to the reactive energy to be supplied to the network, during peak and full hours, by the independent production. This work also presents the global results of impact no the system, considering voltage profiles, branching congestion and network losses.

  18. Cogeneration in breweries analysis and simulation of systems for simultaneous generation of power, heat and refrigeration using natural gas; Sistemas de refrigeracao a partir da cogeracao: analise e simulacao de propostas para o caso de cervejarias utilizando gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, Antonio Garrido

    1998-07-01

    The present work analyses some proposals of cogeneration systems for the simultaneous generation of power, heat and refrigeration in a brewery. The requirements of steam, refrigeration and electricity, as well as the production of beer in a plant of the Antarctica Company, located in Jaguariuna - SP were collected monthly for the year of 1997. Three conceptions of systems using two gas turbines with heat recovery steam generator were then proposed to meet the surveyed demand. The proposals differ in the refrigeration system: the first one uses a traditional ammonia compression system while the second uses an ammonia absorption system, the third proposal is a combination of the compression and absorption systems. These proposals are compared to the present configuration which purchases electricity from the Public Utility for power and refrigeration (using an ammonia compression)system, and fuel oil to generate steam for process heat. The technical, economical and environmental feasibility of the proposals, as well as of the present configuration are discussed on the basis of mass balances, energy balances (first law of Thermodynamics), exergy fluxes (second law analysis), operational and capital cost, based on simulation of the performance of each configuration proposed to meet the monthly electricity, steam and refrigeration requirements for the referred plant. The turbines were chosen so as to meet the peek energy demand of the plant and two cases were simulated for each proposal: turbine operational meets only the demand of the plant and turbine operates at full load, selling electricity for the Public utility. Results obtained show that the current operational costs are higher than any of the proposals presented. The high capital costs of the proposals, though,make them less interesting financially. The simulation of the case of excess electricity to the Public Utility is very attractive, considering the cost of natural gas 3,38 U$/M btu and the fare of 40 U

  19. Analysis of energy performance in two systems of cogeneration used in plants of sugar cane; Analise de desempenho energetico em dois sistemas de cogeracao empregados em usinas de cana de acucar

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Felipe A.A.; Rosa, Rodrigo A. [Cogeracao Sistemas de Energia Ltda., Recife, PE (Brazil)

    2004-07-01

    One of the options to overcome the current volatility in Brazil's power consumption outlook relates to the employment of other sources for power generation, namely solar energy, wind power or the use of biomass, namely the power generation through the cane bagasse. One should realize, however, that the economic accomplishment for launching a generation system should depend on the level of effectiveness of all processes and/or equipment comprising the system thereof. As far as the sugar-alcohol industry is concerned, the larger the system effectiveness is, the bigger the surplus of bagasse becomes and, hence, the better the chance of achieving financial earnings. Two generation systems shall be evaluated, aiming to thermo-dynamically identify the differences between the use of small equipment-driven turbines (like choppers, shredders and mills) and multi-stage turbo-generators, in order to replace the electric-powered drive units. Therefore, one shall follow thermodynamic-based criteria, namely the steam specific consumption, the equipment availability and effectiveness, thus allowing a comparison for each engine. Such survey shows that the effectiveness reaches nearly 68% for the turbo-generators and 43% for the small turbines. Under the economic perspective, one can find a saving of 89.500 tonnes per crop of bagasse, standing for an additional turnover of US$ 895.000,00 annually. (author)

  20. Analysis of the potential use of palm oil biodiesel for power generation in Amazonian remote systems; Analise do potencial do biodiesel de dende para geracao eletrica em sistemas isolados da Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Anamelia Medeiros

    2008-07-01

    This paper aims to analyze the potential of palm-oil biodiesel production and consumption in remote Amazonian systems (not connected to the national grid), taking into account economic, social and environmental impacts of this biofuel alternative. Through a detailed analysis of remote systems and in particular the examination of the national subside called 'Combustible Consumption Account', the study presents potential scenarios of biodiesel demand for electricity generation in the region, considering also the generation and grid connections projects in forthcoming years. Definition of current and future quantities of biodiesel needed to maintain thermal production in this system defines the Biodiesel investment necessities in remote Amazonian states (Acre, Amapa, Amazonas, Para, Rondonia, Roraima). Possibility of using biodiesel made progress with the launch of the National Program of Production and Use of Biodiesel (PNPB) in 2004. Although African Palm-oil trees adapt very well Amazonian soil, wide adoption of this specie as raw material for biodiesel production shows some barriers, like raise of palm oil price in global market, palm tree long maturation time and attractive price for conventional diesel in the region. Even if using palmoil biodiesel result in obvious significant social and environmental benefits, these benefits tend not to compensate the inefficiency of the market and, thus, expand the biofuel production in the Northern Region. (author)

  1. Qualitative analysis of the maintenance politics of the systems of a typical PWR by artificial neural networks; Analise qualitativa da politica de manutencoes dos sistemas de um PWR tipico por redes neurais artificiais

    Energy Technology Data Exchange (ETDEWEB)

    Lourenco, Victor Hugo Moreno

    2010-02-15

    Proceedings and techniques in order to maximize the reliability and the availability of industrial plants have been used along the last decades by specialists and professionals of maintenance. However, the modem industrial systems' sizing, and the increasing complexity and interdependence among its components have become this activity's planning a more and more difficult task. Considering this scenario, the objective of the present work is to provide a computational tool which is able to help about the taking decision's task, and about planning policies of maintenance practiced in thermonuclear plants. The tool developed is based on the artificial neural networks (ANN) for the recognition of standards and establishment of correlations among events occurred in the components of pressurized water reactor (PWR) typical systems. The ANN work as miners of database of failure events, and are able to identify connections and to establish imperceptible inferences even for the most experienced specialists in maintenance of nuclear systems. The results were attained from realistic data and are confronted against the maintenance's classic policies which are practiced nowadays on PWR thermonuclear plants. These results show the solidity of the technique in valuing and predicting failures in a real power plant, and is able to be used as a tool for supporting decisions about planning maintenance policies on a typical PWR. (author)

  2. Analysis of the potential use of palm oil biodiesel for power generation in Amazonian remote systems; Analise do potencial do biodiesel de dende para geracao eletrica em sistemas isolados da Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Anamelia Medeiros

    2008-07-01

    This paper aims to analyze the potential of palm-oil biodiesel production and consumption in remote Amazonian systems (not connected to the national grid), taking into account economic, social and environmental impacts of this biofuel alternative. Through a detailed analysis of remote systems and in particular the examination of the national subside called 'Combustible Consumption Account', the study presents potential scenarios of biodiesel demand for electricity generation in the region, considering also the generation and grid connections projects in forthcoming years. Definition of current and future quantities of biodiesel needed to maintain thermal production in this system defines the Biodiesel investment necessities in remote Amazonian states (Acre, Amapa, Amazonas, Para, Rondonia, Roraima). Possibility of using biodiesel made progress with the launch of the National Program of Production and Use of Biodiesel (PNPB) in 2004. Although African Palm-oil trees adapt very well Amazonian soil, wide adoption of this specie as raw material for biodiesel production shows some barriers, like raise of palm oil price in global market, palm tree long maturation time and attractive price for conventional diesel in the region. Even if using palmoil biodiesel result in obvious significant social and environmental benefits, these benefits tend not to compensate the inefficiency of the market and, thus, expand the biofuel production in the Northern Region. (author)

  3. Analysis of the internal temperature of the combustion chamber of a compact system of co-generation; Analise das temperaturas internas da camara de combustao de um sistema compacto de co-geracao

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Joao B.F. [Universidade de Fortaleza (UNIFOR), CE (Brazil)], email: furlan@unifor.br; Couto, Heraldo S. [Instituto Nacional de Pesquisas Espaciais (INPE), Cachoeira Paulista, SP (Brazil)], email: heraldo@lcp.inpe.br; Holanda, Carlos A.M. de [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Metalurgica e de Materiais], email: almir@metalmat.ufc.br

    2008-07-01

    Nowadays, the energy deficit represents one of the biggest governmental challenges, since there is still a great number of communities living in areas without electricity energy; and thus without access to electro-electronic equipment such as television, refrigerators, computers. The main focus of this work is to present the possibility of electricity energy generation in conjunction with the frozen or hot water production in for places without electricity transmission nets or even any type of alternative power plants. The system is based on the standard air cycle called Brayton cycle composed of a turbo-compressor model 4LGZ from BorgWarner, a combustion chamber, a power turbine, a heat exchanger, a water-ammonia chiller, a 5.0 kV A generator, and a command panel for automation and distribution of energy. This system that uses natural gas or LPG, will supply electric energy from the generator, hot water from the heat exchange with the gases of combustion, and water frozen from chiller using as the hot source the gases proceeding from the power system. The prototype is already being tested and the first results obtained are excellent. In this paper, we analyze the internal combustion chamber temperatures. (author)

  4. Use of the sensitivity analysis for multi-attributes decision models for oil exploration and production systems; Uso da analise de sensibilidade em modelos de decisao multiatributos para sistemas de exploracao e producao de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Ricardo

    2000-07-01

    Today, oil companies must be able to survive in a hostile and competitive environment. Such environment involves volatility of oil prices, the narrow margins of profitability, and ever increasing environmental restrictions. In order to survive, firms must have the appropriate tools to consider the tradeoffs involving the financial, environmental, technological and of market parameters which are the key elements within the investment decision-making process. The aim of the present work is to analyze the behavior of the weights (relative importance) of the attributes int the multi-criteria decision model through a high dimension sensitivity analysis. Among the benefits of such method are: provide the analyst (decision-maker) with a better characterization and control of the weights of the attributes, providing the user with a clear view of the entire decision process. The methodology suggested in this dissertation was applied in two oil exploration and production case studies. The first case involved the selection of an exploratory target among three options. In this case, there is interaction of the objectives of the company, where financial, technological and of market parameters interact. In the second case, a hypothetical production project is suggested. For this second study, the decision-maker has the option of using one of the following production systems: a FPSO (Floating, Production, Storage and Offloading); a TLP (Tension Leg Platform); or a SS (Semi Submersible). The attributes for each one of the production systems are financial, technological and environmental. In this second case, the model makes it possible to simulate several options, providing the manager with the choice of the most appropriate production system to this objectives and preferences. (author)

  5. Energy analysis of physic nut (Jatropha curcas L.) culture in dry land system: case study; Analise energetica da cultura de pinhao-manso (Jatropha curcas L.) em sistema de sequeiro: estudo de caso

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, Michelle Sato [Universidade Estadual Paulista Julio de Mesquisa Filho (UNESP), Botucatu, SP (Brazil). Faculdade de Ciencias Agrarias. Pos-Graduacao em Agronomia], e-mail: msfrigo@fca.unesp.br; Bueno, Osmar de Carvalho; Esperancini, Maura Seiko Tsutsui [Universidade Estadual Paulista Julio de Mesquisa Filho (UNESP), Botucatu, SP (Brazil). Faculdade de Ciencias Agrarias. Dept. de Gestao e Tecnologia Agroindustrial], e-mails: osmar@fca.unesp.br; maura@fca.unesp.br

    2008-07-01

    Due to the gradual reduction of the oil reserves, alternatives come being studied and one of these are bio fuel being one of the potential cultures for its production would be the physic nut (Jatropha curcas L.). However, studies concerning this culture are scarce in international and national level, as much in what it says respect to how much energy the agronomic questions. The present work aimed to evaluate the index of energy efficiency for unit of area of agroecosystem physic nut under dry land system, in determined system. It was used primary data from NNE Minas Agro-Florestal Ltda., located at Janauba/MG, harvest season 2004/2005, therefore these are the oldest areas in production of the country oldest. In the construction of the structure of energy great expenses of agroecosystem in question, the gotten average values had been considered, inside of the studied areas of dry land. The results of the energy efficiency had been presented by the structure of energy great expenses, for type, source and form and for the rude energy. A rude energy of the equal product was observed the 319,30 MJ. ha-1, with a participation of 12,09% and 87,91% of the energies direct and indirect, respectively. It was concluded that agro ecosystem studied depended basically on industrial power plant, under the form of insecticides (39,71%). The energy balance was of 319.30 MJ. ha -1, the same value of the systems, because the non usage of recycled sources, being that due the same the factor the index of energy efficiency, was not possible of being calculated; with regard to cultural efficiency this was of 0.25. (author)

  6. Feasibility analysis of installing a natural gas cogeneration system in a slaughterhouse; Analise da viabilidade da implantacao de um sistema de cogeracao de energia a gas natural em um frigorifico

    Energy Technology Data Exchange (ETDEWEB)

    Takaki, Alessandro Tomio; Dib, Fernando Henrique; Campitelli, Flavio Moreti; Romao Junior, Ricardo Agudo; Ramos, Ricardo Alan Verdu [Universidade Estadual Paulista (NUPLEN/UNESP), Ilha Solteira, SP (Brazil). Dept. de Engenharia Mecanica. Nucleo de Planejamento Energetico, Geracao e Cogeracao de Energia], Email: nuplen@dem.feis.unesp.br

    2006-07-01

    In this work the analysis of the viability of implantation of a natural gas cogeneration system in a bovine slaughterhouse is carried out. Among the studied configurations there are the current plant and the modified plant that allow the use of natural gas. For evaluation of the performance, energetic and exegetic analyses for each one of the configurations are carried out. It's also accomplished a thermo economic analysis that makes possible to evaluate the reflexes of the investment and combustible on the composition of the cost of products. (author)

  7. Energy analysis in a swine production system with use of manure as bio fertilizer in pasture; Analise energetica em sistema de producao de suinos com aproveitamento dos dejetos como biofertilizante em pastagem

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Cassio V. [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil)], email: agro.cassio@hotmail.com; Campos, Alessandro T. [Universidade Federal de Lavras (DEG/UFLA), MG (Brazil). Dept. de Engenharia], email: campos@deg.ufla.br; Bueno, Osmar C [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas; Silva, Enilson B [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Dept. de Agronomia

    2009-07-01

    This work objective was to esteem the amount of energy employed in a complete cycle swine production and the energy balance of the system with utilization of the generated manure as bio fertilizer in pasture area, by using five cycles' average data, in a commercial farm in Diamantina municipal district - MG Brazil. The energy coefficient of each involved component was quantified in the productive process of finished swine, residues treatment and Brachiaria decumbens pasture production, in the form of ration, human labor, electric power, machines and equipment, fuel and lubricants, buildings, finished swine production and Brachiaria decumbens production. The average quantity of energy to produce 1 kg of alive swine was of 53.35 MJ. Of total employed energy in the system 76.03% (1,067,106.07 MJ) refers to the inputs and 23.97% (331,400 MJ) refers to the outputs, resulting in an energy efficiency coefficient of 0.31. The energy converted in swine for abate corresponded to 55.58% (184,200 MJ) of the outputs, while the pasture of Brachiaria decumbens reached a value of 44.42% (147,200 MJ). (author)

  8. The feasibility analysis for the merger of powder from steel making dedusting system in red ceramic; Analise da viabilidade da incorporacao do po de despoeiramento siderurgico em ceramica vermelha

    Energy Technology Data Exchange (ETDEWEB)

    Santos, D.M.S.; Goncalves, S.S.; Mocbel, E.B.B.; Barbosa, A.C.C.; Leal, A.P.S.; Lopes, S.A.; Feitosa, E.F.; Silva, G.S.; Rabelo, A.A.; Fagury Neto, E., E-mail: danilo.marciano@gmail.com, E-mail: fagury@unifesspa.edu.br [Universidade Federal do Sul e Sudeste do Para (UNIFESSPA), Maraba, PA (Brazil). Instituto de Geociencias e Engenharias

    2016-07-01

    The aim of this work was to study the variation of physical and mechanical properties of ceramics made from two clays with the addition of dedusting system powder from a local steel making plant (SDP), which was added in proportions of 3%, 5 %, 7 % and 10 %. The test-bodies were shaped by uniaxial two-stage pressing, calcined for 2 hours at 300 °C and sintered at temperatures of 900 °C, 1000 °C and 1100 °C. The analyzed properties were apparent density, water absorption, apparent porosity, linear firing shrinkage, flexural strength and plasticity index. The starting materials were characterized by XRF as well, in order to evaluate the chemical composition. This methodology showed good results in the development of future work related to the area. (author)

  9. Risk analysis and management of pipeline systems - the TRANSPETRO's experience in Sao Paulo and Brazil's Mid-West; Analise e gerenciamento de riscos de sistemas de dutos - a experiencia da TRANSPETRO em Sao Paulo e no Centro Oeste

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Carlos Alberto Rodrigues; Yogui, Regiane Tiemi Teruya [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    Risk Analysis is an important instrument on risk management and emergency control. TRANSPETRO has a long pipeline network to transport oil and by-products in Sao Paulo State and Brazil Midwest. The beginning of the elaboration of Risk Analysis in TRANSPETRO was in 1987 and extended continually until 2000. Since 2001, with the Excellence Program on Environmental and Operational Safety Management, a review of Risk Analysis has been done on all pipeline's system. This work presents the experience acquired, the main difficulties, the solutions adopted, the results about individual and social risks, the main risk management actions and the evolution of the studies during the last fifteen years pointing out the technical development of the TRANSPETRO, the environment agency and the consultant companies. (author)

  10. Use of GIS (Geographic Information Systems) and analysis of demand: an analysis for predictions in the energy segment; O emprego do SIG (Sistema de Informacoes Geograficas) e a analise de demanda: um ensaio para previsoes no segmento de energia

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Jorge Henrique de [Petroleo Brasileiro SA. (PETROBRAS), Rio de Janeiro, RJ (Brazil). Unidade de Gas e Energia

    2008-07-01

    The energy assumed a preponderant paper to the current societies because it became the number spine of both economic and social activities developed. Technological advances and the economic and social development of the nations, was based on the transformation and use of natural resources in products and services. Such transformation if gave more of accented form from the Industrial Revolution where the substitution of activities until then carried through by the man, for the job of machines, transformed the way of life and the behavior of the society. Particularly the projection of demand of energy send to the following duality: the problem should be evaluated in a wide way, in other words, considering the whole range of component variables of the decision process for generation and allocation of the energy supply; however, in a local way regarding with the search of models that optimize of the energy potentials and the consequent search of value added market. Historically the forecast of the energy demand uses the GDP mainly. It is presupposed that the association of such variables to the areas that these act, or polygons that delimit them, it happens in a homogeneous way and that the limits of such areas constitute an identified change of behavior. However, this premise is false, because such polygons are defined for operational and / or politician criteria not having warranty that such distributions are really homogeneous. As solution, the development and use of decision support systems based on GIS (Geographic Information System) technology has been along the last years a powerful modeling and simulation tool. The objective of this paper is to introduce the application of techniques of spatial analysis in the activity of projection, activity that is inherent to the forecast energy demand, to mitigate the future developments of scientific models and applications associates. (author)

  11. Three-dimensional radiotherapy planning system for esophageal tumors: comparison of treatment techniques and analysis of probability of complications; Planejamento tridimensional para radioterapia de tumores de esofago: comparacao de tecnicas de tratamento e analise de probabilidade de complicacoes

    Energy Technology Data Exchange (ETDEWEB)

    Justino, Pitagoras Baskara; Carvalho, Heloisa de Andrade; Ferauche, Debora; Ros, Renato [Sao Paulo Uni., SP (Brazil). Hospital das Clinicas. Instituto de Radioterapia (InRad)]. E-mail: pitagorasb@hotmail.com

    2003-06-01

    Radiotherapy techniques for esophageal cancer were compared using a three-dimensional planning system. We studied the following treatment techniques used for a patient with squamous cell carcinoma of the middle third of the esophagus: two antero-posterior and two latero-lateral parallel opposed fields, three fields ('Y' and 'T'), and four fields ('X'). Dose-volume histograms were obtained considering spinal cord and lungs as organs at risk. Analysis was performed comparing doses in these organs as recommended by the Normal Tissue Complication Probability (NTCP) and Tumor Control Probability (TCP). When only the lungs were considered the best technique was two antero-posterior parallel opposed fields. The spinal cord was best protected using latero-lateral fields. We suggest the combination of at least two treatment techniques: antero-posterior fields with 'Y' or 'T' techniques, or latero-lateral fields in order to balance the doses in the lungs and the spinal cord. Another option may be the use of any of the three-field techniques during the whole treatment. (author)

  12. Analysis of the feasibility of solar heating systems composite for packaging recyclable for use in rural low income; Analise da viabilidade economica de sistemas de aquecedores solares compostos por embalagens reciclaveis para utilizacao em comunidades rurais de baixa renda

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel Filho, Luis Roberto Almeida; Maiochi, Tamara; Pereira, Danilo F.; Magalhaes, Marcelo M. de [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Tupa, SP (Brazil)], email: gabrielfilho@tupa.unesp.br; Cremasco, Camila P. [Faculdade de Tecnologia (FATEC), Presidente Prudente, SP (Brazil); Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Dept. de Bioestatistica

    2011-07-01

    Solar heaters are an appropriate technology for tropical and sub tropical to warm bath water through the energy in sunlight. The development of conventional solar heaters is in the market and its acceptance is still low due to high cost. However, low-cost solar heaters have been developed in recent years to meet a consumer demand that currently do not have access to this technology, especially low-income rural communities. The aim of this study was to analyze the economic feasibility of solar water heaters built with recyclable materials (plastic bottles and milk cartons) through the consequent reduction of sales of electricity. For development work, a heater was built with recyclable materials in accordance with the manuals provided by the Department of the Environment of Parana (SEMA) and found time to use electric showers by families of rural properties in order to determine the costs and billing of electricity. By spending on materials, we concluded that the system was feasible, with amortization over 13 months in fixed installments of R$ 23.79. (author)

  13. Thermographic and spectrophotometric analysis of the extrinsic tooth bleaching using a diode laser and a LED system. In vitro; Analise termografica e espectrofotometrica do clareamento dental extrinsico utilizando laser de diodo e sistema de LED. Estudio In vitro

    Energy Technology Data Exchange (ETDEWEB)

    Micheli, Paola Racy de

    2004-07-01

    The aim of this study was to evaluate the intra-pulpal temperature change, as well as to compare the bleaching power of a 38% hydrogen peroxide (Opalescence Xtra Boost- Ultradent. Inc), when activated with a diode laser, with a LED system and without activation, in the extrinsic tooth bleaching in vitro. Ten mandibular human incisors, a thermocouple, 45 bovine incisors and a spectrophotometer (Shade Eye- Shofu) for the color analysis. The samples were divided into 3 groups: 38% hydrogen peroxide activated by a diode laser (ZAP lasers, wavelength 808 nm {+-} 5, power of 1,4 W); 38% hydrogen peroxide activated by LED (Bright LEC-Mmoptics, wavelength 470 nm {+-} 25, power of 380 mW); 38% hydrogen peroxide without activation. After the artificial pigmentation, the bleaching agent acted for the same time in the 3 groups, differing only by the type of activation. The results of temperature showed that the LED activation was safer than the diode laser, which, in some measures exceeded the limit of 5.6 deg C. The luminosity of the samples did not show significantly statistics differences in none of the groups and moments of this study. The diode laser and LED activation did not influenced at the bleaching power of the peroxide, which showed effective for removing stains, with great capacity of bleaching bovine tooth artificially darkened. (author)

  14. Analysis of fracturing in the basalts of the Serra Geral Aquifer and the potential regional recharge of the Guarani Aquifer System; Analise de fraturas dos basaltos do Aquifero Serra Geral e o potencial de recarga regional do Sistema Aquifero Guarani

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, A. J.; Assis Negri, F. de; Azevedo Sobrino, J. M.; Varnier, C.

    2012-11-01

    The Geological Institute, belonging to the Ministry for the Environment of the State of Sao Paulo, is currently undertaking regional research into vertical groundwater flow through the basalts in the Serra Geral Aquifer (ASG), which influences recharge of the sandstones in the underlying Guarani Aquifer System (SAG) and therefore the quantity of groundwater available and its susceptibility to pollution. The study area corresponds to the outcropping region of the ASG, an area of the state of Sao Paulo that contains important urban centres. The methods used included: (1) field work, focused on characterizing the vertical tectonic structures and the stresses responsible for their origin; and (2) an analysis of the structural data collected, aimed at identifying brittle tectonic events and their influence on groundwater flow. Distinguishing between cooling and tectonic fractures is a relevant aspect of the field work as only the tectonic events are capable of cutting across the vesicular beds, which otherwise form a barrier against vertical flow and block any connection between the aquifers. Three tectonic strike-slip events have been identified, each having generated hybrid tectonic fractures, which, because they involve extension as well as shearing, potentially favour flow. Diagnostic features suggest the occurrence in the south-western zone of the study area of preferential flow along fractures in the direction N70-80W and N60-80E, and secondary ones trending N20W and N20E; in the northeastern zone there is flow along secondary fractures in the direction N15W and N5-10E and in the central zone N40-65W. (Author)

  15. A basic study on Thermosyphon-type thermal storage unit (TSU) using Nanofluid as the heat transfer medium

    Science.gov (United States)

    Li, Shuang-Fei; Wang, Ping-Yang; Liu, Zhen-hua

    2017-11-01

    This study proposed a novel thermosyphon-type thermal storage unit using water-based CuO nanofluid as the phase-change heat transfer medium. Seven tubular canisters containing solid-liquid phase-change material (PCM) with peak melting temperature of 100 °C were placed vertically into the center of the TSU which is a vertical cylindrical vessel made of stainless steel. Coat formed by depositing nanoparticles during the phase-change process was adopted to increase the wettability of the heat transfer surfaces of the canisters. We investigated the phase-change heat transfer, as well as the heat-storage and heat-release properties, of the TSU through experimental and computational analysis. Our results demonstrate that this thermal storage unit construction can propose good heat transfer and heat-storage/heat-release performance. The coating of nanoparticles onto the heat transfer surfaces increases the surface wettability and improves both the evaporation and condensation heat transfer. The main thermal resistance in the TSU results from the conductive heat transfer inside of the PCM. All phase-change thermal resistance of liquid film in charging and discharging processes can be ignored in this TSU.

  16. Novel thermosyphon driven hydrothermal flow-through cell for in situ and time resolved neutron diffraction studies

    International Nuclear Information System (INIS)

    Xia, Fang; Qian, Gujie; Etschmann, Barbara; University of Adelaide, South Australia, Australia; University of Adelaide, South Australia, Australia; Studer, Andrew; Olsen, Scott

    2009-01-01

    Full text: A flow-through cell for hydrothermal phase transformation studies by in situ and time-resolved neutron diffraction has been designed and constructed. The cell has a large internal volume of 320 m L and can work at up to 300 degree Centigrade under autogeneous vapour pressures (-85 bar). The fluid flow is driven by thermosyphon which is realized by the proper design of temperature difference around the closed loop[1,2). The main body of the cell is made of stainless steel (316 type), but the sample compartment is constructed from non-scattering Ti/Zr alloy. We have successfully commissioned the cell on Australia's new high intensity powder diffractometer WOMBAT in ANSTO, using a simple transformation reaction from leucite (KAISi 2 O 6 ) to analcime (NaAISi 2 O 6H2O ) and then back from analcime to leucite. The demonstration proved that the cell is an excellent tool for probing hydrothermal phase transformations. By collecting diffraction data every 5 min, it was clearly seen that leucite was progressively transformed to analcime in a NaCI solution, and the produced analcime was progressively transformed back to leucite in a K 2 CO 3 solution.

  17. A basic study on Thermosyphon-type thermal storage unit (TSU) using Nanofluid as the heat transfer medium

    Science.gov (United States)

    Li, Shuang-Fei; Wang, Ping-Yang; Liu, Zhen-hua

    2018-05-01

    This study proposed a novel thermosyphon-type thermal storage unit using water-based CuO nanofluid as the phase-change heat transfer medium. Seven tubular canisters containing solid-liquid phase-change material (PCM) with peak melting temperature of 100 °C were placed vertically into the center of the TSU which is a vertical cylindrical vessel made of stainless steel. Coat formed by depositing nanoparticles during the phase-change process was adopted to increase the wettability of the heat transfer surfaces of the canisters. We investigated the phase-change heat transfer, as well as the heat-storage and heat-release properties, of the TSU through experimental and computational analysis. Our results demonstrate that this thermal storage unit construction can propose good heat transfer and heat-storage/heat-release performance. The coating of nanoparticles onto the heat transfer surfaces increases the surface wettability and improves both the evaporation and condensation heat transfer. The main thermal resistance in the TSU results from the conductive heat transfer inside of the PCM. All phase-change thermal resistance of liquid film in charging and discharging processes can be ignored in this TSU.

  18. Investigation of a heat storage for a solar heating system for combined space heating and domestic hot water supply for homeowner´s association "Bakken"

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1998-01-01

    A heat storage for a solar heating system for combined space heating and domestic hot water supply was tested in a laboratory test facility.The heat storage consist of a mantle tank with water for the heating system and of a hot water tank, which by means of thermosyphoning is heated by the water...

  19. Stability analysis of single-phase thermosyphon loops by finite difference numerical methods

    International Nuclear Information System (INIS)

    Ambrosini, W.

    1998-01-01

    In this paper, examples of the application of finite difference numerical methods in the analysis of stability of single-phase natural circulation loops are reported. The problem is here addressed for its relevance for thermal-hydraulic system code applications, in the aim to point out the effect of truncation error on stability prediction. The methodology adopted for analysing in a systematic way the effect of various finite difference discretization can be considered the numerical analogue of the usual techniques adopted for PDE stability analysis. Three different single-phase loop configurations are considered involving various kinds of boundary conditions. In one of these cases, an original dimensionless form of the governing equations is proposed, adopting the Reynolds number as a flow variable. This allows for an appropriate consideration of transition between laminar and turbulent regimes, which is not possible with other dimensionless forms, thus enlarging the field of validity of model assumptions. (author). 14 refs., 8 figs

  20. Predicting Flow Reversals in a Computational Fluid Dynamics Simulated Thermosyphon Using Data Assimilation.

    Science.gov (United States)

    Reagan, Andrew J; Dubief, Yves; Dodds, Peter Sheridan; Danforth, Christopher M

    2016-01-01

    A thermal convection loop is a annular chamber filled with water, heated on the bottom half and cooled on the top half. With sufficiently large forcing of heat, the direction of fluid flow in the loop oscillates chaotically, dynamics analogous to the Earth's weather. As is the case for state-of-the-art weather models, we only observe the statistics over a small region of state space, making prediction difficult. To overcome this challenge, data assimilation (DA) methods, and specifically ensemble methods, use the computational model itself to estimate the uncertainty of the model to optimally combine these observations into an initial condition for predicting the future state. Here, we build and verify four distinct DA methods, and then, we perform a twin model experiment with the computational fluid dynamics simulation of the loop using the Ensemble Transform Kalman Filter (ETKF) to assimilate observations and predict flow reversals. We show that using adaptively shaped localized covariance outperforms static localized covariance with the ETKF, and allows for the use of less observations in predicting flow reversals. We also show that a Dynamic Mode Decomposition (DMD) of the temperature and velocity fields recovers the low dimensional system underlying reversals, finding specific modes which together are predictive of reversal direction.

  1. Predicting Flow Reversals in a Computational Fluid Dynamics Simulated Thermosyphon Using Data Assimilation.

    Directory of Open Access Journals (Sweden)

    Andrew J Reagan

    Full Text Available A thermal convection loop is a annular chamber filled with water, heated on the bottom half and cooled on the top half. With sufficiently large forcing of heat, the direction of fluid flow in the loop oscillates chaotically, dynamics analogous to the Earth's weather. As is the case for state-of-the-art weather models, we only observe the statistics over a small region of state space, making prediction difficult. To overcome this challenge, data assimilation (DA methods, and specifically ensemble methods, use the computational model itself to estimate the uncertainty of the model to optimally combine these observations into an initial condition for predicting the future state. Here, we build and verify four distinct DA methods, and then, we perform a twin model experiment with the computational fluid dynamics simulation of the loop using the Ensemble Transform Kalman Filter (ETKF to assimilate observations and predict flow reversals. We show that using adaptively shaped localized covariance outperforms static localized covariance with the ETKF, and allows for the use of less observations in predicting flow reversals. We also show that a Dynamic Mode Decomposition (DMD of the temperature and velocity fields recovers the low dimensional system underlying reversals, finding specific modes which together are predictive of reversal direction.

  2. Banking system and financial monitoring in Russian Federation

    Directory of Open Access Journals (Sweden)

    Osipov A.V.

    2017-04-01

    Full Text Available the article explores the definition of banking system and financial monitoring. Attention is emphasizes on role of internal control in aspect their relation to contraction to money laundering and financing of terrorism/ Internal control is analises from the point of view law, economic and management. Basic attention in the article author emphasizes on work of systems of financial monitoring in organizations.

  3. Development of a YouTube videos feelings analiser = Desarrollo de un analizador de sentimientos de videos de Youtube

    OpenAIRE

    Valle Salas, José Miguel del

    2018-01-01

    Nowadays, Youtube is one of the most successful social networks, therefore it has more and more impact in our society. Due to this it's quite useful to know the sentiments that this platform videos produces. This project has been focused in the development of a tool able to analise this sentiments, which could be used for di�erent purposes like Market studies or emotional learning for people who has some functional diversity. The technologies used during the project development has b...

  4. Thermohydraulic modeling of the dry air passive containment cooling system process in the Westinghouse AP-600 ALWR

    Energy Technology Data Exchange (ETDEWEB)

    Harari, R; Weis, Y; Barnea, Y [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev

    1996-12-01

    Following postulated events of a LOCA, the passive Containment Cooling System (PCCS) uses dry air to transfer the residual heat by natural circulation. The air flow path, designed between the steel reactor containment hot shell and the concrete shield building, creates an open thermosyphon. The purpose of this inherently safe process is to assure the long term steady-state cooling of the nuclear core after an emergency shutdown (authors).

  5. Semi-empiric model of an air cooled cabinet air conditioner for the dynamic analysis of the building and acclimation systems integrated behaviour; Modelo semi-empirico de condicionador de gabinete resfriado a ar para analise dinamica do comportamento integrado de edificacoes e sistemas de climatizacao

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Jorge E. [Para Univ., Belem (Brazil). Dept. de Engenharia Mecanica]. E-mail: jecorrea@amazon.com.br; Melo, Claudio. E-mail: melo@nrva.ufsc.br; Negrao, Cezar O. R. E-mail: negrao@energia.damec.cefetpr.br

    2000-07-01

    This work presents a semi-empirical model for a air cooled case air conditioner. This model is to be inserted in the EPS-r program (Environmental System Performance - research version) allowing the dynamic analysis of the integrated behaviour of buildings and acclimation systems using this equipment. Results obtained from simulations under the operation conditions existing in Brazil are analysed.

  6. Passive cooling systems in power reactors

    International Nuclear Information System (INIS)

    Aharon, J.; Harrari, R.; Weiss, Y.; Barnea, Y.; Katz, M.; Szanto, M.

    1996-01-01

    This paper reviews several R and D activities associated with the subject of passive cooling systems, conducted by the N.R.C.Negev thermohydraulic group. A short introduction considering different types of thermosyphons and their applications is followed by a detailed description of the experimental work, its results and conclusions. An ongoing research project is focused on the evaluation of the external dry air passive containment cooling system (PCCS) in the AP-600 (Westinghouse advanced pressurized water reactor). In this context some preliminary theoretical results and planned experimental research are for the fature described

  7. Comparative analysis of photovoltaic electric power storage systems by using batteries and hydrogen, at remote communities of the Amazon region; Analise comparativa de sistemas de armazenamento de energia eletrica fotovoltaica por meio de baterias e hidrogenio, em localidades isoladas da regiao Amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, Andre Luis [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica; Neves Junior, Newton Pimenta [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Lab. de Hidrogenio]. E-mail: andrelf@fem.unicamp.br

    2008-07-01

    In this work, comparative analyses of photovoltaic power storage were made, first by the traditional means employing lead-acid batteries, and second by means of electrolytic hydrogen which was later reconverted to power in a fuel cell. In order to design the two systems, it was used a load profile of the communities in Amazon region and by means of a mathematical model, implemented in a spreadsheet, that considers the several devices and their efficiencies in order to make it possible to specify the system components. The results were employed to evaluate the economic viability of the two systems in remote communities. Considering the present conditions, it was verified that the battery system is slightly advantageous. However, it was also observed that a minor cost reduction of the electrolizers/buffer/fuel cell would make the hydrogen system very competitive, becoming the best option for photovoltaic power storage. (author)

  8. Thermal analysis and phase diagrams of the LiF BiF{sub 3} e NaF BiF{sub 3} systems; Analise termica e diagramas de fase dos sistemas LiF-BiF{sub 3} e NaF-BiF{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Gerson Hiroshi de Godoy

    2013-07-01

    Investigations of the binary systems LiF-BiF{sub 3} and NaF-BiF{sub 3} were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF{sub 3}) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF{sub 3} to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF{sub 3} were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF{sub 4}, decomposes into LiF and a liquid phase. The NaF-BiF{sub 3} system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF{sub 3}) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF{sub 4} was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF{sub 4}, NaBiF{sub 4} and a solid solution of NaF and BiF{sub 3} called {sup I.} The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

  9. Analysis of normative requirements for the development and implementation of a quality management system in Brazilian nuclear installations and activities; Analise de requisitos normativos para o desenvolvimento e a implementacao de um sistema de gestao da qualidade em instalacoes e atividades nucleares brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Kibrit, Eduardo

    2008-07-01

    The present work identifies, characterizes and analyses the normative requirements for the development and implementation of quality management systems in Brazilian nuclear installations and activities. The requirements established in standards IAEA GS-R-3, IAEA GS-G-3.1, IAEA DS 349, NBR ISO 9001:2000 e CNEN-NN-1.16 are critically analyzed. A correlation matrix of the applicable standards is presented and the related topics among them are identified. The standards IAEA GS-R-3, IAEA GS-G-3.1 and IAEA DS 349 define general requirements for establishing, implementing, assessing and continually improving an integrated management system in nuclear installations and activities, in IAEA member countries. The standard NBR ISO 9001:2000 establishes general requirements for the implementation of a quality management system in all kinds of organizations. The standard CNEN NN-1.16 establishes the regulating requirements for the quality assurance systems and programs of nuclear installations, for licensing and authorization for operation of these installations in Brazil. The standard IAEA GS-R-3 that replaces the code IAEA 50-C-Q introduces the concept of 'Integrated Management System' for the nuclear area, in preference to the concepts of 'Quality Assurance' and 'Quality Management'. This new approach is aligned with the current tendency incorporating requirements of quality, safety, health, environment, security, economics and other in a unique management system. Examples of quality management systems implemented by Brazilian nuclear organizations and by nuclear organizations outside Brazil are analyzed and considered in the discussion of results. (author)

  10. Analysis of normative requirements for the development and implementation of a quality management system in Brazilian nuclear installations and activities; Analise de requisitos normativos para o desenvolvimento e a implementacao de um sistema de gestao da qualidade em instalacoes e atividades nucleares brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Kibrit, Eduardo

    2008-07-01

    The present work identifies, characterizes and analyses the normative requirements for the development and implementation of quality management systems in Brazilian nuclear installations and activities. The requirements established in standards IAEA GS-R-3, IAEA GS-G-3.1, IAEA DS 349, NBR ISO 9001:2000 e CNEN-NN-1.16 are critically analyzed. A correlation matrix of the applicable standards is presented and the related topics among them are identified. The standards IAEA GS-R-3, IAEA GS-G-3.1 and IAEA DS 349 define general requirements for establishing, implementing, assessing and continually improving an integrated management system in nuclear installations and activities, in IAEA member countries. The standard NBR ISO 9001:2000 establishes general requirements for the implementation of a quality management system in all kinds of organizations. The standard CNEN NN-1.16 establishes the regulating requirements for the quality assurance systems and programs of nuclear installations, for licensing and authorization for operation of these installations in Brazil. The standard IAEA GS-R-3 that replaces the code IAEA 50-C-Q introduces the concept of 'Integrated Management System' for the nuclear area, in preference to the concepts of 'Quality Assurance' and 'Quality Management'. This new approach is aligned with the current tendency incorporating requirements of quality, safety, health, environment, security, economics and other in a unique management system. Examples of quality management systems implemented by Brazilian nuclear organizations and by nuclear organizations outside Brazil are analyzed and considered in the discussion of results. (author)

  11. Analysis of rationality and efficiency of electricity utilization in posture poultry companies by computation platform based in fuzzy system; Analise da racionalidade e eficiencia da utilizacao de energia eletrica em empresas de avicultura de postura via plataforma computacional baseada em sistema fuzzy

    Energy Technology Data Exchange (ETDEWEB)

    Cremasco, Camila Pires [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Dept. de Bioestatistica; Faculdade de Tecnologia (FATEC), Presidente Prudente, SP (Brazil); Gabriel Filho, Luis Roberto Almeida [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Tupa, SP (Brazil). Fac. de Ciencias Agronomicas; Viais Neto, Daniel dos Santos; Bordin, Deyver [Faculdade de Tecnologia (FATEC), Presidente Prudente, SP (Brazil); Silva, Helenice de Oliveira Florentino [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Dept. de Bioestatistica], E-mails: gabrielfilho@tupa.unesp.br., dvneto@fatecpp.edu.br, bordin@yahoo.com.br, helenice@ibb.unesp.br

    2012-11-01

    A great application of intelligent systems is in control of the electric power consumption of enterprises. For the assessment of the way that the company uses the electricity there are two indices which are called load factor and power factor. To facilitate the assessment of the performance of electric power consumption by the companies it is interesting that there is a single index indicating globally as energy is being used by the same. The goal of this work was to develop a software to assist laying poultry companies in the region of Bastos in more rational and efficient use of electric energy. For this, a system has been developed called Fuzzy Energy integrated environment developed with Delphi 2010. For the determination of fuzzy factor (situation of the company), we used a fuzzy system prepared in advance. The data collected over a period of 3 years helped the system programming. The software was able to present the situation of the company studied in a manner accessible to the user, and their results were tested accuracy 100 according to fuzzy system. With the inference method of Mandani, unable to create a general simulation of all relevant points of enterprise data. (author)

  12. Pilot fluidized bed combustor system applied to thermal energy production from light hydrocarbons - part I: description and hydrodynamics analysis; Sistema combustor piloto a leito fluidizado para producao de energia termica a partir de hidrocarbonetos leves. Parte I: descricao e analise hidrodinamica do sistema

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Leandro P. de; Souza Junior, Francisco de Assis; Alves, Stella M.A.; Estevao, Paulo [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lucena, Sergio; Souza, Phillipi R. de O. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Lab. de Controle e Otimizacao de Processos; Santos, Douglas A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2008-07-01

    During the last years, the employment of light hydrocarbons in combustion systems for power generation has been announced by Brazilian Government's like a great bet for diversification the energetic matrix in spite of the provisional crisis. As consequence, high demand and growing R and D investments caused immediate reflexes in all economical and industrial sectors of the Natural Gas chain, mainly considering the gas from Campos, Santos and Espirito Santo offshore fields offered to the market. Regarding this, Northeast Region of Brazil shows itself to be attentive to the energy market tendencies and to environmental sector, creating conditions for developing new technologies and applications for the gas consumption. Among the possible applications of the gas consumption, the fluidized bed combustion systems are highlighted, like a real alternative for energy applying of the hydrocarbons produced, considering a good safety range to effective environmental demands. Thereby, the present work aimed to perform the description of a pilot fluidized bed combustor system with sand using light hydrocarbons - specifically, natural gas and LPG. Thereby, said pilot fluidized bed combustor operates isothermically without developing flames and/or hot spots. Besides the exposed, a hydrodynamic analysis of the system was made, identifying variables and parameters onto fluidized bed combustion process. (author.

  13. Comparative analysis between two systems to generate electric energy for isolated community in the interior of the Amazon state: fuel cells with natural gas reformer versus diesel generation; Analise comparativa entre dois sistemas de geracao de energia eletrica para a comunidade isolada no interior do estado do Amazonas: celula a combustivel com reformador para gas natural versus gerador diesel

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Paula Duarte; Bergamini, Cristiane Peres; Camargo, Joao Carlos; Lopes, Daniel Gabriel [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica; Esteves, Gheisa Roberta Telles [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo de Pesquisas e Estudos Ambientais; Silva, Ennio Peres da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin

    2004-07-01

    Although great part of the domestic territory is already supplied with electric energy, still there are many regions where the system is precarious or nonexistent, generically called isolated communities. In the majority of the cases these communities are supplied with Diesel oil generators and the substitution of this fuel for available alternative energy in the localities has been object of study of some institutions of research spread throughout the country. Currently, the use of fuel cells has been strongly argued in the generation of electric energy associated with the local energy necessity, from the use of a regional fuel and this is due to the high efficiency of allied energy conversion to the low ambient impacts that this equipment offers. Most of the different types of fuel cells use hydrogen as a fuel to produce electricity, and it is extracted from renewable or non-renewable sources of energy. Then, the article has the objective of comparing in first analysis the energy efficiency and the cost between the two systems: the ones used currently in the great majority of the isolated communities, constituted of a Diesel engine-generator system, with Natural Gas Reformer System/ Purifier of Hydrogen/ Fuel Cell/ and to analyze if such project presents characteristics that qualifies it to get the carbon credits proposed in the Mechanism of Clean Development. (author)

  14. Erosion and sediment deposition evaluation on slopes under different tillage systems in the Cerrado region using the {sup 137}Cs fallout technique; Analise da distribuicao do fallout do {sup 137}Cs na avaliacao da erosao e deposicao de sedimentos em sistemas de manejo de solo sob Cerrado

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Robson Clayton Jacques

    2010-07-01

    In Brazil, the expansion of agricultural areas causes several problems on natural resources. With the increasing occupation of the Cerrado region by agriculture, a series of environmental problems like deforestation, soil erosion and soil compaction are appearing and causing radical transformations in the natural landscape due to removing almost all native vegetation. The conventional tillage system (CTS) is considered an inadequate form of soil management for its frequently irremediable consequences of soil compaction and soil erosion, and the no till system (NTS) makes the maintenance of the soil conditions possible, letting them close to the natural environment, thus reducing rates of soil erosion. The objective of this work was to evaluate the efficiency of riparian forests in the retention of sediments originated for three different tillage systems, through the fallout {sup 137}CS redistribution technique, the Universal Soil Loss Equation (USLE) and some physical and chemical parameters that indicate the structural conditions of the soils of Goiatuba and Jandaia-GO. In the three areas, soil profiles were collected in three layers of 20 cm (0-20, 20-40 and 40-60 cm) at distinct points located along linear transects in the direction of the maximum slope until the riparian forest. In the riparian forest of each area, trenches were opened and soil was sampled to evaluate the activity of {sup 137}Cs and the physical and chemical parameters of soil. Detection of the activity of {sup 137}Cs was made with a gamma ray detector model (GEM-20180P, EG and ORTEC) connected to a multichannel analyzer. The comparison of averages was made using the Tukey test at 5% level of significance. The. results indicated that, the three soil tillage systems presented high rates of soil erosion and deposition of sediments and the riparian forest of the areas under CTS, NTS and pasture, located downstream received great amounts of sediments, and that only the riparian forest of CTS was

  15. Analysis and proposals of regulatory issues aimed at reducing emissions of greenhouse gases in the thermoelectric generation of isolated systems; Analise e propostas de aspectos regulatorios visando a reducao de emissoes de gases de efeito estufa na geracao termoeletrica dos sistemas isolados

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Pedro Coelho de Souza Monteiro [Universidade Salvador (UNIFACS), BA (Brazil)

    2008-07-01

    Restricted access to electricity, the existence of an energy matrix based on fossil fueled electricity plants and the lack of financial means by the population living in the Northern region of Brazil to afford the costs with electricity generation, transmission and distribution in the region created the need to implement cross subsidies in the country's electric sector isolated system. The subsidy policies have aimed at allowing the access to electricity for the population and industries in the north of Brazil and at promoting the economic development of this region, but have brought a great cost to society, particularly the Fuel Consumption Account (CCC), considering the environmental impacts of the fossil fuel use. This paper evaluates the current structure and the regulatory norms of the electricity sector's subsidies granted to the Isolated Systems, and intend to propose measures to reduce emissions of greenhouse gases in the thermoelectric generation plants in the isolated systems with the implementation of governmental incentives to power plants efficiency. (author)

  16. Analysis of the changes in the consumption profile of the system use gas in Bolivia-Brazil Gas Pipeline after integration with the Campinas-Rio Gas Pipeline; Analise das alteracoes do perfil de consumo de gas de sistema no Gasoduto Bolivia-Brasil apos a interligacao deste gasoduto com o Campinas-Rio

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Almir Beserra dos; Bisaggio, Helio da Cunha; Veloso, Luciano de Gusmao [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The natural gas pipeline transport is carried out by one or more compression stations. Each station possesses one or more compressors. The compressor's fuel is usually natural gas itself. The amount of natural gas consumed by the compressors fluctuates daily according to the demand at the city-gates. The daily operational result of a pipeline is known as imbalance. The imbalance is the difference between the natural gas entering into a in a pipeline and the volume delivered in the city-gates added to system use gas. The imbalance analyses in a pipeline that uses natural gas powered compressors requires the analyses of the system use gas. The aim of this work is to study the system use gas in the Bolivia-Brazil pipeline using the available data from the Superintendencia de Comercializacao e Movimentacao de Petroleo, seus Derivados e Gas Natural - ANP and compare the change of the volume consumed before and after the entry into operation of the Campinas-Rio gas pipeline. (author)

  17. Comparative analysis of the heat transfer rates in constant (CAV) and variable (VAV) volumes type multi zone acclimation system operating in hot and humid climate; Analise comparativa das taxas transferencia de calor em sistemas de climatizacao do tipo volume de ar constante (CAV) e volume de ar variavel (VAV) multizona operando em clima quente e umido

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Cesar A.G.; Correa, Jorge E. [Para Univ., Belem (Brazil). Centro Tecnologico. Dept. de Engenharia Mecanica]. E-mails: gsantos@ufpa.br; jecorrea@amazon.com.br

    2000-07-01

    This work performs a comparative analysis among the constant and variable air volume multi zones acclimation systems, used for provide the thermal comfort in buildings. The work used the simulation HVAC2KIT computer program. The results of sensible and latent heats transfer rates on the cooling and dehumidification, inflating fan capacity, and heat transfer on the final heating condenser were obtained and analysed for the climate conditions of the Brazilian city of Belem from Para State, presenting hot and humid climate during all the year.

  18. Qualitative and quantitative analysis of the infrared system in patients' positioning by comparison between two methods for tracking isocenters; Analise qualitativa e quantitativa do sistema de infravermelho do Exac Trac X-ray 6D no posicionamento de pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.T. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina; Nakandakari, M.V.N.; Sales, C.P.; Cunha, A.P.V.; Sereno, M.; Rodrigues, L.N., E-mail: camila_fmedica@hotmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Instituto de Radiologia. Servico de Radioterapia

    2014-12-15

    With the advent of techniques for treatment of high complexity, such as radiosurgery and stereotactic radiotherapy, there is an increased need to reduce spatial uncertainties due to the delivery of high doses per fraction. In this work the accuracy of the Infrared (IR) system BrainLab version 5.5 was evaluated from through the positioning of patients with cranial diseases, and then followed by the routinely implementation at the Hospital das Clinicas da Faculdade de Medicina da USP (HCFMUSP). The validation tests were performed by making use of an isocenter phantom from BrainLab which first evaluated the uncertainty due to the positioning and then its repeatability. Further analysis provided by measurements of 60 patients has been made performed and compared with an IR and localization's box for stereotactic coordinates. The greatest variations in all the tests and all the degrees of freedom can be considered less than 1.0 mm and 0.1 °, translational and rotational respectively, thus ensuring the accuracy of positioning system of patients required in techniques of high complexity. (author)

  19. Economic and financial analysis of hybrid solar-wind power generation system installed in a isolated community in Jalapao-Tocantins, Brazil; Analise economica-financeira do sistema de geracao de energia eletrica hibrido solar-eolico instalado em uma comunidade isolada no Jalapao-TO

    Energy Technology Data Exchange (ETDEWEB)

    Santos, W.F.; Zukowski Junior, J.C.; Nobrega, S.L. de; Marcon, R.O. [Universidade Luterana do Brasil (CEULP/ULBRA), Palmas, TO (Brazil). Centro Universitario Luterano de Palmas. Curso de Engenharia Agricola], Emails: zukowski@uft.edu.br, olavo@ulbra-to.br, silvestre@ulbra-to.br

    2009-07-01

    With the increasing of energetic demand in several production sectors, the search for renewable energy sources which do not cause negative environmental impacts has become more and more relevant. Amongst all the important factors to decide for installing isolated generation systems as renewable sources or diesel and taking the distribution network to isolated communities, it should be considered the economic viability of those benefits. This study aimed to analyse the hybrid solar wind system installed in an isolated community, in Jalapao - TO. Three scenarios were analyzed: first of them, getting the capital back with MRI = 6% per year; second one, getting the capital back with MRI = 0; and third, without getting the investment back. In all the three cases, O and M costs were considered. The proceeds were calculated from the production at the communities workshop, in which the electricity was available. The results indicated that this technology is economically viable if the generated energy is used for production process. It also demonstrated that the third scenario is more interesting for the community, since the contribution per family is only 8% of its incomes. (author)

  20. Analysis of economic viability in a hybrid solar-wind system in the generation of electrical energy to an Maroon isolated community of Jalapao - TO, Brazil; Analise da viabilidade economica em um sistema hibrido solar-eolico na geracao de energia eletrica para uma comunidade isolada e quilombola do Jalapao - TO

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Weder Ferreira dos; Zukowski Junior, Joel Carlos; Nobrega, Silvestre Lopes da; Marcon, Rogerio Olavo [Universidade Luterana do Brasil (CEULP/ULBRA), Palmas, TO (Brazil). Centro Universitario Luterano

    2008-07-01

    With the increasing of energetic demand in several production sectors, the search for renewable energy sources which do not cause negative environmental impacts has become more and more relevant. Amongst all the important factors to decide for installing isolated generation systems as renewable sources or diesel and taking the distribution network to isolated communities, it should be considered the economic viability of those benefits. This study aimed to analyse the hybrid solar-aeolian system installed in an isolated community, in Jalapao/TO. Three scenarios were analyzed: first of them, getting the capital back with MRI = 6% per year; second one, getting the capital back with MRI = 0; and third, without getting the investment back. In all the three cases, O and M costs were considered. The proceeds were calculated from the production at the community workshop, in which the electricity was available. The results indicated that this technology is economically viable if the generated energy is used for production process. It also demonstrated that the third scenario is more interesting for the community, since the contribution per family is only 8% of its incomes. (author)

  1. Risk analysis and management of pipeline systems - the TRANSPETRO's experience in Sao Paulo and Brazil's Mid-West; Analise e gerenciamento de riscos de sistemas de dutos - a experiencia da TRANSPETRO em Sao Paulo e no Centro Oeste

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Carlos Alberto Rodrigues; Yogui, Regiane Tiemi Teruya [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    Risk Analysis is an important instrument on risk management and emergency control. TRANSPETRO has a long pipeline network to transport oil and by-products in Sao Paulo State and Brazil Midwest. The beginning of the elaboration of Risk Analysis in TRANSPETRO was in 1987 and extended continually until 2000. Since 2001, with the Excellence Program on Environmental and Operational Safety Management, a review of Risk Analysis has been done on all pipeline's system. This work presents the experience acquired, the main difficulties, the solutions adopted, the results about individual and social risks, the main risk management actions and the evolution of the studies during the last fifteen years pointing out the technical development of the TRANSPETRO, the environment agency and the consultant companies. (author)

  2. Comparative analysis of high pressure sodium vapor lamps and mercury vapor lamp with the solid state (LED) in the public lighting systems; Analise comparativa das lampadas de vapor de sodio a alta pressao e de vapor de mercurio com a lampada a estado solido (LED) em sistemas de iluminacao publica

    Energy Technology Data Exchange (ETDEWEB)

    Damato, J.C.; Bueno, J.E.; Astorga, O.A.M. [Universidade Estadual Paulista (LESIP/UNESP), Guaratingueta, SP (Brazil). Lab. de Eficiencia Energetica em Sistemas de Iluminacao Publica; Ricciulli, D.L.S. [Universidade Estadual Paulista (DEE/UNESP), Guaratingueta, SP (Brazil). Dept. de Engenharia Eletrica

    2009-07-01

    The necessity of energy conservation in Brazilian electric sector, with the intention to diminish the resources of generation investments, has going to use of electric energy conservation programs, being most important PROCEL - a national program of electric conservation energy by ELETROBRAS, and inside this, a national program for public illumination and efficient traffic signaling - named 'Reluz'. This program looks for a more efficient implantation of public lighting systems, that requires the use of lamp technologies that present a greater value in a relation between lumen/watt relation and then beyond providing economy, due to low consumption of electric energy. Besides technologies that are appearing, the inclusion of LED lamps, which offers a great application potential, comes blunting as improvement alternative, being that the next public illumination parks will be able count on these lamps associates to the high-pressure sodium lamps and other types currently used. (author)

  3. Critical analysis of the management of waste system originated at the uranium mining and processing. A case study of the Concentrated Unit of Uranium - INB; Analise critica do sistema de gerenciamento de rejeitos provenientes de mineracao e beneficiamento de uranio. Um estudo de caso da Unidade de Concentrado de Uranio/INB

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Valeska Peres de

    2005-07-01

    The uranium world market faced a depreciation of this commodity during the last decades. Recently, decreases in the secondary supply (represented by highly enriched uranium - HEU - stocks detained by the former Soviet Union) turned out the market dependent upon primary supply again. In order to cope with this changing demands and market conditions, new uranium mining/milling projects must start operation, or at least, former uranium production plants must be improved. Environmental questions have been and certainly will continue to be a determinant factor concerning the operational feasibility of these facilities. Mining/milling activities have the potential to cause risks to the human health and to the environment. In case of uranium projects, radiological impacts shall also be taken into consideration. Amongst the most relevant environmental aspects associated with the operation of a uranium project, generated wastes are usually of major concern and deserve appropriate management strategies. As a result the objective of the present work was to examine the waste management system of the Brazilian uranium production unity located at the municipality of Caetite, northeast region of the country. An open pit mine and a milling facility compose this unit. The extraction method employed is acid heap leach (using H{sub 2}SO{sub 4}). It could be assessed that the overall conceptual management strategy is in agreement with the practices adopted worldwide. Atmospheric impacts, caused by the emissions of radon and aerosols must be investigated in more details. Mathematical simulation revealed that no significant impact in groundwater is expected due to mobilization and transport of radionuclides from the milling wastes. However, the impacts of drainage water, accumulated in the open pit, into groundwater cannot be discarded yet. Screening techniques were applied to assess the potential contribution of the leached ore piles as a {sup 226}Ra source of pollution. Our results

  4. A geographic information system and multi criteria analysis method for site selection of spent nuclear fuel disposal; Metodologia baseada em sistemas de informacao geografica e analise multicriterio para a selecao de areas para a construcao de um repositorio para o combustivel nuclear usado

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Vivian Borges

    2009-07-01

    This thesis aims to develop a site selection methodology for the construction of final repository for the spent nuclear fuel disposal, by using geographic information systems (GIS) and multi-criteria decision analysis. Decision making processes of this kind are often complex, given the great number of space parameters to consider and also the typically conflicting opinions of the diverse stake holders. By using GIS, data from different space parameters can be quickly and reliably stored, treated and analyzed. Multi-criteria techniques allow for the incorporation of different stake holders' opinions. These tools, when jointly used, allow for the decision process to be more transparent, quick and reliable. The method developed was applied to the particular case of the state of Rio de Janeiro. Weights obtained from an expert panel and also by using the Hierarchical Analysis Method and cartographic data were combined in the GIS. The application showed that it is possible not only to select and classify areas as to their aptness for the proposed objective, but also to exclude those clearly inadequate areas, thus optimizing the selection process by reducing the search space and consequently minimizing costs and the time spent in the search. (author)

  5. A comparative analysis of reliability, maintainability and availability for two alternatives of the production submarine systems: ANM and submarine ducts versus BOP and a subsea well testing tree; Analise comparativa da confiabilidade, mantenabilidade e disponibilidade para duas alternativas de sistemas submarino de producao: ANM e dutos submarinos versus BOP e arvore submarina de teste

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Arlindo Antonio de; Polillo Filho, Adolfo; Santos, Otto Luiz Alcantara [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This technical article presents a study using the concepts of the Engineering of the Reliability and Risk Analysis with the objective of doing a comparative evaluation of the reliability of two alternative production systems for a marine well: one composed by a wet christmas tree (ANM) producing through underwater ducts (flow lines) and other, usually used in tests of long duration, using a subsea BOP and a subsea well testing tree (AST). The central point of the work was the evaluation of the probability of happening an event considered as critic, denominated 'critical flaw', during the well production life. The work uses one of the procedures and methodologies adopted in the Well Construction Engineering, GERISK, together with four computer applications for data treatment, generation of flaw distribution curves and times of repair, modelling and Monte Carlo simulations. The adopted strategy was the one of starting from the existent report, to assume an interval for the possible real value of the relevant parameters and then to establish the scenarios (more probable, optimist and pessimist). Based on those sceneries, the considered premises, the modelling and the reliabilities obtained for each one of the variables, the simulations have been made. As results, are presented the medium readiness, MTTFF (Mean Time To First Failure), the number of flaws and the expected costs. The work also displays the sensibility analysis in respect to the time of production of the well. (author)

  6. Microstructural analysis of metal solution interfacial films in the multiphase brine CO{sub 2}, H{sub 2}S hydrocarbon inhibitor system; Analise microestrutural de filmes na interface metal-solucao no sistema multifasico salmoura Co{sub 2}/H{sub 2}S hidrocarboneto inibidor

    Energy Technology Data Exchange (ETDEWEB)

    Forero, Adriana; Yesid Pena, Dario [Universidad Industrial de Santander, Bucaramanga (Colombia); Bott, Ivani de S. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Ciencia dos Materiais e Metalurgia

    2005-07-01

    This work presents an analysis of the formation of different films obtained at the metal - solution interface in a multiphase Brine - CO{sub /}H{sub 2}S Hydrocarbon - Inhibitor - Steel AISI SAE 1020 system. Tests were carried out on loss of mass test pieces in a static autoclave, for exposure times of 21 days. Infrared Absorption Spectroscopy (IAS), X Ray Diffraction (XRD) and Scanning Electronic Microscopy (SEM) techniques, were used for the analysis of the products of corrosion and the inhibitor films formed. The results obtained for XRD indicate the formation hydrous oxide of iron, Siderite, Magnetite, and in some cases chloride crystals and iron sulphates. The results obtained by SEM, show that the thin films of the inhibitor and corrosion products have irregular surfaces, are porous, fragile and have little adhesion to the metal. Additionally the generation of primary films of carbonate of iron saturated with carbon and oxide of iron was confirmed and also the formation of secondary carbonates of iron due to recrystallization of the of iron carbonate. (author)

  7. A comparative analysis of reliability, maintainability and availability for two alternatives of the production submarine systems: ANM and submarine ducts versus BOP and a subsea well testing tree; Analise comparativa da confiabilidade, mantenabilidade e disponibilidade para duas alternativas de sistemas submarino de producao: ANM e dutos submarinos versus BOP e arvore submarina de teste

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Arlindo Antonio de; Polillo Filho, Adolfo; Santos, Otto Luiz Alcantara [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This technical article presents a study using the concepts of the Engineering of the Reliability and Risk Analysis with the objective of doing a comparative evaluation of the reliability of two alternative production systems for a marine well: one composed by a wet christmas tree (ANM) producing through underwater ducts (flow lines) and other, usually used in tests of long duration, using a subsea BOP and a subsea well testing tree (AST). The central point of the work was the evaluation of the probability of happening an event considered as critic, denominated 'critical flaw', during the well production life. The work uses one of the procedures and methodologies adopted in the Well Construction Engineering, GERISK, together with four computer applications for data treatment, generation of flaw distribution curves and times of repair, modelling and Monte Carlo simulations. The adopted strategy was the one of starting from the existent report, to assume an interval for the possible real value of the relevant parameters and then to establish the scenarios (more probable, optimist and pessimist). Based on those sceneries, the considered premises, the modelling and the reliabilities obtained for each one of the variables, the simulations have been made. As results, are presented the medium readiness, MTTFF (Mean Time To First Failure), the number of flaws and the expected costs. The work also displays the sensibility analysis in respect to the time of production of the well. (author)

  8. Analysis of technical feasibility, economic and environmental operation of the lift system Tiete-Billings in the supply of water and electricity in the metropolitan region of Sao Paulo; Analise da viabilidade tecnico-economico-ambiental da operacao do sistema elevatorio Tiete-Billings no suprimento de agua e eletricidade na regiao metropolitana de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Luiz

    2010-07-01

    This study examines the characteristics of the water from the upper Tiete, as an input in the form of drinking water produced in eight stations, water treatment plant (WTP), an input for hydropower generation and wastewater generated by different anthropogenic activities. The most important problem of this basin is the wastewater that is released in the Pinheiros river and due to the deficit of 32.41 m3/s (2008) in the treatment of sewage in the metropolitan region of Sao Paulo ('RMSP') which produces one pollutant load of 920 thousand kilograms of BOD per day. The Pinheiros river's flow during the floods and drought has the same destination, the Billings reservoir. However, the legislation for floods and drought periods are different. The first case - floods occurs by the action of full control of the metropolitan region and is supported by the Joint Resolution of Secretaries of State of Sao Paulo (SEE-SMA-SRHSO on 13/03/96) that allows the pumping of water in the following emergencies: (1) estimates of flow of the Tiete river at the point of its confluence with the river Pinheiros, above 160 m3/ s; (2) raised level above 30 cm water level at the confluence with the river Pinheiros. The second case - drought, the Metropolitan Company for Water and Energy (EMAE) Project proposed flotation of the Secretary of State for the Environment (SMA, 2004) to treat 10 m3/ s water originating channel Pinheiros (set/2007 the set / 2008) by means of flotation technology in flow. Using information based on Environmental Sanitation Great Sao Paulo (SANEGRAN) and data from the operation of the prototype flotation system Pinheiros-Billings (Project QAPB), concluded that the environmental impact of the reservoir Billings for the load of pollutants (mass per second) pumped after the flotation of the Pinheiros river water was always lower than that observed in the flood control operation. The treatment presented by flotation removal of 91% for total phosphorus, 90% for E

  9. Critical heat flux in bottom heated two-phase thermosyphon. Improvement in critical heat flux due to concentric tube; Katan shuchu kanetsugata niso netsu syphon no genkai netsu ryusoku. Nijukan ni yoru genkai netsu ryusoku no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Monde, M.; Mitsutake, Y. [Saga University, Saga (Japan). Faculty of Science and Engineering

    2000-02-25

    An experiment has been carried out to elucidate the critical heat flux (CHF) of an open two-phase thermosyphon with a bottom heated chamber in which heat is absorbed by evaporation of liquid. Another objective is to enhance the CHF using a concentric-tube by which counter-current flow of vapor and liquid in the throat of the chamber can be controlled well. The CHF data are measured for the saturated liquid of R 113 at a different pressure and different configuration of concentric tubes. The CHF data without the inner tube are in good agreement with the existing correlation and analytical result. The CHF increases by as much as several times of the CHF without the inner tube with an increase in the inner tube diameter up to a certain diameter of the inner tube and then decreases continuously as the inner tube diameter approaches the outer tube diameter. The optimum diameter of inner tube exists at which the CHF is maximum. (author)

  10. APLICAÇÃO DO METODO DE ANÁLISE HIERARQUICA (MAH NA ANALISE E AVALIAÇÃO DE IMPACTOS AMBIENTAIS DOS SISTEMAS DE TRANSPORTES URBANOS

    Directory of Open Access Journals (Sweden)

    Dominique Mouette

    2010-04-01

    Full Text Available

    O estudo de impacto ambiental envolve uma grande quantidade de critérios e parâmetros, sendo necessário o trabalho conjunto de uma equipe multidisciplinar. A complexidade dos impactos decorrentes dos sistemas de transporte urbanos que possuem características e magnitudes muito diferentes, somada a não obrigatoriedade do estudo, fizeram com que poucos estudos fossem efetuados e tornou evidente a necessidade de metodologias de avaliação dos mesmos. Este estudo aborda a utilização do Método de Analise Hierárquica, um procedimento multicriterial na analise e avaliação dos impactos ambientais dos sistemas de transportes urbanos.

    ABSTRACT

    The study of environmental impacts involves a large amount of criteria and parameters being necessary to work with a multisciplinary team. The impacts due to urban transportation are very complex having different characteristics and magnitude, besides that, in Brazil, these studies are not obliged by law. These facts leads to few studies of the environmental impacts and evidences the necessity of developing methodologies which makes possible the impact's evaluation. This study refers to the utilization of the Analytical Hierarchy Process, a multicriteria procedure in the evaluation and analysis of environmental impacts in urban transportation.

  11. Experimental study of high-performance cooling system pipeline diameter and working fluid amount

    Science.gov (United States)

    Nemec, Patrik; Malcho, Milan; Hrabovsky, Peter; Papučík, Štefan

    2016-03-01

    This work deals with heat transfer resulting from the operation of power electronic components. Heat is removed from the mounting plate, which is the evaporator of the loop thermosyphon to the condenser and by natural convection is transferred to ambient. This work includes proposal of cooling device - loop thermosyphon, with its construct and follow optimization of cooling effect. Optimization proceeds by selecting the quantity of working fluid and selection of diameters vapour line and liquid line of loop thermosyphon.

  12. Review of SC/RF refrigeration systems

    International Nuclear Information System (INIS)

    Byrns, R.A.

    1990-01-01

    A short review is given of historical events in accelerator and cryogenic developments at both Stanford and Berkeley. Methods of refrigeration between 1.85 K and 4.5 K together with modern techniques and improvements are discussed. Where the decade of the 70's was the era of the screw compressor, the 80's can be considered that of the cold vacuum pump for superfluid cooling. Distribution methods are of major importance, and arguments can be made for bath or tube cooling, two-phase, thermo-syphon, supercritical or superfluid. System design affects reliability, safety and operating stability. Distribution costs and heat loads can be a large part of system totals. Some specific system descriptions are included. (author)

  13. A model for cooling systems analysis under natural convection

    International Nuclear Information System (INIS)

    Santos, S.J. dos.

    1988-01-01

    The present work analyses thermosyphons and their non dimensional numbers. The mathematical model considers constant pressure, single-phase incompressible flow. It simulates both open and closed thermosyphons, and deals with heat sources like PWR cores of electrical heaters and cold sinks like heat exchangers or reservoirs. A computer code named STRATS was developed based on this model. (author)

  14. Measurement analysis using the Fricke dosemeter; Analise de medicoes com o dosimetro Fricke

    Energy Technology Data Exchange (ETDEWEB)

    Pedrosa, G A.C. , [Instituto Nacional de Metrologia (INMETRO), Rio de Janeiro, RJ (Brazil); Dantas, C.C. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear], e-mail: ccd@ufpe.br; Campos, C.A. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: auster@elogica.com.br

    2003-07-01

    The Fricke dosemeter has been used for absolute determination of the radiation dose between 40 and 350 Gy for X-rays, Gamma rays and fast electrons energies. The great inconvenient of that dosimetric system is the impossibility of using for measurements of exposure or low dose rates. A Fricke dosimetry system was implanted at the Nuclear Sciences Regional Center (CRCN), in Recife, Pernambuco state, Brazil, for the determination of radiation doses for spectrometry and mass dosimetry with plasma source. The statistical analysis of the obtained results have shown that using the spectrometric method that system cna be used for maintenance of factors of CRCN standard calibrations and the dose assessment thru mail system of radiotherapy centers of the country.

  15. Electric power transport costs - methodologies analysis; Custos de transporte de energia eletrica: analise de metodologias

    Energy Technology Data Exchange (ETDEWEB)

    Takahata, Dario

    1997-07-01

    The dissertation presents the aspects related to the restructuring of power systems in terms of international experiences, and the possible implications for the definition of the new power system in Brazil. The experience shows that the reform in various countries has started from the sector deverticalization, together with the transmissions open access scheme. The retrospect of researched countries indicates that the transmissions remuneration is based on a methodology that recovers the operative cost of transmission transactions, along with an additional amount that take into account the cost of the existing transmission system. The following countries have been analyzed: Chile, Norway, England and Argentina. This work also shows the current situation in Brazil, as in terms of tariffs, as regarding the power system organizational structure, as well as a preliminary proposal conceived by SINTREL (National System of Electrical Energy Transmission) to evaluate the transmission transaction cost. This dissertation ended with comments and conclusions, depicting a future program which might be followed, considering the aspects quoted above and the peculiarities of brazilian power system. (author)

  16. Qualitative analysis of the OSPAR pipeline reliability; Analise gerencial da confiabilidade das bombas do oleoduto OSPAR

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rubens Roberto Faria; Silva, Gilmar Divino da [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The assets, the example of the pumps of external transference, of the Maritime Terminal of Sao Francisco do Sul - Brazil, in operation have 30 years, lacked of management qualitative evaluation, under the optics of the maintenance aiming at to endow the Coordination with Maintenance of better information, for the taking of decision, related to the availability of the rotating equipment. Considering the available data in the system of information, of the data base of operations and maintenance and internationally accepted data base as the OREDA, we evaluate the failure rates, the parameters of the statistical data and quality of the interventions of the maintenance, man power and procedures, being that we arrive the conclusion of that although old the equipment of the transference system meets in good conditions of availability, proving the effectiveness of the maintenance applied to the same ones. (author)

  17. Theoretical and experimental analysis of the induction generators; Analise teorica e experimental do gerador de inducao

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Marcel; Martins Neto, Luciano; Calixto, Wesley Pacheco; Gontijo, Andre Luiz; Alves, Aylton Jose [Universidade Federal de Uberlandia (LMEE/FEELT/UFU), MG (Brazil). Fac. de Engenharia Eletrica. Lab. de Maquinas Eletricas Especiais], E-mails: marcel@mestrado.ufu.br, lmn@ufu.br, wpcalixto@ieee.org, aja@cefetgo.br

    2009-10-15

    Due to its lower costs, robustness, reduced maintenance and easy operation, the induction generator shows to be an economic alternative in small power generator systems. This work presents the initial phase of pertinent studies about the employment of the induction generator directly connected to the electrical power grid in a pilot project to be implemented at the Santa Luzia SHP. A project that aims to raise relevant operational aspects and to evidence some advantages about the employment of the induction generator in small power generator systems. This phase comprises the experimentation of an induction generator directly connected to the power grid in a laboratorial scale, plus a computational modeling which represents the same. This computational modeling takes into account loads variations which are being supplied by the generator, unbalance between phases and magnetic saturation effects, such as harmonic distortions in the generated currents. From the experimental model collected data, a theoretical-experimental confrontation of the computational modeling is made, where quantitative and qualitative analyses about the operational characteristics of the machine are made. The results of this work will head the operation and supervision of the SHP induction machine. (author)

  18. Energetic analysis of a wood fired grain drier; Analise energetica de secador de graos a lenha

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Alessandro Torres [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Grupo de Pesquisas em Ambiencia do Oeste do Parana], e-mail: atcampos3@yahoo.com.br; Melo, Evandro de Castro; Sousa e Silva, Juarez de [Universidade Federal de Vicosa (UFV), Vicosa, MG (Brazil). Dept. de Engenharia Agricola

    2004-07-01

    Aiming at the attendance of a small and medium size group of producers a four chambers fixed-bed dryer prototype with a mechanical revolving system was designed, constructed and energy performance tested. During drying for the prototype test, using coffee the revolving operation proceeded in two chambers which were connected to the dryer plenum at different positions and at a regular three-hours intervals; the other chambers remained static. The dryer operated at a drying-air temperature of 43 deg C and an air-flow of 21 m3 min-1 m-2. In the realized test the product moisture content was reduced from 43.1 to 12.7% w.b. over a 42-hours period. The specific energy consumption was 12.752 kJ per kilogram of evaporated water. The obtained results showed that chamber 1 which was submitted to the revolving operation presented the best work conditions due to your plenum connection position. (author)

  19. Thermoeconomic analysis incorporating the concept of ecological efficiency; Analise termoeconomica incorporando o conceito de eficiencia ecologica

    Energy Technology Data Exchange (ETDEWEB)

    Villela, I.A.C. [University of Sao Paulo (EEL/USP), Lorena, SP (Brazil). Coll. of Engineering. Dept. of Environment Science ], Email: iraides@debas.eel.usp.br; Silveira, J.L. [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Dept. of Energy], Email: joseluz@feg.unesp.br

    2009-07-01

    A comparative analysis of the pollution resulting from the natural gas combustion for a thermoelectric power plant (230 MW) by utilizing the combined cycle (CC) and recovering kettle, with no burning and with fuel complementary burning. Initially the CO{sub 2}, SO{sub 2}, NO{sub x} and Particulate Matter emission levels are determined. Later, the thermoelectric power plant environmental impact is evaluated through the utilization of a methodology based on the ecological efficiency ({epsilon}), parameter that integrates in a single coefficient the aspects that define the environmental impact intensity, with basis on the fuel utilized, combustion technology, pollution index and power plant thermodynamic efficiency. The objective is to apply the concept of ecological efficiency in a thermoeconomic analysis method which utilizes function diagram and allows the estimation of the electricity production cost. It is concluded that the use of a system with no complementary burning is better than the one with complementary burning, both from the ecological and the economical points of view. (author)

  20. Analysis of numerical solutions for Bateman equations; Analise de solucoes numericas para as equacoes de Bateman

    Energy Technology Data Exchange (ETDEWEB)

    Loch, Guilherme G.; Bevilacqua, Joyce S., E-mail: guiloch@ime.usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (IME/USP), Sao Paulo, SP (Brazil). Departamento de Matematica Aplicada. Instituto de Matematica e Estatistica; Hiromoto, Goro; Rodrigues Junior, Orlando, E-mail: rodrijr@ipen.br, E-mail: hiromoto@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The implementation of stable and efficient numerical methods for solving problems involving nuclear transmutation and radioactive decay chains is the main scope of this work. The physical processes associated with irradiations of samples in particle accelerators, or the burning spent nuclear fuel in reactors, or simply the natural decay chains, can be represented by a set of first order ordinary differential equations with constant coefficients, for instance, the decay radioactive constants of each nuclide in the chain. Bateman proposed an analytical solution for a particular case of a linear chain with n nuclides decaying in series and with different decay constants. For more complex and realistic applications, the construction of analytical solutions is not viable and the introduction of numerical techniques is imperative. However, depending on the magnitudes of the decay radioactive constants, the matrix of coefficients could be almost singular, generating unstable and non convergent numerical solutions. In this work, different numerical strategies for solving systems of differential equations were implemented, the Runge-Kutta 4-4, Adams Predictor-Corrector (PC2) and the Rosenbrock algorithm, this last one more specific for stiff equations. Consistency, convergence and stability of the numerical solutions are studied and the performance of the methods is analyzed for the case of the natural decay chain of Uranium-235 comparing numerical with analytical solutions. (author)

  1. Automated analysis of pumping tests; Analise automatizada de testes de bombeamento

    Energy Technology Data Exchange (ETDEWEB)

    Sugahara, Luiz Alberto Nozaki

    1996-01-01

    An automated procedure for analysis of pumping test data performed in groundwater wells is described. A computer software was developed to be used under the Windows operational system. The software allows the choice of 3 mathematical models for representing the aquifer behavior, which are: Confined aquifer (Theis model); Leaky aquifer (Hantush model); unconfined aquifer (Boulton model). The analysis of pumping test data using the proper aquifer model, allows for the determination of the model parameters such as transmissivity, storage coefficient, leakage coefficient and delay index. The computer program can be used for the analysis of data obtained from both pumping tests, with one or more pumping rates, and recovery tests. In the multiple rate case, a de superposition procedure has been implemented in order to obtain the equivalent aquifer response for the first flow rate, which is used in obtaining an initial estimate of the model parameters. Such initial estimate is required in the non-linear regression analysis method. The solutions to the partial differential equations describing the aquifer behavior were obtained in Laplace space, followed by numerical inversion of the transformed solution using the Stehfest algorithm. The data analysis procedure is based on a non-linear regression method by matching the field data to the theoretical response of a selected aquifer model, for a given type of test. A least squared regression analysis method was implemented using either Gauss-Newton or Levenberg-Marquardt procedures for minimization of a objective function. The computer software can also be applied to multiple rate test data in order to determine the non-linear well coefficient, allowing for the computation of the well inflow performance curve. (author)

  2. Integrated Management System in construction company-effective tool of quality, environment and safety level improving

    OpenAIRE

    Gašparík, Jozef

    2009-01-01

    Contribution Presents the struCture of integrated M anageMent systeM ( iMs) according to international standards ISO 9001:2008, ISO 14001:2004 and STN OHSAS 18001:2009, which consists of 3 management systems focused to quality, environment and safety of building processes. The purpose of paper is to describe basic steps concerning the development of IMS. Paper analises basic processes of IMS like company vision, IMS planning, implementing, monitoring, revive and improving. The paper presents ...

  3. Analise van die Tswanaraaisel

    Directory of Open Access Journals (Sweden)

    S. A. Swanepoel

    1984-05-01

    Full Text Available ’n Strukturele, stilistiese en funksionele bcskrywing van die Twanaraaisel bring mee dat daar aan die volgende aspekte aandag gegee moet word: •\tWat is ’n raaisel en lioe word dit in Tswana genoem. •\tTot watter studiegebied en literere genre hoort die raaisel en watter subvorme kan vir Tswana onderskei word. •\tHoe sien die struktuur van Tswanaraaisels daar uit. •\tDeur wie, waar, wanneer en hoe word Tswanaraaisels voorgedra. •\tWatter stilistiese kenmcrke kan in Tswanaraaisels onderskei word. •\tWatter funksies vervul raaisels in ’n Tswanagcmeenskap.

  4. Development of a system of programs HAMMER - ORIGEN - 2 system

    International Nuclear Information System (INIS)

    Guimaraes, L.N.F.

    1984-07-01

    The development of a system of programs (Hamor-2) to calculate precision inventory of LWR reactors is presented. The Hamor-2 code generates with the Hammer-technion code the four (4) energy groupe effective cross section of the actinides: U-235, U-236, U-238, Pu-239, Pu-240, Pu-241, Pu-242. Hamor-2 collapses the four group energy effective cross section to one group energy effective cross section. Hamor-2 calculates with origen-2 the new concentrations for the actinides using the one group energy effective cross section. Two PWR reactors were analised. (HBR, KWO). The discrepancy between the final actinides conentration results calculated by Hamor-2 and the results of measures finded in the references were calculated. That discrepancies have been compared with the discrepancy between : the final actinide concentration results calculated by Origen-2 and some measured results finded in the references. (E.G.) [pt

  5. Evaporation and condensation devices for passive heat removal systems in nuclear power engineering

    International Nuclear Information System (INIS)

    Gershuni, A.N.; Pis'mennyj, E.N.; Nishchik, A.P.

    2016-01-01

    The paper justifies advantages of evaporation and condensation heat transfer devices as means of passive heat removal and thermal shielding in nuclear power engineering. The main thermophysical factors that limit heat transfer capacity of evaporation and condensation systems have been examined in the research. The results of experimental studies of heat engineering properties of elongated (8-m) vertically oriented evaporation and condensation devices (two-phase thermosyphons), which showed a high enough heat transfer capacity, as well as stability and reliability both in steady state and in start-up modes, are provided. The paper presents the examples of schematic designs of evaporation and condensation systems for passive heat removal and thermal shielding in application to nuclear power equipment

  6. The cryogenic system for the superconducting solenoid magnet of the CMS experiment

    CERN Document Server

    Delikaris, D; Passardi, Giorgio; Lottin, J C; Lottin, J P; Lyraud, C

    1998-01-01

    The design concept of the CMS experiment, foreseen for the Large Hadron Collider (LHC) project at CERN, is based on a superconducting solenoid magnet. The large coil will be made of a four layers winding generating the 4 T uniform magnetic induction required by the detector. The length of the solenoid is 13 m with an inner diameter of 5.9 m. The mass kept at liquid helium temperature totals 220 t and the electromagnetic stored energy is 2.7 GJ. The windings are indirectly cooled with a liquid helium flow driven by a thermosyphon effect. The external cryogenic system consists of a 1.5 kW at 4.5 K (entropy equivalent) cryoplant including an additional liquid nitrogen precooling unit and a 5000 litre liquid helium buffer. The whole magnet and cryogenic system will be tested at the surface by 2003 before final installation in the underground area of LHC.

  7. On the field performance of PV water pumping system in Libya

    International Nuclear Information System (INIS)

    Sbeta, M.; Sasi, S.

    2012-01-01

    This paper presents the measured performance of an experimental PV water pumping system of 1200Wp installed in the north-east of Libya. Both the monthly and hourly measured data of the system performance are presented and analised, and the over-all system efficiency has been calculated as monthly and daily averages. The monthly average output of the system has been estimated and compared with measured data. The economic analysis of the system has been carried out and the specific water discharge cost (SDC) has been determined, the obtained SDC was very competitive with the published SDC of the PV water pumping projects in some countries. The obtained results have demonstrated the technical and economic feasibility of using the PV systems for water pumping especially in the remote areas of high potential of solar insolation.(author)

  8. Identification and analysis of the environmental management documentation related to the activities of environmental and chemical analysis laboratories; Identificacao e analise da documentacao pertinente a gestao ambiental relacionada as atividades de laboratorios de analises quimicas e ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Otomo, Juliana Ikebe; Brandalise, Michele; Romano, Renato Lahos; Marques, Roberto; Szarota, Rosa Maria; Raduan, Rosane Napolitano; Salvetti, Tereza Cristina; Egute, Nayara dos Santos; Almeida, Josimar Ribeiro de; Aquino, Afonso Rodrigues de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: araquino@ipen.br

    2009-08-15

    In the last years, many documents were elaborated by several countries and entities, concerning the environmental question. The implantation of and Environmental Management System requires specific documentation so that a company or laboratory can adjust themselves to the environmental quality. For laboratories of chemical, environmental analyses and also nuclear materials, the needs of attendance to the requirements of the following municipal, state and federal institutions were identified: Corpo de Bombeiros, CNEN - Comissao Nacional de Energia Nuclear, IBAMA - Instituto Brasileiro do Meio Ambiente e dos Recursos Renovaveis, ANVISA - Agencia Nacional de Vigilancia Sanitaria, PMSP - Prefeitura Municipal de Sao Paulo e a CETESB - Companhia Ambiental do Estado de Sao Paulo. (author)

  9. Energy analysis in Cynodon dactylon (L.) Pers hay production; Analise energetica na producao de feno de Cynodon dactylon (L.) Pers

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Alessandro T. [UNIOESTE, Marechal Candido Rondon, PR (Brazil). Centro de Ciencias Agrarias]. E-mail: atcampos3@yahoo.com.br; Saglietti, Jose R.C.; Bueno, Osmar C. [UNESP, Botucatu, SP (Brazil). Facudade de Ciencias Agronomicas; Campos, Aloisio T. [EMBRAPA - Gado de leite, Juiz de Fora, MG (Brazil)

    2005-05-15

    The aim of this work was to characterize the energy consumption related to the introduction, development, hay processing and storage of Cynodon dactylon (L.) Pers allied to the analysis of the energetic efficiency. The data used in this project were collected from EMBRAPA Gado de Leite, localized in Coronel Pacheco, Minas Gerais, Brazil. The data were obtained from a seven year period of an intensive system of milk production. Energetic coefficients were used to generate the survey and several matrix components obtained from pertinent literature. The direct energy, related to the inputs, showed more efficient participation on the energetic matrix than the indirect energy and the percentages were 94.64 and 5.31, respectively. Farm tractor was the main indirect energy consumer, which is responsible for turning on all the equipment, followed by the irrigation system. The energetic efficiency presented by the whole system was 4.2, being considered positive and demonstrating that the agriculture ecosystem is sustainable. Most of the direct energy employed in this system was oil derived on fuel form. There was, however, a great consume of another oil derived energy such as fertilizer, but mainly on the nitrogen form (28.89% of the total employed energy). (author)

  10. Load curves analysis under operational and economics focus; Analise de curvas de carga sob enfoques operativos e economicos

    Energy Technology Data Exchange (ETDEWEB)

    Matos, R S; Cardoso, A F; Fleury, M E.V. [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1988-12-31

    This work aims to present the analysis of load curves performed by the short term planning sectors of several subsidiaries, independently of the methodologies used. In order to do so some peculiar occurrences were selected which show the influence of factors that are external to the electric power system. In such way, the analysis of past situations proves to be an important tool in the forecasting work so that a better planning may be achieved. 13 figs., 2 tabs.

  11. Analysis of records of external occupational dose records in Brazil; Analise dos registros de dose ocupacional externa no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Mauricio, Claudia L.P.; Silva, Herica L.R. da, E-mail: claudia@ird.gov.br, E-mail: herica@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ),Rio de Janeiro, RJ (Brazil); Silva, Claudio Ribeiro da, E-mail: claudio@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Brazil, a continental country, with actually more than 150,000 workers under individual monitoring for ionizing radiation, has implemented in 1987 a centralized system for storage of external occupational dose. This database has been improved over the years and is now a web-based information system called Brazilian External Occupational Dose Management Database System - GDOSE. This paper presents an overview of the Brazilian external occupational dose over the years. The estimated annual average effective dose shows a decrease from 2.4 mSv in 1987 to about 0.6 mSv, having been a marked reduction from 1987 to 1990. Analyzing by type of controlled practice, one sees that the medical and dental radiology is the area with the largest number of users of individual monitors (70%); followed by education practices (8%) and the industrial radiography (7%). Additionally to photon whole body monitoring; neutron monitors are used in maintenance (36%), reactor (30%) and education (27%); and extremity monitors, in education (27%), nuclear medicine (22%) and radiology (19%). In terms of collective dose, the highest values are also found in conventional radiology, but the highest average dose values are those of interventional radiology. Nuclear medicine, R and D and radiotherapy also have average annual effective dose higher than 1 mSv. However, there is some very high dose values registered in GDOSE that give false information. This should be better analyzed in the future. Annual doses above 500 are certainly not realistic. (author)

  12. Energy assessment of nitrogen variable rate fertilization on wheat; Analise energetica da aplicacao de nitrogenio em taxa variavel em trigo

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, A.F.; Karam, E.H.; Romanelli, T.L.; Molin, J.P. [Escola Superior de Agricultura Luiz Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Engenharia de Biossistemas], Email: andrecolaco@usp.br; Povh, F.P. [Fundacao ABC Pesquisa e Desenvolvimento Agropecuario, Castro, PR (Brazil)

    2011-07-01

    Precision Agriculture (PA) is a technique that can reduce the inputs utilization in agriculture production, including the nitrogen fertilizer consume. Great importance is given to this fertilizer, due to its contribution on energy input in agriculture. Methodologies based on the calculation of energy flow of agriculture systems are capable to identify management practices that use energy more efficiently. So, this study's objective is to evaluate the variable-rate nitrogen fertilization on wheat, using energy assessment. This study was carried on in two wheat fields, in which the fertilization was done adopting strips alternated by conventional method (single nitrogen dose) and by nitrogen variable-rate technology. Thus, the input and output energy in the system, energy balance, energy return on investment (EROI) and incorporated energy were determined for each geo-referenced point within the fields. Results showed that less energy was demanded when using variable-rate technology, due to the nitrogen saving, providing greater energy balance, EROI and lower incorporated energy on the areas managed using PA. The energy assessment showed to be an important tool to evaluate systems that use PA, because it is capable of monitoring crops energy potential. (author)

  13. Energy analysis of tubular digesters using swine residues; Analise energetica de biodigestores tubulares usando dejetos de suinos

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Alessandro Torres; Daga, Jacir [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Grupo de Pesquisas em Ambiencia do Oeste do Parana; Campos, Aloisio Torres de [EMBRAPA Gado de Leite, Juiz de Fora, MG (Brazil). Grupo Pesquisador em Educacao Ambiental; Santos, Elenara Pinto dos; Casimiro, Evandro Luiz Nogarolli; Nagae, Ricardo Yuiti; Weiss Filho, Waldemiro [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Centro de Ciecias Agraras

    2004-07-01

    Overcoming another financial crisis, the swine production has the great challenge, in this and next decades, of also reaching the sustainability in the ecosystem ambit. The Parana State/Brazil west area is known because of it's residues high production, with high pollution level, it possesses the added difficulty of presenting high concentration of animals, inserted in production centers in reduced areas. However, this situation reversion, changing the 'trouble called residue' in a 'energy source solution', by means of digesters, became a reality, with the initiative of some producers and researchers. Present work objective was to evaluate the energy production, by means of the digesters use, as alternative energy co-generation. The work was developed at a commercial farm located at the Parana State west area, with 1,700 sows, in an piglet unit producing, with production of 3,400 piglet per mouth. The studied system is constituted by two parallel digesters, with continuous flow and total capacity of 1,275 m3 per digester, with 30 days of hydraulic retention time. The generated biogas feeds a 4.1 cc engine, with six cylinders, 80 cv, 3,600 rpm, coupled to an generator, that constitutes an 50 kW electric engine. The system promoted a 58% reduction of chemical demand of oxygen. The daily gas production estimated was 208 m3, with production of electric energy of 35.2 kWh per day. For most of the year, the system has the potential of provisioning the farm of electricity for all its needs, promoting economy that is transformed into income for the activity. (author)

  14. Analysis of energetic efficiency in stenters of textile industry; Analise de eficiencia energetica em ramas de industria textil

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Antonio Rogerio; Ferraz, Andre; Rocha, Ivan; Azevedo, Jorge; Oshiro, Hugo K.; Konishi, Ricardo; Piazza, Walter; Lehmkuhl, Willian [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil)

    2011-12-21

    This paper presents the research on the use of alternative energy within the textile industry: a strategy aimed at reducing costs and securing market share. The use of natural gas allows for the direct heating and drying of textiles through convection, instead of the conventional indirect heating method of thermal fluids. This measure alone reduces significantly the energy costs and grants the process superior efficiency and sustainability. This case examines the improvements to the process of drying textiles through thermal equipment called stenters, whose purpose is to remove humidity from the cloth during its fabrication. As such, SCGAS, in association with FURB, has performed an operational and technological evaluation of the drying process used by a customer enterprise. The data collected enabled the researchers to map all sources (inputs and outputs) of mass and energy for each different stenter. This composed the basis for the analysis done and the subsequent proposal of improvements, which varied from the conversion of stenter from indirect to direct heating and the development of even more energy efficient solutions for the direct heating system. The data obtained shows that, for the indirect heating system, 28% of the thermal energy produced could be recovered, given the temperature of the exhaust gases reached 360 deg C. The indirect heating stenters presented energy efficiency between 24% and 27%, whiles the direct heating ones presented between 27,4% and 34,8%. Additionally, if an automated control system for the natural gas and oxidizing air flows was to be installed, it would guarantee greater quality combustion with a significant increase in energy efficiency, as well as a decrease in carbon monoxide emissions by a factor of eight. (author)

  15. Electric energy tariffs - critical analysis and methodological proposition; Estrutura de tarifas de energia eletrica. Analise critica e proposicoes metodologicas

    Energy Technology Data Exchange (ETDEWEB)

    Fugimoto, Sergio Kinya

    2010-07-01

    Currently, the electric energy sector is preparing for the third round of the distributors tariff revisions. Since the regulatory environment is more consolidated in terms of required revenue, the agents are turning their attention to the necessary adjustment and correction of the tariff structure. In fact, ANEEL (regulatory agency) set topics for R and D projects considered strategic for the development of national energy sector, among them, the Tariff Structure Project. Recently, the regulatory agency also announced public hearings dealing with the costs allocation, price signals and tariffs for low-voltage consumers. In line with this debate, the thesis finds to analyze the methodology for calculating tariffs, systematizing knowledge dispersed in various references. For this, it discusses the major aspects of peak pricing theory, including American, British and French approaches, and researches the connection between the logic built into the costs allocation by hour and the criteria for electricity distribution system planning. Aiming to reflect the costs of each customer type, indicating a better utilization of the distribution system, are proposed improvements and innovation whose highlights are: shifting the idea that expansion costs should be only allocated in peak time of the system, setting the periods after calculating the costs, changing how to derive the reference charges by average aggregation of the costs and applying the methodology on altered load curves. Finally, this thesis seeks to prove that the current methodology, although designed by the time in which the electricity sector was aggregated, can be adapted according to the proposed improvements and innovations, and thus applied to the current environment in which electric energy businesses and tariffs are separated in generation, transmission, and distribution and retail areas. (author)

  16. Energy analysis of tubular digesters using swine residues; Analise energetica de biodigestores tubulares usando dejetos de suinos

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Alessandro Torres; Daga, Jacir [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Grupo de Pesquisas em Ambiencia do Oeste do Parana], e-mail: atcampos3@yahoo.com.br; Campos, Aloisio Torres de [EMBRAPA Gado de Leite, Juiz de Fora, MG (Brazil). Grupo Pesquisador em Educacao Ambiental; Santos, Elenara Pinto dos; Casimiro, Evandro Luiz Nogarolli; Nagae, Ricardo Yuiti; Weiss Filho, Waldemiro [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Centro de Ciecias Agraras

    2004-07-01

    Overcoming another financial crisis, the swine production has the great challenge, in this and next decades, of also reaching the sustainability in the ecosystem ambit. The Parana State/Brazil west area is known because of it's residues high production, with high pollution level, it possesses the added difficulty of presenting high concentration of animals, inserted in production centers in reduced areas. However, this situation reversion, changing the 'trouble called residue' in a 'energy source solution', by means of digesters, became a reality, with the initiative of some producers and researchers. Present work objective was to evaluate the energy production, by means of the digesters use, as alternative energy co-generation. The work was developed at a commercial farm located at the Parana State west area, with 1,700 sows, in an piglet unit producing, with production of 3,400 piglet per mouth. The studied system is constituted by two parallel digesters, with continuous flow and total capacity of 1,275 m3 per digester, with 30 days of hydraulic retention time. The generated biogas feeds a 4.1 cc engine, with six cylinders, 80 cv, 3,600 rpm, coupled to an generator, that constitutes an 50 kW electric engine. The system promoted a 58% reduction of chemical demand of oxygen. The daily gas production estimated was 208 m3, with production of electric energy of 35.2 kWh per day. For most of the year, the system has the potential of provisioning the farm of electricity for all its needs, promoting economy that is transformed into income for the activity. (author)

  17. Incidents in nuclear research reactor examined by deterministic probability and probabilistic safety analysis; Incidentes em reatores nucleares de pesquisa examinados por analise de probabilidade deterministica e analise probabilistica de seguranca

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Valdir Maciel

    2010-07-01

    This study aims to evaluate the potential risks submitted by the incidents in nuclear research reactors. For its development, two databases of the International Atomic Energy Agency, IAEA, were used, the Incident Report System for Research Reactor and Research Reactor Data Base. For this type of assessment was used the Probabilistic Safety Analysis (PSA), within a confidence level of 90% and the Deterministic Probability Analysis (DPA). To obtain the results of calculations of probabilities for PSA, were used the theory and equations in the paper IAEA TECDOC - 636. The development of the calculations of probabilities for PSA was used the program Scilab version 5.1.1, free access, executable on Windows and Linux platforms. A specific program to get the results of probability was developed within the main program Scilab 5.1.1., for two distributions Fischer and Chi-square, both with the confidence level of 90%. Using the Sordi equations and Origin 6.0 program, were obtained the maximum admissible doses related to satisfy the risk limits established by the International Commission on Radiological Protection, ICRP, and were also obtained these maximum doses graphically (figure 1) resulting from the calculations of probabilities x maximum admissible doses. It was found that the reliability of the results of probability is related to the operational experience (reactor x year and fractions) and that the larger it is, greater the confidence in the outcome. Finally, a suggested list of future work to complement this paper was gathered. (author)

  18. Energetic analysis versus exergetic analysis of charcoal blast furnace of V and M do Brazil; Analise energetica versus analise exergetica do alto forno a carvao vegetal da V and M do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Lis Nunes; Silva, Ricardo Junqueira [V e M do BRASIL S.A., Belo Horizonte, MG (Brazil); Franca, Geraldo Augusto Campolina; Lemos, Ricardo Jose Fernandes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2011-12-21

    The energetic analysis is the traditional method of quantification of the energy used in an operation involving physical and chemical processes and transference and/or conversion of energy. Generally used through energetic balance that is based on the first law of thermodynamics to evaluate the energetic efficiency. This balance is used to determine and reduce the loss of energy. Although an energy balance does not provide information about the energy degradation or resources during a process and do not quantify the potential or quality of the energy fluxes and material that flow in a system and come out as products and losses. The exergetic analysis goes beyond the limitations of the first law of thermodynamics. The concept of exergy is based in the second law of thermodynamics. The objective of this paper is to compare the more suitable analysis method aiming the identification of the energy economy potentials and consequently the reduction in the emissions of the greenhouse gases, through the balance of mass, energy and exergy of the blast furnace 1 of V and M do Brazil. (author)

  19. Experimental analysis of a PEM fuel cell 15 W; Analise experimental de uma celula a combustivel PEM 15W

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Raphael Guardini; Bazzo, Edson [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], e-mail: miyake@labcet.ufsc.br, e-mail: ebazzo@emc.ufsc.br

    2006-07-01

    Fuel cells have been considered a promising alternative for electric energy generation. In order to contribute with the development of this technology, a PEM fuel cell was installed and new experiments were carried out at LabCET (Laboratory of Combustion and Thermal System Engineering). Previous results have shown polarization curves identifying the need of rigorous controlling of humidification temperature of the fuel cell. In this paper, new results were carried out considering the use of a fan connected to the fuel cell and possible degradation in the electrolyte, after a relative long time operation. New polarization curves were plotted for comparison with previous results. (author)

  20. Heat Removal Performance of Hybrid Control Rod for Passive In-Core Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Mo; Jeong, Yeong Shin; Kim, In Guk; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2015-10-15

    The two-phase closed heat transfer device can be divided by thermosyphon heat pipe and capillary wicked heat pipe which uses gravitational force or capillary pumping pressure as a driving force of the convection of working fluid. If there is a temperature difference between reactor core and ultimate heat sink, the decay heat removal and reactor shutdown is possible at any accident conditions without external power sources. To apply the hybrid control rod to the commercial nuclear power plants, its modelling about various parameters is the most important work. Also, its unique geometry is coexistence of neutron absorber material and working fluid in a cladding material having annular vapor path. Although thermosyphon heat pipe (THP) or wicked heat pipe (WHP) shows high heat transfer coefficients for limited space, the maximum heat removal capacity is restricted by several phenomena due to their unique heat transfer mechanism. Validation of the existing correlations on the annular vapor path thermosyphon (ATHP) which has different wetted perimeter and heated diameter must be conducted. The effect of inner structure, and fill ratio of the working fluid on the thermal performance of heat pipe has not been investigated. As a first step of the development of hybrid heat pipe, the ATHP which contains neutron absorber in the concentric thermosyphon (CTHP) was prepared and the thermal performance of the annular thermosyphon was experimentally studied. The heat transfer characteristics and flooding limit of the annular vapor path thermosyphon was studied experimentally to model the performance of hybrid control rod. The following results were obtained: (1) The annular vapor path thermosyphon showed better evaporation heat transfer due to the enhanced convection between adiabatic and condenser section. (2) Effect of fill ratio on the heat transfer characteristics was negligible. (3) Existing correlations about flooding limit of thermosyphon could not reflect the annular vapor

  1. Experimental Investigation Into Thermal Siphon Used as an Intermediate Circuit of an Integrated Cooling System Reactor

    International Nuclear Information System (INIS)

    Adamovich, L.A.; Gabaraev, B.A.; Solovjev, S.L.; Shpansky, S.B.

    2002-01-01

    In the paper the results of study in heat transfer capacity of the thermosyphon mock-up which is considered as an intermediate circuit of the reactor under design, are presented. The mock-up design, the test rig and the experimental results are described. It is shown that the simplest mathematical model describes the processes of power transfer by the thermosyphon under certain conditions. (authors)

  2. Chemical analysis of superconductor material by Rietveld method; Analise quimica de material superconductor atraves do metodo de Rietveld

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Junior, E.S.; Gomes Junior, G.G.; Ogasawara, T., E-mail: georges@metalmat.ufrj.b [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Dept. de Eng. Metalurgica e Materiais; Bispo, E.R.; Polasek, A. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil); Amorim, H.S. [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica

    2010-07-01

    Among the main superconducting systems, the system Bi-Sr-Ca-Cu-O is extremely important because it presents two stages of high superconducting critical temperature. To manufacture samples of the superconducting phase (Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}Ox (Bi-2223) were used oxides and carbonates of high purity. The mixture was calcined and sintered for 100-200h in air. To characterize the material we used X-ray diffraction, SEM / EDS and measurement of critical temperature (Tc). The Rietveld method was used for structure refinement, and quantification of phases and to estimate the chemical composition of samples in order to obtain greater control of chemical composition using only the data of X-ray diffraction. The results were compared with the refinement results of X-ray fluorescence and was observed a discrepancy of about 8%. This result indicates that the Rietveld method can be an interesting alternative to perform chemical analysis. (author)

  3. Thermodynamic analysis of hydrates formation in drilling activities; Analise termodinamica da formacao de hidratos em atividades de perfuracao

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Joao Marcelo Mussi; Rossi, Luciano Fernando dos Santos; Morales, Rigoberto E.M. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)], e-mail: joaommussi@yahoo.com.br, e-mail: lfrossi@cefetpr.br, e-mail: rmorales@cefetpr.br

    2006-07-01

    The present work has for objective to present an analysis of hydrates formation in drilling activities. This analysis presents a study of the state conditions for gas hydrates formation in inhibitors containing systems (salts and alcohols, separately). To describe the nonidealities of liquid phase in electrolytic solutions, the activity coefficient model of Debye-Hueckel is used, as [4], and to describe the influence of alcohols in the activity of water, the UNQUAC model is used, as Parrish and Prausnitz. The hydrate phase is described by thermodynamic statistic model of van der Waals and Platteeuw, and the gaseous phase fugacities are modeled by the Peng-Robinson Equation of State. Some results are presented for saline inhibitors, and for methanol and ethyleneglycol. (author)

  4. Economic analysis of a 20 kW gasifier; Analise economica de um gaseificador de 20 kW

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcos Vinicius Miranda da; Rocha, Brigida Ramati Pereira da [Universidade Federal do Para (NEDS/UFPA), Belem, PA (Brazil). Nucleo de Energia para o Desenvolvimento Sustentavel], e-mail: neds@ufpa.br

    2006-07-01

    The gasification of biomass residues has been pointed as an alternative in electricity supplying for small communities of the Amazon region, because it promotes a significant substitution of the diesel oil in the electric power generation. This paper presents an economic analysis of an electricity generation system (gasifier and generator set) of 20 kw that is installed in the community of Jenipauba, in the State of Para. That analysis confirms the economic attractiveness of that energy alternative on the generator sets that operate exclusively with diesel oil. It also shows the impact of the labor law on electricity generation cost, as well as the need of subsidizing the electric power generation, because the community of Jenipauba is very poor. (author)

  5. Data integration for performance analysis of petroleum wells; Integracao de dados para analise de pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Arturo, Naisa Carrillo; Mendes, Jose Ricardo; Morooka, Celso [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Miura, Kazuo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    In this work a new parameter called the System Performance Index is proposed, which allows a more profound study of the performance of petroleum wells. An outstanding characteristic of this parameter is that it uses a large amount of field data measured periodically. This index allows the assessing of the performance and technologies used in the wells. This study presents a comparison of the performance of vertical, directional and horizontal wells. The sand control technologies used in the wells are also evaluated. Finally, the proposed parameter enables a practical analysis that can be implemented as a strategic tool for oil field performance and optimization studies. Data used in this work were kindly supplied by PETROBRAS. (author)

  6. International comparative analysis of E and P regulatory issues; Analise comparativa internacional de aspectos regulatorios em E e P

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Erica Cristina da Fonseca; Almedia, Mariana Lessa Rego de; Baleroni, Rafael Baptista [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Faculdade de Direito

    2004-07-01

    The oil industry is one of the more global sectors of the economy, with its economic agents acting and competing at the same time in many countries. The limitation of available funds for investment and competition in global scale make the host countries adapt some elements of their concession instruments, as a way to attract greater investments. The comparison of legal framework of diverse host countries is an essential part in this process of decision and an indispensable tool to help the host countries in the dispute for the attraction of international investors. Therefore, to place Brazil in this process of global competition between States is necessary the knowledge and the comparison between the conditions offered for its legal system and offered for countries considered as models of attraction of investment. This work intends to offer a comparative study of relevant legal aspects for the oil industry, amongst them: characterization of the concession instrument; reach of the participation of the state-owned company; intervention of the State in the private management. The comparison will be made between countries with different characteristics, to obtain a consolidation of paradigms that helps the evolution of the Brazilian exploration and production legal framework. (author)

  7. Well test: production analysis and allocation measurement; Teste de poco: analise da producao e medicao de apropriacao

    Energy Technology Data Exchange (ETDEWEB)

    Geron, Luis Carlos [Smar Equipamentos Industriais Ltda., Sertaozinho, SP (Brazil). Dept. de Engenharia Aplicacoes; Tateishi, Sergio Hideki [Smar Equipamentos Industriais Ltda, Sertaozinho, SP (Brazil). Dept. de Pesquisa e Desenvolvimento

    2008-07-01

    The well test is an instrument frequently used to evaluate the production capacity of wells and it usually has specific requirements in the flow measurement, that are not necessary in the flow measurement system for custody transfer applications. Starting with the requirement to measure the injected product in the well when it is in the recuperation phase and it also includes compliance to specific standards for allocation measurement, because these hydrocarbon products are not treated as well as that ones in the production streams. Other important issue associated to the well test is the employment of new technologies, that helps to reduce the uncertainty of measurement as digital communication between the field devices and the flow computer through an open protocol as the Foundation Field bus. Another indication of technology evolution in the flow measurement focusing a lower uncertainty is the new version of API MPMS 11.1:2004, that requires calculation with double precision floating point, as well the correction factors with 5 decimal digits. (author)

  8. Analysis of the of bones through 3D computerized tomography; Analise de estrutura ossea atraves de microtomografia computadorizada 3D

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Oliveira, L.F. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica; Alves, J.M. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2009-03-15

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-{mu}TC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-{mu}TC is a powerful technique that can be used to analyze bone microstructures. (author)

  9. Passive Decay Heat Removal System Options for S-CO2 Cooled Micro Modular Reactor

    International Nuclear Information System (INIS)

    Moon, Jangsik; Jeong, Yong Hoon; Lee, Jeong Ik

    2014-01-01

    To achieve modularization of whole reactor system, Micro Modular Reactor (MMR) which has been being developed in KAIST took S-CO 2 Brayton power cycle. The S-CO 2 power cycle is suitable for SMR due to high cycle efficiency, simple layout, small turbine and small heat exchanger. These characteristics of S-CO 2 power cycle enable modular reactor system and make reduced system size. The reduced size and modular system motived MMR to have mobility by large trailer. Due to minimized on-site construction by modular system, MMR can be deployed in any electricity demand, even in isolated area. To achieve the objective, fully passive safety systems of MMR were designed to have high reliability when any offsite power is unavailable. In this research, the basic concept about MMR and Passive Decay Heat Removal (PDHR) system options for MMR are presented. LOCA, LOFA, LOHS and SBO are considered as DBAs of MMR. To cope with the DBAs, passive decay heat removal system is designed. Water cooled PDHR system shows simple layout, but has CCF with reactor systems and cannot cover all DBAs. On the other hand, air cooled PDHR system with two-phase closed thermosyphon shows high reliability due to minimized CCF and is able to cope with all DBAs. Therefore, the PDHR system of MMR will follows the air-cooled PDHR system and the air cooled system will be explored

  10. Implementation of statistical analysis methods for medical physics data; Implementacao de metodos de analise estatistica para dados de fisica medica

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Marilia S.; Pinto, Nivia G.P.; Barroso, Regina C.; Oliveira, Luis F., E-mail: mariliasilvat@gmail.co, E-mail: lfolive@oi.com.b, E-mail: cely_barroso@hotmail.co, E-mail: nitatag@gmail.co [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2009-07-01

    The objective of biomedical research with different radiation natures is to contribute for the understanding of the basic physics and biochemistry of the biological systems, the disease diagnostic and the development of the therapeutic techniques. The main benefits are: the cure of tumors through the therapy, the anticipated detection of diseases through the diagnostic, the using as prophylactic mean for blood transfusion, etc. Therefore, for the better understanding of the biological interactions occurring after exposure to radiation, it is necessary for the optimization of therapeutic procedures and strategies for reduction of radioinduced effects. The group pf applied physics of the Physics Institute of UERJ have been working in the characterization of biological samples (human tissues, teeth, saliva, soil, plants, sediments, air, water, organic matrixes, ceramics, fossil material, among others) using X-rays diffraction and X-ray fluorescence. The application of these techniques for measurement, analysis and interpretation of the biological tissues characteristics are experimenting considerable interest in the Medical and Environmental Physics. All quantitative data analysis must be initiated with descriptive statistic calculation (means and standard deviations) in order to obtain a previous notion on what the analysis will reveal. It is well known que o high values of standard deviation found in experimental measurements of biologicals samples can be attributed to biological factors, due to the specific characteristics of each individual (age, gender, environment, alimentary habits, etc). This work has the main objective the development of a program for the use of specific statistic methods for the optimization of experimental data an analysis. The specialized programs for this analysis are proprietary, another objective of this work is the implementation of a code which is free and can be shared by the other research groups. As the program developed since the

  11. Retoriek, retoriese analise en prediking

    Directory of Open Access Journals (Sweden)

    A. B. du Toit

    1992-06-01

    Full Text Available In characterising rhetoric, its persuasive intent should be highlighted because the persuasive element is true of all three rhetorical genera. Graeco-Roman pupils were well-trained in the rhetorical arts and it can be accepted that Paul also had a working knowledge of rhetoric. Rhetorical analysis of the New Testament attempts to study the texts of the New Testament in the light of rhetorical features, as developed by the classical theorists and refined by a modern scholar like Perelman. Since the 1970's rhetorical analysis of the New Testament has flourished, although approaches have varied considerably and not all efforts were convincing. Nevertheless, it has become clear that the rhetorical approach can enrich our understanding of the New Testament, and especially of its letters, considerably. Examples from Romans and Galatians are presented to underscore this point. Since preaching, like rhetoric, aims at convincing and persuading an audience, rhetoric can provide us with important stimuli for the praxis of preaching, as can be demonstrated from the five prescribed phases of preparing a public speech, as well as from the three modes of persuasion: logos, ethos and pathos.

  12. Information management system for the analysis of the program of electric power transmission construction; Sistema gerencial de informacao para analise do programa de obras de transmissao

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Luiz A. Pecorelli; Lima Junior, Moacir P.; Kayat, Julio; Berer, Ricardo; Sondermann, Luiz O. [FURNAS, Rio de Janeiro, RJ (Brazil)

    1993-12-31

    The management of an implementation and coordination program for electric power transmission lines construction needs to have access to up to date information in several areas. Aiming to attend these basic requisites a data base computer program was developed. This work describes such program 7 refs., 4 figs.

  13. Resonance analysis of the transformers winding owing of system transients; Analise de ressonancia de parte de enrolamentos de transformadores devido a transitorio no sistema

    Energy Technology Data Exchange (ETDEWEB)

    Alves, M F; Ribeiro, E E [MF Consultoria Ltda (Brazil); Aguiar Campos, W de [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1992-12-31

    An analysis of the damage on power transformer winding during occurrence of electrical transients in substations, its causes and an analysis of its occurrence situations are presented. Results of studies in the substation Ouro Preto 2, made by CEMIG (Companhia Energetica de Minas Gerais) aiming an analysis of the possibility to occur damage in transformers winding are also reported 6 refs., 8 figs., 1 tab.

  14. A neural networks based ``trip`` analysis system for PWR-type reactors; Um sistema de analise de ``trip`` em reatores PWR usando redes neuronais

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Antonio Carlos Pinto Dias

    1993-12-31

    The analysis short after automatic shutdown (trip) of a PWR-type nuclear reactor takes a considerable amount of time, not only because of the great number of variables involved in transients, but also the various equipment that compose a reactor of this kind. On the other hand, the transients`inter-relationship, intended to the detection of the type of the accident is an arduous task, since some of these accidents (like loss of FEEDWATER and station BLACKOUT, for example), generate transients similar in behavior (as cold leg temperature and steam generators mixture levels, for example). Also, the sequence-of-events analysis is not always sufficient for correctly pin point the causes of the trip. (author) 11 refs., 39 figs.

  15. A neural networks based ``trip`` analysis system for PWR-type reactors; Um sistema de analise de ``trip`` em reatores PWR usando redes neuronais

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Antonio Carlos Pinto Dias

    1994-12-31

    The analysis short after automatic shutdown (trip) of a PWR-type nuclear reactor takes a considerable amount of time, not only because of the great number of variables involved in transients, but also the various equipment that compose a reactor of this kind. On the other hand, the transients`inter-relationship, intended to the detection of the type of the accident is an arduous task, since some of these accidents (like loss of FEEDWATER and station BLACKOUT, for example), generate transients similar in behavior (as cold leg temperature and steam generators mixture levels, for example). Also, the sequence-of-events analysis is not always sufficient for correctly pin point the causes of the trip. (author) 11 refs., 39 figs.

  16. Priming procedure for a two-phase water thermosyphon starting from the frozen state; Procedure de demarrage d`un thermosiphon diphasique a eau a partir de l`etat gele

    Energy Technology Data Exchange (ETDEWEB)

    Sartre, V; Lallemand, M [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

    1997-12-31

    Heat pipe systems have been developed for the cooling of power electronics components used in railway applications. These systems must ensure a temperature lower than 125 deg. C at the component junctions in various functioning conditions. The aim of this work is to study the priming of a frozen water heat pipe made of 7 copper pipes with condensers connected by common flanges and cooled by forced air convection. Tests were performed under a -33 deg. C initial ambient temperature, a 5 m/s air speed and a 3 kW power. A priming procedure has been developed which allows to reach a reproducible stationary state without exceeding the maximum admissible junction temperature. This procedure consists in a delayed start-up of the ventilation system using the temperature instruction. (J.S.) 7 refs.

  17. Priming procedure for a two-phase water thermosyphon starting from the frozen state; Procedure de demarrage d`un thermosiphon diphasique a eau a partir de l`etat gele

    Energy Technology Data Exchange (ETDEWEB)

    Sartre, V.; Lallemand, M. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

    1996-12-31

    Heat pipe systems have been developed for the cooling of power electronics components used in railway applications. These systems must ensure a temperature lower than 125 deg. C at the component junctions in various functioning conditions. The aim of this work is to study the priming of a frozen water heat pipe made of 7 copper pipes with condensers connected by common flanges and cooled by forced air convection. Tests were performed under a -33 deg. C initial ambient temperature, a 5 m/s air speed and a 3 kW power. A priming procedure has been developed which allows to reach a reproducible stationary state without exceeding the maximum admissible junction temperature. This procedure consists in a delayed start-up of the ventilation system using the temperature instruction. (J.S.) 7 refs.

  18. Modeling of Transient Response of the Wickless Heat Pipes

    International Nuclear Information System (INIS)

    Hussien, A.K.A.

    2013-01-01

    Thermosyphons transient response for startup from ambient temperature to steady state until shutdown conditions, is considered a stringent necessity for applications such as electronic, solar, geothermal and even nuclear reactors safety systems. This typically returns to the need to keep the temperature within certain limits before reaching critical conditions. A simple network model is derived for describing the transient response of closed two-phase thermosyphon (CTPT) at startup and shutdown states. In addition, for predicting the effect of operational characteristics of water/copper closed two-phase thermosyphon such as thermal load, filling ratio, evaporator length, and thermosyphon tube diameter. The thermosyphons operation was considered a thermal network of various components with different thermal resistances and dynamic responses. The network model consists of six sub-models. These models are pure conduction in walls of evaporator, adiabatic and condenser, and convection in evaporator pool, evaporator film, and condenser film. So, an energy balance for each sub-model was done to estimate temperatures, heat transfer coefficients, thermal resistances, time constant, and other thermal characteristics that describe the required transient response of the closed two-phase thermosyphon. Governing equations of the transient thermosyphon behavior can be simplified into a set of first-order linear ordinary differential equations. The Runge-Kutta method can be used to obtain transient thermosyphon temperatures from these equations.

  19. Dynamical systems with classical spin in the Einstein-Maxwell-Cartan theory

    International Nuclear Information System (INIS)

    Amorin, R.M. de.

    1984-01-01

    By using variational precedures, spinning charged particles and fluids, with magnetic dipole moment, are analysed. Electromagnetic and gravitational interactions are also dynamically considered. A relativistic formalism which describes the space-time as a Riemann-Cartan manifold caraccterized by curvature and torsion tensors was adopted. The specific features of the Einstein-Maxell-Cartan theory have been analised in detail for the considered models. Also the holonomy of the local Lorentz Frames and constraints has been studied, and as a consequence it has been possible to generate new equations of motion for particles with spin. It has also been possible to derive the complete differential system which includes the fluid, the electromagnetic, the curvature and the torsion fields. (author) [pt

  20. ANALISIS METODOLÓGICO PARA LA MODELACIÓN DE LA SEGURIDAD ALIMENTARIA A NIVEL NACIONAL ANALISE METODOLÓGICO PARA A MODELAÇÃO DE A SEGURIDADE ALIMENTAR A NÍVEL NACIONAL METHODOLOGICAL ANALYSIS TO MODELING FOOD SECURITY FROM A NATIONAL PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    DIANA P GIRALDO

    2010-06-01

    Full Text Available La comunidad científica y política ha incrementado el interés por entender e intervenir el problema de seguridad alimentaria, especialmente desde la crisis alimentaria en la década de los 70's. Diferentes estrategias metodológicas han sido utilizadas con el ánimo de proyectar, predecir y evaluar políticas como soporte para la toma de decisiones en el sector público. Este artículo explora un conjunto de metodologías usadas para el estudio de la seguridad alimentaria a nivel nacional, herramientas estratégicas para una apropiada formulación, evaluación y aplicación de políticas. Se discute el potencial uso de metodologías complementarias al análisis tradicional, especialmente la Dinámica de Sistemas, como una herramienta de simulación que permite el análisis de relaciones causales, el establecimiento de variables críticas y la evaluación de escenarios a favor de una efectiva toma de decisionesA comunidade científica e política hão acrescentado o interesse por entender e intervir o problema de seguridade alimentar, especialmente, desde a crise alimentar na década dos 70's. Diferentes estratégias metodológicas hão sido utilizadas com o interesse de projetar, predizer e avaliar políticas como suportes para a toma de decisões no setor público. Este artigo explora um conjunto de metodologias empregadas no estudo da seguridade alimentar a nível nacional, ferramentas estratégicas para uma apropriada formulação, avaliação e aplicação de políticas. Discutese o potencial uso de metodologias complementárias à análise tradicional, especialmente a Dinâmica de Sistemas, como ferramentas de simulação que permite a analise de relações causais, o estabelecimento de variáveis críticas e a avaliação de cenários a favor de uma toma de decisõesThe scientific and politic community has had increasing concerns for strategic understanding and intervention of the food security problem, especially since the 70's food

  1. A compactly integrated cooling system of a combination dual 1.5-MW HTS motors for electric propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Le, T. D.; Kim, J. H.; Hyeon, C. J.; Kim, H. M.; Kim, D. K. [Jeju National University, Jeju (Korea, Republic of); Kim, Y. S. [Shin Ansan University, Ansan (Korea, Republic of); Lee, J.; Park, Y. G.; Jeon, H. [Yonsei University, Seoul (Korea, Republic of); Quach, H. L. [Electronic and Telecommunication Engineering, Can Tho University of Technology, Can Tho (Viet Nam)

    2016-12-15

    The high temperature superconducting (HTS) contra-rotating propulsion (CRP) systems comprise two coaxial propellers sited on behind the other and rotate in opposite directions. They have the hydrodynamic advantage of recovering the slipstream rotational energy which would otherwise be lost to a conventional single-screw system. However, the cooling systems used for HTS CRP system need a high cooling power enough to maintain a low temperature of 2G HTS material operating at liquid neon (LNe) temperature (24.5 - 27 K). In this paper, a single thermo-syphon cooling approach using a Gifford-McMahon (G-M) cryo-cooler is presented. First, an optimal thermal design of a 1.5 MW HTS motor was conducted varying to different types of commercial 2G HTS tapes. Then, a mono-cryogenic cooling system for an integration of two 1.5 MW HTS motors will be designed and analyzed. Finally, the 3D finite element analysis (FEA) simulation of thermal characteristics was also performed.

  2. Solar energy uses in home water heating systems; Utilizacao da energia solar em sistemas de aquecimento de agua residencial

    Energy Technology Data Exchange (ETDEWEB)

    Basso, Luiz Henrique

    2008-07-01

    The awareness of the importance of the environment has stimulated the study of new energy sources renewed and less pollutant. Amongst these sources, solar energy stands alone for being perennial and clean. The use of solar energy in systems of residential water heating, instead of the electric shower, can compliment the economy of electric energy, based on the Brazilian energy matrix. To know all the factors that influence the operation of a system of water heating by solar energy it is important the determination of its economic and technical viabilities and, distribution targeting in urban and agricultural residences. To evaluate equipment of water heating for solar energy in the region west of the Parana, Brazil, an archetype with similar characteristics to equipment used in residences for two inhabitants was built, to function with natural circulation or thermosyphon and without help of a complementary heating system. The room temperature and the speed of the wind were also evaluated, verifying its influence in the heating system. The equipment revealed technical viability, reaching the minimum temperature of 35 deg C for shower, whenever the solar radiation was above the 3500 W.m{sup -2}, for the majority of the studied days. The system operated without interruptions and it did not need maintenance, except for the monthly glass cleaning. Economic viability was clearly demonstrated since the useful life of the equipment exceeded the period of use to gain its investment. (author)

  3. Framework to development of applications to monitoring and analysis petroleum processes; Ambiente computacional para desenvolvimento de aplicacoes de monitoramento e analise de processos na industria do petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Luiz Affonso; Bezerra, Clauber; Feijo, Rafael; Eidelwein, Maria Emilia; Cunha, Dannilo Martins; Costa, Bruno [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia de Computacao e Automacao; Souza, Alessandro [Centro Federal de Educacao Tecnologica do Rio Grande do Norte (CEFET/RN), Natal, RN (Brazil)

    2008-07-01

    This paper presents a system for monitoring and visualization of plant process. The System is able to collects data from several data servers, like OPC Servers, SCADA systems and OLE DB data bases. The collected data are displayed to users using a fast human machine interface. The system has a library of software components which can be easily configured and used by users, allowing them to develop on demand their own applications. The system has other features that allow uses to easily share their applications to other users. In addition, users can access them from any computer connected to the company intranet. (author)

  4. The RAM +L analysis methodology: the refinery plants case study; Analise RAM +L: um estudo integrado de varias unidades de producao de uma refinaria

    Energy Technology Data Exchange (ETDEWEB)

    Calixto, Eduardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES); Bretas, Rogerio [PETROBRAS S.A., Betim, MG (Brazil). Refinaria Gabriel Passos (REGAP)

    2008-07-01

    The RAM (Reliability, Availability and Maintainability) main objective is assess the system and equipment performance in order to identify the critical issues to implement system's improvements. The first step is define equipment failure modes and it's PDF as well as repair time for each failure mode. The second step is modeling system regarding diagram block logic dependency among equipment and its failures which cause system production losses. The third step is simulating model in defined period of time in order to identify critical equipment to propose system improvement. Despite being having been used constantly to assess system performances, those methodology do not consider the logistic complex assumptions in so many cases to huge systems and it RDB logic do not represent the real effect in production losses. Even if that good enough to perform system analysis it's not quite enough to complex system with logistic resources regarding system's products efficiency. By the other way round, in logistic complex system analysis methodologies, equipment failures details are not regarded in so many times, showing that there's a necessary improvement in those analysis. Therefore, the RAM + L analysis is a methodology which regards all equipment failures issues as well as logistic assumptions being a more realistic analysis. The refinery case study Will be propose to demonstrate a new vision of two recognized methodologies regarding a complex system with over than 200 equipment comprising two tanks, two pumps and five Unit Plants as Vacuum Distillation, Atmospheric Distillation, Hydrogen Generation, Diesel Hydrotreating Unit and DEA. (author)

  5. Evaluation of the strengthening of the conditions of voltage security using sensitivity analysis; Avaliacao do reforco das condicoes da seguranca de tensao utilizando a analise de sensibilidade

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, A.L.S.; Costa, V.M. da; Peres, W. [Universidade Federal de Juiz de Fora (UFJF), MG (Brazil). Faculdade de Engenharia], Emails: arleilucas@gmail.com, vander@lacee.ufjf.br, wesley.peres@yahoo.com.br; Prada, R.B. [Pontificia Universidade Catolica (PUC-Rio), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Eletrica], Email: prada@ele.puc-rio.br

    2009-07-01

    Voltage stability or voltage security analysis has motivated an expressive attention of power systems researchers. In this work, a simple and fast method evaluates voltage security and proposes conditions to improve the loading margin. System analysis is carried out in terms of active power transmission path. Sensitivity analysis provides the most adequate buses to active and reactive power redispatch. A sequential iterative methodology to reinforce system conditions is presented. (author)

  6. Availability analysis of the nuclear instrumentation of a research reactor; Analise da disponibilidade da instrumentacao nuclear de um reator de pesquisa

    Energy Technology Data Exchange (ETDEWEB)

    Vianna Filho, Alfredo Marques

    2016-07-01

    The maintenance of systems and equipment is a central question related to Production Engineering. Although systems are not fully reliable, it is often necessary to minimize the failure occurrence likelihood. The failures occurrences can have disastrous consequences during a plane flight or operation of a nuclear power plant. The elaboration of a maintenance plan has as objective the prevention and recovery from system failures, increasing reliability and reducing the cost of unplanned shutdowns. It is also important to consider the issues related to organizations safety, especially those dealing with dangerous technologies. The objective of this thesis is to propose a method for maintenance analysis of a nuclear research reactor, using a socio-technical approach, and focused on existing conditions in Brazil. The research reactor studied belongs to the federal government and it is located in the city of Rio de Janeiro. The specific objective of this thesis is to develop the availability analysis of one of the principal systems of the research reactor, the nuclear instrumentation system. In this analysis, were taken into account not only the technical aspects of the modules related to nuclear instrumentation system, but also the human and organizational factors that could affect the availability of the nuclear instrumentation system. The results showed the influence of these factors on the availability of the nuclear instrumentation system. (author)

  7. Photovoltaic energy: environmental and economic analysis of axis solar trackers for photovoltaic installations; Energia fotovoltaica: analise economica ambiental de seguidores solares para instalacoes fotovoltaicas

    Energy Technology Data Exchange (ETDEWEB)

    Paes, Andrea Galvao; Bertolon, Expedito; Pacca, Sergio [Universidade de Sao Paulo (EACH/USP), SP (Brazil). Escola de Artes, Ciencias e Humanidades. Curso de Gestao Ambiental

    2008-07-01

    In this work we present an economic assessment photovoltaic systems using single axis and dual axis solar trackers. The analysis was carried out for the city of Sao Paulo and the results show that in comparison with fixed installations, the single axis system and the dual axis system produce respectively 19.6% and 24.7% more power. The power output of the dual axis system is 4.3% greater than the power output of the single axis system. Considering an annual discount rate of 12% and the equipment cost, the cost of the surplus energy due to the use of the single axis and the dual axis trackers was R$0.25/kWh and R$0.18/kWh. Because the average cost of electricity produced by photovoltaic modules is R$3/kWh, we recommend the installation of solar trackers. (author)

  8. Performance analysis of hybrid ground-coupled heat pump system with multi-functions

    International Nuclear Information System (INIS)

    You, Tian; Wang, Baolong; Wu, Wei; Shi, Wenxing; Li, Xianting

    2015-01-01

    Highlights: • The hybrid GCHP system with multi-functions is proposed. • The system maintains the soil temperature and heating reliability steady. • The multi-functional operation of HCUT can save more energy of the system. - Abstract: Underground thermal imbalance is a significant problem for ground-coupled heat pump (GCHP) systems that serve predominately heated buildings in cold regions, which extract more heat from the ground and inject less heat, especially in buildings requiring domestic hot water (DHW). To solve this problem, a previously developed heat compensation unit with thermosyphon (HCUT) is integrated with a GCHP unit to build a hybrid GCHP system. To improve the energy savings of this hybrid GCHP system, the HCUT unit is set to have multiple functions (heat compensation, direct DHW and direct space heating) in this paper. To analyze the improved system performance, a hotel requiring air-conditioning and DHW is selected and simulated in three typical cold cities using the dynamic software DeST and TRNSYS. The results indicate that the hybrid GCHP system can maintain the underground thermal balance while keeping the indoor air temperature within the design range. Furthermore, the HCUT unit efficiently reduces the energy consumption via its multi-functional operations. Compared to the previous system that only used HCUT for heat compensation, adding the direct DHW function further saves 7.5–11.0% energy in heat compensation (HC) and DHW (i.e., 3.6–4.8% of the whole system). Simultaneously adding the direct DHW and space heating functions to the HCUT can save 9.8–12.9% energy in HC and DHW (i.e., 5.1–6.0% of the whole system). The hybrid GCHP system with a multi-functional HCUT provides more energy savings while maintaining the underground thermal balance in cold regions that demand both air-conditioning and DHW

  9. An object-oriented computational model for combined cycle cogeneration analysis; Um modelo computacional para analise de ciclos combinados para projetos de sistemas de cogeracao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandre M. da; Balestieri, Jose A.P.; Magalhaes Filho, Paulo [UNESP, Guaratingueta, SP (Brazil). Escola de Engenharia. Dept. de Energia]. E-mails: amarcial@uol.com.br; perella@feg.unesp.br; pfilho@feg.unesp.br

    2000-07-01

    This paper presents the use of computational resources in a simulation procedure to predict the performance of combined cycle cogeneration systems in which energetic analysis is used in the modeling. Thermal demand of a consuming process are used as the main entrance data and, associated to the performance characteristics of each component of the system, it is evaluated the influence of some parameters of the system such as thermal efficiency and global efficiency. The computational language is Visual Basic for Applications associated to an electronic sheet. Two combined cycle cogeneration schemes are pre-defined: one is composed of a gas turbine, heat recovery steam generator and a back pressure steam turbine with one extraction, in which both are connected to the different pressure level process plant; the other scheme has a difference a two extraction-condensing steam turbine instead of the back pressure one. Some illustrative graphics are generated for allowing comparison of the appraised systems. The strategy of the system simulation is obtained by carefully linking the information of various components according to the flow diagrams. (author)

  10. Experimental evaluation of desuperheating and oil cooling process through liquid injection in two-staged ammonia refrigeration systems with screw compressors

    International Nuclear Information System (INIS)

    Zlatanović, Ivan; Rudonja, Nedžad

    2012-01-01

    This paper examines the problem of achieving desuperheating through liquid injection in two-staged refrigeration systems based on screw compressors. The oil cooling process by refrigerant injection is also included. The basic thermodynamic principles of desuperheating and compressor cooling as well as short comparison with traditional method with a thermosyphon system have also been presented. Finally, the collected data referring to a big refrigeration plant are analyzed in the paper. Specific ammonia system concept applied in this refrigeration plant has demonstrated its advantages and disadvantages. - Highlights: ► An experiment was setup during a frozen food factory refrigeration system reconstruction and adaptation. ► Desuperheating and low-stage compressors oil cooling process were investigated. ► Efficiency of compression process and high-stage compressors functioning were examined. ► Evaporation temperature reduction has great influence on the need for injected liquid refrigerant. ► Several cases in which desuperheating and oil cooling process application are justified were determined.

  11. Exergetic analysis of a gas turbine plant with chemical recuperation; Analise exergetica de uma planta de turbina a gas com recuperacao quimica

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, Mario G. Sanchez; Nebra, Silvia Azucena; Gallo, Waldir L. Ribeiro [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: 192572rg@discovery.fem.unicamp.br; sanebra@fem.unicamp.br; wgallo@fem.unicamp.br

    2000-07-01

    One of the proposals that has been more recently analyzed with growing interest in Gas Turbine cycles, with the purpose of obtaining gains in the power output and thermal efficiency, is the Chemically Recuperated Gas Turbine Cycle, (CRGT). Such systems are equipped of chemical heat recovery components in which the waste heat in the turbine exhaust is used to convert a methane-steam mixture into a hydrogen-rich fuel in a methane steam reformer. One additional aspect of these cycles that represents a potential benefit is explained by the ultra-low NO{sub x} emission levels, even less than those system which use steam injection This paper, with the aid of the concepts emanated from the Second Thermodynamic Law, is presenting an evaluation of the exergetic performance of one installation of this type. Exergetic efficiencies are evaluated according to the relation fuel-product, considering one control volume for each component of the system. (author)

  12. Thermoeconomic and exegetic analysis of a cogeneration proposal by using natural gas in breweries; Analise termoeconomica e exergetica de uma proposta de cogeracao usando gas natural em cervejarias

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, Antonio Garrido; Martins, Gilberto [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara do Oeste, SP (Brazil). Faculdade de Engenharia Mecanica e de Producao]. E-mail: agallego@unimep.br; gmartins@unimep.br; Nebra, Silvia Azucena [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica]. E-mail: sanebra@fem.unicamp.br

    2000-07-01

    In this work the thermo economic method is used for analysis of the cost distribution in a cogeneration power plant proposed for a brewery in the Campinas - state of Sao Paulo, Brazil. The thermal process energy demands were considered for beer production in 1997. The proposed cogeneration system consists of two gas turbines with recovering boiler and ammonium compression cooling system. The present power generation configuration and the cogeneration proposed performance were simulated in a monthly basis, considering the month steam and refrigeration requests. The gas turbines were simulated considering the nominal load and the energy surplus sold to the concessionaire.

  13. Energy, industrialization and exportation: analysis of the metallurgy, paper and cellulose sectors; Energia, industrializacao e exportacoes: analise dos ramos metalurgico e papel e celulose

    Energy Technology Data Exchange (ETDEWEB)

    Berni, Mauro D.

    1993-01-01

    This work discusses the energetic issue in the Brazilian industrial area, taking into consideration historical, socio, economic, and environmental aspects. An important emphasis is given to the fact that the country accepted the installation of energy-intensive and environmentally damaging industries from developed countries, and its consequences in the Brazilian energetic system. 31 refs., 48 figs., 78 tabs.

  14. Application of artificial intelligence to electrofacies identification: neural networks versus discriminant analysis; Aplicacao de inteligencia artificial na identificacao de eletrofacies redes neuroniais versus analise discriminante

    Energy Technology Data Exchange (ETDEWEB)

    Silva Rodrigues, F da [PETROBRAS, Rio de Janeiro, RJ (Brazil); Queiroz Neto, I.A. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1992-07-01

    Electro-facies are identified by neural network trained with well log and core data. Differences between neural network and expert system are discussed. According the author, the combination of neural network computing and traditional computing methods, like discriminant analysis, can help in the solution of many problems in electro-facies identification. 5 figs., 1 tab., 11 refs.

  15. Steel catenary riser design based on coupled analysis methodology; Projeto de um riser rigido em catenaria baseado em metodologia de analise acoplada

    Energy Technology Data Exchange (ETDEWEB)

    Bahiense, Rodrigo A.; Rodrigues, Marcos V. [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Due to adoption of oil and gas production systems to deep and ultra-deep water, achieving frontiers that were not conceivable before, research in computational methods has contributed to implementation of sophisticated and efficient numerical tools in order to perform simulations considering those operational conditions. Thus, this work presents a steel catenary riser (SCR) design which is connected to a semi-submersible platform where the applied motions to SCR are obtained from analyses based on de-coupled and coupled methodologies. With increase of the line number of the system and water depth, the effects due to coupling of the lines on the platform motions are significant. It can be observed from performed evaluations for a floating production system, comparing the obtained results for SCR under extreme and fatigue conditions when it was submitted to the platform motions considering both methodologies mentioned. So, from the results obtained it can be concluded that for production system evaluated the adoption of decoupled methodology presents more conservative results. Thus the adoption of the coupled model associated to design practice of production lines presents as an alternative more realist and accurate to provide the optimization in the design of these structures. (author)

  16. REXS : A financial risk diagnostic expert system

    Directory of Open Access Journals (Sweden)

    W. Richter

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Artificial intelligence techniques are rapidly emerging as important contributors to more effective management. One of the greatest growth areas probably lies in the use of Expert System methodology for supporting managerial decision processes.
    Existing Decision Support Systems often attempt to apply analytical techniques in combination with traditional data access and retrieval functions. One of the problems usually encountered while developing such decision support systems is the need to transform an unstructured problem environment into a structured analytical model. Using an expert system approach to strategic decision making in such unstructured problem environments may provide significant advantages.
    The financial Risk diagnostic EXpert System (REXS concentrates on Financial Risk Analysis. Based on a Forecasting Model the system will, with the support of several expert system knowledge bases, attempt to evaluate the financial risk of a business and provide guidelines for improvement.

    AFRIKAANSE OPSOMMING: Tegnieke gebaseer op Kunsmatige Intelligensie toon tans die belofte om belangrike bydraes te maak tot meerBestaande Besluitsteunstelsels poog dikwels om analitiese tegnieke en lradisionele datatoegang- en onttrekkingsfunksies te kombineer. Een van die probleme wat gewoonlik ondervind word gedurende die ontwikkeling van '0 besluitsteunstelsel bestaan uit die behoefte om 'n ongestruktueerde probleemomgewing te transformeer na 'n gestruktueerde analitiese model. 'n Ekspertstelselbenadering lot strategiese besluitneming in 'n ongeSlruktureerde probleemomgewing mag betekenisvolle voordele inhou.
    Die "financial Risk diagnostic EXpert System (REXS" konsentreer op fmansiele risiko-analise. Uitgaande vanaf 'n Vooruitskattingsmode~ en deur gebruik te maak van verskeie ekspertstelselkennisbasisse, poog die stelsel om die fmansiele risiko van 'n onderneming te evalueer en riglyne vir moontlike verbetering

  17. Energy conservation analysis using Fuzzy logic considering technical and environmental aspects; Analise da conservacao de energia utilizando logica fuzzy considerando aspectos tecnicos e o meio ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Jamil; Yamachita, Roberto Akira; Guardia, Eduardo Crestana [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Centro de Excelencia em Eficiencia Energetica; Reis, Alexandre de Souza Rodrigues dos; Pinto, Luiz Fernando do Monte [Furnas Centrais Eletricas, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This article presents the results obtained in the Project of Research and Development of Furnas Centrais Eletricas, which was accomplished with the partnership of the Fundacao de Pesquisa e Assessoramento a Industria - FUPAI. This project analyzed technically and economically the pollution caused in the electric net by the use, in growing scale, of nonlinear loads, such as: compact fluorescent lamps, microwave ovens, VHS systems, DVD, sound systems, etc. It was also analyzed the environmental impact caused by these lamps due to the presence of the mercury; and as complement to the traditional theory of economical analysis, a tool of economical analysis was developed using the theory of fuzzy sets for the uncertainty variables or of difficult quantification. (author)

  18. Availability analysis of high voltage substations considering its main equipment; Analise de disponibilidade de subestacoes de alta tensao considerando seus principais equipamentos

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.C. [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)], E-mail: ricardo.santos@ufabc.edu.br; Basseto, B.A.; Cugnasca, P.S.; Almeida Junior, J.R.; Camargo Junior, J.B. [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica], Emails: ricardo.santos@ufabc.edu.br, joao.camargo@poli.usp.br

    2009-07-01

    This paper evaluates the availability of electric power substations, based on Monte Carlo simulation and Fault Tree Analysis, which can be used in a larger way, considering various scenarios, usually founded. The main fallouts modes considered in the availability analysis of power systems, as well as the main methods applied to reach this goal are discussed. The availability indexes of the Monte Carlos simulation are sufficient to indicate the critical points of the power system, and to make comparisons between different substations, related to the performance levels. Through these indexes it is possible to evaluate the impact of a switching action in a determined substation. For this, the substation studied indexes are compared before and after the switching action be considered to the substation in reference.

  19. Integral analysis of the drill string dynamic behaviour to optimize drilling operation; Analise integrada do comportamento dinamico da coluna para otimizacao de perfuracao

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Araken [Smith International do Brasil, Macae, RJ (Brazil); Placido, Joao C.R.; Percy, Joseir G.; Falcao, Jose; Freire, Helena; Ono, Eduardo H.; Masculo, Miguel S. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Azuaga, Denise; Frenzel, Mark [Smith International Inc., Houston, TX (United States)

    2008-07-01

    For a performance preview of a drilling system is necessary a dynamic and integrated modeling for understanding all system forces resulting from the combination of the rock strength, cut structure action, drilling parameters, BHA and all others drilling components. This study must predict, for the drill string, vibrations and torsions, from bit to surface, its origins and its effects, and provides the best way to reduce these vibrations, determining the best bit, BHA and drilling parameters. Thereby, this study eliminates the trial and error approach and the operation risks. This paper aims to present studies of optimization for two drilling wells conducted in Brazil, one in Santos Basin and other in Campos Basin, and compares the numerical simulations results with the data from drilling operations. (author)

  20. Storage analysis of steel pipes used in pipelines; Analise do sistema de estocagem de tubos de aco para dutos de transporte

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Carlos E.C.; Silva, Breno S.; Fernandes, Lincoln F.; Santos Junior, Sergio J.F. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Louzada, Carlos H.C.M.

    2005-07-01

    New pipelines, request the use of great amount of tubes stored during its construction. Therefore, the cost generated by the storage areas motivates the reconsideration of the stockpiling system. Large areas demand high costs related to its acquisition or rent. The use of small areas can reduce the immediate cost with rent, but also can increase the total cost due to damage of the tubes or increase the risk at the storage conditions. The same considerations could be made for inadequate use of support materials on the stockpiling piles, regarding the quality or amount used. This work presents the modelling of the pyramidal stockpiling system of steel tubes and evaluations to a better configuration. (author)

  1. Performance analysis of the PLC (Power Line Communication) in medium voltage electrical networks; Analise de desempenho de sistemas PLC em redes eletricas de media tensao

    Energy Technology Data Exchange (ETDEWEB)

    Mota, A.A.; Paleta, R. [Pontificia Universidade Catolica de Campinas (PUC-Campinas), SP (Brazil)], E-mail: amota@puc-campinas.edu.br; Mota, L.T.M.; Ricardo, R.A. [Indelmatec Engenharia, Campinas, SP (Brazil)], E-mail: mota@indelmatec.com.br

    2009-07-01

    Nowadays, the information access in communication networks is widely explored due to the increase of Internet users. In this context, the PLC (Power Line Communication) technology is an alternative for data transmission. This technology is based on the usage of transmission/distribution power lines for data transmission. However there are some problems related to the usage of this technology: adequate data transmission rates and generation of acceptable levels of electromagnetic interference (EMI). This work had the objective of studying the performance of PLC systems in medium voltage electrical networks, through the assess of data transmission rates and the generated EMI. Tests were carried out in a test field that corresponded to a medium voltage electrical network and the obtained results show that, under some circumstances, the PLC system does not reach the existent technical recommendations. (author)

  2. Tax effect of the concession agreement, production sharing agreement and service contract; Analise dos efeitos tributarios dos contratos de concessao, partilha de producao e servicos

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Rodrigo Jacobina [Escola de Magistratura do Tribunal de Justica do Estado do Rio de Janeiro (EMERJ), RJ (Brazil); Instituicao de Ensino Superior no Estado do Rio de Janeiro, RJ (Brazil); Escritorio Doria, Jacobina, Rosado e Gondinho Advogados Associados, Rio de Janeiro, RJ (Brazil). Area de Direito Tributario

    2008-07-01

    The different nature of the E and P agreements recommends an analysis of the tax incidence in order to avoid the increasing of costs due to an inaccurate taxation process. The revenue obtained from Services Agreements must be, under the Brazilian legal system, taxed as the revenues obtained from the Concession Agreements, since those revenues are related to the risks supported, the investments and financial exposure, among others elements and not related to a specific public service provided. (author)

  3. Analysis of energy culture the Crambe (Crambe abyssinica Hochst) produced in no tillage; Analise energetica da cultura do Crambe (Crambe abyssinica Hochst) produzida em plantio direto

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, Samir Paulo; Biaggioni, Marco Antonio Martin; Silva, Paulo Roberto Arbex; Seki, Andre Satoshi; Bueno, Osmar Carvalho de [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas], E-mail: jasper@fca.unesp.br

    2010-07-01

    The objective of this study was to characterize the energy consumption in the deployment and conduct of the culture of Crambe abyssinica Hochst in no-tillage, at the Experimental Farm Farm belonging to the Faculty of Agronomic Sciences - UNESP, located in Botucatu - SP. Assessing the sustainability of the system were estimated, energy efficiency and culture of crambe. To survey the components of the structure of expenditures, we used coefficients Energetic in specialized literature. The structures of energy expenditure by type, source and form, demonstrated that the indirect energy participated with 65.03%, industrial sources, fossil and biological accounted for 68.80%, 23.67% and 11.30%, respectively. The forms have been introduced; chemical fertilizers contributed 44.31% and diesel to 23.04% to 67.35% of energy expenditure, showing the dependence of the system of energy sources and industrial fuels. The efficiency of the culture was found to be 9.98, indicating that for each calorie used in the production of crambe return was 8.98 units, the efficiency was above 38, demonstrating the high sustainability of the agricultural system to reach energy cultural exceeding 37 thousand MJ ha{sup -1}. (author)

  4. The energy rational and alternative sources use at USP: results analysis; O uso racional de energia e fontes alternatives na USP: analise de resultados

    Energy Technology Data Exchange (ETDEWEB)

    Saidel, Marco Antonio; Gimenes, Andre Luiz Veiga; Castello Branco, Paula Luiz [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia de Energia e Automacao Eletricas. Grupo de Energia]. E-mails: saidel@pea.usp.br; gimenes@gmail.com; paulacastello@pea.usp.br

    2006-07-01

    This paper presents results from the PUREFA - Programa de Uso Racional de Energia e Fontes Alternativas da Universidade de Sao Paulo -, in accordance with actions originated on the 13 physical goals and respective impacts for the University. The actions comprehend: the extension of the distributed energy generation of USP through implantation of 9 kWp photovoltaic and 15 kW of biogas generation; implantation of permanent incentives to the efficient and rational use of energy; creation of regulations for the energy efficiency on buildings; replacement of public and internal lighting systems and air-conditioning; installation of solar heating systems at Sao Carlos, Piracicaba and Sao Paulo, replacing the electric shower; installation of water heating solar system at central restaurant at campus CUASO, at Sao Paulo. The results show the importance of destination resources for the energy efficiency of public sector, the fast return of the investments performed and the potentialization capacity and the dissemination of that actions when applied to the University.

  5. Heat-Pipe-Associated Localized Thermoelectric Power Generation System

    Science.gov (United States)

    Kim, Pan-Jo; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Jang, Ju-Chan; Lee, Wook-Hyun; Lee, Ki-Woo

    2014-06-01

    The present study focused on how to improve the maximum power output of a thermoelectric generator (TEG) system and move heat to any suitable space using a TEG associated with a loop thermosyphon (loop-type heat pipe). An experimental study was carried out to investigate the power output, the temperature difference of the thermoelectric module (TEM), and the heat transfer performance associated with the characteristic of the researched heat pipe. Currently, internal combustion engines lose more than 35% of their fuel energy as recyclable heat in the exhaust gas, but it is not easy to recycle waste heat using TEGs because of the limited space in vehicles. There are various advantages to use of TEGs over other power sources, such as the absence of moving parts, a long lifetime, and a compact system configuration. The present study presents a novel TEG concept to transfer heat from the heat source to the sink. This technology can transfer waste heat to any location. This simple and novel design for a TEG can be applied to future hybrid cars. The present TEG system with a heat pipe can transfer heat and generate power of around 1.8 V with T TEM = 58°C. The heat transfer performance of a loop-type heat pipe with various working fluids was investigated, with water at high heat flux (90 W) and 0.05% TiO2 nanofluid at low heat flux (30 W to 70 W) showing the best performance in terms of power generation. The heat pipe can transfer the heat to any location where the TEM is installed.

  6. Sensitivity analysis for heat diffusion in a fin on a nuclear fuel element; Analise de sensitividade na difusao de calor em uma aleta de um elemento combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Tito, Max Werner de Carvalho

    2001-11-15

    The modern thermal systems generally present a growing complexity, as is in the case of nuclear power plants. It seems that is necessary the use of complex computation and mathematical tools in order to increase the efficiency of the operations, reduce costs and maximize profits while maintaining the integrity of its components. The use of sensitivity calculations plays an important role in this process providing relevant information regarding the resultant influence of variation or perturbation of its parameters as the system works. This technique is better known as sensitivity analysis and through its use makes possible the understanding of the effects of the parameters, which are fundamental for the project preparation, and for the development of preventive and corrective handling measurements of many pieces of equipment of modern engineering. The sensitivity calculation methodology is based generally on the response surface technique (graphic description of the functions of interest based in the results obtained from the system parameter variation). This method presents a lot of disadvantages and sometimes is even impracticable since many parameters can cause alterations or perturbations to the system and the model to analyse it can be very complex as well. The utilization of perturbative methods result appropriate as a practical solution to this problem especially in the presence of complex equations. Also it reduces the resultant computational calculus time considerably. The use of these methods becomes an essential tool to simplify the sensitivity analysis. In this dissertation, the differential perturbative method is applied in a heat conduction problem within a thermal system, made up of a one-dimensional circumferential fin on a nuclear fuel element. The fins are used to extend the thermal surfaces where convection occurs; thus increasing the heat transfer to many thermal pieces of equipment in order to obtain better results. The finned claddings are

  7. Analysis of nitrogen injection as alternative fluid to steam in heavy oil reservoir; Analise da injecao de nitrogenio como fluido alternativo ao vapor em reservatorio de oleo pesado

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Marcos Allyson Felipe; Galvao, Edney Rafael Viana Pinheiro; Barillas, Jennys Lourdes; Mata, Wilson da; Dutra Junior, Tarcilio Viana [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2012-07-01

    Many of hydrocarbon reserves existing in the world are formed by heavy oils (deg API between 10 and 20). Moreover, several heavy oil fields are mature and, thus, offer great challenges for oil industry. Among the thermal methods used to recover these resources, steam flooding has been the main economically viable alternative. Latent heat carried by steam heats the reservoir, reducing oil viscosity and facilitating the production. This method has many variations and has been studied both theoretically and experimentally (in pilot projects and in full field applications). In order to increase oil recovery and reduce steam injection costs, the injection of alternative fluid has been used on three main ways: alternately, co-injected with steam and after steam injection interruption. The main objective of these injection systems is to reduce the amount of heat supplied to the reservoir, using cheaper fluids and maintaining the same oil production levels. In this paper, the use of N{sub 2} as an alternative fluid to the steam was investigated. The analyzed parameters were oil recoveries and net cumulative oil productions. The reservoir simulation model corresponds to an oil reservoir of 100 m x 100 m x 28 m size, on a Cartesian coordinates system (x, y and z directions). It is a semi synthetic model with some reservoir data similar to those found in Potiguar Basin, Brazil. All studied cases were done using the simulator STARS from CMG (Computer Modelling Group, version 2009.10). It was found that N{sub 2} injection after steam injection interruption achieved the highest net cumulative oil compared to others injection system. Moreover, it was observed that N2 as alternative fluid to steam did not present increase on oil recovery. (author)

  8. Mechanical analyses of pipeline repair and reinforcement with use of composite functionally graded materials; Analise mecanica de reforco de dutos submarinos com materiais compositos com gradacao funcional

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Marcos S.M. [Sondotecnica Engenharia de Solos S.A., Rio de Janeiro, RJ (Brazil); Roehl, Deane de Mesquita [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2008-07-01

    This work presents a methodology for design of stiffener sleeve constituted by functionally graded composite materials in offshore pipelines located in extreme-deep waters, where high mechanical resistance allied to an efficient system of thermal isolation is necessary, in view of the excellent thermomechanical behavior of composites. For the case of FGMs, due to continuous variation in its featuring, is necessary to employ an adapted model, based on a model typically adopted for conventional composites (Rule of Mixture), as the model idealized by Tamura, Tomato e Ozawa, the TTO model. In this report, the influence of geometric and materials parameters in mechanical behavior of pipelines under propagating collapse is analyzed. (author)

  9. A case study on riser analysis of a drilling riser in deep waters; Estudo de caso: analises estruturais e hidrodinamicas de um riser de perfuracao em aguas profundas

    Energy Technology Data Exchange (ETDEWEB)

    Roveri, Francisco E.; Pestana, Rafael G. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2008-07-01

    This paper presents a set of structural and hydrodynamic analyses of a connected marine riser, in 1900 meter water depth. Operating windows are determined for one year return period environmental conditions and for a set of drilling fluid weight density values. Parametric analyses are carried out to study the riser response sensitivity to variations in environmental conditions, drilling fluid weight density, upper and lower flex joint rotational stiffness and vessel motion phase angles. Current, drilling fluid weight density and vessel motion phase angle changes affect significantly the system response, whereas the response is not significantly affected by changes in wave height, wave period and flex joint rotational stiffness. (author)

  10. Pre-salt new regulatory mark and the economic order: constitutionality analysis; Novo marco regulatorio do pre-sal e a ordem economica: analise de constitucionalidade

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Marcela Brasil Pedrosa; Araujo, Mayara de Carvalho; Xavier, Yanko Marcius; Guimaraes, Patricia Borba Vilar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2010-07-01

    The discovery of vast reserves of hydrocarbons in the pre-salt layer that extends from Espirito Santo to Santa Catarina, added with the economic and strategic value of oil and natural gas, has brought discussion about the reasonableness of the regulatory model adopted so far. Would be prudent to explore these resources through the concession model? From detailed analysis of the doctrinal and bills that aim to inaugurate the new regulatory bills, we sought to answer this question, based majorly on the principles of economic activity applied in our constitutional system. Motivated by the analysis of these constitutional principles proposed, the State is seen as a regulating agent of the economic activities, fulfilling its role to supervise, encourage and plan the direction of national economic system. The sharing model gives greater state involvement and is able to convert the wealth of pre-salt in citizenship, but only if well implemented. Thus, based on constitutional principles and the notion of development as freedom, the conclusion of this paperwork is for the constitutionality of the new regulatory bills. (author)

  11. Experimental analysis of minimum shear stress to drag particles in a horizontal bed; Analise experimental da tensao de cisalhamento minima para arraste de particulas em um leito horizontal

    Energy Technology Data Exchange (ETDEWEB)

    Dornelas, Breno Almeida; Soares, Edson Jose [Universidade Federal do Espirito Santo. Departamento de Engenharia Mecanica (Brazil)], e-mails: bad@ucl.br, edson@ct.ufes.br; Quirino Filho, Joao Pedro; Loureiro, Bruno Venturini [Faculdade do Centro Leste (UCL). Laboratorio de Fluidos e Fenomenos de Transporte (Brazil)], e-mails: joaoquirino@ucl.br, brunovl@ucl.br

    2009-12-15

    Efficient hole cleaning is still a challenge in well bore drilling to produce oil and gas. The critical point is the horizontal drilling that inherently tends to form a bed of sediment particles at the well bottom during drilling. The cuttings bed erosion depends mainly on the shear stress promoted by the drilling fluid flow. The shear stress required to cause drag in the cuttings bed is investigated according to the fluid and particles properties, using an experimental assembly, composed of: a system for fluid circulation, a particle box, a pump system and measuring equipment. The observation area is a box below the flow line in an acrylic duct used to calibrate sand particles. The test starts with the pumps in a low frequency which is increased in steps. At each frequency level, images are captured of carried particles and the established flow rate is recorded. The images are analyzed when the dragged particle is no longer random and sporadic, but becomes permanent. The shear stress is identified by the PKN correlation (by Prandtl, von Karman, and Nikuradse) for the minimum flow rate necessary to cause drag. Results were obtained for just water and water-glycerin solution flows. (author)

  12. Critical analysis in the inventories of methane in oil and gas industry; Analise critica de inventarios de metano na industria do oleo e gas

    Energy Technology Data Exchange (ETDEWEB)

    Schmall, Vicente; Montez, Edson [PETROBRAS, Sao Luiz, MA (Brazil). Seguranca, Meio Ambiente e Saude; Rosa, Ana Regina [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    The methane contribution arising from anthropogenic activities plays a role of great significance when elevating the concentration of gases of greenhouse effect found in the atmosphere. The methane presents a global warming potential twenty one times higher than the carbon dioxide and its atmospheric lifespan is lower than the other gases of greenhouse effect. Its control is regarded as being one of the most efficient ways to mitigate the global climate changes in the short term, which requires previous quantification of its emissions. PETROBRAS, aiming at achieving its environmental excellence, is implementing a system of management and inventory of gases emission into the atmosphere. The emissions inventory of 2003, published in its Social Sustainability Report appears as a result of this effort. This paper presents a comparison between the results generated by the PETROBRAS' Management and Inventory of Emissions System and those deriving from the application of the methodology suggested by the Intergovernmental Panel on Climate Change (IPCC). The impact of the chosen methodology, the aggregation level and the data availability of the emission sources on the results obtained are highlighted. (author)

  13. Probabilistic risk analysis of casing drilling operation for an onshore Brazilian well; Analise probabilistica de risco de uma operacao de casing drilling para um poco terrestre no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Jacinto, Carlos M.C.; Petersen, Flavia C.; Placido, Joao C.R. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Garcia, Pauli A.A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2008-07-01

    In the present paper, one presents an approach to hazard identification and risks quantification concerning the use of retrievable BHA, of a casing drilling system, in 12 1/4 phase of an onshore well. The adopted approach can be subdivided as: execution of a hazard and operability study; prioritization of critical deviance; modeling of critical deviance by mean of event sequence diagram, fault tree and Bayesian network; modeling and simulation of a dynamic decision tree and experts' opinion analysis. As results, one has obtained: the time distribution to achieve the different ends modeled in the decision tree, i.e., sidetrack, or operation canceling, or success; the probabilities to achieve each modeled end and all recommendation to improve the success probability. The approach proved to be efficient in order that it presents significant results to support the decisions involving the casing drilling operations. (author)

  14. Failure data specialization in quantitative risk assessments of process plants; Especializacao de dados de falha em analise quantitativa de riscos de plantas de processo

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Antonio C.O. [Bayer S.A., Sao Paulo, SP (Brazil); Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2005-07-01

    The aim of this paper is to show the Bayesian inference in reliability studies, which are used to failures rates updating in safety analyses. It is developed the impact of its using in quantitative risks assessments for industrial process plants. With this approach we find a structured and auditable way of showing the difference between an industrial installation with a good project and maintenance structure from another one that shows a low level of quality in these areas. In general the evidence from failures rates and as follow the frequency of occurrence from scenarios, which the risks taken in account in ERA, are taken from generics data banks, instead of, the installation in analysis. When using the plant data we need special effort to develop a data bank, that is, a maintenance managing system, which allows the data insertion as for example the SAP{sup R} and its PM module. (author)

  15. Performance analysis of numeric solutions applied to biokinetics of radionuclides; Analise de desempenho de solucoes numericas aplicadas a biocinetica de radionuclideos

    Energy Technology Data Exchange (ETDEWEB)

    Mingatos, Danielle dos Santos; Bevilacqua, Joyce da Silva, E-mail: dani@ime.usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (IME/USP), SP (Brazil). Instituto de Matematica e Estatistica; Todo, Alberto Saburo; Rodrigues Junior, Orlando, E-mail: astodo@ipen.br, E-mail: rodrijr@ipen.br [Instituto de Pesquisas Energeticas Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Biokinetics models for radionuclides applied to dosimetry problems are constantly reviewed by ICRP. The radionuclide trajectory could be represented by compartmental models, assuming constant transfer rates between compartments. A better understanding of physiological or biochemical phenomena, improve the comprehension of radionuclide behavior in the human body and, in general, more complex compartmental models are proposed, increasing the difficulty of obtaining the analytical solution for the system of first order differential equations. Even with constant transfer rates numerical solutions must be carefully implemented because of almost singular characteristic of the matrix of coefficients. In this work we compare numerical methods with different strategies for ICRP-78 models for Thorium-228 and Uranium-234. The impact of uncertainty in the parameters of the equations is also estimated for local and global truncation errors. (author)

  16. Thermal economical analysis of plants configuration proposed for expansion of a thermoelectric power plant; Analise termoeconomica de configuracoes de plantas propostas para a expansao de uma usina termoeletrica

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Fabiano P.; Romao Junior, Ricardo A.; Mashiba, Marcos H.S.; Dib, Fernando H.; Maia, Cassio R.M.; Ramos, Ricardo A.V. [Universidade Estadual Paulista (UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia de Ilha Solteira (FEIS). Dept. de Engenharia Mecanica]. E-mails: pagliosa@dem.feis.unesp.br; fhdib@aluno.feis.unesp.br; rarjunior@aluno.feis.unesp.br; mashiba@dem.feis.unesp.br; cassio@dem.feis.unesp.br; ramos@dem.feis.unesp.br

    2006-07-01

    This paper performs thermodynamic and thermoeconomic analyses applied to a thermoelectric natural gas primarily open cycle power plant and posteriorly operating at combined cycle, with heat recovery steam generator with 1, 2 and 3 pressure level respectively. For the system thermodynamic, mass conservation, entropy and exergy balance equations are applied, considering a control volume for each equipment composing the plant. Using thermoeconomic analysis it is possible to evaluate the reflexes of the capital and fuel costs on the composition of the electricity generated, through the exergy fluxes, the exergy unitary costs and the exergoeconomic costs (US$/MWh), besides the costs for the produced powers. The plant is still submitted to known techniques of investment analysis for economical viability verification taking into account the investment and natural gas costs and the energy sales.

  17. Analysis of agricultural soils by using energy dispersive X-ray fluorescence; Analise de solos agricolas por fluorescencia de raios-X por dispersao de energia

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, Marcelino Jose dos

    2000-03-01

    In this work, we describe an Energy Dispersive x-ray Fluorescence System with a x-ray tube excitation for trace analysis of environmental samples (soil). The system was used to analyze the contamination of metals in treated soils with doses of 10, 20 and 30 ton/ha of compound organic of urban garbage of the type Fertilurb and 10 ton/ha of aviary bed (manure of birds). Samples of roots and foliages of plant radishes cultivated in these soils were also analyzed. The soil samples were collected in five different depths of 0,5, 5-10, 10-20, 20-40 and 40-60 cm. The experimental set-up is composed by an OXFORD X-ray (30 kV, 50 {mu}A and W anode), an ORTEC Si-Li detector, with an energy resolution of about 180 eV at 5.9 keV and an ORTEC multichannel-analyser. The X-ray spectrum tube is quasi-monochromatic by using of Ti filter. Samples were prepared in pellet form with superficial density in the range of 100 mg/cm{sup 2}. The fundamental parameter method was used in order to verify the elemental concentration. It was possible to determine the concentrations of thirteen elements: K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr, Y, Zr and Pb in the treated soils with compounds organic. The results indicate that the values found for K, Ca, Rb, Sr, Zr and Pb are significantly above the upper confidence limits for the control soil ({alpha} = 0.05). There is a real different between these elements compared to their relationship in the control soils, ({alpha}=0,05). There is a real difference between these elements compared to their relationship in the control soils, confirming the influence of the organic compounds in the soil. (author)

  18. Hazard analysis and critical control point to irradiated food in Brazil; Analise de perigos e pontos criticos de controle para alimentos irradiados no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Boaratti, Maria de Fatima Guerra

    2004-07-01

    Food borne diseases, in particular gastro-intestinal infections, represent a very large group of pathologies with a strong negative impact on the health of the population because of their widespread nature. Little consideration is given to such conditions due to the fact that their symptoms are often moderate and self-limiting. This has led to a general underestimation of their importance, and consequently to incorrect practices during the preparation and preservation of food, resulting in the frequent occurrence of outbreaks involving groups of varying numbers of consumers. Despite substantial efforts in the avoidance of contamination, an upward trend in the number of outbreaks of food borne illnesses caused by non-spore forming pathogenic bacteria are reported in many countries. Good hygienic practices can reduce the level of contamination but the most important pathogens cannot presently be eliminated from most farms, nor is it possible to eliminate them by primary processing, particularly from those foods which are sold raw. Several decontamination methods exist but the most versatile treatment among them is the ionizing radiation procedure. HACCP (Hazard Analysis and Critical Control Point) is a management system in which food safety is addressed through the analysis and control of biological, chemical, and physical hazards from raw material production, procurement and handling, to manufacturing, distribution and consumption of the finished product. For successful implementation of a HACCP plan, management must be strongly committed to the HACCP concept. A firm commitment to HACCP by top management provides company employees with a sense of the importance of producing safe food. At the same time, it has to be always emphasized that, like other intervention strategies, irradiation must be applied as part of a total sanitation program. The benefits of irradiation should never be considered as an excuse for poor quality or for poor handling and storage conditions

  19. Thermal study of a residential water solar heating system with two different absorbing surface configurations; Estudo termico de um sistema solar de aquecimento de agua residencial para duas configuracoes de superficie absorvedora

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Rivaldo Ferreira

    2009-10-15

    A solar collector to be used in a system for heating water for bathing, whose main characteristics are its low cost and easy manufacturing and assembly is presented. The absorbing surface of the collector is formed by an aluminum plate with eight flaps where they lodge PVC pipes. The catchment area of solar radiation corresponds to 1.3 meters. The collector box was made of wood, it is covered by transparent glass and thermal insulation of tire chips and expanded polystyrene (EPS). Absorber tubes were connected in parallel through the use of PVC fittings and fixed to the plate by the use of metal poles and rivets. The entire absorber received paint fiat black for better absorption of sunlight. The system worked on a thermosyphon assembly and absorber of the collector has been tested in two configurations: with the tubes facing up, directly exposed to the impact of sunlight and facing down, exchanging heat with the plate by conduction. The most efficient configuration for the connect purpose was determined. The solar collector was connected to a thermal reservoir, also alternative, low-cost forming the system of solar water heating. We evaluated thermal parameters that proved the viability of the heating system studied. (author)

  20. Re-potentiation of hydro-generators: a proposal of analysis and implementation methodology; Repotenciacao de hidrogeradores: uma proposta de metodologia de analise e implantacao

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Fabio Salomao Fernandes

    1996-07-01

    The hydro-generators suffer during its operative useful life a combination of stresses of nature thermal, electric, mechanics and environmental. With the time, they are going losing the capacity to support those stresses and the power plants suffer, more and more frequently, undesirable stops for repair services and maintenance. In function of the high costs incurred with these stopped, the operation of the power plant can be economically impracticable. That unavailability of the generation for the electric system, it results in reduction of the reliability, burdening the politics of load ruling. The re-potentiation is a proposal that seeks to extend the useful life of hydro-generators, at the same time that it try to rescue the reliability and the readiness of the plant, with larger power. The power increase is usually made possible, or for the surplus of the hydro resources in excess, or for the reduction of the losses of all the components of the energy flow. That work proposes a methodology structured starting from the estimate of the potential, of rising of data, of the basic project and of the executive project. Modern techniques of engineering, new processes and new materials, allow the re-potentiation of those hydro-generators returning them new useful life, under conditions economically justifiable.

  1. Appreciation of environmental risks analysis methodologies in the offshore well drilling activities; Analise de metodologias na avaliacao de riscos ambientais relacionados as atividades de perfuracao de pocos maritimos

    Energy Technology Data Exchange (ETDEWEB)

    Zampolli, Daniella M. [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil); Morooka, Celso K. [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo

    2004-07-01

    Nowadays, the projects of products and processes are supposed to integrate environmental risks criteria, in addition to their inherent operation impacts. Industrial activities, in general, generate risks to the environment, and, in case of incidents occurrence, many of the possible consequences can be translated into serious impacts. The Risk Analysis is destined to act as a decision tool in the environmental area, and therefore, the use of one of these during the project phase of an enterprise becomes important, aiming the guarantee of the system reliability. The present article has the purpose of analyzing methodologies that are being employed for the environmental risk analysis, as well as usual procedures applied in the oil industry, specially for the offshore wells drilling, evaluating and discussing their peculiarities and possible improvement. It was intended to obtain a general overview of risk analysis methodologies, with the objective of verifying the existence of some characteristics that would positively contribute for the knowledge of the inherent risks in the activities of petroleum installations, where this kind of learning is something extremely technically necessary and legally mandatory. (author)

  2. Numerical analysis of the turbulent natural convection in a solar chimney; Analise numerica da conveccao natural turbulenta em uma chamine solar

    Energy Technology Data Exchange (ETDEWEB)

    Brasil, Cristiana S.; Valle, Ramon M.; Cortez, Marcio F.B.; Ferreira, Andre G. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica]. E-mail: tite@demec.ufmg.br; ramon@demec.ufmg.br; fonteboa@demec.ufmg.br; ferreira@demec.ufmg.br

    2000-07-01

    This paper presents a theoretical analysis of the turbulent natural convection in a solar chimney operating in steady flow, with prescribed conditions of temperature in the ground. The solar radiation heats the air under the cover, which flows to the tower without artificial pumping. The hot air produced may be used to dry several agricultural products. The numerical analysis of the natural convection in this kind of dryer has fundamental importance on the design and building of this device. The mathematical model includes the conservation laws for mass, momentum and thermal energy and the transport equations for the turbulence model variables (k and e ). The k- e model of turbulence with wall functions was used. A computational code using the Finite Volume Method in Generalized Coordinates was developed to solve the system of equations that describes thermal and hydro dynamically the flow. The velocity and temperature fields are shown to the flow in the solar chimney. With geometrical alterations on the device, one can obtain a detailed description of the flow, which allow the guideline for a suitable configuration to build an experimental prototype. (author)

  3. Analysis of the zirconia structure by `ab initio` and Rietveld methods; Analise da estrutura da zirconia por metodos `Ab initio` e de Rietveld

    Energy Technology Data Exchange (ETDEWEB)

    Bechepeche, A.P.; Nasar, R.S.; Longo, E. [Sao Carlos Univ., SP (Brazil). Dept. de Quimica; Treu Junior, O.; Varela, J.A. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica

    1995-12-31

    The zirconia was doped with 0,113 mol of Mg O e 0,005 mol of Ti O{sub 2}, and it was calcined in 1550{sup d}eg C and it was analyzed by XRD. The results shows that pure zirconia contains 96,19% of monoclinic phase and 3,18% of cubic. However, the doping magnesia stabilizes the zirconia in 17,24 of monoclinic; 29,63 of tetragonal and 53,13% of cubic phase. The addition of titanium in zirconia gives 25,85% of tetragonal phase and 37,66% of cubic, and this shows the no stabilizing action of this transition metal. By the other side, the results with ab-initio calculating shows the same tendency resulting in the next values of total energy: pure zirconia - monoclinic -11.316,86ua; tetragonal -8742,09 ua and cubic -8742,80 ua and Zr O{sub 2} Ti O{sub 2} system - monoclinic -9463,02 ua, tetragonal -9459,39 ua and cubic -9459,97 ua (author) 3 figs., 2 tabs.

  4. Identification of energy gain potential in industrial processes, through exergetic analysis; Identificacao de potenciais de ganho energetico em processos industriais via analise exergetica

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Lis Nunes; Silva, Ricardo Junqueira; Bernardes, Lucas Lanza; Filgueiras, Pedro Freire [V e M do Brasil S.A., Belo Horizonte, MG (Brazil)

    2011-12-21

    V and M Brazil is an integrated steel mill for the production of steel tubes. The manufacturing process includes various processes and thermal equipment, such as industrial furnaces, boilers, and others. Due to its importance, it is essential that these devices operate with the best possible efficiency. Thus, it becomes necessary to use tools and methods for performance analysis of energy processes that occurs on these devices. One tool that has been widely used in industrial environment is the exergy analysis. It is based on the Second Law of Thermodynamics, and therefore takes into account the entropy generation, indicating the maximum amount of useful energy (work) that can be drawn from a stream, with reference to environmental parameters. This paper aims to apply the exergetic methodology in industrial thermal processes that occurs at V and M Brazil, as a tool for identification of losses and potential performance improvement of energy systems to save on fuel and the reduction of environmental impacts and emissions of greenhouse gases. (author)

  5. Optical fiber smart sensor for conformity analysis of Brazilian gasoline; Sensor inteligente a fibra otica para analise da conformidade da gosolina brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Possetti, Gustavo R.C.; Camilotti, Emmanuelle; Arruda, Lucia V.R. de; Muller, Marcia; Fabris, Jose L. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Cocco, Lilian C.; Yamamoto, Carlos I. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Falate, Rosane [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil)

    2008-07-01

    The conventional techniques employed to monitor the gasoline quality are expensive, time-consuming and demands on specialized workers to its execution. A study about the applicability of a long period grating, a fiber optic device, as an auxiliary tool for the analysis of Brazilian gasoline conformity is presented in this work. The long period grating spectral response was measured with the device immersed in samples of gasoline A with different proportions of hydrated ethyl alcohol fuel. A resolution of 0.23 % was obtained for the concentrations range of commercial interest, between 20 % and 40 %. The device performance was also tested with a set of conform and non-conform gasoline C samples. The device spectral response for these samples, as well as the samples densities and the conformity status were employed to train and to validate an artificial neural network with radial base function. The obtained results show that fiber optic sensors supervised by artificial neural networks can constitute systems for smart measurement with high applicability in the analyses of gasoline conformity, reducing costs and time related to conventional tests. (author)

  6. Economic and financial feasibility analysis of natural gas urban distribution; Analise da viabilidade economica e financeira para o desenvolvimento da rede urbana de distribuicao de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Guilherme G.; Cunha, Eduardo N.; Teixeira, Clovis C. [Companhia de Gas do Estado do RS (SULGAS), Porto Alegre, RS (Brazil)

    2008-07-01

    SULGAS has developed more judicious systematics investments analysis in the natural gas distribution plants in urban areas . A survey has been made of the variables that influence this type of investment, identifying the most relevant ones. Spread sheet in platform Microsoft Excel and Visual Basic was elaborated that makes possible the deterministic analysis, sensibility, and risk analysis of the projects, through consolidated indicators usable in economic engineering. The great differentiation of this proposal is the possibility/flexibility of the economic impact analysis that each future customer has in the branch where he is linked. The spread sheet presents graphical platforms in which the schematical drawings of the projects are inserted on satellite photos of the region, making possible the projects architectures visualization in parallel with the economic analysis. This graphical platform is tied with the alternatives selected in the economic analysis, being brought up to date the images in accordance with the projects selected in the spread sheet. The risk analysis are carried out through the Monte Carlo simulation, generating investment return probability from each branch, cell, or customer, depending on the criteria defined in the spread sheet. This makes possible the insertion and economic analysis of the factors that can influence the investments in NG distribution system, becoming an important tool in the decision making. (author)

  7. Thermo-fluid analysis of water cooled research reactors in natural convection; Analise termofluidodinamica de reatores nucleares de pesquisa refrigerados a agua em regime de conveccao natural

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Maria Auxiliadora Fortini

    2004-07-01

    The STHIRP-1 computer program, which fundamentals are described in this work, uses the principles of the subchannels analysis and has the capacity to simulate, under steady state and transient conditions, the thermal and hydraulic phenomena which occur inside the core of a water-refrigerated research reactor under a natural convection regime. The models and empirical correlations necessary to describe the flow phenomena which can not be described by theoretical relations were selected according to the characteristics of the reactor operation. Although the primary objective is the calculation of research reactors, the formulation used to describe the fluid flow and the thermal conduction in the heater elements is sufficiently generalized to extend the use of the program for applications in power reactors and other thermal systems with the same features represented by the program formulations. To demonstrate the analytical capacity of STHIRP-l, there were made comparisons between the results calculated and measured in the research reactor TRIGA IPR-R1 of CDTN/CNEN. The comparisons indicate that the program reproduces the experimental data with good precision. Nevertheless, in the future there must be used more consistent experimental data to corroborate the validation of the program. (author)

  8. Quantitative analysis of properties of petroleum mixtures by near infrared spectroscopy; Analise quantitativa de propriedades de misturas de petroleos via espectrofotometria no infravermelho proximo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Leila M.; Silva, Elisangela B.; Fortuny, Montserrat; Dariva, Claudio; Santos, Alexandre F. [Universidade Tiradentes (UNIT), Aracaju, SE (Brazil). Instituto de Tecnologia e Pesquisa (ITP); Araujo, Augusto M. [Siemens Brazil, Rio de Janeiro, RJ (Brazil); Coutinho, Raquel C.C. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    An experimental study is carried out aiming to develop a method of quantitative analysis of properties of petroleum mixtures, such as water and asphaltene contents, heavy oil concentration and viscosity based on the use of a NIR spectrophotometer. A strategy of generation of crude oil mixtures with known properties was developed to help calibrating the NIR spectrophotometer. Petroleum mixtures involving 2 or 3 oils under known ratios were prepared based on a set of different light and heavy Brazilian crude oil samples. Moreover, experimental data of 5 binary mixtures were also assembled into a data set named multi-compound. Results indicated that excellent calibration models can be obtained for binary mixtures with correlation coefficient (R{sup 2}) greater than 99% for water and asphaltene contents, viscosity and heavy oil concentration. For ternary systems, excellent correlations (R{sup 2}>99%) can be attained for asphaltene and heavy oil contents. Finally for the multi-compound data set, the asphaltene content was the only property that resulted in R{sup 2}>99%, which demonstrates the adequacy of the NIR technique for assessing this property. (author)

  9. Numerical analysis of the fluid dynamics in a natural circulation loop; Analise numerica da dinamica do escoamento em circuitos de circulacao natural

    Energy Technology Data Exchange (ETDEWEB)

    Angelo, Gabriel

    2013-07-01

    Natural circulation loops apply to many engineering applications such as: water heating solar energy system (thermo-siphons), thermal management of electrical components (voltage converter), geothermal energy, nuclear reactors, etc. In pressurized water nuclear reactors, known as PWR's, the natural circulation loops are employed to ensure passive safety. In critical situations, the heat transfer will occur only by natural convection, without any external control or mechanical devices. This feature is desired and has been considered in modern nuclear reactor projects. This work consists of a numerical study of the natural circulation loop, located at the Instituto de Pesquisas Energeticas e Nucleares / Comissao Nacional de Energia Nuclear in Sao Paulo, Brazil, in order to establish the flow pattern in single phase conditions. The comparison of numerical results to experiments in transient condition revealed significant deviations for the Zero Equation turbulence model. Intermediate deviations for the Eddy Viscosity Turbulence Equation (EVTE), k - {omega}, SST e SSG models. And the best results are obtained by the k - {epsilon} e DES models (with better results for the k - {epsilon} model). (author)

  10. Comparative analysis of national and state publications on the quality control of radiation diagnosis; Analise comparativa das publicacoes nacionais e estaduais de controle de qualidade em radiodiagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Michel F.F.; Souza, Danilo L.M.; Oliveira, Caio V.; Cabete, Henrique V.; Cruz, Livia C.; Pires, Silvio R.; Freitas, Marcelo B.; Medeiros, Regina B. [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina

    2016-07-01

    Taking into account that there are several standards for Quality Control in diagnostic radiology, the purpose of this research was to carry out an overview of Brazilian regulatory publications. The sample was composed by Ordinance 453/98, resolutions SS-625 (SP), SES/MG Number 5177, 002/DIVS/SES (SC) and ANVISA guide. Differences and similarities in the tests, nomenclatures, periodicity and performance parameters were evaluated. It was identified that SS-625 was one of the first publications in the area, proposing standards and indicating reference levels. ANVISA guide describes the procedures for performing the tests established in Ordinance 453. The 002/DIVS/SES included digital imaging systems and provides more restrictive performance standards in some tests when compared other publications. ES/MG Number 5177 describes some tests in mammography equipment, not defined in other publications. We conclude that there is no standardization in the nomenclature or in the performance and frequency of the tests, seeking greater scope and updating. (author)

  11. Ergonomic analyse of operation work in electric energy transmission substation; Analise ergonomica do trabalho de operacao de subestacoes de transmissao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Menegon, Nilton Luiz

    1993-04-01

    The activity by the workers in sub-stations which transmits and distributes electric energy is studied within the context of ergonomic, i.e., of its adequateness to the human being characteristics. In the introduction of this book the ideas of ergonomic related to the behaviour of the workers who works which continuous processes in control room are reviewed. The development of the ideas in this field as well as the methodology to be followed in this work are discussed. The technical system involving the activities of the workers in sub-station is presented. These activities are inserted within a broad context of the electric energy sector. An analysis concerning the problems in the ergonomic field which justifies the ergonomic intervention follows the previous study. The work situation is characterized. The formal organization of the work and its physical and cognitive demands are examined. The task is explained in detail. With the analysis of the activities based on the systematic observation of the work performed by the workers, we finish this study. Finely, a diagnosis of the work situation and the recommendations compromised whit the workers health and improvement of the performance is settled. (author) 27 refs., 26 figs.

  12. Analysis of electric power cogeneration using sugar cane bagasse; Uma analise da cogeracao de energia eletrica usando bagaco de cana-de-acucar

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Anna Cristina Barbosa Dias de

    1997-07-01

    Brazil impels its economy again. A development expected in 80 and 90 years it is real. This growth demands new technologies, new researches and bases that bear that growth. Electric power is in these bases, but Brazil is not ready for that. Electric power cogeneration possibility appears, using sugar cane bagasse. Alcohol and sugar plants have already that practice working with a low generation volume. With some investment this volume can be increased, adding about 10% to national energetic matrix. The aim of this work is to present a short time alternative for national electric matrix. It shows the energetic situation of the country, some experiences already implanted in some countries around the world and some options for equipment improvement used in alcohol and sugar plants. It is shown alternatives sources of electric power generation studied on Brazil, as well as the planning of National Energetic Program of ELETROBRAS. It analyses, in details, sugar cane bagasse use, which is used in Sao Paulo plants to generate electric power. Possible systems and troubles for its implantation in sugar and alcohol plants are discussed. (author)

  13. Geostatistical and stratigraphic analysis of deltaic reservoirs from the Reconcavo Basin, Brazil; Analise estratigrafica e geoestatistica de reservatorios deltaicos da Bacia do Reconcavo (BA)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Carlos Moreira

    1997-07-01

    This study presents the characterization of the external geometry of deltaic oil reservoirs, including the description of their areal distribution using geo statistic tools, such as variography and kriging. A high-resolution stratigraphic study was developed over a 25 km{sup 2} area, by using data from 276 closely-spaced wells of an oil-producer field from the Reconcavo Basin, northeastern Brazil. The studied succession records the progressive lacustrine transgression of a deltaic environment. Core data and stratigraphic cross sections suggest that the oil reservoirs are mostly amalgamated, delta-front lobes, and subordinately, crevasse deposits. Some important geometrical elements were recognized by the detailed variographic analysis developed for each stratigraphic unit (zone). The average width for the groups of deltaic lobes of one zone was measured from the variographic feature informally named as hole effect. This procedure was not possible for the other zones due to the intense lateral amalgamation of sandstones, indicated by many variographic nested structures. Net sand krigged maps for the main zones suggest a NNW-SSE orientation for the deltaic lobes, as also their common amalgamation and compensation arrangements. High-resolution stratigraphic analyses should include a more regional characterization of the depositional system that comprises the studied succession. On the other hand, geostatistical studies should be developed only after the recognition of the depositional processes acting in the study area and the geological meaning of the variable to be treated, including its spatial variability scales as a function of sand body thickness, orientation and amalgamation. (author)

  14. Statistical analysis of the potassium concentration obtained through; Analise estatistica da concentracao de potassio obtida por aerolevantamentos geofisicos em diferentes formacoes geologicas na regiao de Santa Maria, RS

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Joao Eduardo da Silva [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Estatistica]. E-mail: jesp61@gmail.com; Silva, Jose Luiz Silverio da; Pires, Carlos Alberto da Fonseca [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Lab. de Hidrogeologia; Strieder, Adelir Jose [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Lab. de Modelagem Geologica e Ambiental

    2007-07-01

    The present work was developed in outcrops of Santa Maria region, southern Brazil, Rio Grande do Sul State. Statistic evaluations were applied in different rock types. The possibility to distinguish different geologic units, sedimentary and volcanic (acid and basic types) by means of the statistic analyses from the use of airborne gamma-ray spectrometry integrating potash radiation emissions data with geological and geochemistry data is discussed. This Project was carried out at 1973 by Geological Survey of Brazil/Companhia de Pesquisas de Recursos Minerais. The Camaqua Project evaluated the behavior of potash concentrations generating XYZ Geosof 1997 format, one grid, thematic map and digital thematic map files from this total area. Using these data base, the integration of statistics analyses in sedimentary formations which belong to the Depressao Central do Rio Grande do Sul and/or to volcanic rocks from Planalto da Serra Geral at the border of Parana Basin was tested. Univariate statistics model was used: the media, the standard media error, and the trust limits were estimated. The Tukey's Test was used in order to compare mean values. The results allowed to create criteria to distinguish geological formations based on their potash content. The back-calibration technique was employed to transform K radiation to percentage. Inside this context it was possible to define characteristic values from radioactive potash emissions and their trust ranges in relation to geologic formations. The potash variable when evaluated in relation to geographic Universal Transverse Mercator coordinates system showed a spatial relation following one polynomial model of second order, with one determination coefficient. The statistica 7.1 software Generalist Linear Models produced by Statistics Department of Federal University of Santa Maria/Brazil was used. (author)

  15. The result analysis by A-Frame technique in coating failure detection; Analise dos resultados do uso da tecnica A-Frame na localizacao de falhas no revestimento

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fabio Amarante; Leite, Daniele C.F. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Oliver, Joao Hipolito L. [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil)

    2005-07-01

    This paper presents the method used to helps the on land pipeline integrity management, focusing on external corrosion control. The method is achieved by gathering together the data from an Over The Line Survey (OLS) and an In Line Inspection (ILI). As the corrosion occurs at a coating fault in a non-effective cathodic protection (cp) area, both coating and metal loss inspection data were employed in this method. The OLS is applied to pinpoint and graduate the coating faults in underground pipeline by using the Coating Attenuation / A-Frame (ACVG - Alternate Current Voltage Gradient) technic. The ILI is applied to measure the external metal loss (corrosion) by running a smart PIG tool. In some pipelines a huge number of coating fault can be found, but it doesn't mean that all of them must be repaired, so it is a need to identify the critical coating fault, so that the number of digging for coating repair can be drastically reduced. In the other way, as the smart PIG can provide data of corrosion in the pipe, the coating fault on a corroded area can be considered as a critical one. Together, those data may point the spot where the cathodic protection was not effective and the coating failure resulted in corrosion on the pipe. This method has been a helpful criterion to identify critical coating faults and reduce the overall repair cost, it can be also used to indirect evaluate the performance of cp system, since no corrosion indication on a coating fault area can be assumed that the CP is effective. (author)

  16. Characteristic parameters analysis on diagnostic X-ray beams for dosemeter calibration; Analise de parametros caracteristicos de feixes de raios-X diagnostico para calibracao de dosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paulo Marcio Campos de

    2008-07-01

    Ionizing radiation metrology is the base to achieve reliable dose measurements in ali areas; it is also part of the framework that is established to assure radiation protection procedures in order to avoid or minimize the harmful biological effect that may be caused by ionizing radiation. A well done metrology means the use of reliable instruments that comply with standard performance requirements worldwide accepted. Those instruments are expected to be calibrated by Metrology Laboratories under well defined conditions. The International Electrotechnical Commission (IEC) in Standard 61267 established the reference radiations for medical diagnostic x-ray equipment that are recommended to be used for calibrating dosimetric systems for diagnostic dosimetry. In this work, X-ray beam qualities were established in a Calibration Laboratory and their characteristics were analyzed through the measurement of beam parameters like inherent tube filtration, beam uniformity and field size, energy spectra and peak voltage for additional filtration with 94.425 por cent and 99.999 por cent purity filters. Also, the first half-value layer and the homogeneity coefficient were measured for the three RQR 2, RQR 6 and RQR 10 IEC beam qualities and they were analyzed according to the IEC standard. Air-kerma measurements were carried out with an ionization chamber that had its reliability confirmed through repetition and reproducibility reading tests. In 50 sets of measurements the maximum standard deviation found of 10 successive readings was 0.19 %; the maximum shift of the reading mean value at a fixed geometry condition was 0.80 % with an overall standard deviation of 0.23 %. Results showed that the use of different purity filters did not cause a relevant influence on the beam energy spectra. An ionization chamber was also calibrated against a standard dosimeter in ali implemented reference radiations and the relevant sources of uncertainties were estimated. Calibration could be done

  17. Analysis of natural radionuclides and lead in foods and diets; Analise de radionuclideos naturais e chumbo em produtos alimenticios e dietas

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Luciana

    1999-07-01

    The main purpose of the present study was to determine the lead-210, polonium-210 and lead concentrations in foods and diets. Consumption of food is generally the main route by which radionuclides can enter the human organism. Precision and accuracy of the methods developed were verifies by the analysis of reference materials from the International Atomic Energy Agency (IAEA). The method for polonium-210 analysis consisted of sample dissolution by using a microwave digester (open system) employing concentrated nitric acid and hydrogen peroxide, evaporation almost dryness, addition of hydrochloric acid, polonium deposition onto silver disc for six hours and counting by alpha spectrometry. Lead was analysed by atomic absorption technique. After sample dissolution in a microwave digester (using concentrated nitric acid and hydrogen peroxide) and dilution to 50 ml, 20{mu}l of the sample was injected in a pyrolytic graphite furnace - atomic absorption spectrophotometer equipped with Zeeman background correction. The assessment of the contaminants in foods and diets allowed to estimate the intake of these elements and for the radionuclides were also evaluated the radiation doses that the individuals selected were exposed by the food consumption. The effective dose for lead-210 by diets intake ranged from 1.3 to 4.3 {mu}Sv/year, corresponding to 25% of the resulting from polonium-210 intake. The dose due to the both natural radionuclides varied from 6.8 to 23.0 {mu}Sv/year. These values are in good agreement with the literature data. The value estimated by the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR, 1993) that is 60 {mu}Sv and lower than the dose of 0.02 Sv, limit established by ICRP, 1980. The lead levels found in the majority of the Brazilian foods are in good agreement with the values published by CONAT and FAO/WHO. However, some foods such as bean, potato, papaya, apple and rice present levels above of the recommended values by the

  18. Phase change heat transfer device for process heat applications

    International Nuclear Information System (INIS)

    Sabharwall, Piyush; Patterson, Mike; Utgikar, Vivek; Gunnerson, Fred

    2010-01-01

    The next generation nuclear plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperature system of heat exchangers, pumps and/or compressors. The heat transfer system is particularly challenging not only due to the elevated temperatures (up to ∼1300 K) and industrial scale power transport (≥50 MW), but also due to a potentially large separation distance between the nuclear and industrial plants (100+ m) dictated by safety and licensing mandates. The work reported here is the preliminary analysis of two-phase thermosyphon heat transfer performance with alkali metals. A thermosyphon is a thermal device for transporting heat from one point to another with quite extraordinary properties. In contrast to single-phased forced convective heat transfer via 'pumping a fluid', a thermosyphon (also called a wickless heat pipe) transfers heat through the vaporization/condensing process. The condensate is further returned to the hot source by gravity, i.e., without any requirement of pumps or compressors. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. Two-phase heat transfer by a thermosyphon has the advantage of high enthalpy transport that includes the sensible heat of the liquid, the latent heat of vaporization, and vapor superheat. In contrast, single-phase forced convection transports only the sensible heat of the fluid. Additionally, vapor-phase velocities within a thermosyphon are much greater than single-phase liquid velocities within a forced convective loop. Thermosyphon performance can be limited by the sonic limit (choking) of vapor flow and/or by condensate entrainment. Proper thermosyphon requires analysis of both.

  19. Optimization of a condensed-neon cooling system for a HTS synchronous motor with Gd-bulk HTS field-pole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Felder, B; Miki, M; Tsuzuki, K; Izumi, M [Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, 2-1-6, Etchujima, Koto-ku, Tokyo 135-8533 (Japan); Hayakawa, H, E-mail: d082028@kaiyodai.ac.j [Kitano Seiki Co. Ltd., 7-17-3, Chuo, Ota-ku, Tokyo 143-0024 (Japan)

    2010-06-01

    The axial-gap synchronous machine developed in our laboratory is based on Gd-bulk HTS field-pole magnets, able to trap a part of the magnetic flux they are submitted to when cooled down below T{sub c}. At the liquid nitrogen temperature, by the Pulsed-Field Magnetization (PFM), 1.04 T was trapped in 60 mm-diameter and 20 mm-thickness magnets, leading to an output power of the motor of 10 kW at 720 rpm. To enhance this performance, we have to increase the total amount of trapped flux in the bulk, the shortest way being to decrease the temperature of the bulk HTS. Thus, we focused on the improvement of the condensed-neon cooling system, a closed-cycle thermosyphon, so that it provided enough cooling power to lead the rotor plate enclosing the magnets to a low temperature. The present study implied coming out with a new fin-oriented design of the condensation chamber; hence, the numeric calculations and FEM software (ANSYS) heat transfer simulations were conducted for various shapes and positions of the fins. The trapezoidal design offering the best efficiency was then manufactured for testing in a heat-load test configuration, leading to cooling times divided by three and a maximum heat load endured of 55 W.

  20. Optimization of a condensed-neon cooling system for a HTS synchronous motor with Gd-bulk HTS field-pole magnets

    Science.gov (United States)

    Felder, B.; Miki, M.; Tsuzuki, K.; Izumi, M.; Hayakawa, H.

    2010-06-01

    The axial-gap synchronous machine developed in our laboratory is based on Gd-bulk HTS field-pole magnets, able to trap a part of the magnetic flux they are submitted to when cooled down below Tc. At the liquid nitrogen temperature, by the Pulsed-Field Magnetization (PFM), 1.04 T was trapped in 60 mm-diameter and 20 mm-thickness magnets, leading to an output power of the motor of 10 kW at 720 rpm. To enhance this performance, we have to increase the total amount of trapped flux in the bulk, the shortest way being to decrease the temperature of the bulk HTS. Thus, we focused on the improvement of the condensed-neon cooling system, a closed-cycle thermosyphon, so that it provided enough cooling power to lead the rotor plate enclosing the magnets to a low temperature. The present study implied coming out with a new fin-oriented design of the condensation chamber; hence, the numeric calculations and FEM software (ANSYS) heat transfer simulations were conducted for various shapes and positions of the fins. The trapezoidal design offering the best efficiency was then manufactured for testing in a heat-load test configuration, leading to cooling times divided by three and a maximum heat load endured of 55 W.

  1. National safeguard systems - Inspector formation

    International Nuclear Information System (INIS)

    Pontes, B.C.

    1986-01-01

    The safeguards' inspector profile, in consequence of the tasks to be performed is described. An activities'hierarchy which will lead, to the structure and content of an introductory course's curriculum is established. The auditing activity as well as the material verification are described in details. Complementary resources for the upgrading the inspector's knowledge and skills are analised and the paper concludes presenting the training period, its dinamics as well as the recrutment criterium for the candidates. (Author) [pt

  2. Analysis, modeling and optimum design of solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qin

    1998-12-31

    The object of this study was dynamic modeling, simulation and optimum design of solar DHW (domestic hot water) systems, with respect to different whether conditions, and accurate dynamic behaviour of the heat load. Special attention was paid to systems with thermosyphon and drain-back design. The solar radiation in Beijing (China) and in Denmark are analyzed both by theoretical calculations and the analysis of long-term measurements. Based on the weather data from the Beijing Meteorological Station during the period of 1981-1993, a Beijing Test Reference Year has been formulated by means of statistical analysis. A brief introduction about the Danish Test Reference Year and the Design Reference Year is also presented. In order to investigate the heat loss as a part of the total heat load, dynamic models for distribution networks have been developed, and simulations have been carried out for typically designed distribution networks of the circulation type. The influence of operation parameters such as the tank outlet temperature, the hot-water load and the load pattern, on the heat loss from the distribution networks in presented. It was found that the tank outlet temperature has a significant influence on the heat loss from a circulation type of distribution network, while the hot-water load and the load pattern have no obvious effect. Dynamic models of drain-back tanks, both as a separated tank and combined with a mantle tank, have been developed and presented. Models of the other basic components commonly used in solar DHW systems, such as flat-plate collectors, connection pipes, storage tanks with a heat exchanger spiral, and controllers, are also described. (LN) 66 refs.

  3. Use of radiological evaluation system from the Instituto de Radioprotecao e Dosimetria in the analysis of recent radiation accidents; Utilizacao do sistema de avaliacao radiologica do Instituto de Radioprotecao e Dosimetria na analise de acidentes radiologicos recentes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodolfo Julio da

    2013-07-01

    The response to an emergency situation involving ionizing radiation requires the joint participation of professionals from various kind of knowledge, belonging to public and private organizations (in the local, state and federal levels). The theme radiation tends to be an additional challenging factor - considering that it's, usually, remembered for its macabre and ominous aspect, in spite of the benefits provided by it - which makes the implementation of actions to protect the public, emergency professionals, the environment and property, very difficult. To this, we can add the complicating factor that, in most cases, the technician (holder of basic or advanced on the subject) is far !Tom the place where this action unfolds. The accident/incident takes the form of a radioactive source (sometimes orphaned, one that gone astray or even stolen) that is found by a person unaware of the risks to which they are being exposed or, let not forget about it, the non-observance of safety standards in industries and workplaces, by their own operators. Thus, before integrating emergency response plans with conventional plans specific to the prompt response to radiological emergencies, it is necessary that some measures had been anticipated and that some actions had, already, been planned - with the intention of mitigate health, psychological and economical damage, in ali of kind. To do this, since in the course of the second decade of the second millennium, and since you own a portable personal computer (Note or Netbook), or even with a mobile device (cellular) with a bit more resources, both of them previously updated, a responder (or even a qualified technician that is next to that fact) may already guide, at least, about a safety distances !Tom the source. Since he had knowledge about some characteristics of the source (its individual data), he can plan ahead about the possible serious situation that unfolds itself and emergency responders will find, when it get to the site. With the situation assessments done, the formal emergency team triggered will can prepare itself (with personnel and technical-materials facilities) to resolve the incident in the shortest time and with the least possible risks. (author)

  4. Selected Issues on CO2 in Compression Systems

    Energy Technology Data Exchange (ETDEWEB)

    Aarlien, R.

    2004-05-15

    Carbon Dioxide (CO2) has shown promising results as an alternative working fluid compared to the CFCs, HFCs and HCFCs. CO2 provides an environmental friendly alternative in a number of heat pump applications, in automobile air conditioning, and as a secondary fluid in refrigeration systems. The physical and the thermodynamic properties of CO2 differ considerably from the more conventional working fluids and offer new possibilities as well as design challenges for systems and components. On this background IEA Heat Pump Programme's Annex 27 was established. The main objective of the Annex has been to bring the CO2 heat pump technology closer to commercialization, by addressing critical issues of both basic and applied character. The scope of the work under this Annex includes compression heat pump, refrigeration and air-conditioning systems and components, with the main emphasis on heat pumps, using CO2 as working fluid. The term 'compression heat pump' covers vapor compression circuits with phase change. The term 'system' includes all the components used in a heating/cooling system from the heat pump to the inside unit, controls included. Results from 12 different research projects together with an extensive literature survey are presented. The projects are carried out as independent research projects, and the findings and the results are the sole responsibility of the authors. The following projects are presented: 1) Feasibility of transcritical CO2 systems for mobile space conditioning applications. 2) Use of CO2- and propane thermosyphons in combination with compact cooler in domestic freeze. 3) Heat transfer of carbon dioxide in an evaporator. 4) Correlating the heat transfer coefficient during in-tube cooling of turbulent supercritical CO2. 5) Heat transfer and pressure drop characteristics of super-critical CO2 in microchannel tubes under cooling. 6) Flow vaporization of CO2 in microchannel tubes. 7) Two-phase flow patterns during

  5. Systems

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Papers in this session describe the concept of mined geologic disposal system and methods for ensuring that the system, when developed, will meet all technical requirements. Also presented in the session are analyses of system parameters, such as cost and nuclear criticality potential, as well as a technical analysis of a requirement that the system permit retrieval of the waste for some period of time. The final paper discusses studies under way to investigate technical alternatives or complements to the mined geologic disposal system. Titles of the presented papers are: (1) Waste Isolation System; (2) Waste Isolation Economics; (3) BWIP Technical Baseline; (4) Criticality Considerations in Geologic Disposal of High-Level Waste; (5) Retrieving Nuclear Wastes from Repository; (6) NWTS Programs for the Evaluation of Technical Alternatives or Complements to Mined Geologic Repositories - Purpose and Objectives

  6. systems

    Directory of Open Access Journals (Sweden)

    Alexander Leonessa

    2000-01-01

    Full Text Available A nonlinear robust control-system design framework predicated on a hierarchical switching controller architecture parameterized over a set of moving nominal system equilibria is developed. Specifically, using equilibria-dependent Lyapunov functions, a hierarchical nonlinear robust control strategy is developed that robustly stabilizes a given nonlinear system over a prescribed range of system uncertainty by robustly stabilizing a collection of nonlinear controlled uncertain subsystems. The robust switching nonlinear controller architecture is designed based on a generalized (lower semicontinuous Lyapunov function obtained by minimizing a potential function over a given switching set induced by the parameterized nominal system equilibria. The proposed framework robustly stabilizes a compact positively invariant set of a given nonlinear uncertain dynamical system with structured parametric uncertainty. Finally, the efficacy of the proposed approach is demonstrated on a jet engine propulsion control problem with uncertain pressure-flow map data.

  7. A cooling concept of spent fuels in lag storage system

    International Nuclear Information System (INIS)

    Park, Jeong-Hwa; Yoo, Jae-Hyung; Park, Hyun-Soo

    1991-01-01

    A cooling concept of spent fuels by natural convection of hot cell air in storage pits was developed. Each storage pit was considered to be located below the hot cell floor and to accommodate only one spent fuel assembly. The aim of this study is to apply an appropriate cooling system to the design of a hot cell where considerable heat-generating fuels are handled. In such operations as disassembling, rod consolidation and packaging of spent fuels, a number of assemblies are on stand-by in the cell before and/or after the operations. A lag storage system can be used for temporary storage of spent fuels in nuclear facilities. Since the air in contact with bare fuel assemblies is potentially contaminated, it must be exhausted through high-efficiency particulate air (HEPA) filters. If the storage pit is completely isolated from the hot cell space, then it will require another separate ventilation system by forced convection of air, which will result in additional cost for the construction. In this work, however, a cooling system was proposed where natural convection of hot cell air itself is achieved by thermo-syphon. The cold air from the hot cell is supplied to the inlet provided at the bottom of each pit through the gap between the concrete pit wall and the interior thermal shield. This thermal shield is needed to form flow channels for cold and heated air, and to prevent the concrete from over-heating. The heated air exhausts from the outlet located at the top of cell wall. No additional HEPA filters are needed in this system because the heated air is routed back to the hot cell due to buoyancy-induced flow. The technical feasibility of this concept was validated by thermal analyses. As the key design constraints are the surface temperature of fuel cladding and the concrete temperature of the storage pit, the thermal analyses were focused on these parameters whether they follow within allowable limits or not. (author)

  8. Descriptive macroscopic anatomy of the central nervous system six-banded armadillo (Euphractus sexcintus, Linnaeus, 1758 and nine-banded armadillo (Dasypus novemcinctus, Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    João Victor Silva Araújo

    2016-02-01

    Full Text Available Armadillos of the species Dasypus novemcinctus and Euphractus sexcintus are xenarthrico is a mammal that inhabits fields and has several eating habits. This study proposes to analise the macroscopic anatomy of the nervous system of the armadillo peba, enabling comparisons with other mammals. Three animals of each species were to donated ICMBio - Chico Mendes Institute for Biodiversity, the Serra da Capivara National Park, authorized by SISBIO 22826-01, victims of poaching and they had died. The animals were stored in Histology and Embryology Laboratory of the Morphology Department of Health Sciences Center of the Federal University of Piauí. Initially, they were fixed with 10% buffered formalin for 24 hours and then dissected for observation of the organs forming the central nervous system. The central nervous system Armadillo consists of the brain and spinal cord. The macroscopic morphology, the central nervous system Armadillo resembles those of other mammals, however, anatomical features found in the brain and spinal cord suggest a higher olfactory expression and motor skills.

  9. SYSTEM

    Directory of Open Access Journals (Sweden)

    K. Swarnalatha

    2013-01-01

    Full Text Available Risk analysis of urban aquatic systems due to heavy metals turns significant due to their peculiar properties viz. persis tence, non-degradab ility, toxicity, and accumulation. Akkulam Veli (AV, an urba n tropical lake in south India is subjected to various environmental stresses due to multiple waste discharge, sand mining, developmental activities, tour ism related activitie s etc. Hence, a comprehensive approach is adopted for risk assessment using modified degree of contamination factor, toxicity units based on numerical sediment quality guidelines (SQGs, and potentialecological risk indices. The study revealed the presence of toxic metals such as Cr, C d, Pb and As and the lake is rated under ‘low ecological risk’ category.

  10. Experimental energetic analysis of gas natural-powered fuel cell cogeneration plant; Analise energetica experimental de uma planta de co-geracao com celulas a combustivel e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose G.M.; Lopes, Francisco C.; Silva Junior, Fernando R.; Soares, Guilherme F.W.; Serra, Eduardo T. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economy of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  11. Energetic-economical analysis of a stationary for energy generation with fuel cells and natural gas reforming; Analise energetico-economica de um sistema estacionario de geracao de energia com celulas a combustivel e reforma de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose Geraldo de Melo; Silva Junior, Fernando Rodrigues; Silva, Cristiane Abrantes da; Soares, Guilherme Fleury Wanderley; Lopes, Francisco da Costa; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: furtado@cepel.br; Codeceira Neto, Alcides [Companhia HidroEletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economicity of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  12. Impact of inclusion of synchrophasor measuring in estimation of states and generalized observability analysis; Impacto da inclusao de medicao sincrofasorial na estimacao de estados e na analise de observabilidade generalizadas

    Energy Technology Data Exchange (ETDEWEB)

    Krefta, Gilmar Francisco [Compania Paranaense de Energia (COPEL), Curitiba, PR (Brazil). Dept. de Protecao de Sistemas Eletricos], E-mail: gilmar.krefta@copel.com; Lourenco, Elizete Maria [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Eletrica], E-mail: elizete@eletrica.ufpr.br

    2009-07-01

    This study aims to establish elements, data and criteria for defining a grid for assessing the inclusion of the measurement synchrophasor in state estimation of electric power systems and the analysis of topological observability.

  13. Volume totalizers analysis of pipelines operated by TRANSPETRO National Operational Control Center; Analise de totalizadores de volume em oleodutos operados pelo Centro Nacional de Controle e Operacao da TRANSPETRO

    Energy Technology Data Exchange (ETDEWEB)

    Aramaki, Thiago Lessa; Montalvao, Antonio Filipe Falcao [Petrobras Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Marques, Thais Carrijo [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

    2012-07-01

    This paper aims to present the results and methodology in the analysis of differences in volume totals used in systems such as batch tracking and leak detection of pipelines operated by the National Center for Operational Control (CNCO) at TRANSPETRO. In order to optimize this type of analysis, software was developed to acquisition and processing of historical data using the methodology developed. The methodology developed takes into account the particularities encountered in systems operated by TRANSPETRO, more specifically, by CNCO. (author)

  14. The quality of information in electronic scientific publications on the Internet: challenges and proposals

    Directory of Open Access Journals (Sweden)

    Marcelo SABBATINI

    2016-03-01

    Full Text Available The present work analises the main questions and hurdles involved in the adoption of a electronic scientific publication system, those related to the scientific community practices and rules of conduct. We emphasize the quality certification through peer review, interity and legitimiy maintenance and privacity preservation in the digital environment. Furthermore, we analise the academic community own perception of electronic journals available in Internet and its impacts in tenure and prommotion processes.

  15. Pressurized Hybrid Heat Pipe for Passive IN-Core Cooling System (PINCs) in Advanced Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Mo; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2016-05-15

    The representative operating limit of the thermosyphon heat pipe is flooding limit that arises from the countercurrent flow of vapor and liquid. The effect of difference between wetted perimeter and heated perimeter on the flooding limit of the thermosyphons has not been studied; despite the effect of cross-sectional area of the vapor path on the heat transfer characteristics of thermosyphons have been studied. Additionally, the hybrid heat pipe must operate at the high temperature and high pressure environment because it will be inserted to the active core to remove the decay heat. However, the previously studied heat pipes operated below the atmospheric pressure. Therefore, the effect of the unique geometry for hybrid heat pipe and operating pressure on the heat transfer characteristics including the flooding limit of hybrid heat pipe was experimentally measured. Hybrid heat pipe as a new conceptual decay heat removal device was proposed. For the development of hybrid heat pipe operating at high temperature and high pressure conditions, the pressurized hybrid heat pipe was prepared and the thermal performances including operation limits of hybrid heat pipe were experimentally measured. Followings were obtained: (1) As operating pressure of the heat pipe increases, the evaporation heat transfer coefficient increases due to heat transfer with convective pool boiling mode. (2) Non-condensable gas charged in the test section for the pressurization lowered the condensation heat transfer by impeding the vapor flow to the condenser. (3) The deviations between experimentally measured flooding limits for hybrid heat pipes and the values from correlation for annular thermosyphon were observed.

  16. Comparative analysis between P1 and B1 equations for neutron moderation; Analise comparativa entre os metodos de obtencao e das solucoes das equacoes P1 e B1 para moderacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    In order to calculate the neutron flux in nuclear reactors, B1 or P1 equations are solved by numerical methods for several groups of energy. The neutron fluxes obtained from the solutions of the B1 and P1 equations are similar when they are applied to large nuclear power reactors. However, an important difference between the two fluxes is that the system of P1 equations uses one more approximation than the B1 system and then, its flux is less precise. The present work shows the relations between both equations and analyzes for what conditions the two equations systems are equivalent. Furthermore, this equations are numerically solved in 54 groups of energy for a quadrangular arrange. (author)

  17. Prediction of petrophysical properties by 3D reconstruction of porous media from image analysis; Estimativa de propriedades petrofisicas atraves da reconstrucao 3D do meio poroso a partir da analise de imagens

    Energy Technology Data Exchange (ETDEWEB)

    Gasperi, Patricia Martins Silva de

    1999-07-01

    The aim of this work is to investigate and apply a method for predicting petrophysical properties from bidimensional petrographic image data. Based on the assumption of statistical homogeneity, the method uses stochastic simulation to reconstruct the porous media tridimensional structure. The geometrical characterization of the simulated media allows the construction of a network model to simulate fluid flow and estimate permeability, formation factor, mercury capillary pressure curves and resistivity index as function of water saturation. This method is applied to four porous systems with different heterogeneity levels. The results demonstrate that good predictions depend on the appropriate image acquisition resolution, which identifies pores and throats that effectively control the flow properties of the system. The capillary pressure curves suggest the necessity of scale composition. The electrical properties are affected by samples porosity, with reliable estimates being restricted to water-wet systems. (author)

  18. Thermodynamics analysis of an autonomous distillery operating with high steam parameters and two different distillation technologies; Analise termodinamica de uma destilaria autonoma operando com altos parametros de vapor e duas tecnologias diferentes de destilacao

    Energy Technology Data Exchange (ETDEWEB)

    Palacio, Jose Carlos Escobar; Lora, Electo Eduardo Silva; Venturini, Osvaldo Jose; Santos, Jose Joaquim [Universidade Federal de Itajuba (NEST/UNIFEI), MG (Brazil). Nucleo de Excelencia em Geracao Termeletrica e Distribuida; Moura, Adler [DEDINI Industrias de Base S.A., Piracicaba, SP (Brazil)

    2008-07-01

    The objective of this paper is to carry-out an integrated thermodynamic analysis for an ethanol distillery and the mill cogeneration plant. In previous works the cogeneration system has been analyzed separately using thermoeconomic tools to calculate the products cost and to define the best scheme and parametric alternative. Similar researches were carried-out aiming to reduce the energy consumption in the distillation process. This paper proposes a simultaneous evaluation of both systems using an exergoeconomic tools to improve the energy integration of process. (author)

  19. Métodos de analise dos danos da lagarta da espiga¹, em médias de gerações envolvendo IAC Maya e Zapalote Chico Method for analysis of damage of the corn earworm heliothis zea in generation means from IAC Maya and Zapalote Chico

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Marques Rezende

    1982-01-01

    utilizing the revised scale described by WIDSTROM (27. The data obtained was analised by two different ways. The grades were distributed at first in two different classes: grades 0 and 1 and grades > 2. The grades were afterwards distributed in the following two classes: grades 0 and grades > 1. The chi-square test was applied to verify which of the two types of classes adjusts better with their respective expected ratios. The results showed that when the grades were divided in the classes 0+1 and > 2 the data were more uniform within each treatment. The analysis of variance for each damage class separately, presented F values highly significant for the classes zero and zero plus one, whereas for the classes > 1 and > 2 the damage averages were very similar and the F values were not significant. The class zero plus one had F value higher and the coefficient of variation smaller than the class zero. The ZC 2451 corn compared to the variety IAC Maya XII, exibited good resistance to the corn earworm, under the field conditions of Campinas, State of São Paulo, Brazil. This resistance is of the type non preference and or antibiosis, because there was a higher percentage of ears of ZC 2451 free of earworm damage.

  20. Modelling of the thermal behaviour of a two-phase closed thermosyphon

    OpenAIRE

    Fadhl, Bandar

    2016-01-01

    This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London Interest in the use of heat pipe technology for heat recovery and energy saving in a vast range of engineering applications has been on the rise in recent years. Heat pipes are playing a more important role in many industrial applications, especially in increasing energy savings in commercial applications and improving the thermal performance of heat exchangers. Computational techniq...

  1. Simulation of a gas thermal plant in the new environment of the Brazilian electricity sector: a risk versus return analysis; Simulacao de uma usina termica a gas no novo contexto do setor eletrico brasileiro: uma analise risco versus retorno

    Energy Technology Data Exchange (ETDEWEB)

    Pinhel, Antonio Carlos da Costa

    2000-12-15

    This work has as its main objective the evaluation of the financial impact in respect to the investment in a thermal gas plant, taking into consideration the complementary role of thermal electricity generation within the interconnected system. A risk x return analysis is performed, by means of computer simulations based on different assumptions, among which the following: costs involved; electric system expansion scenarios; flexible plant operation; long and short term contracting of generation capacity. The combination between flexibility in operation (the level of take/ship or pay in gas contracts) - which in favorable hydraulic periods allows for the use of water which would otherwise overflow through spillways or stored at low value - and a trading strategy - which reduces the risk exposure to electricity spot prices - makes it possible to have a significant increase in the cost effectiveness of the project. Among the main conclusions of the study, the following should be highlighted: the electricity price gap occurring between the prices practiced in present contracts between suppliers and distributors and those of the 'new energy', resulting from the system expansion; the relevance the flexibility in fuel purchase, in order to allow for the cost reduction of the energy generated, through the elimination of unnecessary gas consumption; the high risk associated to strategies in which investors come up with no signed long term power purchase agreements; and the risks for the system expansion, considering the consumer point of view. (author)

  2. Exergoeconomic and thermodynamics analysis of an autonomous distillery operating with different technologies of cogeneration and distillation; Analise termodinamica e exergoeconomica de uma destilaria autonoma operando com tecnologias diferentes de cogeracao e destilacao

    Energy Technology Data Exchange (ETDEWEB)

    Palacio, Jose Carlos Escobar; Lora, Electo Eduardo Silva; Venturini, Osvaldo Jose; Santos, Jose Joaquim; Reno, Maria Luiza Grillo [Universidade Federal de Itajuba (NEST/UNIFEI), MG (Brazil). Nucleo de Excelencia em Geracao Termeletrica e Distribuida; Moura, Adler [DEDINI Industrias de Base S.A., Piracicaba, SP (Brazil)

    2008-07-01

    The present work evaluates through thermodynamics and exergoeconomics the performance of an autonomous distillery. This is based in cogeneration systems which operate with different parameters and technologies. On the base of the carried out was possible to quantify the improvement obtained in the distillery performance indicators when it works with high steam parameters and technologies which increase the energy efficiency of distillation. (author)

  3. Simulation of a gas thermal plant in the new environment of the Brazilian electricity sector: a risk versus return analysis; Simulacao de uma usina termica a gas no novo contexto do setor eletrico brasileiro: uma analise risco versus retorno

    Energy Technology Data Exchange (ETDEWEB)

    Pinhel, Antonio Carlos da Costa

    2000-12-15

    This work has as its main objective the evaluation of the financial impact in respect to the investment in a thermal gas plant, taking into consideration the complementary role of thermal electricity generation within the interconnected system. A risk x return analysis is performed, by means of computer simulations based on different assumptions, among which the following: costs involved; electric system expansion scenarios; flexible plant operation; long and short term contracting of generation capacity. The combination between flexibility in operation (the level of take/ship or pay in gas contracts) - which in favorable hydraulic periods allows for the use of water which would otherwise overflow through spillways or stored at low value - and a trading strategy - which reduces the risk exposure to electricity spot prices - makes it possible to have a significant increase in the cost effectiveness of the project. Among the main conclusions of the study, the following should be highlighted: the electricity price gap occurring between the prices practiced in present contracts between suppliers and distributors and those of the 'new energy', resulting from the system expansion; the relevance the flexibility in fuel purchase, in order to allow for the cost reduction of the energy generated, through the elimination of unnecessary gas consumption; the high risk associated to strategies in which investors come up with no signed long term power purchase agreements; and the risks for the system expansion, considering the consumer point of view. (author)

  4. Real time stagger of electric network advanced analysis functions of a modern control center; Escalonamento em tempo real das funcoes avancadas de analise de rede eletrica de um moderno centro de controle

    Energy Technology Data Exchange (ETDEWEB)

    Zagari, Eduardo Nicola Ferraz

    1996-02-01

    This work presents two models for implementation of staggers for network analysis functions in real time for a control center. The methodology is described. Tests were performed in a electric power system of Campinas region, Sao Paulo sate - Southeast Brazil. Results are presented.

  5. Model of spatial analysis of electric power market using the Fuzzy C-Means technical classification; Modelo de analise espacial de mercado de energia eletrica utilizando a tecnica de classificacao Fuzzy C-Means

    Energy Technology Data Exchange (ETDEWEB)

    Neto, J.C. [Companhia Energetica de Goias (CELG-D), Goiania, GO (Brazil)], E-mail: joao.cn@celg.com.br; Lima, W.S. [Votorantim Siderurgia, Resende, Rio de Janeiro, RJ (Brazil). Gerencia Geral de Tecnologia], E-mail: wagner.lima@vmetais.com.br

    2009-07-01

    The power distribution companies live with an antagonistic reality: an increasing energy demand, due to steady economic and population growth, and a limitation on their financial resources to expand its network. Therefore, it is essential an improvement in activity of planning of the power distribution system trying to improve the application of available resources. In this context fits the application of Geographic Information System combined with clustering techniques and classification in order to enhance the planning process, giving the planner a more complete picture of the consumer market by the distributor. This paper presents a system that makes use of Geographic Information System combined with the technique of clustering and classification Fuzzy C-Means, with the aim of analyzing the distribution of network load and the performance of the technique. Each group performed leads to a spatial representation (scenario). This, together with an index measuring the performance of the group (intra-group and inter-group) implemented in this work, provides a favorable environment for spatial analysis of the electric power market.

  6. Analysis of dose in heterogeneity adjuvant radiotherapy after surgical treatment of cases of breast cancer; Analise da heterogeneidade de dose em radioterapia adjuvante apos tratamento cirurgico de casos de cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Grechi, Bruna E.; Schwarz, Ana Paula, E-mail: anapaulaschwarz@yahoo.com.br [Centro Universitario Franciscano (UNIFRA), Santa Maria, RS (Brazil); Teston, Adriano; Rodrigues, Joanilso S. [Clinica de Radioterapia Santa Maria, Santa Maria, RS (Brazil)

    2013-12-15

    Assuming the systems planning radiotherapy recognize all body structures of the same density (d=1 g/cm³), variations in electron density within the irradiated area, as is the case of patients who undergo reconstruction mammary processes and use tissue expanders, may influence the dose distribution in the treatment and may produce heterogeneities which are not measured by changing its actual distribution into healthy tissues or in the target volume to be irradiated. Through the calculation of the algorithms' dose distribution of the XiO® planning system (Fast Fourier Transform, Convolution, Superposition, Fast Superposition e Clarkson), when using correction of heterogeneity between tissues of different densities, there was obtained a percentage ratio of dose increase in the structures of interest, and of the amount of absorbed dose by healthy organs adjacent to the target volume. (author)

  7. Performance analysis of covered conductors and aerial bundled cables by the finite elements method; Analise de desempenho de cabos cobertos e pre-reunidos pelo metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joao Jose dos Santos

    1996-12-31

    The covered conductors and the aerial bundled cables (abc) for overhead distribution systems 15 kV systems, has been a good solution for the main brazilian electrical utilities when applied in areas with to limited space on poles and to satisfy the performance claimed in tree areas or narrow streets, focusing people safety and electrical service continuity. Otherwise, in this work it is presented that these cables show failures that can be related to the solid isolants used. It is showed the laboratory tests results to characterize its thermal and electric behaviour and an application of the Finite Element Method through the software Flux 2 d was done. The results obtained showed the requirements to be demanded through the specification and proposals elements to change the standard. (author) 57 refs., 20 figs., 73 tabs.

  8. Performance analysis of covered conductors and aerial bundled cables by the finite elements method; Analise de desempenho de cabos cobertos e pre-reunidos pelo metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joao Jose dos Santos

    1997-12-31

    The covered conductors and the aerial bundled cables (abc) for overhead distribution systems 15 kV systems, has been a good solution for the main brazilian electrical utilities when applied in areas with to limited space on poles and to satisfy the performance claimed in tree areas or narrow streets, focusing people safety and electrical service continuity. Otherwise, in this work it is presented that these cables show failures that can be related to the solid isolants used. It is showed the laboratory tests results to characterize its thermal and electric behaviour and an application of the Finite Element Method through the software Flux 2 d was done. The results obtained showed the requirements to be demanded through the specification and proposals elements to change the standard. (author) 57 refs., 20 figs., 73 tabs.

  9. Performance analysis of progressive cavity pumps in oil wells with high BSW (Basic Sediment Water); Analise do desempenho de elastometros do bombeio de cavidades progressivas em pocos de petroleo com elavado BSW (Basic Sediment Water)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Cindi Alves; Santos, Joao Paulo Lobo dos; Lobato, Ana Katerine de Carvalho Lima; Santos, Luiz Carlos Lobato dos [Universidade Federal da Bahia, BA (Brazil); Duarte, Lindemberg de Jesus Nogueira [Universidade Federal do Rio Grande do Norte, RN (Brazil)

    2012-07-01

    One of the most important equipment in the progressing cavity pump (PCP) is the subsurface pump, which comprises a rotor and a stator covered internally by an elastomer. This is responsible for sealing the pump and, consequently, for elevating the fluids. In fact, this polymer is used because of the ability to generate pressure in the pump by the seals formed between the cavities. In order to guarantee that the elastomer will have a good performance in the PCP system certain requirements need to be checked, such as: stress, elongation, hardness, resilience, permeability and adhesion. The fluids and solids handled by the PCP system, allied to high temperatures can cause premature wear in the elastomers. The most common reactions which are also observed in most of the wells are swelling, shrinkage, softening, hardening and explosive decompression. In this sense, the aim of this work is to study some elastomers which were chosen based on compatibility tests conducted by a major oil company. The problems that occurred in the wells will be analyzed in order to verify whether the choice of the elastomer had some influence on system failure. For this purpose, the intervention reports, efficiency tests and failure analysis reports will be used. At the end of this work, it was possible to diagnose the causes, consequences and solutions to inherent problems at various oil wells in a field that is in an advanced stage of recovery. Finally, it was concluded that simple changes in the process of compatibility analysis would help to increase the reliability level of the tests, especially the problems observed during the PCP operation in hostile environments. (author)

  10. Environmental analysis of the proton exchange membrane fuel cell on the subject of life cycle assessment; Analise ambiental da celula a combustivel de membrana trocadora de protons sob o enfoque da avaliacao do ciclo de vida

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, Sandra Harumi

    2006-07-01

    The energy is the fuel of growth and an essential requirement for the socioeconomic development. However, the current production model is based on fossil fuels, considered as threat to man and nature. As for, the relating to the human activities and their effects on the environment, they are handled by the implementation of a more rigid model of environmental control and the mobilization of the society in favor of technologies with less energy impact. In view of this scenario, the Proton Exchange Membrane Fuel Cell - PEMFC has been recognized as a key for the vital need of a clean and efficient energy. Considering the conventional power generation system, their advantages during usage configure its application as an ideal option for several utilities, especially in the mobile sector. Even though, the focus on several environmental evaluations in energy systems is referred back to the initial stage of it use, the employment relating to production of the system and to final destination should be considered, since these also present impacts. In the case of PEMFC, their previous and subsequent phases of use are issues related to the platinum catalysts, which indicates an environmental importance that cannot be overlooked. In this sense, the Life Cycle Assessment has been used to understand and to question the risks and opportunities that are associated to certain product, starting from a systemic concept of their relationships with the environment. It is precisely in this context that the present research intends to present its major contribution, starting from an exploratory study towards the its objectives to provide an environmental analysis of such technology linked to post stage of powder-use of the membrane electrode assembly - MEA, concerning the platinum catalysts, on the subject of Life Cycle Assessment - LCA. To attain such aim, the relationships between energy, environment and development are presented and discussed, as well as, the Fuel Cell technology and

  11. Analyses of the use of natural gas in solar power plants (CSP) hybridization in the Sao Francisco Basin (BA); Analise do uso de gas natural na hibridizacao de plantas termosolares (CSP) na Bacia do Sao Francisco (BA)

    Energy Technology Data Exchange (ETDEWEB)

    Malagueta, Diego Cunha; Penafiel, Rafael Andres Soria; Szklo, Alexandre Salem; Dutra, Ricardo M.; Schaeffer, Roberto [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil)

    2012-07-01

    This study assessed the feasibility of Concentrated Solar Power plants (CSP) in Northeast, Brazil. It focused on parabolic trough solar power plants, which is the most mature CSP technology; and evaluated plants rated at 100 MWe, dry cooling systems (due to the low water availability in Northeast), and with and without hybridization based on natural gas (degree of hybridization varying from 25 to 75%). Hence, the capacity factor of the simulated plants hovered between 23 and 98%, according to the degree of hybridization and the choice of the thermodynamic cycle of the natural gas fueled thermal system: Rankine or combined cycle. The CSP plants were simulated at Bom Jesus da Lapa, in the semi-arid region of Bahia. Given the prospects for natural gas resources in the Sao Francisco Basin, different scenarios for the gas prices were tested. Moreover, two scenarios were tested for the cost of the CSP plants, one based on the current financial environment and the other based on incentive policies, such as fiscal incentives and loans. Findings show that while simple plants levelized costs (LCOE) hovered around 520 R$/MWh, for hybrid plants LCOE may reach 140 to 190 R$/MWh. Therefore, this study proposed incentive policies to promote the increasing investment in hybrid CSP plants. (author)

  12. Historic case: analysis and mediation of mechanical stresses according to ASTM 837 in GASBOL pipelines in Curriola River; Caso historico: analise e medicao de tensao mecanica conforme ASTM 837 no gasoduto GASBOL no Rio Curriola

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Joao C. [Transportadora Brasileira Gasoduto Bolivia-Brasil, S.A., Rio de Janeiro, RJ (Brazil); Filippin, Carlo G.; Kapp, Walter A.; Horbatiuk, Borys D. [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)

    2005-07-01

    The Bolivia-Brazil Natural Gas Pipeline with 2,600 kilometers of extension from Rio Grande City in Bolivia down to Canoas City, in Brazil s south. The pipeline crosses quite a few types of geological fields and topography. The pipeline's south section is quite interesting due of its bumpy topography combined with a variety of geological materials, such as, colluviums deposits and landslide areas. Curriola River at kilometer 408 of the pipeline, east region of Parana's State, crosses inclination slopes as steeply as 40 degrees. A superficial drainage system was built in order to prevent soil's motions. Every year, during the rainy season, that system was incapable of a properly drainage, generating tension cracks mainly because the embankment is more than 6 meters high. This paper's goal is to present a historical case including some site characterization, with all the mechanical investigation made, including mechanical stresses status, residual stresses assessment and a total combined stress decompose attempt into its components and how they were used to support the studies for the slope stabilization and gas pipeline integrity. (author)

  13. Application of perturbation methods for sensitivity analysis for nuclear power plant steam generators; Aplicacao da teoria de perturbacao a analise de sensibilidade em geradores de vapor de usinas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Gurjao, Emir Candeia

    1996-02-01

    The differential and GPT (Generalized Perturbation Theory) formalisms of the Perturbation Theory were applied in this work to a simplified U-tubes steam generator model to perform sensitivity analysis. The adjoint and importance equations, with the corresponding expressions for the sensitivity coefficients, were derived for this steam generator model. The system was numerically was numerically solved in a Fortran program, called GEVADJ, in order to calculate the sensitivity coefficients. A transient loss of forced primary coolant in the nuclear power plant Angra-1 was used as example case. The average and final values of functionals: secondary pressure and enthalpy were studied in relation to changes in the secondary feedwater flow, enthalpy and total volume in secondary circuit. Absolute variations in the above functionals were calculated using the perturbative methods, considering the variations in the feedwater flow and total secondary volume. Comparison with the same variations obtained via direct model showed in general good agreement, demonstrating the potentiality of perturbative methods for sensitivity analysis of nuclear systems. (author) 22 refs., 7 figs., 8 tabs.

  14. Study on the relationship between water exergy and enthalpy applicable to the energetic analysis of steam thermodynamic cycles; Estudo da relacao entre exergia e entalpia da agua, aplicavel a analise energetica e exergetica de ciclos termodinamicos a vapor

    Energy Technology Data Exchange (ETDEWEB)

    Llagostera, Jorge [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: llagost@fem.unicamp.br

    1995-07-01

    This paper presents a thermodynamic relation, defined to improve methodologies in Second Law Analysis of thermal systems. This relation is defined dividing the specific thermomechanical exergy by the specific enthalpy of a substance, adopting as reference a selected thermodynamic state. This relation is determined and analyzed for liquid water and steam in a range of temperatures (30 deg C - 700 deg C) and pressures (0.101325 MPa - 18.1 Mpa). The behavior of the proposed relation is compared against the exergy behavior as function of temperature and pressure. The proposed relation can be used to compare and evaluate thermodynamic states that have similar exergy content. It makes possible to identify the states presenting higher exergetic level per enthalpy unit. This concept can be useful in thermodynamic analysis and optimization of steam cycles and thermal processes. (author)

  15. Preconcentration of metallic elements by complexation with ammonium pyrrolidine dithiocarbamate (APDC) for atomic absorption analysis; Pre concentracao de elementos metalicos por complexacao com ditiocarbamato de amonioe prirrolidina (APDC) para analise por absorcao atomica

    Energy Technology Data Exchange (ETDEWEB)

    Santos Coelho, Ricardo dos; Dantas, Elizabeth S.K. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-10-01

    Ammonium pyrrolidine dithiocarbamate (APDC) forms stable chelates with many metals being therefore, used in systems of preconcentration for determination of heavy metals in water. In this work, the metals were complexed with APDC and extracted with methyl isobutyl ketone (MIBK). The results showed that the studied metals (Co, Cu, Fe, Ni, Pb, Cr and Cd), in the range of 2 to 5 {mu}g, in 100 ml of sample, were quantitatively extracted in only one stage using 10 ml of MIBK and 5 ml of 4% APDC. The pH must be between 4 and 5. The complexes stability was also studied. The proposed method can be applied to pre concentrate heavy metals in natural waters. (author). 4 refs., 1 fig., 3 tabs.

  16. A pre-analysis for the optimal operational scheduling of a pipeline network; Uma pre-analise do problema de otimizacao da programacao das operacoes de uma malha dutoviaria

    Energy Technology Data Exchange (ETDEWEB)

    Czaikowski, Daniel I.; Brondani, William M.; Arantes, Lucas G.; Boschetto, Suelen N.; Lueders, Ricardo; Magatao, Leandro; Stebel, Sergio L. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Ribas, Paulo C. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    This work suggests a Pre-analysis in the input parameters of an optimization system (Bonacin et al., 2007; Boschetto et al., 2008). The proposed method is based on programming techniques that use lists of objects threaded, where objects are elements belonging to the same class, according to the concept of the object-oriented programming. The Preanalysis makes a previous evaluation of a batch sequencing, getting information to be entered into an optimization block. The continuous time Mixed Integer Linear Programming (MILP) model gets such information and determines the scheduling. The models are applied on a pipeline network that connects different areas including refineries, terminals, and final clients. Many oil derivatives (e.g. gasoline, liquefied petroleum gas, naphtha) can be sent or received in this network. The Pre-analysis objective is to reduce the computational time of an MILP model, and the proposed approach can aid the decision-making process to obtain a more detailed scheduling. (author)

  17. Thermodynamic analysis of mechanical behaviour in the elastic region of blends of recycled poly (ethylene terephthalate) and recycled polyolefins; Analise termodinamica do comportamento mecanico na regiao elastica de blendas de poli (tereftalato de etileno) reciclado e poliolefinas recicladas

    Energy Technology Data Exchange (ETDEWEB)

    Marconcini, Jose M. [Universidade Federal do Parana Univ. (UFPR), Curitiba, PR (Brazil). Inst. de Tecnologia para o Desenvolvimento; Ruvolo Filho, Adhemar [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Quimica]. E-mail: adhemar@power.ufscar.br

    2006-10-15

    This work describes the study using mechanical tests with the blend of recycled poly(ethylene terephthalate) (PET) and recycled polyolefin with and without the addition of polypropylene grafted with maleic anhydride and poly(ethylene-co-octene-1). A thermodynamic approach based on the Helmholtz work function was applied in the analysis of mechanical tests, correlating the effects of energy storage and from the compatibilizer on the elastic region of the materials. For the system studied, the polyolefin-rich region shows higher storage of elastic energy corroborating the morphology images obtained from SEM analysis. The thermodynamic analysis seems a useful tool to evaluate the compatibilizer effect in polymeric immiscible blends. In this work, more specifically, this method was used to analyze the mechanical behavior of different compositions of recycled polymeric commodity materials. (author)

  18. Efficiency analysis on the use of internal lining in the Bolivia-Brazil gas pipeline; Analise da eficiencia do uso de revestimento interno na tubulacao do gasoduto Bolivia-Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Frisoli, Caetano [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil); Silva, Marcos Jose Moraes da [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Bittencourt, Maria Angelica Santos; Coelho Junior, Robson Teixeira [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    The internal lining in gas pipelines aims the reduction of roughness and, consequently, the friction factor, therefore resulting in a reduction of pressure drop in natural gas flowing. During Bolivia-Brazil gas pipeline basic design, the cost benefit of internal coating was analyzed, in terms of friction factor reduction and distances between Compressor Stations. It was observed an increase of transport capacity and reduction of compressors' power, thus leading to its utilization. Since the pipeline is already in operation, using a SCADA system with Advanced Functions, a comparison between the current real friction factor in the pipeline with that theoretical values used during the design phase becomes possible. Through this comparison, it is possible to evaluate internal coating's efficiency, quantifying its real benefit for gas pipelines. (author)

  19. Thermoeconomic and thermodynamics analysis of a sugarcane plant that produces energy surplus for commercialization; Analise termodinamica e termoeconomica de uma usina sucroalcooleira que produz excedente de energia para comercializacao

    Energy Technology Data Exchange (ETDEWEB)

    Fiomari, Marcelo Caldato; Mashiba, Marcos Hideo da Silva; Lima, Rodrigo dos Santos; Maia, Cassio Roberto Macedo; Ramos, Ricardo Alan Verdu [Universidade Estadual Paulista (NUPLEN/UNESP), Ilha Solteira, SP (Brazil). Dept. de Engenharia Mecanica. Nucleo de Planejamento Energetico, Geracao e Cogeracao de Energia], e-mail: nuplen@dem.feis.unesp.br

    2006-07-01

    In this work, thermodynamic and thermo economic analyses of a plant resulted from an expansion of the Pioneiros Distillery's cogeneration system are carried out, which is constituted basically by a boiler that produces 140 ton/h of steam at high pressure and temperature (6,6 MPa and 530 deg C, respectively), by a condensation-extraction turbine that drives a electrical generator producing 32 MW, being the mechanical drivers realized by electrical engines. By means of thermodynamic analyses it's possible to define some plant's performance indexes as well as evaluate the global use of energy in each component. The thermo economic analysis allows evaluating the costs of capital and fuel reflexes in the composition of the products (steam and electricity) costs. (author)

  20. Analysis methodology of power generation/cogeneration designs in VNG (Vehicular Natural Gas) stations; Metodologia de analise de projetos de geracao/cogeracao em postos GNV (Gas Natural Veicular)

    Energy Technology Data Exchange (ETDEWEB)

    Romanos, Rafael Reami [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil)

    2008-07-01

    This work presents the methodology for analysis of generation/cogeneration projects in NGV filling stations, determining the influence of critical parameters in its technical-economic viability. To achieve this methodology, it was necessary to define parameters that influence directly or indirectly the size of a generating system, as the total electric demand of the filling station, ratio (power of the compressor) / (total installed power), load factor, factor of simultaneity, technical data of major equipment, among others. The methodology has been validated by comparing with data measured in a NGV filling station and allows screening and identifying customers with technical feasibility to evolve in a generation or cogeneration project. The cogeneration with NG generators was highlighted during the analysis of the NGV filling stations and was feasible for establishments which have large thermal demand, as filling stations along the road with large amounts of electric showers in changing rooms. (author)

  1. A human reliability analysis of the Three Mile power plant accident considering the THERP and ATHEANA methodologies; Uma analise da confiabilidade humana do acidente na Usina de Three Mile Island II considerando as metodologias Therp e Atheana

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Renato Alves da

    2004-03-15

    The main purpose of this work is the study of human reliability using the THERP (Technique for Human Error Prediction) and ATHEANA methods (A Technique for Human Error Analysis), and some tables and also, from case studies presented on the THERP Handbook to develop a qualitative and quantitative study of nuclear power plant accident. This accident occurred in the TMI (Three Mile Island Unit 2) power plant, PWR type plant, on March 28th, 1979. The accident analysis has revealed a series of incorrect actions, which resulted in the Unit 2 shut down and permanent loss of the reactor. This study also aims at enhancing the understanding of the THERP method and ATHEANA, and of its practical applications. In addition, it is possible to understand the influence of plant operational status on human failures and of these on equipment of a system, in this case, a nuclear power plant. (author)

  2. State variables applied in the analysis of transmission lines considering the influence of frequency on the longitudinal parameters; Variaveis de estado aplicadas na analise de linhas de transmissao considerando a influencia da frequencia nos parametros longitudinais

    Energy Technology Data Exchange (ETDEWEB)

    Monzani, R.C. [Universidade Estadual de Londrina (UEL), PR (Brazil). Centro de Tecnologia e Urbanismo. Dept. de Engenharia Eletrica; Prado, A.J.; Kurokawa, S.; Bovolato, L.F. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil). Fac. de Engenharia. Dept. de Engenharia Eletrica; Pissolato Filho, J. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Eletrica e Computacao. Dept. de Sistemas e Controle de Energia

    2009-07-01

    This paper presents a mathematical model to simulate and analyze time-domain electromagnetic transients in a transmission line using a single-phase representation of these lines with and without the influence of frequency on the longitudinal parameters. For this {pi} circuits and state variables are used to compose a linear system which is solved by a numerical routine. This routine is applied to the mathematical tool MatLab {sup TM} The aim of this paper is to demonstrate quickly and efficiently the study of electromagnetic waves to graduate students in Electrical Engineering, Computing and Mathematics courses, because EMTP (Electromagnetic Transient Program ) involve a greater complexity in handling which and can often lead disinterest in these individuals.

  3. Comparative analysis between horizontal and vertical heater treaters: identification and analysis of efficiency variables for oil treatment; Analise comparativa entre tratadores termicos horizontais e verticais: levantamento de variaveis criticas a eficiencia do processamento primario do oleo cru

    Energy Technology Data Exchange (ETDEWEB)

    Venancio, Fabricio de Queiroz; Ferreira, Doneivan Fernandes [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)

    2012-07-01

    The Brazilian onshore oil and gas production scenario has undergone changes with the maturity of fields and the prioritization of investments towards offshore projects. Added to the issue of lack of investment issue, the increasing production of formation water, which has already exceeded the production of the oil itself. With that comes the need to study the efficiency of process stages. It is common to find oil treatment plants (ETOS) limiting production operations due to lack of capacity to deal with increasing volumes of produced water. The critical moment of an ETO in onshore operations is the 'breaking' of emulsion (water in oil) usually performed by heater treaters. This article offers a comparative analysis between horizontal (TTH) and vertical (TTV) heater treaters, indicating the main variables and demonstrating opportunities for internalization of traditional and innovative technologies in horizontal systems that result in energy efficiency, optimization of the specification of oil (for marketing) and reduced operating costs. (author)

  4. Identification and analysis of local and regional impacts from the introduction of biodiesel production in the state of Piaui, Brazil; Identificacao e analise dos impactos locais e regionais da introducao da producao de biodiesel no estado do Piaui

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Omar Inacio Benedetti; Rathmann, Regis [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Planejamento Energetico; Padula, Antonio Domingos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2008-07-01

    The recent moves towards the insertion of biofuels in the energy matrix of a number of countries are opening new prospects for agricultural production and for agroindustrial chains. This study aims at understanding the mechanisms taking place within a production system geared towards biodiesel production. The emergence of this new productive base raises new research issues: in what circumstances are the structuring, organization and implementation of these biodiesel productive chains taking place in Brazil? What are the effects of biodiesel production on local economies? Hence, the central objective of this study is the development and validation of an analytical structure capable of characterizing the biodiesel productive arrangements and identifying their economic and social impacts at the regions where they are installed. A preliminary analysis identified that a biodiesel productive arrangement is emerging in the State of Piaui, Northeastern Brazil, Our theoretical basis comprises elements from the regional economy, biorefineries, local production arrangements and innovation. For the analyses, we employed the methods of input-output, local quotient and shift-share. It can be said that a new social-economic dynamics is taking place in Piaui; however, the company needs to assess its interaction with local institutions as well as its castor bean production strategies. (author)

  5. Gas pipeline crossings over water bodies: analysis of environmental impact mitigation coming from controls adopted; Implantacao de travessias de gasodutos em corpos d'agua: analise da mitigacao dos impactos ambientais decorrente das medidas de controle adotadas

    Energy Technology Data Exchange (ETDEWEB)

    Serricchio, Claudio; Caldas, Flaviana V. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Souza, Izabel C. de [TELSAN Engenharia e Servicos Ltda, Vitoria, ES (Brazil); Paz, Claudio [IMC Saste - Construcoes, Servicos e Comercio Ltda., Sao Paulo, SP (Brazil); Veronez, Fernanda A. [Centro Federal de Educacao Tecnologica do Espirito Santo (CEFET-ES), Vitoria, ES (Brazil)

    2008-07-01

    Among the implemented measures to control environmental impacts during the crossings of water courses, can be mentioned: the laying of pipe under provisional passages, the execution of physical barriers, the provisional and definitive drainage systems, the riverbank water bodies revegetation after the completion of works and the monitoring of water quality in the previous phases and after the execution of works for the implementation of the crossing. This study examined the effectiveness of these measures using as a case study the works of gas pipelines: Cacimbas (ES) - Vitoria (ES) and Cabiunas (RJ) - Vitoria (ES). In general it was observed that the measures taken were effective. In the case of implemented crossings with the conventional method of monitoring, the results confirmed an expected temporary increase in turbidity, resulting from the removal of sediment of the river bed in order to open the ditch. This impact was shown to be well tolerated by the body water, after crossing back to normal conditions. Regarding the Monitoring of Water Quality, which usually increases the cost of the venture, this was not an effective instrument for the control of impacts due to the time needed to obtain the results of samples taken compared to the time of execution of the crossing. (author)

  6. Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Alan Carlos Bueno da

    1997-07-01

    A heat transfer (condenser) of a domestic freezer was tested in a vertical channel in order to study the influence of the chimney effect in the optimization of the heat transfer coefficient. The variation of the opening of the channel, position and the heating power of the heat exchanger in the heat transfer coefficient was considered. The influence of the surface emissivity on the heat transfer by thermal radiation was studied with the heat exchanger testes without paint and with black paint. The air velocity entering the channel was measured with a hot wire anemometer. In order to evaluate the chimney effect, the heat exchanger was testes in a open ambient. This situation simulates its operational conditions when installed on the freezer system. The variables collected in the experimental procedures was gathered in the form of dimensionless parameters as Nusselt, Rayleigh, Grashof and Prandtl numbers, and dimensional parameters of the convection. The results showed that the highest heat transfer value occurred when both a specific position and a specific channel opening were used. The experiments pointed out that the radiation contribution must be considered in heat transfer calculations. The conclusions showed that different channel openings can improve the heat transfer coefficient in this heat transfer exchanger. (author)

  7. Comparative analysis of the cost of application for a blade of irrigation using electric energy and diesel; Analise comparativa do custo para aplicacao de uma lamina de irrigacao utilizando energia eletrica e diesel

    Energy Technology Data Exchange (ETDEWEB)

    Sa Junior, Arionaldo; Carvalho, Jacinto de Assuncao; Oliveria, Eduardo Carvalho de [Universidade Federal de Lavras (DEG/UFLA), MG (Brazil). Dept. de Engenharia], email: arionaldojr@hotmail.com

    2011-07-01

    The aim of this study was to estimate the cost of electric and diesel power for the application of 1 mm of irrigation in an area of 1 hectare. The Tariff Group considered was 'B' for low voltage and subgroup 'B2 Rural'. The fares used were obtained from CEMIG, being of R$ 0.22019. The diesel value adopted was the month of November 2010 in the southern region of Minas Gerais, comprising $ 1.97 L{sup -1}. For purposes of calculation, the total income of the height manometric were taken, respectively, 60%, 65%, 70%, 75% and 10, 25, 75, 100, 125, 150, 175 and 200 mca. To calculate the total cost with the application of the depth of 1mm was considered that the cost of energy accounts for 65% and 75% for electric and diesel, respectively. The results show a increase in energy costs by increasing the total head. The use of systems more efficient pump reduces the cost of electric power in the order of 6.7% to 20% and diesel from 3.6% to 16.2% for the proposed situations. In all cases the electric power is more appropriate with regard to cost. The relationship between electricity and diesel is 51.62% and 15.98% for better and worse, respectively. (author)

  8. Comparative analysis between the cost of energy for irrigation the production of Zoysia grass (Zoysia japonica Steud.); Analise comparativa entre os custos de energia na irrigacao para a producao da grama-esmeralda (Zoysia japonica Steud.)

    Energy Technology Data Exchange (ETDEWEB)

    Mazaroni, Bruno Henrique Silveira; Turco, Jose Eduardo Piteli; Coan, Ruchele Marchiori; Gerolineto, Eduardo [Universidade Estadual Paulista (FCAV/UNESP), Jaboticabal, SP (Brazil). Fac. de Ciencias Agrarias e Veterinarias. Dept. de Engenharia Rural

    2009-07-01

    This study analyzed the cost of energy (electrical and diesel) in the irrigated cultivation of zoysiagrass (Zoysia japonica Steud.) The research was conducted at Green-Park Farm, located in Pitangueiras, SP. It measured the consumption of diesel oil from a diesel engine, brand MWM, turbinate, 6 cylinder, and model D-229. The price of diesel oil was obtained from the Agencia Nacional do Petroleo (ANP). We studied the economic subtracting the result from the sale of zoysiagrass, the cost of consumption of diesel oil. It estimated the consumption of electric energy of a three-phase induction motor of 175 CV, WEG brand, coupled to a centrifugal pump Mark Peerless brand, model XHE-5A. To determine the energy expenditure was obtained the value of the rate with the Companhia Paulista de Forca e Luz (CPFL). A comparison of costs was performed by subtracting the economic result from the sale of grass in the cost of energy consumption. The 'Sistema Tarifario Grupo A Horo-Sazonal Verde e/ ou Azul', with special discount for irrigating at night was the lowest cost of electricity and by comparing the result of the economic costs of energy, the electrical system was more efficient in the use of fuel (diesel). (author)

  9. Analysis of electrical and microstructural characteristics of a ZnO-based varistor doped with rare earth oxide; Analise das caracteristicas microestruturais e eletricas de um varistor a base de ZnO dopado com oxidos de terras raras

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, J.M. de; Dias, R.; Furtado, J.G. de M. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil); Assuncao, F.C.R. [Pontificia Univ. Catolica do Rio de Janeiro (PUC/Rio), RJ (Brazil)

    2010-07-01

    Varistor is a semiconductor device, used in the protection of electrical systems, characterized to have a high no-linear electric resistance. Its properties are directly dependents of its chemical composition and microstructural characteristics. In this work were analyzed microstructural and electrical characteristics of a ZnO-based varistor doped with rare earth oxide, with chemical composition (mol%) 98,5.ZnO - 0,3.Pr{sub 6}O{sub 11} - 0,2.Dy{sub 2}O{sub 3} - 0,9.Co{sub 2}O{sub 3} - 0,1.Cr{sub 2}O{sub 3}. X-ray diffraction for phase characterization, scanning electron microscopy and energy dispersive X-ray spectroscopy were used for microstructural analysis. Measurement of average grain size and electrical and dielectric characteristics complete the characterization. The results show the formation of biphasic microstructure and with high densification, presenting relevant varistors characteristics but that would need improvements.(author)

  10. Social-environmental fragility analysis for diagnosis of watershed in study of hydroelectric projects; Analise de fragilidade socioambiental para o diagnostico de bacias hidrograficas no estudo de empreendimentos hidreletricos

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Jonas Fernandes; Dzedzej, Maira [IX Consultoria e Representacoes Ltda, Itajuba, MG (Brazil); Oliveira, Samuel Torres de; Flauzino, Barbara [IX Consultoria e Representacoes Ltda, Itajuba, MG (Brazil); Universidade Federal de Itajuba, (UNIFEI), MG (Brazil)

    2010-07-01

    This paper presents a methodology for assessing the social-environmental fragility of a watershed where there is potential for installation of hydropower projects. The method includes dividing the watershed into sub areas (by analysis of similar characteristics) and, subsequently, the use of 23 indicators grouped into six social-environmental components (Water Resources and Aquatic Ecosystems, Terrestrial Ecosystems and the Physical Environment, Territorial Organization, Way of Life, Economic Base and Indigenous Communities and Traditional Populations), which together seek to portray all aspects involved in the fragility of the area. The technique was applied in the basin of the Coxim river in the State of Mato Grosso do Sul, assuming that there is interest or the possibility of installing hydropower plants within its boundaries. The basin was divided into three sub areas, considering physical parameters (such as topography, rainfall and hydrology), which were ranked by calculating the fragility of each one of the social-environmental indicators. As a result, a map was created to indicate the sub areas more susceptible to damage and those which should be more resistant to the installation of impacting activities, such as hydropower plants. The use of Geographic Information Systems (GIS) and the work of a multidisciplinary team can reduce the degree of subjectivity of the methodology and allow, (by modifying some considerations inherent in the partial calculations,) its application in other situations where the possibility of installing hydropower projects is not considered. (author)

  11. Review of the sustainability of the forest sector to produce charcoal from planted forests; Analise da sustentabilidade do setor florestal para producao de carvao vegetal a partir de florestas plantadas

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Thiago Oliveira [Fundacao de Tecnologia Florestal e Geoprocessamento (NUPA/FUNTEC), Brasilia, DF (Brazil). Nucleo de Projetos Ambientais

    2008-07-01

    Brazil is the world's greater producer of charcoal and most of this production takes care of to the siderurgical sector. Thus, one understands that the Brazilian steel is produced of sustainable form. However, such sustainability is not based only on a renewable energy source. The origin of the wood for the carbonization, if proceeding from planted forests or native bushes, is crucial factor in this analysis. Beyond the ambient dimension, the sustainability of the charcoal segment also is influenced by its social, economic and technological aspects. In this context, the present article searches, through the construction and the analysis of the diagnosis of the charcoal in Brazil, to evaluate the sustainability of the sector and to consider alternatives to reach it. The current model of production of charcoal in the country is unsustainable. The main adopted systems of carbonization in Brazil are low level technological with consequent decrease production. The activity is unhealthy, beyond having many cases of enslaved and infantile work. The coal of native forests is much cheaper and the fiscalization is poor, fact that discourages its production from planted forests. But if the vegetal coal will be understood as an energy solution for the siderurgical sector measures can be taken to search a model of sustainable production. (author)

  12. Peru and Brazil: a comparative analysis of E and P licensing models adopted by these countries; Peru e Brasil: um analise comparativa dos modelos de licitacao de E and P adotados por esses paises

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Luciana P; Ferreira, Sabrina S [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work presents a comparative analysis of the concession process of Oil and Gas Exploratory Blocks adopted in two countries of Latin America: Peru and Brazil, according to the rules of the Bidding Rounds occurred in 2007 (Peru's Bidding Round and 9th Bidding Round, respectively). In order to analyze the two models chosen, we considered, among others, the rules and proceedings adopted, the legal framework, the criteria used to qualify the companies, the number of blocks offered, the number of participating companies, the infra-structure of the event and the offer selection system. Through this analysis it was possible to verify the points which could be improved in each concession process model and it showed significant differences between them, despite the fact of each one is suitable to the reality of each country. It is important to highlight that the exchange of experience between agents of oil and gas sector, in this specific case Perupetro and ANP, contributes a lot to the continued improvement of bidding processes and other practices adopted. (author)

  13. Peru and Brazil: a comparative analysis of E and P licensing models adopted by these countries; Peru e Brasil: um analise comparativa dos modelos de licitacao de E and P adotados por esses paises

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Luciana P.; Ferreira, Sabrina S. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work presents a comparative analysis of the concession process of Oil and Gas Exploratory Blocks adopted in two countries of Latin America: Peru and Brazil, according to the rules of the Bidding Rounds occurred in 2007 (Peru's Bidding Round and 9th Bidding Round, respectively). In order to analyze the two models chosen, we considered, among others, the rules and proceedings adopted, the legal framework, the criteria used to qualify the companies, the number of blocks offered, the number of participating companies, the infra-structure of the event and the offer selection system. Through this analysis it was possible to verify the points which could be improved in each concession process model and it showed significant differences between them, despite the fact of each one is suitable to the reality of each country. It is important to highlight that the exchange of experience between agents of oil and gas sector, in this specific case Perupetro and ANP, contributes a lot to the continued improvement of bidding processes and other practices adopted. (author)

  14. Evaluation of internal occupational exposure of workers from nuclear medicine services by aerosol analysis containing {sup 131}I; Avaliacao da exposicao interna de trabalhadores em servicos de medicina nuclear atraves da analise de aerossois contendo {sup 131}I

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Luana Gomes; Sampaio, Camilla da Silva; Dantas, Ana Leticia Almeida; Lucena, Eder Augusto; Santos, Maristela Souza; Dantas, Bernardo Maranhao, E-mail: carneiro@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ),Rio de Janeiro, RJ (Brazil); Paula, Gustavo Affonso de [Escola SESC de Ensino Medio, Rio de Janeiro, RJ (Brazil)

    2014-07-01

    This study evaluated the risk of internal occupational exposure associated with the incorporation of {sup 131}I via inhalation, in Nuclear Medicine Services, using aerosol analysis techniques. Occupationally Exposed Individuals (IOE) involved in handling this radionuclide are subject to chronic exposure, which can lead to an increase in the committed effective dose. Results obtained in preliminary studies indicate the occurrence of incorporation of {sup 131}I by workers involved in handling solutions for radioiodine therapy procedures. The evaluation was carried out in radiopharmacy lab (nuclear medicine service) of a public hospital located in the city of Rio de Janeiro. After confirmed the presence of the radioisotope, by a qualitative assessment, it was determined an experimental arrangement for sample collection and were detected and quantitated the presence of steam {sup 131}I during routine work. The average concentration of activity obtained in this study was 3 Bq / m{sup 3}. This value is below of Derived Concentration in Air (DCA) of 8.4 x 10{sup 3} Bq of {sup 131}I / m{sup 3} corresponding to a committed effective dose of 1.76 x 10{sup -4} mSv. These results demonstrate that the studied area is safe in terms of internal exposure of workers. However, the presence of {sup 131}I should be periodically reevaluated, since this type of exposure contributes to the increase of the individual effective doses. Based on the data obtained improvements were suggested in the exhaust system and the use of good work practices in order to optimize the exposures.

  15. Construction of scientific production indicators based on scientometrics analysis of IPEN dissertations and theses; Elaboracao de indicadores de producao cientifica com base na analise cientometrica das dissertacoes e teses do IPEN

    Energy Technology Data Exchange (ETDEWEB)

    Igami, Mery Piedad Zamudio

    2011-07-01

    Construction of Indicators plays an important role in the contemporaneous society. It could be observed their ordinary use by all the activities segments. In scientific area it is not different; such practice has already been consolidated; this statement could be corroborated by the innumerous papers published about this matter in the main databases; however, there is a prevalence of quantitative studies, which obtain data from the international databases, analyzing journal articles. Concerning this finding, the main objective of this study was to elaborate scientific indicators from a local institutional data base, using as a corpus of the study the dissertations and theses, produced by a graduate program in the period of 1977 to 2009.Three types of two-dimensional indicators were obtained by using bibliometric techniques: numerical, thematic and productivity. For dissertations and theses thematic characterization it was used the Subject categories and scope descriptions and the International Nuclear Information System Thesaurus (INIS). Through the statistical technique of clustering analysis, it was possible to classify them in five main groups, showing former performance and growth future trends of each group; for data extraction about theses productivity, regarding articles published; the Curriculo Lattes, and the local institutional database were used. Co-word analysis technique was used to establish a more precise correlation, between articles and theses, and for this purpose it was used the keywords from a controlled vocabulary. In order to validate the results, it was performed a survey, with the theses authors. Results obtained indicated that 55.9% of the articles published, between 5 years, before and after the thesis presentation, are strongly correlated to it. It was also observed that, correlated articles have been published, in an average of, 1, 63 year before the thesis presentation. Concerning databases, it was shown that they are valuable tools and

  16. Neutron activation analysis applied to the determination of trace elements in human nails; Aplicacao do metodo de analise por ativacao com neutrons a determinacao de elementos traco em unhas humanas

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Amilton Reinaldo

    2001-07-01

    There is a considerable interest in the determination of trace elements in human nails in order to use this tissue as a monitor of nutritional and healthy status of individuals, of occupational exposure diseases and of the environmental contamination. In this work, instrumental neutron activation analysis was applied to determine trace elements in finger nail clippings to make comparisons between the elemental concentrations obtained in nails from healthy individuals of a control group and those from cystic fibrosis (CF) patients. Firstly, a protocol for sample collection and preparation for analysis was established. Finger and toe nail samples from CF patients were collected at the Instituto da Crianca of Medicine School, University of Sao Paulo, SP. The nail samples from control group were collected from healthy adults and from children living in Sao Paulo city, SP. These samples were cleaned by stirring them witha a diluted Triton X100 solution and then by washing with distilled water and acetone. The analytical procedure consisted of irradiation nail samples and elemental standards in the IEA-R1m nuclear reactor under thermal neutro flux of about 10{sup 12} n cm{sup -2} s{sup -1}, for short and long period irradiations. The activities of the radionuclides were measured using a gamma-ray spectrometer comprising an hyperpure Ge detector and associated electronic system. The biological reference materials Bovine Liver 1577b and Oyster Tissue 1566a, both from National Institute of Standards and Technology, USA were analysed in order to evaluate the accuracy and precision of the results. The analysis of variance (ANOVA) and F-test at the significance level of 5% were used to make a comparison between the sets of results obtained in this work. In the comparison of the results obtained for finger and toe nails from CF patients, the Br concentrations were higher in finger nails that those obtained for toe nails. For the control group of children, the finger nails

  17. Cooling high heat flux micro-electronic systems using refrigerants in high aspect ratio multi-microchannel evaporators

    International Nuclear Information System (INIS)

    Costa-Patry, E.

    2011-11-01

    Improving the energy efficiency of cooling systems can contribute to reduce the emission of greenhouse gases. Currently, most microelectronic applications are air-cooled. Switching to two-phase cooling systems would decrease power consumption and allow for the reuse of the extracted heat. For this type of application, multi-microchannel evaporators are thought to be well adapted. However, such devices have not been tested for a wide range of operating conditions, such that their thermal response to the high non-uniform power map typically generated by microelectronics has not been studied. This research project aims at clarifying these gray areas by investigating the behavior of the two-phase flow of different refrigerants in silicon and copper multi-microchannel evaporators under uniform, non-uniform and transient heat fluxes operating conditions. The test elements use as a heat source a pseudo-chip able to mimic the behavior of a CPU. It is formed by 35 independent sub-heaters, each having its own temperature sensor, such that 35 temperature and 35 heat flux measurements can be made simultaneously. Careful measurements of each pressure drop component (inlet, microchannels and outlet) found in the micro-evaporators showed the importance of the inlet and outlet restriction pressure losses. The overall pressure drop levels found in the copper test section were low enough to possibly be driven by a thermosyphon system. The heat transfer coefficients measured for uniform heat flux conditions were very high and typically followed a V-shape curve. The first branch was associated to the slug flow regime and the second to the annular flow regime. By tracking the minimum level of heat transfer, a transition criteria between the regimes was established, which included the effect of heat flux on the transition. Then for each branch, a different prediction method was used to form the first flow pattern-based prediction method for two-phase heat transfer in microchannels. A

  18. Steam-based Charging-Discharging of a PCM Heat Storage

    African Journals Online (AJOL)

    fire7-

    2016-11-10

    Nov 10, 2016 ... 2Department of Energy and Process Engineering, Norwegian University of Science and. Technology ... Keywords: Solar energy, PCM storage, Latent heat storage, Two-phase thermosyphon. 1. ..... principle, with water as the working fluid at about 35-bar pressure. ... generator as applied to PTC systems.

  19. Stage of GAN (Grupo de Analise do Nucleo) calculus methodology

    International Nuclear Information System (INIS)

    Silva, C.F. da.

    1987-11-01

    This Technical Note presents the stage of GAN Calculus Methodology in areas of Neutronics, Fuel Rod Performance and Fission Products Inventory. Proposals of GAN's members are presented and analyzed for each of these areas and a work schedule is established. (author)

  20. New perspectives towards analising fungal communities in terrestrial environments

    NARCIS (Netherlands)

    Kowalchuk, G.A.

    1999-01-01

    Fungi play key roles in numerous ecosystem functions, and recent advances in the study of fungal diversity and ecology have led to a greater appreciation of this group of microeukaryotes. The application of a variety of nucleic acid techniques to fungal classification and phylogeny has led to a

  1. Demanda dos principais metais e novos materiais : analise de tendencias

    OpenAIRE

    Wilson Trigueiro de Sousa

    1990-01-01

    Resumo: Neste trabalho são analisadas algumas tendências na área de novos materiais na tentativa de obter um melhor entendimento das repercussões das atuais inovações tecnológicas para o setor mineral. Inicialmente são revisados os principais estudos sobre as mudanças ocorridas por volta de 1972/74 no comportamento da demanda dos metais mais importantes. Entre as possíveis causas, está o progresso técnico, que tornou possível o surgimento de novos materiais e o aperfeiçoamento de outros em us...

  2. Thermal and hydrodynamic characteristics of supercritical CO2 natural circulation in closed loops

    International Nuclear Information System (INIS)

    Chen, Lin; Deng, Bi-Li; Jiang, Bin; Zhang, Xin-Rong

    2013-01-01

    Highlights: ► We model thermosyphon heat transfer and stability with super-/trans-critical turbulence model incorporated. ► Potentials of super-/trans-critical CO 2 thermosyphon are confirmed. ► Three characteristics found: flow instability; high flow rate with density wave; heat transfer discrepancies. ► Major laws of system stability factors are different compared with traditional fluids. ► Traditional thermosyphon flow correlation has its limitations and deserves further development. -- Abstract: Natural convective flow of supercritical fluids has become a hot topic in engineering applications. Natural circulation thermosyphon using supercritical/trans-critical CO 2 can be a potential choice for effectively transportation of heat and mass without pumping devices. This paper presents a series of numerical investigations into the fundamental features in a supercritical/trans-critical CO 2 based natural circulation loop. New heat transport model aiming at trans-critical thermosyphon heat transfer and stability is proposed with supercritical/trans-critical turbulence model incorporated. In this study, the fundamentals include the basic flow and heat transfer behavior of the above loop, the effect of heat source temperature on system stability, the effect of loop diameter on natural convection supercritical CO 2 loop and its coupling effect with heat source temperature and the effect of constant changing heat input condition and system behavior evolution during unsteady input or failure conditions. The fundamental potentials of supercritical/trans-critical CO 2 based natural convection system are confirmed. Basic supercritical CO 2 closed loop flow and heat transfer behaviors are clarified. During this study, the CO 2 loop stability map are also put forward and introduced as an important feature of supercritical CO 2 system. Stability factors of natural convective trans-critical CO 2 flow and its implications on real system control are also discussed in

  3. Analysis of the legal aspects in public tender electronic made by PETROBRAS through the system Petronect under Decree no. 2.745/98; Analise da juridicidade das licitacoes eletronicas feitas pela PETROBRAS atraves do sistema Petronect nos termos do decreto 2.745/98

    Energy Technology Data Exchange (ETDEWEB)

    Prestes, Madelon Rocha Ribeiro [Transportadora Brasileira Gasoduto Bolivia-Brasil S.A. (TBG), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work examines the question of possible of use an electronic tool through internet, the Petronect, to facilitate the completion of procedures to carry through licitations for the PETROBRAS Group that is being debated in diverse instances in the Brazilian present time. This analysis should take into account the existing law on licitations, the constitutionality of Decree 2.745/98, as well as economic facts. Due to the understanding of TCU - expressed on several occasions - in the sense that PETROBRAS would be required to use the Law 8.666/93 in its bids, is being challenged the constitutionality of Decree 2.745/98 and their use for licitations procedures. They will be examined the conceptual and legal aspects of the decree, and the relationship and the importance of the function for the Group Purchases damage. Thus, the analysis will cover the new issues raised by EC 19/98, the constitutionality of the decree, the position of the Court of Auditors of the Union and the Federal Supreme Court (STF) and the legislation published on this subject. The existing conclusion in this work shows how right - under the optical legal and constitutional - the use of the portal Petronect to carry out the licitations of PETROBRAS under Decree 2.745/98 and non-use of Law 8.666/93, for this is not appropriate to the specific activity of company. (author)

  4. The oil potential of the BM-J-2 block, Jequitinhonha basin, Brazil: the integrated study of the basin analysis and modeling of petroleum system; Potencial petrolifero do Bloco BM-J-2, Bacia de Jequitinhonha, Brasil: um estudo integrado de analise de bacia e modelagem de sistemas petroliferos

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Roberto; Braga, Jose A.E.; Saito, Makoto; Cortez, Marcella; Ponte Filho, Francisco C.; Romao, Felipe [Queiroz Galvao Perfuracoes S.A., Rio de Janeiro, RJ (Brazil); Goncalves, Felix T.T. [PGT-Petroleum Geoscience Technology Ltd., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The integration of all available geochemical data from this and adjoining blocks (BM-J-1 e BM-J-3) Jequitinhonha Basin revealed that only the Albian-Turonian and Aptian sections contains potential hydrocarbon source rock intervals. The existence of an oil accumulation (1-BAS-37) represents an unequivocal evidence of the presence of effective source rocks in the Jequitinhonha Basin. The geochemical characteristics of this oil accumulation points to an origin related to petroleum source rocks deposited under a lacustrine/marine restricted (hyper saline) environment. Such characteristics are typical of pre-salt Aptian source rocks in several basins along the Brazilian margin. The pseudo-3D modeling results indicate that the stage of thermal evolution of the base of the rift section attained ranges from early mature (0.6-0.8 Ro) in the structural highs to over mature (up to 2.0% Ro) in the structural lows On the other hand, the potential sources rocks of Albian-Turonian age ranges to immature to early mature throughout the block. The modeling results also points to the existence of two distinct hydrocarbon 'kitchens': one located in the easternmost portion of the block (slope/deep water area) and the other in a structural low located in the shallow platform area. The main phase of petroleum expulsion ranged from Late Cretaceous/Paleogene in the platform area. Probabilistic simulations has estimated migrated oils and gas volumes around 507 MMbbl and 20 billion cubic meters, respectively. (author)

  5. Analysis of the perception of risk of radiotherapy services in the metropolitan region of Rio de Janeiro using the risk evaluation system in radiotherapy (SEVRRA / FORUM); Analise da percepcao de risco de servicos de radioterapia da regiao metropolitana do Rio de Janeiro usando o sistema de avaliacao de risco em radioterapia (SEVRRA/FORO)

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Adam de Freitas

    2015-07-01

    In this work it was possible to analyze the perception of risks associated with existing processes in the high-dose rate brachytherapy and teletherapy using linear accelerators of radiotherapy services in the metropolitan area of Rio de Janeiro, through the combined use of two proposed methods: FMECA and risk matrix, using a general analysis and other more specific ones. The database software (SEVRRA) was used to identify possible existing processes in radiotherapy services (brachytherapy and teletherapy) and to classify the sequence of events in risk levels. The risk levels were analyzed at each stage and sub-stage, present in the treatment of patients undergoing high dose rate gynecological intracavitary brachytherapy and teletherapy treatments with the use of linear accelerators applying electron or photon beams in order to establish recommendations to the risks of highest priority for each case. The results show that although the procedure of high dose rate brachytherapy be automated and less susceptible to errors or failures, daily, one can still find considerable amounts of processes with worrying levels of risk perception. The processes that are more subject to radiological accident risks was associated with procedures, for of which the majority of the failures record and planning step of the treatment. The controls analyzed showed low efficiency, warning of the need to seek and implement new more efficient controls in routine brachytherapy for each participant service. About teletherapy procedure it was found that most of the failures were related to the registration and planning of treatment and equipment stages. The controls analyzed to teletherapy showed a poor result with a first type of analysis performed by suggesting a new type of more appropriate analysis. With a second type of analysis, these controls could be better analyzed and showed an order of importance according to a percentage of efficiency. Controls such as 'Double-check', 'Weekly image portal' and 'Weekly medical review of patients', were highlighted as the most present and effective in routine radiotherapy procedure. These results have great relevance for this type of methodology, since their practical application, together with its potential risk identification and classification, confirm their feasibility of use in routine services in the metropolitan area of Rio de Janeiro, as well as in other locations, seeking to meet national and international recommendations for safety and radiation protection. (author)

  6. Preliminary analysis for implementation of a hybrid solar-wind system with storage of electrical energy generated through electrolytic hydrogen and fuel cells; Analise preliminar para implementacao de um sistema hibrido solar-eolico com armazenamento da energia eletrica gerada atraves de hidrogenio eletrolitico e celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Daniel Gabriel; Furlan, Andre Luis; Lopes, Davi Gabriel [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica], e-mail: danielg@fem.unicamp.br; Silva, Ennio Peres; Apolinario, Fernando Resende [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Lab. de Hidrogenio; Silva, Maria Eugenia Vieira da; Rocha, Paulo Alexandre Costa [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Mecanica e de Producao; Codeceira Neto, Alcides [Companhia Hidro Eletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    Due to relevance of the study and applicability of hybrid electric power generation from solar photovoltaic and wind power in Brazil, the present paper aims to introduce briefly the importance of technical and economic comparison of two electrical energy storage technologies (batteries versus H2 + fuel cell) and also to indicate the previous difficulties related to this possible application. In this context, it was intended a partnership between State University of Campinas - UNICAMP, the Federal University of Ceara - UFC and Hydro Electric Company of the Sao Francisco - CHESF in the meaning of makes viable an implementation. (author)

  7. Analysis of two technological systems for broiler chickens production with emphasis in a rational use of electric energy and animal productivity; Analise de dois sistemas tecnologicos de producao de frango de corte com enfase no uso racional de energia eletrica e produtividade animal

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Leda Gobbo de Freitas; Rossi, Luiz Antonio [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Agricola. Construcoes Rurais e Ambiencia], e-mail: leda.bueno@agr.unicamp.br, e-mail: rossi@agr.unicamp.br

    2004-07-01

    The creation of broiler intensely depends on electric energy for maintenance of the thermal comfort, automation, and optimize the production and animal productivity. The goal of this research was to quantify and to characterize the electric energy have been used in two commercial sheds of broiler. It was examined the variable concerned to the electric energy (energy efficiency, consumption, demand and factor of power) and the main variable related to the animal productivity (gain of weight, alimentary conversion and mortality). It was analyzed the use of electric energy to keep both the ideal thermal comfort and to observe the broiler productivity performance. The period of the experiment was two years and was considered five lots of creation in different seasons of the year. (author)

  8. Engineering Design Elements of a Two-Phase Thermosyphon to Trannsfer NGNP Nuclear Thermal Energy to a Hydrogen Plant

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwal

    2009-07-01

    Two hydrogen production processes, both powered by a Next Generation Nuclear Plant (NGNP), are currently under investigation at Idaho National Laboratory. The first is high-temperature steam electrolysis, which uses both heat and electricity; the second is thermo-chemical production through the sulfur iodine process primarily using heat. Both processes require a high temperature (>850°C) for enhanced efficiency; temperatures indicative of the NGNP. Safety and licensing mandates prudently dictate that the NGNP and the hydrogen production facility be physically isolated, perhaps requiring separation of over 100 m.

  9. A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

    Directory of Open Access Journals (Sweden)

    Á. Marroquín de Jesús

    2009-07-01

    Full Text Available Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled type, the other one flat, which are joined by electric welding. The absorber is connected to a 198–L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m2, about 20% smaller than comparable copper–tube–based collectors offered in the market. Temperature measurements conducted over a 30–day period gave values which were a few degrees lower than the theoretically calculated water temperatures. Momentary thermal efficiency values between 35% and 77% were observed. The water temperature achieved in the tank at the end of the day aver ages 65°C in winter weather conditions in the central Mexican highland. This design of solar water heater is well suited to Mexican conditions, as it makes use of the high local intensity of the solar radiation, and as the channel shape of the ducts minimizes bursting during the rare occurrences of freezing temperatures in the region; it also has the advantage of being manufacturable at low cost from simple materials.

  10. A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

    OpenAIRE

    Marroquín de Jesús, Á.; Olivares-Ramírez, J.M.; Ramos-López, G.A.; Pless, R.C.

    2009-01-01

    Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled type, the other one flat, which are joined by electric welding. The absorber is connected to a 198-L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m², about 20% smaller than ...

  11. A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

    OpenAIRE

    Á. Marroquín de Jesús; J.M. Olivares–Ramírez; G.A. Ramos–López; R.C. Pless

    2009-01-01

    Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled type, the other one flat, which are joined by electric welding. The absorber is connected to a 198–L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m2, about 20% smaller than ...

  12. Thermic diode performance characteristics and design manual

    Science.gov (United States)

    Bernard, D. E.; Buckley, S.

    1979-01-01

    Thermic diode solar panels are a passive method of space and hot water heating using the thermosyphon principle. Simplified methods of sizing and performing economic analyses of solar heating systems had until now been limited to passive systems. A mathematical model of the thermic diode including its high level of stratification has been constructed allowing its performance characteristics to be studied. Further analysis resulted in a thermic diode design manual based on the f-chart method.

  13. Organization of health care for the patients with benign diseases: the problem of one-day hospitalization

    Directory of Open Access Journals (Sweden)

    L. V. Kochorova

    2013-01-01

    Full Text Available The article analises the volume of medical care to the citizens of St. Petersburg, suffering with benign diseases and hospitalized for one day. It is shown,that the level of one-day hospitalization is a marker of not approved hospitalization and unreasonable spending of funds in the state system of obligatory insurance.

  14. Analysis of loss of electrical power with the CATHENA model of the blanket and first wall cooling loop for the SEAFP reactor design

    International Nuclear Information System (INIS)

    Ross, W.E.

    1994-08-01

    This report documents the thermosyphoning analysis which was performed with the CATHENA network model of one of the blanket and first wall cooling loops of the SEAFP reactor design. This thermosyphoning analysis is similar to that reported in CFFTP-G--9355, Volume 4 except that a much larger decay power transient is used. Also, the pressurizer heaters are turned off following the loss of electrical power. This analysis is performed to assess the primary heat transport system behaviour for a complete loss of electrical power event (total loss of flow) and to estimate the rate of heatup of the in-core components. A description of the important aspects of the transient thermalhydraulic behaviour including coolant temperatures, circuit and sector flows, circuit pressure, pressurizer level and steam bleed flow, and first wall and blanket temperatures are provided. (author). 8 refs., 2 tabs., 26 figs

  15. Absorption cycle commercial refrigerator using wood burning cook stove; Geladeira de absorcao acionada por fogao a lenha

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Jose Tomaz Vieira; Martins, Gilberto [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia

    1991-12-31

    The current utilization of wood burning cook stoves in Brazil and the socio-economical profile of their users were surveyed. A traditional heavy-mass wood-burning cook stove was studied as a thermal equipment. Simple changes in the geometry of the combustion chamber were suggested to improve the cooking efficiency. A closed two-phase thermosyphon using water as working fluid was designed, built and connected between the combustion chamber of the cook stove and a depressurized absorption refrigeration system to determine the heat flux and the temperature level. A commercial refrigerator unit, using the absorption cycle, was coupled with the wood stove through the thermosyphon. The overall results of the coupling point to successful country-side applications. (author) 12 refs., 9 figs., 4 tabs.

  16. Heating Performance Study on a Passive Solar Heater

    Directory of Open Access Journals (Sweden)

    Naz Muhammad Y.

    2017-01-01

    Full Text Available A passive thermosyphon heating system was designed, fabricated and tested for its thermal performance in semi-arid and four-season climate of Pakistan. The heating system design was based on a two-stage storage and natural thermosyphon circulation of the water. The objective of the study was to enhance the heating performance of the thermosyphon systems by using a semicircular steel pot collector, water carrying copper coil cover, two step water storage, and side mirror reflectors. The experiments were conducted during April to July 2014 when ambient temperature was reported to vary between 32°C and 44°C. In continuous flow mode operation, the hot water temperature remained between 46°C and 78°C. Since water temperature in the range of 45°C to 50°C is considered suitable for the domestic use, the presented design can easily reach the temperatures even higher than those acceptable for the domestic use.

  17. Analysis of minor incidents in the operation of nuclear power plants: a case study on the use of procedures in organizations dealing with hazardous technologies; Analise de microincidentes na operacao de usinas nucleares: estudo de caso sobre o uso de procedimentos em organizacoes que lidam com tecnologias perigosas

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Paulo Victor Rodrigues de [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], e-mail: paulov@ien.gov.br; Vidal, Mario Cesar Rodriguea [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Grupo de Ergonomia e Novas Tecnologias (GENTE); Carvalho, Eduardo Ferro de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Engenharia de Producao

    2005-05-15

    Organizations that work with hazardous materials, such as nuclear power plants, offshore installations, and chemical and petrochemical plants, have risk management systems involving accident control and mitigation to ensure the safety of their facilities. These systems are based on physical devices, such as protective barriers, equipment and systems aimed at preventing the occurrence and propagation of accidents, and on human aspects such as regulations and procedures. This paper analyzes the use of a variety of procedures by nuclear power plant control room operators. The methodology consisted of analyzing the work of control room operators during the normal operations, shutdown, and startup of a nuclear power plant, and in full scale simulator training. This survey revealed that routine noncompliance to procedures was considered normal according to the operating rationale, which is based on technical, organizational and cultural factors. These findings indicate that the competencies nuclear power plant operators must possess far exceed proper technical training and the ability to follow written instructions. (author)

  18. Analysis & Tools to Spur Increased Deployment of “Waste Heat” Rejection/Recycling Hybrid Ground-source Heat Pump Systems in Hot, Arid or Semiarid Climates Like Texas

    Energy Technology Data Exchange (ETDEWEB)

    Masada, Glenn [Univ. of Texas, Austin, TX (United States); Moon, Tess [Univ. of Texas, Austin, TX (United States)

    2013-09-01

    This project team analyzed supplemental heat rejection/recovery (SHR) devices or systems that could be used in hybrid ground source heat pump (HGHP) systems located in arid or semi-arid regions in southwestern U.S. Identification of effective SHR solutions would enhance the deployment of ground source heat pumps (GHP) in these regions. In a parallel effort, the team developed integrated GHP models that coupled the building load, heat pump, and ground loop subsystems and which could be applied to residential and commercial office buildings. Then GHP and HGHP performances could be compared in terms of operational performance and life-cycle costs. Several potential SHR devices were analyzed by applying two strategies: 1) to remove heat directly from the water in the ground loop before it enters the ground and 2) to remove heat in the refrigerant loop of the vapor compression cycle (VCC) of the heat pump so less heat is transferred to the water loop at the condenser of the VCC. Cooling towers, adsorption coolers, and thermoelectric liquid coolers were included in strategy 1, and expanded desuperheaters, thermosyphons, and an optimized VCC were included in strategy 2. Of all SHR devices analyzed, only the cooling tower provided a cost-effective performance enhancement. For the integrated GHP model, the project team selected the building load model HAMBASE and its powerful computational Simulink/MatLab platform, empirical performance map models of the heat pumps based upon manufacturers’ performance data, and a ground loop model developed by Oklahoma State University and rewritten for this project in Simulink/MatLab. The design process used GLHEPRO, also from Oklahoma State University, to size the borehole fields. The building load and ground loop models were compared with simulations from eQuest, ASHRAE 140-2008 standards, EnergyPlus, and GLHEPRO and were found to predict those subsystems’ performance well. The integrated GHP model was applied to a 195m2

  19. Stratigraphic analysis and geodynamic evolution of the 'Transitional Sequence' in the southern Sergipe-Alagoas Basin; Analise estratigrafica e evolucao geodinamica da 'Sequencia Transicional' na porcao sul da Bacia de Sergipe-Alagoas

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Liliane Rabelo [Petrobras, Natal/Fortaleza, RN/CE (Brazil). Unidade de Operacoes de Exploracao e Producao. Avaliacao de Blocos e Interpretacao Geologica e Geofisica], E-mail: lilianerabelo@petrobras.com.br; Cordoba, Valeria Centurion; Sa, Emanuel Ferraz Jardim de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Ciencias Exatas e da Terra. Programa de Pos-Graduacao em Geodinamica e Geofisica], Emails: valeria.geo@ufrnet.br, emanuel@ccet.ufrn.br

    2009-11-15

    This paper presents a stratigraphic analysis and considerations about the tectonic activity and subsidence processes that controlled the deposition of the 'Transitional Sequence' in the Sergipe Sub-basin (SBSE), southern Sergipe-Alagoas Basin, during the Neoaptian (upper Alagoas), the transition between the rift and drift stages in this basin. The stratigraphic analysis of selected wells led to the recognition of five third order depositional sequences, that were deposited in decreasing conditions of water circulation, from continental siliciclastic systems to lagoonar-evaporitic systems and, finally, to restricted marine systems, indicating an increase of the base level. In terms of a second order cycle, the 'Transitional Sequence' represents the deposition in a stage of base-level rise and the beginning deposition of a transgressive system tract, whose transition to the overlying marine transgressive sequence is marked by flooding. In terms of a third order cycle, this transition is marked by a local unconformity, which laterally changes to a correlative conformity. Such unconformity is interpreted as a breakup unconformity, of pre-Albian age in the SBSE, contrasting with the more expressive (especially for its angular character) of the Pre-Upper Alagoas Unconformity (DPAL), at the base of the 'Transitional Sequence', frequently regarded in the literature as the breakup unconformity. Even though, the Pre-Albian Unconformity is here favoured as the major change in depositional context and tectonic environment (rift to drift) in the SBSE. The deposition of the 'Transitional Sequence' occurred close to the end of the Rifting Stage, with an epicontinental sea advancing along a segment of continental crust still in extension, controlled by a combination of thermal and mechanical subsidence, the latter already in pronounced decline. (author)

  20. Analysis of mercury and selenium in biological samples by neutron activation analysis; Analise de mercurio e selenio em materiais biologicos pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Catharino, Marilia Gabriela Miranda

    2002-07-01

    In the present work, hair samples from populations suspected of contamination by mercury, in the localities of Serra do Navio, Vila Nova and Tartarugalzinho, in the State of Amapa, were analyzed. Hair samples of children under odontopediatric treatment were also analyzed for mercury, in order to study the possibility of transfer of mercury from the dental amalgam and also to obtain data of hair mercury in a control population of children. Another step of the work was the development of a method for the determination of selenium, by using the short-lived radioisotope {sup 77}mSe. After the certification of the method it was applied to the analysis of hair, nails and a vitamin supplement. A comparison was made with the results obtain ed by using the long-lived radioisotope of selenium, {sup 75}Se. The results obtained for mercury in the hair samples of populations living in the State of Amapa have shown that the mercury concentrations in these populations are much higher than in the controls. As for the hair samples of children under treatment with mercury amalgam, no significant differences were found in the concentrations of mercury after the treatment. On the other hand, these data were important to obtain data for a control population of children. The results obtained by using the radioisotope {sup 77}mSe showed that the method developed was suitable for the analyzed matrixes and the results were similar to the ones obtained by employing the usual AANI method, with the radioisotope {sup 75}Se. (author)

  1. Gastrointestinal parasites occurrence in dairy cows kept in organic and conventional production systemOcorrência de parasitas gastrintestinais em vacas leiteiras mantidas em sistema orgânico e convencional

    Directory of Open Access Journals (Sweden)

    Jenevaldo Barbosa da Silva

    2012-12-01

    Full Text Available The main aim of this study was to determine the effects of pregnancy, calving, lactation, lactation number and seasons on the population of gastrointestinal helminths in dairy cows kept in organic and conventional production system. Between January 2007 and December 2009, coproparasitologic exams were performed using 72 and 43cows kept in conventional and organic system, respectively. The data was submitted to analysis of variance and Student and Tukey test, both at 5% of significance level. There was no difference (p > 0.05 between faecal egg count (FEC of organic and conventional animals. The mean FEC during calving and lactation was higher (p O objetivo do estudo foi determinar os efeitos da gestação, parto, lactação, número de lactações e estação do ano sobre as populações de helmintos gastrintestinais em vacas leiteiras mantidas em sistema de manejo orgânico ou convencional. Entre janeiro de 2007 e dezembro de 2009 foram realizados exames coproparasitologicos de 72 vacas criadas em sistema convencional e 43 em sistema orgânico. Os dados foram submetidos a analise de variância e aos testes Student e Tukey a 5% de significância. Não foi observada diferença (p > 0,05 entre a contagem de ovos nas fezes (OPG dos animais orgânicos e convencionais. A média do OPG durante o parto e lactação foi maior (p <0 ,05 do que na gestação. Não foi observada influência da estação do ano sobre o OPG nos animais criados no sistema convencional, no entanto os animais do sistema orgânico foram mais parasitados (p <0 ,05 durante o período chuvoso. Em ambos os sistemas de produção os animais primíparos apresentaram OPG maior (p < 0,05 do que os animais pluríparos. Vacas de leite mantidas em sistema orgânico ou convencional foram igualmente vulneráveis a helmintoses subclínicas, sendo a ordem de parto um fator de risco nos dois sistemas.

  2. Analysis of economic break-even point of the biogas utilization for electrical power conversion: case study in a swine terminated unit; Analise do ponto de equilibrio economico da utilizacao do biogas para conversao em energia eletrica: estudo de caso em unidade de terminacao de suinos

    Energy Technology Data Exchange (ETDEWEB)

    Cervi, Ricardo Ghantous; Pinotti, Elvio Brasil [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Registro, SP (Brazil). Fac. de Ciencias Agrarias do Vale do Ribeira], e-mails: rghantous@registro.unesp.br, epinotti@registro.unesp.br; Esperancini, Maura Seiko Tsutsui; Bueno, Osmar de Carvalho [Universidade Estadual Paulista Julio de Mesquita Filho (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Gestao e Tecnologia Agroindustrial], e-mails: maura@fca.unesp.br, osmar@fca.unesp.br

    2010-07-01

    This work aimed to develop a study to estimate the break-even point in financial units of the electrical power generation using biogas from swine wastes. The analyzed biodigester is a continuous tubular model with brick concrete duct and plastic covering with a gasometer, and where the waste of 2,300 fattening pigs are deposited daily. The initial investment estimate for the installation was R$ 51,537.17. The system annual costs were R$ 5,708.20, for maintenance, R$ 4,390.40 for depreciation and R$ 1,366.77 for interests. It was noticed that with an average of consumption of 17.1 kW.hour{sup -1} the system presents an annual loss of R$ 1,592.14 because the consumption of 27.85 kW.hour{sup -1} is the minimum that should be consumed to achieve a corresponded financial break-even point of R$ 15,054.40.year{sup -1}. It was concluded that the correct technical dimensioning greatly influences on the economic results. (author)

  3. Cost analysis of electrical power from an ethanol reformer and the fuel cell in the development of productive activities in the community Pico do Amor, MT, Brazil; Analise do custo da energia eletrica proveniente de um reformador de etanol e celula a combustivel no desenvolvimento de atividades produtivas na comunidade Pico do Amor/MT

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Davi Gabriel; Teixeira, Andre Frazao; Lopes, Daniel Gabriel; Cavaliero, Carla Kazue Nakao [Universidade Estadual de Campinas (DE/FEM/UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Departamento de Energia; Instituto Aqua Genesis, Campinas, SP (Brazil); Hytron, Campinas, SP (Brazil)

    2010-07-01

    This work has the objective to analyze the impact of the cost of from an ethane reformer / fuel cell in the family income considering the development of two productive activities selected by the community itself: the production and marketing of cassava flour and 'rapadura', a typical brazilian candy. The community energy demand was analyzed to achieve the results; estimated the energy cost from the implemented system and the money from the selling of the cassava flour and 'rapadura' produced with this electricity; the study of sensibility of the ethanol price in the electrical energy cost was done too, and the cassava flour and 'rapadura' in the family funds. From the results, it was verified that the electrical energy cost has a 16,4% impact in the family gross income and a net value around R$ 260,85/family, indicating that the community will have enough funds to pay for the energy and also will rise the amount of money for each family. Besides, the comparative analyze of the cost of the electricity from the ethanol/fuel cell reformer and photovoltaic systems shows that, considering only the maintenance and operation costs, the first one should be more attractive than the second one. (author)

  4. Viability analysis of electric energy cogeneration in combined cycle with sugar-cane biomass gasification and natural gas; Analise de viabilidade da cogeracao de energia eletrica em ciclo combinado com gaseificacao de biomassa de cana-de-acucar e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Correa Neto, Vicente

    2001-03-15

    The objective of this thesis is evaluate the technical and economic viability of electric energy generation projects using as fuel the biomass produced in the sugar cane Brazilian industry, specifically the cane trash, the straw and the leaves of the plant, as complemental option to the expansion of the Brazilian electric system, hour in phase of deep modification in the institutional scenery, through the sale of electric energy for direct consumers or utilities, characterizing the business possibilities for the ethanol distilleries already integrated into the energy reality of the country. The analyzed technology is thermoelectric generation with combined cycle, operating in cogeneration, integrated to biomass gasification systems for the production of combustible gas, with and without addition of natural gas. The considered technology is known by the acronym BIG/GTCC, originated in Biomass Integrate Gasification Combined Cycle Gas Turbine. The economic analysis is made herself through a modeling and construction of economy project curves based on the prices of the electric energy, of the natural gas and in the costs of the retired biomass in an mechanized way.(author)

  5. Analysis of the pre-rift/rifte transition interval (Serraria and Barra de Itiuba formations) from the Sergipe-Alagoas basin; Analise da secao de transicao pre-rifte/rifte (formacoes Serraria e Barra de Itiuba) da Bacia Sergipe-Alagoas

    Energy Technology Data Exchange (ETDEWEB)

    Barreiro, C.B.; Mizusaki, A.M.P. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil)]. E-mail: camilita@terra.com.br; ana.misuzaki@ufrgs.br; Garcia, A.J.V. [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)]. E-mail: garcia@euler.unisinos.br

    2003-07-01

    The pre-rift/rift transition is represented by the Serraria and Barra de Itiuba formations. This interval was analyzed through qualitative and quantitative descriptions of cores, electric log analysis and studies of outcropping sections. The integration of surface and subsurface data allowed the stratigraphic characterization of sandstone bodies in the pre-rift/rift. These sandstones bodies were deposited by fluvial braided, lacustrine and deltaic systems (delta plain, delta front and pro delta). The sedimentary deposits characterized in the Serraria Formation are of channel, flooding of the fluvial system and eolic. The upper interval of this formation is characterized by to coarse medium-grained sandstones identified as the Caioba Sandstone. The Barra de Itiuba Formation contains lake, pro delta, frontal bar, distributary mouth, crevasse and distributary channel deposits. The sandstone units were specifically characterized in terms of their potential reservoir quality, and they were characterized the reservoirs R1 (good to medium quality) and Caioba (good quality) from the pre-rift phase, and reservoirs R2 (medium quality) and R3 (medium to good quality) from the rift phase. The reservoirs from pre-rift phase phase show the better reservoirs quality potential of the pre-rift/rift transition in the Sergipe-Alagoas Basin. (author)

  6. System Budgets

    DEFF Research Database (Denmark)

    Jeppesen, Palle

    1996-01-01

    The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers.......The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers....

  7. Variability in {sup 18}F-FDG PET/CT methodology of acquisition, reconstruction and analysis for oncologic imaging: state survey; Variabilidade metodologica na aquisicao, reconstrucao e analise de estudos de PET/CT oncologico com FDG-{sup 18}F: levantamento estadual

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Andreia C.F. da S.; Druzian, Aline C.; Pianta, Diego B.; Bacelar, Alexandre, E-mail: acfischer@hcpa.edu.br [Hospital de Clinicas de Porto Alegre, RS (Brazil); Silva, Ana M. Marques da [Pontificia Universidade Catolica do Rio Grande do Sul (NIMed/PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Fisica. Nucleo de Pesquisas em Imagens Medicas

    2016-07-01

    The SUV in {sup 18}F-FDG PET/CT oncological imaging is useful for cancer diagnosis, staging and treatment assessment. There are, however, several factors that can give rise to bias in SUV measurements. When using SUV as a diagnostic tool, one needs to minimize the variability in this measurement by standardization of patient preparation, acquisition and reconstruction parameters. The aim of this study is to evaluate the methodological variability in PET/CT acquisition in Rio Grande do Sul State. For that, in each department, a questionnaire was applied to survey technical information from PET/CT systems and about the acquisitions and analysis methods utilized. All departments implement quality assurance programs consistent with (inter)national recommendations. However, the acquisition and reconstruction methods of acquired PET data differ. The implementation of a harmonized strategy for quantifying the SUV is suggested, in order to obtain greater reproducibility and repeatability. (author)

  8. Thermal expansion analysis and structural characteristics of the (Pb, Ca)TiO{sub 3} solid solutions from 150 to 570 K; Analise da expansao termica volumetrica e das caracteristicas estruturais de solucoes solidas de (Pb, Ca)TiO{sub 3} entre 150 e 570 K

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, F.R.; Eiras, J.A.; Garcia, D., E-mail: frestrada@df.ufscar.br, E-mail: eiras@df.ufscar.br, E-mail: ducinei@df.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Fisica. Grupo de Materiais Ferroicos

    2017-01-15

    Ceramic samples of lead modified calcium titanate (Pb{sub 1-x}Ca{sub x} TiO{sub 3}) with calcium concentration between 0.24≤x≤0.55 were prepared and analyzed in order to determine the structural origin of the negative thermal expansion observed in this ferroelectric system. The Rietveld structural refinement method was used to assess the thermal evolution of the structural parameters using powder X-ray diffraction data collected between 150 and 570 K. Since the Pb{sub 1-x}Ca{sub x} TiO{sub 3} phase diagram and space groups are still unknown for the temperature range investigated, the structural analyses were based on adjustments of the refinement protocol. The results revealed the existence of a correlation between symmetry transitions and anomalies in the thermal expansion of the unit cell, being such transitions not necessarily of the ferroelectric-paraelectric nature. (author)

  9. Methodology for sizing, energy analysis and selection of equipment for a biomass gasifier to drive an internal combustion engine; Metodologia de dimensionamento, analise energetica e selecao de equipamentos de um gaseificador de biomassa para o acionamento de um motor de combustao interna

    Energy Technology Data Exchange (ETDEWEB)

    Coronado, Christian Rodriguez; Silveira, Jose Luz [Universidade Estadual Paulista (FEG/UNESP), Guaratingueta, SP (Brazil). Fac. de Engenharia], e-mails: christian@feg.unesp.br, joseluz@feg.unesp.br; Arauzo, Jesus Perez [University of Zaragoza (UNIZAR), Zaragoza (Spain). Centro Politecnico Superior. Chemical and Environmental Engineering Dept.], e-mail: qtarauzo@unizar.es

    2006-07-01

    Alter both oil crisis, of 1973 and 1979, a bad effect of the elevated costs and continuously increment of the oil prices was noted, for this reason, the interest for renewable energies sources widely available in developing countries was increased. All over the world, governments have formulated main objectives for energies savings and search for friendly technologies, taking into account the effects related with the environment. The imminent scarcity of fossil fuels has made humanity the rational use of primary energies, as a result of these; new plants with improved technology have been conceived taking into account energy savings and efficiency improvement. In this context, biomass gasification technologies are important, since they consist in techniques of parallel production of electricity and heat from just one fuel. This work consists in the development of a gasifier down draft of 100 kW for an internal combustion engine, which includes its sizing process and its energy analysis. The sizing includes design facts and the parameters of the conditioning systems for the exhaust gas. This part is mainly based in the experience of a work group of the Zaragoza State University - Spain, UNIZAR, specialists in the construction of small down draft gasifiers, for every case, air will be used as a gasifier agent and as biomass forestall. The availability of biomass resources and the application of the national energetic view system are relevant. The gasifier will have a 100 kg/h of feeding, the energetic analysis includes the matter and energy balance and the respective efficient such cold as hot efficient of the exhaust gas. Moreover it will be tried the equipment recommended for the cleaning and conditioning of this gas fuel for this equipment in particular. (author)

  10. Mudanças ambientais na região do cerrado. Analise das causas e efeitos da ocupação e uso do solo sobre o relevo. O caso da bacia hidrográfica do Rio Araguari-MG

    Directory of Open Access Journals (Sweden)

    Sílvio Carlos Rodrigues

    2002-12-01

    Full Text Available This paper presents our reflections over the main geomorphological characteristics of the Araguari River Basin and offers an analysis about the changes done by man over the landscapes. This region naturally occupied by savannas and in the last 40 years has been strongly altered by human activities. Summarized basic information is provided by geomorphological analysis especially done after geomorphological mapping correlated with geologic and soil maps and supported by field works. The report is divided into two main parts. The first part presents the natural arrangement of the landscapes that occurs into the hydrographic basin, showing the relationships between structural and geomorphic units. Information about superficial material, current processes and some evaluation about the evolution of these landforms are presented here. The second part presents the reflections due to antropic activities in the basin such as types of erosion, channels changes and urban problems. These activities are divided in which occurs in the farms and in the cities, showing the differences between actions over this sensitive system. In this part we showed the main research guidelines in course in this basin

  11. Management of the use of electric power in a university restaurant using fuzzy logic: analysis of the composition of this inputs in meal costs; Gerenciamento do uso da energia eletrica em um restaurante universitario utilizando a logica difusa: analise da composicao deste insumo nos custos da refeicao

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Humberto de Avila; Guimaraes Junior, Sebastiao Camargo; Camacho, Jose Roberto; Salerno, Carlos Henrique [Universidade Federal de Uberlandia (UFU), MG (Brazil). Fac. de Engenharia Eletrica. Nucleo de Eletricidade Rural e Fontes Alternativas de Energia; Bispo, Decio [Universidade Federal de Uberlandia (UFU), MG (Brazil). Fac. de Engenharia Eletrica. Nucleo de Maquinas Eletricas

    2004-07-01

    The objective of this work is to develop a computational tool to manage the use of electric energy of the university restaurant (Campus Santa Monica) at the Universidade Federal de Uberlandia (UFU) acting only in its working practices flowchart. This work has two phases. The first phase consists in the development of a computational program whose output data are related to electric energy use in a unit consumer, in this case the university restaurant (RU), such as: monthly maximum demand, monthly consumption, daily maximum demand, daily consumption, load factor, daily load curves, the value of the electric energy billing, the electric energy cost necessary to prepare a meal. The second phase, to be shown in a forthcoming paper, consists in the development of software using the Fuzzy Decision- Making System (FDMS). The FDMS will be used as an auxiliary tool to manage the use of electric energy in the RU and is intended to act only in its production process, that is, contemplating the menu's choice and the electric equipment' schedules. The FDMS can be considered as a tool that helps to manage the energy consumption. (author)

  12. Validation of methods for WDXRF and OES-spark techniques in steel analysis. Determination of the uncertainty of measurements for API steel plant sample; Validacao de metodos para as tecnicas de WDXRF e OES-spark na analise de acos. Calculo de incerteza de medicao para amostras de processo, aco classe API

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carlos Eduardo da

    2009-07-01

    The increase of gas and petroleum demanding in the national and international markets, the specification and certification of the chemical analysis results of gas and oil pipe-line have became more and more challenging. A continuous development has been outlined to improve API grade alloy steels (American Petroleum Institute). The steel properties depend on the chemical composition control and process parameters during its manufacturing. In this work, a comparison of the measurement uncertainty between X-ray fluorescence (WD system) and Optical Emission (OES-spark) spectrometry, for API grade steel plant samples analysis, was outlined. Usually, this kind of analyze requires less than 40 seconds for full chemical characterization for adjustment in the process parameters production. The main influence source in the chemical analysis was evaluated for design of experiments. The constituents and trace elements such as Al, Si, P, S, Ti, V, Cr, Mn, Co, Ni, Cu, As, Nb, Mo and Sn were determined using the ASTM E-322, E-415, E-1009 and E-1085 standard methodologies. The 185A and 187A certified reference materials from CMI (Czech Metrology Institute) were used for evaluation of the methods. The uncertainty of the measurement, precision, accuracy, repeatability and reproducibility of the measurements were obtained applying statistic tests, recommended by ISO/IEC 17025. The uncertainty of measurement for each element is discussed for both techniques. (author)

  13. Analysis of the distribution of government take arising from the oil and gas industry between the government spheres and its impact over the economy of Rio de Janeiro; Analise da reparticao das participacoes governamentais advindas da industria do petroleo entre as esferas de governo e seu impacto sobre a economia do Rio de Janeiro

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Juliana Barbosa; Szklo, Alexandre Salem

    2012-07-01

    Royalties and the windfall profits tax derived from petroleum exploration and production in Brazil are government take with huge impacts on the financial health of the state and cities of Rio de Janeiro. Considering the relevance of oil revenue, this study evaluates the significance of the amount transferred between government levels, comparing the current allocation system with international cases. The implemented methodology to reach the result has been the evaluation and data analysis, based on the finances of the state of Rio de Janeiro and the cities that have common borders with the Campos Basin. Furthermore, international cases have been analyzed. Findings indicate that, on one hand, the centralization of the oil revenue at federal level guarantees a better capacity to absorb uncertainties and the variation on the amount received; on the other hand, under a local level, it's possible to identify and better supply the local necessities and scarcities, not to mention, realize a more effective control. In the Brazilian case, this point is even more relevant, as far as debate concerning the distribution of government take cannot be done without considering a broader tax reform, especially in the case of petroleum, which should be associated with the incidence of ICMS on the destination.(author)

  14. Plan of development: analysis under the Brazilian petroleum act, the concession agreements and the ANP ordinance 90/2000; Plano de desenvolvimento: analise a luz da Lei do petroleo, dos contratos de concessao e da Portaria n. 90/2000 da ANP

    Energy Technology Data Exchange (ETDEWEB)

    Caroli, Carla [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    By the Plan of Development the concessionaire informs the petroleum regulatory agency (Agencia Nacional de Petroleo Gas e Biocombustiveis - ANP) how it intends to produce hydrocarbons from a field which was declared commercially feasible by such a concessionaire. Therefore, the Plan of Development consists of a very important document for ANP to conduct its supervision duties with regard to operations which usually take place during the development of the production. Because of its relevance within the E and P activities regulatory and supervision system in Brazil, the Plan of Development, its content and the requirements for its record before ANP are regulated by the Brazilian Petroleum Act (Lei n. 9.478/97) and also by the Concession Contracts and a government decree issue by the ANP itself (Portaria 90/2000), which approved a technical regulation on the Plan of Development. This essay will take all these rules into consideration in order to provide a summarized, systematic view of the discipline of the Plan of Development under Brazilian laws and regulations. In this sense, this essay intends to analyze not only the requirements for the preparation, presentation and possible changes in the Plan of Development, but also the legal principles applicable to the plan itself and to the conduct of the ANP before the projects presented by the concessionaires in accordance with such rules. (author)

  15. Analysis of the feasibility of applying the theory of the supply chain nanagement for the electric energy chain services of the Bahia state, Brazil; Analise da viabilidade de aplicacao da teoria da gestao da cadeia de suprimentos para a cadeia de servicos de energia eletrica do estado da Bahia

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Lydiane Abdon [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)], e-mail: lydianeleal@yahoo.com.br; Carvalho, Claudio Bezerra de [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil). Petroleo e Gas], e-mail: claudiobcarvalho@yahoo.com.br

    2008-07-01

    This article aims to analyze the potential application of integrated management, through concepts of SCM (Supply Chain Management), in the chain of the energy industry, which is characterized by a chain of services. The prospect of incorporating new integrated management practices, through the selection of concepts and tools for supply chain management took the possibility of promoting systemic approach that includes the major components (physical, regulatory and commercial) the market of electric energy, investigating possibilities of reorganization of this important segment of the industry production chain. The proposal aims to provide a tool for planning indicative of great potential, to identify a theoretical reference in this important productive sector. The work includes qualitative analyses, which aim to map, understand and systematize the changes undertaken, with emphasis on Brazilian electric sector. It is described, in general, the characterization of the energy industry in Bahia state as a possible case study in implementing the proposed methodology. Thus, the work seeks to help the staff decision to purchase a minimum of integrated vision of possible decisions, including the dynamic interactions between market supply and demand. (author)

  16. GESTÃO DA ÁGUA EM USINA DE CONCRETO: ANALISE DO RISCO DAS ATIVIDADES E MONITORAMENTO DA QUALIDADE DA ÁGUA RESIDUÁRIA PARA FINS DE REUSO (DOI.:10.5216/reec.V10i1.32759

    Directory of Open Access Journals (Sweden)

    Heber Martins de Paula

    2015-07-01

    Full Text Available RESUMO: As usinas de concreto vêm enfrentando o desafio de aumentar a produção, reduzindo o volume de resíduos gerados. Suas principais atividades demandam de volumes consideráveis de água que, ao mesmo tempo, não devem ser descartadas no solo ou redes coletoras, pois podem gerar riscos ao meio ambiente. Assim, este artigo tem como objetivo avaliar a frequência e o risco das atividades da usina quanto ao uso da água. Além disso, monitorar a qualidade da água do sistema de tratamento quanto ao pH e a turbidez. Para tanto, foi aplicado o método de Avaliação de Risco da Atividade aliado a observações realizadas in loco para melhor representar as ações de um dia convencional de produção. O levantamento foi realizado por seis dias aleatórios por três semanas consecutivas. Para avaliação da qualidade da água residuária foram monitorados o pH e a turbidez, sempre no último dia de produção da usina, representando a pior situação. Os resultados mostraram que a lavagem dos caminhões é a atividade que apresenta maior risco ao meio ambiente, pois acontece com maior frequência dentro do espaço de produção. O sistema atual não consegue remover a turbidez para destinação da água ao reuso, mantendo o pH acima de 12. ABSTRACT: The concrete plants are facing the challenge of increasing production, reducing the volume of waste generated. Its main activities require considerable volumes of water at the same time, should not be dismissed on the ground or collecting networks, they could generate risks to the environment. Thus, this article aims to evaluate the frequency and risk of the activities of the concrete plant on the use of water. In addition, monitor the quality of water treatment system for pH and turbidity. To this end, we applied the method of the Activity Risk Assessment together with in situ observations to better represent the actions of a conventional production day. The survey was conducted by six random days

  17. Analysis for impedance electrochemistry 'on-line' of membrane/electrode assemble (MEA) of protons exchange membrane fuel cells (PEMFC); Analise por impedancia eletroquimica 'on-line' de conjuntos eletrodos/membrana (MEA) de celulas a combustivel a membrana polimetrica (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonio Rodolfo dos

    2007-07-01

    This work reports results of studies and characterization on membrane electrode assemblies (MEAs) for proton exchange membrane fuel cell (PEMFC). Some cell operation conditions and different processes of MEA production were investigated. The electrochemical impedance spectroscopy technique (EIS) (in situ - 0 to 16 A) was used 'on-line' as a tool for diagnosis, concerning the cell performance. The EIS measurements were carried out with a FC350 Fuel Cell EIS System (GAMRY), coupled to a PC4 potentiostat/galvanostat and connected to the electronic load (TDI) for 'on-line' EIS experiments (100 mHz - 10 kHz, dU = 5 mV). MEAs with 25 cm{sup 2} surface area, using PtM/C 20% (M Ru, Sn or Ni) electrocatalysts were manufactured using the alcohol reduction process (ARP). The catalytic ink was applied directly into the carbon cloth (GDL) and pressed in the Nafion membrane (105). MEAs using Pt/C and Pt Ru/C 20% from E-TEK electrocatalysts were manufactured by comparison. All the cathodes were sprayed with Pt/C 20% from E-TEK. The noble metal concentrations used were set to 0.4 mg Pt.cm{sup -2} at the anode and 0.6 mg Pt.cm{sup -2} at the cathode (E-TEK). Nyquist diagrams of the MEAs with Pt/C and PtRu/C from E-TEK or PtM/C (M = Ru, Sn or Ni) ARP showed essentially the same ohmic resistances for the MEAs. This fact can be explained by suppression of agglomerates during the MEA preparation process or by the homogeneity of the anchored electrocatalysts at the carbon surface. It could also be observed, at low current densities, that there was a significant performance difference between the electrocatalysts from E-TEK and those prepared with the alcohol reduction process. The polarization curves results confirmed that the Pt M/C (M = Ru, Sn or Ni) ARP showed an activity increase for the methanol and ethanol fed cells. The technique of EIE was shown efficient for the evaluation of the method preparation of MEAs and the acting of the cell, the results of EIE

  18. Isolation of Pseudomonas aeruginosa strains from dental office environments and units in Barretos, state of São Paulo, Brazil, and analysis of their susceptibility to antimicrobial drugs Isolamento de cepas de Pseudomonas aeruginosa provenientes do meio ambiente e de equipos dentarios em clinicas dentarias em Barretos, São Paulo, Brasil; analises da susceptibilidade das cepas a drogas antimicrobianas

    Directory of Open Access Journals (Sweden)

    Ana Claudia de Oliveira

    2008-09-01

    Full Text Available A wide variety of opportunistic pathogens has been detected in the tubing supplying water to odontological equipment, in special in the biofilm lining of these tubes. Among these pathogens, Pseudomonas aeruginosa, one of the leading causes of nosocomial infections, is frequently found in water lines supplying dental units. In the present work, 160 samples of water, and 200 fomite samples from forty dental units were collected in the city of Barretos, State of São Paulo, Brazil and evaluated between January and July, 2005. Seventy-six P. aeruginosa strains, isolated from the dental environment (5 strains and water system (71 strains, were tested for susceptibility to six antimicrobial drugs most frequently used against P. aeruginosa infections. Susceptibility to ciprofloxacin, followed by meropenem was the predominant profile. The need for effective means of reducing the microbial burden within dental unit water lines is emphasized, and the risk of exposure and cross-infection in dental practice, in special when caused by opportunistic pathogens like P. aeruginosa, are highlighted.Uma ampla variedade de patógenos oportunistas tem sido detectadas nos tubos de alimentação de água dos equipos odontológicos, particularmente no biofilme formado na superfície do tubo. Entre os patógenos oportunistas encontrados nos tubos de água, Pseudomonas aeruginosa é reconhecida como uma das principais causadoras de infecções nosocomiais. Foram coletadas 160 amostras de água e 200 amostras de fomites em quarenta clinicas odontológicas na cidade de Barretos, São Paulo, Brasil, durante o período de Janeiro a Julho de 2005. Setenta e seis cepas de P. aeruginosa, isoladas a partir dos fomites (5 cepas e das amostras de água (71 cepas, foram analisadas quanto à susceptibilidade à seis drogas antimicrobianas freqüentemente utilizadas para o tratamento de infecções provocadas por P. aeruginosa. As principais suscetibilidades observadas foram para a

  19. Analysis for impedance electrochemistry 'on-line' of membrane/electrode assemble (MEA) of protons exchange membrane fuel cells (PEMFC); Analise por impedancia eletroquimica 'on-line' de conjuntos eletrodos/membrana (MEA) de celulas a combustivel a membrana polimetrica (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonio Rodolfo dos

    2007-07-01

    This work reports results of studies and characterization on membrane electrode assemblies (MEAs) for proton exchange membrane fuel cell (PEMFC). Some cell operation conditions and different processes of MEA production were investigated. The electrochemical impedance spectroscopy technique (EIS) (in situ - 0 to 16 A) was used 'on-line' as a tool for diagnosis, concerning the cell performance. The EIS measurements were carried out with a FC350 Fuel Cell EIS System (GAMRY), coupled to a PC4 potentiostat/galvanostat and connected to the electronic load (TDI) for 'on-line' EIS experiments (100 mHz - 10 kHz, dU = 5 mV). MEAs with 25 cm{sup 2} surface area, using PtM/C 20% (M Ru, Sn or Ni) electrocatalysts were manufactured using the alcohol reduction process (ARP). The catalytic ink was applied directly into the carbon cloth (GDL) and pressed in the Nafion membrane (105). MEAs using Pt/C and Pt Ru/C 20% from E-TEK electrocatalysts were manufactured by comparison. All the cathodes were sprayed with Pt/C 20% from E-TEK. The noble metal concentrations used were set to 0.4 mg Pt.cm{sup -2} at the anode and 0.6 mg Pt.cm{sup -2} at the cathode (E-TEK). Nyquist diagrams of the MEAs with Pt/C and PtRu/C from E-TEK or PtM/C (M = Ru, Sn or Ni) ARP showed essentially the same ohmic resistances for the MEAs. This fact can be explained by suppression of agglomerates during the MEA preparation process or by the homogeneity of the anchored electrocatalysts at the carbon surface. It could also be observed, at low current densities, that there was a significant performance difference between the electrocatalysts from E-TEK and those prepared with the alcohol reduction process. The polarization curves results confirmed that the Pt M/C (M = Ru, Sn or Ni) ARP showed an activity increase for the methanol and ethanol fed cells. The technique of EIE was shown efficient for the evaluation of the method preparation of MEAs and the acting of the cell, the results of EIE showed coherence in the

  20. Analysis of 83 consecutive liver transplants performed at a tertiary care reference hospital in the interior of the state of Sao Paulo Analise de 83 transplantes hepáticos consecutivos realizados em hospital universitário de referência terciária do interior do estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Ana Carolina Lombardi

    2011-12-01

    Full Text Available PURPOSE: To analyze pre-, intra- and immediate postoperative parameters of patients submitted to liver transplantation. METHODS: Eighty-three consecutive orthotopic liver transplants performed from January 2009 to July 2011 were analyzed. The patients were divided into 2 groups: A, survivors (MELD between 9 and 60 and B, non-survivors (MELD between 14 and 40, with 30.6% of group A patients being CHILD C, 51℅ CHILD B and 18,4℅ CHILD A. In group B ,32.1℅ of the patients were CHILD C, 42,9℅ CHILD B, and 25℅ CHILD A. All orthotopic liver transplantations were performed using the piggyback technique without a portacaval shunt. Systemic arterial pressure and serum ALT and AST levels were determined preoperatively and 5, 60 and 1440 minutes after arterial graft revascularization. Serum ALT and AST profiles were evaluated for seven days after surgery. RESULTS: Systemic arterial blood pressure levels, time of hot and hypothermic ischemia and time of graft implant were statistically similar for the two groups (p>0.05. Serum levels (U/L of ALT and AST at the 5, 60 and 1440 minute time points after arterial revascularization of the graft were also similar for the two groups studied, as also were the serum ALT and AST profiles. CONCLUSIONS: No statistically significant difference in any of the parameters studied was detected between the two groups. Under the conditions of the present study and on the basis of the parameters evaluated, no direct relation was detected between the intraoperative period and the type of patient outcome in the two groups studied.OBJETIVO: Analisar parâmetros do pré, intra e pós-operatório imediato de pacientes submetidos ao transplante de fígado. MÉTODOS: Foram analisados 83 transplantes ortotópicos de fígado realizados consecutivamente no período janeiro de 2009 a julho de 2011. Os pacientes foram dividos em dois grupos: A, survivors (MELD entre 16 e 60, e B, non-survivors (MELD entre 14 e 40 sendo que 30,6

  1. Visualization of the boiling phenomena and counter-current flow limit of annular heat pipe

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Kim, Kyung Mo; Jeong, Yeong Shin; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2015-10-15

    The thermal resistance of conventional heat pipes increases over the capillary limit because of the insufficient supplement of the working fluid. Due to the shortage of the liquid supplement, thermosyphon is widely used for vertically oriented heat transport and high heat load conditions. Thermosyphons are two-phase heat transfer devices that have the highly efficient heat transport from evaporation to condensation section that makes an upward driving force for vapor. In the condenser section, the vapor condenses and releases the latent heat. Due to the gravitation force acting on the liquid in the tube, working fluid back to the evaporator section, normally this process operate at the vertical and inclination position. The use of two-phase closed thermosyphon (TPCT) for the cooling devices has the limitation due to the phase change of the working fluid assisted by gravity force. Due to the complex phenomenon of two-phase flow, it is required to understand what happened in TPCT. The visualization of the thermosyphon and heat pipe is investigated for the decrease of thermal resistance and enhancement of operation limit. Weibel et al. investigated capillary-fed boiling of water with porous sintered powder wick structure using high speed camera. At the high heat flux condition, dry-out phenomenon and a thin liquid film are observed at the porous wick structure. Wong and Kao investigated the evaporation and boiling process of mesh wicked heat pipe using optical camera. At the high heat flux condition, the water filing became thin and partial dry-out was observed in the evaporator section. Our group suggested the concept of a hybrid heat pipe with control rod as Passive IN-core Cooling System (PINCs) for decay heat removal for advanced nuclear power plant. The hybrid heat pipe is the combination of the heat pipe and control rod. It is necessary for PINCs to contain a neutron absorber (B{sub 4}C) to have the ability of reactivity control. It has annular vapor space and

  2. Visualization of the boiling phenomena and counter-current flow limit of annular heat pipe

    International Nuclear Information System (INIS)

    Kim, In Guk; Kim, Kyung Mo; Jeong, Yeong Shin; Bang, In Cheol

    2015-01-01

    The thermal resistance of conventional heat pipes increases over the capillary limit because of the insufficient supplement of the working fluid. Due to the shortage of the liquid supplement, thermosyphon is widely used for vertically oriented heat transport and high heat load conditions. Thermosyphons are two-phase heat transfer devices that have the highly efficient heat transport from evaporation to condensation section that makes an upward driving force for vapor. In the condenser section, the vapor condenses and releases the latent heat. Due to the gravitation force acting on the liquid in the tube, working fluid back to the evaporator section, normally this process operate at the vertical and inclination position. The use of two-phase closed thermosyphon (TPCT) for the cooling devices has the limitation due to the phase change of the working fluid assisted by gravity force. Due to the complex phenomenon of two-phase flow, it is required to understand what happened in TPCT. The visualization of the thermosyphon and heat pipe is investigated for the decrease of thermal resistance and enhancement of operation limit. Weibel et al. investigated capillary-fed boiling of water with porous sintered powder wick structure using high speed camera. At the high heat flux condition, dry-out phenomenon and a thin liquid film are observed at the porous wick structure. Wong and Kao investigated the evaporation and boiling process of mesh wicked heat pipe using optical camera. At the high heat flux condition, the water filing became thin and partial dry-out was observed in the evaporator section. Our group suggested the concept of a hybrid heat pipe with control rod as Passive IN-core Cooling System (PINCs) for decay heat removal for advanced nuclear power plant. The hybrid heat pipe is the combination of the heat pipe and control rod. It is necessary for PINCs to contain a neutron absorber (B 4 C) to have the ability of reactivity control. It has annular vapor space and it

  3. Study of slag-refractory system in iron desulfurization process by isopleths from Ca O-Si O{sub 2}-Al{sub 2} O{sub 3} equilibrium diagram; Analise da interacao escoria de dessulfuracao de gusa - refratario do carro-torpedo a partir de projecao vertical no diagrama de equilibrio CaO-SiO{sub 2}-Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Marco Antonio; Tenorio, Jorge Alberto Soares [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    1996-12-31

    The sulfur withdrawal from liquid iron to compatible levels in steels plant processes capability is an important task of high quality rolled products fabrication. Mixture of lime forms a family of desulfurization agent frequently used, mainly their lower cost if injected in iron to reach not so lower levels of desulfurization. The use of this desulfurization agents produces approximately 7.0 Kg/t of slag, that results between 10 to 30 Kg/t of total slag. This slag interacts with the refractory lining of torpedo car, normally high alumina. In the present case it was analyzed an interaction between a slag formed by the use of the agent plus a blast furnace slag with a high alumina tar bonded lining. Isopleths of Ca O-Si O{sub 2}-Al{sub 2} O{sub 3} equilibrium diagram were constructed to represent the slag-refractory interaction. The results show that the use of the agent formed by lime and aluminium by-product is more deleterious to studied lining, what confirm the observations carried out in industrial plant. (author) 11 refs., 9 figs., 3 tabs.

  4. Ventilation systems

    International Nuclear Information System (INIS)

    Gossler

    1980-01-01

    The present paper deals with - controlled area ventilation systems - ventilation systems for switchgear-building and control-room - other ventilation systems for safety equipments - service systems for ventilation systems. (orig./RW)

  5. ’n Retoriese analise van Romeine 9:1–10:4

    Directory of Open Access Journals (Sweden)

    A.H. (Andries Snyman

    2015-06-01

    Full Text Available Die artikel is ’n poging om Paulus se retoriese strategie uit die teks self te rekonstrueer, eerder as om ’n klassieke of moderne retoriese model op die teks toe te pas. ’n Voorstel virso ’n teksgesentreerde benadering word kortliks opgesom, gevolg deur ’n beskrywing van die retoriese situasie wat Paulus in die brief wil ondersoek. Daar word geargumenteer dat Romeine 9:1–10:4 ’n integrale deel van Paulus se retoriese strategie vorm met die doel om sy gehoor te oortuig om sy siening van God se verlossingsplan, asook sy beoogde sending na Spanje te steun. In die proses van oorreding gebruik hy verskillende soorte argumente en retoriese tegnieke om die trefkrag van sy kommunikasie te verhoog. Die gevolgtrekkingis dat ’n teksgesentreerde benadering (met fokus op die funksionele aspekte van die teks ’n beter alternatief as die bestaande benaderings (met fokus op die formele aspekte van die teks bied. A rhetorical analysis of Romans 9:1-10:4. This article is an attempt to reconstruct Paul’s rhetorical strategy from the text itself, rather than applying ancient or modern rhetorical models to his letters. A proposal for such a text-centred approach is briefly summarised, followed by a discussion of the rhetorical situation that Paul wants to address in this letter. It is argued that Romans 9:1–10:4 forms an integral part of his rhetorical strategy, aimed at persuading his audience in Rome to support his view on God’s plan of salvationas well as his forthcoming mission to Spain. In the process of persuasion Paul uses various types of argument and rhetorical techniques to enhance the impact of his communication.The conclusion is that a text-centred approach (with its focus on the functional aspects of the text provides a better alternative to existing approaches (which focus on the formal aspects of the text.

  6. Nucleate boiling of halogenated coolants - correlation analysis; Ebulicao nucleada de refrigerantes halogenados: analise de correlacoes

    Energy Technology Data Exchange (ETDEWEB)

    Ribatski, Gherhardt; Jabardo, Jose M. Saiz [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Engenharia Mecanica

    1998-07-01

    Present study has been focused on a literature of heat transfer under nucleate boiling conditions of halocarbon refrigerants and their mixtures with lubricating oil. Two kind of correlations regarding the heat transfer mechanism have been found: strictly empirical, based on a straight curve fitting of experimental data, and semi-empirical, based on the particular point of view of the author regarding the physical mechanism but still fitted with experimental data. As a general rule, it has been noted that correlations present significant discrepancies among each other, a result which mostly reflects the wide range of experimental conditions used as a reference. A similar trend has been observed with refrigerant/oil mixtures. Given the current status of halocarbon refrigerants for refrigeration applications, there is clearly a need for further research regarding the nucleate boiling phenomenon related to those compounds. (author)

  7. Analysis of the computed tomography in the acute abdomen; Analise da tomografia computadorizada no abdome agudo

    Energy Technology Data Exchange (ETDEWEB)

    Hochhegger, Bruno [Complexo Hospitalar Santa Casa de Porto Alegre, RS (Brazil); Moraes, Everton [Universidade Federal de Santa Maria (UFSM), RS (Brazil); Haygert, Carlos Jesus Pereira; Antunes, Paulo Sergio Pase [Hospital Universitario de Santa Maria, RS (Brazil); Gazzoni, Fernando [Pontificia Universidade Catolica de Porto Alegre (PUC-RS), Porto Alegre, RS (Brazil). Hospital Sao Lucas; Andrade, Rubens Gabriel Feijo [Fundacao Universitaria de Cardiologia de Porto Alegre, RS (Brazil). Inst. de Cardiologia; Bueno, Leticia Rossi [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Lopes, Luis Felipe Dias [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Estatistica]. E-mail: brunorgs@pop.com.br

    2007-07-01

    Introduction: This study tends to test the capacity of the computed tomography in assist in the diagnosis and the approach of the acute abdomen. Material and method: This is a longitudinal and prospective study, in which were analyzed the patients with the diagnosis of acute abdomen. There were obtained 105 cases of acute abdomen and after the application of the exclusions criteria were included 28 patients in the study. Results: Computed tomography changed the diagnostic hypothesis of the physicians in 50% of the cases (p < 0.05), and the confidence index in 85.71% of the cases (p 0.014). Computed tomography also altered the management in 46.43% of the cases (p > 0.05), where 78.57% of the patients had surgical indication before computed tomography and 67.86% after computed tomography (p = 0.0546). The index of accurate diagnosis of computed tomography, when compared to the anatomopathologic examination and the final diagnosis, was observed in 82.14% of the cases (p = 0.013). When the analysis was done dividing the patients in surgical and nonsurgical group, were obtained an accuracy of 89.28% (p 0.0001). The difference of 7.2 days of hospitalization (p = 0.003) was obtained compared with the mean of the acute abdomen without use the computed tomography. Conclusion: The computed tomography is correlative with the anatomopathology and has great accuracy in the surgical indication, associated with the capacity of increase the confident index of the physicians, reduces the hospitalization time, reduces the number of surgeries and is cost-effective. (author)

  8. Analise da influencia das fontes de carbono na patogenicidade do Moniliophthora perniciosa pathogenicity em Theobroma cacao

    OpenAIRE

    Fatima Cerqueira Alvim

    2009-01-01

    Resumo: O fungo basidiomiceto hemibiotrófico Moniliophthora perniciosa, agente causal da doença vassoura-de-bruxa (VB) em Theobroma cacao, é o principal patógeno da lavoura cacaueira nas Américas e no Caribe. O presente trabalho apresentou como objetivo primordial identificar proteínas relacionadas com a patogenicidade deste fungo. No primeiro capítulo desta tese foi demonstrado o efeito de diferentes fontes de carbono sobre a morfologia e fisiologia do M, perniciosa. O fungo foi crescido em ...

  9. Analise dos efeitos de diferentes parametros na estabilidade de vitamina C em vegetais processados

    OpenAIRE

    Marta de Toledo Benassi

    1990-01-01

    Resumo: O trabalho foi conduzido no sentido de se estudar a estabilidade e verificar a cinética de perda de vitamina C em diferentes processos, utilizando-se como, matéria prima, vegetais selecionados: couve, couve-flor e pimentão. Foram feitos diferentes tipos de cozimento (água, vapor e microondas) e estocagem (temperatura ambiente, refrigerada e congelada), variando-se os tempos e condições de processamento. Foi constatado que as perdas de vitamina C nos produtos, durante o cozimento em ág...

  10. Vermiculites of the Northeast Brazilian region: comparative analysis; Vermiculitas da regiao do nordeste brasileiro: analise comparativa

    Energy Technology Data Exchange (ETDEWEB)

    Silva, P S; Hanken, R B.L. [Universidade Federal de Campina Grande (UAEMa/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Raposo, C M.O., [Universidade Federal de Campina Grande (UAMG/UFCG), PB (Brazil). Unidade Academica de Mineracao e Geologia

    2009-07-01

    Vermiculites are clay minerals similar to montmorillonites differing for crystalline structures. The product exfoliated is odorless, hydrophobic, not irritate the skin and not the lungs. These properties provide the modified thermally vermiculite a product of broad application in the sectors of construction, agriculture and industry. The aim this work is the comparative analysis between two vermiculites micron fractions from different localities of the northeastern Brazilian region, UBM/PB and EUCATEX/PI. Samples exfoliated to 950 deg C were leached for removal of organic matter by oxidation with hydrogen peroxide. The spectroscopy in the infrared, FTIR and X-ray diffraction, XRD, were used to characterize the samples. Data from X-ray diffraction showed that the structural characteristics of the mineral samples were not significantly altered with the process of leaching and the IR spectra proved the efficiency of procedure for removal of organic impurities (author)

  11. MARA - methodology to analyze environmental risks; MARA - elaboracao de metodologia para analise dos riscos ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Renato F; Yogui, Regiane [PETROBRAS, Rio de Janeiro, RJ (Brazil); Minniti, Vivienne [Companhia de Tecnologia de Saneamento Ambiental (CETESB), Sao Paulo, SP (Brazil). Setor de Analise de Riscos; Lopes, Carlos F [Companhia de Tecnologia de Saneamento Ambiental (CETESB), Sao Paulo, SP (Brazil). Setor de Operacoes de Emergencia; Milaneli, Joao [Companhia de Tecnologia de Saneamento Ambiental (CETESB), Ubatuba, SP (Brazil). Agencia Ambiental de Ubatuba; Torres, Carlos [TRANSPETRO - PETROBRAS Transportes, Sao Paulo, SP (Brazil). Seguranca, Meio Ambiente e Saude; Rodrigues, Gabriela; Mariz, Eduardo [Consultoria Paulista, SP (Brazil)

    2005-07-01

    In the oil industry, the environmental impact assessment of an accident is both multi and interdisciplinary and goes through several approaches and depths. Due to the enormous complexity of the environmental analyses issues, mainly for being a science in development and not technological consensus, a macro methodology is presented for the purpose of identify areas that can be impacted by pipeline leakages and recommend improvements are applicable working as a table top response plan. The methodology of the Environmental Risk Mapping-MARA for pipelines rows, describes its concept and justifies the adoption of the environmental mapping during Risk Analyses studies, for PETROBRAS/TRANSPETRO new and existing pipelines. The development of this methodology is justified by the fact that it is a practical tool for identification, analysis and categorization of the more vulnerable environmental elements along a pipeline row and vicinities, during simulated occurrence of accidental spills of hydrocarbons in the environment. This methodology is a tool that allows Environmental Agencies and PETROBRAS a better way to manage in advance the Company emergencies. (author)

  12. Corrosion analysis in mooring chain links; Analise de corrosao em elos de amarras

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Silvia N.; Pereira, Marcos V. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Ciencia dos Materiais e Metalurgia; Costa, Luis C. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Motta, Sergio H. [Brasilamarras - Companhia Brasileira de Amarras, Niteroi, RJ (Brazil)

    2004-07-01

    The purpose of this work was to characterize the localized corrosion phenomenon in the weld region of offshore mooring chain links type ORQ. In this sense, a number of chain links were selected after finishing their projected life time without corrosion signs (chains without corrosion) as well as chain links which showed a reduced life time caused by localized corrosion (chains with corrosion). In the sequence, electrochemistry tests evaluated the corrosion susceptibility of the different regions of the weld joint. The results showed that the heat affected zone concerning the chains with corrosion was the anodic region, with high corrosion rate, while the same region on the not corroded chains was the cathodic one, with low corrosion rate. (author)

  13. Habilidade motora fundamental : analise comparativa entre situação laboratorial e "natural"

    OpenAIRE

    Helder Ferreira Isayama

    1997-01-01

    Resumo: O objetivo deste estudo foi verificar se existe variação na execução dos padrões de movimento arremessar e receber em duas situações ambientais diferentes: situação laboratorial (onde ocorreu um maior controle das variáveis) e situação "natural" (próxima da situação que ocorre em aula de Educação Física). Os participantes deste estudo foram 28 crianças de ambos os sexos e com 4 anos de idade. As crianças em movimento foram filmadas realizando as duas habilidades motoras fundamentais -...

  14. Padrão fundamental de movimento : uma analise universal ou contextual?

    OpenAIRE

    Inara Marques

    1995-01-01

    Resumo: Este trabalho teve como objetivo verificar se houve modificação ou alteração nos níveis de desenvolvimento em relação ao objetivo da tarefa. Para este fim, os padrões fundamentais de movimento arremessar e chutar foram executados em duas situações diferentes: ao alvo e à distância e analisados em 50 crianças de 7 anos de idade. Estas crianças foram selecionadas na Escola Municipal de 10grau "Violeta Dória Lins", localizada no bairro Vila Rica, no município de Campinas (SP) e as tarefa...

  15. Traumatismos maxilofaciais como marcadores de violencia urbana: uma analise comparativa entre generos

    Directory of Open Access Journals (Sweden)

    Carlos Jose de Paula Silva

    2014-01-01

    Full Text Available A violência tem sido um tema amplamente discutido em diversos setores da sociedade, quer pelo reflexo nos indicadores de segurança pública, pela influência no cotidiano dos indivíduos ou pela presença constante de vítimas nos serviços de saúde. O estudo avaliou comparativamente as diferenças de vitimização entre os gêneros a partir dos traumatismos maxilofaciais como marcadores de violência urbana. Trata-se de um estudo transversal com dados coletados em três hospitais especializados no atendimento a politraumatismos em Belo Horizonte (MG, entre janeiro de 2008 e dezembro de 2010. As análises envolveram estatística descritiva e multivariada por regressão logística. Identificou-se o registro de 7.063 vítimas, sendo 55,1% de violência interpessoal. A maioria das vítimas era do sexo masculino (71,2%. Nos homens, as agressões por arma de fogo, arma branca e acidentes motocilísticos foram as mais importantes quando comparadas às agressões nuas ou sem uso de armas. As fraturas múltiplas foram o tipo de traumatismo que melhor caracterizou o perfil de vitimização para o sexo masculino comparativamente às lesões de partes moles. O gênero é um importante fator na vitimização por traumatismo maxilofacial e violência urbana, sendo que os homens são as principais vítimas.

  16. Analise do pre-processamento da erva-mate para chimarrão

    OpenAIRE

    Agenor Maccari Junior

    2005-01-01

    Resumo: o cultivo e o processamento da erva-mate (1. paraguariensis) têm importante papel na economia dos Estados do Sul do Brasil, uma vez que tais atividades estão presentes em pequenas propriedades e indústrias, gerando milhares de empregos. Entretanto, o setor enfrenta dificuldades, sendo que as indústrias devem reduzir custos e gastos com energia, mantendo qualidade na produção. Uma alternativa é a adequação da tecnologia utilizada no processamento da erva-mate. Para tanto, este trabalho...

  17. Antivirais incorporados no Brasil para hepatite B cronica: analise de custo-efetividade

    Directory of Open Access Journals (Sweden)

    Gustavo Laine Araujo de Oliveira

    2013-08-01

    Full Text Available OBJETIVO Avaliar o custo-efetividade de diferentes tratamentos medicamentosos para hepatite B crônica entre pacientes adultos. MÉTODOS Utilizando modelo de Markov, construiu-se coorte hipotética de 40 anos para pacientes HBeAg-positivo ou HBeAg-negativo. Foram comparados os usos de adefovir, entecavir, tenofovir e lamivudina (com terapia de resgate em caso de resistência viral para tratamento de pacientes adultos com hepatite B crônica, virgens de tratamento, com elevados níveis de alanina aminotransferase, sem evidência de cirrose e sem coinfecção por HIV. Valores para custo e efeito foram obtidos da literatura. A medida do efeito foi expressa em anos de vida ganhos (AVG. Taxa de desconto de 5% foi aplicada. Análise de sensibilidade univariada foi conduzida para avaliar incertezas do modelo. RESULTADOS O tratamento inicial com entecavir ou tenofovir apresentou melhores resultados clínicos. As menores razões custo-efetividade foram de entecavir para pacientes HBeAg-positivo (R$ 4.010,84/AVG e lamivudina para pacientes HBeAg-negativo (R$ 6.205,08/AVG. Para pacientes HBeAg-negativo, a razão custo-efetividade incremental de entecavir (R$ 14.101,05/AVG está abaixo do limiar recomendado pela Organização Mundial da Saúde. Análise de sensibilidade mostrou que variação nos custos dos medicamentos pode tornar tenofovir alternativa custo-efetiva tanto para pacientes HBeAg-positivo quanto para HBeAg-negativo. CONCLUSÕES Entecavir é alternativa recomendada para iniciar o tratamento de pacientes com hepatite B crônica no Brasil. Contudo, se houver redução no custo de tenofovir, esta pode se tornar alternativa mais custo-efetiva.

  18. Conformational analysis of lignin models; Analise conformacional de modelos de lignina

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Helio F. dos [Juiz de Fora Univ., MG (Brazil). Dept. de Quimica]. E-mail: helius@quimica.ufjf.br

    2001-08-01

    The conformational equilibrium for two 5,5' biphenyl lignin models have been analyzed using a quantum mechanical semiempirical method. The gas phase and solution structures are discussed based on the NMR and X-ray experimental data. The results obtained showed that the observed conformations are solvent-dependent, being the geometries and the thermodynamic properties correlated with the experimental information. This study shows how a systematic theoretical conformational analysis can help to understand chemical processes at a molecular level. (author)

  19. Thermal hydrodynamic analysis of a countercurrent gas centrifuge; Analise termo hidrodinamica de uma centrifuga a contracorrente

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei Alves de

    1999-07-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  20. Extração de acido carminico e analise por cromatografia liquida de alta eficiencia

    OpenAIRE

    Paulo Roberto Nogueira Carvalho

    1996-01-01

    Resumo: A preocupação dos consumidores com o uso de substâncias artificiais em alimentos tem aumentado muito nos últimos anos e feito com que os fabricantes procurem substitutos para os corantes artificiais ainda utilizados. O carmim de cochonilha, nome dado ao complexo de alumínio e cálcio do ácido carmínico (ácido 7- b - D - glicopiranosil - 9, 10 - diidro - 3, 5, 6, 8 - tetraidroxil - 1 - metil - 9, 10 - dioxo - 2 - antracenocarboxílico), extraído das fêmeas da cochonilha (Dactylopius cocc...

  1. Business analysis of generation considering environmental opportunities; Analise de negocios de geracao considerando oportunidades ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Cyrillo, Ivo Ordonha [Universidade de Sao Paulo (ENERQ/USP), SP (Brazil). Centro de Estudos em Regulacao e Qualidade de Energia; Pelegrini, Marcelo A.; Gemignani, Matheus M.F.

    2008-07-01

    The project 'Business's Power Generation Evaluation Considering Environmental Opportunities' is about developing a methodology to analyze feasibility of new power generation factory from the point of view of the investor, examining the technical, economic-financial, risk, regulatory, social and environmental aspects. The opportunities arising from Kyoto Protocol were added in feasibility's analysis. (author)

  2. Desigualdades sociais e tuberculose: analise segundo raca/cor, Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Paulo Cesar Basta

    2013-10-01

    Full Text Available OBJETIVO Analisar características sociodemográficas e clínico-epidemiológicas dos casos de tuberculose e fatores associados ao abandono e ao óbito na vigência do tratamento. MÉTODOS Estudo epidemiológico baseado em dados notificados de tuberculose em indígenas e não indígenas, segundo raça/cor, em Mato Grosso do Sul, entre 2001 e 2009. Realizou-se análise descritiva dos casos de acordo com as variáveis sexo, faixa etária, zona de residência, exames empregados para o diagnóstico, forma clínica, tratamento supervisionado e situação de encerramento, segundo raça/cor. Utilizou-se análise univariada e múltipla por meio de regressão logística para identificar preditores de abandono e óbito, e odds ratio como medida de associação. Foi construída série histórica de incidência, segundo raça/cor. RESULTADOS Registraram-se 6.962 casos novos de tuberculose no período, 15,6% entre indígenas. Houve predomínio em homens e adultos (20 a 44 anos em todos os grupos. A maior parte dos doentes indígenas residia na zona rural (79,8% e 13,5% dos registros nos indígenas ocorreram em 45 anos (OR = 3,0; IC95% 1,2;7,8 e com a forma mista (OR = 2,3; IC95% 1,1;5,0 apresentaram associação com óbito. Apesar de representarem 3,0% da população, os indígenas foram responsáveis por 15,6% das notificações no período. CONCLUSÕES Houve importantes desigualdades em relação ao adoecimento por tuberculose entre as categorias estudadas. As incidências nos indígenas foram consistentemente maiores, chegando a exceder em mais de seis vezes as médias nacionais. Entre pretos e pardos, piores resultados no tratamento foram observados, pois apresentaram chance de abandono duas vezes maior que os indígenas. O mau desempenho do programa também esteve fortemente associado ao abandono e ao óbito. Acredita-se que, enquanto não se reduzir a pobreza, as desigualdades nos indicadores em saúde permanecerão.

  3. A severidade de corte no sisal e analise tecnológica da fibra

    Directory of Open Access Journals (Sweden)

    J. C. Medina

    1947-01-01

    Full Text Available In this paper it is presented a detailed fiber analysis of leaves of twenty mature sisal plants taken from four positions on the plant: 1 first developped leaves (75°; 2 leaves usually cut for fiber extraction (50° ; 3 leaves adjacent to the central bud (25° ; and 4 young leaves not yet unfolded from the central bud (0°. The results herein reported are against the prevailing opinion that the sisal leaf only matures after it has unfolded from the central bud. Neither the physical nor the chemical fiber characteristics were adversely affected even if cutting was carried out up to the very young leaves. This practice, however, cannot yet be advised, as it desirability also depends on the effects of the severe cutting upon the subsequent rate of growth of the new leaves. A cutting trial including the cut of all leaves every four months is still in progress. Preliminary results have shown that the plants of this treatment were able to develop eight leaves until the second cut, with an average fiber content of 3,7%.

  4. Thermal hydrodynamic analysis of a countercurrent gas centrifuge; Analise termo hidrodinamica de uma centrifuga a contracorrente

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei Alves de

    1999-07-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  5. ’n Retoriese analise van die vyf lykdigte in T.T. Cloete se Allotroop

    Directory of Open Access Journals (Sweden)

    L. Viljoen

    1995-05-01

    This article works from the premise that these poems form part o f a tradition that can he traced back to the funerary poetry of the Dutch Renaissance and from there to the funeral orations of Classical times. After referring to the current revival of interest in rhetoric, attention is given to the role which rhetoric played in Renaissance poetics and the influence it had on the practice of writing funerary poetry. The funerary poems in Cloete's Allotroop are then analysed, making use of the Renaissance descriptions of and prescriptions for funerary poetry researched by S.F. Witstein in Funeraire poëzie in de Nederlandse Renaissance. These analyses prove that Cloete’s poems make use of the elements basic to the Renaissance funerary poem and the classical funeral oration namely praise (laus, mourning (luctus and consolation (consolatio and that the rhetorical terminology devised centuries ago can still be useful in the reading of these poems.

  6. Exergetic analysis in petroleum primary separation plants; Analise exergetica em plantas de separacao primaria de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ghiorzi, Telmo Machado

    1997-07-01

    This dissertation presents a method for evaluate the efficiency of primary petroleum separation plants off-shore, using the concept of exergy. This concept is presented as a thermodynamic property and one shows how to calculate its value. A bibliographic revision is done, as well as, the necessary adaptations and considerations foe exergy application on off-shore plants: It is presented a way to evaluate efficiency on plants which part of the products is used as the drive-force of the process and it is presented the exergy calculation for mixtures, through departure functions. This calculation deserves special attention due to Equilibrium-Liquid-Vapour behavior of the mixtures when brought to ambient conditions. Some hypothetical cases, carried out using the Process Simulator HYSIM, are analyzed. The conclusions and recommendations are related to design and operation of off-shore plants and perspectives to follow on the subject exergy and the petroleum industry. (author)

  7. Liquids contamination analysis using ultrasonic technology; Analise de contaminacao de liquidos utilizando tecnologia ultra-sonica

    Energy Technology Data Exchange (ETDEWEB)

    Sbalqueiro Neto, Orlando; Neves Junior, Flavio [Centro Federal de Educacao Tecnologica do Parana (CEFET-PR), Curitiba, PR (Brazil)

    2004-07-01

    The easiness of the ultrasonic technology in the liquids quality control on-line, without intrusiveness, installation easiness and manuscript easiness (for the fact of not being toxic as X-rays) are the reasons to become this one of the best chooses. This work presents the development position period of an equipment and a methodology for a problem solution of filters disruption. For such, a revision of the techniques used currently was made and after one brief theoretical revision presents a practical methodology and its results for a refinery oils. In this in case that the industry using presses filters to eliminate particles, residues of the process. The disruption of these filters can cause the loss of part of the production. An equipment that determined if occurred or not an imperfection in the filter would prevent much damage. The results present that the methodology today used solve this problem, but for a higher precision of determination product quality exists the necessity to develop new works with new methodologies. (author)

  8. Asphaltenes analysis arising of non conventional oils; Analise de asfaltenos oriundos de petroleos nao convencionais

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fernanda B. da; Fiorio, Paula G.P.; Guimaraes, Maria Jose O.C.; Seidl, Peter R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2012-07-01

    The need to use heavy fractions in an efficient way in the production of nobler fractions has motivated the search for ways of separating the asphaltenes, since these molecules increase the viscosity of the fractions submitted to distillation, contribute to the formation of coke and to poisoning and deactivation of catalysts used in process such as cracking, reform, etc, besides provoking cloggings and blockages caused by its deposition, generating losses on the productivity and increases of the operational costs. This paper evaluates the influence of solvent blends (EQ-NP) in the selective extraction of constituents of three samples from Brazilian heavy crude. For the extraction process was used two solvent blends (N1P1 and N1P2). The solvent blend composed of N1P1 showed a higher selectivity in the extraction of aggregates than N1P2. The extracted fraction was characterized by Hydrogen Nuclear Magnetic Resonance ({sup 1}H-NMR) and revealed that the chemical species extracted from different blends exhibit very small differences. (author)

  9. 'n Media-analise oor misdaad in die Suid-Afrikaanse onderwys

    African Journals Online (AJOL)

    Erna Kinsey

    A culture of violence and crime reigns in education. A spirit of despair and .... Despite the government's ban on corporal punishment ... pupils continue to be ... Rights of Children en die Universal declaration of Human Rights is tekenend van 'n ...

  10. Winston-Lutz Test: A quantitative analysis; Teste de Winston-Lutz: uma analise quantitativa

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Aline Garcia; Nandi, Dorival Menegaz; Saraiva, Crystian Wilian Chagas, E-mail: dnandi@gmail.com [Universidade Federal de Santa Catarina (UFSC), Florianopolis (Brazil); Instituto Federal de Santa Catarina (IFSC), Florianopolis (Brazil); Hospital do Coracao, Sao Paulo, SP (Brazil)

    2017-11-01

    Objective: Describe a method of quantitative analysis for the Winston-Lutz test. Materials and methods The research is a qualitative exploratory study. The materials used were: portal film; Winston- Lutz test tools and Omni Pro software. Sixteen portal films were used as samples and were analyzed by five different technicians to measure the deviation between the radiation isocenters and mechanic. Results: Among the results were identified two combinations with offset values greater than 1 mm. In addition, when compared the method developed with the previously studied, it was observed that the data obtained are very close, with the maximum percentage deviation of 32.5%, which demonstrates its efficacy in reducing dependence on the performer. Conclusion: The results show that the method is reproducible and practical, which constitutes one of the fundamental factors for its implementation. (author)

  11. ’n Analise van geselekteerde mediaberigte se uitbeelding van rassisme in Suid- Afrikaanse skole

    Directory of Open Access Journals (Sweden)

    C. de Wet

    2001-08-01

    Full Text Available An analysis of the portrayal of racism in South African schools in selected media reports The influence of the printed media on the establishment of perceptions and as a source of information must not be underestimated. Although it is generally accepted that no editor will publish a report containing false information, there are many journalistic tricks of the trade that can be used in support of a specific political and/or economic view. In this article an attempt was made to find out how and with what purpose in mind the printed media, accused of perpetuating racism in the South African society, report on racial conflict and tension in education, a social relationship that also seems to be interlarded with racism.

  12. Balanço comercial numa analise quantitativa Trade balance in quantitative analysis

    Directory of Open Access Journals (Sweden)

    Martus Antonio Rodrigues Tavares

    1981-11-01

    Full Text Available Tentativa de comprovação da validade do modelo econométrico utilizado por Lemgruber no período 1965-1974. Procedeu-se ao teste do modelo, utilizando-se o período de 1965-1977 a fim de realizar a comprovação pretendida, face a nova conjuntura internacional de elevados preços do petróleo, de desvalorização do dólar frente às moedas de alguns países industrializados e de baixo crescimento da economia mundial, bem como das mudanças na política econômica de comércio exterior do Brasil. Procedeu-se também a um teste de modelo alternativo para melhor aplicação econométrica a conjuntura atual de comércio exterior. Ao final observou-se que os modelos estudados são suficientes para mostrar que a melhora do nosso balanço comercial está sujeita às variáveis externas como, renda mundial, preços de importações e exportações, não se desprezando também a variável interna — taxa de câmbio.Attempt to confirm the validity of the econometric model utilized by Lemgruber for the period 1965-1974. This model was applied to the period 1965-1977, in order to test it in the face of a new set of international crisis, such as the increase of petroleum prices, the devaluation of the dollar in relation to the currencies of other industrial countries, and the low growth-rate of the world economy, as well as in the face of the changes in Brazil's foreign economic policy. An alternative model was also tested for econometric applicability to the actual situation of foreign trade. It was observed, in the end, that the models studied sufficiently demonstrated that the improvement of our balance of trade is subject to such external variables as world income and import-export prices, as well as to the internal variable of exchange rate.

  13. Analysis of medical exposures in digital mammography; Analise das exposicoes medicas em mamografia digital

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Sergio R., E-mail: oliveirasr@fiocruz.br [Escola Politecnica de Saude Joaquim Venancio (EPSJV/FIOCRUZ), Rio de Janeiro, RJ (Brazil); Mantuano, Natalia O.; Albrecht, Afonso S., E-mail: nataliamantuano@gmail.com, E-mail: afonsofismed@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Fisica; Flor, Leonardo S., E-mail: leonardo.flor@hsvp.org.br [Hospital Sao Vicente de Paulo (HSVP), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Currently, the use of digital mammography in the early diagnosis of breast cancer is increasingly common due to the production of high definition image that allows to detect subtle changes in breast images profiles. However it is necessary to be an improvement of the technique used since some devices offer minimization parameters of entrance dose to the skin. Thus, this study seeks to examine how the qualification of technical professionals in radiology interferes with the use of the techniques applied in mammography. For this, survey was carried out in a hospital in the city of Rio de Janeiro, which evaluated the scans of 1190 patients undergoing routine mammography (It is considered routinely the 4 basic exhibitions: with 2 flow skull and 2 medium oblique side, excluding repeats and supplements) in 2013. The medical exposures analyzed obtained from a single full digital equipment, model Senographe DS were compared with three different procedures performed by professionals in mammography techniques. The images were classified according to exposure techniques available in the equipment: Standard (STD), contrast (CNT) and dose (dose), and to be selected as breast density of the patient. Comparing the variation of the radiographic technique in relation to the professional who made the exhibition, what is observed is that the professional B presented the best conduct in relation to radiological protection, because she considered breast density in the choice of technical equipment parameter. The professional A, which is newly formed, and C, which has more service time, almost did not perform variations in the pattern of exposure, even for different breast densities. Thus, we can conclude that there is a need to update the professionals so that the tools available of dose limitation and mamas variability to digital mammography are efficiently employed in the service routine and thus meet the requirements of current legislation.

  14. Sustainability analysis in petroleum production facilities; Analise de sustentabilidade em instalacoes de producao de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Jose Marcos Leite [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Santos, Adriano [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil); Fernandes Junior, Wilaci Eutropio [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2012-07-01

    The global sustainability aspects are discussed and a method for sustainability analysis in oil and gas production surface facilities is presented. The proposed method requires a multidisciplinary viewpoint and considers social, economic and environmental sustainability aspects during the early design programming and planning phases. Traditionally, Feasibility (Technical and Economical), Environmental Impact Assessment (EIA) and risk (Hazop) analysis are performed separately. On the other hand, the proposed methodology merges economical, environmental and social sustainability analysis; which allows deciding the most globally sustainable scenario. A checklist containing global sustainability aspects (Economical, Social, Environmental, Health, Safety, etc.) and a qualitative analysis of these aspects is suggested. The first step for applying the proposed method consists in checking the aspects and the corresponding suggestions for improving the global sustainability. Secondly, the impact of each aspect on sustainability is verified. Finally, the most important aspects are selected and different scenarios are simulated allowing choosing the most sustainable scenario. The results and conclusions are then presented in a Global Sustainability Report. The proposed analysis was applied to study the sustainability of a small offshore platform design. In this case study, several aspects that could potentially improve sustainability were identified. The simulated scenarios showed that some critical aspects contributed decisively to the global sustainability. These critical aspects are not easily identified if only the traditional economical, environmental and risk analysis are applied. (author)

  15. Caracterização de sistemas de banco de dados espaciais para analise de desempenho

    OpenAIRE

    Walter Paulo Costenaro

    1997-01-01

    Resumo: Nesta dissertação, a área de sistemas de banco de dados espaciais é enfocada utilizando a técnica de benchmark para análise de desempenho. Esta técnica requer o monitoramento de sistemas de banco de dados utilizando banco de dados e carga de trabalho (transações) reais ou sintéticos. Vários fatores apontam como ideal o uso de dados sintéticos que melhor representem situações normalmente encontradas em aplicações práticas (reais). Esta dissertação utiliza-se de dados reais (convenciona...

  16. Políticas Públicas: Uma analise mais apurada sobre Governança e Governabilidade

    Directory of Open Access Journals (Sweden)

    Maria Eloisa Cavalheiro

    2009-07-01

    Full Text Available Este ensaio teórico analisou os conceitos e direcionamentos a estudos sobre políticas públicas, governabilidade e governança. O grande desafio do Brasil continua sendo a modernização e, o desenvolvimento econômico, social e político, com descentralização. Várias experiências inovadoras de governança no Brasil, ao longo das últimas décadas, revelaram um alto grau de eficiência na desprivatização do poder público, na democratização do processo decisório ou ainda na reversão de práticas clientelistas. Em todo o mundo, se percebe alta centralidade na vida política, econômica, social e cultural de seus respectivos países. Averiguou-se as características do despotismo aliando seu exercício às práticas políticas, bem como identificamos o termo “política”, sua forma de atuação nos diferentes palcos sociais através dos tempos.

  17. Políticas Públicas: Uma analise mais apurada sobre Governança e Governabilidade

    Directory of Open Access Journals (Sweden)

    Maria Eloisa Cavalheiro

    2015-05-01

    Full Text Available Este ensaio teórico analisou os conceitos e direcionamentos a estudos sobre políticas públicas, governabilidade e governança. O grande desafio do Brasil continua sendo a modernização e, o desenvolvimento econômico, social e político, com descentralização. Várias experiências inovadoras de governança no Brasil, ao longo das últimas décadas, revelaram um alto grau de eficiência na desprivatização do poder público, na democratização do processo decisório ou ainda na reversão de práticas clientelistas. Em todo o mundo, se percebe alta centralidade na vida política, econômica, social e cultural de seus respectivos países. Averiguou-se as características do despotismo aliando seu exercício às práticas políticas, bem como identificamos o termo “política”, sua forma de atuação nos diferentes palcos sociais através dos tempos.

  18. Mortalidade por acidentes de motocicleta no Brasil: analise de tendencia temporal, 1996-2009

    Directory of Open Access Journals (Sweden)

    Evandro Tostes Martins

    2013-10-01

    Full Text Available OBJETIVO Analisar a tendência da mortalidade por acidentes de motocicleta no Brasil. MÉTODOS Estudo descritivo de séries temporais sobre a taxa de mortalidade de acidentes de motocicleta no Brasil, segundo unidades federativas e faixas etárias entre 1996 e 2009. Os dados de óbitos foram obtidos no Sistema de Informação sobre Mortalidade do Ministério da Saúde e da população no Instituto Brasileiro de Geografia Estatística. Taxas de mortalidade padronizadas foram calculadas no período para o Brasil como um todo e Unidades Federativas. Variações anuais das taxas de mortalidade foram estimadas pelo método de Prais-Winsten de regressão linear. RESULTADOS A taxa de mortalidade por acidentes de motocicleta aumentou de 0,5 para 4,5/100.000 habitantes de 1996 a 2009 (aumento de 800% no período e 19% ao ano. Estados com maiores taxas em 2009 foram: Piauí, Tocantins, Sergipe e Mato Grosso. As maiores taxas de crescimento foram observadas nos Estados das regiões Norte, Nordeste e Centro-Oeste. CONCLUSÕES Houve grande aumento das taxas de mortalidade por acidente de motocicleta em todo o Brasil no período, principalmente nos Estados do Nordeste.

  19. Methodology for reactor core physics analysis - part 2; Metodologia de analise fisica do nucleo - etapa 2

    Energy Technology Data Exchange (ETDEWEB)

    Ponzoni Filho, P; Fernandes, V B; Lima Bezerra, J de; Santos, T I.C.

    1992-12-01

    The computer codes used for reactor core physics analysis are described. The modifications introduced in the public codes and the technical basis for the codes developed by the FURNAS utility are justified. An evaluation of the impact of these modifications on the parameter involved in qualifying the methodology is included. (F.E.). 5 ref, 7 figs, 5 tabs.

  20. New geomechanical developments for reservoir management; Desenvolvimentos experimentais e computacionais para analises geomecanicas de reservatorio

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Antonio C.; Menezes Filho, Armando Prestes; Silvestre, Jose R. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The common assumption that oil is produced under a constant rate only considering reservoir depletion has been questioned for some time. An usual hypothesis is that the physical properties of a reservoir are not constants during time, but they vary according to the properties of reservoir rock and the characteristics of the external loads. More precisely, as soon as a reservoir is explored, the volume of fluid diminishes, decreasing the static pressure and increasing the effective stress over the rock skeleton, which, depending on the nature of rock, can lead to a gradual deformation and alteration of reservoir's porosity and permeability, and oil productivity as well. This paper aims at showing numerical and experimental achievements, developed by the Well bore Engineering Technology Department of CENPES, devoted to the characterization of the influence of stress-strain states on the permeability and production of reservoir rocks. It is believed that these developments can possibly bring some light to the understanding of this complex phenomenon, besides allowing the establishment of more realistic relations involving stress-strain-permeability in coupled fluid dynamic problems. (author)

  1. [Analises of the mortality in aged in an Internal Medicine Department].

    Science.gov (United States)

    Cinza Sanjurjo, S; Cabarcos Ortiz de Barrón, A; Nieto Pol, E; Torre Carballada, J A

    2007-02-01

    To establish the characteristics of the deceased and the death causes. Transversal study descriptive, with intake patients elder than 65 years old in an Internal Medicine Department. The variables analized were: age, sex, intake date, discharge date, days of hospital stay, chronic disease previous, admission cause, deceased, diagnoses. The statistical analysis was performed with measures of central tendency and of standard deviation, Chi-cuadrado, Mann-Whitney-Wilcoxon and Kruskal-Wallis. During the revised year, there are 770 patients intaked in Internal Medicine Department and 128 exitus (16.6%). The global average death age was 78.3 +/- 1.3 years: 53.1% (0.44-0.62; p = 0.48) were men and 46.9% were women. The average death intake days was 13.3 +/- 1.7 days (p < 0.001), 3.9% died in less than forty-eight hours after hospitalization. The most frequent admission cause was: dyspnea (46.1%). The most frequent chronic diseases were: ischemic and hypertensive heart disease (18.8%) and chronic obstructive pulmonary disease. The most frequent death cause was respiratory tract infection (43.8%). The prevalence cardiac and pulmonary disease prevalence is high, these diseases are the of the most frequent causes hospital mortality.

  2. Test and analysis of four solar cookers; Analise e teste de quatro fogoes solares

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Paulo Cesar da Costa [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica], e-mail: PauloCPinheiro@ufmg.br, e-mail: pinheiro@demec.ufmg.br

    2006-07-01

    Solar cookers are an alternative to cooking, milk pasteurization and water purification. This paper describes the assemblage and operational data of 4 solar cookers, two greenhouse type and two concentrator type. It is also propose a methodology for solar cookers tests. (author)

  3. Analysis of integrity and risk for onshore pipelines; Analise de integridade e risco para dutos onshore

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Marco Aurelio [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The increasing expansion of the oil and gas industry in Brazil, the current legal requirements relating to security, health and environment in the industrial installations, is necessary that the companies, responsible by the operation of pipelines for oil and gas transport, adopt efficient techniques to assure the operational continuity of these of trustworthy form and insurance. To fulfill this important function it is important that the companies implement a management program to control and register the integrity of the pipelines during the all operational life cycle. Inside of this context of management of the integrity of pipelines, the DNV developed the software ORBIT Pipeline with the intention to serve as an important tool to monitor the technique and security condition of the pipeline, to define the frequency and content technician of the inspection program and to recommend the work of intervention or repair in pipeline when necessary. Additionally to these activities that are carried through directly in the ORBIT Pipeline, also an evaluation of the activity of third part and the land/soil movement is made inside of the systematic for analysis of integrity and risk for onshore pipelines performed by DNV. (author)

  4. Circuito eletrico equivalente para conversores assincronos lineares : analise da força propulsora

    OpenAIRE

    Renato Crivellari Creppe

    1992-01-01

    Resumo: A proposta desta Tese é estudar o funcionamento dos Conversores Assíncronos Lineares, através de um circuito elétrico equivalente que leve em conta todas as particularidades deste tipo de conversor. O conversor é estudado a partir de um modelo matemático unidimensional que estabelece o comportamento da densidade de campo magnético no entreferro do mesmo, possibilitando a determinação de um fator para correção de efeito ligado ao comprimento finito de seu circuito magnético. Outrosfato...

  5. Embedded Systems

    Indian Academy of Sciences (India)

    Embedded system, micro-con- troller ... Embedded systems differ from general purpose computers in many ... Low cost: As embedded systems are extensively used in con- .... operating systems for the desktop computers where scheduling.

  6. Thermal systems; Systemes thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Lalot, S. [Valenciennes Univ. et du Hainaut Cambresis, LME, 59 (France); Lecoeuche, S. [Ecole des Mines de Douai, Dept. GIP, 59 - Douai (France)]|[Lille Univ. des Sciences et Technologies, 59 - Villeneuve d' Ascq (France); Ahmad, M.; Sallee, H.; Quenard, D. [CSTB, 38 - Saint Martin d' Heres (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Gascoin, N.; Gillard, P.; Bernard, S. [Laboratoire d' Energetique, Explosion, Structure, 18 - Bourges (France); Gascoin, N.; Toure, Y. [Laboratoire Vision et Robotique, 18 - Bourges (France); Daniau, E.; Bouchez, M. [MBDA, 18 - Bourges (France); Dobrovicescu, A.; Stanciu, D. [Bucarest Univ. Polytechnique, Faculte de Genie Mecanique (Romania); Stoian, M. [Reims Univ. Champagne Ardenne, Faculte des Sciences, UTAP/LTM, 51 (France); Bruch, A.; Fourmigue, J.F.; Colasson, S. [CEA Grenoble, Lab. Greth, 38 (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Voicu, I.; Mare, T.; Miriel, J. [Institut National des Sciences Appliquees (INSA), LGCGM, IUT, 35 - Rennes (France); Galanis, N. [Sherbrooke Univ., Genie Mecanique, QC (Canada); Nemer, M.; Clodic, D. [Ecole des Mines de Paris, Centre Energetique et Procedes, 75 (France); Lasbet, Y.; Auvity, B.; Castelain, C.; Peerhossaini, H. [Nantes Univ., Ecole Polytechnique, Lab. de Thermocinetiquede Nantes, UMR-CNRS 6607, 44 (France)

    2005-07-01

    This session about thermal systems gathers 26 articles dealing with: neural model of a compact heat exchanger; experimental study and numerical simulation of the thermal behaviour of test-cells with walls made of a combination of phase change materials and super-insulating materials; hydraulic and thermal modeling of a supercritical fluid with pyrolysis inside a heated channel: pre-dimensioning of an experimental study; energy analysis of the heat recovery devices of a cryogenic system; numerical simulation of the thermo-hydraulic behaviour of a supercritical CO{sub 2} flow inside a vertical tube; mixed convection inside dual-tube exchangers; development of a nodal approach with homogenization for the simulation of the brazing cycle of a heat exchanger; chaotic exchanger for the cooling of low temperature fuel cells; structural optimization of the internal fins of a cylindrical generator; a new experimental approach for the study of the local boiling inside the channels of exchangers with plates and fins; experimental study of the flow regimes of boiling hydrocarbons on a bundle of staggered tubes; energy study of heat recovery exchangers used in Claude-type refrigerating systems; general model of Carnot engine submitted to various operating constraints; the free pistons Stirling cogeneration system; natural gas supplied cogeneration system with polymer membrane fuel cell; influence of the CRN coating on the heat flux inside the tool during the wood unrolling process; transport and mixture of a passive scalar injected inside the wake of a Ahmed body; control of a laser welding-brazing process by infrared thermography; 2D self-adaptative method for contours detection: application to the images of an aniso-thermal jet; exergy and exergy-economical study of an 'Ericsson' engine-based micro-cogeneration system; simplified air-conditioning of telephone switching equipments; parametric study of the 'low-energy' individual dwelling; brief synthesis of

  7. Data Systems vs. Information Systems

    OpenAIRE

    Amatayakul, Margret K.

    1982-01-01

    This paper examines the current status of “hospital information systems” with respect to the distinction between data systems and information systems. It is proposed that the systems currently existing are incomplete data dystems resulting in ineffective information systems.

  8. Pedagoginio bendradarbiavimo plėtotė mokykloje: sisteminio tyrimo prielaidos

    OpenAIRE

    Kontautienė, Regina

    2001-01-01

    The system of pedagogic collaboration on basis of development achieves a new qualitative modality in case its character is systematic and interactive. Development of pedagogic collaboration system is possible by subjects; and groups’ participation and creating new opportunities to develop social competence. Pedagogic collaboration is analised by discussing its qualitative modality in such school links: students-pedagogue, pedagogues- schools administration, school pedagogues-parents and etc.,...

  9. EXPERT SYSTEMS

    OpenAIRE

    Georgiana Marin; Mihai Catalin Andrei

    2011-01-01

    In recent decades IT and computer systems have evolved rapidly in economic informatics field. The goal is to create user friendly information systems that respond promptly and accurately to requests. Informatics systems evolved into decision assisted systems, and such systems are converted, based on gained experience, in expert systems for creative problem solving that an organization is facing. Expert systems are aimed at rebuilding human reasoning on the expertise obtained from experts, sto...

  10. Analysis of reactor installation accident WWER-1000 caused by collector head rupture of steam generator

    International Nuclear Information System (INIS)

    Sviridenko, I.I.

    2005-01-01

    System classification of passive heat defence of nuclear dangerous objects with usage of heat pipes. The article is continuation of series of works devoted to research and development of promising passive cooling system of nuclear dangerous objects which use evaporating-condensing heat transfer devices of closed type - heat pipes and two-phase thermosyphons. Classification of autonomous systems of passive heat defence with usage low temperature heat tubes is given. Base classificational lectures are observed. Advantages n disadvantages of various circuit (scheme) solutions are analyzed

  11. Utilising heat from nuclear waste for space heating

    International Nuclear Information System (INIS)

    Deacon, D.

    1982-01-01

    A heating unit utilising the decay heat from irradiated material comprises a storage envelope for the material associated with a heat exchange system, means for producing a flow of air over the heat exchange system to extract heat from the material, an exhaust duct capable of discharging the heated air to the atmosphere, and means for selectively diverting at least some of the heated air to effect the required heating. With the flow of air over the heat exchange system taking place by a natural thermosyphon process the arrangement is self regulating and inherently reliable. (author)

  12. Multibody Systems

    DEFF Research Database (Denmark)

    Wagner, Falko Jens

    1999-01-01

    Multibody Systems is one area, in which methods for solving DAEs are of special interst. This chapter is about multibody systems, why they result in DAE systems and what kind of problems that can arise when dealing with multibody systems and formulating their corresponding DAE system....

  13. System dynamics

    International Nuclear Information System (INIS)

    Kim, Do Hun; Mun, Tae Hun; Kim, Dong Hwan

    1999-02-01

    This book introduces systems thinking and conceptual tool and modeling tool of dynamics system such as tragedy of single thinking, accessible way of system dynamics, feedback structure and causal loop diagram analysis, basic of system dynamics modeling, causal loop diagram and system dynamics modeling, information delay modeling, discovery and application for policy, modeling of crisis of agricultural and stock breeding products, dynamic model and lesson in ecosystem, development and decadence of cites and innovation of education forward system thinking.

  14. Coupling component systems towards systems of systems

    OpenAIRE

    Autran , Frédéric; Auzelle , Jean-Philippe; Cattan , Denise; Garnier , Jean-Luc; Luzeaux , Dominique; Mayer , Frédérique; Peyrichon , Marc; Ruault , Jean-René

    2008-01-01

    International audience; Systems of systems (SoS) are a hot topic in our "fully connected global world". Our aim is not to provide another definition of what SoS are, but rather to focus on the adequacy of reusing standard system architecting techniques within this approach in order to improve performance, fault detection and safety issues in large-scale coupled systems that definitely qualify as SoS, whatever the definition is. A key issue will be to secure the availability of the services pr...

  15. Systems effectiveness

    CERN Document Server

    Habayeb, A R

    1987-01-01

    Highlights three principal applications of system effectiveness: hardware system evaluation, organizational development and evaluation, and conflict analysis. The text emphasizes the commonality of the system effectiveness discipline. The first part of the work presents a framework for system effectiveness, partitioning and hierarchy of hardware systems. The second part covers the structure, hierarchy, states, functions and activities of organizations. Contains an extended Appendix on mathematical concepts and also several project suggestions.

  16. Auxiliary systems

    International Nuclear Information System (INIS)

    Meyer, P.J.

    1981-01-01

    Systems included under the heading ''Reactor Auxillary Systems'' are those immediately involved with the reactor operation. These include the systems for dosing and letdown of reactor coolant, as well as for the chemical dosing, purification and treatment of the reactor coolant and the cooling system in the controlled area. The ancillary systems are mainly responsible for liquid and gaseous treatment and the waste treatment for final storage. (orig.)

  17. Bitcoin System

    Directory of Open Access Journals (Sweden)

    Jan Lánský

    2017-06-01

    Full Text Available Cryptocurrency systems are purely digital and decentralized systems that use cryptographic principles to confirm transactions. Bitcoin is the first and also the most widespread cryptocurrency. The aim of this article is to introduce Bitcoin system using a language understandable also to readers without computer science education. This article captures the Bitcoin system from three perspectives: internal structure, network and users. Emphasis is placed on brief and clear definitions (system components and their mutual relationships. A new system view of the stated terms constitutes author’s own contribution.

  18. JOSHUA system

    International Nuclear Information System (INIS)

    Honeck, H.C.

    1975-04-01

    A major computational system called JOSHUA has been under development at the Savannah River Laboratory since 1968. The JOSHUA System has two major parts: the Operating System and the Application System. The Operating System has been in production use since 1970 and provides data management, terminal, and job execution facilities. The Application System uses these facilities in solving problems in reactor physics and engineering. Features of the Application System are the two-dimensional lattice physics and three-dimensional transient reactor physics capabilities, which have been in use since 1971 and 1974, respectively. The capabilities of the JOSHUA System are summarized, and statistics on size, use, and development effort are provided. (U.S.)

  19. Systems thinking.

    Science.gov (United States)

    Cabrera, Derek; Colosi, Laura; Lobdell, Claire

    2008-08-01

    Evaluation is one of many fields where "systems thinking" is popular and is said to hold great promise. However, there is disagreement about what constitutes systems thinking. Its meaning is ambiguous, and systems scholars have made diverse and divergent attempts to describe it. Alternative origins include: von Bertalanffy, Aristotle, Lao Tsu or multiple aperiodic "waves." Some scholars describe it as synonymous with systems sciences (i.e., nonlinear dynamics, complexity, chaos). Others view it as taxonomy-a laundry list of systems approaches. Within so much noise, it is often difficult for evaluators to find the systems thinking signal. Recent work in systems thinking describes it as an emergent property of four simple conceptual patterns (rules). For an evaluator to become a "systems thinker", he or she need not spend years learning many methods or nonlinear sciences. Instead, with some practice, one can learn to apply these four simple rules to existing evaluation knowledge with transformative results.

  20. Cognitive Systems

    DEFF Research Database (Denmark)

    The tutorial will discuss the definition of cognitive systems as the possibilities to extend the current systems engineering paradigm in order to perceive, learn, reason and interact robustly in open-ended changing environments. I will also address cognitive systems in a historical perspective...... to be modeled within a limited set of predefined specifications. There will inevitably be a need for robust decisions and behaviors in novel situations that include handling of conflicts and ambiguities based on the capability and knowledge of the artificial cognitive system. Further, there is a need...... in cognitive systems include e.g. personalized information systems, sensor network systems, social dynamics system and Web2.0, and cognitive components analysis. I will use example from our own research and link to other research activities....

  1. Crystal Systems.

    Science.gov (United States)

    Schomaker, Verner; Lingafelter, E. C.

    1985-01-01

    Discusses characteristics of crystal systems, comparing (in table format) crystal systems with lattice types, number of restrictions, nature of the restrictions, and other lattices that can accidently show the same metrical symmetry. (JN)

  2. Filter systems

    International Nuclear Information System (INIS)

    Vanin, V.R.

    1990-01-01

    The multidetector systems for high resolution gamma spectroscopy are presented. The observable parameters for identifying nuclides produced simultaneously in the reaction are analysed discussing the efficiency of filter systems. (M.C.K.)

  3. Expert systems

    International Nuclear Information System (INIS)

    Haldy, P.A.

    1988-01-01

    The definitions of the terms 'artificial intelligence' and 'expert systems', the methodology, areas of employment and limits of expert systems are discussed. The operation of an expert system is described, especially the presentation and organization of knowledge as well as interference and control. Methods and tools for expert system development are presented and their application in nuclear energy are briefly addressed. 7 figs., 2 tabs., 6 refs

  4. Expert System

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas Troels; Cattani, Gian Luca

    2016-01-01

    An expert system is a computer system for inferring knowledge from a knowledge base, typically by using a set of inference rules. When the concept of expert systems was introduced at Stanford University in the early 1970s, the knowledge base was an unstructured set of facts. Today the knowledge b...... for the application of expert systems, but also raises issues regarding privacy and legal liability....

  5. Packaged solar water heating technology: twenty years of progress

    International Nuclear Information System (INIS)

    Morrison, Graham; Wood, Byard

    2000-01-01

    The world market for packaged solar water heaters is reviewed, and descriptions are given of the different types of solar domestic water heaters (SDWH), design concepts for packaged SDWH, thermosyphon SDWH, evacuated insulation and excavated tube collectors, seasonally biased solar collectors, heat pump water heaters, and photovoltaic water heaters. The consumer market value for SDWHs is explained, and the results of a survey of solar water heating are summarised covering advantages, perceived disadvantages, the relative importance of purchase decision factors, experience with system components, and the most frequent maintenance problems. The durability, reliability, and performance of SDWHs are discussed

  6. Retrofitting Systems

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    This report gives an overview of the different retrofitting possibilities that are available today. The report looks at both external and internal systems for external wall constructions, roof constructions, floor constructions and foundations. All systems are described in detail in respect to use...... and methods, and the efficiency of the different systems are discussed....

  7. Multifunction system

    International Nuclear Information System (INIS)

    Wauthier, J.; Fiori, R.

    1990-01-01

    The development, the characteristics and the applications of a multifunction system are presented. The system is used on the RBES laboratory pipes, at Marcoule. The system was developed in order to allow, without time loss, the modification of the circuit function by replacing only one component. The following elements form the multifunction system: a fixed base, which is part of the tube, a removable piece, which is inserted into the base, a cover plate and its locking system. The material, chosen among commercial trade marks, required small modifications in order to be used in the circuit [fr

  8. Operating systems

    CERN Document Server

    Tsichritzis, Dionysios C; Rheinboldt, Werner

    1974-01-01

    Operating Systems deals with the fundamental concepts and principles that govern the behavior of operating systems. Many issues regarding the structure of operating systems, including the problems of managing processes, processors, and memory, are examined. Various aspects of operating systems are also discussed, from input-output and files to security, protection, reliability, design methods, performance evaluation, and implementation methods.Comprised of 10 chapters, this volume begins with an overview of what constitutes an operating system, followed by a discussion on the definition and pr

  9. Systems integration.

    Science.gov (United States)

    Siemieniuch, C E; Sinclair, M A

    2006-01-01

    The paper presents a view of systems integration, from an ergonomics/human factors perspective, emphasising the process of systems integration as is carried out by humans. The first section discusses some of the fundamental issues in systems integration, such as the significance of systems boundaries, systems lifecycle and systems entropy, issues arising from complexity, the implications of systems immortality, and so on. The next section outlines various generic processes for executing systems integration, to act as guides for practitioners. These address both the design of the system to be integrated and the preparation of the wider system in which the integration will occur. Then the next section outlines some of the human-specific issues that would need to be addressed in such processes; for example, indeterminacy and incompleteness, the prediction of human reliability, workload issues, extended situation awareness, and knowledge lifecycle management. For all of these, suggestions and further readings are proposed. Finally, the conclusions section reiterates in condensed form the major issues arising from the above.

  10. Ternary systems

    International Nuclear Information System (INIS)

    Kagan, D.N.; Hubberstey, P.; Barker, M.G.

    1985-01-01

    The paper reviews the experimental and theoretical studies carried out on multicomponent alkali metal systems. Solid-liquid phase equilibria studies are mainly concerned with the systems Na-K-Rb and Na-K-Cs, and data on the liquidus temperatures in these systems are presented. The thermodynamic properties of the ternary Na-K-Cs eutectic system have been determined experimentally, and the enthalpy, heat capacity and excess functions of the alloy are given. An analysis of calculational methods used in determining thermodynamic functions of ternary liquid metals systems is described. Finally, data are tabulated for the density, compressibility, saturated vapour pressure, viscosity and thermal conductivity of the ternary Na-K-Cs eutectic system. (UK)

  11. Recommender systems

    CERN Document Server

    Kembellec, Gérald; Saleh, Imad

    2014-01-01

    Acclaimed by various content platforms (books, music, movies) and auction sites online, recommendation systems are key elements of digital strategies. If development was originally intended for the performance of information systems, the issues are now massively moved on logical optimization of the customer relationship, with the main objective to maximize potential sales. On the transdisciplinary approach, engines and recommender systems brings together contributions linking information science and communications, marketing, sociology, mathematics and computing. It deals with the understan

  12. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  13. Systems Engineering

    OpenAIRE

    Vaughan, William W.

    2016-01-01

    The term “systems engineering” when entered into the Google search page, produces a significant number of results, evidence that systems engineering is recognized as being important for the success of essentially all products. Since most readers of this item will be rather well versed in documents concerning systems engineering, I have elected to share some of the points made on this subject in a document developed by the European Cooperation for Space Standardization (ECSS), a component of t...

  14. Energetic Systems

    Data.gov (United States)

    Federal Laboratory Consortium — The Energetic Systems Division provides full-spectrum energetic engineering services (project management, design, analysis, production support, in-service support,...

  15. Intelligent systems

    CERN Document Server

    Irwin, J David

    2011-01-01

    Technology has now progressed to the point that intelligent systems are replacing humans in the decision making processes as well as aiding in the solution of very complex problems. In many cases intelligent systems are already outperforming human activities. Artificial neural networks are not only capable of learning how to classify patterns, such images or sequence of events, but they can also effectively model complex nonlinear systems. Their ability to classify sequences of events is probably more popular in industrial applications where there is an inherent need to model nonlinear system

  16. Systemic darwinism.

    Science.gov (United States)

    Winther, Rasmus Grønfeldt

    2008-08-19

    Darwin's 19th century evolutionary theory of descent with modification through natural selection opened up a multidimensional and integrative conceptual space for biology. We explore three dimensions of this space: explanatory pattern, levels of selection, and degree of difference among units of the same type. Each dimension is defined by a respective pair of poles: law and narrative explanation, organismic and hierarchical selection, and variational and essentialist thinking. As a consequence of conceptual debates in the 20th century biological sciences, the poles of each pair came to be seen as mutually exclusive opposites. A significant amount of 21st century research focuses on systems (e.g., genomic, cellular, organismic, and ecological/global). Systemic Darwinism is emerging in this context. It follows a "compositional paradigm" according to which complex systems and their hierarchical networks of parts are the focus of biological investigation. Through the investigation of systems, Systemic Darwinism promises to reintegrate each dimension of Darwin's original logical space. Moreover, this ideally and potentially unified theory of biological ontology coordinates and integrates a plurality of mathematical biological theories (e.g., self-organization/structure, cladistics/history, and evolutionary genetics/function). Integrative Systemic Darwinism requires communal articulation from a plurality of perspectives. Although it is more general than these, it draws on previous advances in Systems Theory, Systems Biology, and Hierarchy Theory. Systemic Darwinism would greatly further bioengineering research and would provide a significantly deeper and more critical understanding of biological reality.

  17. Avaliação da fertilidade dos solos de sistemas agroflorestais com cafeeiro (Coffea arabica L. em Lavras-MG Evaluation of soil fertility in agroforest systems with coffee trees (Coffea arabica L. in Lavras-MG

    Directory of Open Access Journals (Sweden)

    Bruno Grandi Salgado

    2006-06-01

    Full Text Available Com o objetivo de avaliar a fertilidade dos solos em um sistema agroflorestal composto por cafeeiros (Coffea arábica L. - Mundo Novo, ingazeiros (Inga vera Willd e grevíleas (Grevilea robusta A. Cunn, situado em Lavras, Minas Gerais, foi instalado o presente experimento. Usou-se um delineamento experimental inteiramente casualizado com três tratamentos e sete repetições. Os tratamentos foram: a cafeeiros a pleno sol, b cafeeiros consorciados com ingazeiros e c cafeeiros consociados com grevílea. Os espaçamentos dos cafeeiros nos três sistemas foi 4 x 1 m, para o ingazeiro 8 m x 15 m e para a grevílea 12 m x 10 m. Aos 15 anos de idade do cafeeiro e do ingazeiro e aos 9 anos da grevílea foram avaliadas as seguintes características dos solos, pH, acidez potencial (H+Al, alumínio trocável (Al+3, bases trocáveis (Ca+2 e Mg+2, potássio disponível (K+, fósforo disponível(P, enxofre (S, CTC efetiva (T, soma de bases (SB, saturação de bases (V e matéria orgânica (MO. Os resultados foram submetidos à analise de variância e as médias, comparadas pelo teste de Scott-Knott. Após a análise dos dados, concluiu-se que, embora tenha havido diferenças entre alguns elementos estudados, as características químicas dos solos nos três sistemas não foram severamente afetadas.The objective of this wark was to evaluat e the soil fertility in an agroforest system using coffee trees (Coffea arabica L - Mundo Novo, inga trees (Inga vera Wild and grevillea trees (Grevillea robusta A Cunn situated in Lavras, Minas Geris. A completely randomized experimental design with tree treatments and seven replicates was utilized. The treatments were : a coffee trees in full sunshine; b coffee trees mixed with inga trees and c coffee trees mixed with grevillea trees. Tree spacings in the three systems were 4 x 1m for coffee, 8 m x 15 m for inga and 12 x 10 m for grevillea. With coffee and inga trees at 15 years of age and grevillea trees at 9 years of age

  18. Experimental analysis of the natural convection system through a closed loop under transient regime

    International Nuclear Information System (INIS)

    Lavrador, Marcelo de Bastos; Braga, Carlos Valois Maciel; Carajilescov, Pedro

    1996-01-01

    This work presents the experimental model used in the study of closed loop natural convection (thermosyphons). Details of the main circuit and information on the used instrumentation are also presented. The study aimed the circuit thermal performance, initially justifying the oscillatory behaviour of the time vs. temperature curves. As expected, the curves for the cold leg presented an oscillation amplitude lesser than those for hot leg since the 'peaks' which reveal high temperature spots disappear due to the heat transfer to the cooling water. Those curves were not influenced within the measured range, by the changes occurred in the cooling water flow (secondary circuit). Besides, when varying the power supplied by the hot source it was observed a variation directly proportional of the oscillation frequency, of the oscillation amplitude, and the difference between the hot and cold legs temperatures. Concerning to the forced power variations, it is observed that the oscillation is always restarted and the final results are related to the second applied power

  19. Caste System

    OpenAIRE

    Hoff, Karla

    2016-01-01

    In standard economics, individuals are rational actors and economic forces undermine institutions that impose large inefficiencies. The persistence of the caste system is evidence of the need for psychologically more realistic models of decision-making in economics. The caste system divides South Asian society into hereditary groups whose lowest ranks are represented as innately polluted. ...

  20. Recommender systems

    OpenAIRE

    Lu L.; Medo M.; Yeung C.H.; Zhang Y.-C.; Zhang Z.-K.; Zhou T.

    2012-01-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article...

  1. GEOMASS system

    International Nuclear Information System (INIS)

    Ohyama, Takuya; Saegusa, Hiromitsu

    2009-03-01

    As a part of the research and development regarding characterisation of deep geological environment, the GEOMASS (GEOLOGICAL MODELLING ANALYSIS AND SIMULATION SOFTWARE) system has been developed by the Japan Atomic Energy Agency in order to carry out geological and hydrogeological modelling and groundwater flow simulation and so on. The GEOMASS system integrates a commercial geological interpretation system (EarthVision), which is used for geological modelling and visualisation, with a proprietary code for groundwater flow (FracAffinity). This integrated system allows users to make rapid improvement of models as data increases. Also, it is possible to perform more realistic groundwater flow simulation due to the capability of modelling the rock mass as a continuum with discrete hydro-structural features in the rock mass. This paper consists of 'Overview of GEOMASS system', FracAffinity Theoretical Background' and 'FracAffinity User Guide' and is edited as a GEOMASS system manual. 'Overview of GEOMASS system' describes the outline of this system. 'FracAffinity Theoretical Background' describes the information of technical background of FracAffinity software. FracAffinity User Guide' describes the structure of the FracAffinity input files, the usage of FracAffinity Interface and flow-solver. Updating of the FracAffinity has been continued as needed and FracAffinity version3.3 is the latest version at present (July 2008). (author)

  2. Systems integration (automation system). System integration (automation system)

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K; Komori, T; Fukuma, Y; Oikawa, M [Nippon Steal Corp., Tokyo (Japan)

    1991-09-26

    This paper introduces business activities on an automation systems integration (SI) started by a company in July,1988, and describes the SI concepts. The business activities include, with the CIM (unified production carried out on computers) and AMENITY (living environment) as the mainstays, a single responsibility construction ranging from consultation on structuring optimal systems for processing and assembling industries and intelligent buildings to system design, installation and after-sales services. With an SI standing on users {prime} position taken most importantly, the business starts from a planning and consultation under close coordination. On the conceptual basis of structuring optimal systems using the ompany {prime}s affluent know-hows and tools and adapting and applying with multi-vendors, open networks, centralized and distributed systems, the business is promoted with the accumulated technologies capable of realizing artificial intelligence and neural networks in its background, and supported with highly valuable business results in the past. 10 figs., 1 tab.

  3. Creative Systems

    DEFF Research Database (Denmark)

    Manelius, Anne-Mette; Beim, Anne

    2007-01-01

    Opsamling af diskussioner på konferencen og udstillingen Creative Systems i september/oktober 2007. Konferencen og Udstillingen Creative Systems sætter fokus på systemer som en positiv drivkraft i den kreative skabelsesproces. CINARK inviterede fire internationale kapaciteter, som indenfor hver...... deres felt har beskæftiget sig med udviklingen af systemer. Kieran Timberlake, markant amerikansk tegnestue; Mark West, Professor på University of Manitoba, Canada, og pioner indenfor anvendelse af tekstilforskalling til betonstøbninger; Matilda McQuaid, Arkitekturhistoriker og kurator på udstillingen...... om Extreme Textiles på amerikanske Cooper Hewit Design Museum, samt Professor Ludger Hovestadt, ved ETH, Zürich der fokuserer på udvikling og anvendelse af logaritmiske systemtilgange. Udstillingen diskuterede ud fra deres meget forskellige arbejder, det kreative potentiale i anvendelsen af systemer...

  4. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  5. Upgraded RECOVER system - CASDAC system

    International Nuclear Information System (INIS)

    Yamamoto, Yoichi; Koyama, Kinji

    1992-03-01

    The CASDAC (Containment And Surveillance Data Authenticated Communication) system has been developed by JAERI for nuclear safeguards and physical protection of nuclear material. This system was designed and constructed as an upgraded RECOVER system, design concept of which was based on the original RECOVER system and also the TRANSEAVER system. Both of them were developed several years ago as a remote monitoring system for continual verification of security and safeguards status of nuclear material. The system consists of two subsystems, one of them is a Grand Command Center (GCC) subsystem and the other is a facility subsystem. Communication between the two subsystems is controlled through the international telephone line network. Therefore all communication data are encrypted to prevent access by an unauthorized person who may intend to make a falsification, or tapping. The facility subsystem has an appropriate measure that ensure data security and reliable operation under unattended mode of operator. The software of this system is designed so as to be easily used in other different types of computers. This report describes the outline of the CASDAC system and the results of its performance test. This work has been carried out in the framework of Japan Support Programme for Agency Safeguards (JASPAS) as a project, JA-1. (author)

  6. Comparative analysis of Nb and Ti addition in the Cu-11,8%wt.Al-0,5%wt.Be e Cu-11,8%wt.Al-3,0%wt.Ni shape memory alloy; Analise comparativa da adicao de NB e TI nas ligas Cu-11,8Al-0,5Be e Cu-11,8Al-3,0Ni passiveis do efeito memoria de forma

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, M.Q. da; Oliveira, G.D. de, E-mail: manoel.quirino@ufersa.edu.br [Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro, RN (Brazil)

    2014-07-01

    The system of the Cu-Al alloys shape memory alloy have been the subject of many studies due to a wide range of possible applications and relatively low cost, and the chemical composition of the main factors that determine the properties of these properties. This work analyzed the influence of Nb and Ti elements in Cu-11,8Al-0,5Be and Cu-11,8Al-3,0Ni alloy. The alloys are obtained by melting and passed through homogenizing heat treatment followed by water quenching at 30°C. The samples were characterized by Microscopy Optical, X-ray Diffraction and Microhardness testing. The alloys showed fine precipitates of second phase homogeneously distributed in the matrix that provides improvement in the properties of these alloys. (author)

  7. Watchdog System

    DEFF Research Database (Denmark)

    Madsen, Tanja Kidholm Osmann; Bahnsen, Chris Holmberg; Jensen, Morten Bornø

    This deliverable is part of WP4. Overall WP4 is motivated by the need for automatic systems that can ease the task of annotating massive amounts of traffic data. Concretely this deliverable is related to WP4.2 - the watchdog system. The idea with the watchdog is to develop a system that can remov...... huge chunks of video data where no events/interactions of interest are occurring and hence let a user focus on manually annotation of only the interesting stuff....

  8. Dynamical systems

    CERN Document Server

    Sternberg, Shlomo

    2010-01-01

    Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the

  9. Water systems

    International Nuclear Information System (INIS)

    Riess, R.

    1980-01-01

    The present paper describes the coolant chemistry and its consequences for 1300 MWsub(e) KWU PWR plants. Some selected systems, i.e. primary heat transport system, steam water cycle and cooling water arrangements, are chosen for this description. Various aspects of coolant chemistry regarding general corrosion, selective types of corrosion and deposits on heat transfer surfaces have been discussed. The water supply systems necessary to fulfill the requirements of the coolant chemistry are discussed as well. It has been concluded that a good operating performance can only be achieved when - beside other factors - the water chemistry has been given sufficient consideration. (orig./RW)

  10. Water systems

    International Nuclear Information System (INIS)

    Riess, R.

    1981-01-01

    The present paper describes the coolant chemistry and its consequences for 1300 MWsub(e) KWU PWR plants. Some selected systems, i.e. primary heat transport system, steam water cycle and cooling water arrangements, are chosen for this description. Various aspects of coolant chemistry regarding general corrosion, selective types of corrosion and deposits on heat transfer surface have been discussed. The water supply systems necessary to fulfill the requirements of the coolant chemistry are discussed as well. It has been concluded that a good operating performance can only be achieved when - beside other factors - the water chemistry has been given sufficient consideration. (orig./RW)

  11. Imaging system

    International Nuclear Information System (INIS)

    Froggatt, R.J.

    1981-01-01

    The invention provides a two dimensional imaging system in which a pattern of radiation falling on the system is detected to give electrical signals for each of a plurality of strips across the pattern. The detection is repeated for different orientations of the strips and the whole processed by compensated back projection. For a shadow x-ray system a plurality of strip x-ray detectors are rotated on a turntable. For lower frequencies the pattern may be rotated with a Dove prism and the strips condensed to suit smaller detectors with a cylindrical lens. (author)

  12. Kaonic systems

    Directory of Open Access Journals (Sweden)

    Oset E.

    2012-12-01

    Full Text Available I make a short review of the situation of the kaonic systems, with novel information supporting the two Λ(1405 states from the K-d → nπΣ reaction. A review is made of the K¯$ar K$NN system with recent calculations converging to smaller bindings and larger widths. Novel systems involving two kaons and one nucleon or three kaons are also reported and finally a short discussion is made of the analogous state DNN for which recent studies find a large binding and a small width.

  13. The systems integration modeling system

    International Nuclear Information System (INIS)

    Danker, W.J.; Williams, J.R.

    1990-01-01

    This paper discusses the systems integration modeling system (SIMS), an analysis tool for the detailed evaluation of the structure and related performance of the Federal Waste Management System (FWMS) and its interface with waste generators. It's use for evaluations in support of system-level decisions as to FWMS configurations, the allocation, sizing, balancing and integration of functions among elements, and the establishment of system-preferred waste selection and sequencing methods and other operating strategies is presented. SIMS includes major analysis submodels which quantify the detailed characteristics of individual waste items, loaded casks and waste packages, simulate the detailed logistics of handling and processing discrete waste items and packages, and perform detailed cost evaluations

  14. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  15. Septic Systems

    Science.gov (United States)

    The web site provides guidance and technical assistance for homeowners, government officials, industry professionals, and EPA partners about how to properly develop and manage individual onsite and community cluster systems that treat domestic wastewater.

  16. Respiratory system

    Science.gov (United States)

    Bartlett, R. G., Jr.

    1973-01-01

    The general anatomy and function of the human respiratory system is summarized. Breathing movements, control of breathing, lung volumes and capacities, mechanical relations, and factors relevant to respiratory support and equipment design are discussed.

  17. Bubble systems

    CERN Document Server

    Avdeev, Alexander A

    2016-01-01

    This monograph presents a systematic analysis of bubble system mathematics, using the mechanics of two-phase systems in non-equilibrium as the scope of analysis. The author introduces the thermodynamic foundations of bubble systems, ranging from the fundamental starting points to current research challenges. This book addresses a range of topics, including description methods of multi-phase systems, boundary and initial conditions as well as coupling requirements at the phase boundary. Moreover, it presents a detailed study of the basic problems of bubble dynamics in a liquid mass: growth (dynamically and thermally controlled), collapse, bubble pulsations, bubble rise and breakup. Special emphasis is placed on bubble dynamics in turbulent flows. The analysis results are used to write integral equations governing the rate of vapor generation (condensation) in non-equilibrium flows, thus creating a basis for solving a number of practical problems. This book is the first to present a comprehensive theory of boil...

  18. Systems Biology

    Indian Academy of Sciences (India)

    IAS Admin

    study and understand the function of biological systems, particu- larly, the response of such .... understand the organisation and behaviour of prokaryotic sys- tems. ... relationship of the structure of a target molecule to its ability to bind a certain ...

  19. Bricks / Systems

    DEFF Research Database (Denmark)

    At first glance, this book may appear eclectic. It contains writings from architectural practice in a language and structure based on subjective views and experiences, combined with research contributions based on systematic design investigations of discrete computational systems. Discussions range......, and it aims to illustrate and identify new modes of working in architecture, particularly with regards to brickwork and other complex systems of modular assemblies, whether physical or digital....

  20. Expert Systems

    OpenAIRE

    Lucas, P.J.F.

    2005-01-01

    Expert systems mimic the problem-solving activity of human experts in specialized domains by capturing and representing expert knowledge. Expert systems include a knowledge base, an inference engine that derives conclusions from the knowledge, and a user interface. Knowledge may be stored as if-then rules, orusing other formalisms such as frames and predicate logic. Uncertain knowledge may be represented using certainty factors, Bayesian networks, Dempster-Shafer belief functions, or fuzzy se...