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.

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

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.)

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.

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.

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.

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)

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)

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

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

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

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°

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

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)

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

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

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.

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

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

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.

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.

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

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

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)

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)

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

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.

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

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.

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.

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.

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

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.

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.

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.

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.

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.

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

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).

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.

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.

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

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.

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.

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

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.

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)

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

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

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

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.

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)

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.

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...

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

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.

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...

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)

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)

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

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

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.

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

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.

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.

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 ...

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

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

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.

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.

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...

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%).

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.

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

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.

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.

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.

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)

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

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.

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.

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)

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.

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)

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.

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.

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...

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.

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.

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

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)

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.

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.

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

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.

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

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...

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.

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.

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.

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)

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).

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)

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)

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 ...

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

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.

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)

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.

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)

Site selection for nuclear power plants and geologic seismologia influence

International Nuclear Information System (INIS)

Castro Feitosa, G. de.

1985-01-01

The site selection for nuclear power plants is analised concerning to the process, methodology and the phases in an overall project efforts. The factors affecting are analised on a general viewpoint, showing the considerations given to every one. The geologic and seismologic factors influence on the foundation design are more detailed analised, with required investigation and procedures accordingly sub-soil conditions in the site [pt

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.

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)

Revisão sistemática de Promitobates Roewer 1913 e análise filogenética de Mitobatinae Simon1879 (Arachnida, Opiliones, Gonyleptidae)

OpenAIRE

Cibele Bragagnolo

2009-01-01

As 10 especies nominais de Promitobates foram utilizadas na analise cladistica da subfamilia Mitobatinae. A especie P. ornatus (Mello-Leitao, 1922), amplamente distribuida e polimorfica, foi decomposta em quatro unidades monomorficas e sua taxonomia testada durante a analise cladistica. Outras duas especies que apresentaram polimorfismos (P. hatschbachi H. Soares, 1945 e P. viridigranulatus Soares & Soares, 1946) tambem foram separadas em duas unidades distintas. A analise cladistica foi efet...

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.

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

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.

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

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

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

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

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

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.

DCDM1: Lessons Learned from the World's Most Energy Efficient Data Center

Energy Technology Data Exchange (ETDEWEB)

Sickinger, David E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Van Geet, Otto D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Carter, Thomas [Johnson Controls

2018-05-03

This presentation discusses the holistic approach to design the world's most energy-efficient data center, which is located at the U.S. Department of Energy National Renewable Energy Laboratory (NREL). This high-performance computing (HPC) data center has achieved a trailing twelve-month average power usage effectiveness (PUE) of 1.04 and features a chiller-less design, component-level warm-water liquid cooling, and waste heat capture and reuse. We provide details of the demonstrated PUE and energy reuse effectiveness (ERE) and lessons learned during four years of production operation. Recent efforts to dramatically reduce the water footprint will also be discussed. Johnson Controls partnered with NREL and Sandia National Laboratories to deploy a thermosyphon cooler (TSC) as a test bed at NREL's HPC data center that resulted in a 50% reduction in water usage during the first year of operation. The Thermosyphon Cooler Hybrid System (TCHS) integrates the control of a dry heat rejection device with an open cooling tower.

An Innovative Enhanced Wall to Reduce the Energy Demand in Buildings

Science.gov (United States)

Fantozzi, F.; Filipeschi, S.; Mameli, M.; Nesi, S.; Cillari, G.; Mantelli, M. B. H.; Milanez, F. H.

2017-01-01

Energy saving in buildings is one of most important issues for European countries. Although in the last years many studies have been carried out in order to reach the zero-consumption house the energy rate due to passive solar heating could be further enhanced. This paper proposes a method for increasing the energy rate absorbed by opaque walls by using a two phase loop thermosyphon connecting the internal and the external façade of a prefabricated house wall. The evaporator zone is embedded into the outside facade and the condenser is indoor placed to heat the domestic environment. The thermosyphon has been preliminary designed and implanted into a wall for a prefabricated house in Italy. An original dynamic thermal model of the building equipped with the thermosyphon wall allowed the evolution of the indoor temperature over time and the energy saving rates. The transient behaviour of the building has been simulated during the winter period by using the EnergyPlusTM software. The annual saving on the heating energy is higher than 50% in the case of a low consumption building.

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.

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

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

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.,...

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.

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)

Bio-mass stimulated absorption refrigerator for food storage in Papua New Guinea

Energy Technology Data Exchange (ETDEWEB)

Uppal, A.H.; Komuna, K.K. (University of Technology, Papua (New Guinea). Dept. of Mechanical Engineering)

1992-01-01

A medium capacity (140 litre) water-ammonia absorption refrigerator, thermally stimulated by a charcoal-stove is being developed to store food in remote locations and island communities of Papua New Guinea. The paper describes a prototype charcoal or biomass-stove thermal refrigerator in which the absorption cycle and thermo-syphonic cycle of a heating liquid has been coupled in a novel and straight forward approach. The system consisted of a heat-exchanger, in the form of a jacket surrounding the generator tube of a water-ammonia absorption cycle refrigerator, and was connected in a close-pipe work loop to a heat exchanger placed in a charcoal-stove. A heat-transfer oil flowed due to thermo-syphonic forces between the heat exchanger and the jacket. According to initial tests it took 4 hours for the system to warm up, and took another 7 hours for water in the freezer cabinet to approach 0{sup o}C from an initial 25{sup o}C. The cooling capacity of the evaporator was roughly 70% of the cooling capacity of the original system with electric heating. For a twelve hour test the stove consumed 2.5 kg of charcoal with an air port opening between 3 to 5 millimeters. Preliminary estimates indicate that the described prototype absorption unit stimulated by the wood/coconut husk stove (rather than electricity/kerosene), when manufactured commercially will cost less than US 1500 dollars at 1991 prices. (Author).

Development of the RRR cold neutron beam facility

International Nuclear Information System (INIS)

Lovotti, Osvaldo; Masriera, Nestor; Lecot, Carlos; Hergenreder, Daniel

2002-01-01

This paper describes some general design issues on the neutron beam facilities (cold neutron source and neutron beam transport system) of the Replacement Research Reactor (RRR) for the Australian Nuclear Science and Technology Organisation (ANSTO). The description covers different aspect of the design: the requirements that lead to an innovative design, the overall design itself, the definition of a technical approach in order to develop the necessary design solutions, and finally the organizational framework by which international expertise from five different institutions is integrated. From the technical viewpoint, the RRR-CNS is a liquid Deuterium (LD2) moderator, sub-cooled to ensure maximum moderation efficiency, flowing within a closed natural circulation thermosyphon loop. The thermosyphon is surrounded by a zirconium alloy CNS vacuum containment that provides thermal insulation and a multiple barriers scheme to prevent Deuterium from mixing with water or air. Consistent with international practice, this vessel is designed to withstand any hypothetical energy reaction should Deuterium and air mix in its interior. The 'cold' neutrons are then taken by the NBTS and transported by the neutron guide system into the reactor beam hall and neutron guide hall, where neutron scattering instruments are located. From the management viewpoint, the adopted distributed scheme is successful to manage the complex interfacing between highly specialized technologies, allowing a smooth integration within the project. (author)

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.

Gravity Scaling of a Power Reactor Water Shield

International Nuclear Information System (INIS)

Reid, Robert S.; Pearson, J. Boise

2008-01-01

Water based reactor shielding is being considered as an affordable option for potential use on initial lunar surface reactor power systems. Heat dissipation in the shield from nuclear sources must be rejected by an auxillary thermal hydraulic cooling system. The mechanism for transferring heat through the shield is natural convection between the core surface and an array of thermosyphon radiator elements. Natural convection in a 100 kWt lunar surface reactor shield design has been previously evaluated at lower power levels (Pearson, 2006). The current baseline assumes that 5.5 kW are dissipated in the water shield, the preponderance on the core surface, but with some volumetric heating in the naturally circulating water as well. This power is rejected by a radiator located above the shield with a surface temperature of 370 K. A similarity analysis on a water-based reactor shield is presented examining the effect of gravity on free convection between a radiation shield inner vessel and a radiation shield outer vessel boundaries. Two approaches established similarity: 1) direct scaling of Rayleigh number equates gravity-surface heat flux products, 2) temperature difference between the wall and thermal boundary layer held constant on Earth and the Moon. Nussult number for natural convection (laminar and turbulent) is assumed of form Nu = CRa n . These combined results estimate similarity conditions under Earth and Lunar gravities. The influence of reduced gravity on the performance of thermosyphon heat pipes is also examined

NUTRITIOUS – HEALING STRUCTURE OF SOME KINDS OF HONEY IN EASTERN CROATIA

Directory of Open Access Journals (Sweden)

Zvonimir Tucak

2000-06-01

Full Text Available Honey as food and honey as medicine are for a long time in peoples use. The nutritious and healing substances are different, also of the honey-herbs which the bees visit. The analised kind of honey (Acacia, Flower honey, linden-honey showw a real richnes in healing and nutritious structure. The organoleptic and chemical features of the analised honey- types fit into the standards of Republic Croatia and the Europian Unit. The said exhibitors justificate the hitherto way of bee-keeping and the technology of honey-production.

Design and manufacture of ceramic heat pipes for high temperature applications

International Nuclear Information System (INIS)

Meisel, Peter; Jobst, Matthias; Lippmann, Wolfgang; Hurtado, Antonio

2015-01-01

Heat exchangers based on ceramic heat pipes were designed for use under highly abrasive and corrosive atmospheres at temperatures in the range of 800–1200 °C for high-temperature power-engineering applications. The presented heat pipes are gravity assisted and based on a multi-layer concept comprising a ceramic cladding and an inner metal tube that contains sodium as the working fluid. Hermetical encapsulation of the working fluid was achieved by electron-beam welding of the inner metal tube. Subsequently, closure of the surrounding ceramic tube was performed by laser brazing technology using a glass solder. Temperature resistance and functionality of the manufactured ceramic thermosyphons could be confirmed experimentally in a hot combustion gas atmosphere at temperatures up to 1100 °C. The ceramic tubes used had an outer diameter of 22 mm and a total length of 770 mm. The measured axial heat transfer of the ceramic gravity assisted heat pipes at the stationary operating point with cold/hot gas temperature of 100 °C/900 °C was 400 W. The result of the calculation using the created mathematical model amounted to 459 W. - Highlights: • Heat-pipe design consists of a ceramic shell and an inner metallic tube. • Laser brazing technology is suitable to seal ceramic heat-pipes. • Thermal characteristic of double wall thermosyphon was modelled using FEM code. • Experimental investigations demonstrated functionality of double wall thermosyphons

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

To leave from social scenario: on heterogeneity and specifity of populism

Directory of Open Access Journals (Sweden)

Sebastián Barros

2009-12-01

Full Text Available This paper is part of a discussion on the specificity of populism. Taking Laclau’s theorerical framework as a starting point, we analise the importance of the concept of heterogeneity in his argument. Later on, we analise Rancière’s understanding of politics as conflict and conclude that the idea of heterogeneity is central to a definition of populism. In this sense, we argue that heterogenity is something which is moved from its natural place in the order of domination, and starts to be taken as a part in the definition of the commonness of the community. This would have three specific effects over the subsequent political articulations. The inclusion of a heterogeneity would demonstrate the inexistance of the community of equals, forcing the need for a new representation of that community, now incarnated in a subject that, in the name of the past tort, claims to represent the universal plenitude of the community. Finally, we analise interventions by Gramsci and Ortega y Gasset in relation to the irruption of heterogeneity.

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

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.

A study of natural circulation cooling using a flow visualization rig

International Nuclear Information System (INIS)

Bowman, W.C.; Ferch, R.L.; Omar, A.M.

1985-01-01

A flow visualization rig has been built at Monserco Limited to provide visual insight into the thermalhydraulic phenomena which occur during single phase and two phase thermosyphoning in a figure-of-eight heat transport loop. Tests performed with the rig have provided design information for the scaling and instrumentation of a high pressure rig being investigated for simulating CANDU reactor conditions during natural circulation cooling. A videotape was produced, for viewing at this presentation, to show important thermalhydraulic features of the thermosyphoning process. The rig is a standard figure-of-eight loop with two steam generators and three heated channels per pass. An elevated surge tank open to atmosphere was used for pressure control. Two variable speed pumps provided forced circulation for warming up the rig, and for establishing the desired initial conditions for testing. Test rig power could be varied between 0 and 15 kW

Experimental thermal study and numerical simulation of a composite solar wall. Optimization of the energetic performances; Etude thermique experimentale et simulation numerique d`un mur solaire composite. Optimisation des performances energetiques

Energy Technology Data Exchange (ETDEWEB)

Zalewski, L.

1996-11-27

The objective of this work is the analysis of a passive solar component: the composite solar wall, a building component, which includes an insulating panel located behind the massive wall. This panel has two vents located at the top and at the bottom, which allow the air to circulate from the room to the layer in contact with the back of the massive wall, where it is heated, and then back to the room. The solar energy is transferred to the building by conduction through the massive wall, and then by convection using a thermosyphon phenomenon. The monitoring of 2 solar houses in Verdun-Thierville (Meuse, France) has clearly shown, control issues of the air layer. The wall must be operated as autonomously as possible, to not be a constraint for the occupants and to get an optimization of the energy gains. To solve these problems, a composite solar wall prototype was erected in a test cell at Cadarache and tested in real operating conditions. This allows to use a more complete instrumentation, to have access more easily to the sensors and to study various configurations. The first experiments revealed an inverse thermosyphon phenomenon. To avoid this effect, two systems were designed, tested at Cadarache and then implemented in the walls at Verdun. (author) 77 refs.

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)

A DYNAMIC APPROACH TO IMPROVING THE EXECUTION OF DEVELOPMENT STRATEGIES FOR DATE-RELATED INDUSTRIES IN IRAN, BASED ON HYBRID GRA AND ISM METHODS

Directory of Open Access Journals (Sweden)

S. Ghane

2012-01-01

Full Text Available

ENGLISH ABSTRACT: This paper presents a hybrid Grey Relational Analysis (GRA and Interpretive Structural Modelling (ISM methodology for appropriate dynamic analysis, in order to improve the execution of development strategies for date-related industries in Iran. The proposed framework consists of four main phases: (1 establishment of strategies; (2 GRA analysis; (3 binary comparison to determine hierarchy levels using the ISM method; and (4 dynamic analysis. The analysis reveals that the strategic priorities to improve Iran’s date industries can be arranged on three levels. The first level consists of the by-products of date packing and processing. On the second level, three tactics are determined: developing ready-for-use date products, deriving date fruit products, and fermentation of products. The third level is to blend dates with other foods and palm products (excluding dates.

AFRIKAANSE OPSOMMING: Hierdie artikel hou ’n hibirede GRA en ISM metodologie voor vir dinamiese analise om ont-wikkelingstrategieë vir die dadelindustrie in Iran te verbeter. Die voorgestelde raamwerk bestaan uit vier fases: (1 vasstelling van die strategieë; (2 GRA analise; (3 binêre vergelyking om die hierargievlakke te bepaal deur die ISM metode te gebruik; en (4 dinamiese analise. Die analise toon dat die strategiese prioriteite om die dadelindustrie in Iran te verbeter in drie vlakke gerangskik kan word. Die eerste vlak behels die neweprodukte van dadelverpakking en -prosessering. Op die tweede vlak word drie taktieke ontwikkel: die ontwikkeling van gereed-vir-gebruik dadelprodukte, dadelvrugteprodukte en die fermentasie van produkte. Die derde vlak behels die versny van dadels met ander voedsel- en palmprodukte (uitgesonderd dadels.

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

A solar collector for air-conditioning

Energy Technology Data Exchange (ETDEWEB)

Kose, E. [Microtherm Energietechnik GmbH, 25 - Lods (France)

1999-03-01

A high performance Compound Parabolic Concentrator (CPC) collector is presented. It comprises dewar type tubular vacuum tubes with an absorber coating of very low emittance, a moderately concentrating reflector and a simple thermosyphon heat removal system. The reflectors car be designed with respect to the specific needs; reflector material, concentration, truncation and symmetry car be chosen freely. The collector allows the construction of cooling systems with higher COP's without using tracking systems. Land use and costs are greatly reduced. For a certain application (optimum yearly gain in Munich with a constant collector temperature of 180 deg C) the reflector was optimized, it is a fairly asymmetrical design. A symmetrical design with a similar performance has been tested, the results are shown. (author)

Flooding in counter-current two-phase flow

International Nuclear Information System (INIS)

Ragland, W.A.; Ganic, E.N.

1982-01-01

Flooding is a phenomenon which is best described as the transition from counter-current to co-current flow. Early notice was taken of this phenomenon in the chemical engineering industry. Flooding also plays an important role in the field of two-phase heat transfer since it is a limit for many systems involving counter-current flow. Practical applications of flooding limited processes include wickless thermosyphons and the emergency core cooling system (ECCS) of pressurized water nuclear reactors. The phenomenon of flooding also is involved in the behavior of nuclear reactor core materials during severe accident conditions where flooding is one of the mechanisms governing the motion of the molten fuel pin cladding

Flooding in counter-current two-phase flow

Energy Technology Data Exchange (ETDEWEB)

Ragland, W.A.; Ganic, E.N.

1982-01-01

Flooding is a phenomenon which is best described as the transition from counter-current to co-current flow. Early notice was taken of this phenomenon in the chemical engineering industry. Flooding also plays an important role in the field of two-phase heat transfer since it is a limit for many systems involving counter-current flow. Practical applications of flooding limited processes include wickless thermosyphons and the emergency core cooling system (ECCS) of pressurized water nuclear reactors. The phenomenon of flooding also is involved in the behavior of nuclear reactor core materials during severe accident conditions where flooding is one of the mechanisms governing the motion of the molten fuel pin cladding.

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)

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)

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.

De amores desmedidos e narradores irônicos: a (anti heroína romântica e a quebra do lugar-comum

Directory of Open Access Journals (Sweden)

Andrea Trench de Castro

2011-10-01

Full Text Available By the paths of irony, this article aims at elaborating a comparison between three works of Romanticism, whose authors are the Brazilian Joaquim Manuel de Macedo, the Portuguese Camilo Castelo Branco and the English Jane Austen, in order to analise the creation of the romantic female character and the contours of the anti-heroine in this period. We intend to analise the irony, the comic and the parody as procedures that permeate such romantic productions, focusing on the rupture of commonplace and on the critique and reflection that are implied in the quoted concepts, in order to reveal the originality with which such writers surge in the literary scene.

Heat transfer 1990. Proceedings of the ninth international heat transfer conference

International Nuclear Information System (INIS)

Hetsroni, G.

1990-01-01

This book contains the proceedings of the Ninth International Heat Transfer Conference. Included in Volume 3 are the following chapters: Refrigerant vapor condensation on a horizontal tube bundle. Local heat transfer in a reflux condensation inside a closed two-phase thermosyphon and surface temperature by means of a pulsed photothermal effects

Performance modeling and techno-economic analysis of a modular concentrated solar power tower with latent heat storage

Energy Technology Data Exchange (ETDEWEB)

Rea, Jonathan E.; Oshman, Christopher J.; Olsen, Michele L.; Hardin, Corey L.; Glatzmaier, Greg C.; Siegel, Nathan P.; Parilla, Philip A.; Ginley, David S.; Toberer, Eric S.

2018-05-01

In this paper, we present performance simulations and techno-economic analysis of a modular dispatchable solar power tower. Using a heliostat field and power block three orders of magnitude smaller than conventional solar power towers, our unique configuration locates thermal storage and a power block directly on a tower receiver. To make the system dispatchable, a valved thermosyphon controls heat flow from a latent heat thermal storage tank to a Stirling engine. The modular design results in minimal balance of system costs and enables high deployment rates with a rapid realization of economies of scale. In this new analysis, we combine performance simulations with techno-economic analysis to evaluate levelized cost of electricity, and find that the system has potential for cost-competitiveness with natural gas peaking plants and alternative dispatchable renewables.

Dynamic performance of self-operated three-way valve used in a hybrid air conditioner

International Nuclear Information System (INIS)

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

2014-01-01

A hybrid air conditioner combining a thermosyphon cycle with a vapor compression refrigeration cycle has a large energy saving potential compared with a common air conditioner for spaces requiring year-round cooling. The performance of the switch between the vapor compression mode and the thermosyphon mode largely impacts the safety and reliability of hybrid air conditioners. Therefore, a self-operated three-way valve is proposed. A thermodynamic model and a kinetic model are developed in this paper to evaluate the dynamic performance of the switch valve. The effects of the spring force constant, compressor discharging volume, fit clearance and piston length on the dynamic performance of the switch valve are analyzed. In conclusion, the proposed self-operated three-way valve can realize the switch operation accurately. - Highlights: •A self-operated three-way valve is proposed for hybrid air conditioners. •The thermodynamic model and kinetic model of the self-operated three-way valve are developed. •The validity of models is verified by experiments. •Effects of four main design parameters on the operating performance of the valve are researched

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)

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.

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.

Fluid-flow pressure measurements and thermo-fluid characterization of a single loop two-phase passive heat transfer device

Science.gov (United States)

Ilinca, A.; Mangini, D.; Mameli, M.; Fioriti, D.; Filippeschi, S.; Araneo, L.; Roth, N.; Marengo, M.

2017-11-01

A Novel Single Loop Pulsating Heat Pipe (SLPHP), with an inner diameter of 2 mm, filled up with two working fluids (Ethanol and FC-72, Filling Ratio of 60%), is tested in Bottom Heated mode varying the heating power and the orientation. The static confinement diameter for Ethanol and FC-72, respectively 3.4 mm and 1.7mm, is above and slightly under the inner diameter of the tube. This is important for a better understanding of the working principle of the device very close to the limit between the Loop Thermosyphon and Pulsating Heat Pipe working modes. With respect to previous SLPHP experiments found in the literature, such device is designed with two transparent inserts mounted between the evaporator and the condenser allowing direct fluid flow visualization. Two highly accurate pressure transducers permit local pressure measurements just at the edges of one of the transparent inserts. Additionally, three heating elements are controlled independently, so as to vary the heating distribution at the evaporator. It is found that peculiar heating distributions promote the slug/plug flow motion in a preferential direction, increasing the device overall performance. Pressure measurements point out that the pressure drop between the evaporator and the condenser are related to the flow pattern. Furthermore, at high heat inputs, the flow regimes recorded for the two fluids are very similar, stressing that, when the dynamic effects start to play a major role in the system, the device classification between Loop Thermosyphon and Pulsating Heat Pipe is not that sharp anymore.

THE EFFECT OF THE AQUEOUS EXTRACT OF THE LEAVES OF ...

African Journals Online (AJOL)

Administrator

Histopathology of the testes of treated rats revealed marked degeneration of germinal ..... Analise histological de testiculose semen de caes submedicos a administracao de ... (2001). High risk of infertility and long term gonadal damage in.

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)

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)

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

Purchase aspects playing a part in the broad selection of solar boiler types

International Nuclear Information System (INIS)

Van Amerongen, G.A.H.

1996-01-01

Because of the large variety of solar water heaters in the Netherlands and abroad the arguments to purchase such boilers have to be reconsidered. In this article a few practical guidelines are given, focusing on solar boilers equipped with thermosyphon collector circuits or enamel steel storage tanks, and some typical aspects of imported solar water heaters. 3 figs., 1 tab., 1 refs

Experimental study of the thermal performance of an assisted-gravity ...

African Journals Online (AJOL)

The experimental results showed that the best performances of the thermosyphon are obtained for a power of 100 W, with a corresponding water heat transfer coefficient reaching approximately a maximum of 3000 W/K.m2 for a filling rate of 161% while that of FC-72 does not exceed 1800 W/K.m2 whatever the filling rate is, ...

An introduction to a postmodern approach to nursing research ...

African Journals Online (AJOL)

Vanweë logistiese redes word in hierdie artikel slegs inleidende gedagtes oor diskoers-analise as benadering tot kwalitatiewe, refleksiewe verpleegnavorsing ingesluit. Verskillende postmoderne ";benaderings"; tot kwalitatiewe navorsing word in die verpleegkunde as epistemologie beskryf en het begin wortelskiet.

Por uma sócio-musicologia ancorada na semiologia da enunciação: uma alternativa para o estudo do acontecimento musical urbano na presente modernidade

Directory of Open Access Journals (Sweden)

Regina Marcia Simão Santos

1998-08-01

Full Text Available O objetivo deste artigo é apontar para uma sócio-semiologia em música, na vertente dos estudos de enunciação e analise dos discursos, em resposta a lacunas detectadas nas pesquisas musicológicas. Traz contribuições para a atualização do debate sobre comunicação, ao considerar o funcionamento enunciativo em cada situaçnao concreta de performance, constituído de cena social e cena enunciativa, com dispositivos contextuais e intertextuais postos em jogo na produção e na recepção, gerando sentidos. Conclui pela bénefica adoaçnao deste enfoque metodológico no estudo do acontecimento musical urbano, superando os limites de uma analise estrutural, com seus recortes teóricos, por outra que considere sentidos inscritos no social.

Assessment of thermalhydraulic phenomena for external water make-up

International Nuclear Information System (INIS)

Harwood, C.; Baschuk, J.

2015-01-01

Following the Fukushima Daiichi accident, Canadian NPP licensees implemented a number of changes, including additional provisions for water make-up to the reactor/boiler systems. The CNSC has placed a contract with CNL to model some of the make-up options, focusing on cooling via the boilers to prevent core damage. Such strategies have been credited with sustaining thermo syphoning in the primary system and thus prolonging the available time for the operator to provide pumped make-up to the boilers or emergency coolant injection to the core, thereby maintaining decay heat removal. This paper presents results of CATHENA calculations of an extended loss of all electrical power in which the operator manually depressurizes the boilers by crash-cooling, thus allowing water to flow to the boilers by gravity from the deaerator tank. The rapid cooling of the boilers promotes thermo-syphoning flow in the primary heat transport system and results in a corresponding cool-down and depressurization of this system. (author)

Assessment of thermalhydraulic phenomena for external water make-up

Energy Technology Data Exchange (ETDEWEB)

Harwood, C., E-mail: Christopher.Harwood@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, ON (Canada); Baschuk, J. [Canadian Nuclear Laboratories, Chalk River, ON, (Canada)

2015-07-01

Following the Fukushima Daiichi accident, Canadian NPP licensees implemented a number of changes, including additional provisions for water make-up to the reactor/boiler systems. The CNSC has placed a contract with CNL to model some of the make-up options, focusing on cooling via the boilers to prevent core damage. Such strategies have been credited with sustaining thermo syphoning in the primary system and thus prolonging the available time for the operator to provide pumped make-up to the boilers or emergency coolant injection to the core, thereby maintaining decay heat removal. This paper presents results of CATHENA calculations of an extended loss of all electrical power in which the operator manually depressurizes the boilers by crash-cooling, thus allowing water to flow to the boilers by gravity from the deaerator tank. The rapid cooling of the boilers promotes thermo-syphoning flow in the primary heat transport system and results in a corresponding cool-down and depressurization of this system. (author)

Simulation of natural convection in a rectangular loop using finite elements

International Nuclear Information System (INIS)

Pepper, D.W.; Hamm, L.L.; Kehoe, A.B.

1984-01-01

A two-dimensional finite-element analysis of natural convection in a rectangular loop is presented. A psi-omega formulation of the Boussinesque approximation to the Navier-Stokes equation is solved by the false transient technique. Streamlines and isotherms at Ra = 10 4 are shown for three different modes of heating. The results indicate that corner effects should be considered when modeling flow patterns in thermosyphons

Focalización y modalidad en el "Lanzarote del Lago" (ms. 9611 BNE

Directory of Open Access Journals (Sweden)

Antonio Contreras Martín

2009-12-01

Full Text Available The purpose of this paper is to analise the point of view and the varitions of the speech in Lanzarote del Lago (BNE ms 9611 to observe how the compilator worked the French source, Lancelot en prose.

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)

15N sample preparation for mass spectroscopy analysis

International Nuclear Information System (INIS)

Trivelin, P.C.O.; Salati, E.; Matsui, E.

1973-01-01

Technics for preparing 15 N samples to be analised is presented. Dumas method and oxidation by sodium hypobromite method are described in order to get the appropriate sample. Method to calculate 15 N ratio from mass spectrometry dates is also discussed [pt

The form and function of space in the Jonah narrative in Prudentius Cathemerinon 7.81-175

Directory of Open Access Journals (Sweden)

J. H. Barkhuizen

1988-05-01

Full Text Available In hierdie artikel word ’n analise gemaak van die struktuur en funksie van narratiewe ruimte in die Jona-verhaal sees vertel deur Prudentius (Cathemerinon 1. Hierdie verhaal is gekies omdat dit by uitstek ruimte-georiënteerd is. Die analise is gebaseer op ’n verwerking van die teorie van G. Zoran, wat narratiewe ruimte op tekstuele en plot-vlak ondersoek, Ruimte op tekstuele vlak verwys na die topografiese aard van ruimte, dit wil sê van objekte en plekke, asook die beginsel van die teks-perspektief van sodanige objekte en plekke. Die topografiese aard van ruimte behels weer aspekte soos horisontale en vertikale opposisies, kwaliteitstrukture en ontologiese beginsels. Ruimte op die plot-vlak verwys na sinchroniese en diachroniese relasies. Eersgenoemde het te doen met die beginsel van beweging en rus, terwyl laasgenoemde te doen het met bepaalde rigtinge en intensies op die plot-vlak.

A Designer Fluid For Aluminum Phase Change Devices: Aluminum Inorganic Aqueous Solutions (IAS) Chemistry and Experiments. Volume 2

Science.gov (United States)

2016-11-17

returned from the condenser to the evaporator by a variety of methods. In the simplest implementation of a heat pipe, a thermo-syphon, the walls of the...flow condensation as compared to that with natural convection cooling spread over the entire exposed pipe. The use of an aluminum heat transfer ...a larger thermal resistance throughout the tube. This resistance would work against heat transfer into the evaporator section. Excess permanganate

Perceptions on physiopathology and preferred treatment of epilepsy ...

African Journals Online (AJOL)

Die doelwitte van hierdie studie was om persepsies van epilepsie en asma te analiseer na aanleiding van die toeskrywing van oorsaak, voorgestelde metodes van risikovermindering en verkose behandeling. Die steekproef het 100 deelnemers ingesluit, geselekteer op grond van kwota-steekproeftrekking (10 manlik en 10 ...

MARKETING STRATEGY OF SPONSORSHIP IN SPORT

OpenAIRE

Nebojša Maksimović; Radenko Matić; Svetlana Mihić

2008-01-01

The paper outlines the preparation of sponsorship offer in sport. Analitically, each phase in preparation for sponsorship offer has been analised step by step as well as all necessary actions that marketing team undertakes during the realisation and when the sponsorship program is finished.

Storage arrangements for nuclear fuel

International Nuclear Information System (INIS)

Deacon, D.

1982-01-01

A storage arrangement for spent nuclear fuel either irradiated or pre-irradiated or for vitrified waste after spent fuel reprocessing, comprises a plenum chamber which has a base pierced by a plurality of openings each of which has sealed to it an open topped tube extending downwards and closed at its lower end. The plenum chamber, with the tubes, forms an air-filled enclosure associated with an exhaust system for exhausting air from the system through filters to maintain the interior of the enclosure at sub-atmospheric pressure. The tubes are arranged to accommodate the stored fuel and the arrangement includes a means for producing a flow of cooling air over the exterior of the tubes so that the latter effectively form a plurality of heat exchangers in close proximity to the fuel. The air may be caused to flow over the tube surfaces by a natural thermosyphon process. (author)

Bioclimatic building in Hungary: results of the Pecs house

Energy Technology Data Exchange (ETDEWEB)

Fueloep, L.; Szasz, J. (Pollack Mihaly Coll. of Technology, Pecs (HU))

1990-09-01

The house was designed on a split-level to fit into a slope, with close attention paid to the reduction of heat losses, the increasing of passive gains and the maintenance of bioclimatic comfort. The building's rounded contours reduce turbulence and edge effects. A totally glazed south side incorporates two thermosyphon mass walls as well as a two-storey high sunspace. This unheated intermediate space acts as a buffer between indoors and outdoors and maximises solar gain, which can however be controlled by internal shading. A fan assisted central gravel packed tower and a rock bed floor provide heat storage. There are two 18 m{sup 2} areas of thermosyphon walls, where glass on polycarbonate is used to cover 0.45 m of dark stone mass. In 1989 the glazed wall was retrofitted to incorporate honeycomb transparent insulation, which still allows radiation gain but minimizes heat loss. Transparent insulation is also used in a skylight which is important for lighting the hallway but which would otherwise contribute to heat loss. Natural and forced ventilation as well as a cool air-pond contributes to cooling. Auxiliary floor heating is supplied by gas. In one room underfloor PCM batteries charged by discount night electricity are used for heating. A fireplace is also provided. (author).

MARKETING STRATEGY OF SPONSORSHIP IN SPORT

Directory of Open Access Journals (Sweden)

Nebojša Maksimović

2008-08-01

Full Text Available The paper outlines the preparation of sponsorship offer in sport. Analitically, each phase in preparation for sponsorship offer has been analised step by step as well as all necessary actions that marketing team undertakes during the realisation and when the sponsorship program is finished.

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)

Theory and design of heat exchanger : shell and tube condenser and reboiler

International Nuclear Information System (INIS)

Min, Ui Dong

1996-02-01

This book gives descriptions of shell and tube heat exchanger including from, sorts, structure like shell and shell side, channel, and sliding bar, basic design of heat exchanger, flow-induced vibration, shell side condenser, tube side condenser and design of basic structure of condenser by types, selection of reboiler type, kettle type reboiler, internal reboiler, pump through reboiler, design of reboiler like kettle and internal reboiler, and horizontal and vertical thermosyphon reboiler.

Natural circulation in a scaled PWR integral test facility

International Nuclear Information System (INIS)

Kiang, R.L.; Jeuck, P.R. III

1987-01-01

Natural circulation is an important mechanism for cooling a nuclear power plant under abnormal operating conditions. To study natural circulation, we modeled a type of pressurized water reactor (PWR) that incorporates once-through steam generators. We conducted tests of single-phase natural circulations, two-phase natural circulations, and a boiler condenser mode. Because of complex geometry, the natural circulations observed in this facility exhibit some phenomena not commonly seen in a simple thermosyphon loop

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)

The cold neutron facility of the JRR-3M

International Nuclear Information System (INIS)

Kumai, T.; Suzuki, M.; Kakefuda, K.

1992-01-01

A description is given of a cold neutron source and neutron guide tubes of the JRR-3M. The installation of the cold neutron source (CNS) together with the neutron guide system is one of the principal objectives of the remodeling project of the JRR-3 and this CNS is the first one that was installed in the high neutron flux reactors of 14 orders of magnitude in Japan. The CNS is a liquid hydrogen moderator and vertical thermosyphon type. It mainly consists of a hydrogen plant for liquid hydrogen and helium refrigerator plant for cold helium gas. Five neutron guide tubes are installed to get thermal and cold neutron beams in the beam hall. The CNS and the guide tubes have been operated very well since August 1990. (author)

USSR Report, Political and Sociological Affairs, No. 1406, Selections from Soviet Foreign Policy Journals.

Science.gov (United States)

1983-05-09

34 Sistema industrial e exportacao de manufacturados: analise da experiencia brasileira," Rio de Janeiro, 1971, p 120; ’Anuario estadistico do Brasil...growth rates of food production. It is inseparably related to the concept of "poverty." Poor people are the constant companions of capitalism. All

Turkish Banking Sector Credit-Deposit Developments Regionally Analysis (2005-2011

Directory of Open Access Journals (Sweden)

Adalet HAZAR

2013-06-01

Full Text Available Banking sector takes over the mediation function between fund suppliers and demand. So by the time the financial system gets deeper, banking sector involves to the dinamics and becomes a vital part of economic growth. In our country which expressed as having insufficiant savings, regionally analising in 2005-2011 period developments is the purpose of this study. On the numerical estimations, in spite of having more capacity to purchase parity, big cities shows a higher performance for savings. However especially the cities in the regions of East and Southeast Anatolia, purchase capacity parity is lower and savings are under their own costs.

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

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

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

LA DINÁMICA DE FLUIDOS COMPUTACIONAL, SU APLICACIÓN AL ESTUDIO DE LAS CARACTERÍSTICAS DE UN INTERCAMBIADOR DE TUBOS TÉRMICOS

Directory of Open Access Journals (Sweden)

David Fernández Rivas

2005-09-01

Full Text Available Para el estudio y el diseño de un intercambiador de calor del tipo Termosifón se emplea por primera vez enCuba una novedosa técnica de modelación numérica, la Dinámica de Fluidos Computacional, uso quepudiera ahorrar al país numerosos recursos. Este trabajo continua, con nuevos aportes, una largainvestigación que ha tenido como objetivo central, la instalación de tubos térmicos termosifón (ITTT. Lasimulación computacional, es una poderosa herramienta que se emplea para conocer parámetros de interésen la operación de dicha instalación. Se trabaja con programas de Dinámica de Fluidos Computacional(DFC para acortar el tiempo de experimentación y ahorrar recursos materiales y humanos durante elestudio de diferentes variantes de arreglos geométricos de los tubos térmicos. Se logran conocer lasparticularidades que los diferentes arreglos de tubos introducen al proceso de intercambio de calor. Esteresultado brinda una importante contribución para la futura construcción de un termosifón a escalaindustrial. Esta investigación ha suscitado mucho interés por lo que pudiera significar para la eficiencia de lacaldera las nuevas condiciones impuestas por la quema de combustible cubano.Palabras Claves: Dinámica de Fluidos Computacional, Tubos térmicos, termosifón.__________________________________________________________________________AbstractThe Computational Fluids Dynamic it is used for studying a thermosyphon heat exchanger like a noveltechnique of numeric modeling, for the first time in Cuba. This technique could save a lot of resources. Thiswork is the continuation of a long research in the heat pipes technology. Working with Computational FluidsDynamic (DFC programs, consumes less time in the experimentation and allows saving material andhuman resources for these studies. It is possible to know many particularities of different geometries of tubesarrangements. This investigation will guarantee a future thermosyphon

フロリナートによる高出力ICチップの液体冷却に関する実験的研究

OpenAIRE

儀間, 悟; 富村, 寿夫; 張, 興; 藤井, 丕夫

1999-01-01

Fluorinert cooling of high-power IC chips using a closed type thermosyphon loop is investigated fundamentally to cope with the recent rapid rise in heat dissipation density of notebook computers. The present experimental set-up consists of evaporator and condenser sections connected by flexible tubing. The evaporator section corresponds to a high-power IC chip, and the condenser section represents a cooling plate located behind a display of notebook computers. The evaporator has the size of 5...

Convection in complex shaped vessel; Convection dans des enceintes de forme complexe

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The 8 november 2000, the SFT (Societe Francaise de Thermique) organized a technical day on the convection in complex shaped vessels. Nine papers have been presented in the domains of the heat transfers, the natural convection, the fluid distribution, the thermosyphon effect, the steam flow in a sterilization cycle and the transformers cooling. Eight papers are analyzed in ETDE and one paper dealing with the natural convection in spent fuels depository is analyzed in INIS. (A.L.B.)

BOOST QUALITY OF ENGINEERING PROJECT SOLUTIONS THROUGH ECONOMIC ANALYSIS AND COMPARING ALTERNATIVES

Directory of Open Access Journals (Sweden)

Milan Vukčević

2008-12-01

Full Text Available In this paper the principles and applications of money-time relationships are given. Economic profitability of engineering projects, using more methodes is analised. On the bases those methodes, comparing mutually exclusive alternatives of projects was done, because of optimization of decision. The emphasized theoretical states in this paper are applicated.

Uit genade alleen? Herbesinning oor die Romeinebrief deur Suid ...

African Journals Online (AJOL)

Die kritiek (verwyt!) dat hierdie benadering agter- haald is, word ondervang deurdat sy analise, sintese en toepassing verder ook nog vanuit die perspektief van die retoriese situasie van Romeine (bl 17v) benader is. Met behulp van 'n literêr-kritiese paradigma van verstaan van die Romeinebrief vra hy die belangrike vraag ...

Mechanisms of beryl flotation: a literature review

International Nuclear Information System (INIS)

Torem, M.L.

1988-01-01

This paper shows a review about the investigations that have been done on the mechanisms of flotation of beryl and its dependence in relation to the presence of fluoride species. It is also analised the anionic flotation of the mineral and the effect of cations in the pulp of flotation. (author) [pt

The marketing of solar energy

International Nuclear Information System (INIS)

Coehoorn, M.; Sinke, W.C.

1994-01-01

After two decades of research and development the market introduction of solar water heaters finally is developing rapidly. In a number of progressive countries, amongst which the Netherlands, preparations are made for the large-scale introduction of photovoltaic (PV) power systems. A brief overview is given of market introduction activities with regard to solar energy applications in several countries. Also attention is paid to new technological developments for the improvement of solar boilers: the Integrated Collector Storage system, the integration of the storage tank in the solar water heater (combi-boiler), and the new principle for a combined system for the production of hot tap water and space heating, the so-called solar-gas-combi. The Dutch-developed boilers, however, must compete with the the foreign thermosyphon boilers, although these boilers probably require more maintenance than the Dutch boilers. The market for PV-systems is still in its infancy. The marketing efforts and research activities in Japan, USA and European countries for PV-systems are briefly discussed. Although financial incentives from the national governments are still necessary contributions from other market parties for the development of PV-systems are expected. 4 ills

A reading of calvino’s The castle of crossed destinies as a machine-text

Directory of Open Access Journals (Sweden)

Otávio Guimarães Tavares

2011-06-01

Full Text Available This text has the objective of analising the compositinal processo of Italo Calvino’s work The Castle of Crossed Destinies as a machine-text, as a textual production that, through restrictions to the creative process, lends combinatorial procedures from tarot cards and mechanical processes as a means of expanding compositional possibilities.

Métodos cromatográficos para determinar aminas biogênicas em alimentos de origem animal

Directory of Open Access Journals (Sweden)

César Aquiles Lázaro de la Torre

2013-12-01

Full Text Available Aminas biogenicas sao formadas como resultado da descarboxilacao de aminoacidos livres especificos. A analise desses metabolitos e de grande importancia na determinacao da qualidade e monitoramento de biogenicas como histamina e tiramina relacionadas com episodios de intoxicacao em humanos. A cromatografia e uma tecnica de separacao química usada para caracterizar aminas biogenicas. Variacoes da tecnica (cromatografia liquida, em camada delgada e gasosa tem sido amplamente usadas, porem a complexidade da matriz alimentar faz com que sejam realizadas mudancas nos processos de extracao, derivatizacao e deteccao em concordancia com cada grupo de alimento. A cromatografia liquida de alta eficiencia (CLAE e o metodo mais utilizado na determinacao de aminas biogenicas em alimentos. Contudo, devido a importancia das aminas biogenicas no controle da qualidade e a seguranca do consumidor, os pesquisadores tentam desenvolver novos metodos com o intuito de uma analise mais rapida e precisa para o controle de alimentos no mercado. O objetivo da revisao e apresentar algumas tecnicas cromatograficas aplicadas no monitoramento de aminas biogenicas em produtos de origem animal.

Heritage, sacredness and power: on different categories of historical and cultural patrimony in Brazil

Directory of Open Access Journals (Sweden)

Aline Sapiezinskas Krás Borges Canani

Full Text Available This article deals with the concept of heritage present in the public policies of cultural, artistic and historical heritage preservation, aiming to widen the apprehension of the concept. Bringing examples from my fieldwork in Venezianos Lane, in Porto Alegre, my purpose in this article is to analise the attribution of values to specific buildings, objects or processes as a way to produce new meanings within the different contexts in which it occurs, observing specially the construction of signification from the point of view of familiar heritage, heritage objects seen as sacred properties and the dimension of power involved in such process. Considering the ressignifications which resulted from the heritage acknoledgement, I analise the different categories perceived by the city inhabitants who are involved with the heritage, not in a passive way, but owning the capacity to construct new significances and to give meaning to the world around them. I try to underline the symbolic dimension present in this process in which the property acquires a meaning and comes to be considered heritage.

Traditional African economies in conflict with western capitalism

Directory of Open Access Journals (Sweden)

C.M. Pauw

1996-04-01

Full Text Available Traditional Mrican economies� in conflict with western capitalism Some of� the fundamental differences between two� economic systems which, by� and large,� have� come� into� conflict with� one another� in Africa south� of the� Sahara� are� analised,� i e� traditional African� economies� and western, capitalist oriented� economies.� The� dire� economic� conditions prevailing� in Africa are the result,� to a� large extent,� of� a� long history of� exploitation and economic� disempowerment particularly� by� western� powers.� Not� all� the strategies and programs to� counter this poverty are equally appropriate or acceptable.� In� the� meantime� a� unique� coping� mechanism� is� developing, particularly within African Independent Churches which may provide some answers.

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.

Energy and exergy analysis of photovoltaic-thermal collector with and without glass cover

International Nuclear Information System (INIS)

Chow, T.T.; Pei, G.; Fong, K.F.; Lin, Z.; Chan, A.L.S.; Ji, J.

2009-01-01

In photovoltaic-thermal (PV/T) technology, the use of glass cover on the flat-plate hybrid solar collector is favorable to the photothermic process but not to the photovoltaic process. Because of the difference in the usefulness of electricity and thermal energy, there is often no straight forward answer on whether a glazed or unglazed collector system is more suitable for a specific application. This glazing issue was tackled in this paper from the viewpoint of thermodynamics. Based on experimental data and validated numerical models, a study of the appropriateness of glass cover on a thermosyphon-based water-heating PV/T system was carried out. The influences of six selected operating parameters were evaluated. From the first law point of view, a glazed PV/T system is found always suitable if we are to maximize the quantity of either the thermal or the overall energy output. From the exergy analysis point of view however, the increase of PV cell efficiency, packing factor, water mass to collector area ratio, and wind velocity are found favorable to go for an unglazed system, whereas the increase of on-site solar radiation and ambient temperature are favorable for a glazed system

Characterization of lithium niobate monocrystals doped with iron (Li Nb O3:Fe)

International Nuclear Information System (INIS)

Mastelaro, V.R.; Terrile, N.C.; Nascimento, O.R.; Nicolo, I.

1988-01-01

LiNbO 3 :Fe Crystals were analised using EPR Optical absorption spectroscopy and holographic techniques. The site occupied by Fe 3+ is discused and the effect of thermal treatments on Fe 2+ and OH - concentration is studied. The high diffraction efficiency, measure by holographic techniques shows that crystals are particularly good for holographic applications. (author) [pt

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)

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.

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)

Dossier: renewable energies for heat production; Dossier: energies renouvelables pour la production de chaleur

Energy Technology Data Exchange (ETDEWEB)

Anon.

2002-09-01

This dossier makes a state-of-the-art of today's applications of renewable energy sources in the residential, collective and tertiary sectors for the space heating and the hot water production. In France, three energy sources profit by a particularly favorable evolution: the solar thermal, the wood fuel and the geothermal energies. In these sectors, the offer of reliable and technically achieved appliances has been considerably widen thanks to the impulse of some French and German manufacturers. Part 1 - solar thermal: individual solar water heaters (monobloc, thermosyphon with separate tank, forced circulation systems, auxiliary heating systems); combined solar systems (direct heating floor, system with storage); collective solar systems for hot water production (receivers, efficiency, heat storage and transfer, auxiliary heating, decentralized systems); heating of open-air swimming pools; some attempts in air-conditioning; the warranty of results. Part 2 - wood fuels: domestic space heating (log boilers, installation rules, hydro-accumulation, automatic boilers); collective and tertiary wood-fueled heating plants (design of boiler plants, fuel supply, combustion chamber, smoke purification systems, ash removal, regulation system), fuels for automatic collective plants, design and installation rules. Part 3 - geothermal energy: different types (water-source and ground-source heat pumps, financial incentive). (J.S.)

In situ performance curves measurements of large pumps

International Nuclear Information System (INIS)

Anton, A

2010-01-01

The complex energetic system on the river Lotru in Romania comprises of a series of lakes and pumping stations and a major hydroelectric power plant: Lotru-Ciunget. All the efforts have been oriented towards the maintenance of the Pelton turbines and very little attention has been directed to the pumps. In the system, there are three large pumping stations and only in the last 5 years, the pump performances have become a concern. The performances where determined using portable ultrasonic flow meters, a Yates meter, precision manometers and appropriate electrical equipment for power measurement (Power Analiser - NORMA D4000 LEM). The measurements are not supposed to interfere with the normal operation so only a limited number of tests could be performed. Based on those tests, portions of the test curves have been measured and represented in specific diagrams.

In situ performance curves measurements of large pumps

Science.gov (United States)

Anton, A.

2010-08-01

The complex energetic system on the river Lotru in Romania comprises of a series of lakes and pumping stations and a major hydroelectric power plant: Lotru-Ciunget. All the efforts have been oriented towards the maintenance of the Pelton turbines and very little attention has been directed to the pumps. In the system, there are three large pumping stations and only in the last 5 years, the pump performances have become a concern. The performances where determined using portable ultrasonic flow meters, a Yates meter, precision manometers and appropriate electrical equipment for power measurement (Power Analiser - NORMA D4000 LEM). The measurements are not supposed to interfere with the normal operation so only a limited number of tests could be performed. Based on those tests, portions of the test curves have been measured and represented in specific diagrams.

Festas populares e turismo cultural - inserir e valorizar ou es-quecer? O caso dos Moçambiques de Osório, Rio Grande do Sul

Directory of Open Access Journals (Sweden)

Ribeiro, Marcelo

2004-01-01

Full Text Available This article analises the relations between popular culture, whith religious theme and cultural tourism. The structure of Moçambiques afrobrasilian group, in the Rio Grande do Sul State, southern Brazil and his celebration like a cultural tourism resource. The formulation of cultural policies nearest to touristic policies and one shape of a new preservation and knowledge

Sentir o “Paraíso” no Pantanal: reflexões sobre percepção e valoração ambientais

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Icléia A. de Vargas

2003-01-01

Full Text Available This paper analises the construction of the mith around the environment and the landscape of Pantanal. The mith is perceived as paradise’s model to be enjoyed for tourism activities. In this perspective, it unveils the mith of “Pantanal-Paradise” like the contradiction that emerges through expansion of tourism’s activities oriented for the market’s logical.

Mark Antony’s Homoeroticism in Cicero’s second Philippic

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Bruna Fernanda Abreu

2017-06-01

Full Text Available Considering the concept of homosexuality in the ancient Rome, we attempt to analise how Cicero expose the Mark Antony’s “homosexuality” in his second Philippic. This speech is characterized by political and, mainly, personal accusations from Cicero to Mark Antony, and the Mark Antony’s passivity in his intercourses can be considered a topos of this invective speech.

Nanofluid heat transfer under mixed convection flow in a tube for solar thermal energy applications.

Science.gov (United States)

Sekhar, Y Raja; Sharma, K V; Kamal, Subhash

2016-05-01

The solar flat plate collector operating under different convective modes has low efficiency for energy conversion. The energy absorbed by the working fluid in the collector system and its heat transfer characteristics vary with solar insolation and mass flow rate. The performance of the system is improved by reducing the losses from the collector. Various passive methods have been devised to aid energy absorption by the working fluid. Also, working fluids are modified using nanoparticles to improve the thermal properties of the fluid. In the present work, simulation and experimental studies are undertaken for pipe flow at constant heat flux boundary condition in the mixed convection mode. The working fluid at low Reynolds number in the mixed laminar flow range is undertaken with water in thermosyphon mode for different inclination angles of the tube. Local and average coefficients are determined experimentally and compared with theoretical values for water-based Al2O3 nanofluids. The results show an enhancement in heat transfer in the experimental range with Rayleigh number at higher inclinations of the collector tube for water and nanofluids.

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.

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.

Analisis Kinerja Keuangan Pemerintah Provinsi Jambi dan Pengaruhnya terhadap Pertumbuhan Ekonomi

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Mohar Mondes

2017-04-01

Full Text Available The purpose of this research is to analise government’s financial performance of Jambi Province. This research is using multiple linear regression to calculate and to see the effect of direct and indirect expenditure variable to the economic growth. This research is using secondary data that includes of local revenues, equalization funds, financial reception area, direct and indirect expenditure and also total expenditure of Jambi Province. This research is using verifikatif and kuantitatif analysis which is suite for analise fiscal autonomy degree, fiscal dependency of Jambi Province toward central government and also to find out whether the direct and indirect expenditure has effect to economic growth. Research results showed that Jambi Province’s DOF based on local revenue is 39,57%, placed in average condition, however if local revenue is add on DBH, it showed that the criteria is very good with 58,92%. The level of fiscal dependency 34,80% in average for years during observasion periode. By using multiple linear regression, the result showed that direct and indirect expenditure were positively and significantly effected to the economic growth of Jambi Province

Exploring the bio-psychosocial effects of renal replacement therapy amongst patients in a state hospital in South Africa

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Madhubala Kasiram

2011-05-01

Opsomming Hierdie artikel beskryf ‘n kwalitatiewe studie wat die bio-psigososiale effekte van niervervangingsterapie op pasiënte in ‘n staatshospitaal in Suid-Afrika ondersoek het. Die studie is gemotiveer deur die mate van debiliteit van pasiënte wat hemodialise (HD en kontinue ambulatoriese peritoneale dialise (KAPD ondergaan en wat oënskynlik verder strek as bloot die fisieke aspekte van die siekte en die behandeling daarvan. Respondente het bestaan uit ‘n klein groep HD- en KAPD-pasiënte. Deur ‘n onderhoudskedule as die navorsingsinstrument te gebruik, is ryk data onthul. Inhoudanalise en die redusering van data tot temas het die data-analise gefasiliteer. Alhoewel die studie nie kwantitatief was nie en vergelykende analise dus nie moontlik was nie, het temas van spanning onder die respondente voorgekom. Dit was duidelik uit die onderhoude met albei pasiëntgroepe en inhoudanalise dat die HD-groep meer bekommernis oor die graad van debiliteit en psigososiale stres getoon het as die KAPD-groep.Regeringsondersteuning vir holistiese nierbehandeling en versigtige samestelling van ‘n span sleutelrolspelers vir die vermindering van die erns en verreikende gevolge van HD en KAPD word voorgestel.

The lived experiences of late-adolescent female suicide survivors: ‘A part of me died’

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Willem A. Hoffmann

2010-06-01

Opsomming Mense se gedagtes fokus meestal op die selfmoordslagoffer onmiddellik na ’n voltooide selfmoord. Tog is die werklike slagoffers die persone wat agterbly om die lewe na die selfmoord te hanteer. Hierdie fenomenologies-sielkundige studie het die geleefde belewenisse van laat-adolessente oorlewendes ondersoek, spesifiek daardie negatiewe belewenisse wat skynbaar erger word in die weke en maande na ’n betekenisvolle ander se voltooide selfmoord. Die navorsingsdeelnemers was vyf vroulike laat-adolessente (17–22 jaar oud wat gewerf is deur middel van doelgerigte selektering by ’n Suid-Afrikaanse tersiêre instelling en jeugkampe. Data-insameling het geskied aan die hand van collage-gefasiliteerde, aangesig-tot-aangesig fenomenologiese onderhoude. Sommige deelnemers het addisionele dokumente in die vorm van persoonlike dagboeke, briewe en gedigte beskikbaar gestel vir data-analise. Die data is geanaliseer volgens Giorgi se fenomenologiese metode. Die volgende belewenisse het na vore getree tydens die data-analise: skuldgevoelens, self-blaam/spyt, blameer ander/God, woede, verlies/inperking van ‘self’, depressie, sub-optimale gedragshanteringspatrone, veranderinge in verhoudingsdinamika, en selfmoordneigings. Die resultate van hierdie studie kan deur geestesgesondheidwerkers en versorgers aangewend word om adolessente selfmoordagtergeblewenes effektief te ondersteun in die rouproses.

TRANSFORMATION OF MOTORICAL ABILITIES CHILDREN STRATURE FROM 10 TO 12 YEARS

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Branimir Mikić

2011-03-01

Full Text Available because of solving some specifical tasks which areappeared in all phases of game. Player must be able, that on max. level distinguish his motorical abilities (speed, explosive power, coordination….If we want quality respond to request of game, the player must be motoricaly build up and condicionaly ready, that we can achieve with one sistematical way of planning and programming of training process. Conditional preparation of young groups need to be very good structured process of evolved and maintenance conditional abilities with contents, methods, and strain which will stimulate dynamic progress football players , with all development of sensibile phases for progrsss comditional abilities( Bompa,T.,2005. In this exoloration, it was target to establish how much and how application trenage technology affect on progess of motorical abilities football players (children strature from 10 to 12 years, which training small football.For analise and processing informations applicate is :T-test with target to establish quantitative changes in motorical space , like as factory analise with target to establish qualitative changes in structure of motorical space of explorated pattern with influence of training technology characteristical for small football.

Feelings of women accompanying children hospitalized in a Paediatric Intensive Care Unit

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Cassiana Mendes Bertoncello Fontes

2017-03-01

Full Text Available Objective: Analise feelings of women accompanying children in a paediatric intensive care unit Materials and Methods: Data were collected from August to October 2015 by the authors from individual interviews recorded with 15 women. The instrument was structured with the identification of qualitative variables, described in absolute and relative frequencies, and a guiding question. The "corpus" of each interview was electronically transcribed, floating readings were held and statements were categorized and analysed according Analise Content.  Results: 14 (93% are biological mothers; average age 30 years; 11 (73% have completed primary education; six (46% have an occupation or a profession. The four themes were inferred: ambivalence of feelings and coping were related to how individuals express and deal with the hospitalized patient’s situation; empathy with the health team and the structural condition of the critical environment can also generate feelings. Nursing diagnoses were formulated from the reported feelings. Conclusion: It was observed that the feelings identified could be originated by the health-illness hospitalization process as well as the structural components of the critical environment. Keywords: Paediatric Intensive Care Units; Women; Feelings.

Total mercury concentrations in surface water and sediments from Danube Delta lakes

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TEODOROF Liliana

2007-10-01

Full Text Available The samples were collected from surface water and sediments of Danube Delta lakes, during april and may 2006. The sediments were digested with nitric acid, and the surface water with real aqua, at Microwave Oven Anton Paar and analised at FIMS 400 Perkin Elmer. The results show that the total mercury is compared with the maximum allowed limits according with Normative 161/2006.

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.

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)

Retoriek, retoriese analise en prediking

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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.

Studies of decay heat removal by natural convection using the SONACO sodium-cooled 37-pin bundle

International Nuclear Information System (INIS)

Wydler, P.; Dury, T.V.; Hudina, M.; Weissenfluh, T. von; Sigg, B.; Dutton, P.

1986-01-01

Natural convection measurements in an electrically heated sodium-cooled rod bundle are being performed with the aim of contributing to a better understanding of natural convection effects in subassemblies with stagnant sodium and providing data for code validation. Measurements include temperature distributions in the bundle for different cooling configurations which simulate heat transfer to the intersubassembly gap and neighbouring subassemblies and possible thermosyphonic interaction between a subassembly and the reactor plenum above. Conditions for which stable natural convection patterns exist are identified, and results are compared with predictions of different computer codes of the porous-medium type. (author)

Critical heat flux of water in vertical tubes with an upper plenum and a closed bottom

International Nuclear Information System (INIS)

Kim, Hong Chae; Baek, Won Pil; Chang, Soon Heung

2000-01-01

An experimental study is conducted for vertical round tubes with an upper plenum and a closed bottom to investigate CHF behavior and CHF onset location under the counter-current condition. The measured CHF values are well predicted by general Wallis type flooding correlations. A 1-D steady state analytical flooding model for thermosyphon by El-Genk and Saber was assessed with the data and the liquid film thickness at the liquid entrance was calculated. The CHF onset position becomes different with L/D and D, and liquid entrance geometry affects only CHF values not CHF onset positions

Skeptic Spirituality or the Accidental Buddhism of Machado de Assis's O Segredo do Bonzo

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Dilip Loundo

2014-09-01

Full Text Available The objective of the present article is to support the idea that Machado de Assis’ work conforms well to what may be called a non-religious spirituality. For that, the article’s main focus is the analysis of the short story “O Segredo do Bonzo: Capítulo Inédito de Fernão Mendes Pinto”, published in 1882’s collection titled Papéis Avulsos, where the main principles of that spirituality, which is spread all over his work,  are given in a nutshell. In a first moment, we analise the intertextuality between Machado’s short story “O Segredo do Bonzo” and Portuguese Renaissance writer’s travelogue Peregrinação and the Machado’s nineteen century critique of the west’s main universalizing proposals: Christianity, scientificity and Enlightenment. In a second moment, we analise the philosophical implications of the primacy given to ‘opinion’ as an existential foundation and as a constitutive element of reality, in a context of close proximity with the soteriological traditions of ancient Greek skepticism, on the one hand, and Buddhism, on the other. A critic of religion, specially of Christian religion, Machado’s  ‘accidental’ association with Buddhism is symptomatic of a very peculiar form of non-religious spirituality.

Radioactive elements definition in composition of snake venom

International Nuclear Information System (INIS)

Mekhrabova, M.A.; Topchieva, Sh.F.; Abiev, G.A.; Nagiev, Dj.A.

2010-11-01

Full text: The given article presents questions concerned to usage of snake venom in medicine and pharmacy for medicinal drugs production, zootoxin base antidotes, thorough treatment of many deseases, especially onkological, also have a widespread in biology as a specific test-material for biological sistem analises. It is experimentally proved that certain amount of snake venom can replace morphine drugs, taking into acount that snake venom solutions make longer prolonged influence than other drugs, vithout causing an accustoming. It is also marked about possibility of usage of snake venom for cancer treatment. Many expeditions had been conducted with the purpose to research snake venom crytals on the territory of Azerbaijan. During these expeditions snakes capturing had been made with the purpose of taking the venom and also soil samples had been taken in order to research the quantity of radioactive elements. Measurements made with the help of electronic microscope C anberra . Revealed uranium activity in spectrum of venom as a result of radiation background, which appears under influence of ionizing radiation on the environment. On the base of analises data it can be ascertained that snake venom can be used for production of medicinal and also other necessary drugs. [ru

GEOMETRIC COMPLEXITY ANALYSIS IN AN INTEGRATIVE TECHNOLOGY EVALUATION MODEL (ITEM FOR SELECTIVE LASER MELTING (SLM#

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S. Merkt

2012-01-01

Full Text Available

ENGLISH ABSTRACT: Selective laser melting (SLM is becoming an economically viable choice for manufacturing complex serial parts. This paper focuses on a geometric complexity analysis as part of the integrative technology evaluation model (ITEM presented here. In contrast to conventional evaluation methodologies, the ITEM considers interactions between product and process innovations generated by SLM. The evaluation of manufacturing processes that compete with SLM is the main goal of ITEM. The paper includes a complexity analysis of a test part from Festo AG. The paper closes with a discussion of how the expanded design freedom of SLM can be used to improve company operations, and how the complexity analysis presented here can be seen as a starting point for feature-based complexity analysis..

AFRIKAANSE OPSOMMING: Selektiewe lasersmelting word geleidelik ’n gangbare ekonomiese keuse vir die vervaar-diging van opeenvolgende komplekse onderdele. Die navorsing is toegespits op die ontleding van meetkundige kompleksiteit as ’n gedeelte van ’n integrerende tegnologiese evalueringsmodel. Gemeet teen konvensionele evalueringsmodelle behandel die genoemde metode interaksies tussen produkte- en prosesinnovasies wat gegenereer word. Die navorsing behandel ’n kompleksiteitsontleding van ’n toetsonderdeel van die firma FESTO AG. Die resultaat toon hoe kompleksiteits-analise gebruik kan word as die vertrekpunt vir eienskapsgebaseerde analise.

Heat Rejection from a Variable Conductance Heat Pipe Radiator Panel

Science.gov (United States)

Jaworske, D. A.; Gibson, M. A.; Hervol, D. S.

2012-01-01

A titanium-water heat pipe radiator having an innovative proprietary evaporator configuration was evaluated in a large vacuum chamber equipped with liquid nitrogen cooled cold walls. The radiator was manufactured by Advanced Cooling Technologies, Inc. (ACT), Lancaster, PA, and delivered as part of a Small Business Innovative Research effort. The radiator panel consisted of five titanium-water heat pipes operating as thermosyphons, sandwiched between two polymer matrix composite face sheets. The five variable conductance heat pipes were purposely charged with a small amount of non-condensable gas to control heat flow through the condenser. Heat rejection was evaluated over a wide range of inlet water temperature and flow conditions, and heat rejection was calculated in real-time utilizing a data acquisition system programmed with the Stefan-Boltzmann equation. Thermography through an infra-red transparent window identified heat flow across the panel. Under nominal operation, a maximum heat rejection value of over 2200 Watts was identified. The thermal vacuum evaluation of heat rejection provided critical information on understanding the radiator s performance, and in steady state and transient scenarios provided useful information for validating current thermal models in support of the Fission Power Systems Project.

On Responsibility of Scientists

Science.gov (United States)

Burdyuzha, Vladimir

The situation of modern world is analised. It is impossible for our Civilization when at least half of the World Scientists are engaged in research intended to solve military problems. Civilization cannot be called reasonable so long as it spends a huge portion of national incomes on armaments. For resolution of our global problems International Scientific Center - Brain Trust of planet must be created, the status of which should be defined and sealed by the UN organization.

Auctioning emission permits in a leader-follower setting

OpenAIRE

Alvarez, Francisco; André, Francisco J.

2015-01-01

We analise emission permit auctions under leader-follower competition when the leader bids strategically and the follower acts as price-taker both at the auction and the secondary market. We obtain linear equilibrium bidding strategies for both firms and a unique equilibrium of the auction, which is optimal ex-post for the leader. Under specific distributional assumptions we conclude that the auction always awards less permits to the leader than the cost-effective amount. Our central result i...

Arqueología del Paisaje: de la reflexión a la planificación

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Almudena Orejas

2018-01-01

Full Text Available The recent apparition of a good number of projects and publications about ancient territories and landcapes constitutes a motiv of thougt on the direction this line of reseach is taking. The is not only a need to evaluate the theoretical and methodological dcvelopment, the place that applied tecniques are playing, but also to analise its conexion with the so much debated «survey archaelogy» and the new approachcs to the concept of historical heritage.

Análisis estadístico de los registros de ruido electroquímico obtenidos en la corrosión del aluminio

OpenAIRE

Sánchez, A.; Sanjurjo, M.; Bouzada, F.; Urréjola, S.

2005-01-01

Given that the experimental signals obtained in an electrochemical noise measurement, ENM, are recorded over a discrete time period, the most direct way of analising them will be in the time domain resorting to statistical methods. These can be classified into two groups according to use: those which attempt to quantify the degree of the corrosion process (standard deviations, statistical power); and those which attempt to provide information on the corrosion mechanism (based on the assumptio...

About the correlation between atomic charge fluctuations in a molecule

International Nuclear Information System (INIS)

Pitanga, P.; Giambiagi, M.S. de; Giambiagi, M.

1987-01-01

In this note, the features of the correlation between the electronic charge fluctuations of a pair of atoms within a molecule are analised. Through Schwarz's inequality for random operators in the Hilbert space, the softness of an atom in a molecule is related to its valence and to the softness of the other atoms. It is concluded that in the general case this correlation (from which in turn stems the chemical bond) in non-linear. (author) [pt

Pressões (sócio)linguísticas na determinação do acento enfático: análise de alguns fenômenos variáveis

OpenAIRE

Carlos Alexandre Gonçalves

2017-01-01

Analise do fenômeno da ênfase prosódica, tomando como base seu efeito em fenômenos de variação/mudança linguística. Descrição da ênfase como grupo de fator relevante em pesquisas labovianas sobre processo de assimilação -ndo/-no. os fenômenos de aférese e prótese em processos de intensificação da língua.

Development of a heat exchanger for the cold side of a thermoelectric module

Energy Technology Data Exchange (ETDEWEB)

Vian, J.G.; Astrain, D. [Department of Mechanical Engineering, Universidad Publica de Navarra, UPNA, 31006 Pamplona (Spain)

2008-08-15

A heat exchanger for the cold side of Peltier pellets in thermoelectric refrigeration, based on the principle of a thermosyphon with phase change and capillary action has been developed. This device improves the thermal resistance between the cold side of a Peltier pellet and the refrigerated ambient by 37% (from 0.513 of the finned heat sink, to 0.323 K/W). Analytic calculations and experimental optimisation of the TPM have been carried out by building and testing several prototypes. It also has been experimentally proved that the COP of thermoelectric refrigerators can be improved up to 32% (from 0.297 to 0.393) by incorporating the developed device. (author)

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

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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

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)

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)

Comportamento do Consumidor Esportivo no Ambiente Virtual: Um Estudo das Ações e Práticas de Mercado Brasileiro, Espanhol e Português.

Directory of Open Access Journals (Sweden)

Raquel Rodrigues de Amorim

2015-01-01

Full Text Available Neste estudo buscou-se primeiramente descobrir como a rede social está sendo utilizada pelas empresas esportivas como uma ferramenta de marketing digital e quais as principais características do marketing digital na busca ou estreitamento da comunicação entre os clubes de futebol e seus consumidores. Para isso foi dividida em quatro partes esta pesquisa; sendo a primeira uma ampliação do referencial teórico em que buscamos compreender mais sobre todas as questões a serem pesquisadas. Em uma segunda parte fizemos um estudo a partir dos websites dos clubes de futebol integrantes da amostra para uma avaliação e analise das possíveis falhas ou melhorias a serem questionadas pelos consumidores. Em seguida foi realizada a coleta dos dados a partir de questionários digitais apresentados a torcedores e/ou simpatizantes dos clubes predefinidos para a amostra e por último foi feito a análise dos dados através do programa estatístico SPSS, resultando na obtenção dos resultados através dos testes de Alpha de Crombach, Levene e Tukey. A partir das analises e resultado obtido chegou-se a uma conclusão do uso do meio virtual na busca de uma melhor percepção da satisfação dos consumidores esportivos.

Alcance y sentido de la cultura pedagógica bajomedieval

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Javier VERGARA CIORDIA

2010-03-01

Full Text Available RESUMEN: Este trabajo analiza el alcance y sentido de la pedagogía en la Baja Edad Media, a partir de tres pilares que contribuyeron sobremanera a conformar su personalidad pedagógica y cultural: la educación intelectual, moral y religiosa, la apuesta por una emergente secularización y la visión positiva de las artes mecánicas. Ejes que, al discurrir por una apuesta más secular, racional y humanista de la cultura, dieron lugar, por un lado, a la aparición de uno de los momentos más sugerentes y atractivos del acontecer cultural del Occidente cristiano y, por otro, a lo que puede considerarse la base y antesala de la eclosión humanista y científica de los siglos XIV a XVI. ABSTRACT: This work analises the scope and sense of the pedagogy in the Middle Ages (XII- XIII centuries. It analises three very important pillars: the intellectual, moral and religious education, the bet for an initial secular culture and a new vision of the mechanical arts. These axes had a secular, rational and humanist character of the culture. They originated the appearance of one of the most attractive periods in the West culture and provides with the humanist, rational and scientific base of the XIV centuries to XVI.

[The premises of a policy of early childhood during the second empire: The association for the care of lying-in women].

Science.gov (United States)

Vitoux, M C

1995-01-01

As early as the 1830's, the social elite of Mulhouse was aware of the higher infant mortality in the working class. A family policy was adopted only during the Second Empire: the consciousness of the failure of the first philanthropic measures explains why the manufacturers decided to take direct responsibility for the working class family. The demographic preoccupations are directly linked to philanthropy. This paper analises the principles and evaluates the results of the Association for the care of lying-in women.

Homogalactanas sulfatadas da macroalga verde Codium isthmocladum: aspectos estruturais e farmacológicos

OpenAIRE

Farias, Eduardo Henrique Cunha de [UNIFESP

2011-01-01

Galactanas e o termo utilizado para designar polissacarideos que contem galactose. Homogalactanas sulfatadas, SG 1 e SG 2, foram extraidas de macroalga marinha verde Codium isthmocladum apos proteolise, fracionamento por acetona a frio e cromatografia de troca-ionica. A massa molecular foi determinada por cromatografia de gel-filtracao em HPLC e deteccao por indice de refracao e UV, sendo que SG 1 apresenta massa molecular media ao redor de 12 kDa e SG 2 de 15,0 kDa. Analises estruturais empr...

Recovery tread wheel pairs of machining

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Igor IVANOV

2013-01-01

Full Text Available The basic methods of resurfacing wheels are determined and analised. It’sshown that for raising resource of used wheels and decreasing requirements of railwaytransport for new wheels it’s reasonable to use methods of recovering not only geometricparameters of rim, but also its mechanical properties. It’s marked that use of infeedprofile high-speed grinding (VPVSh enables to intensify significantly process ofmechanical treatment of wheel rim profile both when its resurfacing in service and whenmanufacturing new wheel.

Relativistic nuclear reactions and the intranuclear cascade method

International Nuclear Information System (INIS)

Duarte, S.J.B.

1983-01-01

The intranuclear cascade (INC) procedure is analised as a method to describe the processes of relativistic heavy ions collisions. The effects caused by nucleon concentration during the collision are discussed. It is shown explicitly that the occurence of nonbinary collisions among particles is not at all negligible, in spite of the fact that the convencional INC only permits nucleon-nucleon binary collisions. The relativistic invariance of the results obtained by the INC method is discussed. This is especially important when the method is applied for much higher energies. Many of conventional procedures in the method will give certainly different predictions depending on what system of reference is used. The origin of such non-invariance nature of INC calculations is discussed and an alternative way of defining the INC procedure which presents a better credibility with respect to the relativistic invariance property is proposed. (Author) [pt

Contribution to the study of the thermal and hydrodynamical properties of a two-phase natural circulation flow of normal helium (He I) for the cooling of superconducting magnets; Contribution a l'etude des proprietes thermiques et hydrodynamiques d'un ecoulement d'helium normal (He I) diphasique en circulation naturelle pour le refroidissement des aimants supraconducteurs

Energy Technology Data Exchange (ETDEWEB)

Benkheira, L

2007-06-15

The method of cooling based on the thermosyphon principle is of great interest because of its simplicity, its passivity and its low cost. It is adopted to cool down to 4,5 K the superconducting magnet of the CMS particles detector of the Large Hadron Collider (LHC) experiment under construction at CERN, Geneva. This work studies heat and mass transfer characteristics of two phase He I in a natural circulation loop. The experimental set-up consists of a thermosyphon single branch loop mainly composed of a phase separator, a downward tube, and a test section. The experiments were conducted with varying several parameters such as the diameter of the test section (10 mm or 14 mm) and the applied heat flux up to the appearance of the boiling crisis. These experiments have permitted to determine the laws of evolution of the various parameters characterizing the flow (circulation mass flow rate, vapour mass flow rate, vapour quality, friction coefficient, two phase heat transfer coefficient and the critical heat flux) as a function of the applied heat flux. On the base of the obtained results, we discuss the validity of the various existing models in the literature. We show that the homogeneous model is the best model to predict the hydrodynamical properties of this type of flow in the vapour quality range 0{<=}x{<=}30%. Moreover, we propose two models for the prediction of the two phase heat transfer coefficient and the density of the critical heat flux. The first one considers that the effects of the forced convection and nucleate boiling act simultaneously and contribute to heat transfer. The second one correlates the measured critical heat flux density with the ratio altitude to diameter. (author)

Contribution to the study of the thermal and hydrodynamical properties of a two-phase natural circulation flow of normal helium (He I) for the cooling of superconducting magnets

International Nuclear Information System (INIS)

Benkheira, L.

2007-06-01

The method of cooling based on the thermosyphon principle is of great interest because of its simplicity, its passivity and its low cost. It is adopted to cool down to 4,5 K the superconducting magnet of the CMS particles detector of the Large Hadron Collider (LHC) experiment under construction at CERN, Geneva. This work studies heat and mass transfer characteristics of two phase He I in a natural circulation loop. The experimental set-up consists of a thermosyphon single branch loop mainly composed of a phase separator, a downward tube, and a test section. The experiments were conducted with varying several parameters such as the diameter of the test section (10 mm or 14 mm) and the applied heat flux up to the appearance of the boiling crisis. These experiments have permitted to determine the laws of evolution of the various parameters characterizing the flow (circulation mass flow rate, vapour mass flow rate, vapour quality, friction coefficient, two phase heat transfer coefficient and the critical heat flux) as a function of the applied heat flux. On the base of the obtained results, we discuss the validity of the various existing models in the literature. We show that the homogeneous model is the best model to predict the hydrodynamical properties of this type of flow in the vapour quality range 0≤x≤30%. Moreover, we propose two models for the prediction of the two phase heat transfer coefficient and the density of the critical heat flux. The first one considers that the effects of the forced convection and nucleate boiling act simultaneously and contribute to heat transfer. The second one correlates the measured critical heat flux density with the ratio altitude to diameter. (author)

Incubadoras de empresas

OpenAIRE

Baldissera, Idovino

2000-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico. O objeto de analise do presente são as incubadoras de empresas da região do Alto e Médio Vale do Rio do Peixe, nos aspectos que se referem à constituição e desenvolvimento delas, enquanto empreendimentos geradores de empresas, ressaltando seus aspectos funcionais, referentes aos programas de assessoria, treinamento, assistência técnica e acompanhamento aos proprietários de empresas incubadas e verifica...

GOEMORFOLOGIA FLUVIAL DA BACIA HIDROGRÁFICA DO RIO DE ONDAS

Directory of Open Access Journals (Sweden)

Ossifleres Silva Damasceno

2011-10-01

Full Text Available Os estudos de Geomorfologia Fluvial para analise de Bacias Hidrográficas vêm tendo nos últimos tempos grande importância, tanto para se conhecer as características de determinadas bacias como para se planejar o uso de tais recursos. Neste sentido, este trabalho foi efetuado no intuito de somar aos estudos anteriormente executados nessa bacia, levantando algumas características geomorfológicas, o uso e ocupação atual. Palavras-chaves: geomorfologia fluvial, hidrografia, agricultura irrigada.

Reflexões sobre a prática do aleitamento materno Reflexions about breastfeeding's practices

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Isilia Aparecida Silva

1996-04-01

Full Text Available O trabalho traz uma análise sobre o aleitamento materno, fazendo reflexões sobre os indicadores determinantes da situação atual, buscando identificar os elementos fins e meios para atingir o cenário idealizado para o futuro da prática do amamentar.The autor makes analises of breast feeding, doing a reflexion about the mainly indicators who has determined the atual situation, looking for identify ways for win the ideal cenary to future of breast feeding.

Solar receiver with integrated optics

Science.gov (United States)

Jiang, Lun; Winston, Roland

2012-10-01

The current challenge for PV/Thermal (PV/T) systems is the reduction of radiation heat loss. Compared to solar thermal selective coating, the solar cells cannot be used as an efficient thermal absorber due to their large emissivity of the encapsulation material. Many commercial PV/T products therefore require a high concentration (more than 10x) to reach an acceptable thermal efficiency for their receivers. Such a concentration system inevitably has to track or semi-track, which induces additional cost and collects only the direct radiation from the sun. We propose a new PV/T design using a vacuum encapsulated thin film cell to solve this problem. The proposed design also collects the diffuse sun light efficiently by using an external compound parabolic concentrator (XCPC). Since the transparent electrode (TCO) of thin film cell is inherently transparent in visible light and reflective beyond infrared, this design uses this layer instead of the conventional solar cell encapsulation as the outmost heat loss surface. By integrating such a vacuum design with a tube shaped absorber, we reduce the complexity of conducting the heat energy and electricity out of the device. A low concentration standalone non-tracking solar collector is proposed in this paper. We also analyzed the thermosyphon system configuration using heat transfer and ray tracing models. The economics of such a receiver are presented.

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)

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...

Einstein equation solutions with axial symmetry, conical and essential singularities

International Nuclear Information System (INIS)

Oliveira, S.R. de.

1986-01-01

New classes of exact solutions to the Einstein equations of a static axisymetric space-time associated with rings and disks are found. Also, the solutions associated to a axisymetric superposition of punctual bodies, bars, rings and disks are obtained. These solutions have a strut singularities to keep the bodies apart. When one of the bodies of the superposition is a ring, the ring interior is covered with a membrane that serve as a support for the strut that hold the other body. Furthermore, the curvature singularities for different solutions ae analised. (author) [pt

Conexões florísticas e funcionamento de comunidades arbóreas associadas à inselberg no domínio atlântico

OpenAIRE

Paula, Eduardo de Paiva

2014-01-01

A presente dissertação encontra-se estruturada em dois artigos. No primeiro, objetivou-se, compreender as relações fitogeográficas de três comunidades arbóreas associadas a um inselberg,em Minas Gerais (Serra da Canoa), através da análise florística de 22 localidades/unidades florestais , em diferentes escalas geográficas do mesmo Estado, incluindo três comunidades arbóreas associadas a outro inselberg, em MG. Foram utilizadas duas técnicas de analise multivariada: Análise de correspondência ...

An introduction to the analysis of multi-cavity prestressed concrete pressure vessels

International Nuclear Information System (INIS)

Silva, M.C.A.T. da.

1986-01-01

The present work is a study of multi-cavity prestressed concrete pressure vessels (PCRV) for nuclear reactors. A review is made of the designs, analises and models of multi-cavity concrete pressure vessels. A preliminary evaluation of the NONSAP program for applications in complex three-dimensional structures such as a multi-cavity pressure vessel is also made. A model of a PCRV of a 1000 MW(e) high-temperature gas cooled reactor was selected for a three-dimensional analysis with the NONSAP program. The results obtained are compared with experimental data. (Author) [pt

A relevância dos indicadores de margem de contribuição na gestão de produtos diferenciados em um supermercado

OpenAIRE

Roehrs, Leonardo dos Santos

2014-01-01

Esse trabalho tem como objetivo fazer uma analise dos indicadores de margem de contribuição no desempenho e rentabilidade de uma gama de produtos de uma seção denominada “Gastronomia Especial” criada a partir da dificuldade encontrada por um grupo de pessoas em encontrar produtos diferenciados para cursos de culinária e até a para gastrônoma do dia-a-dia. Com a acirrada concorrência no comércio varejista e as exigências de alguns consumidores, o aumento do mix de produtos e a c...

Estudo QSPR sobre os coeficientes de partição: descritores mecânico-quânticos e análise multivariada QSPR study on partition coefficients: quantum-mechanical descriptors and multivariate analysis

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Edilson Grünheidt Borges

2002-12-01

Full Text Available Quantum chemistry and multivariate analysis were used to estimate the partition coefficients between n-octanol and water for a serie of 188 compounds, with the values of the q 2 until 0.86 for crossvalidation test. The quantum-mechanical descriptors are obtained with ab initio calculation, using the solvation effects of the Polarizable Continuum Method. Two different Hartree-Fock bases were used, and two different ways for simulating solvent cavity formation. The results for each of the cases were analised, and each methodology proposed is indicated for particular case.

Guias ópticos para sensores

OpenAIRE

Marcos de Castro Pacitti

1993-01-01

Neste trabalho foram estudados guias ópticos para atuarem como sensores ou em sistemas sensores. Ênfase especial foi dada em guias ópticos retangulares, para dispositivos ópticos integrados, e fibras ópticas elípticas. A analise de fibras ópticas elípticas resultou em um modelamento pratico para projeto das mesmas em aplicações onde se deseja operar com dois modos guiados, situação esta que se mostra muito atraente para implementação de diversos tipos de sensores a fibra óptica. A seguir es...

Produção de fermentado alcoólico de laranja

OpenAIRE

Oliveira, Janine Patricia Melo; Neto, José Crisóstomo da Silva; Silva, Saulo Soares da; Santos, Adriana da Silva

2015-01-01

Este trabalho tem como objetivo produzir um fermentado alcoólico proveniente do suco de laranja (Citrus sinensis), segundo processo adaptado das metodologias já existentes para obtenção de outros fermentados de fruta. O processo produtivo do fermentado de laranja e as analises referentes ao mesmo foram conduzidos no Laboratório de Operações Unitárias e Fenômeno de Transporte do Centro de Ciências e Tecnologia Agroalimentar da Universidade de Campina Grande – Campus Pombal - Pb. Com relação às...

A phenomenological approach to angular momentum transfer in deep inelastic heavy ion collisions

International Nuclear Information System (INIS)

Barbosa, V.C.; Soares, P.C.; Oliveira, Edgar C. de; Gomes, Luiz Carlos

1985-01-01

The total angular momentum transfer measured in the reactions 165 Ho on 176 Yb, 154 Sm and sup(Nat)Ag at 1400 MeV and 86 Kr + 152 Sm 610 MeV were analised on the basis of a classical model with friction forces including, besides the relative motion of the ions, their rotations and quadrupole vibrations. The ratios of tangential or pivotal to radial friction were fixed by the analysis and found to be 1/20. No strong evidences of the sticking mechanisms were found. (Author) [pt

The unique requirements of primary health care in Southern Africa

Directory of Open Access Journals (Sweden)

D. P. Knobel

1986-03-01

Full Text Available The critical need for primary health care in Southern Africa with special reference to the demands of the heterogenous population is measured against the background of the declaration of Alma Ata at the WHO/UNICEF conference in 1978. In particular the provision of primary health care to the Third World communities of the RSA as an essential part of the security power base of the State is underlined and it is analised in terms of how shortcomings in this service can be exploited in a subversive revolutionary onslaught.

A obsolescência programada e psicológica como forma de biopoder: perspectivas jurídicas do consumismo / Planned and psychological obsolescence as a form of biopower: law perspectives of consumerism

OpenAIRE

Andrade, Sinara Lacerda; Universidade de Marília - UNIMAR; Santiago, Mariana Ribeiro; Universidade de Marília - UNIMAR

2016-01-01

DOI: 10.12957/rqi.2016.21252Trabalho enviado em 01 de fevereiro de 2016. Aceito em 02 de maio de 2016.Resumo:O presente trabalho tem o escopo de enquadrar a obsolescência programada e psicológica como mecanismo de biopoder, demonstrando que tais práticas exercem determinado controle sob o consumidor, retirando-lhe, por vezes, a capacidade cognitiva de decidir o que, quando e se necessário consumir. O referencial teórico para analise das práticas abusivas foi a sociedade de consumo. Evidencian...

Produção sustentável e controlada de ostras

OpenAIRE

Jacomel, Bruno

2014-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-graduação em Engenharia de Produção, Florianópolis, 2014 Santa Catarina posiciona-se atualmente como o segundo maior polo produtor de moluscos bivalves da América Latina. Além disso, o estado é responsável por 95% da produção nacional de moluscos bivalves. Dada a crescente importância conquistada pelo setor, este trabalho tem o objetivo de realizar uma analise comparativa entre os resultado...

"From The Worst To The Best": An Exploratory Qualitative Study Of The Process Of Social Change At A South African Secondary School

Directory of Open Access Journals (Sweden)

Berendien Van Aswegen

2003-11-01

Die primêre doel van die studie is die beskrywing van ’n organisatoriese verandering by ’n voorheen benadeelde skool in Suid-Afrika se Gauteng Provinsie. Kwalitatiewe metodes is gebruik om data oor die sosiale proses te genereer en te analiseer. Opstelle van betrokkenes by die veranderingsproses oor hulle ervarings het tot belangrike insigte gelei. Hierdie verkennende studie dui op ’n proses wat suksesvol gewerk het om verandering te weeg te bring en hou belofte in vir die ontwikkeling van ’n teoretiese model van hoe verandering in oneffektiewe skole bewerkstellig kan word.

A substituição do conceito pelo sujeito: genealogia nietzscheana versus dialética socrática

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Ana Carolina da Costa e Fonseca

2006-12-01

Full Text Available The article discusses Nietzsche’s description and criticism of the socratic dialetical method, as well as Nietzsche’s method of investigation – the genealogy. Nietzsche considers the human being a creator of concepts and methods of investigation. The methods of investigation are associated with human types and its way of relationship to the efective reality. The genealogy analises the will to power that produces the concepts and consider it as symptom of one human types. Nietzsche criticizes the Socratic dialectical method, specially, because it is created by a decadent human type.

"Ônibus 174": O sujeito e sua representação filmica.

OpenAIRE

Julia Gonçalves Declie Fagioli

2010-01-01

Através da analise do filme Ônibus 174 (Brasil, 2002) de José Padilha, pretende-se, neste trabalho, esclarecer fenômenos da comunicação no cinema documentário. Para isso, será preciso compreender o modelo relacional de Comunicaç...

Pumpless geothermal heat probe - Phase 1: investigation of potential and energetic and commercial feasibility; Pumpenlose Erdwaermesonde Phase 1: Potentialabklaerung, Machbarkeitsstudie energetisch und wirtschaftlich

Energy Technology Data Exchange (ETDEWEB)

Peterlunger, A.; Ehrbar, M. [Interstaatliche Hochschule fuer Technik Buchs, Labor fuer Thermodynamik und Kaeltetechnik, Buchs (Switzerland); Bassetti, S.; Rohner, E. [Geowatt AG, Zuerich (Switzerland)

2004-07-01

This final report for the Swiss Federal Office of Energy (SFOE) discusses the results of an investigation made at the University of Applied Science in Buchs, Switzerland, on the subject of thermosyphon-based geothermal heat probes. These probes are considered as being a further development of traditional, brine-filled vertical geothermal probes and possess the advantage of not needing a pump to circulate the heat-transfer medium. The resulting improvement in the Coefficient of Performance (COP) of such heat-pump systems is quoted as being 12 to 15%. The question of appropriate probe design - probe-diameters of 40 mm and lengths of 350 m are considered to be optimal - is discussed and compared with actual installations that have already been made in Switzerland. As far as heat transfer media are concerned, the advantages and disadvantages of ammonium and carbon dioxide are discussed. Also, the need for inexpensive ways of repairing possible leaks in these high-pressure systems is discussed. The report also looks at the possibilities of using such probes for cooling applications. The physics of the heat-transfer process is explained and the results of numerical modelling of the ground-loops are presented. Comparisons are made between the energy-efficiency and costs of such systems and conventional heat-pump systems using vertical and horizontal heat exchangers as well as those using ground-water as a source of heat. The report is concluded with a forward look at the second phase of the project.

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

Applied Hts Bulks and Wires to Rotating Machines for Marine Propulsion

Science.gov (United States)

Miki, M.; Felder, B.; Kimura, Y.; Tsuzuki, K.; Taguchi, R.; Shiliang, Y.; Xu, Y.; Ida, T.; Izumi, M.

2010-04-01

High-temperature superconductors allow a compact and efficient way to provide high-torque density to rotating machines with excellent operation. A field pole, providing flux density of more than 1.5 T around the armature, was initially designed for an axial-gap type with the flux parallel to the rotor axis. Melt-growth Gd-123 bulks as well as Bi-2223 wire windings have been successfully assembled on the rotor disk. No iron core was used, though being an auxiliary flux control found in most HTS motors. Both bulk and wire types have realized a practical motor operation within a limited output range. For bulks, a 15 kW, 720 rpm, synchronous motor was designed and tested in the group of TUMSAT, Kitano Seiki and University of Fukui. A bulk field pole was cooled down by liquid nitrogen and was magnetized in the motor. To enhance the output power to more than 30 kW, we developed a thermosyphon system using condensed neon. Another field pole with HTS wire for large-scale marine propulsion is also discussed on a 100 kW, 230 rpm tested machine. A closed-cycle condensed neon associated with thermal insulation is also reported.

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)

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)

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.

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.

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)

Guided reflection as a tool to deal with the theory– practice gap in critical care nursing students

Directory of Open Access Journals (Sweden)

Hester Cathrina de Swardt

2012-04-01

Opsomming Kritiekesorgverpleegstudente ervaar teenstrydighede ten opsigte van dit wat hul geleer word en wat van hul in die praktyk verwag word wat weer die leerproses vertraag. Dit word as die teorie–praktykgaping beskryf. Daar blyk geen enkelvoudige oplossing te wees vir die integrasie van teorie en praktyk nie. In ’n poging om die gaping te oorbrug, is ’n studie oor die invloed van begeleide refleksie op kritiekesorgverpleegkundige studente se teoretiese en praktiese ervaringe gedoen. ’n Kwalitatiewe, verkennende, beskrywende en kontekstuele navorsingsontwerp is gevolg. ‘n Instrument vir begeleide refleksie is ontwerp wat gebruik is tydens semi-gestruktureerde onderhoude in die data-insamelingsproses. Veldnotas en narratiewe beskrywings was ook middele ten einde data in te samel. Tema’s wat uit die data na vore gekom het was ‘n beskrywing van ervaringe, kritiese analise van data, kritiese analise van gevoelens en ‘n veranderde perspektief met betrekking tot ervaringe. Teorie–praktyk integrasie het tot ‘n mate in sommige kategorieë plaasgevind het. Daarinteen het die onvermoë om die teorie in die praktyk toe te pas response tot gevolg gehad, soos skuldgevoelens en gevoelens van onbevoegdheid. Dit wil voorkom asof begeleide refleksie die deelnemers gehelp het om duidelikheid en ’n veranderde perspektief ten opsigte van hul teoretiese en praktiese ervaringe te verkry. Begeleide refleksie behoort reeds vanaf basiese opleiding in verpleegkundiges se teoretiese en praktiese opleiding geïnkorporeer te word sodat verpleegkundiges bewus sal wees van hulle eie vaardighede om sodoende optimale pasiëntsorg te kan lewer.

Heat Pipe-Assisted Thermoelectric Power Generation Technology for Waste Heat Recovery

Science.gov (United States)

Jang, Ju-Chan; Chi, Ri-Guang; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Lee, Wook-Hyun

2015-06-01

Currently, large amounts of thermal energy dissipated from automobiles are emitted through hot exhaust pipes. This has resulted in the need for a new efficient recycling method to recover energy from waste hot exhaust gas. The present experimental study investigated how to improve the power output of a thermoelectric generator (TEG) system assisted by a wickless loop heat pipe (loop thermosyphon) under the limited space of the exhaust gas pipeline. The present study shows a novel loop-type heat pipe-assisted TEG concept to be applied to hybrid vehicles. The operating temperature of a TEG's hot side surface should be as high as possible to maximize the Seebeck effect. The present study shows a novel TEG concept of transferring heat from the source to the sink. This technology can transfer waste heat to any local place with a loop-type heat pipe. The present TEG system with a heat pipe can transfer heat and generate an electromotive force power of around 1.3 V in the case of 170°C hot exhaust gas. Two thermoelectric modules (TEMs) for a conductive block model and four Bi2Te3 TEMs with a heat pipe-assisted model were installed in the condenser section. Heat flows to the condenser section from the evaporator section connected to the exhaust pipe. This novel TEG system with a heat pipe can be placed in any location on an automobile.

Gender, Environment and the Theory of Complexity

Directory of Open Access Journals (Sweden)

Regina Célia Di Ciommo

2003-01-01

Full Text Available We use the theory of complexity to analise gender questions, showing that those are built by society in an exchange of interactions between nature and culture. The bioanthropological rootsand and the sociocultural characteristics contain different experiences, knowledge and wisdom, in a complex organization in which oposition does notmean extinction, and difference does not imply hierarchy. We can apply Morin’s “tetralogical ring” concept, which admits disorder, organization, order and interaction to the understanding of the impasse between masculine and feminine, humans and non-humans, towards a paradigmatic change in the social and environmental relations.

O comportamento alimentar de escolares do ensino básico e sua associação com excesso de peso e consumo da alimentação escolar

OpenAIRE

Juliana Melo Teruel Biagi Camargo

2015-01-01

Resumo: A mudança no padrão de consumo de alimentos e o sedentarismo têm levado ao aumento do excesso de peso da população em todo mundo. Nos países em desenvolvimento, a prevalência do excesso de peso tem aumentado rapidamente, principalmente entre as crianças. No Brasil, as analises das Pesquisas de Orçamentos Familiares (POF) tem evidenciado a tendência do aumento do excesso de peso na infância e da diminuição da desnutrição. A obesidade é acompanhada de comorbidades consideradas problemas...

Credibility and music´s effect as therapeutic kind in health

Directory of Open Access Journals (Sweden)

Karyne Cristine da Fonseca

2006-12-01

Full Text Available This article has as purpose to analise the professional´s music therapist´s perception about the credibility and approval of music therapy by their clients. It´s a qualitative research, developed in Goiânia-GO, between 2003, august and 2004, june. We verified that the professional´s majority noted their client´s credibility related to music capacity in transmitting pleasant sensations and its capacity to act in a efficient way on the healing process of some diseases. They too evidence that the music therapy needs to be published with more effectiveness for the population.

Transversabilidade, Bioética e Complexidade: Considerações acerca de uma Metabioética

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Antonio Basilio Novaes Thomaz de Menezes

2010-10-01

Full Text Available A ideia central deste texto é de discutir as condições de compreensáo da bioetica, a partir da hipotese de um quadro referendal que residiria no proprio entendimento do conceito. Assim, o texto inicia por uma analise da compreensáo do conceito, para depois apontar para um quadro referendal derivado do mesmo, e, finalmente, apresentar a ideia de uma metabioetica, enquanto uma perspectiva de compreensáo da bioetica que pode ser estruturada a partir do principio da complexidade, aplicado as Ciencias Humanas (Morin, e fundamentado na concepçáo do pensamento transversal (Deleuze/Guattari.

A Modernidade em Foucault: uma breve Exposição

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Guilherme Castelo Branco

2010-10-01

Full Text Available o artigo trata da compreensáo da Modernidade no pensamento de Foucault abordando a dimensáo historica da atualidade na esfera de problematizaçáo socio-politica dos nossos dias. Seu nucleo de argumentacáo concentra-se nas condições de exame da questáo etica atraves da leitura que Foucault faz de Kant do principio da maioridade , do telos da afiio e da autonomia individual. Com isto o artigo propõe um eixo de analise da ideia foucaultiana de uma estetica da existencia a partir da relaçao entre subjetividade e poder.

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

Heat transfer characteristics and operation limit of pressurized hybrid heat pipe for small modular reactors

International Nuclear Information System (INIS)

Kim, Kyung Mo; Bang, In Cheol

2017-01-01

Highlights: • Thermal performances and operation limits of hybrid heat pipe were experimentally studied. • Models for predicting the operation limit of the hybrid heat pipe was developed. • Non-condensable gas affected heat transfer characteristics of the hybrid heat pipe. - Abstract: In this paper, a hybrid heat pipe is proposed for use in advanced nuclear power plants as a passive heat transfer device. The hybrid heat pipe combines the functions of a heat pipe and a control rod to simultaneously remove the decay heat generated from the core and shutdown the reactor under accident conditions. Thus, the hybrid heat pipe contains a neutron absorber in the evaporator section, which corresponds to the core of the reactor pressure vessel. The presence of the neutron absorber material leads to differences in the heated diameter and hydraulic diameter of the heat pipe. The cross-sectional areas of the vapor paths through the evaporator, adiabatic, and condenser sections are also different. The hybrid heat pipe must operate in a high-temperature, high-pressure environment to remove the decay heat. In other words, the operating pressure must be higher than those of the commercially available thermosyphons. Hence, the thermal performances, including operation limit of the hybrid heat pipe, were experimentally studied in the operating pressure range of 0.2–20 bar. The operating pressure of the hybrid heat pipe was controlled by charging the non-condensable gas which is unused method to achieve the high saturation pressure in conventional thermosyphons. The effect of operating pressure on evaporation heat transfer was negligible, while condensation heat transfer was affected by the amount of non-condensable gas in the test section. The operation limit of the hybrid heat pipe increased with the operating pressure. Maximum heat removal capacity of the hybrid heat pipe was up to 6 kW which is meaningful value as a passive decay heat removal device in the nuclear power

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)

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)

Ondersoek na ’n teoretiese onderskraging van boekkuns: Die toepassing van Bakhtin se dialogisme en heteroglossia op geselekteerde voorbeelde van kunstenaarsboeke

Directory of Open Access Journals (Sweden)

David Paton

2012-11-01

Full Text Available Onlangse navorsingsprojekte en konferensies oor boekkuns het gereageer op Johanna Drucker se oproep in 2005 dat noodsaaklike navorsingswerk gedoen moet word om ’n deegliker teoretiese basis vir die terrein van boekkunsproduksie te vestig. Die deelname van kunstenaars en ander praktisyns van boekkuns veroorsaak dat gesprekke en besprekings noodwendig en voorspelbaar neig na die praktyk en weg van die teorie. In die lig van die behoefte aan die bepaling van ’n toepaslike visie waarvolgens die kunsboek meer eksplisiet, ook teoreties, ondersoek kan word, ondersoek hierdie artikel Stéphane Mallarmé en Marcel Broodthaers se Un coup de dés publikasies, Buzz Spector se simplifiserende Marcel Broodthaers, Ulises Carrion se For fans and scholars alike, en Helen Douglas en Telfer Stokes se Real fiction. Hierdie spesifieke voorbeelde, en hulle onderlinge verbande en dialoog met mekaar, word ondersoek vanuit die perspektief van die Russiese filosoof en literêre teoretikus Mikhail Bakhtin se werk oor dialogisme en heteroglossia (‘ander-tongigheid’. Hierdie begrippe demonstreer die dialogiese, multivokale en veeltongige wisselwerking tussen en binne historiese werke as kultuuruitings. Deur die analise toon ek aan dat hierde begrippe toepaslike en funksionele raamwerke uitmaak vir die analise van spesifieke aspekte wat die teenwoordigheid van kunstenaarsboeke aankondig in die wêreld: selfbewustheid en omvattende diskoers wat wederkerend toepaslik is. Ek stel voor dat Bakthin se idees oor dialogisme en heteroglossie gebruik word as die teoretiese begronding van die kunstenaarsboek as ’n dinamiese visuele taal wat in ’n netwerk van ander tekste staan en deel is van die proses van die eindelose herbeskrywing van die wêreld.

Considerações acerca do processo de constituição e institucionalização do curso de licenciatura em Ciências Sociais na EAD/UAB - Unimontes

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Claudia Regina Santos de Almeida

2013-02-01

Full Text Available A Educação a distância não pode ser entendida apenas pelo aspecto de uso das tecnologias no processo de ensino, mas antes como uma prática educativa mediatizada e de democratização do conhecimento. Sua essência envolve a construção de conhecimento mediada, valendo-se das tecnologias como meio e espaço da relação de ensino e aprendizagem. Objetivo: O artigo tem como objetivo apresentar as especificidades e aspectos gerais do processo de constituição e institucionalização da Licenciatura em Ciências Sociais na Educação a Distância. Entendendo que o projeto de Universidade Aberta do Brasil envolve a produção interativa de conhecimento baseado na difusão das tecnologias da informação e na configuração da inteligência coletiva no ciberespaço. Meto dologia: Utilizou-se para tanto, de pesquisa bibliográfica e analise documental para entender e construir o desenho estrutural do curso de Licenciatura em Ciências Sociais. Resultados: O processo de constituição e institucionalização do Curso de Licenciatura em Ciências Sociais na UAB/Unimontes, derivou de constantes debates sobre a demanda de professores de sociologia e a necessidade de formação adequada. Considerações finais: Este trabalho representa uma síntese dos processos avaliativos como também da analise documental dos produtos gerados pelo curso em qualidade de educação e formação.

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)

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.

REAPROVEITAMENTO D’ÁGUA DA ESTAÇÃO DE TRATAMENTO DE EFLUENTES: EMPRESA INTELBRAS – SÃO JOSÉ (SC)

OpenAIRE

Schulz, Clair Teresinha; Henkes, Jairo Afonso

2013-01-01

Este trabalho tem por objetivo mostrar conceitos teóricos e técnicas aplicadas ao reuso de água em vasos sanitários e como essa prática pode contribuir na busca da sustentabilidade dos recursos hídricos. No seu desenvolvimento são abordadas as possibilidades do reuso e suas principais aplicações, os tratamentos requeridos para a aplicação do reuso e as atuais discussões sobre os requisitos de qualidade da água para essa aplicação. O estudo de caso consiste em analise técnica para a implantaçã...

Quando um primitivo é como um orbe? Quando um primitivo é como um orbe?

Directory of Open Access Journals (Sweden)

J. Hillis Miller

2008-04-01

Full Text Available Minhas estratégias de analise textual se tornarão mais ou menos evidentes na leitura que se segue. Sua proveniência deveriam tornar-se & cia. 0 ensaio foi inicialmente pensado come parte do livro The Linguistic Moment (Princeton: Princeton University Press, 1985. Aqui, como no livro, minha preocupação maior e com aqueles momentos em poemas em que a poesia como meio de comunicação constitui problema. Interessa-me particularmente a forma pela qual as fronteiras entre a linguagem conceitual e a figurative se tornam pouco visiveis no poema "A Primitive like an Orb", da última fase da poesia de Wallace Stevens.

Crisis management with applicability on fire fighting plants

Science.gov (United States)

Panaitescu, M.; Panaitescu, F. V.; Voicu, I.; Dumitrescu, L. G.

2017-08-01

The paper presents a case study for a crisis management analysis which address to fire fighting plants. The procedures include the steps of FTA (Failure tree analysis). The purpose of the present paper is to describe this crisis management plan with tools of FTA. The crisis management procedures have applicability on anticipated and emergency situations and help to describe and planning a worst-case scenario plan. For this issue must calculate the probabilities in different situations for fire fighting plants. In the conclusions of paper is analised the block diagram with components of fire fighting plant and are presented the solutions for each possible risk situations.

The contribution of the European Union to global climate change governance: explaining the conditions for EU actorness

Directory of Open Access Journals (Sweden)

Carolina B. Pavese

2012-01-01

Full Text Available Como organização regional, o papel da União Europeia na governança global do clima enfrenta obstáculos que não se aplicam a nenhuma outra parte da Convenção-Quadro das Nações Unidas sobre a Mudança do Clima (CQNUMC e do Protocolo de Quioto. Avaliando essa singularidade, este artigo fornece uma analise teórica e empírica de como os elementos de actorness (reconhecimento, capacidade, oportunidade e coesão definem a participação da UE no regime internacional de mudanças climáticas.

Production and mechanical properties of sintered carbides (hard steels WC-Co)

International Nuclear Information System (INIS)

Batalha, G.F.

1987-09-01

Densification and mechanical characteristics or WC-Co Cemented Carbides, were investigated by dilatometry, Hardness and bending tests, as a function of the two principal micro-structural parameters: the cobalt content and the particle size of carbide crystals. Vickers hardness of the studied compositions showed a linear variation with the increase of the cobalt content. By three point bending, the transverse rupture strenght increases with cobalt content, however, for larger grain size reaches a maximum, eventually reduced by brittle phases and incomplete dispersion. The results of brittle facture tests were statistically analised and fitted better to the 'Weakest Link Model' (Weibull distribution) than the 'Chain Model' (Gaussian distribution). (author) [pt

Order, disorder and chaos in crystal lattice

International Nuclear Information System (INIS)

Oliveira, M.J. de; Salinas, S.R.A.

1985-01-01

The properties of two two-dimensional mappings corresponding to the solutions of spin models on a Cayley tree in infinite coordination limit are analised in detail. The models under consideration are related to some mechanisms which were proposed to explain the occurrence of modulated phases in magnetic crystals. The existence of devil's staircases characterized by fractal dimensionalities which increase with temperature is shown. Numerical evidences to support the existence of a strange attractor, of a fractal character, in the Ising model with competing interactions restricted to the branches of a Cayley tree are presented. The route to chaos agrees with the scenario of Feigenbaum. (Author) [pt

A “crítica ‘Mafaldiana’ ” à sociedade burguesa numa leitura marxista: HQ’s e contra-hegemonia na aula de história

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Carlos Eduardo Rebuá Oliveira

2010-12-01

Full Text Available Starting with a critical reading of Mafalda, written by Quino, the argentinean comics writer, and based on Gramsci‟s hegemony concept, we are trying to analise the possibilities of collecting ideas against hegemony within the teaching of History, through which we call “„Mafaldian‟ criticism” to the charactheristic elements of the burgess society. Gramsci contributions to education (The dialetic relation between hegemony and education and his discussion about private means of hegemony and the war of position, are fundamental pillars of the analisys. In metodological terms, we have selected six cartoons of Mafalda, chosen from Toda Mafalda, with the purpose of reinforcing the reflections herein.

O vestuário no cinema: percursos de análise em filmes portugueses de etnoficção

OpenAIRE

Cucinotta, Caterina

2016-01-01

A presente tese enfrenta o tema do documentário e da ficção no cinema de etnoficção português pondo ao centro deste binómio o vestuário como fenómeno, ora votado a explicitar a verosimilhança das sequencias, ora ferramenta para criar uma simulação da realidade. Tratamos o termo etnoficção como se fosse um género cinematográfico e escolhemos, como exemplo de analise, 3 trilogias do cinema português. Tratamos o vestuário de acordo com os novos conceitos do corpo revestido que vee...

Desenho infantil na escola: a significação do mundo por crianças de quatro e cinco anos

OpenAIRE

Adriana Torres Maximo Monteiro

2013-01-01

No contexto da educação infantil, a presente pesquisa teve como objetivo buscar referenciais advindos da Psicologia Histórico-cultural e da Sociologia da Infância para a compreensão e análise do desenho infantil, para além do olhar etapista. Tais referenciais orientaram na captura, descrição e analise do que acontece com as crianças e seus desenhos, quando desenham juntos na escola. A análise microgenética permitiu delimitar um estudo de caso que destaca a voz e a participação das crianças de...

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)

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)

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.

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)

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)

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)

Esqueletogênese em punaré (Thrichomys laurentinus- Rodentia, Echimyidae

Directory of Open Access Journals (Sweden)

Phelipe O. Favaron

Full Text Available Resumo: O objetivo deste estudo foi descrever o desenvolvimento do esqueleto do punaré (Thrichomys laurentinus. Para tanto, foram utilizados 11 embriões e 12 fetos em diferentes estágios de desenvolvimento, sendo divididos em 4 grupos de acordo com o período gestacional. As amostras foram obtidas no Centro de Multiplicação de Animais Silvestres da Universidade Federal Rural do Semi-Árido, Mossoró-RN, Brasil. Após fixados em formol (10% ou glutaraldeído (2,5%, foi realizada a analise morfológica com auxílio de lupa, sendo as características macroscópicas fotodocumentadas. Análises de raios-x e coloração por alizarina red foram realizadas para melhor compreensão do desenvolvimento ósseo. Nas análises de raio-x os embriões não apresentaram nenhuma radiopacidade, ao contrário dos fetos que apresentavam radiopacidade gradual ao longo dos grupos. No grupo II houve aumento de radiopacidade na região da coluna vertebral e das regiões mandibular e maxilar. No grupo III a radiopacidade estava aumentada nos membros pélvicos, nas costelas e na região frontal e no grupo IV nos membros torácicos e nas regiões occipital, temporal e frontal do crânio. Tais características foram confirmadas pelas analises histológicas e pela técnica de Alizarina Red. Com isso podemos concluir que o conhecimento acerca da embriologia do sistema ósseo normal é fundamental para o entendimento dos efeitos adversos causados pela nutrição e uso de drogas durante o desenvolvimento.

Caracterização de sedimento proveniente de dragagem de canais pluviais do município de Salvador-BA visando sua utilização em cerâmica estrutural

Directory of Open Access Journals (Sweden)

O. C. Santos

Full Text Available Resumo Este trabalho teve como objetivo caracterizar o sedimento proveniente de dragagem de canais pluviais (SCP, do município de Salvador-BA, visando sua máxima substituição pela argila em cerâmica estrutural, uma vez que essa mistura binária faz parte do projeto piloto da massa padrão, na pesquisa da formulação de blocos intertravados cerâmicos. Inicialmente o sedimento foi submetido aos ensaios de índice de plasticidade, analise química por fluorescência de raios X, análise mineralógica por difração de raios X, analise térmica e granulométrica. A morfologia do material foi analisada utilizando-se microscopia eletrônica de varredura, acompanhada de espectroscopia de energia dispersiva. Em seguida foram feitas adições de sedimento (SCP a uma argila do município de Candeias-BA, nas proporções de 10, 20, 30 e 40% em massa. Foram preparados corpos de prova por prensagem uniaxial nas dimensões 60 mm x 20 mm, com pressão de compactação de 25 MPa, sendo que o material foi umidificado com 8% de água. A queima foi realizada em forno resistivo a 850, 950 e 1050 °C, com taxa de aquecimento de 5 °C/min. As propriedades avaliadas foram retração linear, absorção de água e módulo de ruptura à flexão. Os resultados indicaram que é possível a utilização do SCP em cerâmica estrutural, mediante os pré-requisitos exigidos em normas, na fabricação de telhas, blocos de vedação e tijolos.

The role of graphite foam pore structure on saturated pool boiling enhancement

International Nuclear Information System (INIS)

Pranoto, I.; Leong, K.C.; Jin, L.W.

2012-01-01

This paper presents an experimental study of the pool boiling phenomena and performance of porous graphite foam evaporators of different structures and thermophysical properties. Two dielectric liquids viz. FC-72 and HFE-7000 were used as working fluids. Block and fin evaporators of different fin-to-block-surface-area ratios (AR) were designed to study the role of the internal pore structure of graphite foams in a compact air-cooled thermosyphon under saturated pool boiling condition for high heat flux electronics cooling applications. The wall temperatures were measured and the boiling heat transfer coefficients were calculated to analyze the boiling performance. It was found that both fin structures with AR = 3.70 and 2.73 result in reduced boiling heat transfer performances and higher wall temperatures. The experimental results show that the boiling heat transfer coefficients of the block structures are about 1.2–1.6 times higher than those of the fin structures. The total internal surface area to volume ratio (β) and the total exposed areas (A T ) of the graphite foams were calculated in this study. The results show that the values of β and A T of the block structures are much higher than the fin structures for both tested “Pocofoam” 61% porosity and “Kfoam” 78% porosity evaporators which resulted in higher boiling heat transfer coefficient and lower wall temperature of the block structures. A visualization study shows that more bubbles were generated from the block structures compared to the fin structures due to the larger number of nucleation sites from the block structures. It was also found that use of FC-72 resulted in better boiling heat transfer performance compared to HFE-7000. - Highlights: ► We studied the pool boiling performance of a thermosyphon with graphite foam evaporators of block and fin structures. ► FC-72 and HFE-7000 were used as the working fluids. ► The boiling heat transfer coefficients of the block structures are 1.2�

Bevordering van transformerende leer: Die skryf van ’n reflektiewe joernaal in die Natuurwetenskappe

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Erna R. du Toit

2012-03-01

Full Text Available Die doel van die artikel is om aan te toon hoe die skryf van ’n reflektiewe joernaal in die Natuurwetenskappe die perspektiewe en denke van onderwysstudente kan transformeer en/of leer kan bevorder. Die studie maak voorspraak vir die gebruik van ’n reflektiewe joernaal as ’n instrument vir studente om betekenis te gee aan die leeromgewing vanuit verskillende perspektiewe deur te leer in praktyk. ’n Kwalitatiewe navorsingsmetode is gevolg om die inskrywings in ’n joernaal te analiseer aan die hand van bepaalde indikatore. Die bevindinge toon dat die meeste studente na die praktykervaring positief was en sommiges het tot ander perspektiewe vanweë hul ervaring gekom.

FINANCING MECHANISMS OF AGRICULTURE IN ROMANIA

Directory of Open Access Journals (Sweden)

BUMBESCU SORINA SIMONA

2015-03-01

Full Text Available The objective of this article is to highlight the importance of the agriculture financing ways, existing an interdependence relationship between the stage of agriculture development and its funding mechanisms. This article presents in a complex way, the general theoretical framework of the agriculture financing, and the practical methods of agriculture finance from bank loans to European programs and projects, the impact of EU funds on agriculture. The research leads to two important categories of tangible results; on one hand it highlights the most important and used ways to finance the Romanian agriculture, and on the other hand, there is analised the impact of EU funds on rural development, their absorption.

Use of 14 MeV neutrons in analysis of explosive class materials

International Nuclear Information System (INIS)

Dighe, P.M.; Pansare, G.R.; Bhoraskar, V.N.

1992-01-01

Samples of explosive class materials were analised by 14 MeV neutron activation technique to estimate concentrations of oxygen, nitrogen, aluminium and chlorine. For aluminized explosives, test of stability against temperature was carried out by heating samples at 75 deg C and loss of nitrogen was studied by measuring the ratio of aluminium to nitrogen in the sample. Loss of oxygen and nitrogen in a triple base propellant heated at 71.6 deg C, was also estimated by measuring residual oxygen and nitrogen in a heated sample. This technique is convenient to adopt in the laboratory and useful to decide quickly the suitability of explosive class materials for practical applications. (author) 8 refs.; 2 figs.; 1 tab

A conquista de Marte e a expansão da análise geográfica (Notas para um debate

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Francisco MENDONÇA

1997-12-01

Full Text Available O homem originou-se no Nordeste da África e expandiu-se por todo o planeta nestes últimos 2.500.000 anos. A descrição das características do espaço terrestre tem sido registrada desde os Gregos, porém a Geografia somente tornou-se um conhecimento cientifico no século XIX. A conquista do espaço expandiu-se para além dos limites do planeta e atingiu Marte, porém a descrição das novas áreas tem sido feitas conforme os princípios "geo''gráficos. Neste contexto questiona-se: deveria a analise geográfica manter-se presa à Geo?

Apocalypse Now: elements of the Literary Journalism in thecinematographic construction by Vietnan War

Directory of Open Access Journals (Sweden)

Gisele Krodel Rech

2015-06-01

Full Text Available One of the most revered films of war, Apocalypse Now presentes fragments of journalistic representation of reality within a narrative film. They are analogies of the book Dispatches, by Michael Herr, book from the New Journalism phenomenon, which served to support the contextualization of Coppola’s masterpiece process. The intention of this paper is therefore analise the film seeking to find in these analogies textual elements of ekphrasis and fanopeia. In this process, in which the literary journalism narrative is enmeshed in film narrative, non fiction and representation of reality arises intermittently through the fictional work, in a process fraught with imagetic connotative meanings, designed from the power of text of literary journalism.

Separation of sup(99m)Tc from 99Mo through a hydrous zirconium oxide column

International Nuclear Information System (INIS)

Mengatti, J.

1980-01-01

The preparation of 99 Mo-,sup(99m)Tc generator based on the adsorption of 99 Mo on hydrous zirconium oxide column, employing the in exchange technique, is described. The adsorption of 99 Mo on hydrous zirconium oxide (HZO) and the separation of sup(99m)Tc, generated by the decay of 99 Mo with saline solution, are analised. The sup(99m)Tc separation yield, pH of the eluted solution, aspect of the elution curve and the adsorption of 99 Mo on hydrous zirconium oxide calcined at 800 0 C are studied. The chemical and radioactive purities of the final product are analysed and the variation of the elution yield for successive elutions is studied. (Author) [pt

The development of a curved beam element model applied to finite elements method

International Nuclear Information System (INIS)

Bento Filho, A.

1980-01-01

A procedure for the evaluation of the stiffness matrix for a thick curved beam element is developed, by means of the minimum potential energy principle, applied to finite elements. The displacement field is prescribed through polynomial expansions, and the interpolation model is determined by comparison of results obtained by the use of a sample of different expansions. As a limiting case of the curved beam, three cases of straight beams, with different dimensional ratios are analised, employing the approach proposed. Finally, an interpolation model is proposed and applied to a curved beam with great curvature. Desplacements and internal stresses are determined and the results are compared with those found in the literature. (Author) [pt

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)

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)

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)

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.

Experiments on heat pipes submitted to strong accelerations; Experimentation de caloducs soumis a de fortes accelerations

Energy Technology Data Exchange (ETDEWEB)

Labuthe, A [Dassault Aviation, 92 - Saint Cloud (France)

1997-12-31

In order to evaluate the possibility to use heat pipes as efficient heat transfer devices in aircrafts, a study of their behaviour during strong accelerations is necessary. This study has been jointly carried out by the Laboratory of Thermal Studies of Poitiers (France) and Dassault Aviation company. It is based on a series of tests performed with an experimental apparatus that uses the centrifugal effect to simulate the acceleration fields submitted to the heat pipe. Un-priming - priming cycles have been performed under different power and acceleration levels and at various functioning temperatures in order to explore the behaviour of heat pipes: rate of un-priming and re-priming, functioning in blocked mode etc.. This preliminary study demonstrates the rapid re-priming of the tested heat pipes when submitted to favourable acceleration situations and the possibility to use them under thermosyphon conditions despite the brief unfavourable acceleration periods encountered. (J.S.)

Acid fractionation for low level liquid waste cleanup and recycle

International Nuclear Information System (INIS)

Gombert, D. II; McIntyre, C.V.; Mizia, R.E.; Schindler, R.E.

1990-01-01

At the Idaho Chemical Processing Plant, low level liquid wastes containing small amounts of radionuclides are concentrated via a thermosyphon evaporator for calcination with high level waste, and the evaporator condensates are discharged with other plant wastewater to a percolation pond. Although all existing discharge guidelines are currently met, work has been done to reduce all waste water discharges to an absolute minimum. In this regard, a 15-tray acid fractionation column will be used to distill the mildly acidic evaporator condensates into concentrated nitric acid for recycle in the plant. The innocuous overheads from the fractionator having a pH greater than 2, are superheated and HEPA filtered for atmospheric discharge. Nonvolatile radionuclides are below detection limits. Recycle of the acid not only displaces fresh reagent, but reduces nitrate burden to the environment, and completely eliminates routine discharge of low level liquid wastes to the environment

Experiments on heat pipes submitted to strong accelerations; Experimentation de caloducs soumis a de fortes accelerations

Energy Technology Data Exchange (ETDEWEB)

Labuthe, A. [Dassault Aviation, 92 - Saint Cloud (France)

1996-12-31

In order to evaluate the possibility to use heat pipes as efficient heat transfer devices in aircrafts, a study of their behaviour during strong accelerations is necessary. This study has been jointly carried out by the Laboratory of Thermal Studies of Poitiers (France) and Dassault Aviation company. It is based on a series of tests performed with an experimental apparatus that uses the centrifugal effect to simulate the acceleration fields submitted to the heat pipe. Un-priming - priming cycles have been performed under different power and acceleration levels and at various functioning temperatures in order to explore the behaviour of heat pipes: rate of un-priming and re-priming, functioning in blocked mode etc.. This preliminary study demonstrates the rapid re-priming of the tested heat pipes when submitted to favourable acceleration situations and the possibility to use them under thermosyphon conditions despite the brief unfavourable acceleration periods encountered. (J.S.)

Hybrid Heat Pipes for Lunar and Martian Surface and High Heat Flux Space Applications

Science.gov (United States)

Ababneh, Mohammed T.; Tarau, Calin; Anderson, William G.; Farmer, Jeffery T.; Alvarez-Hernandez, Angel R.

2016-01-01

Novel hybrid wick heat pipes are developed to operate against gravity on planetary surfaces, operate in space carrying power over long distances and act as thermosyphons on the planetary surface for Lunar and Martian landers and rovers. These hybrid heat pipes will be capable of operating at the higher heat flux requirements expected in NASA's future spacecraft and on the next generation of polar rovers and equatorial landers. In addition, the sintered evaporator wicks mitigate the start-up problems in vertical gravity aided heat pipes because of large number of nucleation sites in wicks which will allow easy boiling initiation. ACT, NASA Marshall Space Flight Center, and NASA Johnson Space Center, are working together on the Advanced Passive Thermal experiment (APTx) to test and validate the operation of a hybrid wick VCHP with warm reservoir and HiK"TM" plates in microgravity environment on the ISS.

Thermal resistance of aluminum gravity heaГІ pipe with threaded capillary structure

Directory of Open Access Journals (Sweden)

Nikolaenko Yu. E.

2017-10-01

Full Text Available The results of an experimental study of the thermal resistance of an aluminum gravitational heat pipe with isobutane (R600a as a working fluid under conditions of heat removal of natural air convection are presented. Comparison of the thermal resistance of an aluminum gravitational heat pipe with a threaded capillary structure and the thermal resistance of an aluminum thermosyphon of the same size, having a smooth surface of the body in the evaporation zone, is given. It is shown that in the range of values of the input heat flux from 5 to 50 W the thermal resistance of the gravitational heat pipe is substantially lower than the thermal resistance of the thermosiphon. The studies were conducted both without the use of additional radiators in the condensation zone of heat transfer devices, and with the use of one, two and three radiators.

Reverse convection in helium and other fluids in the high speed rotating frame: negative and positive buoyancy effects

International Nuclear Information System (INIS)

Igra, R.; Scurlock, R.G.; Wu, Y.Y.

1986-01-01

Experimental studies of thermo-syphon flows in radial tubes and loops between the axis and the periphery of a rotating helium cryostat have shown that when heat is supplied at an intermediate radius, the heat is carried radially inwards as A flow and radially outwards as B flow. The results with helium suggest that while the steady state patterns of the A and B flows are complex, the heat is divided approximately equally between the conventional A flow and the reverse B flow. A model of convective heating in the rotating frame is presented and two necessary conditions for reverse convection are identified and discussed. The model predicts reverse convection in liquid nitrogen and this is confirmed by experimental measurement. An array of radial ducts is proposed for the cooling of a superconducting AC generator in order to counter the effects of reverse convection in the helium refrigerant

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)

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)

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)

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)

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)

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.

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

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)

Methods of bone marrow dose calculation

International Nuclear Information System (INIS)

Taboaco, R.C.

1982-02-01

Several methods of bone marrow dose calculation for photon irradiation were analised. After a critical analysis, the author proposes the adoption, by the Instituto de Radioprotecao e Dosimetria/CNEN, of Rosenstein's method for dose calculations in Radiodiagnostic examinations and Kramer's method in case of occupational irradiation. It was verified by Eckerman and Simpson that for monoenergetic gamma emitters uniformly distributed within the bone mineral of the skeleton the dose in the bone surface can be several times higher than dose in skeleton. In this way, is also proposed the Calculation of tissue-air ratios for bone surfaces in some irradiation geometries and photon energies to be included in the Rosenstein's method for organ dose calculation in Radiodiagnostic examinations. (Author) [pt

REPRESENTASI IDENTITAS SUNDA DALAM CERPEN ABAH JEUNG LAPTOP KARYA HIKMAT NUGRAHA

Directory of Open Access Journals (Sweden)

Maria Fiducia Nurullah

2017-02-01

Full Text Available This research described Sundanese identity on “Abah jeung Laptop” by Hikmat Nugraha. The research analised narrative struckture and setting on the short story. This study aimed to describe how the representasion of Sundanese identity on contemporary literature. This research used qualitative method and literature study for collecting the data. In analyzing the data, the researcher used narrative struckture method by Mieke Bal to describe how narrator and fokalisator on the short story affected how Sundanese identity be representasion on this story. The analysis showed the representasion of Sundanese identityon the actors on story changed because of modernize. The struggle which representing by the actors showed how shifting of identities was very difficult but identities always changed because of history and cultures change.

Factors Driving Changes To Remuneration Policy And Outcomes

Directory of Open Access Journals (Sweden)

Mark Bussin

2004-11-01

Die doel van hierdie studie is om die relatiewe belangrikheid van die faktore wat verandering in die vergoeding besluitnemingsbeleid dryf asook die impak wat dit op organisasie het in diepte te verstaan. Data van 148 organisasies is geanaliseer onderworpe aan streng statisiese analises. Die resultaat wys dat die mees kritieke drywers vir vergoedingsbeleid die volgende is: retensie van sleutelpersoneel, finansiële resultate en organisasie strategie. Die grootste veranderinge in vergoedsbeleid was in die volgende areas: veranderlike betaling, meriete/prestasie verwante betaling, markposisie, totale pakket en rolevaluasie/‘broadband’ beleid? Sterk korrelasie is gevind tussen die vlak van verandering in die vergoedingsbeleid en die impak op die organisasie. Dit wys onder andere uit hoe groter die verandering in vergoedingsbeleid, hoe groter die impak op die organisasie.

Experiences of being a therapy radiographer

Directory of Open Access Journals (Sweden)

Heather Lawrence

2011-11-01

Opsomming Die hoofdoel van hierdie navorsing is om te verken en beskryf hoe radioterapeute hulle beroep beleef. ‘n Kwalitatiewe, verkennende, beskrywende en kontekstuele navorsingsontwerp is gebruik. Die doelgerigte steekproef het bestaan uit 14 radioterapeute werksaam by ‘n akademiese hospitaal in Gauteng, Suid Afrika. Data is met behulp van fokusgroep onderhoude ingesamel totdat dataversadiging bereik is. ‘n ‘Appreciative inquiry’ onderhoudstegniek is gebruik met die stel van vrae, en data analise is met behulp van oop kodering gedoen om temas te identifiseer. Die temas wat geidentifiseer was is lewensgewende magte wat persoonlike en professionele betrokkenheid bevorder wat ‘n singewing tot gevolg het; professionele stagnering; en fasilitering van verandering deur die gebruikmaking van positiewe energie en toewyding vir verandering.

Representações sociais dos usuários hospitalizados sobre cidadania: implicações para o cuidado hospitalar

Directory of Open Access Journals (Sweden)

Flávia Pacheco de Araújo

2016-08-01

Full Text Available RESUMO Objetivo: analisar as representacoes sociais de usuarios hospitalizados sobre a cidadania no cuidado hospitalar. Método: abordagem qualitativa com referencial da Teoria das Representacoes Sociais, realizada com 31 usuarios hospitalizados no setor de clinica medica de um hospital publico, universitario. Realizou-se entrevista semiestruturada, cujos dados foram submetidos ao programa Alceste, com aplicacao de analise lexical. Resultados: os usuarios conhecem os seus direitos, e a cidadania no cuidado e entendida a luz dos direitos a saude, de modo que sejam bem atendidos do ponto de vista tecnico e humano. Conclusão: o bom trato relacional e a prestacao do cuidado tecnico-procedimental sao direitos dos usuarios; logo, a ausência de um ou de outra implica o nao respeito a sua cidadania.

Characterization and classification of patients with different levels of cardiac death risk by using Poincaré plot analysis.

Science.gov (United States)

Rodriguez, Javier; Voss, Andreas; Caminal, Pere; Bayes-Genis, Antoni; Giraldo, Beatriz F

2017-07-01

Cardiac death risk is still a big problem by an important part of the population, especially in elderly patients. In this study, we propose to characterize and analyze the cardiovascular and cardiorespiratory systems using the Poincaré plot. A total of 46 cardiomyopathy patients and 36 healthy subjets were analyzed. Left ventricular ejection fraction (LVEF) was used to stratify patients with low risk (LR: LVEF > 35%, 16 patients), and high risk (HR: LVEF ≤ 35%, 30 patients) of heart attack. RR, SBP and T Tot time series were extracted from the ECG, blood pressure and respiratory flow signals, respectively. Parameters that describe the scatterplott of Poincaré method, related to short- and long-term variabilities, acceleration and deceleration of the dynamic system, and the complex correlation index were extracted. The linear discriminant analysis (LDA) and the support vector machines (SVM) classification methods were used to analyze the results of the extracted parameters. The results showed that cardiac parameters were the best to discriminate between HR and LR groups, especially the complex correlation index (p = 0.009). Analising the interaction, the best result was obtained with the relation between the difference of the standard deviation of the cardiac and respiratory system (p = 0.003). When comparing HR vs LR groups, the best classification was obtained applying SVM method, using an ANOVA kernel, with an accuracy of 98.12%. An accuracy of 97.01% was obtained by comparing patients versus healthy, with a SVM classifier and Laplacian kernel. The morphology of Poincaré plot introduces parameters that allow the characterization of the cardiorespiratory system dynamics.

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)

Performance test of a 1 MW class HTS synchronous motor for industrial application

International Nuclear Information System (INIS)

Kwon, Y.K.; Kim, H.M.; Baik, S.K.; Lee, E.Y.; Lee, J.D.; Kim, Y.C.; Lee, S.H.; Hong, J.P.; Jo, Y.S.; Ryu, K.S.

2008-01-01

This paper deals with development activities of high temperature superconducting (HTS) synchronous motor at DOOSAN heavy industry and Korea Electrotechnology Research Institute (KERI) in Korea, and is sponsored by DAPAS program which is supported by Korean government. The final aim of the project is realization of HTS motor in the field of industry such as large driving pumps, fans and compressors for utility and industrial environments. At present time, 1 MW HTS motor is developed for the purpose to fully represent the design and manufacturing issues for the larger capacity machine. The number of pole and rotating speed of machine are 2 pole and 3600 rpm. The HTS field coil of the developed motor is cooled by way of neon thermosyphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes status of 1 MW HTS motor development, such as design, fabrication and performance test results, which was conducted at steady state in generator mode and motor mode

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)

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)

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)

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)

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.

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.

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)

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)

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)

Exército, Nação e Saúde: A medicina militar brasileira como elemento de criação de fronteira nacionais

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Tiago Penteado Bomfim

2017-12-01

Full Text Available Pretendemos a partir deste texto investigar e analisar, a atuação do médico e higienista do exército brasileiro Arthur Lobo da Silva, como produtor do conhecimento cientifico da área da saúde desta instituição, entre os anos de 1920 a 1940. Do mesmo modo, será preciso entender de que maneira a medicina militar se constituiu como um elemento criador de fronteira no início do século XX. A participação de Arthur Lobo da Silva nestes campos foi materializada em diversas publicações como jornais, periódicos, entre outros. Tais obras servirão de componente básico para analise deste trabalho. Destaca-se que as ideias do autor sobre higiene, saúde, e o papel do exército nos permitirão compreender a sua representação de nação, fronteira e região e o que este autor acredita ser o papel do Estado brasileiro no período. Ao expor tais opiniões e posicionamentos Arthur Lobo da Silva ira se inserir no debate com outros intelectuais brasileiros, a respeito dos problemas sanitários do país o que inviabilizava no período a criação de uma “nação”, “fronteira” e de um “povo brasileiro”, a inserção destes militares nesta discussão legitimou o papel do Exército como uma das soluções sociais para estes problemas. Para fazer tal analise, além de utilizar algumas publicações de Arthur Lobo da Silva, em periódicos militares e civis, os livros A luta contra as moléstias venéreas no Exército brasileiro (1929, O serviço de saúde do Exército brasileiro (1958, Antropologia no Exército brasileiro (1929, também serão utilizados para mapear a sua trajetória intelectual.

Fiber-optic components for optical communicatios and sensing =

Science.gov (United States)

Marques, Carlos Alberto Ferreira

Nos ultimos anos, a Optoelectronica tem sido estabelecida como um campo de investigacao capaz de conduzir a novas solucoes tecnologicas. As conquistas abundantes no campo da optica e lasers, bem como em comunicacoes opticas tem sido de grande importancia e desencadearam uma serie de inovacoes. Entre o grande numero de componentes opticos existentes, os componentes baseados em fibra optica sao principalmente relevantes devido a sua simplicidade e a elevada de transporte de dados da fibra optica. Neste trabalho foi focado um destes componentes opticos: as redes de difraccao em fibra optica, as quais tem propriedades opticas de processamento unicas. Esta classe de componentes opticos e extremamente atraente para o desenvolvimento de dispositivos de comunicacoes opticas e sensores. O trabalho comecou com uma analise teorica aplicada a redes em fibra e foram focados os metodos de fabricacao de redes em fibra mais utilizados. A inscricao de redes em fibra tambem foi abordado neste trabalho, onde um sistema de inscricao automatizada foi implementada para a fibra optica de silica, e os resultados experimentais mostraram uma boa aproximacao ao estudo de simulacao. Tambem foi desenvolvido um sistema de inscricao de redes de Bragg em fibra optica de plastico. Foi apresentado um estudo detalhado da modulacao acustico-optica em redes em fibra optica de silica e de plastico. Por meio de uma analise detalhada dos modos de excitacao mecanica aplicadas ao modulador acustico-optico, destacou-se que dois modos predominantes de excitacao acustica pode ser estabelecidos na fibra optica, dependendo da frequencia acustica aplicada. Atraves dessa caracterizacao, foi possivel desenvolver novas aplicacoes para comunicacoes opticas. Estudos e implementacao de diferentes dispositivos baseados em redes em fibra foram realizados, usando o efeito acustico-optico e o processo de regeneracao em fibra optica para varias aplicacoes tais como rapido multiplexador optico add-drop, atraso de grupo

Análise do ciclo de vida aplicada à produção de bioetanol a partir de material Lignocelulósico remanescente em dejeto bovino

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Amaro de Azevedo

2016-07-01

Full Text Available Biocombustíveis podem ter uma contribuição significativa na redução desses danos ambientais dependendo da sua rota de produção. A produção de bioetanol, ou etanol lignocelulósico, pode ser uma alternativa frente aos combustíveis fósseis e de grande relevância estratégica para o Brasil. Neste contexto, estudou-se a analise de ciclo de vida (ACV da produção de etanol a partir do material lignocelulósico contido no dejeto bovino. Estes dejetos são uma biomassa rica em celulose que pode ser convertida a glicose e outros açúcares fermentáveis e destes à bioetanol. Para tanto considerou-se como Unidade Funcional o processamento de 1.000 kg de dejeto. Para a analise dos impactos do método EcoIndicator 99, através das bibliotecas EcoInvent, do software SimaPro versão 7.3.2. Foram consideradas as seguintes categorias de impacto: cancerígenos, orgânicos e inorgânicos inaláveis, mudanças climáticas, radiação, camada de ozônio, ecotoxicidade, acidificação/eutrofização, uso do solo, minerais e combustíveis fósseis. Para avaliação de danos ambientais estas categorias foram agrupadas em três categorias de danos: danos à saúde humana, danos aos ecossistemas e danos aos recursos naturais. De acordo com o estudo realizado verificou-se que o insumo do processo que mais contribuiu na ACV foi o consumo de energia, resultando em maior impacto ambiental na categoria “cancerígenos”, agrupada na categoria de “danos à saúde”. Com base nestes resultados foi possível ainda minimizar os impactos propondo modificações principalmente nos sistemas de aquecimento que poderão ser utilizados.

Educação escolar de mulheres negras: interdições históricas...

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Giane Elisa Sales de Almeida

2011-12-01

Full Text Available O artigo aborda aspectos relativos a historia da educação de mulheres negras com base na analise dos fragmentos de memória disponibilizados pelos sujeitos da investigação. Procurando desenhar um perfil do que foi a trajetória educacional desse grupo, particularmente na cidade de Juiz de Fora,no estado brasileiro de Minas Gerais, no período 1950-1970, utilizou-se a historia oral como metodologia. Foram analisados aspectos relativos a cultura escolar e a democratização da escola publica no Brasil, bem como os modos como as políticas publicas voltadas a escolarização interferiram nas historias de vida das mulheres negras. O artigo relaciona as categorias raça, gênero e classe para o entendimento da fruição do direito a cidade e a escola publica como um importante equipamento urbano. Discute os modos como as políticas publicas são apreendidas e os limites interpostos no cotidiano escolar. O artigo aborda aspectos relativos a historia da educação de mulheres negras com base na analise dos fragmentos de memória disponibilizados pelos sujeitos da investigação. Procurando desenhar um perfil do que foi a trajetória educacional desse grupo, particularmente na cidade de Juiz de Fora,no estado brasileiro de Minas Gerais, no período 1950-1970, utilizou-se a historia oral como metodologia. Foram analisados aspectos relativos a cultura escolar e a democratização da escola publica no Brasil, bem como os modos como as políticas publicas voltadas a escolarização interferiram nas historias de vida das mulheres negras. O artigo relaciona as categorias raça, gênero e classe para o entendimento da fruição do direito a cidade e a escola publica como um importante equipamento urbano. Discute os modos como as políticas publicas são apreendidas e os limites interpostos no cotidiano escolar.

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)

ESTUDO DA SELETIVIDADE CAPACIDADE EM SISTEMAS SÓLIDO-GÁS

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A. M. SOUZA

1997-12-01

Full Text Available A solubilidade de compostos pesados em fase gasosa contendo um componente supercrítico (equilíbrio sólido-gás foi analisada, adotando-se a equação de estado de Peng-Robinson para representar os sistemas sólido-gás estudados. A modelagem foi aplicada para vários sistemas binários (monossólido/monossolvente e multissólido/multissolvente. Para cada sistema, fez-se a estimação dos parâmetros pertinentes, os parâmetros de interação binária, obtidos por regressão não linear a partir dos dados experimentais de equilíbrio sólido-gás correspondentes. Tendo como base os dados binários, foi realizada uma análise de seletividade/ capacidade de sistemas do tipo 2 sólidos-1solvente, comparando-os com dados experimentais, e fez-se a comparação com os sistemas ternários experimentais.The solubility of heavy compounds in gaseous phase containing a supercritical component (solid-gas equilibrium was analised. It was adopted the state equation of Peng-Robinson, to represent the solid-gas systems considered. The model was applied to several cases ranging from binary systems (mono-solid/mono-solvent to multi-solid/multi-solvent systems. For each system, it was done the estimation of pertinent parameters, the binary interaction parameters, obtained by non-linear regression from experimental data of correspondent solid-gas equilibrium. Using the results obtained from binary systems, predictions of selectivity/capacity for ternary systems like 2 solids-1 solvent were accomplished, and then a comparison with experimental data of ternary systems was achieved.

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.

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)

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)

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)

Constituintes químicos voláteis de especiarias ricas em eugenol

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Rosilene Aparecida de Oliveira

Full Text Available Utilizando a técnica de hidrodestilação, usando um adaptador Clevenger, foram extraídos óleos essenciais das espécies Pimenta dioica (folhas e frutos e Syzygium aromaticum (botões florais, talos e folhas. A composição química dos óleos foi determinada através da analise CG-EM. Os teores de óleos essenciais variaram de 0,97 a 1,41% e 2,30 a 15,40% nas espécies Pimenta dioica e Syzygium aromaticum, respectivamente. O componente majoritário presente nessas espécies foi o eugenol, variando de 72,87 a 90,41%. Syzygium aromaticum forneceu maior teor de óleo essencial rico em eugenol. Em quantidades menores foram também encontrados chavicol e? β-cariofileno.

Estimation grade of uranium from drill hole gamma logs

International Nuclear Information System (INIS)

Juliao, B.

1986-01-01

Radiometric grade of uranium deposits can be determined from drill hole gamma logs. The calculation of uranium oxide content can be obtained with good precision when the uranium ore is in radioactive equilibrium, containing only a small amount of thorium and no interference of potassium. This is the case of uranium ore from the Lagoa Real Uranium Province presented in this paper. The radioactive disequilibrium study in this province were made working over nine hundred samples analised with this special purpose in the CDTN-NUCLEBRAS laboratories. The data obtained indicated that the uranium in the ore is in perfect equilibrium with their daughter gamma emitters. Futhermore, the amount of Th and K is of no significance, so that the gamma counting represents exactly the uranium content of the ore. (author) [pt

A CRISE ESTRUTURAL DOS JORNAIS Uma exploração comparativa sobre a situação nos EUA e no Brasil

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Carlos Alves Müller

2011-10-01

Full Text Available Os jornais dos principais países desenvolvidos vivem uma crise frequentemente atribuída ao desenvolvimento das mídias digitais. Essa situação parece não se reproduzir nas maiores economias emergentes. O presente trabalho sustenta que, embora o surgimento e avanço dessas mídias tenham efetivamente afetado negativamente o desempenho das empresas jornalísticas, a crise em questão é estrutural e suas origens antecedem o surgimento das mídias digitais. A hipótese de que a situação dos países emergentes seja estruturalmente diversa é testada e, acredita-se, refutada por meio de uma analise comparativa da evolução recente do negócio jornal nos EUA e no Brasil.

LEITURA DA CRIAÇÃO: OS MANUSCRITOS LITERÁRIOS COMO UM SISTEMA COMPLEXO

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Sergio Romanelli

2014-05-01

Full Text Available Neste artigo apresento o paradigma emergente da ciência contemporânea e a noção de sistema, mostrando como tais princípios podem ser aplicados à analise de textos e manuscritos literários. Desejo indagar como os métodos da assim chamada ciência da complexidade podem ser aplicados aos estudos do processo de criação literária. Considero a escrita como um sistema complexo, que se caracteriza por três pressupostos: da complexidade, da instabilidade e da intersubjetividade. Desejo ainda demonstrar como o pensamento sistêmico aplicado ao estudo dos manuscritos literários, não somente permite localizar, estudar e processar as leis e recorrências que regem tais processos, mas, sobretudo, ajuda a destacar o papel dos criadores.

A utilização de mini-estações de tratamento de esgoto em residências

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Nícolas Fernandes Martins

2013-09-01

Full Text Available O presente trabalho tratará do desenvolvimento de um protótipo de estação detratamento de esgoto (ETE, sendo um protótipo onde foram analisados dadosquímicos e levantamento da microfauna do lodo ativado.  Foram analisados antes eapós o tratamento do protótipo dados referentes à Demanda Bioquímica de Oxigênio(DBO, Nitrogênio Amoniacal, fosfato, óleos e graxas, ph e espectrofotometria. É oprimeiro trabalho que utiliza medidas de espectrofotometria em analises de águastratadas. Todos os resultados comprovam que a estação de tratamento pode ser eficazem residências que não possuem tratamento de esgoto. Foram realizadas plantas parainstalação de uma estação de tratamento em residências.

Consequências psicossociais na partilha de emoções em situações interpessoais e em rituais colectivos

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Bernard Rimé

2012-02-01

Full Text Available A partir da teoria dos rituais colectivos (1912 de Émile Durkheim e baseando-se em exemplos práticos – os atentados do 11 de Março em Madrid, ou os rituais gacaca no Ruanda – Bernard Rimé, psicólogo e investigador da Universidade de Lovaina, Bélgica, analisa as consequências psicossociais da partilha de emoções em situações interpessoais e em rituais colectivos.Building upon Durkheim’s (1912 theory of collective rituals and upon practical exemples – the terrorist atacks of March 11 in Madrid and the gacaca rituals in Rwanda – Bernard Rimé, psychologist and researcher at the University of Louvain, Belgium, analises the psychosocial consequences of sharing emotions in interpersonal situations and collective rituals.

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.

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.

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

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)

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.

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)

INTEGRATED AUTOMOTIVE MANUFACTURING SUPPLY

Directory of Open Access Journals (Sweden)

P.J.S. Van Dyk

2012-01-01

Full Text Available

ENGLISH ABSTRACT: Supply planning and traffic flow planning are major activities in the automotive manufacturing environment worldwide. Traditionally, the impact of supply planning strategies on plant traffic is rarely considered. This paper describes the development of a Decision Support System (DSS that will assist automotive manufacturers to analyse the effect of supply planning decisions on plant traffic during the supply planning phase of their logistics planning process. In essence, this DSS consists of a Supply Medium Decision Support Tool (SMDST (an interactive MS-Excel model with Visual Basic interfacing and a traffic flow simulation model tool (using eMPlant simulation software.

AFRIKAANSE OPSOMMING: Verskaffingsbeplanning en verkeersvloeibeplanning is belangrike aktiwiteite in die motorvervaardigingsbedryf wêreldwyd. Tradisioneel word die uitwerking van verskaffings-beplanningsstrategië op aanlegverkeer selde in ag geneem. Hierdie artikel beskryf die ontwikkeling van ’n Besluitnemings Ondersteuningstelsel (DSS wat motorvervaardigers sal ondersteun in die analise van die effek van verskaffingsbeplanningbesluite op aanlegverkeer tydens die verskaffingsbeplanningsfase van hulle logistieke beplanningsproses. Hierdie DSS bestaan hoofsaaklik uit ’n Verskaffings-vervoermiddel Besluitnemingshulpmiddel (SMDST (’n interaktiewe MS-Excel model met “Visual Basic” koppelling asook ’n simulasiemodel van verkeersvloei (met eM-Plant simulasiesagteware.

Pulsating Heat pipe Only for Space (PHOS): results of the REXUS 18 sounding rocket campaign

International Nuclear Information System (INIS)

Creatini, F; Guidi, G M; Belfi, F; Cicero, G; Fioriti, D; Di Prizio, D; Piacquadio, S; Becatti, G; Orlandini, G; Frigerio, A; Fontanesi, S; Nannipieri, P; Rognini, M; Morganti, N; Filippeschi, S; Di Marco, P; Fanucci, L; Baronti, F; Mameli, M; Manzoni, M

2015-01-01

Two Closed Loop Pulsating Heat Pipes (CLPHPs) are tested on board REXUS 18 sounding rocket in order to obtain data over a relatively long microgravity period (approximately 90 s). The CLPHPs are partially filled with FC-72 and have, respectively, an inner tube diameter larger (3 mm) and slightly smaller (1.6 mm) than the critical diameter evaluated in static Earth gravity conditions. On ground, the small diameter CLPHP effectively works as a Pulsating Heat Pipe (PHP): the characteristic slug and plug flow pattern forms inside the tube and the heat exchange is triggered by thermally driven self-sustained oscillations of the working fluid. On the other hand, the large diameter CLPHP works as a two- phase thermosyphon in vertical position and doesn't work in horizontal position: in this particular condition, the working fluid stratifies within the device as the surface tension force is no longer able to balance buoyancy. Then, the idea to test the CLPHPs in reduced gravity conditions: as the gravity reduces the buoyancy forces becomes less intense and it is possible to recreate the typical PHP flow pattern also for larger inner tube diameters. This allows to increase the heat transfer rate and, consequently, to decrease the overall thermal resistance. Even though it was not possible to experience low gravity conditions due to a failure in the yoyo de-spin system, the thermal response to the peculiar acceleration field (hyper-gravity) experienced on board are thoroughly described. (paper)

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)

Nocturnal reverse flow in water-in-glass evacuated tube solar water heaters

International Nuclear Information System (INIS)

Tang, Runsheng; Yang, Yuqin

2014-01-01

Highlights: • Performance of water-in-glass evacuated tube solar water heaters (SWH) at night was studied. • Experimental measurements showed that reverse flow occurred in SWHs at night. • Reverse flow in SWHs was very high but the heat loss due to reverse flow was very low. • Reverse flow seemed not sensitive to atmospheric clearness but sensitive to collector tilt-angle. - Abstract: In this work, the thermal performance of water-in-glass evacuated tube solar water heaters (SWH) at nights was experimentally investigated. Measurements at nights showed that the water temperature in solar tubes was always lower than that in the water tank but higher than the ambient air temperature and T exp , the temperature of water inside tubes predicted in the case of the water in tubes being naturally cooled without reverse flow. This signified that the reverse flow in the system occurred at nights, making the water in solar tubes higher than T exp . It is found that the reverse flow rate in the SWH, estimated based on temperature measurements of water in solar tubes, seemed not sensitive to the atmospheric clearness but sensitive to the collector tilt-angle, the larger the tilt-angle of the collector, the higher the reverse flow rate. Experimental results also showed that, the reverse flow in the SWH was much higher as compared to that in a thermosyphonic domestic solar water heater with flat-plate collectors, but the heat loss from collectors to the air due to reverse flow in SWHs was very small and only took about 8–10% of total heat loss of systems

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)

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)

'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 ...

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)

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...

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)

Neural network modeling of chaotic dynamics in nuclear reactor flows

International Nuclear Information System (INIS)

Welstead, S.T.

1992-01-01

Neural networks have many scientific applications in areas such as pattern classification and time series prediction. The universal approximation property of these networks, however, can also be exploited to provide researchers with tool for modeling observed nonlinear phenomena. It has been shown that multilayer feed forward networks can capture important global nonlinear properties, such as chaotic dynamics, merely by training the network on a finite set of observed data. The network itself then provides a model of the process that generated the data. Characterizations such as the existence and general shape of a strange attractor and the sign of the largest Lyapunov exponent can then be extracted from the neural network model. In this paper, the author applies this idea to data generated from a nonlinear process that is representative of convective flows that can arise in nuclear reactor applications. Such flows play a role in forced convection heat removal from pressurized water reactors and boiling water reactors, and decay heat removal from liquid-metal-cooled reactors, either by natural convection or by thermosyphons

EN-CV during LS1: upgrade, consolidation, maintenance, operation

International Nuclear Information System (INIS)

Nonis, M.

2012-01-01

The Cooling and Ventilation (CV) Group in the Engineering Department (EN) will be heavily involved in several projects and activities during the long shutdown in 2013 and 2014 (LS1) within a time-frame limited to around twelve months. According to the requests received so far, most projects are related to the upgrade of users' equipment, consolidation work, and the construction of new plants. However, through the experience gained from the first years of the LHC run, some projects are also needed to adapt the existing installations to the new operating parameters. Some of these projects are presented hereafter, outlining the impact that they will have on operational working conditions or risks of breakdown. Among these projects we find: the PM32 raising pumps, the cooling of the CERN Control Center, R2E, the backup cooling towers for ATLAS and cryogenics, a thermosyphon for ATLAS, or new pumps in UWs. Finally, EN-CV activities during LS1 for maintenance, operation, and commissioning will be mentioned since they represent a major workload for the Group

SCIENCE EDUCATION IN SCHOOLS AND AT TERTIARY LEVEL: STATUS QUO OR EMBRACING CHANGE?

Directory of Open Access Journals (Sweden)

André du Plessis

2018-04-01

Full Text Available Society is changing as the influence of technologies and the implementation of innovative practices are driving change. Change and innovation are not simple processes for all (Rogers, 2003. Yet, companies, corporates and small business are managed and lead to ensure not only efficiency, but also to yield the best possible financial gain. When one analises change in the world of commerce, one does not have to be a rocket scientist to come to the conclusion that there have been tremendous changes. Not only has the ergonomics of buildings and factories changed, there has also been change pertaining to the number of people employed, as technologies afford opportunities to make certain positions that people occupied, redundant. Robotic tools are used more and more in the manufacturing chain to increase productivity and to ensure greater quality, or so we are informed.

A FRAGILIDADE DA PREVALÊNCIA DO NEGOCIADO SOBRE O LEGISLADO

Directory of Open Access Journals (Sweden)

Juliana Machado Sorgi

2017-06-01

Full Text Available O presente artigo aborda, através de pesquisa bibliográfica, a problemática da prevalência do negociado sobre o legislado no Direito do Trabalho. Tem por objetivo apontar a insegurança jurídica que essa prática pode trazer, sem, contudo, alcançar real redução do desemprego e/ou fomento da economia, como se promete. Para tanto, utiliza-se de analises de decisões do STF e do Projeto de Lei da Reforma trabalhista, trazendo como contraponto a realidade da liberdade sindical do Brasil. Conclui ser temerária, da forma como proposta, a prevalência da negociação coletiva, elaborada em espaço de esparsa participação popular, em detrimento da legislação trabalhista, democraticamente conquistada.

Jovens negros em conflito com a lei: escola e trajetórias

Directory of Open Access Journals (Sweden)

Vilma Aparecida de Pinho Pinho

2011-12-01

Full Text Available O trabalho busca investigar as trajetórias de vida e de escolarização de jovens negros em processo de “ressocializacao", visando averiguar os fatores sociais que os levaram a ser considerados em conflito com alei. As analises foram realizadas a luz doaporte teórico das relações etnico-raciais,com ênfase nos enfoques teorico-metodologicos da dialética e da fenomenologia. Os resultados indicam que as condições de pobreza material e não material herdadas de gerações anteriores e o contexto escolar contribuem fortemente para a construção da situação atual desses jovens, que enfrentam a naturalização do racismo, evidenciada em diferentes momentos das narrativas produzidas pelos componentes do universo empírico desta pesquisa.

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)

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)

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)

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)

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)

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)

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)

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)

THE IMPLEMENTATION OF THE INTERNAL AUDIT IN THE PUBLIC SECTOR FROM ROMANIA

Directory of Open Access Journals (Sweden)

George CALOTĂ

2009-12-01

Full Text Available In compliance with the European requirements, Romania started implementing internal audit in the public sector in 1999 through the reform at the level of the Public Internal Financial Control System. To set the startegic directions on a short and medium term for public internal financial control in Romania, the Strategy for Developing the Public Internal Financial Control in Romania has been developed and it was finalised in October 2001. This document set up the architecture for the new internal audit system in the public sector. Negociations for Chapter 28 – Financial Control started during the Intergovernmental Conference Romania – EU from June 28th 2002, in compliance with the Common Position of the European Union, and the implementation of the Action Plan for the new system was done in several stages: a Setting up the legal framework for internal audit, including norms and procedures; b Institution building, namely reengineering the old internal control structures; c Professional training; d Strengthening the internal audit activity by raising the awareness of the management on the internal audit role; After analising the current stage of implementation for internal audit in the public sector, we may conclude that Romania is on the right track, supporting the set-up and strengthening of the internal audit function at the level of the entities, in accordance with the good practice in the field. To conclude, the efforts made to harmonise the national legislation in this field with the acquis communautaire should proceed, focusing on even stricter requirements, so that an harmonisation between the Romanian legislative framework, the European Union directives and the International Audit Standards may be achieved

Overview report of RAMONA-NEPTUN program on passive decay heat removal

International Nuclear Information System (INIS)

Weinberg, D.; Rust, K.; Hoffmann, H.

1996-03-01

The design of the advanced sodium-cooled European Fast Reactor provides a safety graded decay heat removal concept which ensures the coolability of the primary system by natural convection when forced cooling is lost. The findings of the RAMONA and NEPTUN experiments indicate that the decay heat can be safely removed by natural convection. The operation of the decay heat exchangers being installed in the upper plenum causes the formation of a thermal stratification associated with a pronounced temperature gradient. The vertical extent of the stratification and the qualitity of the gradient are depending on the fact whether a permeable or an impermeable shell covers the above core structure. A delayed startup time of the decay heat exchangers leads only to a slight increase of the temperatures in the upper plenum. A complete failure of half of the decay heat exchangers causes a higher temperature level in the primary system, but does not alter the global temperature distribution. The transient development of the temperatures is faster going on in a three-loop model than in a four-loop model due to the lower amount of heat stored in the compacter primary vessel. If no coolant reaches the core inlet side via the intermediate heat exchangers, the core remains coolable. In this case, cold water of the upper plenum penetrates into the subassemblies (thermosyphon effects) and the interwrapper spaces existing in the NEPTUN core. The core coolability from above is feasible without any difficulty though the temperatures increase to a minor degree at the top end of the core. The thermal hydraulic computer code FLUTAN was applied for the 3D numerical simulation of the majority of the steady state RAMONA and NEPTUN tests as well as for selected transient RAMONA tests. (orig./HP) [de

Phase C commissioning-Cernavoda Unit 2

International Nuclear Information System (INIS)

Munro, Robert

2007-01-01

Phase C commissioning program includes over 500 individual tests and checks which are carefully planned and scheduled at the correct power level. Some of the major tests are the following: - heat transport thermosyphoning test at 3% Full Power (FP); - dual computer failure test at 15% FP; - turbine overspeed test and generator first synchronization; - load rejection tests at 25, 50, 75 and 100% FP; - loss of Class IV Power test at 25% FP; - shutdown system (SDS nr. 1 and SDS nr. 2) tests at >60% FP; - condensate extraction and boiler feedwater pump trip tests at 100% FP; - power cycling through reactor setback from 100 to 10 and back to 100% FP; - condenser steam discharge valve tests with reactor at 100% FP and turbine at 60% output; - low pressure and high pressure heater box-up tests at 100% FP. Progress through the Phase C program is controlled at six specific Commissioning Control Points (CCPs) which meet the Romanian Regulatory Authority (CNCAN) and Management requirements. These CCPs are the following: PI - Approval for Power increase to 5% FP; PP1 - Approval for Power increase to 25% FP; PP2 - Approval for Power increase to 50% FP; PP3 - Approval for Power increase to 75% FP; PP4 - Approval for Power increase to 100% FP. Prior to releasing each of these CCPs both Management and CNCAN complete an assessment of the 'Readiness' to proceed to the next power plateau. The readiness includes a review of the plant material condition, results of previous tests, documentation status, and operability maintainability issues. (author)

A Apa da Baleia Franca e o Turismo de Observação de Baleias Embarcado (Tobe: Sustentabilidade ou Exploração Animal?

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Fernanda Luiza Fontoura de Medeiros

2015-12-01

Full Text Available O Sistema Nacional de Unidades de Conservação, regulado pela Lei 9985/2000, estabelece duas grandes categorias de Unidades de Conservação: as unidades de conservação de proteção integral e as unidades de conservação de uso sustentável. Entre as unidades de conservação de uso sustentável, as áreas de proteção ambiental caracterizam-se por serem áreas extensas, instituídas para a preservação dos processos naturais e da biodiversidade, bem como para regular as atividades humanas às características ambientais da área. Assim, no sul do estado de Santa Catarina foi instituída a Área de Proteção Ambiental da Baleia Franca (APABF, com o objetivo principal de proteger nas aguas brasileiras a baleia franca austral. Recentemente, a APABF esta sendo palco de um intenso conflito socioambiental em razão da Ação Civil Pública (ACP interposta pelo Instituto Sea Shepherd Brasil em face do Instituto Chico Mendes da Biodiversidade (ICMBIO, pedindo a condenação do ICMBIO a adotar de forma permanente, as medidas necessárias e eficazes para a proteção das baleias-francas, mediante a fiscalização das empresas que praticam a observação das baleias com uso de embarcações, com ou sem motor, a fim de impedir a violação da legislação. Este artigo consiste em um estudo de caso e visa contribuir para o conhecimento do caso do turismo de observação de baleias embarcado na APABF, através da analise da legislação aplicada, como dos atores envolvidos na controvérsia judicial e o seu reflexo para os direitos animais. A pesquisa é feita através da analise documental da legislação que caracteriza as unidades de conservação, da legislação especifica de proteção aos cetáceos, bem como dos argumentos utilizados pelas partes envolvidas na ACP.

Studies on magnetocaloric and magnetic coupling effects =

Science.gov (United States)

Amaral, Joao Cunha de Sequeira

O presente trabalho apresenta novas metodologias desenvolvidas para a analise das propriedades magneticas e magnetocaloricas de materiais, sustentadas em consideracoes teoricas a partir de modelos, nomeadamente a teoria de transicoes de fase de Landau, o modelo de campo medio molecular e a teoria de fenomeno critico. Sao propostos novos metodos de escala, permitindo a interpretacao de dados de magnetizacao de materiais numa perspectiva de campo medio molecular ou teoria de fenomeno critico. E apresentado um metodo de estimar a magnetizacao espontanea de um material ferromagnetico a partir de relacoes entropia/magnetizacao estabelecidas pelo modelo de campo medio molecular. A termodinamica das transicoes de fase magneticas de primeira ordem e estudada usando a teoria de Landau e de campo medio molecular (modelo de Bean-Rodbell), avaliando os efeitos de fenomenos fora de equilibrio e de condicoes de mistura de fase em estimativas do efeito magnetocalorico a partir de medidas magneticas. Efeitos de desordem, interpretados como uma distribuicao na interaccao magnetica entre ioes, estabelecem os efeitos de distribuicoes quimicas/estruturais nas propriedades magneticas e magnetocaloricas de materiais com transicoes de fase de segunda e de primeira ordem. O uso das metodologias apresentadas na interpretacao das propriedades magneticas de variados materiais ferromagneticos permitiu obter: 1) uma analise quantitativa da variacao de spin por iao Gadolinio devido a transicao estrutural do composto Gd5Si2Ge2, 2) a descricao da configuracao de cluster magnetico de ioes Mn na fase ferromagnetica em manganites da familia La-Sr e La-Ca, 3) a determinacao dos expoentes criticos β e δ do Niquel por metodos de escala, 4) a descricao do efeito da pressao nas propriedades magneticas e magnetocaloricas do composto LaFe11.5Si1.5 atraves do modelo de Bean-Rodbell, 5) uma estimativa da desordem em manganites ferromagneticas com transicoes de segunda e primeira ordem, 6) uma descricao de

Estudo de propriedades estruturais e opticas de multicamadas epitaxiais emissoras de luz baseadas em InGaN/GaN

Science.gov (United States)

Pereira, Sergio Manuel de Sousa

Esta tese apresenta os resultados de uma investigacao experimental em filmes epitaxiais emissores de luz baseados em InxGa1-xN. O InxGa1-xN e uma liga semicondutora ternaria do grupo III-N muito utilizada como camada activa numa gama de dispositivos optoelectronicos em desenvolvimento, incluindo diodos emissores de luz (LEDs) e diodos laser (LDs), para operacao na regiao do visivel e ultravioleta do espectro electromagnetico. Neste estudo, caracterizam-se as propriedade opticas e estruturais de camadas simples e pocos quânticos multiplos (Multiple Quantum Wells, MQWs) de InxGa1-xN/GaN, com enfase nas suas propriedades fisicas fundamentais. O objectivo central do trabalho prende-se com a compreensao mais profunda dos processos fisicos que estao por tras das suas propriedades opticas, preenchendo o fosso existente entre aplicacoes tecnologicas e o conhecimento cientifico. Nomeadamente, a tese aborda os problemas da medicao da fraccao de InN (x) em multicamadas ultrafinas sujeitas a tensoes, a influencia da composicao e das tensoes microscopicas nas propriedades opticas e estruturais. A questao relativa a segregacao de fases em multicamadas de InxGa1-xN/GaN e tambem discutida a luz dos resultados obtidos. A metodologia seguida assenta na integracao de resultados obtidos por tecnicas complementares atraves de uma analise sistematica e multidisciplinar. Esta abordagem passa pela combinacao de: 1) Crescimento de amostras por deposicao epitaxial em fase de vapor organometalico (MOVPE) com caracteristicas especificas de forma a tentar isolar parâmetros estruturais, tais como espessura e composicao; 2) Caracterizacao nanoestrutural por microscopia de forca atomica (AFM), microscopica electronica de varrimento (SEM), difraccao de raios-X e retro-dispersao de Rutherford (RBS); 3) Caracterizacao optica a escalas complementares por: espectroscopia de absorcao optica (OA), fotoluminescencia (PL), catodoluminescencia (CL) e microscopia confocal (CM) com analise espectral. Com

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

Folksonomia: a linguagem das tags

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Juliana de Assis

2013-01-01

Full Text Available A radicalização do potencial colaborativo da web atual aponta uma tendência de personalização da recuperação da informação através de ferramentas que exploram a linguagem natural na representação e no compartilhamento de conteúdos ao longo das redes sociais. Tal configuração sócio-técnica traz desafios aos profissionais da informação tanto para a descrição e compreensão dos fenômenos informacionais que ocorrem neste âmbito, quanto para a elaboração de produtos e serviços voltados para um usuário que se apresenta cada vez mais como sujeito informacional ao assumir um papel ativo diante da complexidade que caracteriza a organização da informação em contextos digitais. Este artigo apresenta conclusões de pesquisa, relacionadas às analises da linguagem utilizada em três ambientes colaborativos que utilizam a folksonomia (Social Tagging Systems. A partir de uma perspectiva fundamentada na Semiótica e na Análise de Redes Sociais, são identificadas e descritas as principais manifestações da linguagem gerada e compartilhada pelas redes sociais através destes ambientes.

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)

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...

’n Retoriese analise van Romeine 9:1–10:4

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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.

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)

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...

[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.

THE DISCOURSE OF THE DIVERSITY ETHNIC-RACIAL AND THE GOVERNMENT OF THE DIFFERENCES IN THE BLACK SUBJECT FORMATION

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Viviane Inês Weschenfelder

2013-04-01

Full Text Available The goal of this article is to present how the ethnical racial diversity discourse is structured in Venâncio Aires county, RS and in what way it contributes to the formation of the black citizen of Venancio Aires. The analisys of Folha do Mate NewsPaper, the main printed media of the current county, allowed to recognize an ocurred discursive shift, especially, from 1988. As characteristic of Contemporary, the diversity discourse tries to evidence how different cultures live peacefully in the same space, when work around any indication of conflict that may ocurr by the difference, it contributes to the black person formation. From the orientations of the post-structuralist perspectives and from the analitical tools of Michel Foucault, the analises of the discourse intends to enable an important debate in the education field, specially in relation to the forms of governments of the individuals.

Do coitadinho ao super-herói Representação social dos atletas paralímpicos na mídia brasileira e portuguesa

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Tatiane Hilgemberg

2014-06-01

Full Text Available Since its begining the society tended to marginalize and disqualify people with disabilities giving to them the stigma of difference. Even nowadays, and although we live at a society so called inclusive, the prejudice against the athletes with disability is still prevailing. Every individual that goes against the normality patterns is considered stigmatized. The aim of this study is to analyse the media coverage of paralympic athletes at the Brazilian and Portuguese media at the Paralympic Games in Atlanta/96, Sydney/2000, Athens/2004 and Beijing/2008. From our analyses we could, in summary, conclude that the media coverage of this Paralympic Games in Brazil and Portugal has more similarities than differences. In both countries the pitiful handicapped and the super hero stereotypes were found, with a tendency to the super hero, and the differences were the percentual variations between the analised editions.

Componentes Estruturais e Conjuntos Parcimoniosos na Explicação do Desempenho Organizacional: Um Estudo nos Setores da Indústria e Serviço

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Carlos Alberto Gonçalves

2013-09-01

Full Text Available Este estudo apresenta a aplicação do método ACQ - Analise Comparativa Qualitativa como forma de identificar configurações estratégicas parcimoniosas por conjuntos de fatores explicativos do desempenho das firmas. O método possui capacidade de formular conjuntos intitulados parcimoniosos, reduzidos e com capacidade para explicar causalidades em uma variável dependente. O construto Desempenho é de natureza formativa e, no caso do trabalho, é proposto como multidimensional, modelado como teleológico (cadeia sense making vis a vis antecedentes como Inovação e Aprendizado, Estrutura do Setor, Perfil Empreendedor, Capacidade de Risco, Análise de Cenários, Formação da Estratégia, Capacidades Dinâmicas como gradações abstratas de ampla latência. DOI:10.5585/riae.v12i3.1982

SIMILAR ASPECTS OF KAINGANG, XAVANTE AND BORORO SOCIAL ORGANIZATION

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Juliana Soares

2008-06-01

Full Text Available Durante o desenvolvimento do Projeto Taió (Arqueologia do Planalto Catarinense, foram realizadas pesquisas etno-históricas a respeito dos Jê Meridionais - Tradição Taquara/Itararé e seus descendentes Kaingang. Os resultados desses estudos levaram a necessidade de obter dados que permitam discutir como se constituiu a identidade étnica do grupo, percebendo de que maneira o processo migratório para a Região Sul influenciou sua especificidade cultural. A estratégia utilizada para abordar a questão foi perceber o Kaingang dentro do contexto dos Povos Jê, confrontando-o, através de analise comparativa, com as sociedades Xavante e Bororo a fim de mapear elementos distintos e comuns de suas estruturas de organização social. Os resultados obtidos vêm auxiliar os estudos culturais Kaingang e a interpretação de dados arqueológicos.

THE SOCIAL NETWORK FOR CONFRONTING CONJUGAL VIOLENCE: REPRESENTATIONS OF WOMEN WHO EXPERIENCE THIS HEALTH ISSUE

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Nadirlene Pereira Gomes

2015-01-01

Full Text Available Esto es un estudio cualitativo, basado en la Teoria de las Representaciones Sociales, cuyo objetivo es de describir, a traves las representaciones de mujeres que tuvieran historia de violencia conyugal, los elementos que constituyen la rede social de enfrentamiento del problema. 11 mujeres que tuvieran historia de violencia conyugal fueran entrevistadas. Los dados fueran categorizados por medio de la analise tematica. Lo estudio muestra que la ayuda de la religion, de la familia, de los amigos y de ONGs como el colectivo de mujeres calafate ayuda las mujeres a se sentiren amparadas, y eso ayuda en su busca por una vida sin violencia. El conocimiento acerca de la rede de apoyo disponivel en la comunidad por profisionales que atuan en espacios de salud es fondamental, sobretodo cuando los elementos que lo integran refleten las representaciones de certo grupo, configurando, portanto, un conocimiento comun compartido por la comunidad.

Mimeses do sublime: a recepção de Kant pelo Romantismo e pelo Expressionismo Mimesis of sublime: the Romantism and Expressionism reception of Kant

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Priscila Rossinetti Rufinoni

2007-01-01

Full Text Available Partindo das analises do criticismo kantiano, este texto investiga as concepções romântica e moderna de sublime e de imaginação. Se, por um lado, a concepção romântica inaugura o mundo moderno, por outro, a expressionista mostra os limites dessa mesma modernidade. Para ambas, entretanto, a Crítica do Juízo de Kant é o âmbito privilegiado no qual podemos precisar as distinções.Starting from the analysis of the Kantian criticism, this text investigates the romantic and the modern conceptions of sublime and imagination. On the one hand, the romantic conceptions of sublime inaugurate the modern world. On the other hand, the expressionist conceptions show the confines of this world. The Critique of Judgment is the very locus where such distinctions can be drawn with precision.

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.

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

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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.

Design and simulation of a heat transformer of a directly solar-driven diffusion absorption chiller; Auslegung und Simulation von Waermeuebertragern einer direkt solarthermisch angetriebenen Diffusions-Absorptionskaeltemaschine

Energy Technology Data Exchange (ETDEWEB)

Hong, Josua; Schmid, Fabian; Spindler, Klaus [Stuttgart Univ. (DE). Inst. fuer Thermodynamik und Waermetechnik (ITW)

2011-07-01

The ITW is working on a directly solar-driven diffusion absorption chiller. Solar cooling offers vast potential for saving fossil resources, e.g. owing to the good temporal agreement between insolation and cold demand for cooling of office buildings and domestic buildings. So far, the focus has been on central systems with indirect solar thermal operation. Direct solar thermal plants can be decentral. A diffusion-absorption refrigeration system without mechanical components was constructed. Solvent circulation is achieved by the thermosyphon principle, which makes the plant noiseless, wear-free, and low-maintenance. In the course of a study, a mathematical model of the heat exchangers was established on the basis of the heat transfer equations, and optimisation suggestions for the heat exchanger were identified on this basis. The influence of the pressure gradient - which is decisive -, and the influence of geometry and materials were investigated. The simulations were validated by measurements. Concrete optimisation potentials were identified, and first suggestions were implemented. [German] Am ITW wird intensiv an einer direkt solarthermisch angetriebenen Diffusions-Absorptionskaeltemaschine (DAKM) geforscht. Die solare Kuehlung bietet grosse Potentiale zur Einsparung fossiler Energietraeger. Ein Grund dafuer ist die gute zeitliche Uebereinstimmung zwischen Solarstrahlung und dem Kaeltebedarf fuer die Kuehlung von Wohngebaeuden und Bueros. Bislang standen zentrale und indirekt solarthermisch angetriebene Systeme zur Kaelteerzeugung im Fokus. Die direkt solarthermisch angetriebene Anlage kann auf Grund ihres neuen Konzepts dezentral aufgebaut und betrieben werden. Auf Grundlage des Diffusions-Absorptionskaelteprozesses wurde eine Anlage gebaut, die ohne mechanische Bauteile funktioniert. Der Loesungsmittelumlauf erfolgt durch das Thermosiphonprinzip. Dadurch ist die Anlage im Betrieb geraeuschlos, verschleissfrei und wartungsarm. Im Rahmen einer Studienarbeit

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)

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)

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)

An electrical analogy relating the Atlantic multidecadal oscillation to the Atlantic meridional overturning circulation.

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Bruce E Kurtz

Full Text Available The Atlantic meridional overturning circulation (AMOC is the northward flow of surface water to subpolar latitudes where deepwater is formed, balanced by southward abyssal flow and upwelling in the vicinity of the Southern Ocean. It is generally accepted that AMOC flow oscillates with a period of 60-80 years, creating a regular variation in North Atlantic sea surface temperature known as the Atlantic multidecadal oscillation (AMO. This article attempts to answer two questions: how is the AMOC driven and why does it oscillate? Using methods commonly employed by chemical engineers for analyzing processes involving flowing liquids, apparently not previously applied to trying to understand the AMOC, an equation is developed for AMOC flow as a function of the meridional density gradient or the corresponding temperature gradient. The equation is based on the similarity between the AMOC and an industrial thermosyphon loop cooler, which circulates a heat transfer liquid without using a mechanical pump. Extending this equation with an analogy between the flow of heat and electricity explains why the AMOC flow oscillates and what determines its period. Calculated values for AMOC flow and AMO oscillation period are in good agreement with measured values.

Active Control of Thermal Convection in a Rectangular Loop by Changing its Spatial Orientation

Science.gov (United States)

Bratsun, Dmitry A.; Krasnyakov, Ivan V.; Zyuzgin, Alexey V.

2018-02-01

The problem of the automatic control of the fluid flow in a rectangular convective loop heated from below is studied theoretically and experimentally. The control is performed by using a feedback subsystem which changes the convection regimes by introducing small discrete changes in the spatial orientation of the loop with respect to gravity. We focus on effects that arise when the feedback controller operates with an unavoidable time delay, which is cause by the thermal inertia of the medium. The mathematical model of the phenomenon is developed. The dynamic regimes of the convection in the thermosyphon loop under control are studied. It is shown that the proposed control method can successfully stabilize not only a no-motion state of the fluid, but also time-dependent modes of convection including the irregular fluid flow at high values of the Rayleigh number. It is shown that the excessive gain of the proportional feedback can result in oscillations in the loop orientation exciting the unsteady convection modes. The comparison of the experimental data obtained for dielectric oil and dodecane with theory is given, and their good agreement is demonstrated.

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)

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.

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)

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)

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)

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)

[Lead point as a poor prognostic factor in the therapy of invagination in children].

Science.gov (United States)

Djordjević, I M; Milićević, R; Djordjević, N; Karanikolić, A D; Ignjatović, N

2007-01-01

Invagination is specific form of bowel opstruction that is seen in 1-4 children per 1000 births, usually in the period from 3 to 12 months of age. In 90-95 % reason for invagination in unknown so we called this forms idiopathic. In 5-10% invagination is caused by specific leading point. THE AIM of this retrospective study was to determinate prognostic valye of used biochemical tests (hemograms, glucosa, electrolites ( levels of Na+, K+, Ca+ and Cl-) and to prove bad influence of existing "leading point" in therapy of invagination (weather it will be surgical or hydrostatic desinvagination). We analised 65 patients with invagination. We devided all our patients into 2 groups: first group consisted patients with idiopathic forms of invagination, and the other one were patients with invagination coused by specific leading point. RESULTS proved that leading point in invagination has great implications on clinical presentation, laboratory results, diagnostic and therapeutic procedure, and finaly in prognosis.

КЛИНИЧЕСКИЙ ОПЫТ РЕАЛИЗАЦИИ ИНВАЗИВНОЙ СТРАТЕГИИ ЛЕЧЕНИЯ ОСТРОГО КОРОНАРНОГО СИНДРОМА БЕЗ СТОЙКОГО ПОДЪЕМА СЕГМЕНТА ST НА ЭКГ

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Ю. А. Прилуцкая

2015-01-01

Full Text Available In article authors discuss invasive strategy of treatment of patients with acute coronary syndrome without ST elevation. 221 cases from CCU of hospital № 7 were analysed. There are some problems in pre-clinical diagnosis (half of cases were excluded diagnosis of acute coronary syndrome write after hospitalisation and hight specifity of preliminary clinical diagnosis, that was approved in 82% of cases. Only 26% of patients with acute coronary syndrome without ST elevation were refered to surgery (in 15 cases — percutaneous coronary intervention, in 3 — coronary artery bypass grafting. After analisation of medical histories authors find out patients to whom surgery was needed but wasn’t prescribed (in 29 cases — contrindications, in 23 — recomendation to deferred coronaroangiography and 15 were discharged without stress test performance. In situation we will use new diagnostical tools and methods we can find more cases of acute coronary syndrome without ST elevation.

The perception of midwives regarding psychosocial risk assessment during antenatal care

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Johanna M. Mathibe-Neke

2014-05-01

Doelwit: Die doelwit van hierdie studie was om die persepsies van vroedvroue, wat voorgeboortesorg aan swanger vrouens bied, te ondersoek en te beskryf sover dit hulle persepsies oor psigososiale risiko-assessering en psigososiale aangaan. Metode: ’n Interpretatiewe en beskrywende kwalitatiewe benadering is gevolg. Drie fokusgroep-onderhoude is deur middel van ‘n gestruktureerde onderhoudsgids gevoer met verloskundiges wat in drie voorgeboorteklinieke in die Gauteng Provinsie werksaam is. ’n Benadering tot data-analise wat van voortdurende vergelyking gebruik maak, is gevolg. Resultate: Die studie het aan die lig gebring dat verloskundiges bewus is van psigososiale probleme onder swanger vroue en dat die prevalensie van sulke probleme onder swanger vroue hoog is. Vroedvroue erken die belang van psigososiale sorg aan swanger vroue alhoewel hulle nie toereikend toegerus is om psigososiale assessering en -sorg te verleen nie. Gevolgtrekking: Die bevindinge stel ’n basis daar vir die insluiting van psigososiale sorg in roetine voorgeboortesorg.

Structure and diversity of ground mesofauna inUlmus and Populus consortia in the industrial areas of mining and smelting complex of krivyi rig basin

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V. V. Kachinskaya

2010-05-01

Full Text Available The structure and biological diversity of ground mesofauna on a consortium level of organisation of ecosystems are considered. Indicators of structural organisation and biodiversity of ground mesofauna were analised in Ulmus and Populus consortia in the conditions of industrial territories of mining and smelting complex of Krivyi Rig Basin. It is established that taxonomical structure of ground mesofauna is characterised by insignificant number and quantity of taxonomical groups. Prevalence of hortobionts and herpetobionts in morpho-ecological structure of the community testifies to their attachment to consortium’s determinants and influence of steppe climate on its structure. Dominance of phytophages and polyphages in trophic structure is caused by a combination of consortium determinants specificity and «a zone source» of the fauna formations. The structural organisation of ground mesofauna in consortia of Ulmus and Populus in the conditions of industrial sites is characterised by simplified taxonomical structure with low biodiversity at all levels.

High-Rise Construction in Densely Dwelled Cities: Requirements for Premises Insolation and Consequences of their Violation in Russian Law and Jurisprudence

Science.gov (United States)

Gongalo, Boris; Gudovicheva, Lubov; Gubareva, Anna; Dobrynina, Larisa

2018-03-01

The issues of constructing high-rise, primarily residential, buildings have a great social significance. Not every plot of land, acquired in the Russian Federation is suitable for high-rise construction. Therefore, every construction company that plans to erect a multi-apartment building, a high-rise office building, or a skyscraper must take into account not only technical norms but as well sanitary legislation regulations that set obligatory requirements about insolation of apartments. The article includes a short study of several norms in the Russian legislation regarding insolation of dwellings; analises the problems of judicial interpretation of the statutory limitations. In this aspect it researches the debatable questions arising in practice of state arbitration courts dealing with the lawsuits on allocation of land-plots by the local administration. The analysis of the judicial practice is followed by description of the difficulties facing the developers of land-plots, concerning the project and territorial planning documentation.

A comparative study of health hazards and environmental impacts for electricity generation through nuclear energy hidroelectricity and coal fired thermoeletrical generation

International Nuclear Information System (INIS)

Guimaraes, C.A.

1982-01-01

Environmental impacts and health hazards were comparatively assessed in regard to electricity generation via nuclear energy, hidraulic dams and coal firing. The main aspects covered the nuclear reactor and its associated nuclear fuel cycle, coal fired thermoelectrical power plant its associated coal industry, and hidroelectrical power plant and its dam. Besides specific comparisons of impacts in the air, water, soil and health hazards an evaluation for the Brazilian case was made based on a forecast of electricity demand up to the year 2020. For the nuclear option the consequences were analysed based on American data since no data is yet available for Brazil. Coal firing option was also analised for based heavily on American data due to small Brazilian experience in this sector of energy generation. For hydroelectrical option Brazilian data were used mostly from CESP for comparative purposes. These alternatives for generation of electricity considered in this study are the most relevant for the next four decades for Brazil. (Author) [pt

O uso do clítico na fala culta de Fortaleza

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Emanuela Monteiro GONDIM

2012-05-01

Full Text Available

Este trabalho visa verificar a ocorrência ou o apagamento do clítico nos verbos pronominais na fala de informantes cultos de Fortaleza, em diferentes contextos. Contrariando o que a Gramática Tradicional (GT afirma a respeito dos verbos pronominais, a queda do clítico já vem sendo comprovada em algumas regiões brasileiras. Sendo assim, é importante verificarmos o uso desses pronomes por falantes de Fortaleza. Para tanto, basear-nos-emos na teoria variacionista, para analisarmos ocorrências retiradas do corpus PORCUFORT. Os resultados apontam para uma tendência ao desuso desses pronomes, inclusive, com alguns verbos considerados pronominais pela GT. Tais resultados mostram a validade de uma pesquisa que analise um corpus mais atual, já que os dados do PORCUFORT foram coletados na década de 80, para que possa ser verificado se atualmente o clítico tem sido mais frequentemente apagado ou utilizado.

STRUKTUR HISTOLOGI HATI MENCIT(Mus musculus L. SETELAH PEMBERIAN EKSTRAK DAUN EKOR NAGA (Rhapidhophora pinnata Schott

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Ni Komang Tia Pramesti

2017-09-01

Full Text Available ABSTRACT Rhapidhophora pinnata, Schott is a traditional medical plant that has been use remedy for treatment of hypertension, stroke. Aims of  this research is to determine the effect of Rhapidhophora pinnata Schott leaf extract toward  mouse (Mus musculus L liverhistological structure. This research used completely randomized  design with 28 female mice that were divide into 4 groups of  P0 (control received 0,9% NaCl, group P1, P2, and P3 received 50, 100 and 150 mg/kg bw respectively by oral administration. The treatment were given daily for 14 days. All of the mice were sacrificed by ether after 15 days. The liver were examined for their histopathological changes, namely fatty degeneration, hydropic degenaration and necrosis. Results were statistically analised by Kruskal-Wallis method. Treatment groups showed no significant differences with regard of liver histopatological changes, however hemorrhage, sinusoid congestion and inflamatory cell infiltration were found in liver.   Keyword : Rhapidhophora pinnata Schott, liver, mice

“The drawing is a pronunciation”: Paula Rego and Agustina Bessa-Luís

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Mariana Andrade da Cruz

2016-06-01

Full Text Available The aim of this text is to analise The Girls, book in which portuguese novelist Agustina Bessa-Luís concerns the compatriot painter Paula Rego's life and work. In spite of its biographic contours, with special focus on Rego's childhood and her relationship with Victor Willing, the text brings various reflexions about the nature of the artistic job itself. It is believed that, by reading the novel, it is possible to consider it not only as a critic appreciation report of Rego's artistic fortune, but also as a book which value indwells in itself. By introducing the painter's biography, Bessa-Luis finds connections with her own experience, and use them as starting points to weave a great number of metalinguistic reflexions, as well as thoughts about the relation between text and canvas. Considering that, it is intended to demonstrate how the book accuses an interartistical dialog, also demonstrating connecting points between Bessa-Luis writing and the images that permeates the novel.

Efeitos do caranguejo Pinnotheres ostreum em ostras Crassostrea rhizophorae

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Iracema Andrade Nascimento

1980-12-01

Full Text Available Some biological parameters of the oyster (Crassostrea rhizopharae, during the spawning and post-spawning periods, were analised in relation to the infestation by the pea crab (Pinnotheres ostreum The biological parameters considered were: size, total weight, wet and dry meat weight, and condition index. Utilizing the χ2 test these parameters and infestation by the pea crab were shown to to be associated. The incidence of pea crabs was higher during the spawning period than in the post-spawning period, reaching a maximum (20.3% infestation in oysters with a size of 6 to 7 cm. The values of the condition index and percent of meat (wet and dry weight for these oysters were significantly (P < 0.05 lower than for uninfested oysters. From these results there seems to be no doubt that the pea crab (V. ostreum injures the mangrove oysters which supports the conclusion that these crabs are true parasites for C. rhizophorae.

Nursing process according the model of self-care in a cardiac bedridden patient

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Aryele Rayana Antunes de Araújo

2014-06-01

Full Text Available Objetivo: Aplicar do processo de enfermagem segundo o Modelo do Autocuidado, proposto por Dorothea Orem. Métodos: Estudo de caso de caráter descritivo com abordagem qualitativa, que permite uma analise profunda do sujeito e da complexidade determinado pelo modelo proposto. Na análise dos dados observou-se a capacidade e a necessidade de autocuidado do sujeito a ser assistido. Resultados: Paciente mostrava-se interessada na dinâmica dos procedimentos pelos quais era submetida. No entanto, apresentava quatro déficits de autocuidado diagnosticados pelas pesquisadoras, tanto de acordo com o modelo estudado e a taxonomia NANDA-I, que deveriam ser supridos pela equipe de enfermagem. Conclusão: Percebeu-se que o Modelo do Autocuidado proposto por Orem é aplicável, de simples entendimento, e por isso, viável para a prática do cuidado cotidiano da equipe de enfermagem a um paciente cardiopata restrito ao leito.

Influência dos parâmetros de configuração do modelo CALMET sobre a simulação da circulação atmosférica na região metropolitana do Rio de Janeiro

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Luiz Claudio Gomes Pimentel

2014-12-01

Full Text Available O objetivo desse estudo é a analise dos efeitos dos parâmetros de configuração do modelo CALMET sobre a simulação da circulação atmosférica em superfície nas Bacias Aéreas I e III da Região Metropolitana do Rio de Janeiro (RMRJ. O estudo foi realizado para um período em que a RMRJ estava sob a atuação de um sistema de alta pressão, que não influenciou significativamente as circulações locais na região. A análise conjunta dos resultados indica que a melhor configuração para simulações do campo de vento na RMRJ com o sistema combinado de modelagem MM5/CALMET é obtida utilizando o valor de 10 km para o parâmetro TERRAD e Raio de Influência entre 7 e 10 km.

DISCURSOS QUE CIRCULAM NA CORREÇÃO DE UM QUESTIONÁRIO: SENTIDOS E SIGNIFICADOS

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Sheila Alves de Almeida

2012-01-01

Full Text Available This work analises the use of questionnaires in a primary Science classroom. We applied the questionnaires as a school genre, belonging to institutionalized practices among students and teachers which are carried out from tacit contracts that link both sides of the interaction. Based on the study of such genre, we have analysed three episodes concerning three different steps of the questionnaire correction. In the first instance, the roles played by the teacher and the students, as well as the social milieu from which they speak, hear and act are well defined, contrary to what happened in the second episode. As a product of a ceaseless movement, the discourse resists to a rigid systematization. In the last episode, we have identified that the words move on, in spite of the hierarchical oppressiveness. Therefore, from bakhtinian perspective, the fundamental question of this article is the discussion of the dialogical nature of the questionnaire.

Aplikasi ESDA untuk Studi Variabilitas Spasial Hujan Bulanan di Jawa Timur

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I Indarto

2011-12-01

Full Text Available This article expose the spatial variability of monthly-rainfall (MR in East Java region. Monthly rainfall data were collected from 943 pluviometres spread around the regions. Spatial statistics analysed by means of ESDA (Exploratory Spatial Data Analysis techniques available on Geostatistical Analyst extention of ArcGIS (9.3. Statistical tools exploited to analise the data include: (1 Histogram, (2 Voronoi Map, and (3 QQ-Plot. The result show that histogram and QQ-Plot of Monthly Rainfall data are leptocurtosis. Statistical value obtained from the analysis are: minimum = 54 mm/month, average = 155,5 mm/month, maximum = 386 mm/month, and median = 150 mm/month. Other statistical value summarised are: standard deviation = 44,2 ; skewness = 0,95; and curtosis = 5,09. Finally, monthly rainfall-maps are produced by interpolating the data using Inverse Distance Weighed (IDW interpolation method. The research demonstrate the capability and benefit of those statistical tool to describe detailed spatial variability of rainfall.

MANAGING THE COLD CHAIN: A CASE STUDY AT A SOUTH AFRICAN ICE CREAM COMPANY

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J. Grobler

2012-01-01

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ENGLISH ABSTRACT: This paper documents the results of a supply chain management (SCM case study conducted at Centurion Ice Cream and Sweets CC, a producer of ice cream in the greater Gauteng area. The current SCM environment was first analyzed before the distribution function was identified as a prime candidate for further analysis. A Monte Carlo simulation was subsequently performed to investigate the effect of different distribution scenarios. The paper concludes with an investigation into information technology (IT as the enabler for improved supply chain performance.

AFRIKAANSE OPSOMMING: Hierdie artikel dokumenteer die resultate van ‘n voorsieningskanaalgevallestudie uitgevoer by Centurion Ice Cream and Sweets CC, ‘n roomysvervaardiger in die Gauteng-area. Die voorsieningskanaal is eers ontleed voordat die distribusiefunksie geïdentifiseer is as ‘n kandidaat vir verdere analise. ‘n Monte Carlo-simulasie uitgevoer om die effek van verskillende distribusiescenarios te ondersoek. Die artikel sluit af met ‘n ondersoek na inligtingstegnologie as katalisator vir verbeterde voorsieningskanaalprestasie.

COLONIAL AMERICAN LITERATURE: MARVELOUS WONDERS AND THE MEDIEVAL TRADITION IN LUSO-BRAZILIAN HISTORIOGRAPHICAL CHRONICLES COLONIAL American Literature: WONDERS maravilhoso e da tradição medieval NO LUSO-BRASILEIRA historiográfica CHRONICLES

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Pedro Fonseca

1996-01-01

Full Text Available Este artigo apresenta uma analise interpretativa de certos aspectos do imaginário literário medieval e sua influência na formação tropológica das crônicas do Novo Mundo. A abordagem examina algumas das motivações estéticas e mentais da tradição medieval no discurso historiográfico luso-brasileiro colonial, principalmente em relação a alguns relatos de descobrimentos e ocupação inicial de terras brasileiras na América. This article presents an interpretative analysis of certain aspects of the medieval literary imaginary and its influence in the tropological formation of the New World chronicles. The approach examines some of the aesthetic and mental motivations of the medieval tradition in the colonial Luso-Brazilian historiographical discourse, principally in regards to some accounts of discoveries and initial occupation of Brazilian lands in America.  

Ciência na internet: Mapeamento da divulgação científica nos sites de nove Universidades Federais da região Nordeste do Brasil

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MORAES, Danilo de Almeida

2009-12-01

Full Text Available The present work investigate the characterics of the scientific publication on-line of nine Federal Universities from brazilian Northeast, that represents each state of this region: Maranhão (UFMA, Piauí (UFPI, Ceará (UFC, Rio Grande do Norte (UFRN, Paraíba (UFPB, Pernambuco (UFPE, Alagoas (UFAL, Sergipe (UFS and Bahia (UFBA. The objective of this work is analise, in each one of these sites, that works as suport for the dissemination of science, aspects like interactivity, updating and memory. Besides that, try to identify If these universities are considering the potential offered by the internet, when it tryes to close the society to the scientific knowledge, produced by proffessors and students. The research is based on systematic observation of each of the selected sites and in the opinion of researchers who study the science communication and the implications of the use of so-called new technologies in the field of communication.

DE LEGE FERENDA PROPOSAL FOR THE COMPLETION OF THE LEGAL FRAMEWORK REGARDING THE TEXTILE PRODUCTS, IN THE CONTEXT OF A SOCIAL RESPONSIBLE MANAGEMENT

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MUREȘAN (POȚINCU Laura

2016-05-01

Full Text Available In the case of this economic operator, manufacturing or trading textile products, the corporate social responsibility is a social must, and it consists of a set of objectives which must be implemented by the management of the economic operator in all departments. In order to understand the implications of a social responsibile management in the textile products domain, it is required to analise the juridical framework. Interesting is the choice in this area of the production and the marketing of textile products, to only adopt/use one regulation, not a directive or a legislative package consisting in a directive and a regulation. As a result of legal analysis performed, we support the maintenance of the use, as a legal instrument, of the European regulation type normative document, but we suggest the extension of the provisions of the European normative act and its transformation into a particular complex normative act, beyond the scope of the aspects concerning the labelling.

HISTORY, AUTHORITY, AND POWER: A Case of Religious Violence in Aceh

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Jajat Burhanudin

2014-06-01

Full Text Available This article discusses the way Islam transformed into an ideology that potentially used as justification for violence. By analising the case of the murder of Teungku Ayub, leader of a small circle for basic religious learning (pengajian in Bireun, Aceh, in 2012, the study reveals to the role of Islam as an ideology of mass movement to cleanse deviant tenet (aliran sesat among the Acehnese. This is because of two reasons. First, the term of the veranda of Mecca (serambi Mekkah remains considered as “holy word” in the Acehnese society today, which supports any Islamic agenda of purifying Aceh from aliran sesat. Secondly, the adoption of Islam into a formal body of state (Aceh province represented by the implementation of Islamic law (sharīʻah. Both reasons above strengthen ulama in Aceh to facilitate the mass movement in the name of religion as well as the rationale background of the murder of Teungku Ayub.

O DUALISMO DO SER ÓRFICO NA EPÍSTOLA DE PAULO AOS ROMANOS

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Roger Ribeiro da Silva

2010-01-01

Full Text Available Este trabalho consiste na comparação de fragmentos de textos encontrados na obra de Platão e na Epístola aos Romanos atribuída à Paulo. Retirados de inúmeros textos atribuídos a Platão, estes fragmentos tiveram confirmados indícios da teologia órfica pelo professor Alberto Bernabé Pajares. E ao aplicar a Metodologia de Analise do Discurso Teológico, desenvolvido especificamente para este trabalho, e comparado os resultados individuais, encontramos pontos de encontro entre as duas teologias, a Órfica e a Paulina, acentuando o que tange a crença no Dualismo do Ser. A problemática levantada neste trabalho se refere a como a representação1 da alma unida ao corpo, encontrada em escritos paulinistas, apresenta indícios de contatos com fundamentos órficos no berço do cristianismo.

O processo de regulamentação da ayahuasca no Brasil e na esfera internacional: desafios e implicações

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Beatriz Caiuby Labate

2012-09-01

Full Text Available DOI: 10.12957/periferia.2011.4054Este artigo propõe um resumo e uma analise daregulamentação da ayahuasca no Brasil, desde sua proibição em meados dos anos 80 ate a recente adoção da Resolução de 2010 do CONAD, que estabeleceu um conjunto de regras, normas e princípios éticos a serem aplicados aos usos religiosos e rituais da ayahuasca. O processo regulatório do Brasil e usado como ponto de partida para explorar o surgimento de temas regulatórios internacionais a medida que diversas nações respondem a expansão global de religiões de ayahuasca, como o Santo Daime e a Uniao do Vegetal. O texto analisa literatura acadêmica e documentos primários de caráter legislativo e judicial, assim como a posição de especialistas consultados.

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)

A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

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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.

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 ...

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 ...

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)

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

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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.

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.

Determinação de ferro (III em produtos farmacêuticos por titulação fotométrica = Determination of iron (III in pharmaceutical products by photometric titration

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Airton Vicente Pereira

2011-01-01

Full Text Available Este trabalho descreve a montagem de um sistema de titulacao fotometrica simples e de baixo custo para a determinacao de ferro (III em produtos farmaceuticos. O sistema de titulacao fotometrica foi construido utilizando-se a bomba peristaltica de um espectrofotometro convencional. O procedimento e baseado na titulacao de ferro (III com EDTA e acido salicilico como indicador. A absorcao do complexo ferro (III-acido salicilico foi monitorada espectrofotometricamente em 525 nm. O limite de quantificacao foi de 5 ƒÝg de ferro (III. O procedimento de titulacao fotometrica foi aplicado para a determinacao de ferro (III em amostras contendo sulfato ferroso e hidroxido ferrico polimaltosado. O procedimento mostrou sensibilidade, reprodutibilidade e precisao para a utilizacao em analise rotineira de ferro (III em produtos farmaceuticos.This paper describes a simple, precise and low-cost photometrictitration method for iron (III determination in pharmaceutical preparations. The photometric titration system was constructed using the peristaltic pump of a conventional spectrophotometer. The method is based on titration of iron (III with EDTA using salicylic acid as indicator. The absorption of the iron (III-salicylic acid complex wasmonitored spectrophotometrically at 525 nm. The limit of quantification was 5 ƒÝg of iron (III. The photometric titration procedure was applied for the determination of iron (III in samples of ferrous sulfate and ferric hydroxide polymaltose complex. The procedure showed sensibility, reproducibility and accuracy for use as a method for the routine analysis of iron (III in pharmaceutical formulations.

Folksonomia: a linguagem das tags

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Juliana de Assis

2013-04-01

Full Text Available http://dx.doi.org/10.5007/1518-2924.2013v18n36p85   A radicalização do potencial colaborativo da web atual aponta uma tendência de personalização da recuperação da informação através de ferramentas que exploram a linguagem natural na representação e no compartilhamento de conteúdos ao longo das redes sociais. Tal configuração sócio-técnica traz desafios aos profissionais da informação tanto para a descrição e compreensão dos fenômenos informacionais que ocorrem neste âmbito, quanto para a elaboração de produtos e serviços voltados para um usuário que se apresenta cada vez mais como sujeito informacional ao assumir um papel ativo diante da complexidade que caracteriza a organização da informação em contextos digitais. Este artigo apresenta conclusões de pesquisa, relacionadas às analises da linguagem utilizada em três ambientes colaborativos que utilizam a folksonomia (Social Tagging Systems. A partir de uma perspectiva fundamentada na Semiótica e na Análise de Redes Sociais, são identificadas e descritas as principais manifestações da linguagem gerada e compartilhada pelas redes sociais através destes ambientes.

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)

Traumatismos maxilofaciais como marcadores de violencia urbana: uma analise comparativa entre generos

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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.

Desigualdades sociais e tuberculose: analise segundo raca/cor, Mato Grosso do Sul

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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.

Antivirais incorporados no Brasil para hepatite B cronica: analise de custo-efetividade

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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.

Balanço comercial numa analise quantitativa Trade balance in quantitative analysis

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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.

Caracterização sensorial por analise descritiva quantitativa e analise tempo-intensidade de suco e de polpa de manga (Mangifera indica L.) adoçados com diferentes edulcorantes.

OpenAIRE

Daniela Cardoso Umbelino

2005-01-01

Resumo: O Brasil possui um grande potencial de produção de sucos de frutas tropicais, entre os quais destaca-se o suco de manga. Por outro lado, a preocupação com a saúde impulsionou a pesquisa e o desenvolvimento de alimentos de baixa caloria e adoçantes não calóricos. Os edulcorantes podem produzir características sensoriais indesejáveis, sendo necessário estudá-los, individualmente, no alimento ou bebida aos quais são adicionados. Este trabalho teve por objetivo estudar o comportamento do ...

Biaxial seismic behaviour of reinforced concrete columns =

Science.gov (United States)

Rodrigues, Hugo Filipe Pinheiro

A analise dos efeitos dos sismos mostra que a investigacao em engenharia sismica deve dar especial atencao a avaliacao da vulnerabilidade das construcoes existentes, frequentemente desprovidas de adequada resistencia sismica tal como acontece em edificios de betao armado (BA) de muitas cidades em paises do sul da Europa, entre os quais Portugal. Sendo os pilares elementos estruturais fundamentais na resistencia sismica dos edificios, deve ser dada especial atencao a sua resposta sob acoes ciclicas. Acresce que o sismo e um tipo de acao cujos efeitos nos edificios exige a consideracao de duas componentes horizontais, o que tem exigencias mais severas nos pilares comparativamente a acao unidirecional. Assim, esta tese centra-se na avaliacao da resposta estrutural de pilares de betao armado sujeitos a acoes ciclicas horizontais biaxiais, em tres linhas principais. Em primeiro lugar desenvolveu-se uma campanha de ensaios para o estudo do comportamento ciclico uniaxial e biaxial de pilares de betao armado com esforco axial constante. Para tal foram construidas quatro series de pilares retangulares de betao armado (24 no total) com diferentes caracteristicas geometricas e quantidades de armadura longitudinal, tendo os pilares sido ensaiados para diferentes historias de carga. Os resultados experimentais obtidos sao analisados e discutidos dando particular atencao a evolucao do dano, a degradacao de rigidez e resistencia com o aumento das exigencias de deformacao, a energia dissipada, ao amortecimento viscoso equivalente; por fim e proposto um indice de dano para pilares solicitados biaxialmente. De seguida foram aplicadas diferentes estrategias de modelacao nao-linear para a representacao do comportamento biaxial dos pilares ensaiados, considerando nao-linearidade distribuida ao longo dos elementos ou concentrada nas extremidades dos mesmos. Os resultados obtidos com as varias estrategias de modelacao demonstraram representar adequadamente a resposta em termos das curvas

Herança, sacralidade e poder: sobre as diferentes categorias do patrimônio histórico e cultural no Brasil

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Aline Sapiezinskas Krás Borges Canani

2005-06-01

Full Text Available O artigo examina o conceito de patrimônio presente nas atuais políticas públicas de preservação do patrimônio histórico, artístico e cultural, visando ampliar a apreensão deste. Trazendo exemplos do trabalho de campo realizado na Travessa dos Venezianos, em Porto Alegre, o meu propósito neste artigo é analisar como a atribuição de valor a determinados bens, objetos e processos produz novos significados nos diferentes contextos onde ocorre, focando especialmente na construção de significados do ponto de vista da herança, da sacralidade do patrimônio e da dimensão de poder envolvida no processo. Considerando as ressignificações resultantes do reconhecimento patrimonial, analiso as diferentes categorias percebidas pelos habitantes citadinos que estão envolvidos com o patrimônio, não de forma passiva, mas detendo a capacidade de construir novos significados e dar sentido ao mundo ao seu redor. Procuro sublinhar a dimensão simbólica que está presente nesse processo em que a propriedade adquire sentido e passa a ser considera como patrimônio ou herança familiar.This article deals with the concept of heritage present in the public policies of cultural, artistic and historical heritage preservation, aiming to widen the apprehension of the concept. Bringing examples from my fieldwork in Venezianos Lane, in Porto Alegre, my purpose in this article is to analise the attribution of values to specific buildings, objects or processes as a way to produce new meanings within the different contexts in which it occurs, observing specially the construction of signification from the point of view of familiar heritage, heritage objects seen as sacred properties and the dimension of power involved in such process. Considering the ressignifications which resulted from the heritage acknoledgement, I analise the different categories perceived by the city inhabitants who are involved with the heritage, not in a passive way, but owning the

Considerações sobre a tendência da tuberculose no Brasil

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Dina Czeresnia Costa

1985-09-01

Full Text Available Este trabalho analisa os vários aspectos que influenciam no padrão da mortalidade e morbidade da tuberculose: a variação nas condições de vida, os efeitos da quimioterapia e a dinâmica de transmissão da doença. Caracteriza os indicadores utilizados na medida da tuberculose que são construídos a partir de inquéritos de prevalência e dos dados de notificação. Os principais indicadores são: risco de infecção; mortalidade; coeficiente de incidência de meningite tuberculosa; coeficientes de incidência de casos de tuberculose, especialmente os pulmonares bacilíferos, etc. O trabalho analisa dados recentes de incidência de casos pulmonares bacilíferos nos estados do Pará e Rio Grande do Sul e mortalidade por tuberculose nas capitais do Pará, Rio Grande do Sul, Pernambuco e Rio de Janeiro, que revelam uma tendência à queda, ainda que em ritmo diferenciado. Discute-se a maneira que a crise econômica atual do país repercutiria no número de casos e mortes pela doença.This paper analises the various factors which affect the rate of mortality and illness from tuberculosis i.e. the variation in the quality of life of the people affected, the effects o f chemotherapy and the dynamics of the transmission of the disease. It describes the epidemiological indices used to measure the spread of tuberculosis. These indices are built up from inquiries of prevalence of the disease and the number of notified cases. The main indices are: the risk of infection, mortality, the coefficient of the incidence of tubercular meningitis, the coefficient of the incidence of cases of tuberculosis, especially smear positives, etc. The paper also analises recent data of incidence of cases of smear positives in the states of Pará and Rio Grande do Sul and the mortality rate from tuberculosis in the state capitals of Pará, Rio Grande do Sul, Pernambuco and Rio de Janeiro, which reveal a downward trend, thought at different rates. The nature of how the

Caring for terminal AIDS patients: The experiences of caregivers in a palliative care institution

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Magdalena (Dalena van Rooyen

2009-06-01

were developed in order to provide support for such caregivers. Opsomming Die fokus van hierdie navorsing was op die beleefde ervaringe van die versorgers wat met VIGS pasiënte werk, veral pasiënte wat sterf aan die siekte terwyl hulle in 'n formele inrigting is. 'n Kwalitatiewe, eksploratiewe, beskrywende en kontektuele navorsingsontwerp met 'n fenomenologiese benadering was gebruik. Dertien ongestruktueërde onderhoude, wat op 'n audioband opgeneem was is gehou met versorgers wat voltyds in 'n formele inrigting sorg vir pasiënte wat aan VIGS sterf werk. Tesch se metode van beskrywende analise was gebruik om die transkribeerde onderhoude te analiseer (in Cresswell 1994:115. Een sentrale tema het na vore gekom, naamlik dat versorgers tydens die uitvoering van hulle daaglikse pligte (in die werk 'n verskeidenheid uitdagings ondervind het as gevolg van hul pasiënte wat sterf van VIGS en vyf sub-temas is geformuleer deur verdure analise. Hierdie vyf sub-temas was: • Versorgers ervaar emosionele uitdagings tydings die versorging van pasiënte wat van VIGS sterf; • Versorgers ervaar n verskil in die dood en sterfte van volwassesnes teenoor die van kinders; • Versorgers ervaar die rasionaliseering van dood en sterfte verskillend; • Versorgers ervaar dat vertroue in God hulle krag gee om die dood en sterfte beter te hanteer; • Versorgers ervaar dat die versorging van pasiënte wat sterf of sterwend is vervullend is ten spyte van die hartseer van dood en sterfte. Die deelnemers ervaar die dood van hul pasiënte daagliks van 'n siekte wat ongetelde lyding vir hulself, die pasiënt en hul familie veroorsaak. Die versorgers wens dat hulle kon die angs en die pyn voorkom, sowel as die ombekwaamheid van die mediese beroep om huidiglik meer te kan doen om die siekte te genees. Hulle beskryf hul emosionele ervaringe wat die verskillende uitdagings wat hul ervaar as gevolg van hul betrokkenheid by die dood en afsterwe van hul pasiënte aan VIGS. Die inligting wat deur

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)

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.

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.

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)

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.

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)

Thermo-Hydraulic behaviour of dual-channel superconducting Cable-In-Conduit Conductors for ITER

International Nuclear Information System (INIS)

Renard, B.

2006-09-01

In an effort to optimise the cryogenics of large superconducting coils for fusion applications (ITER), dual channel Cable-In-Conduit Conductors (CICC) are designed with a central channel spiral to provide low hydraulic resistance and faster helium circulation. The qualitative and economic rationale of the conductor central channel is here justified to limit the superconductor temperature increase, but brings more complexity to the conductor cooling characteristics. The pressure drop of spirals is experimentally evaluated in nitrogen and water and an explicit hydraulic friction model is proposed. Temperatures in the cable must be quantified to guarantee superconductor margin during coil operation under heat disturbance and set adequate inlet temperature. Analytical one-dimensional thermal models, in steady state and in transient, allow to better understand the thermal coupling of CICC central and annular channels. The measurement of a heat transfer characteristic space and time constants provides cross-checking experimental estimations of the internal thermal homogenization. A simple explicit model of global inter-channel heat exchange coefficient is proposed. The risk of thermosyphon between the two channels is considered since vertical portions of fusion coils are subject to gravity. The new hydraulic model, heat exchange model and gravitational risk ratio allow the thermohydraulic improvement of CICC central spirals. (author)

Natural convection in closed vertical cylinders with particular reference to gas cooled reactor standpipes

International Nuclear Information System (INIS)

Spence, I.D.

1975-09-01

The access to the core for fuel assemblies and control rods of the Advanced Gas Cooled Reactor is through the top cap by means of standpipes. The standpipe is essentially a cylindrical, vertical tube with cooled side wall, closed upper end and an orifice at the lower end which is exposed to the hot core fluid. This creates confined natural convection flow in the empty standpipe and this is the subject of this thesis. The investigation is carried out using analytical and experimental methods. For the analytical work, solution of laminar and turbulent flow is attempted using finite-difference computer techniques. The laminar flow performance is evaluated using two different finite-difference procedures, and the results are compared to each other and to existing analytical and experimental results for the open thermosyphon with cool inflow and hot sidewall, i.e. the complementary problem to the present one. For turbulent flow a two equation turbulence model is employed which provides transport equations for the kinetic energy of turbulence and its dissipation rate. The experimental rig is a full scale replica of the Advanced Gas Cooled Reactor control rod mechanism standpipe. Carbon dioxide and helium are used as the working fluids for the series of tests. (author)