WorldWideScience

Sample records for improves cycling performance

  1. High-intensity cycle interval training improves cycling and running performance in triathletes.

    Science.gov (United States)

    Etxebarria, Naroa; Anson, Judith M; Pyne, David B; Ferguson, Richard A

    2014-01-01

    Effective cycle training for triathlon is a challenge for coaches. We compared the effects of two variants of cycle high-intensity interval training (HIT) on triathlon-specific cycling and running. Fourteen moderately-trained male triathletes ([Formula: see text]O2peak 58.7 ± 8.1 mL kg(-1) min(-1); mean ± SD) completed on separate occasions a maximal incremental test ([Formula: see text]O2peak and maximal aerobic power), 16 × 20 s cycle sprints and a 1-h triathlon-specific cycle followed immediately by a 5 km run time trial. Participants were then pair-matched and assigned randomly to either a long high-intensity interval training (LONG) (6-8 × 5 min efforts) or short high-intensity interval training (SHORT) (9-11 × 10, 20 and 40 s efforts) HIT cycle training intervention. Six training sessions were completed over 3 weeks before participants repeated the baseline testing. Both groups had an ∼7% increase in [Formula: see text]O2peak (SHORT 7.3%, ±4.6%; mean, ±90% confidence limits; LONG 7.5%, ±1.7%). There was a moderate improvement in mean power for both the SHORT (10.3%, ±4.4%) and LONG (10.7%, ±6.8%) groups during the last eight 20-s sprints. There was a small to moderate decrease in heart rate, blood lactate and perceived exertion in both groups during the 1-h triathlon-specific cycling but only the LONG group had a substantial decrease in the subsequent 5-km run time (64, ±59 s). Moderately-trained triathletes should use both short and long high-intensity intervals to improve cycling physiology and performance. Longer 5-min intervals on the bike are more likely to benefit 5 km running performance.

  2. Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Combined cycle performance

    DEFF Research Database (Denmark)

    Haglind, Fredrik

    2011-01-01

    The part-load performance of combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry gas turbines on the part-load efficiency for combined...... cycles used for ship propulsion. Moreover, the paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within combined cycle power plants. Two different gas turbine configurations are studied, a two-shaft aero......-derivative configuration and a single-shaft industrial configuration. The results suggest that by the use of variable geometry gas turbines, the combined cycle part-load performance can be improved. In order to minimise the voyage fuel consumption, a combined cycle featuring two-shaft gas turbines with VAN control...

  3. Performance improvement: an active life cycle product management

    Science.gov (United States)

    Cucchiella, Federica; Gastaldi, Massimo; Lenny Koh, S. C.

    2010-03-01

    The management of the supply chain has gained importance in many manufacturing firms. Operational flexibility can be considered a crucial weapon to increase competitiveness in a turbulent marketplace. It reflects the ability of a firm to properly and rapidly respond to a variable and dynamic environment. For the firm operating in a fashion sector, the management of the supply chain is even more complex because the product life cycle is shorter than that of the firm operating in a non-fashion sector. The increase of firm flexibility level can be reached through the application of the real option theory inside the firm network. In fact, real option may increase the project value by allowing managers to more efficiently direct the production. The real option application usually analysed in literature does not take into account that the demands of products are well-defined by the product life cycle. Working on a fashion sector, the life cycle pattern is even more relevant because of an expected demand that grows according to a constant rate that does not capture the demand dynamics of the underlying fashion goods. Thus, the primary research objective of this article is to develop a model useful for the management of investments in a supply chain operating in a fashion sector where the system complexity is increased by the low level of unpredictability and stability that is proper of the mood phenomenon. Moreover, unlike the traditional model, a real option framework is presented here that considers fashion product characterised by uncertain stages of the production cycle.

  4. 'Virtual' central business office: how UMMS improved revenue cycle performance.

    Science.gov (United States)

    Henciak, Bill; Fontaine, Christine; Fields, Keith; Parks, Stacy

    2010-06-01

    Based on its experience with implementing a virtual central business office, UMMS recommends the following steps to ensure the success of such an initiative: Define the process flow for the organization's day-today revenue cycle operations prior to implementation. Then select best practices and milestones for managing accounts. Identify any possible technology issues that could arise during implementation prior to go live. Hold a midproject debriefing with staff. Develop an organizational chart that details who is responsible for handling issues that arise during implementation and afterward.

  5. Improvement of performance operation and cycle efficiency of Al Anbar combined power plant

    International Nuclear Information System (INIS)

    Jabbar, Mohammed Q.

    2014-01-01

    The present work will be focusing on available solution which can serve to increase total efficiency of Al Anbar combined cycle power plant - CCPP, and thus to improve the operation performance as much as possible in order to decrease hydrocarbon, CO2, NOx emissions to environment.The simulation and calculations were performed by program software cycle-tempo software. The results were compared with basic design of Alanbar power plant after making modernization with solar tower receiver system-STRS, which represented a heat source in preheat process for a compressor air. Key Words: CCPP, STRS, Solar potential energy, fuel consumption, hydrocarbon emission

  6. Improvements in Cycling but Not Handcycling 10 km Time Trial Performance in Habitual Caffeine Users.

    Science.gov (United States)

    Graham-Paulson, Terri; Perret, Claudio; Goosey-Tolfrey, Victoria

    2016-06-25

    Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake ( V · peak) 42.9 (7.3)/27.6 (5.1) mL∙kg∙min(-1), 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific V · peak (preload) followed by a 10 km TT following the ingestion of 4 mg∙kg(-1) caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants' training status.

  7. Competitor presence reduces internal attentional focus and improves 16.1km cycling time trial performance.

    Science.gov (United States)

    Williams, Emily L; Jones, Hollie S; Andy Sparks, S; Marchant, David C; Midgley, Adrian W; Mc Naughton, Lars R

    2015-07-01

    Whilst the presence of a competitor has been found to improve performance, the mechanisms influencing the change in selected work rates during direct competition have been suggested but not specifically assessed. The aim was to investigate the physiological and psychological influences of a visual avatar competitor during a 16.1-km cycling time trial performance, using trained, competitive cyclists. Randomised cross-over design. Fifteen male cyclists completed four 16.1km cycling time trials on a cycle ergometer, performing two with a visual display of themselves as a simulated avatar (FAM and SELF), one with no visual display (DO), and one with themselves and an opponent as simulated avatars (COMP). Participants were informed the competitive avatar was a similar ability cyclist but it was actually a representation of their fastest previous performance. Increased performance times were evident during COMP (27.8±2.0min) compared to SELF (28.7±1.9min) and DO (28.4±2.3min). Greater power output, speed and heart rate were apparent during COMP trial than SELF (pperformance. Competitive cyclists performed significantly faster during a 16.1-km competitive trial than when performing maximally, without a competitor. The improvement in performance was elicited due to a greater external distraction, deterring perceived exertion. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  8. Caffeinated nitric oxide-releasing lozenge improves cycling time trial performance.

    Science.gov (United States)

    Lee, J; Kim, H T; Solares, G J; Kim, K; Ding, Z; Ivy, J L

    2015-02-01

    Boosting nitric oxide production during exercise by various means has been found to improve exercise performance. We investigated the effects of a nitric oxide releasing lozenge with added caffeine (70 mg) on oxygen consumption during steady-state exercise and cycling time trial performance using a double-blinded randomized, crossover experimental design. 15 moderately trained cyclists (7 females and 8 males) were randomly assigned to ingest the caffeinated nitric oxide lozenge or placebo 5 min before exercise. Oxygen consumption and blood lactate were assessed at rest and at 50%, 65% and 75% maximal oxygen consumption. Exercise performance was assessed by time to complete a simulated 20.15 km cycling time-trial course. No significant treatment effects for oxygen consumption or blood lactate at rest or during steady-state exercise were observed. However, time-trial performance was improved by 2.1% (p<0.01) when participants consumed the nitric oxide lozenge (2,424±69 s) compared to placebo (2,476±78 s) and without a significant difference in rating of perceived exertion. These results suggest that acute supplementation with a caffeinated nitric oxide releasing lozenge may be a practical and effective means of improving aerobic exercise performance. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Cooling tower performance improvements for a cycling PC-fired unit

    International Nuclear Information System (INIS)

    Keckritz, M.; Thelen, A.

    1997-01-01

    The inevitable deregulation of the electric utility industry has caused many electric utility companies to look closely at their existing assets and predict what role these units will play in the future. Reducing a unit's production cost is the best way to prepare for the deregulated market but this benefit often comes with an associated capital expenditure. Spending capital dollars today can pose a quandary for an investor-owned utility committed to maintaining low consumer rates. The dilemma is: How does a utility improve its competitiveness position today while ensuring that the shareholders are getting a fair return on their investment when any fuel savings are passed through to the consumer? Illinois Power (IP) has been aggressively looking to improve their current competitive position while facing the current regulatory challenges. Studies have been commissioned to identify the most attractive cost reduction opportunities available. One study identified that improving the performance of the Unit 6 cooling tower at the Havana Station would be a very economically attractive option. This paper addresses the economics of refurbishing a cooling tower for a cycling pulverized-coal (PC) unit to provide a competitive advantage leading into the deregulated electricity market

  10. Measuring and Comparing Descend in Elite Race Cycling with a Perspective on Real-Time Feedback for Improving Individual Performance

    OpenAIRE

    Reijne, M.M.; Bregman, D.J.J.; Schwab, A.L.; Espinosa, Hugo G.; Rowlands, David R.; Shepherd, Jonathan; Thiel, David V.

    2018-01-01

    Descend technique and performance vary among elite racing cyclists and it is not clear what slower riders should do to improve their performance. An observation study was performed of the descending technique of members of a World Tour cycling team and the technique of each member was compared with the fastest descender amongst them. The obtained data gives us guidelines for rider specific feedback in order to improve his performance. The bicycles were equipped with a system that could measur...

  11. Measuring and Comparing Descend in Elite Race Cycling with a Perspective on Real-Time Feedback for Improving Individual Performance

    NARCIS (Netherlands)

    Reijne, M.M.; Bregman, D.J.J.; Schwab, A.L.; Espinosa, Hugo G.; Rowlands, David R.; Shepherd, Jonathan; Thiel, David V.

    2018-01-01

    Descend technique and performance vary among elite racing cyclists and it is not clear what slower riders should do to improve their performance. An observation study was performed of the descending technique of members of a World Tour cycling team and the technique of each member was compared with

  12. Fuel performance and operation experience of WWER-440 fuel in improved fuel cycle

    International Nuclear Information System (INIS)

    Gagarinski, A.; Proselkov, V.; Semchenkov, Yu.

    2007-01-01

    The paper summarizes WWER-440 second-generation fuel operation experience in improved fuel cycles using the example of Kola NPP units 3 and 4. Basic parameters of fuel assemblies, fuel rods and uranium-gadolinium fuel rods, as well as the principal neutronic parameters and burn-up achieved in fuel assemblies are presented. The paper also contains some data concerning the activity of coolant during operation (Authors)

  13. Near Zero Energy House (NZEH) Design Optimization to Improve Life Cycle Cost Performance Using Genetic Algorithm

    Science.gov (United States)

    Latief, Y.; Berawi, M. A.; Koesalamwardi, A. B.; Supriadi, L. S. R.

    2018-03-01

    Near Zero Energy House (NZEH) is a housing building that provides energy efficiency by using renewable energy technologies and passive house design. Currently, the costs for NZEH are quite expensive due to the high costs of the equipment and materials for solar panel, insulation, fenestration and other renewable energy technology. Therefore, a study to obtain the optimum design of a NZEH is necessary. The aim of the optimum design is achieving an economical life cycle cost performance of the NZEH. One of the optimization methods that could be utilized is Genetic Algorithm. It provides the method to obtain the optimum design based on the combinations of NZEH variable designs. This paper discusses the study to identify the optimum design of a NZEH that provides an optimum life cycle cost performance using Genetic Algorithm. In this study, an experiment through extensive design simulations of a one-level house model was conducted. As a result, the study provide the optimum design from combinations of NZEH variable designs, which are building orientation, window to wall ratio, and glazing types that would maximize the energy generated by photovoltaic panel. Hence, the design would support an optimum life cycle cost performance of the house.

  14. Analysis of different image-based biofeedback models for improving cycling performances

    Science.gov (United States)

    Bibbo, D.; Conforto, S.; Bernabucci, I.; Carli, M.; Schmid, M.; D'Alessio, T.

    2012-03-01

    Sport practice can take advantage from the quantitative assessment of task execution, which is strictly connected to the implementation of optimized training procedures. To this aim, it is interesting to explore the effectiveness of biofeedback training techniques. This implies a complete chain for information extraction containing instrumented devices, processing algorithms and graphical user interfaces (GUIs) to extract valuable information (i.e. kinematics, dynamics, and electrophysiology) to be presented in real-time to the athlete. In cycling, performance indexes displayed in a simple and perceivable way can help the cyclist optimize the pedaling. To this purpose, in this study four different GUIs have been designed and used in order to understand if and how a graphical biofeedback can influence the cycling performance. In particular, information related to the mechanical efficiency of pedaling is represented in each of the designed interfaces and then displayed to the user. This index is real-time calculated on the basis of the force signals exerted on the pedals during cycling. Instrumented pedals for bikes, already designed and implemented in our laboratory, have been used to measure those force components. A group of subjects underwent an experimental protocol and pedaled with (the interfaces have been used in a randomized order) and without graphical biofeedback. Preliminary results show how the effective perception of the biofeedback influences the motor performance.

  15. Mouth rinsing improves cycling endurance performance during Ramadan fasting in a hot humid environment.

    Science.gov (United States)

    Che Muhamed, Ahmad Munir; Mohamed, Nazirah Gulam; Ismail, Norjana; Aziz, Abdul Rashid; Singh, Rabindarjeet

    2014-04-01

    This study examined the effect of mouth rinsing during endurance cycling in a hot humid environment (32 °C and 75% relative humidity) on athletes in the Ramadan fasted state. Nine trained adolescent male cyclists completed 3 trials that consisted of a carbohydrate mouth-rinse (CMR), a placebo mouth-rinse (PMR), and a no-rinse (NOR) trial during the last 2 weeks of Ramadan. Each trial consisted of a preloading cycle at 65% peak rate of oxygen consumption for 30 min followed by a 10-km time trial (TT10 km) under hot humid condition. During the CMR and PMR trials, each cyclist rinsed his mouth with 25 mL of the solution for 5 s before expectorating the solution pre-exercise, after 5, 15, and 25 min of the preloading cycle, and 15 s prior to the start of TT10 km. Time to complete the TT10 km was significantly faster in the CMR and PMR trials compared with the NOR trial (12.9 ± 1.7 and 12.6 ± 1.7 vs. 16.8 ± 1.6 min, respectively; p benefits compared with a no-rinse condition on TT10 km performance in acute Ramadan fasted subjects during endurance cycling in a heat stress environment.

  16. Improvement of CaO-based sorbent performance for CO{sub 2} looping cycles

    Energy Technology Data Exchange (ETDEWEB)

    Vasilije Manovic; Edward J. Anthony [CANMET Energy Technology Centre-Ottawa, Ottawa, ON (Canada)

    2009-07-01

    This paper presents research on CO{sub 2} capture by lime-based looping cycles. This is a new and promising technology that may help in mitigation of global warming and climate change caused primarily by the use of fossil fuels. The intensity of the anticipated changes urgently requires solutions such as the developing technologies for CO{sub 2} capture, especially those based on CaO looping cycles. This technology is at the pilot plant demonstration stage and there are still significant challenges that require solutions. The technology is based on a dual fluidized bed reactor which contains a carbonator - a unit for CO{sub 2} capture, and a calciner - a unit for CaO regeneration. The major technology components are well known from other technologies and easily applicable. However, even though CaO is a very good candidate as a solid CO{sub 2} carrier, its performance in a practical system still has significant limitations. Thus, research on CaO performance is critical and this paper discusses some of the more important problems and potential solutions that are being examined at CETC-O. To date, the most promising methods were reactivation of spent sorbent by steam, thermal pretreatment of sorbent, and doping, most likely with Al{sub 2}O{sub 3}. The combination of these methods, including pelletization, should provide us with enhanced sorbent performance. 75 refs., 19 figs.

  17. Measuring and Comparing Descend in Elite Race Cycling with a Perspective on Real-Time Feedback for Improving Individual Performance

    Directory of Open Access Journals (Sweden)

    M. M. Reijne

    2018-02-01

    Full Text Available Descend technique and performance vary among elite racing cyclists and it is not clear what slower riders should do to improve their performance. An observation study was performed of the descending technique of members of a World Tour cycling team and the technique of each member was compared with the fastest descender amongst them. The obtained data gives us guidelines for rider specific feedback in order to improve his performance. The bicycles were equipped with a system that could measure: velocity, cadence, pedal power, position, steer angle, 3D orientation, rotational speeds and linear accelerations of the rear frame and brake force front and rear. From our observation study, the brake point and apex position turned out to be distinctive indicators of a fast cornering technique in a descent for a tight, hairpin corner. These two indicators can be used as feedback for a slower rider to improve his descend performance.

  18. Mouth Rinsing with Maltodextrin Solutions Fails to Improve Time Trial Endurance Cycling Performance in Recreational Athletes

    Directory of Open Access Journals (Sweden)

    Tuğba Nilay Kulaksız

    2016-05-01

    Full Text Available The carbohydrate (CHO concentration of a mouth rinsing solution might influence the CHO sensing receptors in the mouth, with consequent activation of brain regions involved in reward, motivation and regulation of motor activity. The purpose of the present study was to examine the effects of maltodextrin mouth rinsing with different concentrations (3%, 6% and 12% after an overnight fast on a 20 km cycling time trial performance. Nine recreationally active, healthy males (age: 24 ± 2 years; V ˙ O 2 m a x : 47 ± 5 mL·kg−1·min−1 participated in this study. A double-blind, placebo-controlled randomized study was conducted. Participants mouth-rinsed every 2.5 km for 5 s. Maltodextrin mouth rinse with concentrations of 3%, 6% or 12% did not change time to complete the time trial and power output compared to placebo (p > 0.05. Time trial completion times were 40.2 ± 4.0, 40.1 ± 3.9, 40.1 ± 4.4, and 39.3 ± 4.2 min and power output 205 ± 22, 206 ± 25, 210 ± 24, and 205 ± 23 W for placebo, 3%, 6%, and 12% maltodextrin conditions, respectively. Heart rate, lactate, glucose, and rating of perceived exertion did not differ between trials (p > 0.05. In conclusion, mouth rinsing with different maltodextrin concentrations after an overnight fast did not affect the physiological responses and performance during a 20 km cycling time trial in recreationally active males.

  19. Potential performance improvement using a reacting gas (nitrogin tetroxide) as the working fluid in a closed Brayton cycle

    Science.gov (United States)

    Stochl, R. J.

    1979-01-01

    The results of an analysis to estimate the performance that could be obtained by using a chemically reacting gas (nitrogen tetroxide) as the working fluid in a closed Brayton cycle are presented. Compared with data for helium as the working fluid, these results indicate efficiency improvements from 4 to 90 percent, depending on turbine inlet temperature, pressures, and gas residence time in heat transfer equipment.

  20. Water Chemistry Control Technology to Improve the Performance of Nuclear Power Plants for Extended Fuel Cycles

    International Nuclear Information System (INIS)

    Maeng, W. Y.; Na, J. W.; Lee, E. H.

    2010-07-01

    Ο To Develop the technology to manage the problems of AOA and radiation, corrosion as long term PWR operation. Ο To Establish the advanced water chemical operating systems. - Development of the proper water chemistry guidelines for long term PWR operation. AOA(Axial Offest Anomaly) has been reported in many PWR plants in the world, including Korea, especially in the plants of higher burn-up and longer cycle operation or power up-rate. A test loop has been designed and made by KAERI, in order to investigate and mitigate AOA problems in Korea. This project included the study of hydrodynamic simulation and the modeling about AOA. The analysis of radioactive crud was performed to investigate of NPPs primary water chemical effect on AOA and to reduce the radioactive dose rate. The high temperature measurement system was developed to on-line monitor of water chemistry in nuclear power plants. The effects of various environmental factors such as temperature, pressure, and flow rate on YSZ-based pH electrode were evaluated for ensuring the accuracy of high-temperature pH measurement. The inhibition technology for fouling and SCC of SG tube was evaluated to establish the water chemistry technology of corrosion control of nuclear system. The high temperature and high pressure crevice chemistry analysis test loop was manufactured to develop the water chemistry technology of crevice chemistry control

  1. Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Gas turbine performance

    DEFF Research Database (Denmark)

    Haglind, Fredrik

    2010-01-01

    The part-load performance of gas and steam turbine combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry on the gas turbine part...... of various components within gas turbines. Two different gas turbine configurations are studied, a two-shaft aero-derivative configuration and a single-shaft industrial configuration. When both gas turbine configurations are running in part-load using fuel flow control, the results indicate better part......-load performance for the two-shaft gas turbine. Reducing the load this way is accompanied by a much larger decrease in exhaust gas temperature for the single-shaft gas turbine than for the two-shaft configuration. As used here, the results suggest that variable geometry generally deteriorates the gas turbine part...

  2. Coinciding exercise with peak serum caffeine does not improve cycling performance.

    Science.gov (United States)

    Skinner, Tina L; Jenkins, David G; Taaffe, Dennis R; Leveritt, Michael D; Coombes, Jeff S

    2013-01-01

    To investigate whether coinciding peak serum caffeine concentration with the onset of exercise enhances subsequent endurance performance. Randomised, double-blind, crossover. In this randomised, placebo-controlled, double-blind crossover study, 14 male trained cyclists and triathletes (age 31±5year, body mass 75.4±5.7 kg, VO₂max 69.5±6.1 mL kg⁻¹ min⁻¹ and peak power output 417±35W, mean±SD) consumed 6 mg kg(-1) caffeine or a placebo either 1h (C(1h)) prior to completing a 40 km time trial or when the start of exercise coincided with individual peak serum caffeine concentrations (C(peak)). C(peak) was determined from a separate 'caffeine profiling' session that involved monitoring caffeine concentrations in the blood every 30 min over a 4h period. Following caffeine ingestion, peak serum caffeine occurred 120 min in 12 participants and 150 min in 2 participants. Time to complete the 40 km time trial was significantly faster (2.0%; p=0.002) in C(1h) compared to placebo. No statistically significant improvement in performance was noted in the C(peak) trial versus placebo (1.1%; p=0.240). Whilst no differences in metabolic markers were found between C(peak) and placebo conditions, plasma concentrations of glucose (p=0.005), norepinephrine and epinephrine (p≤0.002) were higher in the C(1h) trial 6 min post-exercise versus placebo. In contrast to coinciding peak serum caffeine concentration with exercise onset, caffeine consumed 60 min prior to exercise resulted in significant improvements in 40 km time trial performance. The ergogenic effect of caffeine was not found to be related to peak caffeine concentration in the blood at the onset of endurance exercise. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. Improvements in Cycling Time Trial Performance Are Not Sustained Following the Acute Provision of Challenging and Deceptive Feedback

    Directory of Open Access Journals (Sweden)

    Hollie S Jones

    2016-09-01

    Full Text Available TThe provision of performance-related feedback during exercise is acknowledged as an influential external cue used to inform pacing decisions. The provision of this feedback in a challenging or deceptive context allows research to explore how feedback can be used to improve performance and influence perceptual responses. However, the effects of deception on both acute and residual responses have yet to be explored, despite potential application for performance enhancement. Therefore, this study investigated the effects of challenging and deceptive feedback on perceptual responses and performance in self-paced cycling time trials (TT and explored whether changes in performance are sustained in a subsequent TT following the disclosure of the deception.Seventeen trained male cyclists were assigned to either an accurate or deceptive feedback group and performed four 16.1 km cycling TTs; 1 and 2 ride-alone baseline TTs where a fastest baseline (FBL performance was identified, 3 a TT against a virtual avatar representing 102% of their FBL performance (PACER, and 4 a subsequent ride-alone TT (SUB. The deception group, however, were initially informed that the avatar accurately represented their FBL, but prior to SUB were correctly informed of the nature of the avatar. Affect, self-efficacy and RPE were measured every quartile. Both groups performed PACER faster than FBL and SUB (p < 0.05 and experienced lower affect (p = 0.016, lower self-efficacy (p = 0.011, and higher RPE (p < 0.001 in PACER than FBL. No significant differences were found between FBL and SUB for any variable. The presence of the pacer rather than the manipulation of performance beliefs acutely facilitates TT performance and perceptual responses. Revealing that athletes’ performance beliefs were falsely negative due to deceptive feedback provision has no effect on subsequent perceptions or performance. A single experiential exposure may not be sufficient to produce meaningful

  4. Improving broadcast performance of radio duty-cycled Internet-of-Things devices

    NARCIS (Netherlands)

    Guclu, S.S.; Özcelebi, T.; Lukkien, J.J.

    2017-01-01

    Asynchronous Radio Duty Cycling (ARDC) protocols can make embedded networked devices more energy efficient by keeping their radio off most of the time without a need for synchronization between devices. Some ARDC protocols can operate under 6LoWPAN adaptation layer in order to enable the vision of

  5. Predictive control strategy of a gas turbine for improvement of combined cycle power plant dynamic performance and efficiency.

    Science.gov (United States)

    Mohamed, Omar; Wang, Jihong; Khalil, Ashraf; Limhabrash, Marwan

    2016-01-01

    This paper presents a novel strategy for implementing model predictive control (MPC) to a large gas turbine power plant as a part of our research progress in order to improve plant thermal efficiency and load-frequency control performance. A generalized state space model for a large gas turbine covering the whole steady operational range is designed according to subspace identification method with closed loop data as input to the identification algorithm. Then the model is used in developing a MPC and integrated into the plant existing control strategy. The strategy principle is based on feeding the reference signals of the pilot valve, natural gas valve, and the compressor pressure ratio controller with the optimized decisions given by the MPC instead of direct application of the control signals. If the set points for the compressor controller and turbine valves are sent in a timely manner, there will be more kinetic energy in the plant to release faster responses on the output and the overall system efficiency is improved. Simulation results have illustrated the feasibility of the proposed application that has achieved significant improvement in the frequency variations and load following capability which are also translated to be improvements in the overall combined cycle thermal efficiency of around 1.1 % compared to the existing one.

  6. Improvement of high voltage cycling performance and thermal stability of lithium-ion cells by use of a thiophene additive

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ki-Soo; Sun, Yang-Kook; Kim, Dong-Won [Department of Chemical Engineering, Hanyang University, Seungdong-gu, Seoul 133-791 (Korea); Noh, Jaegeun [Department of Chemistry, Hanyang University, Seungdong-gu, Seoul 133-791 (Korea); Song, Kwang Soup [Advanced Medical Device Center, Korea Electrotechnology, Research Institute, Ansan, Gyeonggi-do 426-170 (Korea)

    2009-10-15

    This study demonstrates that the addition of thiophene improves the cycle life of lithium-ion cells at high voltage. Electrochemical impedance spectroscopy results suggest that addition of thiophene significantly suppresses the increase of the charge transfer resistance that occurs during cycling up to high voltage. Differential scanning calorimetric studies showed that the thermal stability of fully charged LiCoO{sub 2} cathode was also enhanced in the presence of thiophene. (author)

  7. Precooling With Crushed Ice: As Effective as Heat Acclimation at Improving Cycling Time-Trial Performance in the Heat.

    Science.gov (United States)

    Zimmermann, Matthew; Landers, Grant; Wallman, Karen; Kent, Georgina

    2018-02-01

    This study compared the effects of precooling (ice ingestion) and heat-acclimation training on cycling time-trial (CTT) performance in the heat. Fifteen male cyclists/triathletes completed two 800-kJ CTTs in the heat, with a 12-d training program in between. Initially, all participants consumed 7 g/kg of water (22°C) in 30 min before completing an 800-kJ CTT in hot, humid conditions (pre-CTT) (35°C, 50% relative humidity [RH]). Participants were then split into 2 groups, with the precooling group (n = 7) training in thermoneutral conditions and then undergoing precooling with ice ingestion (7 g/kg, 1°C) prior to the final CTT (post-CTT) and the heat-acclimation group (n = 8) training in hot conditions (35°C, 50% RH) and consuming water (7 g/kg) prior to post-CTT. After training in both conditions, improvement in CTT time was deemed a likely positive benefit (precooling -166 ± 133 s, heat acclimation -105 ± 62 s), with this result being similar between conditions (d = 0.22, -0.68-1.08 90% confidence interval [CI]). Core temperature for post-CTT was lower in precooling than in heat acclimation from 20 min into the precooling period until the 100-kJ mark of the CTT (d > 0.98). Sweat onset occurred later in precooling (250 ± 100 s) than in heat acclimation (180 ± 80 s) for post-CTT (d = 0.65, -0.30-1.50 90% CI). Thermal sensation was lower at the end of the precooling period prior to post-CTT for the precooling trial than with heat acclimation (d = 1.24, 0.90-1.58 90% CI). Precooling with ice ingestion offers an alternative method of improving endurance-cycling performance in hot conditions if heat acclimation cannot be attained.

  8. Improving the performances of gas turbines operated on natural gas in combined cycle power plants with application of mathematical models

    International Nuclear Information System (INIS)

    Dimkovski, Sasho

    2014-01-01

    The greater energy demand by today society sets a number of new challenges in the energy sector. The climate extremes impose new modes of operation of the power plants, with high flexibility in production. Combined cycle co generative power plants are the latest trend in the energy sector. Their high prevalence is due to the great efficiency and the good environmental characteristics. The main work horse in these cogeneration plants is the gas turbine, which power production and efficiency strongly depends on the external climate conditions. In warmer periods when there is increased demand for electricity, the power production from the gas turbines significantly declines. Because of the high electricity demand from the grid and reduced power production from the gas turbines at the same time, the need for application of appropriate technology for preserving the performances and power of the gas turbines arises. This master thesis explores different methods to improve the power in gas turbines by cooling the air on the compressor inlet, analyzing their applicability and effectiveness in order to choose the optimal method for power augmentation for the climatic conditions in the city Skopje. The master thesis gives detailed analysis of the weather in Skopje and the time frame in which the chosen method is applicable. At the end in the master thesis, the economic feasibility of the given method for power augmentation is clearly calculated, using a model of a power plant and calculating the resulting amount of gained energy, the amount of the initial investment, the cost for maintenance and operation of the equipment. By these calculations the period for initial return of investment is obtained. As an added benefit the positive environmental impacts of the applied technology for inlet air cooling is analyzed. (author)

  9. Embroidered Copper Microwire Current Collector for Improved Cycling Performance of Silicon Anodes in Lithium-Ion Batteries.

    Science.gov (United States)

    Breitung, Ben; Aguiló-Aguayo, Noemí; Bechtold, Thomas; Hahn, Horst; Janek, Jürgen; Brezesinski, Torsten

    2017-10-12

    Si holds great promise as an alloying anode material for Li-ion batteries with improved energy density because of its high theoretical specific capacity and favorable operation voltage range. However, the large volume expansion of Si during electrochemical reaction with Li and the associated adverse effects strongly limit its prospect for application. Here, we report on the use of three-dimensional instead of flat current collectors for high-capacity Si anodes in an attempt to mitigate the loss of electrical contact of active electrode regions as a result of structural disintegration with cycling. The current collectors were produced by technical embroidery and consist of interconnected Cu wires of diameter <150 µm. In comparison to Si/Li cells using a conventional Cu foil current collector, the embroidered microwire network-based cells show much enhanced capacity and reversibility due to a higher degree of tolerance to cycling.

  10. Much improved capacity and cycling performance of LiVMoO6 cathode for lithium ion batteries

    International Nuclear Information System (INIS)

    Zhou Liqun; Liang Yongguang; Hu Ling; Han Xiaoyan; Yi Zonghui; Sun Jutang; Yang Shuijin

    2008-01-01

    Spherical LiVMoO 6 nanocrystals as cathode for lithium ion batteries were synthesized using a solvothermal reaction method. Powder XRD data indicate that a single phase LiVMoO 6 with brannerite-type structure is obtained at 550 deg. C by the thermal treatment of the precursor for 6 h. SEM image shows that the particles are composed of loosely stacked spheres with a uniform particle size about 40 nm. The electrode properties of LiVMoO 6 have also been studied by galvanostatic cycling and ac impedance spectroscopy. LiVMoO 6 nanospheres delivered 172 mAh g -1 capacity in the initial discharge process with a reversible capacity retention of 94.4% after 100 cycles in the range of 3.6-1.80 V versus metallic Li at a current density of 100 mA g -1 . The microstructure developed in the electrodes give evidence that the particle size and morphological properties play an important role in the much improved capacity and cycling stability at large currents than ordinary samples

  11. Highly conductive bridges between graphite spheres to improve the cycle performance of a graphite anode in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongyu [IM and T Ltd., Advanced Research Center, Saga University, Yoga-machi 1341, Saga 840-0047 (Japan); Umeno, Tatsuo; Mizuma, Koutarou [Research Center, Mitsui Mining Co. Ltd., Hibiki-machi 1-3, Wakamatsu-ku, Kitakyushu 808-0021 (Japan); Yoshio, Masaki [Advanced Research Center, Saga University, Yoga-machi 1341, Saga 840-0047 (Japan)

    2008-01-10

    Spherical carbon-coated natural graphite (SCCNG) is a promising anode material for lithium-ion batteries, but the smooth surface of graphite spheres is difficult to wet with an aqueous binder solution, and lacks electrical contacts. As a result, the cycle performance of such a graphite anode material is not satisfactory. An effective method has been introduced to tightly connect adjacent SCCNG particles by a highly conductive binder, viz. acetylene black bridges. The effect of the conductive bridges on the cyclability of SCCNG electrode has been investigated. (author)

  12. Dual-shell hollow polyaniline/sulfur-core/polyaniline composites improving the capacity and cycle performance of lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    An, Yanling; Wei, Pan; Fan, Meiqiang, E-mail: fanmeiqiang@126.com; Chen, Da; Chen, Haichao; Ju, QiangJian; Tian, Guanglei; Shu, Kangying

    2016-07-01

    Highlights: • A dual core-shell hPANI/S/PANI composite was prepared in situ synthesis. • Cycle performance of the hPANI/S/PANI composite was enhanced. • The improvement was due to fine sulfur particles wrapped by two PANI films. • Some positive effects were elaborated. - Abstract: In this study, a dual-shell hollow polyaniline/sulfur-core/polyaniline (hPANI/S/PANI) composite was prepared by successively depositing PANI, S, and PANI on the surface of a template silicon sphere. The electrochemical properties of this composite were evaluated using a lithium plate as an anode in lithium/sulfur cells. The hPANI/S/PANI composite showed a discharge capacity of 572.2 mAh g{sup −1} after 214 cycles at 0.1 C, and the Coulombic efficiency was above 87% in the whole charge/discharge cycle. The improved cycle property of the hPANI/S/PANI composite can be ascribed to the fine sulfur particles homogeneously deposited on the PANI surface and sprawled inside the two PANI layers during the charge/discharge cycle. This behavior stabilized the nanostructure of sulfur and enhanced its conductivity.

  13. Improvement of the cycling performance of LiCoO2 with assistance of cross-linked PAN for lithium ion batteries

    International Nuclear Information System (INIS)

    Yang, Xinhe; Shen, Lanyao; Wu, Bin; Zuo, Zicheng; Mu, Daobin; Wu, Borong; Zhou, Henghui

    2015-01-01

    Highlights: • Cross-linked PAN coating was prepared without damaging the surface of LiCoO 2 . • The coating layer owns good electronic conductivity and mechanical strength. • The cross-linked PAN coating layer is more sufficient than Al 2 O 3 coating. • It shows much improved cyclability than that of bare and Al 2 O 3 coated LiCoO 2 . - Abstract: LiCoO 2 has been widely used in lithium ion batteries for digital electronic products. However, the limited cycling performance under high cut-off voltage hinders its commercial application. Many metal oxides and/or phosphorus coating have been reported to improve the cycling performance of LiCoO 2 . In this paper, we report on cross-linked PAN coated LiCoO 2 composite as a cathode material for lithium ion batteries. The coating layer was obtained by intermolecular crosslinking of PAN polymer chain by heat treatment at high temperature in air. The air heating process avoids the possible damage arising from the carbon thermal reduction to the surface structure of LiCoO 2 . Electrochemical test indicates that the LiCoO 2 with the cross-linked PAN coating layer shows much improved cycle performance compared with that of bare and Al 2 O 3 coated LiCoO 2 . These findings might also open new avenues to explore polymer coating for other cathode materials of lithium ion batteries

  14. Enamel coated steel reinforcement for improved durability and life-cycle performance of concrete structures: microstructure, corrosion, and deterioration

    Science.gov (United States)

    Tang, Fujian

    This study is aimed (a) to statistically characterize the corrosion-induced deterioration process of reinforced concrete structures (concrete cracking, steel mass loss, and rebar-concrete bond degradation), and (b) to develop and apply three types of enamel-coated steel bars for improved corrosion resistance of the structures. Commercially available pure enamel, mixed enamel with 50% calcium silicate, and double enamel with an inner layer of pure enamel and an outer layer of mixed enamel were considered as various steel coatings. Electrochemical tests were respectively conducted on steel plates, smooth bars embedded in concrete, and deformed bars with/without concrete cover in 3.5 wt.% NaCl or saturated Ca(OH)2 solution. The effects of enamel microstructure, coating thickness variation, potential damage, mortar protection, and corrosion environment on corrosion resistance of the steel members were investigated. Extensive test results indicated that corrosion-induced concrete cracking can be divided into four stages that gradually become less correlated with corrosion process over time. The coefficient of variation of crack width increases with the increasing level of corrosion. Corrosion changed the cross section area instead of mechanical properties of steel bars. The bond-slip behavior between the corroded bars and concrete depends on the corrosion level and distribution of corrosion pits. Although it can improve the chemical bond with concrete and steel, the mixed enamel coating is the least corrosion resistant. The double enamel coating provides the most consistent corrosion performance and is thus recommended to coat reinforcing steel bars for concrete structures applied in corrosive environments. Corrosion pits in enamel-coated bars are limited around damage locations.

  15. Improvement in high-voltage and high rate cycling performance of nickel-rich layered cathode materials via facile chemical vapor deposition with methane

    International Nuclear Information System (INIS)

    Hyuk Son, In; Park, Kwangjin; Hwan Park, Jong

    2017-01-01

    Nickel-rich layered-oxide materials are considered promising candidates for application as cathode material in high-energy lithium ion batteries. However, their cycling performance at high voltages and rate conditions require further improvement for the purpose of commercialization. Here, we report on the facile surface modification of nickel-rich layered oxide by chemical vapor deposition with methane which yields a conductive and protective artificial solid electrolyte interphase layer consisting of amorphous carbon, alkyl lithium carbonate, and lithium carbonate. We examine the mechanism of the protective layer formation and structural deformation of the nickel-rich layered oxide during chemical vapor deposition with methane. Via optimizing the reaction conditions, we improve the electrical conductivity as well as the interfacial stability of the nickel-rich layered oxide without inducing structural deformation. The surface-modified nickel-rich layered oxide exhibits an improved performance due to the resulting enhanced rate capability, high initial efficiency, and long cycle life at high voltage (>4.5 V).

  16. Improving fleet performance

    International Nuclear Information System (INIS)

    Ramjist, S.

    2015-01-01

    Use Fleet Initiatives to Improve Overall Fleet Performance . Tightly Integrated with Business Planning (Cause & Effect) . Leverage Strength of Broader Organization - Converge on Standard Business Practices . Ancillary Benefit of Improved Agility.

  17. Improving fleet performance

    Energy Technology Data Exchange (ETDEWEB)

    Ramjist, S. [Ontario Power Generation, Toronto, ON (Canada)

    2015-07-01

    Use Fleet Initiatives to Improve Overall Fleet Performance . Tightly Integrated with Business Planning (Cause & Effect) . Leverage Strength of Broader Organization - Converge on Standard Business Practices . Ancillary Benefit of Improved Agility.

  18. No improvement in race performance by naps in male ultra-endurance cyclists in a 600-km ultra-cycling race.

    Science.gov (United States)

    Knechtle, Beat; Wirth, Andrea; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2012-04-30

    Ultra-endurance performance is of increasing popularity. We investigated the associations between anthropometry, training and support during racing, with race performance in 67 male recreational ultra-endurance cyclists participating in the 'Swiss Cycling Marathon' over 600 kilometres, an official qualifier for the cycling ultra-marathon 'Paris-Brest-Paris'. The 54 finishers showed no differences in anthropometry and did not train differently compared to the 13 non-finishers. During the race, the finishers were significantly more frequently racing alone than being followed by a support crew. After bivariate analysis, percent body fat (r = 0.43), the cycling distance per training unit (r = -0.36), the duration per training unit (r = -0.31) and the sleep time during the race (r = 0.50) were related to overall race time. The 23 non-sleepers in the finisher group completed the race within (mean and IQR) 1,567 (1,453-1,606) min, highly significantly faster than the 31 sleepers with 1,934 (1,615-2,033) min (P = 0.0003). No variable of support during the race was associated with race time. After multivariate analysis, percent body fat (P = 0.026) and duration per training unit (P = 0.005) remained predictor variables for race time. To summarize, for a successful finish in a cycling ultra-marathon over 600 kilometres such as the 'Swiss Cycling Marathon', percent body fat and duration per training unit were related to race time whereas equipment and support during the race showed no association. Athletes with naps were highly significantly slower than athletes without naps.

  19. Improving Teaching through Collaborative Reflective Teaching Cycles

    Science.gov (United States)

    Murray, Eileen

    2015-01-01

    Reflection and collaboration are two activities teachers can use to change and improve their practice. However, finding the time and space to do so can be challenging. The collaborative reflective teaching cycle is a structured activity teachers can use to engage in reflection and collaboration. This article describes how a seventh grade teaching…

  20. MCNP Progress & Performance Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bull, Jeffrey S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-14

    Twenty-eight slides give information about the work of the US DOE/NNSA Nuclear Criticality Safety Program on MCNP6 under the following headings: MCNP6.1.1 Release, with ENDF/B-VII.1; Verification/Validation; User Support & Training; Performance Improvements; and Work in Progress. Whisper methodology will be incorporated into the code, and run speed should be increased.

  1. Analysis of Refrigeration Cycle Performance with an Ejector

    Directory of Open Access Journals (Sweden)

    Wani J. R.

    2016-01-01

    Full Text Available A conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses during the expansion process. A refrigeration cycle with ejector is a promising modification to improve the performance of conventional refrigeration cycle. The ejector is used to recover some of the available work so that the compressor suction pressure increases. To investigate the enhancement a model with R134a refrigerant was developed. To solve the set of equations and simulate the cycle performance a subroutine was written on engineering equation solver (EES environment. At specific conditions, the refrigerant properties are obtained from EES. At the design conditions the ejector refrigeration cycle achieved 5.141 COP compared to 4.609 COP of the conventional refrigeration cycle. This means that ejector refrigeration cycle offers better COP with 10.35% improvement compared to conventional refrigeration cycle. Parametric analysis of ejector refrigeration cycle indicated that COP was influenced significantly by evaporator and condenser temperatures, entrainment ratio and diffuser efficiency.

  2. Containment performance improvement program

    International Nuclear Information System (INIS)

    Beckner, W.; Mitchell, J.; Soffer, L.; Chow, E.; Lane, J.; Ridgely, J.

    1990-01-01

    The Containment Performance Improvement (CPI) program has been one of the main elements in the US Nuclear Regulatory Commission's (NRC's) integrated approach to closure of severe accident issues for US nuclear power plants. During the course of the program, results from various probabilistic risk assessment (PRA) studies and from severe accident research programs for the five US containment types have been examined to identify significant containment challenges and to evaluate potential improvements. The five containment types considered are: the boiling water reactor (BMR) Mark I containment, the BWR Mark II containment, the BWR Mark III containment, the pressurized water reactor (PWR) ice condenser containment, and the PWR dry containments (including both subatmospheric and large subtypes). The focus of the CPI program has been containment performance and accident mitigation, however, insights are also being obtained in the areas of accident prevention and accident management

  3. A New, Highly Improved Two-Cycle Engine

    Science.gov (United States)

    Wiesen, Bernard

    2008-01-01

    The figure presents a cross-sectional view of a supercharged, variable-compression, two-cycle, internal-combustion engine that offers significant advantages over prior such engines. The improvements are embodied in a combination of design changes that contribute synergistically to improvements in performance and economy. Although the combination of design changes and the principles underlying them are complex, one of the main effects of the changes on the overall engine design is reduced (relative to prior two-cycle designs) mechanical complexity, which translates directly to reduced manufacturing cost and increased reliability. Other benefits include increases in the efficiency of both scavenging and supercharging. The improvements retain the simplicity and other advantages of two-cycle engines while affording increases in volumetric efficiency and performance across a wide range of operating conditions that, heretofore have been accessible to four-cycle engines but not to conventionally scavenged two-cycle ones, thereby increasing the range of usefulness of the two-cycle engine into all areas now dominated by the four-cycle engine. The design changes and benefits are too numerous to describe here in detail, but it is possible to summarize the major improvements: Reciprocating Shuttle Inlet Valve The entire reciprocating shuttle inlet valve and its operating gear is constructed as a single member. The shuttle valve is actuated in a lost-motion arrangement in which, at the ends of its stroke, projections on the shuttle valve come to rest against abutments at the ends of grooves in a piston skirt. This shuttle-valve design obviates the customary complex valve mechanism, actuated from an engine crankshaft or camshaft, yet it is effective with every type of two-cycle engine, from small high-speed single cylinder model engines, to large low-speed multiple cylinder engines.

  4. Quality Improvement Cycles that Reduced Waiting Times at ...

    African Journals Online (AJOL)

    It was decided to undertake quality improvement (QI) cycles to analyse and improve the situation, using waiting time as a measure of improvement. Methods: A QI team was chosen to conduct two QI cycles. The allocated time for QI cycle 1 was from May to August 2006 and for QI cycle 2 from September to December 2006.

  5. Effect of irreversible processes on the thermodynamic performance of open-cycle desiccant cooling cycles

    International Nuclear Information System (INIS)

    La, Dong; Li, Yong; Dai, Yanjun; Ge, Tianshu; Wang, Ruzhu

    2013-01-01

    Highlights: ► Effects of irreversible processes on the performance of desiccant cooling cycle are identified. ► The exergy destructions involved are classified by the properties of the individual processes. ► Appropriate indexes for thermodynamic evaluation are proposed based on thermodynamic analyses. - Abstract: Thermodynamic analyses of desiccant cooling cycle usually focus on the overall cycle performance in previous study. In this paper, the effects of the individual irreversible processes in each component on thermodynamic performance are analyzed in detail. The objective of this paper is to reveal the elemental features of the individual components, and to show their effects on the thermodynamic performance of the whole cycle in a fundamental way. Appropriate indexes for thermodynamic evaluation are derived based on the first and second law analyses. A generalized model independent of the connection of components is developed. The results indicate that as the effectiveness of the desiccant wheel increases, the cycle performance is increased principally due to the significant reduction in exergy carried out by exhaust air. The corresponding exergy destruction coefficient of the cycle with moderate performance desiccant wheel is decreased greatly to 3.9%, which is more than 50% lower than that of the cycle with low performance desiccant wheel. The effect of the heat source is similar. As the temperature of the heat source increases from 60 °C to 90 °C, the percentage of exergy destruction raised by exhaust air increases sharply from 5.3% to 21.8%. High heat exchanger effectiveness improves the cycle performance mainly by lowering the irreversibility of the heat exchanger, using less regeneration heat and pre-cooling the process air effectively

  6. Sodium bicarbonate improves 4 km time trial cycling performance when individualised to time to peak blood bicarbonate in trained male cyclists.

    Science.gov (United States)

    Gough, Lewis A; Deb, Sanjoy K; Sparks, S Andy; McNaughton, Lars R

    2018-08-01

    The aim of this study was to investigate the effects of sodium bicarbonate (NaHCO 3 ) on 4 km cycling time trial (TT) performance when individualised to a predetermined time to peak blood bicarbonate (HCO 3 - ). Eleven male trained cyclists volunteered for this study (height 1.82 ± 0.80 m, body mass (BM) 86.4 ± 12.9 kg, age 32 ± 9 years, peak power output (PPO) 382 ± 22 W). Two trials were initially conducted to identify time to peak HCO 3 - following both 0.2 g . kg -1 BM (SBC2) and 0.3 g . kg -1 BM (SBC3) NaHCO 3 . Thereafter, on three separate occasions using a randomised, double-blind, crossover design, participants completed a 4 km TT following ingestion of either SBC2, SBC3, or a taste-matched placebo (PLA) containing 0.07 g . kg -1 BM sodium chloride (NaCl) at the predetermined individual time to peak HCO 3 - . Both SBC2 (-8.3 ± 3.5 s; p < 0.001, d = 0.64) and SBC3 (-8.6 ± 5.4 s; p = 0.003, d = 0.66) reduced the time to complete the 4 km TT, with no difference between SBC conditions (mean difference = 0.2 ± 0.2 s; p = 0.87, d = 0.02). These findings suggest trained cyclists may benefit from individualising NaHCO 3 ingestion to time to peak HCO 3 - to enhance 4 km TT performance.

  7. Performance investigation of advanced adsorption desalination cycle with condenser-evaporator heat recovery scheme

    KAUST Repository

    Thu, Kyaw; Kim, Youngdeuk; Myat, Aung; Chakraborty, Anutosh; Ng, K. C.

    2013-01-01

    Energy or heat recovery schemes are keys for the performance improvement of any heat-activated cycles such as the absorption and adsorption cycles. We present two innovative heat recovery schemes between the condensing and evaporating units

  8. A reengineering success story: process improvement in emergency department x-ray cycle time, leading to breakthrough performance in the ED ambulatory care (Fast Track) process.

    Science.gov (United States)

    Espinosa, J A; Treiber, P M; Kosnik, L

    1997-01-01

    This article describes the journey of a multidisciplinary reengineering team, which worked to reduce a critical, high-leverage process in an emergency department setting. The process selected was emergency department radiology services. This process was selected on a rational basis. The team knew tht 60 percent of our emergency department patients were truly ambulatory, and that most could be seen in a "fast track" process as part of our emergency department's core mission. However, we knew from customer satisfaction data, that patients would like to be "in and out" of emergency department Fast Track in less than an hour. Over half of our Fast Track patients require x-rays. For most, this was their sole reason for seeking emergency care. Our state, at the start of the project, included an average x-ray cycle time of over 60 minutes. The associated Fast-Track cycle time was over 90 minutes median. It was clear to the emergency department leadership, as well as to members of the Fast-Track management team, that a cycle time of 30 minutes or less for x-ray service was needed as a necessary condition to an hour or less Fast Track cycle time. It was also felt that a more rapid x-ray cycle time would allow for more rapid turn over of ED rooms, leading to a virtual greater capacity to the ED. It was hoped that this would lead to a reduction in the time from arrival to treatment by the emergency physician for all patients.

  9. Improving construction performance

    International Nuclear Information System (INIS)

    1990-03-01

    Design for Constructability's overall purpose was to identify and address changes in the nuclear industry to restore nuclear energy as an attractive option for new generating capacity. As the centerpiece of project control, a comprehensive, stable schedule should organize the project logically to accomplish the project's objectives. A good schedule will: integrate the project team; serve as a communications tool to all members of the project team; and provide a means to monitor and measure project performance

  10. Development of web based performance analysis program for nuclear power plant turbine cycle

    International Nuclear Information System (INIS)

    Park, Hoon; Yu, Seung Kyu; Kim, Seong Kun; Ji, Moon Hak; Choi, Kwang Hee; Hong, Seong Ryeol

    2002-01-01

    Performance improvement of turbine cycle affects economic operation of nuclear power plant. We developed performance analysis system for nuclear power plant turbine cycle. The system is based on PTC (Performance Test Code), that is estimation standard of nuclear power plant performance. The system is developed using Java Web-Start and JSP(Java Server Page)

  11. Energetic and exergetic Improvement of geothermal single flash cycle

    Directory of Open Access Journals (Sweden)

    Navid Nazari

    2016-08-01

    Full Text Available This paper presents a detailed analysis of a new method for improving energetic and exergetic efficiencies of single flash cycle. The thermodynamic process of the new method consists of extracting a fraction of hot wellhead geothermal brine for the purpose of superheating saturated steam entering the turbine. Computer programming scripts were developed and optimized based on mathematical proposed models for the different components of the systems. The operating parameters such as separator temperature, geofluid wellhead enthalpy and geothermal source temperature are varied to investigate their effects on both net power output and turbine exhaust quality of the systems. Also, full exergy assessment was performed for the new design. The results of separator temperature optimization revealed that specific net power output of the new design can be boosted up to 8% and turbine exhaust quality can be diminished up to 50% as compared to common single flash cycle. In addition, for wells with higher discharge enthalpy, superheating process improve specific net power output even up to 10%. Finally, it was observed that the overall system exergy efficiency was approximately raised 3%. Article History: Received January 5th 2016; Received in revised form June 25th 2016; Accepted July 3rd 2016; Available online How to Cite This Article: Nazari, N. and Porkhial, S. (2016. Energetic and Exergetic Improvement of Geothermal Single Flash Cycle. Int. Journal of Renewable Energy Development, 5(2,129-138. http://dx.doi.org/10.14710/ijred.5.2.129-138 

  12. Technological tendencies for the improvement of the performance of combined cycle power stations; Tendencias tecnologicas para el mejoramiento del desempeno de centrales de cilco combinado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez P, Marino; Garduno R, Raul; Chavez T, Rafael [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In this article are dealt some the aspects that have turned the combined cycle generating power stations (CCGPS) into the dominant way for the electrical generation in the world. In the first part it is presented the plan of expansion of the national electrical generation and similar information that the U.S.A. has for the CCGPS, which will give an idea of the importance and the impact that has this technology at the moment. The basic characteristics that are necessary to specify in order to satisfy the environmental and operation requirements, and the available technologies to increase the global efficiency of the CCGPS are also exposed. Finally it describes the evolution of the technology of control for CCGPS developed in the Gerencia de Control e Instrumentacion (GCI), as well as the capacities available to support the electrical sector in this technological discipline. [Spanish] En este articulo se tratan algunos de los aspectos que han convertido a las centrales de generacion de ciclo combinado (CGCC) en el modo dominante para la generacion electrica en el mundo. En la primera parte se presenta el plan de expansion de la generacion electrica nacional e informacion similar que los EE.UU. tienen para las CGCC, lo que dara una idea de la importancia y del impacto que tiene actualmente esta tecnologia. Se exponen tambien las caracteristicas principales que es necesario especificar a fin de satisfacer los requerimientos ambientales y de operacion, y las tecnologias disponibles para incrementar la eficiencia global de las CGCC. Finalmente se describe la evolucion de la tecnologia de control para CGCC desarrollada en la Gerencia de Control e Instrumentacion (GCI), asi como las capacidades disponibles para apoyar al sector electrico en esta disciplina tecnologica.

  13. Performance concerns for high duty fuel cycle

    International Nuclear Information System (INIS)

    Esposito, V.J.; Gutierrez, J.E.

    1999-01-01

    One of the goals of the nuclear industry is to achieve economic performance such that nuclear power plants are competitive in a de-regulated market. The manner in which nuclear fuel is designed and operated lies at the heart of economic viability. In this sense reliability, operating flexibility and low costs are the three major requirements of the NPP today. The translation of these three requirements to the design is part of our work. The challenge today is to produce a fuel design which will operate with long operating cycles, high discharge burnup, power up-rating and while still maintaining all design and safety margins. European Fuel Group (EFG) understands that to achieve the required performance high duty/energy fuel designs are needed. The concerns for high duty design includes, among other items, core design methods, advanced Safety Analysis methodologies, performance models, advanced material and operational strategies. The operational aspects require the trade-off and evaluation of various parameters including coolant chemistry control, material corrosion, boiling duty, boron level impacts, etc. In this environment MAEF is the design that EFG is now offering based on ZIRLO alloy and a robust skeleton. This new design is able to achieve 70 GWd/tU and Lead Test Programs are being executed to demonstrate this capability. A number of performance issues which have been a concern with current designs have been resolved such as cladding corrosion and incomplete RCCA insertion (IRI). As the core duty becomes more aggressive other new issues need to be addressed such as Axial Offset Anomaly. These new issues are being addressed by combination of the new design in concert with advanced methodologies to meet the demanding needs of NPP. The ability and strategy to meet high duty core requirements, flexibility of operation and maintain acceptable balance of all technical issues is the discussion in this paper. (authors)

  14. Nuclear Fuel Cycle Options Catalog: FY16 Improvements and Additions

    Energy Technology Data Exchange (ETDEWEB)

    Price, Laura L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barela, Amanda Crystal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schetnan, Richard Reed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walkow, Walter M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-08-31

    The United States Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Program sponsors nuclear fuel cycle research and development. As part of its Fuel Cycle Options campaign, the DOE has established the Nuclear Fuel Cycle Options Catalog. The catalog is intended for use by the Fuel Cycle Technologies Program in planning its research and development activities and disseminating information regarding nuclear energy to interested parties. The purpose of this report is to document the improvements and additions that have been made to the Nuclear Fuel Cycle Options Catalog in the 2016 fiscal year.

  15. Nuclear Fuel Cycle Options Catalog FY15 Improvements and Additions.

    Energy Technology Data Exchange (ETDEWEB)

    Price, Laura L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Barela, Amanda Crystal [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Schetnan, Richard Reed [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Walkow, Walter M. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    The United States Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Program sponsors nuclear fuel cycle research and development. As part of its Fuel Cycle Options campaign, the DOE has established the Nuclear Fuel Cycle Options Catalog. The catalog is intended for use by the Fuel Cycle Technologies Program in planning its research and development activities and disseminating information regarding nuclear energy to interested parties. The purpose of this report is to document the improvements and additions that have been made to the Nuclear Fuel Cycle Options Catalog in the 2015 fiscal year.

  16. Tune-control improvements on the rapid-cycling synchrotron

    International Nuclear Information System (INIS)

    Potts, C.; Faber, M.; Gunderson, G.; Knott, M.; Voss, D.

    1981-01-01

    The as-built lattice of the Rapid-Cycling Synchrotron (RCS) had two sets of correction sextupoles and two sets of quadrupoles energized by dc power supplies to control the tune and the tune tilt. With this method of powering these magnets, adjustment of tune conditions during the accelerating cycle as needed was not possible. A set of dynamically programmable power supplies has been built and operated to provide the required chromaticity adjustment. The short accelerating time (16.7 ms) of the RCS and the inductance of the magnets dictated large transistor amplifier power supplies. The required time resolution and waveform flexibility indicated the desirability of computer control. Both the amplifiers and controls are described, along with resulting improvements in the beam performance. A set of octupole magnets and programmable power supplies with similar dynamic qualities have been constructed and installed to control the anticipated high-intensity transverse instability. This system will be operational in the spring of 1981

  17. Designer and Constructor Practices to Ensure Life Cycle Performance

    National Research Council Canada - National Science Library

    Shelton, Joelle

    1998-01-01

    .... Many of these attempts focus on reducing costs and improving functionality, such as life cycle cost analysis and value engineering, while others, such as design-build, focus on specific phases of the life cycle...

  18. Course Development Cycle Time: A Framework for Continuous Process Improvement.

    Science.gov (United States)

    Lake, Erinn

    2003-01-01

    Details Edinboro University's efforts to reduce the extended cycle time required to develop new courses and programs. Describes a collaborative process improvement framework, illustrated data findings, the team's recommendations for improvement, and the outcomes of those recommendations. (EV)

  19. Can training improve human performance

    International Nuclear Information System (INIS)

    Waylett, W.J. Jr.

    1986-01-01

    The nuclear industry has made a significant commitment to improve training through the implementation of performance-based training programs. Senior management expects that human performance improvement will result from this significant resource allocation. The author examines this hypothesis and discusses other issues that may interfere with enhancing human performance through training. The integration of quality improvement concepts to support training is also discussed by the author, who was a pioneer facilitator during the development of Florida Power and Light Company's Quality Improvement Program. Critical success factors are proposed based on the author's experience as a plant manager, training manager and quality facilitator

  20. Improved performance of the industry

    International Nuclear Information System (INIS)

    Jeffrey, R.

    1994-01-01

    The remarkable improvements in the performance of AGR stations is illustrated. The underlying reasons for this improvement are discussed, emphasizing both the operational performance factors which have led to higher sustained output and the managerial and cultural changes which have focused attention at all levels on the need to be competitive. It is concluded that the UK nuclear industry has become world class with more improvements to come, an asset to the UK. (Author)

  1. Performance assessment of simple and modified cycle turboshaft gas turbines

    Directory of Open Access Journals (Sweden)

    Barinyima Nkoi

    2013-06-01

    Full Text Available This paper focuses on investigations encompassing comparative assessment of gas turbine cycle options. More specifically, investigation was carried out of technical performance of turboshaft engine cycles based on existing simple cycle (SC and its projected modified cycles for civil helicopter application. Technically, thermal efficiency, specific fuel consumption, and power output are of paramount importance to the overall performance of gas turbine engines. In course of carrying out this research, turbomatch software established at Cranfield University based on gas turbine theory was applied to conduct simulation of a simple cycle (baseline two-spool helicopter turboshaft engine model with free power turbine. Similarly, some modified gas turbine cycle configurations incorporating unconventional components, such as engine cycle with low pressure compressor (LPC zero-staged, recuperated engine cycle, and intercooled/recuperated (ICR engine cycle, were also simulated. In doing so, design point (DP and off-design point (OD performances of the engine models were established. The percentage changes in performance parameters of the modified cycle engines over the simple cycle were evaluated and it was found that to a large extent, the modified engine cycles with unconventional components exhibit better performances in terms of thermal efficiency and specific fuel consumption than the traditional simple cycle engine. This research made use of public domain open source references.

  2. Performance evaluation of an ejector subcooled vapor-compression refrigeration cycle

    International Nuclear Information System (INIS)

    Xing, Meibo; Yan, Gang; Yu, Jianlin

    2015-01-01

    Highlights: • An ejector subcooled vapor-compression refrigeration cycle is proposed. • The performance of the cycle with ejector subcooling is evaluated theoretically. • Increase in refrigeration capacity can be achieved by the ejector subcooled cycle. • The new cycle exhibits higher COP compared to the basic single-stage cycle. • Performance of the new cycle depends on the operation pressures of the ejector. - Abstract: In this study, a novel vapor-compression refrigeration cycle with mechanical subcooling using an ejector is proposed to improve the performance of a conventional single-stage vapor-compression refrigeration cycle. In the theoretical study, a mathematical model is developed to predict the performance of the cycle by using R404A and R290, and then compared with that of the conventional refrigeration cycle. The simulation results show that the performance of the ejector subcooled cycle is better than that of the conventional cycle. When the evaporator temperature ranges from −40 to −10 °C and the condenser temperature is 45 °C, the novel cycle displays volumetric refrigeration capacity improvements of 11.7% with R404A and 7.2% with R290. And the novel cycle achieves COP improvements of 9.5% with R404A and 7.0% with R290. In addition, the improvement of the COP and cooling capacity of this novel cycle largely depends on the operation pressures of the ejector. The potential practical advantages offered by the cycle may be worth further attention in future studies

  3. Performance characteristics of a quantum Diesel refrigeration cycle

    International Nuclear Information System (INIS)

    He Jizhou; Wang Hao; Liu Sanqiu

    2009-01-01

    The Diesel refrigeration cycle using an ideal quantum gas as the working substance is called quantum Diesel refrigeration cycle, which is different from Carnot, Ericsson, Brayton, Otto and Stirling refrigeration cycles. For ideal quantum gases, a corrected equation of state, which considers the quantum behavior of gas particles, is used instead of the classical one. The purpose of this paper is to investigate the effect of quantum gas as the working substance on the performance of a quantum Diesel refrigeration cycle. It is found that coefficients of performance of the cycle are not affected by the quantum degeneracy of the working substance, which is the same as that of the classical Diesel refrigeration cycle. However, the refrigeration load is different from those of the classical Diesel refrigeration cycle. Lastly, the influence of the quantum degeneracy on the performance characteristics of the quantum Diesel refrigeration cycle operated in different temperature regions is discussed

  4. Performance improvement: the organization's quest.

    Science.gov (United States)

    McKinley, C O; Parmer, D E; Saint-Amand, R A; Harbin, C B; Roulston, J C; Ellis, R A; Buchanan, J R; Leonard, R B

    1999-01-01

    In today's health care marketplace, quality has become an expectation. Stakeholders are demanding quality clinical outcomes, and accrediting bodies are requiring clinical performance data. The Roosevelt Institute's quest was to define and quantify quality outcomes, develop an organizational culture of performance improvement, and ensure customer satisfaction. Several of the organization's leaders volunteered to work as a team to develop a specific performance improvement approach tailored to the organization. To date, over 200 employees have received an orientation to the model and its philosophy and nine problem action and process improvement teams have been formed.

  5. Development of turbine cycle performance analyzer using intelligent data mining

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Gyun Young

    2004-02-15

    In recent year, the performance enhancement of turbine cycle in nuclear power plants is being highlighted because of worldwide deregulation environment. Especially the first target of operating plants became the reduction of operating cost to compete other power plants. It is known that overhaul interval is closely related to operating cost Author identified that the rapid and reliable performance tests, analysis, and diagnosis play an important role in the control of overhaul interval through field investigation. First the technical road map was proposed to clearly set up the objectives. The controversial issues were summarized into data gathering, analysis tool, and diagnosis method. Author proposed the integrated solution on the basis of intelligent data mining techniques. For the reliable data gathering, the state analyzer composed of statistical regression, wavelet analysis, and neural network was developed. The role of the state analyzer is to estimate unmeasured data and to increase the reliability of the collected data. For the advanced performance analysis, performance analysis toolbox was developed. The purpose of this tool makes analysis process easier and more accurate by providing three novel heat balance diagrams. This tool includes the state analyzer and turbine cycle simulation code. In diagnosis module, the probabilistic technique based on Bayesian network model and the deterministic technique based on algebraical model are provided together. It compromises the uncertainty in diagnosis process and the pin-point capability. All the modules were validated by simulated data as well as actual test data, and some modules are used as industrial applications. We have a lot of thing to be improved in turbine cycle in order to increase plant availability. This study was accomplished to remind the concern about the importance of turbine cycle and to propose the solutions on the basis of academic as well as industrial needs.

  6. Development of turbine cycle performance analyzer using intelligent data mining

    International Nuclear Information System (INIS)

    Heo, Gyun Young

    2004-02-01

    In recent year, the performance enhancement of turbine cycle in nuclear power plants is being highlighted because of worldwide deregulation environment. Especially the first target of operating plants became the reduction of operating cost to compete other power plants. It is known that overhaul interval is closely related to operating cost Author identified that the rapid and reliable performance tests, analysis, and diagnosis play an important role in the control of overhaul interval through field investigation. First the technical road map was proposed to clearly set up the objectives. The controversial issues were summarized into data gathering, analysis tool, and diagnosis method. Author proposed the integrated solution on the basis of intelligent data mining techniques. For the reliable data gathering, the state analyzer composed of statistical regression, wavelet analysis, and neural network was developed. The role of the state analyzer is to estimate unmeasured data and to increase the reliability of the collected data. For the advanced performance analysis, performance analysis toolbox was developed. The purpose of this tool makes analysis process easier and more accurate by providing three novel heat balance diagrams. This tool includes the state analyzer and turbine cycle simulation code. In diagnosis module, the probabilistic technique based on Bayesian network model and the deterministic technique based on algebraical model are provided together. It compromises the uncertainty in diagnosis process and the pin-point capability. All the modules were validated by simulated data as well as actual test data, and some modules are used as industrial applications. We have a lot of thing to be improved in turbine cycle in order to increase plant availability. This study was accomplished to remind the concern about the importance of turbine cycle and to propose the solutions on the basis of academic as well as industrial needs

  7. Performance improvement - business excellence processes

    Energy Technology Data Exchange (ETDEWEB)

    Doucett, J. [NB Nuclear Power, Point Lepreau, New Brunswick (Canada)

    2010-07-01

    This presentation discusses Performance Improvement which is defined as 'the process of identifying and analyzing important organizational and individual performance gaps, planning for future performance improvement, designing and developing cost-effective and ethically justifiable intervention to close performance gaps, implementing the interventions and evaluating the financial and non-financial results', i.e. making things better. Specifically, it discusses the refurbishment outage at the Point Lepreau Power Plant that began at the end of March 2008. The business risks identified in 2008 were leadership, demographics and management system.

  8. Performance improvement - business excellence processes

    International Nuclear Information System (INIS)

    Doucett, J.

    2010-01-01

    This presentation discusses Performance Improvement which is defined as 'the process of identifying and analyzing important organizational and individual performance gaps, planning for future performance improvement, designing and developing cost-effective and ethically justifiable intervention to close performance gaps, implementing the interventions and evaluating the financial and non-financial results', i.e. making things better. Specifically, it discusses the refurbishment outage at the Point Lepreau Power Plant that began at the end of March 2008. The business risks identified in 2008 were leadership, demographics and management system.

  9. Exergy Analysis of a Subcritical Refrigeration Cycle with an Improved Impulse Turbo Expander

    Directory of Open Access Journals (Sweden)

    Zhenying Zhang

    2014-08-01

    Full Text Available The impulse turbo expander (ITE is employed to replace the throttling valve in the vapor compression refrigeration cycle to improve the system performance. An improved ITE and the corresponding cycle are presented. In the new cycle, the ITE not only acts as an expansion device with work extraction, but also serves as an economizer with vapor injection. An increase of 20% in the isentropic efficiency can be attained for the improved ITE compared with the conventional ITE owing to the reduction of the friction losses of the rotor. The performance of the novel cycle is investigated based on energy and exergy analysis. A correlation of the optimum intermediate pressure in terms of ITE efficiency is developed. The improved ITE cycle increases the exergy efficiency by 1.4%–6.1% over the conventional ITE cycle, 4.6%–8.3% over the economizer cycle and 7.2%–21.6% over the base cycle. Furthermore, the improved ITE cycle is also preferred due to its lower exergy loss.

  10. MONITORING SWIMMING SPRINT PERFORMANCE DURING A TRAINING CYCLE

    Directory of Open Access Journals (Sweden)

    Daniel A. Marinho

    2009-12-01

    Full Text Available The preparation for a major competition is an important concern of coaches and athletes. Therefore, the aim of this study was to evaluate the evolution in sprint performance during a training macro cycle in age-group swimmers of both genders. The sample comprised twenty four age-group swimmers (12.0 ± 0.72 years old, 41.43 ± 6.88 kg, 1.51 ± 0.09 m. The evaluations occurred during nine weeks of swimming training in the first macro cycle. During this period the subjects performed 54 training units (6 units per week. In all weeks, the performance in two trials of a 25 m front crawl all out test, with 15 min of rest, was recorded. Only the bestperformance was used to assess the effects of training. Comparisons between the first week and the following weeks were conducted using pair-sample t-test. The significance level was set at 5%. The sprint performance did not change during the first 6 weeks of preparation. In the last three weeks the performance in the 25 m front crawl test was improved when compared with the first week, although the major changes occurred at the last week of preparation.It seems that in age-group swimmers seven weeks of specific swimming training enables improving swimmer’s sprint performance, although some differences exists between male and female swimmers. Thesedata could be used by coaches to program the training season and the evolution of the load components.

  11. Improved Low Temperature Performance of Supercapacitors

    Science.gov (United States)

    Brandon, Erik J.; West, William C.; Smart, Marshall C.; Gnanaraj, Joe

    2013-01-01

    Low temperature double-layer capacitor operation enabled by: - Base acetonitrile / TEATFB salt formulation - Addition of low melting point formates, esters and cyclic ethers center dot Key electrolyte design factors: - Volume of co-solvent - Concentration of salt center dot Capacity increased through higher capacity electrodes: - Zeolite templated carbons - Asymmetric cell designs center dot Continuing efforts - Improve asymmetric cell performance at low temperature - Cycle life testing Motivation center dot Benchmark performance of commercial cells center dot Approaches for designing low temperature systems - Symmetric cells (activated carbon electrodes) - Symmetric cells (zeolite templated carbon electrodes) - Asymmetric cells (lithium titanate/activated carbon electrodes) center dot Experimental results center dot Summary

  12. Performance analysis of a potassium-steam two stage vapour cycle

    International Nuclear Information System (INIS)

    Mitachi, Kohshi; Saito, Takeshi

    1983-01-01

    It is an important subject to raise the thermal efficiency in thermal power plants. In present thermal power plants which use steam cycle, the plant thermal efficiency has already reached 41 to 42 %, steam temperature being 839 K, and steam pressure being 24.2 MPa. That is, the thermal efficiency in a steam cycle is facing a limit. In this study, analysis was made on the performance of metal vapour/steam two-stage Rankine cycle obtained by combining a metal vapour cycle with a present steam cycle. Three different combinations using high temperature potassium regenerative cycle and low temperature steam regenerative cycle, potassium regenerative cycle and steam reheat and regenerative cycle, and potassium bleed cycle and steam reheat and regenerative cycle were systematically analyzed for the overall thermal efficiency, the output ratio and the flow rate ratio, when the inlet temperature of a potassium turbine, the temperature of a potassium condenser, and others were varied. Though the overall thermal efficiency was improved by lowering the condensing temperature of potassium vapour, it is limited by the construction because the specific volume of potassium in low pressure section increases greatly. In the combinatipn of potassium vapour regenerative cycle with steam regenerative cycle, the overall thermal efficiency can be 58.5 %, and also 60.2 % if steam reheat and regenerative cycle is employed. If a cycle to heat steam with the bled vapor out of a potassium vapour cycle is adopted, the overall thermal efficiency of 63.3 % is expected. (Wakatsuki, Y.)

  13. Performance research on modified KCS (Kalina cycle system) 11 without throttle valve

    International Nuclear Information System (INIS)

    He, Jiacheng; Liu, Chao; Xu, Xiaoxiao; Li, Yourong; Wu, Shuangying; Xu, Jinliang

    2014-01-01

    Two modified systems based on a KCS (Kalina cycle system) 11 with a two-phase expander to substitute a throttle valve are proposed. The two-phase expander is located between the regenerator and the absorber in the B-modified cycle and between the separator and the regenerator in the C-modified cycle. A thermodynamic performance analysis of both the original KCS 11 and the modified systems is carried out. The optimization of two key parameters (the concentration of working fluid and the temperature of cooling water) is also conducted. It is shown that the two modified cycles have different performance under the investigated conditions. Results also indicate that the C-modified cycle can obtain better thermodynamic effect than the B-modified cycle. The temperature of cooling water plays an important role in improving the system performance. When the cooling water temperature drops from 303 K to 278 K, the C-modified cycle thermal efficiency can be improved by 27%. - Highlights: • Throttling valve is replaced by a two-phase expander to recover the expansion work. • Thermodynamic performance of two modified cycle systems is very different. • The maximum increase of work output by C-modified cycle compared with KCS (Kalina cycle system) 11 is 9.4%. • The ranges of ammonia content of B-modified cycle are rather larger

  14. Windows with improved energy performances

    DEFF Research Database (Denmark)

    Laustsen, Jacob Birck; Svendsen, Svend

    2003-01-01

    Heat loss through windows represents a considerable part of the total heat loss from houses. However, apart from providing daylight access and view, windows offer a unique potential for solar gain to be exploited during the heating season. Until now valuation of the energy performance of windows...... has primary focused on the heat loss coefficient, U-value. However, as the U-value, especially for the glazing part, has improved considerably during the last years, the total solar energy transmittance, g-value, has become equally important to the total energy performance of windows. Improved energy...... resulted in a window with a positive net energy gain (in short the Net Gain Window), which means that it contributes to the space heating of the building. All improvements are based on existing technology and manufacturing methods. The results from this work show that the energy performances of windows can...

  15. Maintenance of hyperglycaemia does not improve performance in a ...

    African Journals Online (AJOL)

    a glucose clamp, improves 100 km cycling time-trial (TT) performance. Design. .... each TT, subjects were permitted to ingest water ad libitum. statistical .... The effects of normal and glucose syrup work diets on the ... Fructose and glucose ...

  16. Performance investigation of an advanced multi-effect adsorption desalination (MEAD) cycle

    KAUST Repository

    Thu, Kyaw; Kim, Young Deuk; Shahzad, Muhammad Wakil; Saththasivam, Jayaprakash; Ng, Kim Choon

    2015-01-01

    This article presents the development of an advanced adsorption desalination system with quantum performance improvement. The proposed multi-effect adsorption desalination (MEAD) cycle utilizes a single heat source i.e., low-temperature hot water

  17. Process Cycle Efficiency Improvement Through Lean: A Case Study

    Directory of Open Access Journals (Sweden)

    P.V. Mohanram

    2011-06-01

    Full Text Available Lean manufacturing is an applied methodology of scientific, objective techniques that cause work tasks in a process to be performed with a minimum of non-value adding activities resulting in greatly reduced wait time, queue time, move time, administrative time, and other delays. This work addresses the implementation of lean principles in a construction equipment company. The prime objective is to evolve and test several strategies to eliminate waste on the shop floor. This paper describes an application of value stream mapping (VSM. Consequently, the present and future states of value stream maps are constructed to improve the production process by identifying waste and its sources. A noticeable reduction in cycle time and increase in cycle efficiency is confirmed. The production flow was optimized thus minimizing several non-value added activities/times such as bottlenecking time, waiting time, material handling time, etc. This case study can be useful in developing a more generic approach to design lean environment.

  18. Web-based turbine cycle performance analysis for nuclear power plants

    International Nuclear Information System (INIS)

    Heo, Gyun Young; Lee, Sung Jin; Chang, Soon Heung; Choi, Seong Soo

    2000-01-01

    As an approach to improve the economical efficiency of operating nuclear power plants, a thermal performance analysis tool for steam turbine cycle has been developed. For the validation and the prediction of the signals used in thermal performance analysis, a few statistical signal processing techniques are integrated. The developed tool provides predicted performance calculation capability that is steady-state wet steam turbine cycle simulation, and measurement performance calculation capability which determines component- and cycle-level performance indexes. Web-based interface with all performance analysis is implemented, so even remote users can achieve performance analysis. Comparing to ASME PTC6 (Performance Test Code 6), the focusing point of the developed tool is historical performance analysis rather than single accurate performance test. The proposed signal processing techniques are validated using actual plant signals, and turbine cycle models are tested by benchmarking with a commercial thermal analysis tool

  19. Techniques for Improving Spelling Performance.

    Science.gov (United States)

    Saylor, Paul

    Improving spelling performance of college students is a question of insuring that the correct information is in long-term memory and readily retrievable. Any system of spelling instruction should recognize the capacity limits of the sensory register and short-term memory; provide for identification of and concentration on the distinctive features…

  20. Programs to improve plant performance

    International Nuclear Information System (INIS)

    Felmus, N.L.

    1987-01-01

    Looking toward the 1990's, we see a period in which our industry will face the challenge of improving the performance of the nuclear plants which are built and operating. The skills and technology are at hand to make good plant performance a reality and we believe the time has come to use them to achieve that end. As reserve margins decline, utilities and their regulators will increasingly seek to tap the unexploited capacity tied up in plants operating below their optimum availability. This paper describes a number of the programs, plant improvements and operations improvements which can yield a significant increase in nuclear plant availability and capacity factor now and into the 1990's. (author)

  1. Quality improvement cycles that reduced waiting times at Tshwane ...

    African Journals Online (AJOL)

    improvement. QI in medical practices is a method for continuously finding better ways to provide better care and service.11 The QI cycle is a recognised tool for analysing and improving the efficiency and quality of healthcare services.12 QI is a team effort, requiring knowledge, skills, experience and perspective of each team ...

  2. Cycling on a Bike Desk Positively Influences Cognitive Performance.

    Directory of Open Access Journals (Sweden)

    Tine Torbeyns

    Full Text Available Cycling desks as a means to reduce sedentary time in the office has gained interest as excessive sitting has been associated with several health risks. However, the question rises if people will still be as efficient in performing their desk-based office work when combining this with stationary cycling. Therefore, the effect of cycling at 30% Wmax on typing, cognitive performance and brain activity was investigated.After two familiarisation sessions, 23 participants performed a test battery [typing test, Rey auditory verbal learning test (RAVLT, Stroop test and Rosvold continuous performance test (RCPT] with electroencephalography recording while cycling and sitting on a conventional chair.Typing performance, performance on the RAVLT and accuracy on the Stroop test and the RCPT did not differ between conditions. Reaction times on the Stroop test and the RCPT were shorter while cycling relative to sitting (p < 0.05. N200, P300, N450 and conflict SP latency and amplitude on the Stroop test and N200 and P300 on the RCPT did not differ between conditions.This study showed that typing performance and short-term memory are not deteriorated when people cycle at 30% Wmax. Furthermore, cycling had a positive effect on response speed across tasks requiring variable amounts of attention and inhibition.

  3. The impact of component performance on the overall cycle performance of small-scale low temperature organic Rankine cycles

    Science.gov (United States)

    White, M.; Sayma, A. I.

    2015-08-01

    Low temperature organic Rankine cycles offer a promising technology for the generation of power from low temperature heat sources. Small-scale systems (∼10kW) are of significant interest, however there is a current lack of commercially viable expanders. For a potential expander to be economically viable for small-scale applications it is reasonable to assume that the same expander must have the ability to be implemented within a number of different ORC applications. It is therefore important to design and optimise the cycle considering the component performance, most notably the expander, both at different thermodynamic conditions, and using alternative organic fluids. This paper demonstrates a novel modelling methodology that combines a previously generated turbine performance map with cycle analysis to establish at what heat source conditions optimal system performance can be achieved using an existing turbine design. The results obtained show that the same turbine can be effectively utilised within a number of different ORC applications by changing the working fluid. By selecting suitable working fluids, this turbine can be used to convert pressurised hot water at temperatures between 360K and 400K, and mass flow rates between 0.45kg/s and 2.7kg/s, into useful power with outputs between 1.5kW and 27kW. This is a significant result since it allows the same turbine to be implemented into a variety of applications, improving the economy of scale. This work has also confirmed the suitability of the candidate turbine for a range of low temperature ORC applications.

  4. Designer and constructor practices to ensure life cycle performance.

    OpenAIRE

    Shelton, Joelle L.

    1998-01-01

    CIVINS (Civilian Institutions) Thesis document Technology advances of the last few decades, in such areas as computing and construction materials, have inspired many attempts to improve the construction process. Many of these attempts focus on reducing costs and improving functionality, such as life cycle cost analysis and value engineering, while others, such as design-build, focus on specific phases of the life cycle. Other factors such as declining productivity, the quantity of construc...

  5. The study of the energetic performance in test cycles

    Science.gov (United States)

    Rentea, Cristian; Tuca, Alexandra; Oprean, Mircea; Marius, Bataus

    2017-10-01

    One of the most important subsystems of modern passenger cars is the transmission. This paper aims to investigate the global performances of a modern transmission in different test cycles including the newly introduced WLTC (Worldwide Harmonized Light Vehicles Test Cycle). The study is done using a complex model developed in a performant simulation environment. Transmission efficiency calculation is emphasized, the efficiency being considered variable depending on engine torque, engine speed and gear ratio. The main important parameters (vehicle speed fluctuation, overall transmission efficiency, fuel consumption ratio) needed to compare test cycles and the transmissions performance are determined.

  6. Sodium bicarbonate improves swimming performance.

    Science.gov (United States)

    Lindh, A M; Peyrebrune, M C; Ingham, S A; Bailey, D M; Folland, J P

    2008-06-01

    Sodium bicarbonate ingestion has been shown to improve performance in single-bout, high intensity events, probably due to an increase in buffering capacity, but its influence on single-bout swimming performance has not been investigated. The effects of sodium bicarbonate supplementation on 200 m freestyle swimming performance were investigated in elite male competitors. Following a randomised, double blind counterbalanced design, 9 swimmers completed maximal effort swims on 3 separate occasions: a control trial (C); after ingestion of sodium bicarbonate (SB: NaHCO3 300 mg . kg (-1) body mass); and after ingestion of a placebo (P: CaCO3 200 mg . kg (-1) body mass). The SB and P agents were packed in gelatine capsules and ingested 90 - 60 min prior to each 200 m swim. Mean 200 m performance times were significantly faster for SB than C or P (1 : 52.2 +/- 4.7; 1 : 53.7 +/- 3.8; 1 : 54.0 +/- 3.6 min : ss; p bicarbonate were all elevated pre-exercise in the SB compared to C and P trials (p < 0.05). Post-200 m blood lactate concentrations were significantly higher following the SB trial compared with P and C (p < 0.05). It was concluded that SB supplementation can improve 200 m freestyle performance time in elite male competitors, most likely by increasing buffering capacity.

  7. Bitumen nanocomposites with improved performance

    KAUST Repository

    Kosma, Vasiliki

    2017-11-29

    Bitumen-clay nanocomposite binders with styrene-butadienestyrene triblock copolymer, SBS, and combinations of SBS and crumb rubber (CR) with different CR/SBS ratios have been synthesized and characterized. In addition to the binder, samples containing the binder and concrete sand (with a weight ratio 1:9) were prepared. The modified binders were studied in terms of filler dispersion, storage stability, mechanical performance and water susceptibility. We demonstrate that the samples containing nanoclays consistently outperform those based only on the polymer additives. We also find that nanocomposite samples based on a combination of SBS and CR are best, since in addition to other improvements they show excellent storage stability. Our work shows that substituting CR with SBS as a bitumen additive and combining it with inexpensive nanoclays leads to new materials with enhanced performance and improved stability for practical asphalt applications.

  8. Improving engineers' performance with computers

    International Nuclear Information System (INIS)

    Purvis, E.E. III

    1984-01-01

    The problem addressed is how to improve the performance of engineers in the design, operation, and maintenance of nuclear power plants. The application of computer science to this problem offers a challenge in maximizing the use of developments outside the nuclear industry and setting priorities to address the most fruitful areas first. Areas of potential benefits include data base management through design, analysis, procurement, construction, operation maintenance, cost, schedule and interface control and planning, and quality engineering on specifications, inspection, and training

  9. Nuclear power performance and safety. V.5. Nuclear fuel cycle

    International Nuclear Information System (INIS)

    1988-01-01

    The International Conference on Nuclear Power Performance and Safety, organized by the International Atomic Energy Agency, was held at the Austria Centre Vienna (ACV) in Vienna, Austria, from 28 September to 2 October 1987. The objective of the Conference was to promote an exchange of worldwide information on the current trends in the performance and safety of nuclear power and its fuel cycle, and to take a forward look at the expectations and objectives for the 1990s. Policy decisions for waste management have already been taken in many countries and the 1990s should be a period of demonstration and implementation of these policies. As ilustrated by data presented from a number of countries, many years of experience in radioactive waste management have been achieved and the technology exists to implement the national plans and policies that have been developed. The establishment of criteria, the development of safety performance methodology and site investigation work are key activities essential to the successful selection, characterization and construction of geological repositories for the final disposal of radioactive waste. Considerable work has been done in these areas over the last ten years and will continue into the 1990s. However, countries that are considering geological disposal for high level waste now recognize the need for relating the technical aspects to public understanding and acceptance of the concept and decision making activities. The real challenge for the 1990s in waste disposal will be successfully to integrate technological activities within a process which responds to institutional and public concern. Volume 5 of the Proceedings comprehends the contributions on waste management in the 1990s. Decontamination and decommissioning, waste management, treatment and disposal, nuclear fuel cycle - present and future. Enrichment services and advanced reactor fuels, improvements in reactor fuel utilization and performance, spent fuel management

  10. Part-load performance of a high temperature Kalina cycle

    International Nuclear Information System (INIS)

    Modi, Anish; Andreasen, Jesper Graa; Kærn, Martin Ryhl; Haglind, Fredrik

    2015-01-01

    Highlights: • Detailed algorithm to solve high temperature Kalina cycle in part load. • A central receiver concentrating solar power plant with direct vapour generation considered as case study. • Part-load performance curves and fitted equations presented. - Abstract: The Kalina cycle has recently seen increased interest as an alternative to the conventional steam Rankine cycle. The cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine bottoming cycle, and solar power plants. The high temperature cycle layouts are inherently more complex than the low temperature layouts due to the presence of a distillation-condensation subsystem, three pressure levels, and several heat exchangers. This paper presents a detailed approach to solve the Kalina cycle in part-load operating conditions for high temperature (a turbine inlet temperature of 500 °C) and high pressure (100 bar) applications. A central receiver concentrating solar power plant with direct vapour generation is considered as a case study where the part-load conditions are simulated by changing the solar heat input to the receiver. Compared with the steam Rankine cycle, the Kalina cycle has an additional degree of freedom in terms of the ammonia mass fraction which can be varied in order to maximize the part-load efficiency of the cycle. The results include the part-load curves for various turbine inlet ammonia mass fractions and the fitted equations for these curves.

  11. Windows with improved energy performance

    DEFF Research Database (Denmark)

    Noyé, Peter Anders; Laustsen, Jacob Birck; Svendsen, Svend

    2002-01-01

    According to the Danish energy protocol, Energy 21, one of the goals with highest priority is to reduce the CO2-emission. Energy consumption for domestic heating is a major contributor to the CO2-emission; hence one of the primary efforts to reach the goal is by saving energy in the households...... performances. During the last 20 years the U-value of the glazing part of windows has been improved considerably, but the frame part has not followed the same development with respect to energy performance. Therefore an increasingly large part of the total heat loss through windows is relating to the frame...... part, for which reason, as far as energy efficiency and total economy are concerned, it has become more interesting to further develop frame structures. Traditionally, the energy performance of windows has primarily been characterised by the heat loss coefficient, U-value. However as the heat loss has...

  12. Model training across multiple breeding cycles significantly improves genomic prediction accuracy in rye (Secale cereale L.).

    Science.gov (United States)

    Auinger, Hans-Jürgen; Schönleben, Manfred; Lehermeier, Christina; Schmidt, Malthe; Korzun, Viktor; Geiger, Hartwig H; Piepho, Hans-Peter; Gordillo, Andres; Wilde, Peer; Bauer, Eva; Schön, Chris-Carolin

    2016-11-01

    Genomic prediction accuracy can be significantly increased by model calibration across multiple breeding cycles as long as selection cycles are connected by common ancestors. In hybrid rye breeding, application of genome-based prediction is expected to increase selection gain because of long selection cycles in population improvement and development of hybrid components. Essentially two prediction scenarios arise: (1) prediction of the genetic value of lines from the same breeding cycle in which model training is performed and (2) prediction of lines from subsequent cycles. It is the latter from which a reduction in cycle length and consequently the strongest impact on selection gain is expected. We empirically investigated genome-based prediction of grain yield, plant height and thousand kernel weight within and across four selection cycles of a hybrid rye breeding program. Prediction performance was assessed using genomic and pedigree-based best linear unbiased prediction (GBLUP and PBLUP). A total of 1040 S 2 lines were genotyped with 16 k SNPs and each year testcrosses of 260 S 2 lines were phenotyped in seven or eight locations. The performance gap between GBLUP and PBLUP increased significantly for all traits when model calibration was performed on aggregated data from several cycles. Prediction accuracies obtained from cross-validation were in the order of 0.70 for all traits when data from all cycles (N CS  = 832) were used for model training and exceeded within-cycle accuracies in all cases. As long as selection cycles are connected by a sufficient number of common ancestors and prediction accuracy has not reached a plateau when increasing sample size, aggregating data from several preceding cycles is recommended for predicting genetic values in subsequent cycles despite decreasing relatedness over time.

  13. Cognitive Performance in College Women Throughout the Menstrual Cycle

    Directory of Open Access Journals (Sweden)

    Fred Gustavo Manrique-Abril

    2008-05-01

    Full Text Available To determine whether fluctuations of estrogen levels across the menstrual cycle influence cognitive performance, 13 university women between 20 and 23 years old were tested in four cognitive tasks; verbal memory, visuospatial ability, short term memory and visuo-motor coordination, three times across a menstrual cycle. Radioimmunoassay tests were performed in order to determine the hormonal state. Significant differences were not found in visuo-spatial ability and visuo-motor coordination performance, but results suggest a better verbal memory performance associated with high estrogen levels; short term memory performance didn’t show to be sensitive to fluctuations in estrogen levels.

  14. The Performance of CSAM SAM when Cycle Length is extended

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Kyung-ho; Moon, Sang-rae [KHNP, Daejeon (Korea, Republic of)

    2016-10-15

    In order to verify validation of that, CPC Axial Power Distribution is compared with Axial Power Distribution based on ICI every week. The difference between CPC Axial Power Distribution and Axial Power Distribution based on ICI increases according as fuels are burned. It is called CPC Axial Power Distribution Root Mean Square Error (CPC RMS Error). SAM and calibration of ex-core detector are important factors influencing the magnitude of the difference. According to vendor, the difference is limited by 8%. Otherwise, CPC penalty increases as many as difference increase. Therefore, KHNP developed Constrained Simulated Annealing Method (CSAM), which has better performance than that of Least Square Method (LSM), to calculate SAM constant. The CSA SAM contributed largely to maintain CPC operating margin. Somewhat, KHNP is developing the technology to be able to operate nuclear power plants for 24 month to optimize their efficiency. This paper shows trends of CPC RMS Error in a case of 24 months operation. Trends are based on data of a few OPR1000s under operation. It is data of OPR1000s that CSA SAM is applied. KHNP is developing the technology to extend operation cycle length in order to optimize the operation efficiency of OPR1000. To verify effect of extended operation cycle length on CPC, CPC Axial Power Distribution RMS Error in a case of 24 months operation was expected using operation data of six cycles in OPR1000. In cases that CPC Axial Power Distribution RMS Error exceeds threshold, operation margin is decreased due to CPC penalty. To prevent CPC operation margin from being decreased, improved method to calculate SAM or to calibrate ex-core detector is required. KHNP will consider the way to maintain CPC operation margin along with 24 month operation technology development, hereafter.

  15. Improved power performance assessment methods

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S; Antoniou, I; Dahlberg, J A [and others

    1999-03-01

    The uncertainty of presently-used methods for retrospective assessment of the productive capacity of wind farms is unacceptably large. The possibilities of improving the accuracy have been investigated and are reported. A method is presented that includes an extended power curve and site calibration. In addition, blockage effects with respect to reference wind speed measurements are analysed. It is found that significant accuracy improvements are possible by the introduction of more input variables such as turbulence and wind shear, in addition to mean wind speed and air density. Also, the testing of several or all machines in the wind farm - instead of only one or two - may provide a better estimate of the average performance. (au)

  16. Investigators share improved understanding of the North American carbon cycle

    Science.gov (United States)

    Richard A. Birdsey; Robert Cook; Scott Denning; Peter Griffith; Beverly Law; Jeffrey Masek; Anna Michalak; Stephen Ogle; Dennis Ojima; Yude Pan; Christopher Sabine; Edwin Sheffner; Eric Sundquist

    2007-01-01

    The U.S. North American Carbon Program (NACP) sponsored an "all-scientist" meeting to review progress in understanding the dynamics of the carbon cycle of North American and adjacent oceans, and to chart a course for improved integration across scientifi c disciplines, scales, and Earth system boundaries. The meeting participants also addressed the need for...

  17. Innovative predictive maintenance concepts to improve life cycle management

    NARCIS (Netherlands)

    Tinga, Tiedo

    2014-01-01

    For naval systems with typically long service lives, high sustainment costs and strict availability requirements, an effective and efficient life cycle management process is very important. In this paper four approaches are discussed to improve that process: physics of failure based predictive

  18. Performance improvement through management audits

    International Nuclear Information System (INIS)

    Arter, D.R.

    1986-01-01

    We should go back to the basics of what a quality assurance program is designed to accomplish and then use that program to provide confidence to the public that actions are correct. The quality assurance management audit, if done responsible with trained people, is the best tool we have to monitor the goal of conducting business safely and correctly. Audit report should be used to project future performance and should not be used as a forum for recommendations. They should be presented in such a manner as to allow the managers involved to continually improve the work activity

  19. Fuel cycle related parametric study considering long lived actinide production, decay heat and fuel cycle performances

    International Nuclear Information System (INIS)

    Raepsaet, X.; Damian, F.; Lenain, R.; Lecomte, M.

    2001-01-01

    One of the very attractive HTGR reactor characteristics is its highly versatile and flexible core that can fulfil a wide range of diverse fuel cycles. Based on a GTMHR-600 MWth reactor, analyses of several fuel cycles were carried out without taking into account common fuel particle performance limits (burnup, fast fluence, temperature). These values are, however, indicated in each case. Fuel derived from uranium, thorium and a wide variety of plutonium grades has been considered. Long-lived actinide production and total residual decay heat were evaluated for the various types of fuel. The results presented in this papers provide a comparison of the potential and limits of each fuel cycle and allow to define specific cycles offering lowest actinide production and residual heat associated with a long life cycle. (author)

  20. General performance characteristics of an irreversible ferromagnetic Stirling refrigeration cycle

    International Nuclear Information System (INIS)

    Lin, G.; Tegus, O.; Zhang, L.; Brueck, E.

    2004-01-01

    A new magnetic-refrigeration-cycle model using ferromagnetic materials as a cyclic working substance is set up, in which finite-rate heat transfer, heat leak and regeneration time are taken into account. On the basis of the thermodynamic properties of a ferromagnetic material, the general performance characteristics of the ferromagnetic Stirling refrigeration cycle are investigated and the effects of some key irreversibilities on the performance of the cycle are revealed. By using the optimal-control theory, the optimal relation between the coefficient of performance and the cooling rate is derived and some important performance bounds, e.g., the maximum cooling rate, the maximum coefficient of performance, are determined. Moreover, the optimal operating regions for cooling rate, coefficient of performance and the optimal operating temperatures of a cyclic working substance in the two heat-transfer processes are obtained. Furthermore, the influences of magnetization and magnetic field on the performance characteristics of the cycle are discussed. The results obtained here have general significance and can be deduced to the related ones of the Stirling refrigeration cycle using paramagnetic salt as a cyclic working substance

  1. Thermodynamic performance evaluation of transcritical carbon dioxide refrigeration cycle integrated with thermoelectric subcooler and expander

    International Nuclear Information System (INIS)

    Dai, Baomin; Liu, Shengchun; Zhu, Kai; Sun, Zhili; Ma, Yitai

    2017-01-01

    New configurations of transcritical CO_2 refrigeration cycle combined with a thermoelectric (TE) subcooler and an expander (TES+EXP_H_M and TES+EXP_M_L) are proposed. The expander can operate between the high-pressure to the vessel pressure, or from vessel pressure to evaporation pressure. A power system is utilized to balance and supply power to thermoelectric subcooler and compressor. Thermodynamic performance optimizations and analyses are presented. Comparisons are carried out with the BASE, EXP_H_M, EXP_M_L, and TES cycles. The results show that the coefficient of performance (COP) improvement is more notable when the expander is installed between the liquid receiver and the evaporator. Maximum COP is obtained for the new cycles with a simultaneous optimization of discharge pressure and subcooling temperature. The new proposed TES+EXP_M_L cycle shows an excellent and steady performance than other cycles. It operates not only with the highest COP, but also the lowest discharge pressure. Under the working conditions of high gas cooler outlet temperature or low evaporation temperature, the merits of COP improvement and discharge pressure reduction are more prominent. The new cycle is more suitable for the hot regions where the CO_2 can not be sufficiently subcooled or the refrigerated space operates at low evaporation temperature. - Highlights: • New configurations of transcritical CO_2 refrigeration cycle are proposed. • New cycles are optimized and compared with other cycles. • The position of expander has an evident influence on the performance of CO_2 cycle. • TES+EXP_M_L cycle shows the highest COP and lowest discharge pressure. • The range of application for the TES+EXP_M_L cycle is recommended.

  2. Thermo-economic performance of HTGR Brayton power cycles

    International Nuclear Information System (INIS)

    Linares, J. L.; Herranz, L. E.; Moratilla, B. Y.; Fernandez-Perez, A.

    2008-01-01

    High temperature reached in High and Very High Temperature Reactors (VHTRs) results in thermal efficiencies substantially higher than those of actual nuclear power plants. A number of studies mainly driven by achieving optimum thermal performance have explored several layout. However, economic assessments of cycle power configurations for innovative systems, although necessarily uncertain at this time, may bring valuable information in relative terms concerning power cycle optimization. This paper investigates the thermal and economic performance direct Brayton cycles. Based on the available parameters and settings of different designs of HTGR power plants (GTHTR-300 and PBMR) and using the first and second laws of thermodynamics, the effects of compressor inter-cooling and of the compressor-turbine arrangement (i.e., single vs. multiple axes) on thermal efficiency have been estimated. The economic analysis has been based on the El-Sayed methodology and on the indirect derivation of the reactor capital investment. The results of the study suggest that a 1-axis inter-cooled power cycle has a similar thermal performance to the 3-axes one (around 50%) and, what's more, it is substantially less taxed. A sensitivity study allowed assessing the potential impact of optimizing several variables on cycle performance. Further than that, the cycle components costs have been estimated and compared. (authors)

  3. Improving the quality of care for patients with hypertension in Moshupa District, Botswana: Quality improvement cycle

    Directory of Open Access Journals (Sweden)

    Cathy Kande

    2014-01-01

    Full Text Available Background: Although there are no prevalence studies on hypertension in Botswana, this condition is thought to be common and the quality of care to be poor.Aim: The aim of this project was to assess and improve the quality of primary care forhypertension.Setting: Moshupa clinic and catchment area, Botswana.Methods: Quality improvement cycle.Results: Two hundred participants were included in the audit. Sixty-eight per cent were women with a mean age of 55 years. In the baseline audit none of the target standards were met. During the re-audit six months later, six out of nine structural target standards, five out of 11 process target standards and one out of two outcome target standards were achieved. Statistically-significant improvement in performance (p < 0.05 was shown in 10 criteria although the target standard was not always met. In the re-audit, the target of achieving blood pressure control (< 140/90 in 70% of patients was achieved.Conclusion: The quality of care for hypertension was suboptimal in our setting. Simple interventions were designed and implemented to improve the quality of care. These interventions led to significant improvement in structural and process criteria. A corresponding significant improvement in the control of blood pressure was also seen.

  4. A treatment of thermal efficiency improvement in the Brayton cycle

    International Nuclear Information System (INIS)

    Fujii, Terushige; Akagawa, Koji; Nakanishi, Shigeyasu; Inoue, Kiyoshi; Ishigai, Seikan.

    1982-01-01

    So far, as the working fluid for power-generating plants, mainly water and air (combustion gas) have been used. In this study, in regeneration and isothermal compression processes being considered as the means for the efficiency improvement in Brayton cycle, the investigation of equivalent graphical presentation method with T-S diagrams, the introduction of the new characteristic number expressing the possibility of thermal efficiency improvement by regeneration, and the investigation of the effect of the difference of working fluid on thermal efficiency were carried out. Next, as the cycle approximately realizing isothermal compression process with condensation process, the super-critical pressure cycle with liquid phase compression was rated, and four working fluids, NH 3 , SO 2 , CO 2 and H 2 O were examined as perfect gas and real gas. The advantage of CO 2 regeneration for the thermal efficiency improvement was clarified by using the dimensionless characteristic number. The graphical presentation of effective work, the thermal efficiency improvement by regeneration, the thermal efficiency improvement by making compression process isothermal, the effect on thermal efficiency due to various factors and working fluids, the characteristic number by regeneration, and the application to real working fluids are reported. (Kako, I.)

  5. Performances of four magnetic heat-pump cycles

    International Nuclear Information System (INIS)

    Chen, F.C.; Murphy, R.W.; Mel, V.C.; Chen, G.L.

    1990-01-01

    Magnetic heat pumps have been successfully used for refrigeration applications at near absolute-zero-degree temperatures. In these applications, a temperature lift of a few degrees in a cryogenic environment is sufficient and can be easily achieved by a simple magnetic heat-pump cycle. To extend magnetic heat pumping to other temperature ranges and other types of applications in which the temperature lift is more than just a few degrees requires more involved cycle processes. This paper investigates the characteristics of a few better-known thermomagnetic heat-pump cycles (Carnot, Ericsson, Stirling, and regenerative) in extended ranges of temperature lift. The regenerative cycle is the most efficient one. For gadolinium operating between 0 and 7 T (Tesla) in a heat pump cycle with a heat-rejection temperature of 320 K, our analysis predicted a 42% loss in coefficient of performance at 260 K cooling temperature, and a 15% loss in capacity at 232 K cooling temperature for the constant-field cycle as compared with the ideal regenerative cycle. Such substantial penalties indicate that the potential irreversibilities from this one source (the additional heat transfer that would be needed for the constant-field vs. the ideal regenerative cycle) may adversely affect the viability of certain proposed MHP concepts if the relevant loss mechanisms are not adequately addressed

  6. Improvements in steam cycle electric power generating plants

    International Nuclear Information System (INIS)

    Bienvenu, Claude.

    1973-01-01

    The invention relates to a steam cycle electric energy generating plants of the type comprising a fossil or nuclear fuel boiler for generating steam and a turbo alternator group, the turbine of which is fed by the boiler steam. The improvement is characterized in that use is made of a second energy generating group in which a fluid (e.g. ammoniac) undergoes a condensation cycle the heat source of said cycle being obtained through a direct or indirect heat exchange with a portion of the boiler generated steam whereby it is possible without overloading the turbo-alternator group, to accomodate any increase of the boiler power resulting from the use of another fuel while maintaining a maximum energy output. This can be applied to electric power stations [fr

  7. Neuropsychological performance and menstrual cycle: a literature review

    OpenAIRE

    Souza,Eliana Gonçalves V.; Ramos,Melissa G.; Hara,Cláudia; Stumpf,Bárbara Perdigão; Rocha,Fábio L.

    2012-01-01

    Approximately 80% of all women of reproductive age experience psychological and physical changes associated with the premenstrual phase. Cognitive alterations are among the most common complaints. In this context, studies have assessed cognitive performance across the menstrual cycle in healthy women and also in women with premenstrual syndrome (PMS). The main objective of the present study was to review the literature on cognitive function in different phases of the menstrual cycle in women ...

  8. Caffeine withdrawal and high-intensity endurance cycling performance.

    Science.gov (United States)

    Irwin, Christopher; Desbrow, Ben; Ellis, Aleisha; O'Keeffe, Brooke; Grant, Gary; Leveritt, Michael

    2011-03-01

    In this study, we investigated the impact of a controlled 4-day caffeine withdrawal period on the effect of an acute caffeine dose on endurance exercise performance. Twelve well-trained and familiarized male cyclists, who were caffeine consumers (from coffee and a range of other sources), were recruited for the study. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials. Participants abstained from dietary caffeine sources for 4 days before the trials and ingested capsules (one in the morning and one in the afternoon) containing either placebo or caffeine (1.5 mg · kg(-1) body weight · day(-1)). On day 5, capsules containing placebo or caffeine (3 mg · kg(-1) body weight) were ingested 90 min before completing a time trial, equivalent to one hour of cycling at 75% peak sustainable power output. Hence the study was designed to incorporate placebo-placebo, placebo-caffeine, caffeine-placebo, and caffeine-caffeine conditions. Performance time was significantly improved after acute caffeine ingestion by 1:49 ± 1:41 min (3.0%, P = 0.021) following a withdrawal period (placebo-placebo vs. placebo-caffeine), and by 2:07 ± 1:28 min (3.6%, P = 0.002) following the non-withdrawal period (caffeine-placebo vs. caffeine-caffeine). No significant difference was detected between the two acute caffeine trials (placebo-caffeine vs. caffeine-caffeine). Average heart rate throughout exercise was significantly higher following acute caffeine administration compared with placebo. No differences were observed in ratings of perceived exertion between trials. A 3 mg · kg(-1) dose of caffeine significantly improves exercise performance irrespective of whether a 4-day withdrawal period is imposed on habitual caffeine users.

  9. improving performance of laying hens

    Directory of Open Access Journals (Sweden)

    A.P Sinurat

    2012-10-01

    Full Text Available A trial was conducted in order to study the effect of the supplementation of Avizyme 1500® (Danisco Animal Nutrition, Marlborough, UK on the performance of laying hens for one year. A control diet based on corn – soybean meal was formulated to meet nutrient requirement of ISA Brown laying hens. Two treatments, the control diet (C and C + 1000 g Avizyme/tonne diet were tested. Each diet was fed to 80 birds (20 replicates of 4 birds from 20 to 72 weeks of age, and performances of birds (feed intake, egg production, egg size, egg mass, feed conversion ratio, and egg quality were measured. All data were subject to analyses of variance following the t-test. Results showed that the addition of Avizyme 1500 to the feed reduced feed intake by 4% (P < 0.01, mortality by 75 % or from 15% to 3.75% (P < 0.01 and improved the feed conversion ratio by 3 % (P < 0.05. The high mortality of the control treatment (15% is explained by an E.coli infection that was observed following the post-mortem examination of dead birds. The egg production (HD and HH, egg size and egg mass however were not significantly affected by the Avizyme supplementation. Egg quality (HU, yolk colour score, yolk weight and shell thickness was not significantly affected by Avizyme supplementation. It can be concluded that the supplementation of 1000 g Avizyme /tonne of diet improved feed efficiency and this was mediated via a reduction in feed intake.

  10. Measuring collections effort improves cash performance.

    Science.gov (United States)

    Shutts, Joe

    2009-09-01

    Having a satisfied work force can lead to an improved collections effort. Hiring the right people and training them ensures employee engagement. Measuring collections effort and offering incentives is key to revenue cycle success.

  11. Improving Life-Cycle Cost Management of Spacecraft Missions

    Science.gov (United States)

    Clardy, Dennon

    2010-01-01

    This presentation will explore the results of a recent NASA Life-Cycle Cost study and how project managers can use the findings and recommendations to improve planning and coordination early in the formulation cycle and avoid common pitfalls resulting in cost overruns. The typical NASA space science mission will exceed both the initial estimated and the confirmed life-cycle costs by the end of the mission. In a fixed-budget environment, these overruns translate to delays in starting or launching future missions, or in the worst case can lead to cancelled missions. Some of these overruns are due to issues outside the control of the project; others are due to the unpredictable problems (unknown unknowns) that can affect any development project. However, a recent study of life-cycle cost growth by the Discovery and New Frontiers Program Office identified a number of areas that are within the scope of project management to address. The study also found that the majority of the underlying causes for cost overruns are embedded in the project approach during the formulation and early design phases, but the actual impacts typically are not experienced until late in the project life cycle. Thus, project management focus in key areas such as integrated schedule development, management structure and contractor communications processes, heritage and technology assumptions, and operations planning, can be used to validate initial cost assumptions and set in place management processes to avoid the common pitfalls resulting in cost overruns.

  12. Effects of music tempo upon submaximal cycling performance.

    Science.gov (United States)

    Waterhouse, J; Hudson, P; Edwards, B

    2010-08-01

    In an in vivo laboratory controlled study, 12 healthy male students cycled at self-chosen work-rates while listening to a program of six popular music tracks of different tempi. The program lasted about 25 min and was performed on three occasions--unknown to the participants, its tempo was normal, increased by 10% or decreased by 10%. Work done, distance covered and cadence were measured at the end of each track, as were heart rate and subjective measures of exertion, thermal comfort and how much the music was liked. Speeding up the music program increased distance covered/unit time, power and pedal cadence by 2.1%, 3.5% and 0.7%, respectively; slowing the program produced falls of 3.8%, 9.8% and 5.9%. Average heart rate changes were +0.1% (faster program) and -2.2% (slower program). Perceived exertion and how much the music was liked increased (faster program) by 2.4% and 1.3%, respectively, and decreased (slower program) by 3.6% and 35.4%. That is, healthy individuals performing submaximal exercise not only worked harder with faster music but also chose to do so and enjoyed the music more when it was played at a faster tempo. Implications of these findings for improving training regimens are discussed.

  13. Performance of an organic Rankine cycle with multicomponent mixtures

    International Nuclear Information System (INIS)

    Chaitanya Prasad, G.S.; Suresh Kumar, C.; Srinivasa Murthy, S.; Venkatarathnam, G.

    2015-01-01

    There is a renewed interest in ORC (organic Rankine cycle) systems for power generation using solar thermal energy. Many authors have studied the performance of ORC with different pure fluids as well as binary zeotropic mixtures in order to improve the thermal efficiency. It has not been well appreciated that zeotropic mixtures can also be used to reduce the size and cost of an ORC system. The main objective of this paper is to present mixtures that help reduce the cost while maintaining high thermal efficiency. The proposed method also allows us to design an optimum mixture for a given expander. This new approach is particularly beneficial for designing mixtures for small ORC systems operating with solar thermal energy. A number of examples are presented to demonstrate this concept. - Highlights: • The performance of an ORC operating with different zeotropic multicomponent mixtures is presented. • A thermodynamic method is proposed for the design of multicomponent mixtures for ORC power plants. • High exergy efficiency as well as high volumetric expander work can be achieved with appropriate mixtures. • The method allows design of mixtures that can be used with off-the-shelf positive displacement expanders

  14. Improving early cycle economic evaluation of diagnostic technologies.

    Science.gov (United States)

    Steuten, Lotte M G; Ramsey, Scott D

    2014-08-01

    The rapidly increasing range and expense of new diagnostics, compels consideration of a different, more proactive approach to health economic evaluation of diagnostic technologies. Early cycle economic evaluation is a decision analytic approach to evaluate technologies in development so as to increase the return on investment as well as patient and societal impact. This paper describes examples of 'early cycle economic evaluations' as applied to diagnostic technologies and highlights challenges in its real-time application. It shows that especially in the field of diagnostics, with rapid technological developments and a changing regulatory climate, early cycle economic evaluation can have a guiding role to improve the efficiency of the diagnostics innovation process. In the next five years the attention will move beyond the methodological and analytic challenges of early cycle economic evaluation towards the challenge of effectively applying it to improve diagnostic research and development and patient value. Future work in this area should therefore be 'strong on principles and soft on metrics', that is, the metrics that resonate most clearly with the various decision makers in this field.

  15. Thermodynamic performance optimization of a combined power/cooling cycle

    International Nuclear Information System (INIS)

    Pouraghaie, M.; Atashkari, K.; Besarati, S.M.; Nariman-zadeh, N.

    2010-01-01

    A combined thermal power and cooling cycle has already been proposed in which thermal energy is used to produce work and to generate a sub-ambient temperature stream that is suitable for cooling applications. The cycle uses ammonia-water mixture as working fluid and is a combination of a Rankine cycle and absorption cycle. The very high ammonia vapor concentration, exiting turbine under certain operating conditions, can provide power output as well as refrigeration. In this paper, the goal is to employ multi-objective algorithms for Pareto approach optimization of thermodynamic performance of the cycle. It has been carried out by varying the selected design variables, namely, turbine inlet pressure (P h ), superheater temperature (T superheat ) and condenser temperature (T condensor ). The important conflicting thermodynamic objective functions that have been considered in this study are turbine work (w T ), cooling capacity (q cool ) and thermal efficiency (η th ) of the cycle. It is shown that some interesting and important relationships among optimal objective functions and decision variables involved in the combined cycle can be discovered consequently. Such important relationships as useful optimal design principles would have not been obtained without the use of a multi-objective optimization approach.

  16. Round and Round We Go: An "Action" Ride on the Rehearsing and Performing Cycle

    Science.gov (United States)

    Pulman, Mark

    2012-01-01

    This article discusses the use of action research cycles on a course involving groupwork rehearsing and performance. The aim was to explore various pedagogic aspects of the activities and improve tutor practice. This account of four action research spirals, taking place over a 10-year period of rehearsing and performing, considers their management…

  17. WWER-440 fuel cycles possibilities using improved fuel assemblies design

    International Nuclear Information System (INIS)

    Mikolas, P.; Svarny, J.

    2008-01-01

    Practically five years cycle has been achieved in the last years at NPP Dukovany. There are two principal means how it could be achieved. First, it is necessary to use fuel assemblies with higher fuel enrichment and second, to use fuel loading with very low leakage. Both these conditions are fulfilled at NPP Dukovany at this time. It is known, that the fuel cycle economy can be improved by increasing the fuel residence time in the core up to six years. There are at least two ways how this goal could be achieved. The simplest way is to increase enrichment in fuel. There exists a limit, which is 5.0 w % of 235 U. Taking into account some uncertainty, the calculation maximum is 4.95 w % of 235 U. The second way is to change fuel assembly design. There are several possibilities, which seem to be suitable from the neutron - physical point of view. The first one is higher mass content of uranium in a fuel assembly. The next possibility is to enlarge pin pitch. The last possibility is to 'omit' FA shroud. This is practically unrealistic; anyway, some other structural parts must be introduced. The basic neutron physical characteristics of these cycles for up-rated power are presented showing that the possibilities of fuel assemblies with this improved design in enlargement of fuel cycles are very promising. In the end, on the basis of neutron physical characteristics and necessary economical input parameters, a preliminary evaluation of economic contribution of proposals of advanced fuel assemblies on fuel cycle economy is presented (Authors)

  18. Concept Evaluation Using the PDSA Cycle for Continuous Quality Improvement.

    Science.gov (United States)

    Laverentz, Delois Meyer; Kumm, Sharon

    As concept-based nursing education gains popularity, there is little literature on how to sustain quality after initiation of the curriculum. Critical appraisal of concepts in a university program revealed varying definitions, attributes, and exemplars resulting in student confusion. The Plan, Do, Study, Act (PDSA) cycle for continuous quality improvement was used for concept evaluation. The goals of the evaluation project were: 1) to develop common definition and attributes for concepts and 2) to develop horizontal and vertical leveling of exemplars to build on prior student learning. The continuous quality improvement process can be used to prevent "concept creep" and ensure internal consistency of concept definitions, attributes, and exemplars.

  19. Nanosatellite Architectures for Improved Study of the Hydrologic Cycle

    Science.gov (United States)

    Blackwell, W. J.; Osaretin, I.; Cahoy, K.

    2012-12-01

    The need for low-cost, mission-flexible, and rapidly deployable spaceborne sensors that meet stringent performance requirements pervades the NASA Earth Science measurement programs, including especially the recommended NRC Decadal Survey missions. To address these challenges, we present nanosatellite constellation architectures that would profoundly improve both the performance and cost/risk/schedule profiles of NASA Earth and Space Science missions by leveraging recent technology advancements. As a key enabling element, we describe a scalable and mission-flexible 6U CubeSat-based self-organizing constellation architecture (the Distributed Observatory for Monitoring of Earth, henceforth "DOME") that will achieve state-of-the-art performance (and beyond) relative to current systems with respect to spatial, spectral, and radiometric resolution. A focus of this presentation is an assessment of the viability of a cross-linked CubeSat constellation with onboard propulsion systems for high-fidelity Earth and Space Science research. Such architecture could provide game-changing advances by reducing costs by at least an order of magnitude while increasing robustness to launch and sensor failures, allowing fast-track insertion of new technologies, and improving science performance. High-resolution passive microwave atmospheric sounding is an ideal sensing modality for nanosatellite implementation due to rapidly advancing microwave and millimeterwave receiver technology. The DOME constellation would nominally comprise 6U CubeSat Microwave Atmospheric Sounder (CMAS) satellites. Each CMAS satellite would host a complete 6U CubeSat atmospheric sounder, including a radiometer payload module with passive microwave receivers operating near atmospheric absorption lines near 60 and 183.31 GHz, and a spacecraft bus with attitude determination and control, avionics, power, cross-linked communications (spacecraft-to-spacecraft and spacecraft-to-ground), and propulsion systems. A

  20. Guidelines to perform Life Cycle Analysis of Buildings

    NARCIS (Netherlands)

    Blok, R.; Gervasio, H.; Braganca, L.; Koukkari, H.; Blok, R.

    2008-01-01

    This paper gives a short introduction and attempts to give guidelines on how to perform a life Cycle Analysis (LCA) of a Building. Because a building is a complex system with many subsystems with building elements out of different materials, each fulfilling different functions the LCA of a building

  1. Age-related decrements in cycling and running performance ...

    African Journals Online (AJOL)

    South African Journal of Sports Medicine ... This study examined age-related decrements in athletic performance during running and cycling activities. ... These findings establish a trend that there is 'accelerated' aging during running which can perhaps be attributed to the increased weight-bearing stress on the muscles ...

  2. Improved cycling and high rate performance of core-shell LiFe1/3Mn1/3Co1/3PO4/carbon nanocomposites for lithium-ion batteries: Effect of the carbon source

    International Nuclear Information System (INIS)

    Li, Huanhuan; Chen, Yi; Chen, Long; Jiang, Haobin; Wang, Yaping; Wang, Hongbo; Li, Guochun; Li, Yunxing; Yuan, Yuan

    2014-01-01

    Highlights: • We report a fast microwave heating way to prepare LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /C. • The effects of different carbon sources were discussed in detail. • LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP2000 shows a discharge capacity of 160 mA h g −1 at 0.1 C. • LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP2000 elucidates excellent cyclic stability. • LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP2000 exhibits attractive rate capability. - Abstract: Core-shell type olivine solid solutions, LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /C, are synthesized via a very simple and rapid microwave heating route with different carbon sources. The obatined LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /C materials are characterized thoroughly by various analytical techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy-dispersive spectroscopy instrument. The particle sizes and distribution of the carbon layer of BP2000 carbon black coated LiFe 1/3 Mn 1/3 Co 1/3 PO 4 (LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP) are more uniform than that obtained from acetylene black (LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /AB) and Super P (LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /SP). Moreover, the LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP nanocomposite shows superior electrochemical properties such as high discharge capacity of 160 mA h g −1 at 0.1 C, excellent cyclic stability (143 mA h g −1 at 0.1 C after 30 cycles) and rate capability (76 mAh g −1 at 20 C), which are better than other two samples. Cyclic voltammetric and electrical tests disclose that the Li-ion diffusion, the reversibility of lithium extraction/insertion and electrical conductivity are significantly improved in LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP composite. Electrochemical impedance spectroscopy illustrates that LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP composite electrode possesses low contact and charge-transfer impedances, which can lead to rapid electron transport during the electrochemical lithium insertion/extraction reaction. It is believed that olivine solid

  3. Measuring and improving infrastructure performance

    National Research Council Canada - National Science Library

    Committee on Measuring and Improving Infrastructure Performance, National Research Council

    .... Developing a framework for guiding attempts at measuring the performance of infrastructure systems and grappling with the concept of defining good performance are the major themes of this book...

  4. An Improved Multi-Evaporator Adsorption Desalination Cycle for GCC Countries

    KAUST Repository

    Shahzad, Muhammad Wakil

    2017-03-29

    In Gulf Cooperation Council (GCC) countries, cogeneration based desalination processes consume almost 25% of the total annual energy and it is increasing at 2.2% annually. The high fresh water demand is attributed to high gross domestic product (GDP) growth rate, 24%, and the high water languishes, more than 10%. Over the past two decades, GCC countries have spent tens of billion dollars to expand their present and planned desalination capacities. It is foreseeable that with business-as-usual scenario, the domestic oil consumption of Saudi Arabia may exceed its production capacity by 2040. Innovative and sustainable water production solutions are needed urgently for future water supplies without environment impact. In this paper, a hybrid desalination cycle is proposed by integrating multi cascaded-evaporators (CE) with an adsorption cycle (AD). In this new innovative cycle, AD desorbed vapors are supplied to the CE to exploit the latent condensation energy within the evaporators arranged in both pressures-temperatures cascaded manner to improves the performance ratio (PR) of the cycle. Hybrid cycle shows more than 10 folds water production improvement as compared to conventional AD cycle due to synergetic effect. This concept is demonstrated in a laboratory pilot plant using a 3 cascaded evaporators pilot and simulation of 8 evaporators hybrid cycle.

  5. Performance analysis of humid air turbine cycle with solar energy for methanol decomposition

    International Nuclear Information System (INIS)

    Zhao, Hongbin; Yue, Pengxiu

    2011-01-01

    According to the physical and chemical energy cascade utilization and concept of synthesis integration of variety cycle systems, a new humid air turbine (HAT) cycle with solar energy for methanol decomposition has been proposed in this paper. The solar energy is utilized for methanol decomposing as a heat source in the HAT cycle. The low energy level of solar energy is supposed to convert the high energy level of chemical energy through methanol absorption, realizing the combination of clean energy and normal chemical fuels as compared to the normal chemical recuperative cycle. As a result, the performance of normal chemical fuel thermal cycle can be improved to some extent. Though the energy level of decomposed syngas from methanol is decreased, the cascade utilization of methanol is upgraded. The energy level and exergy losses in the system are graphically displayed with the energy utilization diagrams (EUD). The results show that the cycle's exergy efficiency is higher than that of the conventional HAT cycle by at least 5 percentage points under the same operating conditions. In addition, the cycle's thermal efficiency, exergy efficiency and solar thermal efficiency respond to an optimal methanol conversion. -- Highlights: → This paper proposed and studied the humid air turbine (HAT) cycle with methanol through decomposition with solar energy. → The cycle's exergy efficiency is higher than that of the conventional HAT cycle by at least 5 percentage points. → It is estimated that the solar heat-work conversion efficiency is about 39%, higher than usual. → There is an optimal methanol conversation for the cycle's thermal efficiency and exergy efficiency at given π and TIT. → Using EUD, the exergy loss is decreased by 8 percentage points compared with the conventional HAT cycle.

  6. Equipment improvements for performance enhancement

    International Nuclear Information System (INIS)

    Gaestel, P.; Guesnon, H.; Sauze, G.

    1994-01-01

    In order to enhance the reactor availability, several improvements on reactor equipment have been developed: design optimization for stator maintenance replacement in the main alternator; adjustment modification of stator coils in the main alternator for an easier maintenance; improvement of the fuel handling line (pole crane, transfer equipment, loading machine); development of a loose part trapping system in the steam generator secondary circuit. 1 tab

  7. Tradeoffs in fuel cycle performance for most promising options - 15346

    International Nuclear Information System (INIS)

    Taiwo, T.; Kim, T.K.; Feng, B.; Stauff, N.; Hoffman, E.; Ganda, F.; Todosow, M.; Brown, N.; Raitses, G.; Gehin, J.; Powers, J.; Youinou, G.; Hiruta, H.; Wigeland, R.

    2015-01-01

    A recent Evaluation and Screening (E/S) study of nuclear fuel cycle options was conducted by grouping all potential options into 40 Evaluation Groups (EGs) based on similarities in fundamental physics characteristics and fuel cycle performance. Through a rigorous evaluation process considering benefit and challenge metrics, 4 of these EGs were identified by the E/S study as 'most promising'. All 4 involve continuous recycle of U/Pu or U/TRU with natural uranium feed in fast critical reactors. However, these most promising EGs also include fuel cycle groups with variations on feed materials, neutron spectra, and reactor criticality. Therefore, the impacts of the addition of natural thorium fuel feed to a system that originally only used natural uranium fuel feed, using an intermediate spectrum instead of a fast spectrum, and using externally-driven systems versus critical reactors were evaluated. It was found that adding thorium to the natural uranium feed mixture leads to lower burnup, higher mass flows, and degrades fuel cycle benefit metrics (waste management, resource utilization, etc.) for fuel cycles that continuously recycle U/Pu or U/TRU. Adding thorium results in fissions of 233 U instead of just 239 Pu and in turn results in a lower average number of neutrons produced per absorption (η) for the fast reactor system. For continuous recycling systems, the lower η results in lower excess reactivity and subsequently lower achievable fuel burnup. This in turn leads to higher mass flows (fabrication, reprocessing, disposal, etc.) to produce a given amount of energy and subsequent lower metrics performance. The investigated fuel cycle options with intermediate spectrum reactors also exhibited degraded performance in the benefit metrics compared to fast spectrum reactors. Similarly, this is due to lower η values as the spectrum softens. The best externally-driven systems exhibited similar performance as fast critical reactors in terms of mass flows

  8. Improving performance with accident tolerant-fuels

    International Nuclear Information System (INIS)

    Gomes, Daniel S.; Muniz, Rafael O.R.; Giovedi, Claudia; Universidade de São Paulo

    2017-01-01

    After the Fukushima reactor accident, efforts to improve risk management in nuclear operations have included the intensification of research on accident-tolerant fuels (ATFs). In this investigation, the physical properties of recently developed ATFs were compared with those of the current standard fuel, UO 2 - Zr. The goals for innovative fuel design include a rigorous characterization of the thermal, mechanical, and chemical considerations. The intentions are to lengthen the burnup cycle, raise the power density, and improve safety. Fuels must have a high uranium density - above that supported by UO 2 - and possess a coating that exhibits better oxidation resistance than Zircaloys. ATFs such as U 3 Si 2 , UN, and UC contain a higher uranium density and thermal conductivity than UO 2 , providing significant benefits. The ideal combination of fuel and cladding must increase performance in a loss-of-coolant accident. However, U 3 Si 2 , UN, and UC have a disadvantage; their respective swelling rates are higher than that of UO 2 . These ATFs also have thermal conductivities approximately four times higher than that of UO 2 . A study was conducted investigating the hydrogen generated by the oxidation of zirconium alloys in contact with steam using cladding options such as Fe-Cr-Al and silicon carbide. It was confirmed that ferritic alloys offer a better response under severe conditions, because of their mechanical properties as creep rate. The findings of this study indicate that advanced fuels should replace UO 2 - Zr as the fuel system of choice. (author)

  9. Performance analysis of an integrated gas-, steam- and organic fluid-cycle thermal power plant

    International Nuclear Information System (INIS)

    Oko, C.O.C.; Njoku, I.H.

    2017-01-01

    This paper presents the performance analysis of an existing combined cycle power plant augmented with a waste heat fired organic Rankine cycle power plant for extra power generation. This was achieved by performing energy and exergy analysis of the integrated gas-, steam- and organic fluid-cycle thermal power plant (IPP). Heat source for the subcritical organic Rankine cycle (ORC) was the exhaust flue gases from the heat recovery steam generators of a 650 MW natural gas fired combined cycle power plant. The results showed that extra 12.4 MW of electricity was generated from the attached ORC unit using HFE7100 as working fluid. To select ORC working fluid, ten isentropic fluids were screened and HFE7100 produced the highest net power output and cycle efficiency. Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively. The rate of exergy destruction in the existing combined cycle plant was highest in the combustion chamber, 59%, whereas in the ORC, the highest rate of exergy destruction occurred in the evaporator, 62%. Simulations showed exergy efficiency of the IPP decreased with increasing ambient temperature. Exit stack flue gas temperature reduced from 126 °C in the combined cycle power plant to 100 °C in the integrated power plant. - Highlights: • Combined cycle plant retrofitted with ORC produced extra 12.4 MW electric power. • ORC is powered with low temperature flue gas from an existing combined cycle plant. • Exergy destruction rate in integrated plant(IPP) is less than in combined plant. • Exit stack temperature of the IPP has less environmental thermal pollution. • Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively.

  10. Performance review: PBMR closed cycle gas turbine power plant

    International Nuclear Information System (INIS)

    Pradeep Kumar, K.N.; Tourlidakis, A.; Pilidis, P.

    2001-01-01

    Helium is considered as one of the ideal working fluid for closed cycle using nuclear heat source due to its low neutron absorption as well as high thermodynamic properties. The commercial viability of the Helium turbo machinery depends on operational success. The past attempts failed due to poor performances manifested in the form of drop in efficiency, inability to reach maximum load, slow response to the transients etc. Radical changes in the basic design were suggested in some instances as possible solutions. A better understanding of the operational performance is necessary for the detailed design of the plant and the control systems. This paper describes the theory behind the off design and transient modelling of a closed cycle gas turbine plant. A computer simulation model has been created specifically for this cycle. The model has been tested for various turbine entry temperatures along the steady state and its replications at various locations were observed. The paper also looks at the various control methods available for a closed cycle and some of the options were simulated. (author)

  11. Improvement of Cycle Dependent Core Model for NPP Simulator

    International Nuclear Information System (INIS)

    Song, J. S.; Koo, B. S.; Kim, H. Y. and others

    2003-11-01

    The purpose of this study is to establish automatic core model generation system and to develop 4 cycle real time core analysis methodology with 5% power distribution and 500 pcm reactivity difference criteria for nuclear power plant simulator. The standardized procedure to generate database from ROCS and ANC, which are used for domestic PWR core design, was established for the cycle specific simulator core model generation. An automatic data interface system to generate core model also established. The system includes ARCADIS which edits group constant and DHCGEN which generates interface coupling coefficient correction database. The interface coupling coefficient correction method developed in this study has 4 cycle real time capability and accuracies of which the maximum differences between core design results are within 103 pcm reactivity, 1% relative power distribution and 6% control rod worth. A nuclear power plant core simulation program R-MASTER was developed using the methodology and applied by the concept of distributed client system in simulator. The performance was verified by site acceptance test in Simulator no. 2 in Kori Training Center for 30 initial condition generation and 27 steady state, transient and postulated accident situations

  12. Improvement of Cycle Dependent Core Model for NPP Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Song, J. S.; Koo, B. S.; Kim, H. Y. and others

    2003-11-15

    The purpose of this study is to establish automatic core model generation system and to develop 4 cycle real time core analysis methodology with 5% power distribution and 500 pcm reactivity difference criteria for nuclear power plant simulator. The standardized procedure to generate database from ROCS and ANC, which are used for domestic PWR core design, was established for the cycle specific simulator core model generation. An automatic data interface system to generate core model also established. The system includes ARCADIS which edits group constant and DHCGEN which generates interface coupling coefficient correction database. The interface coupling coefficient correction method developed in this study has 4 cycle real time capability and accuracies of which the maximum differences between core design results are within 103 pcm reactivity, 1% relative power distribution and 6% control rod worth. A nuclear power plant core simulation program R-MASTER was developed using the methodology and applied by the concept of distributed client system in simulator. The performance was verified by site acceptance test in Simulator no. 2 in Kori Training Center for 30 initial condition generation and 27 steady state, transient and postulated accident situations.

  13. Process improvement by cycle time reduction through Lean Methodology

    Science.gov (United States)

    Siva, R.; patan, Mahamed naveed khan; lakshmi pavan kumar, Mane; Purusothaman, M.; pitchai, S. Antony; Jegathish, Y.

    2017-05-01

    In present world, every customer needs their products to get on time with good quality. Presently every industry is striving to satisfy their customer requirements. An aviation concern trying to accomplish continuous improvement in all its projects. In this project the maintenance service for the customer is analyzed. The maintenance part service is split up into four levels. Out of it, three levels are done in service shops and the fourth level falls under customer’s privilege to change the parts in their aircraft engines at their location. An enhancement for electronics initial provisioning (eIP) is done for fourth level. Customers request service shops to get their requirements through Recommended Spare Parts List (RSPL) by eIP. To complete this RSPL for one customer, it takes 61.5 hours as a cycle time which is very high. By mapping current state VSM and takt time, future state improvement can be done in order to reduce cycle time using Lean tools such as Poke-Yoke, Jidoka, 5S, Muda etc.,

  14. Effects of caloric restriction and overnight fasting on cycling endurance performance.

    Science.gov (United States)

    Ferguson, Lisa M; Rossi, Kelly A; Ward, Emily; Jadwin, Emily; Miller, Todd A; Miller, Wayne C

    2009-03-01

    In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance. Cyclists often try to lose weight before race season to improve body composition and optimize PWR. Research has demonstrated body fat-reducing benefits of exercise after fasting overnight. We hypothesized that fasted-state exercise in calorie-restricted trained cyclists would not result in performance decrements and that their PWR would improve significantly. We also hypothesized that substrate use during fasted-state submaximal endurance cycling would shift to greater reliance on fat. Ten trained, competitive cyclists completed a protocol consisting of baseline testing, 3 weeks of caloric restriction (CR), and post-CR testing. The testing sessions measured pre- and post-CR values for resting metabolic rate (RMR), body composition, VO2, PWR and power-to-lean weight ratio (PLWR), and power output, as well as 2-hour submaximal cycling performance, rating of perceived exertion (RPE), and respiratory exchange ratio (RER). There were no significant differences between baseline and post-CR for submaximal trial RER, power output, VO2, RMR, VO2max, or workload at VO2max. However, RPE was significantly lower, and PWR was significantly higher post-CR, whereas RER did not change. The cyclists' PWR and body composition improved significantly, and their overall weight, fat weight, and body fat percentage decreased. Lean mass was maintained. The cyclists' RPE decreased significantly during 2 hours of submaximal cycling post-CR, and there was no decrement in submaximal or maximal cycling performance after 3 weeks of CR combined with overnight fasting. Caloric restriction (up to 40% for 3 weeks) and exercising after fasting overnight can improve a cyclist's PWR without compromising endurance cycling performance.

  15. Autoclave cycle optimization for high performance composite parts manufacturing

    OpenAIRE

    Nele, L.; Caggiano, A.; Teti, R.

    2016-01-01

    In aeronautical production, autoclave curing of composite parts must be performed according to a specified diagram of temperature and pressure vs time. Part-tool assembly thermal inertia and shape have a large influence on the heating and cooling rate, and therefore on the dwell time within the target temperature range. When simultaneously curing diverse composite parts, the total autoclave cycle time is driven by the part-tool assembly with the lower heating and cooling rates. With the aim t...

  16. Performance evaluation of combined ejector LiBr/H2O absorption cooling cycle

    Directory of Open Access Journals (Sweden)

    Hasan Sh. Majdi

    2016-03-01

    Full Text Available The objective of this work is to develop a computer simulation program to evaluate the performance of solar-assited combined ejector absorption (single-effect cooling system using LiBr/H2O as a working fluid and operating under steady-state conditions. The ejector possess no moving parts and is simple and reliable, which makes it attractive for combination with single-stage absorption cycle for further improvement to the system's performance. In this research, improvement to the system is achieved by utilizing the potential kinetic energy of the ejector to enhance refrigeration efficiency. The effects of the entrainment ratio of the ejector, operating temperature, on the thermal loads, and system performance have been investigated. The results showed that the evaporator and condenser loads, post-addition of the ejector, is found to be permanently higher than that in the basic cycle, which indicates a significant enhancement of the proposed cycle and the cooling capacity of the system increasing with the increase in evaporator temperature and entrainment ratio. The COP of the modified cycle is improved by up to 60 % compared with that of the basic cycle at the given condition. This process stabilizes the refrigeration system, enhanced its function, and enabled the system to work under higher condenser temperatures.

  17. Benchmark for Strategic Performance Improvement.

    Science.gov (United States)

    Gohlke, Annette

    1997-01-01

    Explains benchmarking, a total quality management tool used to measure and compare the work processes in a library with those in other libraries to increase library performance. Topics include the main groups of upper management, clients, and staff; critical success factors for each group; and benefits of benchmarking. (Author/LRW)

  18. Can cycling safety be improved by opening all unidirectional cycle paths for cycle traffic in both directions? A theoretical examination of available literature and data.

    Science.gov (United States)

    Methorst, Rob; Schepers, Paul; Kamminga, Jaap; Zeegers, Theo; Fishman, Elliot

    2017-08-01

    Many studies have found bicycle-motor vehicle crashes to be more likely on bidirectional cycle paths than on unidirectional cycle paths because drivers do not expect cyclists riding at the right side of the road. In this paper we discuss the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions prevent this lack of expectancy and accordingly improves cycling safety. A new national standard requires careful consideration because a reversal is difficult once cyclists are used to their new freedom of route choice. We therefore explored the hypothesis using available data, research, and theories. The results show that of the length of cycle paths along distributor roads in the Netherlands, 72% is bidirectional. If drivers would become used to cyclists riding at the left side of the road, this result raises the question of why bidirectional cycle paths in the Netherlands still have a poor safety record compared to unidirectional cycle paths. Moreover, our exploration suggested that bidirectional cycle paths have additional safety problems. It increases the complexity of unsignalized intersections because drivers have to scan more directions in a short period of time. Moreover, there are some indications that the likelihood of frontal crashes between cyclists increases. We reject the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions will improve cycle safety. We recommend more attention for mitigating measures given the widespread application of bidirectional cycle paths in the Netherlands. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Performance Analysis of Hybrid Electric Vehicle over Different Driving Cycles

    Science.gov (United States)

    Panday, Aishwarya; Bansal, Hari Om

    2017-02-01

    Article aims to find the nature and response of a hybrid vehicle on various standard driving cycles. Road profile parameters play an important role in determining the fuel efficiency. Typical parameters of road profile can be reduced to a useful smaller set using principal component analysis and independent component analysis. Resultant data set obtained after size reduction may result in more appropriate and important parameter cluster. With reduced parameter set fuel economies over various driving cycles, are ranked using TOPSIS and VIKOR multi-criteria decision making methods. The ranking trend is then compared with the fuel economies achieved after driving the vehicle over respective roads. Control strategy responsible for power split is optimized using genetic algorithm. 1RC battery model and modified SOC estimation method are considered for the simulation and improved results compared with the default are obtained.

  20. Performance analysis of organic Rankine cycles using different working fluids

    Directory of Open Access Journals (Sweden)

    Zhu Qidi

    2015-01-01

    Full Text Available Low-grade heat from renewable or waste energy sources can be effectively recovered to generate power by an organic Rankine cycle (ORC in which the working fluid has an important impact on its performance. The thermodynamic processes of ORCs using different types of organic fluids were analyzed in this paper. The relationships between the ORC’s performance parameters (including evaporation pressure, condensing pressure, outlet temperature of hot fluid, net power, thermal efficiency, exergy efficiency, total cycle irreversible loss, and total heat-recovery efficiency and the critical temperatures of organic fluids were established based on the property of the hot fluid through the evaporator in a specific working condition, and then were verified at varied evaporation temperatures and inlet temperatures of the hot fluid. Here we find that the performance parameters vary monotonically with the critical temperatures of organic fluids. The values of the performance parameters of the ORC using wet fluids are distributed more dispersedly with the critical temperatures, compared with those of using dry/isentropic fluids. The inlet temperature of the hot fluid affects the relative distribution of the exergy efficiency, whereas the evaporation temperature only has an impact on the performance parameters using wet fluid.

  1. Thermodynamic assessment of impact of inlet air cooling techniques on gas turbine and combined cycle performance

    International Nuclear Information System (INIS)

    Mohapatra, Alok Ku; Sanjay

    2014-01-01

    The article is focused on the comparison of impact of two different methods of inlet air cooling (vapor compression and vapor absorption cooling) integrated to a cooled gas turbine based combined cycle plant. Air-film cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor pressure ratio, compressor inlet temperature (T i , C ), turbine inlet temperature (T i , T ), ambient relative humidity and ambient temperature on performance parameters of plant has been carried out. Optimum T i , T corresponding to maximum plant efficiency of combined cycle increases by 100 °C due to the integration of inlet air cooling. It has been observed that vapor compression cooling improves the efficiency of gas turbine cycle by 4.88% and work output by 14.77%. In case of vapor absorption cooling an improvement of 17.2% in gas cycle work output and 9.47% in gas cycle efficiency has been observed. For combined cycle configuration, however, vapor compression cooling should be preferred over absorption cooling in terms of higher plant performance. The optimum value of compressor inlet temperature has been observed to be 20 °C for the chosen set of conditions for both the inlet air cooling schemes. - Highlights: • Inlet air cooling improves performance of cooled gas turbine based combined cycle. • Vapor compression inlet air cooling is superior to vapor absorption inlet cooling. • For every turbine inlet temperature, there exists an optimum pressure ratio. • The optimum compressor inlet temperature is found to be 293 K

  2. Tools for Measuring and Improving Performance.

    Science.gov (United States)

    Jurow, Susan

    1993-01-01

    Explains the need for meaningful performance measures in libraries and the Total Quality Management (TQM) approach to data collection. Five tools representing different stages of a TQM inquiry are covered (i.e., the Shewhart Cycle, flowcharts, cause-and-effect diagrams, Pareto charts, and control charts), and benchmarking is addressed. (Contains…

  3. Comparative performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs

    Directory of Open Access Journals (Sweden)

    Sudip Bhattrai

    2013-09-01

    Full Text Available Combined-cycle pulse detonation engines are promising contenders for hypersonic propulsion systems. In the present study, design and propulsive performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs is presented. Analysis is done with respect to Mach number at two consecutive modes of operation: (1 Combined-cycle PDTE using a pulse detonation afterburner mode (PDA-mode and (2 combined-cycle PDTE in pulse detonation ramjet engine mode (PDRE-mode. The performance of combined-cycle PDTEs is compared with baseline afterburning turbofan and ramjet engines. The comparison of afterburning modes is done for Mach numbers from 0 to 3 at 15.24 km altitude conditions, while that of pulse detonation ramjet engine (PDRE is done for Mach 1.5 to Mach 6 at 18.3 km altitude conditions. The analysis shows that the propulsive performance of a turbine engine can be greatly improved by replacing the conventional afterburner with a pulse detonation afterburner (PDA. The PDRE also outperforms its ramjet counterpart at all flight conditions considered herein. The gains obtained are outstanding for both the combined-cycle PDTE modes compared to baseline turbofan and ramjet engines.

  4. Theoretical research on the performance of the transcritical ejector refrigeration cycle with various refrigerants

    International Nuclear Information System (INIS)

    Wang, F.; Li, D.Y.; Zhou, Y.

    2015-01-01

    The transcritical ejector refrigeration cycle (TERC), which has shown an attractive alternative to the ejector refrigeration systems, can better match large variable-temperature heat sources and yields higher COP. In this paper, in order to find a proper working fluid for the TERC, the performance of the TERC with CO_2 and various working fluids with low critical temperatures including R1270, R32, R143a, R125 and R115 are studied and compared. A thermodynamic model for ejector is set up to simulate the ejector by introducing the real properties of refrigerants. The results indicate that R1270 has the highest COP at the same heat source condition and medium working pressures, and is one of environment-friendly working fluids, hence R1270 is the most proper one. The COP of the transcritical cycle is higher than that of the subcritical cycle, and The effective performance coefficient COP_m of the transcritical cycle is also better. When the heater outlet temperature is increased, its system COP_m improves, but its system COP almost does not change. - Highlights: • A thermodynamic model is used to simulate the ejector with real properties. • The performance of the TERC with various refrigerants is compared. • The environment-friendly working fluid of R1270 shows the most proper one. • The COP of the transcritical cycle is higher than that of the subcritical cycle.

  5. Improving performance with accident tolerant-fuels

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Daniel S.; Muniz, Rafael O.R.; Giovedi, Claudia, E-mail: dsgomes@ipen.br, E-mail: rafael.orm@gmail.com, E-mail: claudia.giovedi@ctmsp.mar.mil.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil). Departamento de Engenharia Naval e Oceânica

    2017-07-01

    After the Fukushima reactor accident, efforts to improve risk management in nuclear operations have included the intensification of research on accident-tolerant fuels (ATFs). In this investigation, the physical properties of recently developed ATFs were compared with those of the current standard fuel, UO{sub 2} - Zr. The goals for innovative fuel design include a rigorous characterization of the thermal, mechanical, and chemical considerations. The intentions are to lengthen the burnup cycle, raise the power density, and improve safety. Fuels must have a high uranium density - above that supported by UO{sub 2} - and possess a coating that exhibits better oxidation resistance than Zircaloys. ATFs such as U{sub 3}Si{sub 2}, UN, and UC contain a higher uranium density and thermal conductivity than UO{sub 2}, providing significant benefits. The ideal combination of fuel and cladding must increase performance in a loss-of-coolant accident. However, U{sub 3}Si{sub 2}, UN, and UC have a disadvantage; their respective swelling rates are higher than that of UO{sub 2}. These ATFs also have thermal conductivities approximately four times higher than that of UO{sub 2}. A study was conducted investigating the hydrogen generated by the oxidation of zirconium alloys in contact with steam using cladding options such as Fe-Cr-Al and silicon carbide. It was confirmed that ferritic alloys offer a better response under severe conditions, because of their mechanical properties as creep rate. The findings of this study indicate that advanced fuels should replace UO{sub 2} - Zr as the fuel system of choice. (author)

  6. Methodological approach to organizational performance improvement process

    OpenAIRE

    Buble, Marin; Dulčić, Želimir; Pavić, Ivan

    2017-01-01

    Organizational performance improvement is one of the fundamental enterprise tasks. This especially applies to the case when the term “performance improvement” implies efficiency improvement measured by indicators, such as ROI, ROE, ROA, or ROVA/ROI. Such tasks are very complex, requiring implementation by means of project management. In this paper, the authors propose a methodological approach to improving the organizational performance of a large enterprise.

  7. Methodological approach to organizational performance improvement process

    Directory of Open Access Journals (Sweden)

    Marin Buble

    2001-01-01

    Full Text Available Organizational performance improvement is one of the fundamental enterprise tasks. This especially applies to the case when the term “performance improvement” implies efficiency improvement measured by indicators, such as ROI, ROE, ROA, or ROVA/ROI. Such tasks are very complex, requiring implementation by means of project management. In this paper, the authors propose a methodological approach to improving the organizational performance of a large enterprise.

  8. SRF Performance of CEBAF After Thermal Cycle to Ambient Temperature

    International Nuclear Information System (INIS)

    Robert Rimmer; Jay Benesch; Joseph Preble; Charles Reece

    2005-01-01

    In September 2003, in the wake of Hurricane Isabel, JLab was without power for four days after a tree fell on the main power lines feeding the site. This was long enough to lose insulating vacuum in the cryomodules and cryogenic systems resulting in the whole accelerator warming up and the total loss of the liquid helium inventory. This thermal cycle stressed many of the cryomodule components causing several cavities to become inoperable due to helium to vacuum leaks. At the same time the thermal cycle released years of adsorbed gas from the cold surfaces. Over the next days and weeks this gas was pumped away, the insulating vacuum was restored and the machine was cooled back down and re-commissioned. In a testament to the robustness of SRF technology, only a small loss in energy capability was apparent, although individual cavities had quite different field-emission characteristics compared to before the event. In Summer 2004 a section of the machine was again cycled to room temperature during the long maintenance shutdown. We report on the overall SRF performance of the machine after these major disturbances and on efforts to characterize and optimize the new behavior for high-energy running

  9. Health technology assessment to improve the medical equipment life cycle management.

    Science.gov (United States)

    Margotti, Ana E; Ferreira, Filipa B; Santos, Francisco A; Garcia, Renato

    2013-01-01

    Health technology assessment (HTA) is a tool to support decision making that is intended to assist healthcare managers in their strategic decisions. The use of HTA as a tool for clinical engineering is especially relevant in the domain of the medical equipment once it could improve the performance of the medical equipment. It would be done by their systematically evaluation in several aspects, in their life cycle. In Brazil, the Institute of Biomedical Engineering (IEB-UFSC) through the clinical engineering area has been working on the development of methodologies and improvements on HTA for medical equipment. Therefore, this paper presents the effort to create specific methodologies that will improve the dissemination of HTA, focusing on incorporation and utilization phase of the medical equipment life cycle. This will give a better support to the decision makers in the management of the health care system.

  10. Performance of a Supercritical CO2 Bottoming Cycle for Aero Applications

    Directory of Open Access Journals (Sweden)

    Florian Jacob

    2017-03-01

    Full Text Available By 2050, the evolutionary approach to aero engine research may no longer provide meaningful returns on investment, whereas more radical approaches to improving thermal efficiency and reducing emissions might still prove cost effective. One such radical concept is the addition of a secondary power cycle that utilizes the otherwise largely wasted residual heat in the core engine’s exhaust gases. This could provide additional shaft power. Supercritical carbon dioxide closed-circuit power cycles are currently being investigated primarily for stationary power applications, but their high power density and efficiency, even for modest peak cycle temperatures, makes them credible bottoming cycle options for aero engine applications. Through individual geometric design and performance studies for each of the bottoming cycle’s major components, it was determined that a simple combined cycle aero engine could offer a 1.9% mission fuel burn benefit over a state-of-the-art geared turbofan for the year 2050. However, the even greater potential of more complex systems demands further investigation. For example, adding inter-turbine reheat (ITR to the combined cycle is predicted to significantly improve the fuel burn benefit.

  11. Method for controlling start-up and steady state performance of a closed split flow recompression brayton cycle

    Science.gov (United States)

    Pasch, James Jay

    2017-02-07

    A method of resolving a balanced condition that generates control parameters for start-up and steady state operating points and various component and cycle performances for a closed split flow recompression cycle system. The method provides for improved control of a Brayton cycle thermal to electrical power conversion system. The method may also be used for system design, operational simulation and/or parameter prediction.

  12. Performance investigation of an advanced multi-effect adsorption desalination (MEAD) cycle

    KAUST Repository

    Thu, Kyaw

    2015-12-01

    This article presents the development of an advanced adsorption desalination system with quantum performance improvement. The proposed multi-effect adsorption desalination (MEAD) cycle utilizes a single heat source i.e., low-temperature hot water (as low as 55°C). Passive heating of the feed water (no direct heating) is adopted using total internal heat recovery from the kinetic energy of desorbed vapor and water vapor uptake potential of the adsorbent. Thus, the evaporation in the MEAD cycle ensues at low temperatures ranging from 35°C to 7°C yet providing significantly high performance ratio. The energy from the regenerated vapor is recovered for multiple evaporation/condensation of saline water by a water-run-around circuit between the top brine temperature (TBT) effect and the AD condenser. The adsorbent material is the hydrophilic mesoporous silica gel with high pore surface area. Numerical simulation for such a cycle is developed based on experimentally verified model extending to multi-effect cycle. The system is investigated under several operation conditions such as cycle time allocation, heat source temperature and the number of intermediate effects. It is observed that most of the evaporating-condensing effects operate at low temperature i.e., below 35°C as opposed to conventional multi-effect distillation (MED) cycle. For a MEAD cycle with 7 intermediate effects, the specific water production rate, the performance ratio and the gain output ratio are found to be 1.0m3/htonne of silica gel, 6.3 and 5.1, respectively. Low scaling and fouling potentials being evaporation at low temperatures yet high recovery ratio makes the cycle suitable for effectively and efficiently handling highly concentrated feed water such as produced water, brine rejected from other desalination plants and zero liquid discharge (ZLD) system. © 2015 Elsevier Ltd.

  13. Performance investigation of an advanced multi-effect adsorption desalination (MEAD) cycle

    International Nuclear Information System (INIS)

    Thu, Kyaw; Kim, Young-Deuk; Shahzad, Muhammad Wakil; Saththasivam, Jayaprakash; Ng, Kim Choon

    2015-01-01

    Highlights: • Multi-effect adsorption desalination (MEAD) cycle for improved performance. • Passive heating of saline water recovering kinetic energy from desorption. • All effects operate at low temperature i.e., below 35 °C unlike conventional cycle. • High PR (6.3) with low temperature heat source. • Analyzed using p–T–q diagram tracking the temperatures and uptakes. - Abstract: This article presents the development of an advanced adsorption desalination system with quantum performance improvement. The proposed multi-effect adsorption desalination (MEAD) cycle utilizes a single heat source i.e., low-temperature hot water (as low as 55 °C). Passive heating of the feed water (no direct heating) is adopted using total internal heat recovery from the kinetic energy of desorbed vapor and water vapor uptake potential of the adsorbent. Thus, the evaporation in the MEAD cycle ensues at low temperatures ranging from 35 °C to 7 °C yet providing significantly high performance ratio. The energy from the regenerated vapor is recovered for multiple evaporation/condensation of saline water by a water-run-around circuit between the top brine temperature (TBT) effect and the AD condenser. The adsorbent material is the hydrophilic mesoporous silica gel with high pore surface area. Numerical simulation for such a cycle is developed based on experimentally verified model extending to multi-effect cycle. The system is investigated under several operation conditions such as cycle time allocation, heat source temperature and the number of intermediate effects. It is observed that most of the evaporating–condensing effects operate at low temperature i.e., below 35 °C as opposed to conventional multi-effect distillation (MED) cycle. For a MEAD cycle with 7 intermediate effects, the specific water production rate, the performance ratio and the gain output ratio are found to be 1.0 m"3/h tonne of silica gel, 6.3 and 5.1, respectively. Low scaling and fouling

  14. Performance analysis of a novel heat pump type air conditioner coupled with a liquid dehumidification/humidification cycle

    International Nuclear Information System (INIS)

    Cai, Dehua; Qiu, Chengbo; Zhang, Jiazheng; Liu, Yue; Liang, Xiao; He, Guogeng

    2017-01-01

    Graphical abstract: Cycle performance of a small scale heat pump type air conditioner coupled with a liquid desiccant/humidification cycle has been theoretically and experimentally evaluated by the present study. The liquid desiccant and humidification cycle is driven by the exhaust heat of the compressor. LDAC not only greatly improves the indoor air quality by controlling the humidity and temperature independently, but also decrease the electrical energy consumption of the traditional air conditioner. Parametric analysis on cycle performance of the present cycle based on both theoretical and experimental methods are carried out. - Highlights: • Hybrid cycle consists of refrigeration cycle and liquid desiccant cycle is proposed. • Liquid desiccant cycle is driven by the compressor exhaust heat. • Theoretical and experimental studies on cycle performance are provided. • Energy consumption decreases about 22.64% compared with the conventional one. - Abstract: In recent years, liquid desiccant air-conditioning system (LDAC) has shown a great potential alternative to the conventional vapor compression systems. LDAC not only greatly improves the indoor air quality by controlling the humidity and temperature independently, but also deceases the electrical energy consumption of the conventional air conditioner. In this work, the liquid desiccant and humidification cycle is driven by the exhaust heat of the compressor. Cycle performance of a small-scale heat pump type air conditioner coupled with a liquid desiccant/humidification cycle has been theoretically and experimentally evaluated by the present study. Parametric analysis on cycle performance of the present cycle is carried out through both theoretical and experimental methods, and lithium chloride aqueous solution is used as the working fluid of the solution cycle. The thermodynamic analysis results show that while the evaporating temperature of the present cycle increases to 15 °C, the energy consumption

  15. Effect of combined β-alanine and sodium bicarbonate supplementation on cycling performance.

    Science.gov (United States)

    Bellinger, Phillip M; Howe, Samuel T; Shing, Cecilia M; Fell, James W

    2012-08-01

    The purpose of this study was to investigate the effects of 28 d of β-alanine supplementation on 4-min cycling time trial performance and to determine whether there was an additive effect of combined β-alanine and sodium bicarbonate (NaHCO3) supplementation on high-intensity cycling performance. Fourteen highly trained cyclists (mean ± SD: age = 25.4 ± 7.2 yr, mass = 71.1 ± 7.1 kg, V˙O(2max) = 66.6 ± 5.7 mL·kg·min) supplemented for 28 d with β-alanine (65 mg·kg body mass each day) or placebo. A maximal 4-min bout of cycling was performed before supplementation (baseline) and twice after supplementation: after ingestion of NaHCO3 (300 mg·kg body mass) and ingestion of a placebo using a randomized crossover design with 2 d between trials. Blood pH and HCO3 concentration were determined before loading (postsupplementation trials) and at pretest and posttest. In the acute NaHCO3 loading trials, blood pH and HCO3 were elevated from before loading to pretest, and the magnitude of the change in HCO3 from pretest to posttest was significantly greater compared with the acute placebo loading trial (P < 0.001). Average power output in the 4-min cycling performance trial was increased in placebo + NaHCO3 (+3.1% ± 1.8%) and β-alanine + NaHCO3 (+3.3% ± 3.0%) compared with baseline (P < 0.05). β-alanine + placebo did not significantly improve average power output compared with baseline (+1.6% ± 1.7%, P = 0.20); however, magnitude-based inferences demonstrated that β-alanine + placebo was associated with a 37% likelihood of producing average power improvements. In trained cyclists, β-alanine supplementation did not significantly improve 4-min cycling performance; however, there may be a small meaningful improvement in performance. Acute NaHCO3 supplementation significantly improved 4-min cycling performance. There seemed to be a minimal additive effect of combined β-alanine and NaHCO3 supplementation.

  16. Environmental Performance of Kettle Production: Product Life Cycle Assessment

    Science.gov (United States)

    Marcinkowski, Andrzej; Zych, Krzysztof

    2017-12-01

    The main objective of this paper is to compare the environmental impact caused by two different types of water boiling processes. The aim was achieved thanks to product life cycle assessment (LCA) conducted for stovetop and electric kettles. A literature review was carried out. A research model was worked out on the basis of data available in literature as well as additional experiments. In order to have a better opportunity to compare LCA results with reviewed literature, eco-indicator 99 assessment method was chosen. The functional unit included production, usage and waste disposal of each product (according to from cradle to grave approach) where the main function is boiling 3360 l of water during 4-year period of time. A very detailed life cycle inventory was carried out. The mass of components was determined with accuracy of three decimal places (0.001 g). The majority of environmental impact is caused by electricity or natural gas consumption during usage stage: 92% in case of the electric and kettle and 99% in case of stovetop one. Assembly stage contributed in 7% and 0.8% respectively. Uncertainty and sensitivity analyses took into consideration various waste scenario patterns as well as demand for transport. Environmental impact turned out to be strongly sensitive to a chosen pattern of energy delivery (electricity mix) which determined final comparison results. Basing on LCA results, some improvements of products were suggested. The boiling time optimization was pointed out for electric kettle's efficiency improvement. Obtained results can be used by manufacturers in order to improve their eco-effectiveness. Moreover, conclusions following the research part can influence the future choices of home appliances users.

  17. ENVIRONMENTAL PERFORMANCE OF KETTLE PRODUCTION: PRODUCT LIFE CYCLE ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Andrzej MARCINKOWSKI

    2017-10-01

    Full Text Available The main objective of this paper is to compare the environmental impact caused by two different types of water boiling processes. The aim was achieved thanks to product life cycle assessment (LCA conducted for stovetop and electric kettles. A literature review was carried out. A research model was worked out on the basis of data available in literature as well as additional experiments. In order to have a better opportunity to compare LCA results with reviewed literature, eco-indicator 99 assessment method was chosen. The functional unit included production, usage and waste disposal of each product (according to from cradle to grave approach where the main function is boiling 3360 l of water during 4- year period of time. A very detailed life cycle inventory was carried out. The mass of components was determined with accuracy of three decimal places (0.001 g. The majority of environmental impact is caused by electricity or natural gas consumption during usage stage: 92% in case of the electric and kettle and 99% in case of stovetop one. Assembly stage contributed in 7% and 0.8% respectively. Uncertainty and sensitivity analyses took into consideration various waste sce-nario patterns as well as demand for transport. Environmental impact turned out to be strongly sensitive to a chosen pattern of energy delivery (electricity mix which determined final comparison results. Basing on LCA results, some im-provements of products were suggested. The boiling time optimization was pointed out for electric kettle's efficiency improvement. Obtained results can be used by manufacturers in order to improve their eco-effectiveness. Moreover, conclusions following the research part can influence the future choices of home appliances users.

  18. Peer groups and operational cycle enhancements to the performance indicator report

    International Nuclear Information System (INIS)

    Stromberg, H.M.; DeHaan, M.S.; Gentillon, C.D.; Wilson, G.E.; Vanden Heuvel, L.N.

    1992-01-01

    Accurate performance evaluation and plant trending by the performance indicator program are integral parts of monitoring the operation of commercial nuclear power plants. The presentations of the NRC/AEOD performance indicator program have undergone a number of enhancements. The diversity of the commercial nuclear plants, coupled with continued improvements in the performance indicator program, has resulted in the evaluation of plants in logical peer groups and highlighted the need to evaluate the impact of plant operational conditions on the performance indicators. These enhancements allow a more-meaningful evaluation of operating commercial nuclear power plant performance. This report proposes methods to enhance the presentation of the performance indicator data by analyzing the data in logical peer groups and displaying the performance indicator data based on the operational status of the plants. Previously, preliminary development of the operational cycle displays of the performance indicator data was documented. This report extends the earlier findings and presents the continued development of the peer groups and operational cycle trend and deviation data and displays. This report describes the peer groups and enhanced PI data presentations by considering the operational cycle phase breakdowns, calculation methods, and presentation methods

  19. Comparative analysis of thermodynamic performance and optimization of organic flash cycle (OFC) and organic Rankine cycle (ORC)

    International Nuclear Information System (INIS)

    Lee, Ho Yong; Park, Sang Hee; Kim, Kyoung Hoon

    2016-01-01

    A comparative thermodynamic performance and optimization analysis of basic organic flash cycle (OFCB), organic flash cycle with two-phase expander (OFCT), and organic Rankine cycle (ORC) activated by low-temperature sensible energy is carried out in the subcritical pressure regions. The three substances of R245fa, R123, and o-xylene are considered as the working fluids. Effects of cycle type, working fluid, and evaporation and source temperatures are systemically investigated on the system performance such as net power production, thermal and exergy efficiencies, and exergy destruction ratios at each component of the systems. Results show that the cycle type or working fluid which shows optimum performance depends on the source temperature, and organic flash cycle shows a potential for efficient recovery of low grade energy source.

  20. Performance and environment as objectives in multi-criterion optimization of steam injected gas turbine cycles

    International Nuclear Information System (INIS)

    Kayadelen, Hasan Kayhan; Ust, Yasin

    2014-01-01

    Rapidly growing demand for gas turbines promotes research on their performance improvement and reducing their exhaust pollutants. Even small increments in net power or thermal efficiency and small changes in pollutant emissions have become significant concerns for both new designs and cycle modifications. To fulfill these requirements an accurate performance evaluation method which enables to see the effects on the exhaust gas composition is an important necessity. To fill this gap, a thermo-ecologic performance evaluation approach for gas turbine cycles with chemical equilibrium approximation which enables performance and environmental aspects to be considered simultaneously, is presented in this work. Steam injection is an effective modification to boost power and limit NO x emissions for gas turbine systems. Steam injection also increases thermal efficiency so less fuel is burnt to maintain the same power output. Because of its performance related and environmental advantages, presented approach is applied on the steam injected gas turbine cycle and a precise multi-criterion optimization is carried out for varying steam injection, as well as equivalence and pressure ratios. Irreversibilities and pressure losses are also considered. Effects of each parameter on the net work and thermal efficiency as well as non-equilibrium NO x and CO emissions are demonstrated. Precision improvement of the presented thermo-ecological model is shown and two main concerns; constant turbine inlet condition for higher net work output and constant net work output condition for lower fuel consumption are compared. - Highlights: • A thermodynamically precise performance estimation tool for GT cycles is presented. • STIG application is provided to show its flexibility for any GT cycle and diluents. • Constant TIT and net work output conditions have been compared and discussed. • The model provides results to evaluate economic and environmental aspects together. • It provides a

  1. Improvement of supercritical CO2 Brayton cycle using binary gas mixture

    International Nuclear Information System (INIS)

    Jeong, Woo Seok

    2011-02-01

    A Sodium-cooled Fast Reactor (SFR) is one of the strongest candidates for the next generation nuclear reactor. However, the conventional design of a SFR concept with an indirect Rankine cycle is inevitably subjected to a sodium-water reaction. To prevent hazardous situation caused by sodium-water reaction, the SFR with Brayton cycle using Supercritical Carbon dioxide (S-CO 2 cycle) as a working fluid can be an alternative approach. The S-CO 2 Brayton cycle is more sensitive to the critical point of working fluids than other Brayton cycles. This is because compressor work significantly decreases at slightly above the critical point due to high density near the boundary between the supercritical state and the subcritical state. For this reason, the minimum temperature and pressure of cycle are just above the CO 2 critical point. The critical point acts as a limitation of the lowest operating condition of the cycle. In general, lowering the rejection temperature of a thermodynamic cycle increases the efficiency and thus, changing the critical point of CO 2 can result in an improvement of the total cycle efficiency with the same cycle layout. Modifying the critical point of the working fluid can be done by adding other gases to CO 2 . The direction and range of the CO 2 critical point variation depends on the mixed component and its amount. In particular, chemical reactivity of the gas mixture itself and the gas mixture with sodium at high temperatures are of interest. To modify the critical point of the working fluid, several gases were chosen as candidates by which chemical stability with sodium within the interested range of cycle operating condition was assured: CO 2 was mixed with N 2 , O 2 , He, Ar and Xe. To evaluate the effect of shifting the critical point and changes in the properties of the S-CO 2 Brayton cycle, a supercritical Brayton cycle analysis code connected with the REFPROP program from the NIST was developed. The developed code is for evaluating

  2. Identifying improvement potentials in cement production with life cycle assessment.

    Science.gov (United States)

    Boesch, Michael Elias; Hellweg, Stefanie

    2010-12-01

    Cement production is an environmentally relevant process responsible for 5% of total anthropogenic carbon dioxide emissions and 7% of industrial fuel use. In this study, life cycle assessment is used to evaluate improvement potentials in the cement production process in Europe and the USA. With a current fuel substitution rate of 18% in Europe and 11% in the USA, both regions have a substantial potential to reduce greenhouse gas emissions and save virgin resources by further increasing the coprocessing of waste fuels. Upgrading production technology would be particularly effective in the USA where many kiln systems with very low energy efficiency are still in operation. Using best available technology and a thermal substitution rate of 50% for fuels, greenhouse gas emissions could be reduced by 9% for Europe and 18% for the USA per tonne of cement. Since clinker production is the dominant pollution producing step in cement production, the substitution of clinker with mineral components such as ground granulated blast furnace slag or fly ash is an efficient measure to reduce the environmental impact. Blended cements exhibit substantially lower environmental footprints than Portland cement, even if the substitutes feature lower grindability and require additional drying and large transport distances. The highest savings in CO(2) emissions and resource consumption are achieved with a combination of measures in clinker production and cement blending.

  3. Improving geothermal power plants with a binary cycle

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  4. Double Girder Bridge Crane with Double Cycling: Scheduling Strategy and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2014-01-01

    Full Text Available This paper introduces a novel quay crane design, double girder bridge crane (DGBC. DGBC is capable of handling containers of two adjacent bays simultaneously, avoiding crane collisions, saving travelling and reposition cost, and eventually improving terminal efficiency. This problem is formulated as a resource-constrained project scheduling with objective to minimize the maximum completion time. A two-stage heuristic algorithm is proposed in which an operating sequences on each bay is obtained by double cycling, and the integrated timetable for both bays is constructed by solving resource conflicts using the proposed minimum cost strategy. We examine effectiveness and performance of applying DGBC with double cycling. A case study is presented to illustrate how DGBC works with the two-stage method. Three extreme cases with respective conflict types are investigated to develop the performance bounds of DGBC with double cycling. The results show that DGBC can significantly improve terminal productivity, and outperforms single girder crane in both makespan and the lift operation percentage. The highest DGBC efficiency does not require maximum double cycles in two bay schedules; rather the integrated timetable for two bays is the main contribution to the DGBC performance as it yields better cooperation between two spreaders and the driver.

  5. Can FES-augmented active cycling training improve locomotion in post-acute elderly stroke patients?

    Directory of Open Access Journals (Sweden)

    Elisabetta Peri

    2016-06-01

    Full Text Available Recent studies advocated the use of active cycling coupled with functional electrical stimulation to induce neuroplasticity and enhance functional improvements in stroke adult patients. The aim of this work was to evaluate whether the benefits induced by such a treatment are superior to standard physiotherapy. A single-blinded randomized controlled trial has been performed on post-acute elderly stroke patients. Patients underwent FES-augmented cycling training combined with voluntary pedaling or standard physiotherapy. The intervention consisted of fifteen 30-minutes sessions carried out within 3 weeks. Patients were evaluated before and after training, through functional scales, gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy group. Sixteen patients completed the training. After treatment, a general improvement of all clinical scales was obtained for both groups. Only the mechanical efficiency highlighted a group effect in favor of the experimental group. Although a group effect was not found for any other cycling or gait parameters, the experimental group showed a higher percentage of change with respect to the control group (e.g. the gait velocity was improved of 35.4% and 25.4% respectively, and its variation over time was higher than minimal clinical difference for the experimental group only. This trend suggests that differences in terms of motor recovery between the two groups may be achieved increasing the training dose. In conclusion, this study, although preliminary, showed that FES-augmented active cycling training seems to be effective in improving cycling and walking ability in post-acute elderly stroke patients. A higher sample size is required to confirm results.

  6. Human performance improvement for nuclear power plants

    International Nuclear Information System (INIS)

    2005-01-01

    The IAEA assists NPP operating organizations to improve plant performance through a focus on human performance improvement in areas like organizational and leadership development, senior management decision making, organization and management of HPI programmes including tools needed for effective HPI implementation, safety culture enhancement, knowledge management, personnel selection and staffing, career development, training and development, work design, scheduling and conditions, procedure and other job-aid development and use, effective communications, human performance monitoring, motivation. Many NPP operating organizations in Member States, are not yet achieving the full potential of their NPP technology/equipment regarding safety, operational or economic performance due to human performance weaknesses. The IAEA's HPI (Human Performance Improvement) services provide a means for these organizations to efficiently and effectively learn from international experts and the experiences of others in improving plant performance through human performance improvements. NPP operating organizations can benefit from these services in a number of ways, including requesting a national project, participating in a regional project, or requesting an assist visit. The types of activities provided through these services include assistance in benchmarking practices of successful organizations, providing information exchange and reviews of current practices through assist missions, conducting workshops on focused human performance topics, evaluating current human performance methods, including assistance in implementing self assessment programmes and providing support to safety culture enhancement programmes based on self-assessment

  7. Improving performance on core processes of care.

    Science.gov (United States)

    Austin, John Matthew; Pronovost, Peter J

    2016-06-01

    This article describes the recent literature on using extrinsic and intrinsic motivators to improve performance on core processes of care, highlighting literature that describes general frameworks for quality improvement work. The literature supporting the effectiveness of extrinsic motivators to improve quality is generally positive for public reporting of performance, with mixed results for pay-for-performance. A four-element quality improvement framework developed by The Armstrong Institute at Johns Hopkins Medicine was developed with intrinsic motivation in mind. The clear definition and communication of goals are important for quality improvement work. Training clinicians in improvement science, such as lean sigma, teamwork, or culture change provides clinicians with the skills they need to drive the improvement work. Peer learning communities offer the opportunity for clinicians to engage with each other and offer support in their work. The transparent reporting of performance helps ensure accountability of performance ranging from individual clinicians to governance. Quality improvement work that is led by and engages clinicians offers the opportunity for the work to be both meaningful and sustainable. The literature supports approaching quality improvement work in a systematic way, including the key elements of communication, infrastructure building, training, transparency, and accountability.

  8. Advanced codes and methods supporting improved fuel cycle economics - 5493

    International Nuclear Information System (INIS)

    Curca-Tivig, F.; Maupin, K.; Thareau, S.

    2015-01-01

    AREVA's code development program was practically completed in 2014. The basic codes supporting a new generation of advanced methods are the followings. GALILEO is a state-of-the-art fuel rod performance code for PWR and BWR applications. Development is completed, implementation started in France and the U.S.A. ARCADIA-1 is a state-of-the-art neutronics/ thermal-hydraulics/ thermal-mechanics code system for PWR applications. Development is completed, implementation started in Europe and in the U.S.A. The system thermal-hydraulic codes S-RELAP5 and CATHARE-2 are not really new but still state-of-the-art in the domain. S-RELAP5 was completely restructured and re-coded such that its life cycle increases by further decades. CATHARE-2 will be replaced in the future by the new CATHARE-3. The new AREVA codes and methods are largely based on first principles modeling with an extremely broad international verification and validation data base. This enables AREVA and its customers to access more predictable licensing processes in a fast evolving regulatory environment (new safety criteria, requests for enlarged qualification databases, statistical applications, uncertainty propagation...). In this context, the advanced codes and methods and the associated verification and validation represent the key to avoiding penalties on products, on operational limits, or on methodologies themselves

  9. Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns

    International Nuclear Information System (INIS)

    Clark, E.A.

    1992-01-01

    Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (AHL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns

  10. Modified-open fuel cycle performance with breed-and-burn advanced reactor concepts

    International Nuclear Information System (INIS)

    Heidet, Florent; Kim, Taek K.; Taiwo, Temitope A.

    2011-01-01

    Recent advances in fast reactor designs enable significant increase in the uranium utilization in an advanced fuel cycle. The category of fast reactors, collectively termed breed-and-burn reactor concepts, can use a large amount of depleted uranium as fuel without requiring enrichment with the exception of the initial core critical loading. Among those advanced concepts, some are foreseen to operate within a once-through fuel cycle such as the Traveling Wave Reactor, CANDLE reactor or Ultra-Long Life Fast Reactor, while others are intended to operate within a modified-open fuel cycle, such as the Breed-and-Burn reactor and the Energy Multiplier Module. This study assesses and compares the performance of the latter category of breed-and-burn reactors at equilibrium state. It is found that the two reactor concepts operating within a modified-open fuel cycle can significantly improve the sustainability and security of the nuclear fuel cycle by decreasing the uranium resources and enrichment requirements even further than the breed-and-burn core concepts operating within the once-through fuel cycle. Their waste characteristics per unit of energy are also found to be favorable, compared to that of currently operating PWRs. However, a number of feasibility issues need to be addressed in order to enable deployment of these breed-and-burn reactor concepts. (author)

  11. Numerical simulation and performance investigation of an advanced adsorption desalination cycle

    KAUST Repository

    Thu, Kyaw

    2013-01-01

    Low temperature waste heat-driven adsorption desalination (AD) cycles offer high potential as one of the most economically viable and environmental-friendly desalination methods. This article presents the development of an advanced adsorption desalination cycle that employs internal heat recovery between the evaporator and the condenser, utilizing an encapsulated evaporator-condenser unit for effective heat transfer. A simulation model has been developed based on the actual sorption characteristics of the adsorbent-adsorbate pair, energy and mass balances applied to the components of the AD cycle. With an integrated design, the temperature in the evaporator and the vapor pressurization of the adsorber are raised due to the direct heat recovery from the condenser, resulting in the higher water production rates, typically improved by as much as three folds of the conventional AD cycle. In addition, the integrated design eliminates two pumps, namely, the condenser cooling water and the chilled water pumps, lowering the overall electricity consumption. The performance of the cycle is analyzed at assorted heat source and cooling water temperatures, and different cycle times as well as the transient heat transfer coefficients of the evaporation and condensation. © 2012 Elsevier B.V.

  12. Software life cycle dynamic simulation model: The organizational performance submodel

    Science.gov (United States)

    Tausworthe, Robert C.

    1985-01-01

    The submodel structure of a software life cycle dynamic simulation model is described. The software process is divided into seven phases, each with product, staff, and funding flows. The model is subdivided into an organizational response submodel, a management submodel, a management influence interface, and a model analyst interface. The concentration here is on the organizational response model, which simulates the performance characteristics of a software development subject to external and internal influences. These influences emanate from two sources: the model analyst interface, which configures the model to simulate the response of an implementing organization subject to its own internal influences, and the management submodel that exerts external dynamic control over the production process. A complete characterization is given of the organizational response submodel in the form of parameterized differential equations governing product, staffing, and funding levels. The parameter values and functions are allocated to the two interfaces.

  13. Resveratrol Improves Cell Cycle Arrest in Chronic Prostatitis Rats, by C-kit/SCF Suppression.

    Science.gov (United States)

    He, Yi; Zeng, Huizhi; Yu, Yang; Zhang, Jiashu; Zeng, Xiaona; Gong, Fengtao; Liu, Qi; Yang, Bo

    2017-08-01

    Chronic prostatitis (CP) with complex pathogenesis is difficult for treatment. c-kit has been associated with the control of cell proliferation of prostate cells. This study aims to evaluate the role of resveratrol, an activator of Sirt1, in regulating the expression of c-kit in CP and investigate the consequent effects on cell cycle. Rat model of CP was established through subcutaneous injections of diphtheria-pertussis-tetanus vaccine and subsequently treated with resveratrol. Hematoxylin and eosin staining was performed to identify the histopathological changes in prostates. Western blotting and immunohistochemical staining examined the expression level of c-kit, stem cell factor (SCF), Sirt1, and cell cycle-associated proteins. The model group exhibited severe diffuse chronic inflammation, characterized by leukocyte infiltration and papillary frond protrusion into the gland cavities, and a notable increase in prostatic epithelial height. Gland lumen diameter was also significantly smaller; the activity of c-kit/SCF in the CP rats was increased significantly compared to the control group. Meanwhile, the cell cycle proteins are dysregulated significantly in CP rats. Resveratrol treatment significantly improved these factors by Sirt1 activation. Dysregulation of cell cycle was involved in the pathological processes of CP, which was improved after resveratrol treatment by the downregulation of c-kit/SCF by activating Sirt1.

  14. Influence of Fixed Temperature of Chilled Water Outlet Setting toward Performance of Chiller Absorbtion with Two Level Heating Cycle Method

    Directory of Open Access Journals (Sweden)

    I Gusti Agung Bagus Wirajati

    2012-11-01

    Full Text Available The study investigated the performance of re-heat two stage cycle. This paper presents the working principle and theexperimental results of the reheat two stage adsorption cycle. The performance of the cycle was evaluated under differentheat source temperature and mass recovery time. Coefficient of performance (COP and cooling capacity have beencalculated to analyze the influences of experimental conditions. The experimental results shown in both COP and coolingcapacity increased along with heat source temperature increased, and mass recovery time is very effective to improve theperformance without increasing heat source temperature.

  15. Improving the cycling stability of silicon nanowire anodes with conducting polymer coatings

    KAUST Repository

    Yao, Yan; Liu, Nian; McDowell, Matthew T.; Pasta, Mauro; Cui, Yi

    2012-01-01

    For silicon nanowires (Si NWs) to be used as a successful high capacity lithium-ion battery anode material, improvements in cycling stability are required. Here we show that a conductive polymer surface coating on the Si NWs improves cycling stability; coating with PEDOT causes the capacity retention after 100 charge-discharge cycles to increase from 30% to 80% over bare NWs. The improvement in cycling stability is attributed to the conductive coating maintaining the mechanical integrity of the cycled Si material, along with preserving electrical connections between NWs that would otherwise have become electrically isolated during volume changes. © 2012 The Royal Society of Chemistry.

  16. Part-load performance of a high temperature Kalina cycle

    DEFF Research Database (Denmark)

    Modi, Anish; Andreasen, Jesper Graa; Kærn, Martin Ryhl

    2015-01-01

    The Kalina cycle has recently seen increased interest as an alternative to the conventional steam Rankine cycle. The cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine...

  17. Performance improvement program: goals and experience

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, F. [Point Lepreau Generating Station, Maces Bay, New Brunswick (Canada)

    2015-07-01

    Following long 54 month refurbishment outage at Point Lepreau Generating Station, operational performance had fallen below industry standards in a number of areas. Leadership development and succession planning had stalled. Operational focus was low primarily due to the construction focus during refurbishment. Condition of balance of plant was poor including several long standing deficiencies. In order to improve performance, the site implemented a framework based on INPO 12-011: Focus on Improving Behaviours; Set common goals and demonstrate results; Align and engage the organization; Drive to achieve high levels of performance and sustain performance.

  18. Performance improvement program: goals and experience

    International Nuclear Information System (INIS)

    Guglielmi, F.

    2015-01-01

    Following long 54 month refurbishment outage at Point Lepreau Generating Station, operational performance had fallen below industry standards in a number of areas. Leadership development and succession planning had stalled. Operational focus was low primarily due to the construction focus during refurbishment. Condition of balance of plant was poor including several long standing deficiencies. In order to improve performance, the site implemented a framework based on INPO 12-011: Focus on Improving Behaviours; Set common goals and demonstrate results; Align and engage the organization; Drive to achieve high levels of performance and sustain performance.

  19. Does Education Reform Improve Job Performance

    National Research Council Canada - National Science Library

    Wenger, J

    2003-01-01

    .... Examining military personnel data, which is a highly detailed source of information for recent high school graduate's performance, we find that the quality of Navy recruits improved during the 1990...

  20. Performance analysis of solar parabolic trough collectors driven combined supercritical CO2 and organic Rankine cycle

    Directory of Open Access Journals (Sweden)

    Harwinder Singh

    2018-06-01

    Full Text Available In this paper, attempts have been made on the detailed energy and exergy analysis of solar parabolic trough collectors (SPTCs driven combined power plant. The combination of supercritical CO2 (SCO2 cycle and organic Rankine cycle (ORC integrated with SPTCs has been used to produce power, in which SCO2 cycle and ORC are arranged as a topping and bottoming cycle. Five organic working fluids like R134a, R1234yf, R407c, R1234ze, and R245fa were selected for a low temperature bottoming ORC. Five key exergetic parameters such as exergetic efficiency, exergy destruction rate, fuel depletion ratio, irreversibility ratio, and improvement potential were also examined. It was revealed that exergetic and thermal efficiency of all the combined cycles enhances as the direct normal irradiance increases from 0.5 kW/m2 to 0.95 kW/m2. As can be seen, R407c combined cycle has the maximum exergetic as well as thermal efficiency which is around 78.07% at 0.95 kW/m2 and 43.49% at 0.95 kW/m2, respectively. Alternatively, the R134a and R245fa combined cycle yields less promising results with the marginal difference in their performance. As inferred from the study that SCO2 turbine and evaporator has a certain amount of exergy destruction which is around 9.72% and 8.54% of the inlet exergy, and almost 38.10% of the total exergy destruction in case of R407c combined cycle. Moreover, the maximum amount of exergy destructed by the solar collector field which is more than 25% of the solar inlet exergy and around 54% of the total destructed exergy. Finally, this study concludes that R407c combined cycle has a minimum fuel depletion ratio of 0.2583 for a solar collector and possess the highest power output of 3740 kW. Keywords: Supercritical CO2cycle, Organic Rankine cycle, Exergetic performance, SPTCs, Organic fluids

  1. Improving Process Heating System Performance v3

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-04-11

    Improving Process Heating System Performance: A Sourcebook for Industry is a development of the U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) and the Industrial Heating Equipment Association (IHEA). The AMO and IHEA undertook this project as part of an series of sourcebook publications developed by AMO on energy-consuming industrial systems, and opportunities to improve performance. Other topics in this series include compressed air systems, pumping systems, fan systems, steam systems, and motors and drives

  2. Performance improvement plan in customer technical services

    International Nuclear Information System (INIS)

    Lachambre, L.

    1995-01-01

    This presentation centred around the philosophy, goals, and initiatives associated with Gaz Metropolitain's performance improvement plan. Various aspects of the plan including customer surveys, new customer service policies, the creation of small working units, the decentralization of the Montreal service department, and customer-harmonized shift schedules were explored. Implementation of new service plans and contracts, the formation of improvement groups related to human resources, human resource and productivity management, leadership training, and the use of performance indicators were also explained

  3. An Adaptive Middleware for Improved Computational Performance

    DEFF Research Database (Denmark)

    Bonnichsen, Lars Frydendal

    , we are improving computational performance by exploiting modern hardware features, such as dynamic voltage-frequency scaling and transactional memory. Adapting software is an iterative process, requiring that we continually revisit it to meet new requirements or realities; a time consuming process......The performance improvements in computer systems over the past 60 years have been fueled by an exponential increase in energy efficiency. In recent years, the phenomenon known as the end of Dennard’s scaling has slowed energy efficiency improvements — but improving computer energy efficiency...... is more important now than ever. Traditionally, most improvements in computer energy efficiency have come from improvements in lithography — the ability to produce smaller transistors — and computer architecture - the ability to apply those transistors efficiently. Since the end of scaling, we have seen...

  4. Combined cycle power plants: technological prospects for improving the efficiency

    International Nuclear Information System (INIS)

    Lauri, R.

    2009-01-01

    The combined cycle power plants characteristics are better than one course open to a closed loop presenting an electrical efficiency close to 60% do not reach for gas turbine engines for power plants and conventional steam engines. [it

  5. Uranium resource utilization improvements in the once-through PWR fuel cycle

    International Nuclear Information System (INIS)

    Matzie, R.A.

    1980-04-01

    In support of the Nonproliferation Alternative Systems Assessment Program (NASAP), Combustion Engineering, Inc. performed a comprehensive analytical study of potential uranium utilization improvement options that can be backfit into existing PWRs operating on the once-through uranium fuel cycle. A large number of potential improvement options were examined as part of a preliminary survey of candidate options. The most attractive of these, from the standpoint of uranium utilization improvement, economic viability, and ease of implementation, were then selected for detailed analysis and were included in a single composite improvement case. This composite case represents an estimate of the total savings in U 3 O 8 consumption that can be achieved in current-design PWRs by implementing improvements which can be developed and demonstrated in the near term. The improvement options which were evaluated in detail and included in the composite case were a new five-batch, extended-burnup fuel management scheme, low-leakage fuel management, modified lattice designs, axial blankets, reinsertion of initial core batches, and end-of-cycle stretchout

  6. Nuclear Systems Enhanced Performance Program, Maintenance Cycle Extension in Advanced Light Water Reactor Design

    Energy Technology Data Exchange (ETDEWEB)

    Professor Neill Todreas

    2001-10-01

    A renewed interest in new nuclear power generation in the US has spurred interest in developing advanced reactors with features which will address the public's concerns regarding nuclear generation. However, it is economic performance which will dictate whether any new orders for these plants will materialize. Economic performance is, to a great extent, improved by maximizing the time that the plant is on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Indeed, the strategy for the advanced light water reactor plant IRIS (International Reactor, Innovative and Secure) is to utilize an eight year operating cycle. This report describes a formalized strategy to address, during the design phase, the maintenance-related barriers to an extended operating cycle. The top-level objective of this investigation was to develop a methodology for injecting component and system maintainability issues into the reactor plant design process to overcome these barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the IRIS design. The first step in meeting the top-level objective was to determine the types of operating cycle length barriers that the IRIS design team is likely to face. Evaluation of previously identified regulatory and investment protection surveillance program barriers preventing a candidate operating PWR from achieving an extended (48 month) cycle was conducted in the context of the IRIS design. From this analysis, 54 known IRIS operating cycle length barriers were identified. The resolution methodology was applied to each of these barriers to generate design solution alternatives for consideration in the IRIS design. The methodology developed has been demonstrated to narrow the design space to feasible design solutions which enable a desired operating cycle length, yet is general enough to have broad applicability. Feedback from the IRIS design team

  7. EFFECT OF THE ROTOR CRANK SYSTEM ON CYCLING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Simon A. Jobson

    2009-09-01

    Full Text Available The aim of this study was to evaluate the impact of a novel crank system on laboratory time-trial cycling performance. The Rotor system makes each pedal independent from the other so that the cranks are no longer fixed at 180°. Twelve male competitive but non-elite cyclists (mean ± s: 35 ± 7 yr, Wmax = 363 ± 38 W, VO2peak = 4.5 ± 0.3 L·min-1 completed 6-weeks of their normal training using either a conventional (CON or the novel Rotor (ROT pedal system. All participants then completed two 40.23-km time-trials on an air-braked ergometer, one using CON and one using ROT. Mean performance speeds were not different between trials (CON = 41.7 km·h-1 vs. ROT = 41.6 km·h-1, P > 0.05. Indeed, the pedal system used during the time-trials had no impact on any of the measured variables (power output, cadence, heart rate, VO2, RER, gross efficiency. Furthermore, the ANOVA identified no significant interaction effect between main effects (Time-trial crank system*Training crank system, P > 0.05. To the authors' knowledge, this is the first study to examine the effects of the Rotor system on endurance performance rather than endurance capacity. These results suggest that the Rotor system has no measurable impact on time-trial performance. However, further studies should examine the importance of the Rotor 'regulation point' and the suggestion that the Rotor system has acute ergogenic effects if used infrequently

  8. Peer Mentors Can Improve Academic Performance

    Science.gov (United States)

    Asgari, Shaki; Carter, Frederick, Jr.

    2016-01-01

    The present study examined the relationship between peer mentoring and academic performance. Students from two introductory psychology classes either received (n = 37) or did not receive (n = 36) peer mentoring. The data indicated a consistent improvement in the performance (i.e., grades on scheduled exams) of the mentored group. A similar pattern…

  9. Do Leadership Changes Improve Electoral Performance?

    NARCIS (Netherlands)

    Helboe Pedersen, H.; Schumacher, G.; Cross, W.; Pilet, J.-B.

    2015-01-01

    Does changing the leader improve a party’s electoral performance? And does it matter who for electoral performance who selects the leader? We hypothesize that in parties with inclusive selectorates leadership change is beneficial because the competition for the leadership is more open, receives more

  10. World class performance: the outage/operating cycle continuum

    Energy Technology Data Exchange (ETDEWEB)

    Remphal, M. [Ontario Power Generation, Darlington, Ontario (Canada)

    2011-07-01

    It's all about Performance! Predictable and sustainable high performance is the key to public and stakeholder confidence in the nuclear industry. Why? Because nuclear is unique and safe, reliable operation each and every day is required to keep public trust. What better way to demonstrate this predictability than in breaker to breaker operating runs? Delivering on what was promised is the essence of our OPG accountability model: 'Say it, Do it'. This presentation is drawn from practical experience gained during the most recent planned maintenance outages at Darlington Nuclear. Key elements for outage success that will be discussed include; Human Performance: Ensuring each action is deliberate and executed right the first time; Continuous Learning: Recent examples demonstrating how drawing from lessons learned and operating experience worldwide can dramatically improve outage performance; Teamwork and Partnership: Recognizing our industry is too complex for a single; individual or organization to run on its own; Scope Selection: Darlington currently has an industry leading 0.5% Forced Loss Rate (FLR). If right work is selected and executed at the right time then ultimately the plant speaks and it shows up in low FLR and high Nuclear Performance Index; Planning: Ask and anticipate what can go wrong, what options exist and then pre-decide what path you would take. Some practical tools will be provided which have been recently used to plan out surprises; Oversight: An outage left to run its own course will have a surprise outcome. Strong management oversight is required to meet the goals of outage execution. Tips on how to improve communication and accountability will be discussed. Trust is built on confidence and confidence is built on sustainable performance. World class sustainable performance requires using all the tools available. This discussion will provide insight on these very tools. (author)

  11. World class performance: the outage/operating cycle continuum

    International Nuclear Information System (INIS)

    Remphal, M.

    2011-01-01

    It's all about Performance! Predictable and sustainable high performance is the key to public and stakeholder confidence in the nuclear industry. Why? Because nuclear is unique and safe, reliable operation each and every day is required to keep public trust. What better way to demonstrate this predictability than in breaker to breaker operating runs? Delivering on what was promised is the essence of our OPG accountability model: 'Say it, Do it'. This presentation is drawn from practical experience gained during the most recent planned maintenance outages at Darlington Nuclear. Key elements for outage success that will be discussed include; Human Performance: Ensuring each action is deliberate and executed right the first time; Continuous Learning: Recent examples demonstrating how drawing from lessons learned and operating experience worldwide can dramatically improve outage performance; Teamwork and Partnership: Recognizing our industry is too complex for a single; individual or organization to run on its own; Scope Selection: Darlington currently has an industry leading 0.5% Forced Loss Rate (FLR). If right work is selected and executed at the right time then ultimately the plant speaks and it shows up in low FLR and high Nuclear Performance Index; Planning: Ask and anticipate what can go wrong, what options exist and then pre-decide what path you would take. Some practical tools will be provided which have been recently used to plan out surprises; Oversight: An outage left to run its own course will have a surprise outcome. Strong management oversight is required to meet the goals of outage execution. Tips on how to improve communication and accountability will be discussed. Trust is built on confidence and confidence is built on sustainable performance. World class sustainable performance requires using all the tools available. This discussion will provide insight on these very tools. (author)

  12. South Bank Coke Ovens heating performance improvements

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, A.J. [South Bank Coke Ovens (United Kingdom)

    1995-12-31

    The coke oven batteries at South Bank Coke Ovens had a history of refractory failure, overheating, and poor environmental performance despite repeated attempts to solve the problem. The fundamental design was poor, but previous upgrade attempts had a history of short term improvements followed by renewed decline, suggesting that the problem may not merely with the equipment. An audit of the area showed multiple morale, equipment and communications problems, although a significant proportion of the workforce were interested in improving the situation. A group of those interested in performance improvements was called together and objectives agreed upon. Communications were upgraded and problem walls analysed for their particular weaknesses. A team approach was used for maintenance, leading to slowly improving pushing emission factors. Temperature control equipment ensured better environmental performance and lower electricity consumption. 5 refs., 3 figs.

  13. Improving human performance: Industry factors influencing the ability to perform

    OpenAIRE

    Güera Massyn Romo

    2013-01-01

    Learning interventions and new technologies that aim to improve human performance must take cognisance of industry factors inhibiting human performance. The dynamic and fast pace nature of the Information and Communication Technologies (ICT) and the engineering industries do not lend themselves to proper skills planning and management. These industries experience real skills gaps, to some of which they contribute by themselves. This study reports on these performance-inhibiting factors such a...

  14. Performance improvement integration: a whole systems approach.

    Science.gov (United States)

    Page, C K

    1999-02-01

    Performance improvement integration in health care organizations is a challenge for health care leaders. Required for accreditation by the Joint Commission on Accreditation of Healthcare Organizations (Joint Commission), performance improvement (PI) can be designed as a sustainable model for performance to survive in a turbulent period. Central Baptist Hospital developed a model for PI that focused on strategy established by the leadership team, delineated responsibility through the organizational structure of shared governance, and accountability for outcomes evidenced through the organization's profitability. Such an approach integrated into the culture of the organization can produce positive financial margins, positive customer satisfaction, and commendations from the Joint Commission.

  15. Do school inspections improve primary school performance?

    OpenAIRE

    Dinand Webbink; Rob Luginbuhl; I. de Wolf

    2007-01-01

    Inspectors from the Dutch Inspectorate of Education inspect primary schools, write inspection reports on each inspected school, and make recommendations as to how each school can improve. We test whether these inspections result in better school performance. Using a fixed-effects model, we find evidence that school inspections do lead to measurably better school performance. Our assessment of school performance is based on the Cito test scores of pupils in their final year of primary school. ...

  16. Monitoring Perceived Stress and Recovery in Relation to Cycling Performance in Female Athletes.

    Science.gov (United States)

    Otter, R T A; Brink, M S; van der Does, H T D; Lemmink, K A P M

    2016-01-01

    The purpose was to investigate perceived stress and recovery related to cycling performance of female athletes over one full year. 20 female athletes (age, 27±8 years; ˙VO2max, 50.3±4.6 mL·kg(-1)·min(-1)) were measured 8 times in one year to determine perceived stress and recovery (RESTQ-Sport) in relation to cycling performance (Lamberts and Lambert Submaximal Cycle Test (LSCT)). All 19 RESTQ-Sport scales were calculated and scores of the 4 main categories were determined (i. e., general stress, general recovery, sport-specific stress and sport-specific recovery). A balance score of total stress and recovery was calculated by recovery-stress. Power at the second stage (P80), third stage (P90) and heart rate recovery (HRR60 s) of the LSCT were determined as performance parameters. 110 RESTQ-Sports and LSCTs were analysed using a multilevel approach (random intercepts model). Higher self-efficacy was related to improvement of all performance parameters. Higher total recovery stress, and lower emotional stress were related to improvement of P90 and HRR60 s. Higher sport-specific recovery was related to P80, higher general stress, fatigue and physical complaints were related to decreased P90 and higher social stress and injury were related to decreased HRR60 s. Improved perceived recovery and stress contributed to an improved performance. Relevant information could be provided by monitoring changes in perceived stress and recovery of female athletes. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Standalone BISON Fuel Performance Results for Watts Bar Unit 1, Cycles 1-3

    Energy Technology Data Exchange (ETDEWEB)

    Clarno, Kevin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pawlowski, Roger [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stimpson, Shane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Jeffrey [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-03-07

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is moving forward with more complex multiphysics simulations and increased focus on incorporating fuel performance analysis methods. The coupled neutronics/thermal-hydraulics capabilities within the Virtual Environment for Reactor Applications Core Simulator (VERA-CS) have become relatively stable, and major advances have been made in analysis efforts, including the simulation of twelve cycles of Watts Bar Nuclear Unit 1 (WBN1) operation. While this is a major achievement, the VERA-CS approaches for treating fuel pin heat transfer have well-known limitations that could be eliminated through better integration with the BISON fuel performance code. Several approaches are being implemented to consider fuel performance, including a more direct multiway coupling with Tiamat, as well as a more loosely coupled one-way approach with standalone BISON cases. Fuel performance typically undergoes an independent analysis using a standalone fuel performance code with manually specified input defined from an independent core simulator solution or set of assumptions. This report summarizes the improvements made since the initial milestone to execute BISON from VERA-CS output. Many of these improvements were prompted through tighter collaboration with the BISON development team at Idaho National Laboratory (INL). A brief description of WBN1 and some of the VERA-CS data used to simulate it are presented. Data from a small mesh sensitivity study are shown, which helps justify the mesh parameters used in this work. The multi-cycle results are presented, followed by the results for the first three cycles of WBN1 operation, particularly the parameters of interest to pellet-clad interaction (PCI) screening (fuel-clad gap closure, maximum centerline fuel temperature, maximum/minimum clad hoop stress, and cumulative damage index). Once the mechanics of this capability are functioning, future work will target cycles with

  18. Improving Mobility Performance in Wheelchair Basketball.

    Science.gov (United States)

    Veeger, Thom T J; De Witte, Annemarie M H; Berger, Monique A M; Van Der Slikke, Rienk M A; Veeger, Dirkjan H E J; Hoozemans, Marco J M

    2017-10-16

    This study aimed to investigate which characteristics of athlete, wheelchair and athlete-wheelchair interface are the best predictors of wheelchair basketball mobility performance. Sixty experienced wheelchair basketball players performed a wheelchair mobility performance test to assess their mobility performance. To determine which variables were the best predictors of mobility performance, forward stepwise linear regression analyses were performed on a set of 33 characteristics, including ten athlete, nineteen wheelchair and four athlete-wheelchair interface characteristics. Eight of the characteristics turned out to be significant predictors of wheelchair basketball mobility performance. Classification, experience, maximal isometric force, wheel axis height and hand rim diameter - which both interchangeable with each other and wheel diameter - camber angle, and the vertical distance between shoulder and rear wheel axis - which was interchangeable with seat height - were positively associated with mobility performance. The vertical distance between the front seat and the footrest was negatively associated with mobility performance. With this insight, coaches and biomechanical specialists are provided with statistical findings to determine which characteristics they could focus on best to improve mobility performance. Six out of eight predictors are modifiable and can be optimized to improve mobility performance. These adjustments could be carried out both in training (maximal isometric force) and in wheelchair configurations (e.g. camber angle).

  19. PDCA cycle as a part of continuous improvement in the production company - a case study

    Directory of Open Access Journals (Sweden)

    Marta Jagusiak-Kocik

    2017-04-01

    Full Text Available The paper presents a case study of the practical use of Deming cycle in a manufacturing company, from the plastics processing industry, from the sector of small and medium-sized enterprises. The paper is a study of literature in the field of continuous improvement and characterized by a cycle of continuous improvement, called the Deming cycle, or PDCA cycle. This cycle was used as a solution to quality problems which occurred during production of photo frames: discolorations and scorches on the surface of the frame. When measures were introduced to reduce the number of nonconformities, a decrease by more than 60% was observed.

  20. An analysis of fuel performance cycle 20 of BWR unit 2

    International Nuclear Information System (INIS)

    Hemantha Rao, G.V.S.; Prasad, P.N.; Jayaraj, R.N.

    2008-01-01

    Nuclear Fuel Complex (NFC), an industrial unit of the Department of Atomic Energy (DAE), Government of India manufactures and supplies fuel assemblies to the two Boiling Water Reactors (BWR) at Tarapur Atomic Power Station (TAPS 1 and 2) in India which were commissioned on turnkey collaboration with GE, USA. Each fuel assembly has 36 fuel elements arranged in 6x6 square configuration. Each fuel assembly contains UO 2 pellets of different enrichments. Several improvements have been carried out over the years in the manufacture of fuel assemblies. These changes have helped in improving the fuel performance considerably. During cycle 20, the unit 2 was operating at 506/153 MWth/MWe (95.47% of rated thermal power of 530MWth) prior to shut down for refueling outage. In core sipping was completed within two days. Five leakers were identified during in core sipping. The average leaky assembly's exposure was 16,098.4 MWD/T. The minimum value of a leaky assembly's exposure was 8,591 MWD/T. Out of five assemblies, four assemblies had seen two cycles of exposure and were due for discharge. One assembly had seen single cycle. Trend of chemistry parameters for the last four cycles were within tech spec limits. Similarly trend of physics parameters for the fuel assemblies for the last cycles were also within design/tech spec limits. There were no fuel failures in the previous cycles 18 and 19. The manufacturing and QA details of the five assemblies show no deviations from the procedures and the trends are normal and within specified limits. This paper discusses the analysis of fuel failures in detail

  1. Improving early cycle economic evaluation of diagnostic technologies

    NARCIS (Netherlands)

    Steuten, Lotte Maria Gertruda; Ramsey, Scott D.

    2014-01-01

    The rapidly increasing range and expense of new diagnostics, compels consideration of a different, more proactive approach to health economic evaluation of diagnostic technologies. Early cycle economic evaluation is a decision analytic approach to evaluate technologies in development so as to

  2. Perform Thermodynamics Measurements on Fuel Cycle Case Study Systems

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Leigh R. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This document was prepared to meet FCR&D level 3 milestone M3FT-14IN0304022, “Perform Thermodynamics Measurements on Fuel Cycle Case Study Systems.” This work was carried out under the auspices of the Thermodynamics and Kinetics FCR&D work package. This document reports preliminary work in support of determining the thermodynamic parameters for the ALSEP process. The ALSEP process is a mixed extractant system comprised of a cation exchanger 2-ethylhexyl-phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and a neutral solvating extractant N,N,N’,N’-tetraoctyldiglycolamide (TODGA). The extractant combination produces complex organic phase chemistry that is challenging for traditional measurement techniques. To neutralize the complexity, temperature dependent solvent extraction experiments were conducted with neat TODGA and scaled down concentrations of the ALSEP formulation to determine the enthalpies of extraction for the two conditions. A full set of thermodynamic data for Eu, Am, and Cm extraction by TODGA from 3.0 M HNO3 is reported. These data are compared to previous extraction results from a 1.0 M HNO3 aqueous medium, and a short discussion of the mixed HEH[EHP]/TODGA system results is offered.

  3. Dynamic high-cadence cycling improves motor symptoms in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Angela eRidgel

    2015-09-01

    Full Text Available Rationale: Individuals with Parkinson’s disease (PD often have deficits in kinesthesia. There is a need for rehabilitation interventions that improve these kinesthetic deficits. Forced (tandem cycling at a high cadence improves motor function. However, tandem cycling is difficult to implement in a rehabilitation setting. Objective: To construct an instrumented, motored cycle and to examine if high cadence dynamic cycling promotes improvements in motor function. Method: This motored cycle had two different modes: dynamic and static cycling. In dynamic mode, the motor maintained 75-85 rpm. In static mode, the rider determined the pedaling cadence. UPDRS Motor III and Timed Up and Go (TUG were used to assess changes in motor function after three cycling sessions. Results: Individuals in the static group showed a lower cadence but a higher power, torque and heart rate than the dynamic group. UPDRS score showed a significant 13.9% improvement in the dynamic group and only a 0.9% improvement in the static group. There was also a 16.5% improvement in TUG time in the dynamic group but only an 8% improvement in the static group. Conclusion: These findings show that dynamic cycling can improve PD motor function and that activation of proprioceptors with a high cadence but variable pattern may be important for motor improvements in PD.

  4. [Primary care for diabetic patients: a quality improvement cycle].

    Science.gov (United States)

    Navarro-Martínez, A; Suárez-Beke, M P; Sánchez-Nicolás, J A; Lázaro-Aragues, P; de Jesús Jiménez-Vázquez, E; Huertas-de Mora, O

    2014-01-01

    The aim of this study was to evaluate and improve the quality of medical care provided to diabetic patients following the standards proposed by the American Diabetes Association. The study was conducted in three phases by analyzing data from the computerized clinical history of a sample of 340 patients. First phase (2010): cross-sectional, descriptive study which assessed the proportion of patients who met the standards related to the screening of diabetes, and goals of control and treatment. Subsequently, health professionals reviewed the results in order to promote the implementation of corrective action. Finally (2012), a new assessment with the same standards was performed. An increase in the number of patients treated with insulin (12.7% in 2010 and 20.2% in 2012) was observed (P < .01). There were also percentage increases in the number of patients who met the screening standards as regards analytical determinations: glycosylated hemoglobin (from 44.4% to 68.2%), lipid profile (47.6%-73.8%), creatinine (32.5% - 73.5%), and albumin-creatinine ratio (9.2%-24.4%) (P < .001). Only 6.4% (CI: 3.2- 9.8) of diabetic patients attained the composite target of glycosylated hemoglobin < 7%, blood pressure < 130/80 mmHg and low-density lipoprotein cholesterol < 100 mg/dl in 2012. This study shows that medical care has improved the goals related to analytical determinations and the number of insulin-treated diabetic type 2 patients. An optimal level was also maintained in metabolic control of diabetes, but there was still poor control of risk factors for cardiovascular disease. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.

  5. Business cycles and the financial performance of fuel cell companies

    International Nuclear Information System (INIS)

    Henriques, I.; Sadorsky, P.

    2005-01-01

    Fuel cells are expected to play a major role in a hydrogen powered world. They will provide power to homes, modes of transportation and appliances. Hydrogen is the most abundant element in nature, but it must be extracted in order to be usable. It can be produced from oil, natural gas and coal or from renewable sources such as biomass, thermal or nuclear reactions. Fuel cells running on hydrogen extracted from non renewable resources have an efficiency of 30 per cent, which is twice as efficient as an internal combustion engine. The greatest barrier to mass commercialization is the cost of making hydrogen-powered auto engines. Also, an infrastructure must be developed to refill hydrogen cars. One solution is to build a hydrogen highway using the existing natural gas grid to produce hydrogen and sell it at existing filling stations. The cost of building 12,000 refueling pumps in urban areas which will provide access to 70 per cent of America's population is estimated at $10 to $15 billion. This paper described the vector autoregression (VAR) model which empirically examines the relationship between financial performance of fuel cell companies and business cycles. It was used to measure how sensitive the financial performance of fuel cell companies are to changes in macroeconomic activity. A four variable VAR model was developed to examine the relationship between stock prices, oil prices and interest rates. It was shown that the stock prices of fuel cell companies are affected by shocks to technology stock prices and oil prices, with the former having a longer lasting impact. These results add to the growing literature that oil price movements are not as important as once thought. 15 refs., 3 tabs., 3 figs

  6. Goals and experience of performance improvement

    Energy Technology Data Exchange (ETDEWEB)

    Tan, H. [CNNO, CNNP, Nuclear Power Operations Management Co., Ltd. (China)

    2015-07-01

    Performance improvement was achieved by reasonable arrangement of planned window for related work and optimization of time for important maintenance items, outage quality and duration. Unplanned output loss has been reduced through routine unit management and improvements to both personnel skill and equipment reliability. Planned power generation loss is reduced by controlling planned duration and quality of forced shutdowns and outages, to ensure safe and stable plant operation.

  7. Performance improvement using methodology: case study.

    Science.gov (United States)

    Harmelink, Stacy

    2008-01-01

    The department of radiology at St. Luke's Regional Medical Center in Sioux City, IA implemented meaningful workflow changes for reducing patient wait times and, at the same time, improved customer and employee satisfaction scores. Lean methodology and the 7 Deadly Wastes, along with small group interaction, was used to evaluate and change the process of a patient waiting for an exam in the radiology department. The most important key to the success of a performance improvement project is the involvement of staff.

  8. Improving human performance in maintenance personnel

    International Nuclear Information System (INIS)

    Gonzalez Anez, Francisco; Agueero Agueero, Jorge

    2010-01-01

    The continuous evolution and improvement of safety-related processes has included the analysis, design and development of training plans for the qualification of maintenance nuclear power plant personnel. In this respect, the international references in this area recommend the establishment of systematic qualification programmes for personnel performing functions or carrying out safety related tasks. Maintenance personnel qualification processes have improved significantly, and training plans have been designed and developed based on Systematic Approach to Training methodology to each job position. These improvements have been clearly reflected in recent training programmes with new training material and training facilities focused not only on developing technical knowledge and skills but also on improving attitudes and safety culture. The objectives of maintenance training facilities such as laboratories, mock-ups real an virtual, hydraulic loops, field simulators and other training material to be used in the maintenance training centre are to cover training necessities for initial and continuous qualification. Evidently, all these improvements made in the qualification of plant personnel should be extended to include supplemental personnel (external or contracted) performing safety-related tasks. The supplemental personnel constitute a very spread group, covering the performance of multiple activities entailing different levels of responsibility. Some of these activities are performed permanently at the plant, while others are occasional or sporadic. In order to establish qualification requirements for these supplemental workers, it is recommended to establish a rigorous analysis of job positions and tasks. The objective will be to identify the qualification requirements to assure competence and safety. (authors)

  9. How to assess performance in cycling: the multivariate nature of influencing factors and related indicators

    Science.gov (United States)

    Castronovo, A. Margherita; Conforto, Silvia; Schmid, Maurizio; Bibbo, Daniele; D'Alessio, Tommaso

    2013-01-01

    Finding an optimum for the cycling performance is not a trivial matter, since the literature shows the presence of many controversial aspects. In order to quantify different levels of performance, several indexes have been defined and used in many studies, reflecting variations in physiological and biomechanical factors. In particular, indexes such as Gross Efficiency (GE), Net Efficiency (NE) and Delta Efficiency (DE) have been referred to changes in metabolic efficiency (EffMet), while the Indexes of Effectiveness (IE), defined over the complete crank revolution or over part of it, have been referred to variations in mechanical effectiveness (EffMech). All these indicators quantify the variations of different factors [i.e., muscle fibers type distribution, pedaling cadence, setup of the bicycle frame, muscular fatigue (MFat), environmental variables, ergogenic aids, psychological traits (PsychTr)], which, moreover, show high mutual correlation. In the attempt of assessing cycling performance, most studies in the literature keep all these factors separated. This may bring to misleading results, leaving unanswered the question of how to improve cycling performance. This work provides an overview on the studies involving indexes and factors usually related to performance monitoring and assessment in cycling. In particular, in order to clarify all those aspects, the mutual interactions among these factors are highlighted, in view of a global performance assessment. Moreover, a proposal is presented advocating for a model-based approach that considers all factors mentioned in the survey, including the mutual interaction effects, for the definition of an objective function E representing the overall effectiveness of a training program in terms of both EffMet and EffMech. PMID:23734130

  10. How to Assess Performance in Cycling: the Multivariate Nature of Influencing Factors and Related Indicators.

    Directory of Open Access Journals (Sweden)

    Anna Margherita eCastronovo

    2013-05-01

    Full Text Available Finding an optimum for the cycling performance is not a trivial matter, since the literature shows the presence of many controversial aspects. In order to quantify different levels of performance, several indexes have been defined and used in many studies, reflecting variations in physiological and biomechanical factors. In particular, indexes such as Gross Efficiency (GE, Net Efficiency (NE and Delta Efficiency (DE have been referred to changes in metabolic efficiency (EffMet, while the Indexes of Effectiveness (IE, defined over the complete crank revolution or over part of it, have been referred to variations in mechanical effectiveness (EffMech. All these indicators quantify the variations of different factors (i.e. muscle fibers type distribution, pedaling cadence, setup of the bicycle frame, muscular fatigue, environmental variables, ergogenic aids, psychological traits, which, moreover, show high mutual correlation. In the attempt of assessing cycling performance, most studies in the literature keep all these factors separated. This may bring to misleading results, leaving unanswered the question of how to improve cycling performance. This work provides an overview on the studies involving indexes and factors usually related to performance monitoring and assessment in cycling. In particular, in order to clarify all those aspects, the mutual interactions among these factors are highlighted, in view of a global performance assessment. Moreover, a proposal is presented advocating for a model-based approach that considers all factors mentioned in the survey, including the mutual interaction effects, for the definition of an objective function E representing the overall effectiveness of a training program in terms of both metabolic efficiency and mechanical effectiveness.

  11. Recent technology on steam turbine performance improvement

    International Nuclear Information System (INIS)

    Hirada, M.; Watanabe, E.; Tashiro, H.

    1991-01-01

    Continuous efforts have been made to improve turbine efficiency by applying the latest aerodynamic technologies to meet the energy saving requirement. In recent years, there has been considerable improvement in the field of computational fluid dynamics and these new technologies have been applied to the new blade design for HP, IP and LP turbines. Experimental verification for the new blade in turbine tests has established the overall turbine performance improvement and the excellent correspondence of flow pattern to the predicted value. This paper introduces the latest design technologies for the newly developed high efficiency blade and the verification test results

  12. Design aspects of PHWR for improved performance

    International Nuclear Information System (INIS)

    Das, M.

    1989-01-01

    The PHWR fuel bundle is elegantly simple in design consisting of only six components. The unique features of the design include high density natural UO 2 pellets, collapsible zircaloy cladding, no gas plenums and short (50 cm), simple bundle configuration. Over the last 20 years, considerable efforts have been expended and still being continued on development of analytical tools and computer codes generation of technical specifications tests and experimental studies type tests on prototype bundles irradiation of special documented fuel bundles in power reactors and monitoring and analysis of fuel performance. The knowledge thus gained has helped us to modify design requirements, relax technical specifications and to evolve new, improved designs. The PHWR fuel technology in India can now be considered as well proven but there is considerable scope for further improvements both in design and manufacturing. For example, in design, use of thinner wall cladding (to improve burn up) bundle design with graded elements, double dished pellet, improved coatings, use of MOX fuel etc. are being explored. On the manufacturing side emphasis need to be given on maintaining the quality, improvement on production and process control. The use of automation and advances in machine control techniques, for example, using micro processors can effectively contribute to improvements in quality, productivity and lowering of fuel fabrication costs. In this paper, the PHWR fuel design features, different fuel designs evolved, fuel specifications, influence of fabrication variables and future direction in improved fuel performance are discussed. (author) 9 refs., 7 figs

  13. Improving patient handover between teams using a business improvement model: PDSA cycle.

    Science.gov (United States)

    Luther, Vishal; Hammersley, Daniel; Chekairi, Ahmed

    2014-01-01

    Medical admission units are continuously under pressure to move patients off the unit to outlying medical wards and allow for new admissions. In a typical district general hospital, doctors working in these medical wards reported that, on average, three patients each week arrived from the medical admission unit before any handover was received, and a further two patients arrived without any handover at all. A quality improvement project was therefore conducted using a 'Plan, Do, Study, Act' cycle model for improvement to address this issue. P - Plan: as there was no framework to support doctors with handover, a series of standard handover procedures were designed. D - Do: the procedures were disseminated to all staff, and championed by key stakeholders, including the clinical director and matron of the medical admission unit. S - STUDY: Measurements were repeated 3 months later and showed no change in the primary end points. A - ACT: The post take ward round sheet was redesigned, creating a checkbox for a medical admission unit doctor to document that handover had occurred. Nursing staff were prohibited from moving the patient off the ward until this had been completed. This later evolved into a separate handover sheet. Six months later, a repeat study revealed that only one patient each week was arriving before or without a verbal handover. Using a 'Plan, Do, Study, Act' business improvement tool helped to improve patient care.

  14. Improved Function and Reduced Pain after Swimming and Cycling Training in Patients with Osteoarthritis.

    Science.gov (United States)

    Alkatan, Mohammed; Baker, Jeffrey R; Machin, Daniel R; Park, Wonil; Akkari, Amanda S; Pasha, Evan P; Tanaka, Hirofumi

    2016-03-01

    Arthritis and its associated joint pain act as significant barriers for adults attempting to perform land-based physical activity. Swimming can be an ideal form of exercise for patients with arthritis. Yet there is no information on the efficacy of regular swimming exercise involving patients with arthritis. The effect of a swimming exercise intervention on joint pain, stiffness, and physical function was evaluated in patients with osteoarthritis (OA). Using a randomized study design, 48 sedentary middle-aged and older adults with OA underwent 3 months of either swimming or cycling exercise training. Supervised exercise training was performed for 45 min/day, 3 days/week at 60-70% heart rate reserve for 12 weeks. The Western Ontario and McMaster Universities Arthritis Index was used to measure joint pain, stiffness, and physical limitation. After the exercise interventions, there were significant reductions in joint pain, stiffness, and physical limitation accompanied by increases in quality of life in both groups (all p swimming and cycling training. Regular swimming exercise reduced joint pain and stiffness associated with OA and improved muscle strength and functional capacity in middle-aged and older adults with OA. Additionally, the benefits of swimming exercise were similar to the more frequently prescribed land-based cycling training. clinicaltrials.gov NCT01836380.

  15. Purchasing to improve health systems performance

    National Research Council Canada - National Science Library

    Robinson, Ray; Jakubowski, Elke; Figueras, Josep

    2005-01-01

    ... as they formulate purchasing strategies so that they can increase effectiveness and improve performance in their own national context An assessment of the intersecting roles of citizens, the government and the providers * * * Written by leading health policy analysts, this book is essential reading for health policy makers, planners and managers as well as resear...

  16. Improving the Performance of Justice Institutions

    OpenAIRE

    Decker, Klaus; Mohlen, Christian; Varela, David F.

    2011-01-01

    This paper presents a selection of experiences from Organization for Economic Cooperation and Development (OECD) countries in managing justice institutions which are the most relevant for performance improvement of their counterparts in Latin America. The scope of the paper is mostly limited to the courts, but comprises all types of courts: specialized courts as well as courts of general j...

  17. The People Side of Performance Improvement.

    Science.gov (United States)

    Gerson, Richard F.

    1999-01-01

    Discusses 11 keys to the personal side of performance improvement, including positive attitude, high self esteem and positive self-image, communication skills, lifelong learning, caring about other people, health and well-being, motivation, goal setting, relaxation, visualization, and personal value system. (LRW)

  18. Performances of Saft Lithium-Ion Cells in LEO Cycling

    Directory of Open Access Journals (Sweden)

    Prevot D.

    2017-01-01

    The article will thus present the whole LEO cycling results available for the two cells, and will provide afterwards the correlation status of Saft Li-ion Model (SLIM with all the experimental data acquired.

  19. Citrus Flavonoid Supplementation Improves Exercise Performance in Trained Athletes

    Directory of Open Access Journals (Sweden)

    Elvera Overdevest, Jeroen A. Wouters, Kevin H.M. Wolfs, Job J.M. van Leeuwen, Sam Possemiers

    2018-03-01

    Full Text Available Previous studies have shown that polyphenol supplementation may be an effective strategy to improve exercise performance, due to their antioxidant character and ability to stimulate NO production. These properties may contribute to exercise performance, yet no conclusive research has been performed in exploring the direct effects of citrus flavonoids on human exercise performance. Therefore, the purpose of this study was to assess whether supplementation of a customized citrus flavonoid (CF extract for 4 weeks improves cycling time-trial performance in trained male athletes. In a double-blind, randomized, parallel study, 39 healthy, trained males were given a daily dose of either 500 mg of a customized citrus flavonoid extract (CF or a placebo for 4 weeks. Exercise performance was tested by means of a time-trial test on a cycle ergometer, during which participants had to generate as much power as possible for duration of 10 minutes. Absolute power output significantly increased with 14.9 ± 3.9 W after 4 weeks of CF supplementation, corresponding with a 5.0% increase, compared to 3.8 ± 3.2 W (1.3% increase in placebo (p < 0.05. In addition, oxygen consumption/power ratio significantly decreased in the CF group compared to placebo (p = 0.001, and a trend was found in the change in peak power output in CF (18.2 ± 23.2 W versus placebo (-28.4 ± 17.6 W; p = 0.116. The current study is the first convincing report that citrus flavonoid supplementation can improve exercise performance, as shown by a significant increase in power output during the exercise test.

  20. Performance analysis of an Integrated Solar Combined Cycle using Direct Steam Generation in parabolic trough collectors

    International Nuclear Information System (INIS)

    Montes, M.J.; Rovira, A.; Munoz, M.; Martinez-Val, J.M.

    2011-01-01

    Highlights: → Solar hybridization improves the performance of CCGT in a very hot and dry weather. → The scheme analyzed is a DSG parabolic trough field coupled to the Rankine cycle. → An annual simulation has been carried out for two locations: Almeria and Las Vegas. → Economical analysis shows that this scheme is a cheaper way to exploit solar energy. → For that, solar hybridization must be limited to a small fraction of the CCGT power. - Abstract: The contribution of solar thermal power to improve the performance of gas-fired combined cycles in very hot and dry environmental conditions is analyzed in this work, in order to assess the potential of this technique, and to feature Direct Steam Generation (DSG) as a well suited candidate for achieving very good results in this quest. The particular Integrated Solar Combined Cycle (ISCC) power plant proposed consists of a DSG parabolic trough field coupled to the bottoming steam cycle of a Combined Cycle Gas Turbine (CCGT) power plant. For this analysis, the solar thermal power plant performs in a solar dispatching mode: the gas turbine always operates at full load, only depending on ambient conditions, whereas the steam turbine is somewhat boosted to accommodate the thermal hybridization from the solar field. Although the analysis is aimed to studying such complementary effects in the widest perspective, two relevant examples are given, corresponding to two well-known sites: Almeria (Spain), with a mediterranean climate, and Las Vegas (USA), with a hot and dry climate. The annual simulations show that, although the conventional CCGT power plant works worse in Las Vegas, owing to the higher temperatures, the ISCC system operates better in Las Vegas than in Almeria, because of solar hybridization is especially well coupled to the CCGT power plant in the frequent days with great solar radiation and high temperatures in Las Vegas. The complementary effect will be clearly seen in these cases, because the thermal

  1. High performance integrated solar combined cycles with minimum modifications to the combined cycle power plant design

    International Nuclear Information System (INIS)

    Manente, Giovanni

    2016-01-01

    Highlights: • Off-design model of a 390 MW_e three pressure combined cycle developed and validated. • The off-design model is used to evaluate different hybridization schemes with solar. • Power boosting and fuel saving with different design modifications are considered. • Maximum solar share of total electricity is only 1% with the existing equipment. • The maximum incremental solar radiation-to-electrical efficiency approaches 29%. - Abstract: The integration of solar energy into natural gas combined cycles has been successfully demonstrated in several integrated solar combined cycles since the beginning of this decade in many countries. There are many motivations that drive investments on integrated solar combined cycles which are primarily the repowering of existing power plants, the compliance with more severe environmental laws on emissions and the mitigation of risks associated with large solar projects. Integrated solar combined cycles are usually developed as brownfield facilities by retrofitting existing natural gas combined cycles and keeping the existing equipment to minimize costs. In this work a detailed off-design model of a 390 MW_e three pressure level natural gas combined cycle is built to evaluate different integration schemes of solar energy which either keep the equipment of the combined cycle unchanged or include new equipment (steam turbine, heat recovery steam generator). Both power boosting and fuel saving operation strategies are analyzed in the search for the highest annual efficiency and solar share. Results show that the maximum incremental power output from solar at design solar irradiance is limited to 19 MW_e without modifications to the existing equipment. Higher values are attainable only including a larger steam turbine. High solar radiation-to-electrical efficiencies in the range 24–29% can be achieved in the integrated solar combined cycle depending on solar share and extension of tube banks in the heat recovery

  2. Improving engineering performance by utilizing process indicators

    International Nuclear Information System (INIS)

    Roberts, T.E.

    1992-01-01

    The purpose of the work discussed in this paper was to develop engineering performance indicators used to facilitate improvement to the technical quality, cost-effectiveness, and delivery of engineering products and service. This work was specifically tailored for engineering support products and service associated with operating Florida Power and Light Company (FP and L) nuclear plants. The engineering process for the development of plant change packages was reviewed to identify critical in-process activities. Because each engineering project usually deals with a specific component or plant system, the different tasks are usually technically unique and of varying magnitudes. Although each engineering product may employ different analytical techniques or industry code requirements, several activities in documenting the engineering design process are generic. The quality of performance in these activities can be monitored analogously to the steps in a manufacturing process. This concept builds quality concepts into the package in lieu of inspecting package quality at the end of the process. The work has resulted in a valuable self-assessment tool that serves as a basis for engineering process improvements. The indicators are published in a semi-yearly performance report for FP and L contractors as well as FP and L in-house engineering work. Contracts have been set up to base fees on meeting targets established for the performance report. The ability to meet performance targets continues to improve

  3. Visuospatial training improves elementary students' mathematics performance.

    Science.gov (United States)

    Lowrie, Tom; Logan, Tracy; Ramful, Ajay

    2017-06-01

    Although spatial ability and mathematics performance are highly correlated, there is scant research on the extent to which spatial ability training can improve mathematics performance. This study evaluated the efficacy of a visuospatial intervention programme within classrooms to determine the effect on students' (1) spatial reasoning and (2) mathematics performance as a result of the intervention. The study involved grade six students (ages 10-12) in eight classes. There were five intervention classes (n = 120) and three non-intervention control classes (n = 66). A specifically designed 10-week spatial reasoning programme was developed collaboratively with the participating teachers, with the intervention replacing the standard mathematics curriculum. The five classroom teachers in the intervention programme presented 20 hr of activities aimed at enhancing students' spatial visualization, mental rotation, and spatial orientation skills. The spatial reasoning programme led to improvements in both spatial ability and mathematics performance relative to the control group who received standard mathematics instruction. Our study is the first to show that a classroom-based spatial reasoning intervention improves elementary school students' mathematics performance. © 2017 The British Psychological Society.

  4. Pre-task music improves swimming performance.

    Science.gov (United States)

    Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

    2015-12-01

    The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

  5. Performance analysis of a combined organic Rankine cycle and vapor compression cycle for power and refrigeration cogeneration

    International Nuclear Information System (INIS)

    Kim, Kyoung Hoon; Perez-Blanco, Horacio

    2015-01-01

    A thermodynamic analysis of cogeneration of power and refrigeration activated by low-grade sensible energy is presented in this work. An organic Rankine cycle (ORC) for power production and a vapor compression cycle (VCC) for refrigeration using the same working fluid are linked in the analysis, including the limiting case of cold production without net electricity production. We investigate the effects of key parameters on system performance such as net power production, refrigeration, and thermal and exergy efficiencies. Characteristic indexes proportional to the cost of heat exchangers or of turbines, such as total number of transfer units (NTU tot ), size parameter (SP) and isentropic volumetric flow ratio (VFR) are also examined. Three important system parameters are selected, namely turbine inlet temperature, turbine inlet pressure, and the flow division ratio. The analysis is conducted for several different working fluids. For a few special cases, isobutane is used for a sensitivity analysis due to its relatively high efficiencies. Our results show that the system has the potential to effectively use low grade thermal sources. System performance depends both on the adopted parameters and working fluid. - Highlights: • Waste heat utilization can reduce emissions of carbon dioxide. • The ORC/VCC cycle can deliver power and/or refrigeration using waste heat. • Efficiencies and size parameters are used for cycle evaluation. • The cycle performance is studied for eight suitable refrigerants. Isobutane is used for a sensitivity analysis. • The work shows that the isobutene cycle is quite promising.

  6. Sputtering graphite coating to improve the elevated-temperature cycling ability of the LiMn2O4 electrode.

    Science.gov (United States)

    Wang, Jiexi; Zhang, Qiaobao; Li, Xinhai; Wang, Zhixing; Guo, Huajun; Xu, Daguo; Zhang, Kaili

    2014-08-14

    To improve the cycle performance of LiMn2O4 at elevated temperature, a graphite layer is introduced to directly cover the surface of a commercial LiMn2O4-based electrode via room-temperature DC magnetron sputtering. The as-modified cathodes display improved capacity retention as compared to the bare LiMn2O4 cathode (BLMO) at 55 °C. When sputtering graphite for 30 min, the sample shows the best cycling performance at 55 °C, maintaining 96.2% capacity retention after 200 cycles. Reasons with respect to the graphite layer for improving the elevated-temperature performance of LiMn2O4 are systematically investigated via the methods of cyclic voltammetry, electrochemical impedance spectroscopy, X-ray photoelectron spectrometry, scanning and transmission electron microscopy, X-ray diffraction and inductively coupled plasma-atomic emission spectrometry. The results demonstrate that the graphite coated LiMn2O4 cathode has much less increased electrode polarization and electrochemical impedance than BLMO during the elevated-temperature cycling process. Furthermore, the graphite layer is able to alleviate the severe dissolution of manganese ions into the electrolyte and mitigate the morphological and structural degradation of LiMn2O4 during cycling. A model for the electrochemical kinetics process is also suggested for explaining the roles of the graphite layer in suppressing the Mn dissolution.

  7. The effect of extrinsic motivation on cycle time trial performance.

    Science.gov (United States)

    Hulleman, Michiel; De Koning, Jos J; Hettinga, Florentina J; Foster, Carl

    2007-04-01

    Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. Well-trained recreational cyclists (N=7) completed four 1500-m laboratory time trials including a practice trial, two self-paced trials, and a trial where a monetary reward was offered. Time, total power output, power output attributable to aerobic and anaerobic metabolic sources, VO2, and HR were measured. The time required for the second, third, and last (extrinsically motivated) time trials was 133.1 +/- 2.1, 134.1 +/- 3.4, and 133.6 +/- 3.0 s, respectively, and was not different (P>0.05). There were no differences for total (396 +/- 19, 397 +/- 23, and 401 +/- 17 W), aerobic (253 +/- 12, 254 +/- 10, and 246 +/- 13 W), and anaerobic (143 +/- 14, 143 +/- 21, and 155 +/- 11 W) power output. The highest VO2 was not different over consecutive time trials (3.76 +/- 0.19, 3.73 +/- 0.16, and 3.71 +/- 0.22 L x min(-1)). When ranked by performance, without reference to the extrinsic motivation (131.9 +/- 2.4, 133.4 +/- 2.4, and 135.4 +/- 2.5 s), there was a significant difference for the first 100 m and from 100 to 300 m in power output, with a larger total power (560 +/- 102, 491 +/- 82, and 493 +/- 93; and 571 +/- 94, 513 +/- 41, and 484 +/- 88 W) and power attributable to anaerobic sources (446 +/- 100, 384 +/- 80, and 324 +/- 43; and 381 +/- 87, 383 +/- 90, and 289 +/- 91 W) for the fastest trial. Extrinsic motivation did not change the time trial performance, suggesting that 1500-m performance is extremely stable and not readily changeable with simple external motivation. The results suggest that spontaneous improvement in performance for time trials of this duration is attributable to greater early power output, which is primarily attributable to anaerobic metabolic sources.

  8. Rapid-fire improvement with short-cycle kaizen.

    Science.gov (United States)

    Heard, E

    1999-05-01

    Continuous improvement is an attractive idea, but it is typically more myth than reality. SCK is no myth. It delivers dramatic improvements in traditional measures quickly. SCK accomplishes this via kaizens: rapid, repeated, time-compressed changes for the better in bite-sized chunks of the business.

  9. Creating a Cycle of Continuous Improvement through Instructional Rounds

    Science.gov (United States)

    Meyer-Looze, Catherine L.

    2015-01-01

    Instructional Rounds is a continuous improvement strategy that focuses on the technical core of educational systems as well as educators collaborating side-by-side. Concentrating on collective learning, this process only makes sense within an overall strategy of improvement. This case study examined the Instructional Rounds process in a northern…

  10. Performance investigation of advanced adsorption desalination cycle with condenser-evaporator heat recovery scheme

    KAUST Repository

    Thu, Kyaw

    2013-01-01

    Energy or heat recovery schemes are keys for the performance improvement of any heat-activated cycles such as the absorption and adsorption cycles. We present two innovative heat recovery schemes between the condensing and evaporating units of an adsorption desalination (AD) cycle. By recovering the latent heat of condenser and dumping it into the evaporative process of the evaporator, it elevates the evaporating temperature and hence the adsorption pressure seen by the adsorbent. From isotherms, this has an effect of increasing the vapour uptake. In the proposed configurations, one approach is simply to have a run-about water circuit between the condenser and the evaporator and a pump is used to achieve the water circulation. This run-around circuit is a practical method for retrofitting purposes. The second method is targeted towards a new AD cycle where an encapsulated condenser-evaporator unit is employed. The heat transfer between the condensing and evaporative vapour is almost immediate and the processes occur in a fully integrated vessel, thereby minimizing the heat transfer resistances of heat exchangers. © 2013 Desalination Publications.

  11. Evaluation of ejector performance for an organic Rankine cycle combined power and cooling system

    International Nuclear Information System (INIS)

    Zhang, Kun; Chen, Xue; Markides, Christos N.; Yang, Yong; Shen, Shengqiang

    2016-01-01

    Highlights: • The performance of an ejector in an Organic Rankine Cycle and ejector refrigeration cycle (EORC) was evaluated. • The achieved entrainment ratio and COP of an EORC system is affected significantly by the evaporator conditions (such as temperature, pressure and flow rate). • An optimum distance of 6 mm nozzle position was found that ensures a maximum entrainment ratio, the best efficiency and lowest loss in the ejector. • A reduced total pressure loss between the nozzle inlet and exit leads to a lower energy loss, a higher entrainment ratio and better overall ejector performance. - Abstract: Power-generation systems based on organic Rankine cycles (ORCs) are well suited and increasingly employed in the conversion of thermal energy from low temperature heat sources to power. These systems can be driven by waste heat, for example from various industrial processes, as well as solar or geothermal energy. A useful extension of such systems involves a combined ORC and ejector-refrigeration cycle (EORC) that is capable, at low cost and complexity, of producing useful power while having a simultaneous capacity for cooling that is highly desirable in many applications. A significant thermodynamic loss in such a combined energy system takes place in the ejector due to unavoidable losses caused by irreversible mixing in this component. This paper focuses on the flow and transport processes in an ejector, in order to understand and quantify the underlying reasons for these losses, as well as their sensitivity to important design parameters and operational variables. Specifically, the study considers, beyond variations to the geometric design of the ejector, also the role of changing the external conditions across this component and how these affect its performance; this is not only important in helping develop ejector designs in the first instance, but also in evaluating how the performance may shift (in fact, deteriorate) quantitatively when the device

  12. Field-measured drag area is a key correlate of level cycling time trial performance

    Directory of Open Access Journals (Sweden)

    James E. Peterman

    2015-08-01

    Full Text Available Drag area (Ad is a primary factor determining aerodynamic resistance during level cycling and is therefore a key determinant of level time trial performance. However, Ad has traditionally been difficult to measure. Our purpose was to determine the value of adding field-measured Ad as a correlate of level cycling time trial performance. In the field, 19 male cyclists performed a level (22.1 km time trial. Separately, field-determined Ad and rolling resistance were calculated for subjects along with projected frontal area assessed directly (AP and indirectly (Est AP. Also, a graded exercise test was performed to determine $\\dot {V}{O}_{2}$V̇O2 peak, lactate threshold (LT, and economy. $\\dot {V}{O}_{2}$V̇O2 peak ($\\mathrm{l}~\\min ^{-1}$lmin−1 and power at LT were significantly correlated to power measured during the time trial (r = 0.83 and 0.69, respectively but were not significantly correlated to performance time (r = − 0.42 and −0.45. The correlation with performance time improved significantly (p < 0.05 when these variables were normalized to Ad. Of note, Ad alone was better correlated to performance time (r = 0.85, p < 0.001 than any combination of non-normalized physiological measure. The best correlate with performance time was field-measured power output during the time trial normalized to Ad (r = − 0.92. AP only accounted for 54% of the variability in Ad. Accordingly, the correlation to performance time was significantly lower using power normalized to AP (r = − 0.75 or Est AP (r = − 0.71. In conclusion, unless normalized to Ad, level time trial performance in the field was not highly correlated to common laboratory measures. Furthermore, our field-measured Ad is easy to determine and was the single best predictor of level time trial performance.

  13. Performance comparison of three trigeneration systems using organic rankine cycles

    International Nuclear Information System (INIS)

    Al-Sulaiman, Fahad A.; Hamdullahpur, Feridun; Dincer, Ibrahim

    2011-01-01

    In this paper, energetic performance comparison of three trigeneration systems is presented. The systems considered are SOFC-trigeneration, biomass-trigeneration, and solar-trigeneration systems. This study compares the performance of the systems considered when there is only electrical power and the efficiency improvement of these systems when there is trigeneration. Different key output parameters are examined: energy efficiency, net electrical power, electrical to heating and cooling ratios, and (GHG) GHG (greenhouse gas) emissions. This study shows that the SOFC-trigeneration system has the highest electrical efficiency among the three systems. Alternatively, when trigeneration is used, the efficiencies of all three systems considered increase considerably. The maximum trigeneration efficiency of the SOFC-trigeneration system is around 76% while it is around 90% for the biomass-trigeneration system. On the other hand, the maximum trigeneration efficiencies of the solar-trigeneration system is around 90% for the solar mode, 45% for storage and storage mode, and 41% for the storage mode. In addition, this study shows that the emissions of CO 2 in kg per MWh of electrical power are high for the biomass-trigeneration and SOFC-trigeneration systems. However, by considering the emissions per MWh of trigeneration, their values drop to less than one fourth. -- Highlights: → We have compared the energetic performance of three potential trigeneration systems. → These systems are SOFC, biomass, and solar-trigeneration systems. → The SOFC-trigeneration system has the highest electrical efficiency. → The trigeneration efficiencies of the biomass-trigeneration system and solar mode of the solar-trigeneration system are the highest. → The CO 2 emissions per MWh of combined cooling, heating, and power production drop significantly when trigeneration is used.

  14. Potential improvements of supercritical recompression CO2 Brayton cycle by mixing other gases for power conversion system of a SFR

    International Nuclear Information System (INIS)

    Jeong, Woo Seok; Lee, Jeong Ik; Jeong, Yong Hoon

    2011-01-01

    Highlights: → S-CO 2 cycle could be enhanced by shifting the critical point of working fluids using gas mixture. → In-house cycle code was developed to analyze supercritical Brayton cycles with gas mixture. → Gas mixture candidates were selected through a screening process: CO 2 mixing with N 2 , O 2 , He, and Ar. → CO 2 -He binary mixture shows the highest cycle efficiency increase. → Lowering the critical temperature and critical pressure of the coolant has a positive effect on the total cycle efficiency. - Abstract: A sodium-cooled fast reactor (SFR) is one of the strongest candidates for the next generation nuclear reactor. However, the conventional design of a SFR concept with an indirect Rankine cycle is subjected to a possible sodium-water reaction. To prevent any hazards from sodium-water reaction, a SFR with the Brayton cycle using Supercritical Carbon dioxide (S-CO 2 ) as the working fluid can be an alternative approach to improve the current SFR design. However, the S-CO 2 Brayton cycle is more sensitive to the critical point of working fluids than other Brayton cycles. This is because compressor work is significantly decreased slightly above the critical point due to high density of CO 2 near the boundary between the supercritical state and the subcritical state. For this reason, the minimum temperature and pressure of cycle are just above the CO 2 critical point. In other words, the critical point acts as a limitation of the lowest operating condition of the cycle. In general, lowering the rejection temperature of a thermodynamic cycle can increase the efficiency. Therefore, changing the critical point of CO 2 can result in an improvement of the total cycle efficiency with the same cycle layout. A small amount of other gases can be added in order to change the critical point of CO 2 . The direction and range of the critical point variation of CO 2 depends on the mixed component and its amount. Several gases that show chemical stability with

  15. A stage-wise approach to exploring performance effects of cycle time reduction

    NARCIS (Netherlands)

    Eling, K.; Langerak, F.; Griffin, A.

    2013-01-01

    Research on reducing new product development (NPD) cycle time has shown that firms tend to adopt different cycle time reduction mechanisms for different process stages. However, the vast majority of previous studies investigating the relationship between new product performance and NPD cycle time

  16. Cloud Computing for Maintenance Performance Improvement

    OpenAIRE

    Kour, Ravdeep; Karim, Ramin; Parida, Aditya

    2013-01-01

    Cloud Computing is an emerging research area. It can be utilised for acquiring an effective and efficient information logistics. This paper uses cloud-based technology for the establishment of information logistics for railway system which requires information based on data from different data sources (e.g. railway maintenance, railway operation, and railway business data). In order to improve the performance of the maintenance process relevant data from various sources need to be acquired, f...

  17. Clinical audit training improves undergraduates' performance in root canal therapy.

    Science.gov (United States)

    Fong, J Y M; Tan, V J H; Lee, J R; Tong, Z G M; Foong, Y K; Tan, J M E; Parolia, A; Pau, A

    2017-12-20

    To evaluate the effectiveness of clinical audit-feedback cycle as an educational tool in improving the technical quality of root canal therapy (RCT) and compliance with record keeping performed by dental undergraduates. Clinical audit learning was introduced in Year 3 of a 5-year curriculum for dental undergraduates. During classroom activities, students were briefed on clinical audit, selected their audit topics in groups of 5 or 6 students, and prepared and presented their audit protocols. One chosen topic was RCT, in which 3 different cohorts of Year 3 students conducted retrospective audits of patients' records in 2012, 2014 and 2015 for their compliance with recommended record keeping criteria and their performance in RCT. Students were trained by and calibrated against an endodontist (κ ≥ 0.8). After each audit, the findings were reported in class, and recommendations were made for improvement in performance of RCT and record keeping. Students' compliance with published guidelines was presented and their RCT performances in each year were compared using the chi-square test. Overall compliance with of record keeping guidelines was 44.1% in 2012, 79.6% in 2014 and 94.6% in 2015 (P = .001). In the 2012 audit, acceptable extension, condensation and the absence of mishap were observed in 72.4, 75.7% and 91.5%; in the 2014 audit, 95.1%, 64.8% and 51.4%; and in 2015 audit, 96.4%, 82.1% and 92.8% of cases, respectively. In 2015, 76.8% of root canal fillings met all 3 technical quality criteria when compared to 48.6% in 2014 and 44.7% in 2012 (P = .001). Clinical audit-feedback cycle is an effective educational tool for improving dental undergraduates' compliance with record keeping and performance in the technical quality of RCT. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Off-design performance analysis of a solar-powered organic Rankine cycle

    International Nuclear Information System (INIS)

    Wang, Jiangfeng; Yan, Zhequan; Zhao, Pan; Dai, Yiping

    2014-01-01

    Highlights: • Solar-powered organic Rankine cycle with CPC and thermal storage unit is studied. • Off-design performances encountering the changes of key parameters are examined. • Off-design performance is analyzed over a whole day and in different months. - Abstract: Performance evaluation of a thermodynamic system under off-design conditions is very important for reliable and cost-effective operation. In this study, an off-design model of an organic Rankine cycle driven by solar energy is established with compound parabolic collector (CPC) to collect the solar radiation and thermal storage unit to achieve the continuous operation of the overall system. The system off-design behavior is examined under the change in environment temperature, as well as thermal oil mass flow rates of vapor generator and CPC. In addition, the off-design performance of the system is analyzed over a whole day and in different months. The results indicate that a decrease in environment temperature, or the increases in thermal oil mass flow rates of vapor generator and CPC could improve the off-design performance. The system obtains the maximum average exergy efficiency in December and the maximum net power output in June or in September. Both the net power output and the average exergy efficiency reach minimum values in August

  19. Substrate Utilization and Cycling Performance Following Palatinose™ Ingestion: A Randomized, Double-Blind, Controlled Trial

    Directory of Open Access Journals (Sweden)

    Daniel König

    2016-06-01

    Full Text Available (1 Objective: To compare the effects of isomaltulose (Palatinose™, PSE vs. maltodextrin (MDX ingestion on substrate utilization during endurance exercise and subsequent time trial performance; (2 Methods: 20 male athletes performed two experimental trials with ingestion of either 75 g PSE or MDX 45 min before the start of exercise. The exercise protocol consisted of 90 min cycling (60% VO2max followed by a time trial; (3 Results: Time trial finishing time (−2.7%, 90% CI: ±3.0%, 89% likely beneficial; p = 0.147 and power output during the final 5 min (+4.6%, 90% CI: ±4.0%, 93% likely beneficial; p = 0.053 were improved with PSE compared with MDX. The blood glucose profile differed between trials (p = 0.013 with PSE resulting in lower glycemia during rest (95%–99% likelihood and higher blood glucose concentrations during exercise (63%–86% likelihood. In comparison to MDX, fat oxidation was higher (88%–99% likelihood; p = 0.005 and carbohydrate oxidation was lower following PSE intake (85%–96% likelihood; p = 0.002. (4 Conclusion: PSE maintained a more stable blood glucose profile and higher fat oxidation during exercise which resulted in improved cycling performance compared with MDX. These results could be explained by the slower availability and the low-glycemic properties of Palatinose™ allowing a greater reliance on fat oxidation and sparing of glycogen during the initial endurance exercise.

  20. Hydrogen Sorption Performance of Pure Magnesium during Continued Cycling

    DEFF Research Database (Denmark)

    Vigeholm, B.; Kjøller, John; Larsen, B.

    1983-01-01

    Preliminary investigations of the hydrogen absorption - desorption by commercially pure magnesium powder under continuous operation show little or no reduction in hydrogen capacity up to 70 cycles and high temperature exposure exceeding 1200 h. Absorption was studied at 260°–425°C and hydrogen...

  1. Thermodynamic performance analysis and optimization of DMC (Dual Miller Cycle) cogeneration system by considering exergetic performance coefficient and total exergy output criteria

    International Nuclear Information System (INIS)

    Ust, Yasin; Arslan, Feyyaz; Ozsari, Ibrahim; Cakir, Mehmet

    2015-01-01

    Miller cycle engines are one of the popular engine concepts that are available for improving performance, reducing fuel consumption and NO x emissions. There are many research studies that investigated the modification of existing conventional engines for operation on a Miller cycle. In this context, a comparative performance analysis and optimization based on exergetic performance criterion, total exergy output and exergy efficiency has been carried out for an irreversible Dual–Miller Cycle cogeneration system having finite-rate of heat transfer, heat leak and internal irreversibilities. The EPC (Exergetic Performance Coefficient) criterion defined as the ratio of total exergy output to the loss rate of availability. Performance analysis has been also extended to the Otto–Miller and Diesel-Miller cogeneration cycles which may be considered as two special cases of the Dual–Miller cycle. The effect of the design parameters such as compression ratio, pressure ratio, cut-off ratio, Miller cycle ratio, heat consumer temperature ratio, allocation ratio and the ratio of power to heat consumed have also been investigated. The results obtained from this paper will provide guidance for the design of Dual–Miller Cycle cogeneration system and can be used for selection of optimal design parameters. - Highlights: • A thermodynamic performance estimation tool for DM cogeneration cycle is presented. • Using the model two special cases OM and dM cogeneration cycles can be analyzed. • The effects of r M , ψ, χ 2 and R have been investigated. • The results evaluate exergy output and environmental aspects together.

  2. Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

    KAUST Repository

    Ng, Kim Choon; Thu, Kyaw; Oh, Seungjin; Ang, Li; Shahzad, Muhammad Wakil; Ismail, Azhar Bin

    2015-01-01

    -driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent

  3. Quantum degeneracy effect on performance of irreversible Otto cycle with ideal Bose gas

    International Nuclear Information System (INIS)

    Wu Feng; Chen Lingen; Sun Fengrui; Wu Chih; Guo Fangzhong; Li Qing

    2006-01-01

    An Otto cycle working with an ideal Bose gas is called a Bose Otto cycle. The internal irreversibility of the cycle is included in the factors of internal irreversibility degree. The quantum degeneracy effect on the performance of the cycle is investigated based on quantum statistical mechanics and thermodynamics. Variations of the maximum work output ratio R W and the efficiency ratio y with temperature ratio τ are examined, which reveal the influence of the quantum degeneracy of the working substance on the performance of a Bose Otto cycle. It is shown that the results obtained herein are valid under both classical and quantum ideal gas conditions

  4. Heat transfer effects on the performance of an air standard Dual cycle

    International Nuclear Information System (INIS)

    Hou, S.-S.

    2004-01-01

    There are heat losses during the cycle of a real engine that are neglected in ideal air standard analysis. In this paper, the effects of heat transfer on the net work output and the indicated thermal efficiency of an air standard Dual cycle are analyzed. Heat transfer from the unburned mixture to the cylinder walls has a negligible effect on the performance for the compression process. Additionally, the heat transfer rates to the cylinder walls during combustion are the highest and extremely important. Therefore, we assume that the compression and power processes proceed instantaneously so that they are reversible adiabatics, and the heat losses during the heat rejection process can be neglected. The heat loss through the cylinder wall is assumed to occur only during combustion and is further assumed to be proportional to the average temperature of both the working fluid and the cylinder wall. The results show that the net work output versus efficiency characteristics and the maximum net work output and the corresponding efficiency bounds are strongly influenced by the magnitude of the heat transfer. Higher heat transfer to the combustion chamber walls lowers the peak temperature and pressure and reduces the work per cycle and the efficiency. The effects of other parameters, in conjunction with the heat transfer, including combustion constants, cut-off ratio and intake air temperature, are also reported. The results are of importance to provide good guidance for the performance evaluation and improvement of practical Diesel engines

  5. Numerical simulation and experimental validation of internal heat exchanger influence on CO{sub 2} trans-critical cycle performance

    Energy Technology Data Exchange (ETDEWEB)

    Rigola, Joaquim; Ablanque, Nicolas; Perez-Segarra, Carlos D.; Oliva, Assensi [Centre Tecnologic de Transferencia de Calor (CTTC), Universitat Politecnica de Catalunya (UPC), ETSEIAT, C. Colom 11, 08222 Terrassa (Barcelona) (Spain)

    2010-06-15

    The present paper is a numerical and experimental comparative study of the whole vapour compression refrigerating cycle in general, and reciprocating compressors in particular, with the aim of showing the possibilities that CO{sub 2} offers for commercial refrigeration, considering a single-stage trans-critical cycle using semi-hermetic reciprocating compressors under small cooling capacity systems. The present work is focussed on the influence of using an internal heat exchanger (IHX) in order to improve the cycle performance under real working conditions. In order to validate the numerical results, an experimental unit specially designed and built to analyze trans-critical refrigerating equipments considering IHX has been built. Both numerical results and experimental data show reasonable good agreement, while the comparative global values conclude the improvement of cooling capacity and COP when IHX is considered in the CO{sub 2} trans-critical cycle. (author)

  6. Crop improvement using life cycle datasets acquired under field conditions

    Directory of Open Access Journals (Sweden)

    Keiichi eMochida

    2015-09-01

    Full Text Available Crops are exposed to various environmental stresses in the field throughout their life cycle. Modern plant science has provided remarkable insights into the molecular networks of plant stress responses in laboratory conditions, but the responses of different crops to environmental stresses in the field need to be elucidated. Recent advances in omics analytical techniques and information technology have enabled us to integrate data from a spectrum of physiological metrics of field crops. The interdisciplinary efforts of plant science and data science enable us to explore factors that affect crop productivity and identify stress tolerance-related genes and alleles. Here, we describe recent advances in technologies that are key components for data driven crop design, such as population genomics, chronological omics analyses, and computer-aided molecular network prediction. Integration of the outcomes from these technologies will accelerate our understanding of crop phenology under practical field situations and identify key characteristics to represent crop stress status. These elements would help us to genetically engineer designed crops to prevent yield shortfalls because of environmental fluctuations due to future climate change.

  7. Crop improvement using life cycle datasets acquired under field conditions.

    Science.gov (United States)

    Mochida, Keiichi; Saisho, Daisuke; Hirayama, Takashi

    2015-01-01

    Crops are exposed to various environmental stresses in the field throughout their life cycle. Modern plant science has provided remarkable insights into the molecular networks of plant stress responses in laboratory conditions, but the responses of different crops to environmental stresses in the field need to be elucidated. Recent advances in omics analytical techniques and information technology have enabled us to integrate data from a spectrum of physiological metrics of field crops. The interdisciplinary efforts of plant science and data science enable us to explore factors that affect crop productivity and identify stress tolerance-related genes and alleles. Here, we describe recent advances in technologies that are key components for data driven crop design, such as population genomics, chronological omics analyses, and computer-aided molecular network prediction. Integration of the outcomes from these technologies will accelerate our understanding of crop phenology under practical field situations and identify key characteristics to represent crop stress status. These elements would help us to genetically engineer "designed crops" to prevent yield shortfalls because of environmental fluctuations due to future climate change.

  8. Thermal performance of Brayton power cycles. A study based on high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Herranz, Luis E.; Linares, Jose I.; Moratilla, Beatriz Y.

    2005-01-01

    Power cycles optimization has become an essential ingredient to achieve sustainability and improve economic competitiveness of forthcoming Generation IV designs. This paper investigates performance of several configurations of direct helium Brayton cycles. An optimum layout is proposed based on multiple intercooled compression stages and in-between turbines reheating: C(IC) 2 HTRTX. Under the hypotheses and approximations made, a 59% is estimated and it increases even further (67%) when the foreseen technological development is considered. A sensitive analysis identified key components and variables for cycle performance. Particular attention is paid to the effect of the extracted gas mass fraction for reheating. It is shown that the C(IC) 2 HTRTX cycle provides a feasible and simple way to operate the power plant the load-follow mode with a very little loss of efficiency. (author)

  9. Effect of lactate supplementation and sodium bicarbonate on 40-km cycling time trial performance.

    Science.gov (United States)

    Northgraves, Matthew J; Peart, Daniel J; Jordan, Christian A; Vince, Rebecca V

    2014-01-01

    The use of nutritional supplements to improve sporting performance and increase training adaptations is commonplace among athletes and is an expanding market in terms of product choice and availability. The purpose of this study was to examine the effects of 2 ergogenic aids with extracellular blood buffering potential, namely sodium bicarbonate (NaHCO3) and a lactate supplement, during a 40-km cycling time trial. Seven recreationally active men (age, 22.3 ± 3.3 years; height, 182.5 ± 6.5 cm; body mass, 79.2 ± 6.3 kg) completed five 40-km cycling time trials, including a familiarization trial in a randomized, blind, double placebo-controlled design. Subjects ingested (a) 300 mg·kg-1 body mass NaHCO3 (BICARB), (b) 45 mg·kg-1 body mass sodium chloride (PL-BICARB) as the placebo for the NaHCO3 trial, (c) 1115 mg lactate (LACTATE), or (d) plain flour as the placebo for the lactate trial (PL-LACTATE) 60 minutes before exercise. There was no significant difference in performance between the 4 conditions (p > 0.05). Although NaHCO3 ingestion induced significant changes in all the acid-base variables (all p 0.05). Subjects in the LACTATE condition did have a significantly higher heart rate (p 0.05) than the other 3 conditions. Neither NaHCO3 nor lactate supplementation seem to improve 40-km cycling time trial performance. However, the potential benefits following LACTATE regarding perceived exertion require further research.

  10. 1-cycle SANEX process development studies performed at Forschungszentrum Juelich

    International Nuclear Information System (INIS)

    Wilden, Andreas; Sypula, Michal; Schreinemachers, Christian; Kluxen, Paul; Modolo, Giuseppe

    2010-01-01

    In the framework of our research activities related to the partitioning of spent nuclear fuel solutions, the direct selective extraction of trivalent actinides from a simulated PUREX raffinate solution (1-cycle SANEX) was studied using a mixture of CyMe 4 BTBP and TODGA. The solvent showed a high selectivity for trivalent actinides with a high lanthanide separation factor. However the co-extraction of some fission products, such as Cu, Ni, Zr, Mo, Pd, Ag and Cd was observed. The extraction of Zr and Mo could be suppressed using oxalic acid but the use of the well-known Pd complexant HEDTA was unsuccessful. During screening experiments with different amino acids, the sulphur-bearing amino acid L-Cysteine showed good complexation of Pd and prevented its extraction into the organic phase without influencing the extraction of trivalent actinides. A strategy for a single-cycle process is proposed within this paper. (authors)

  11. Performance analysis of Brayton cycle system for space power reactor

    International Nuclear Information System (INIS)

    Li Zhi; Yang Xiaoyong; Zhao Gang; Wang Jie; Zhang Zuoyi

    2017-01-01

    The closed Brayton cycle system now is the potential choice as the power conversion system for High Temperature Gas-cooled Reactors because of its high energy conversion efficiency and compact configuration. The helium is the best working fluid for the system for its chemical stability and small neutron absorption cross section. However, the Helium has small mole mass and big specific volume, which would lead to larger pipes and heat exchanger. What's more, the big compressor enthalpy rise of helium would also lead to an unacceptably large number of compressor's stage. For space use, it's more important to satisfy the limit of the system's volume and mass, instead of the requirement of the system's thermal capacity. So Noble-Gas binary mixture of helium and xenon is presented as the working fluid for space Brayton cycle. This paper makes a mathematical model for space Brayton cycle system by Fortran language, then analyzes the binary mixture of helium and xenon's properties and effects on power conversion units of the space power reactor, which would be helpful to understand and design the space power reactor. The results show that xenon would lead to a worse system's thermodynamic property, the cycle's efficiency and specific power decrease as xenon's mole fraction increasing. On the other hand, proper amount of xenon would decrease the enthalpy changes in turbomachines, which would be good for turbomachines' design. Another optimization method – the specific power optimization is also proposed to make a comparison. (author)

  12. ESBWR enhanced flow distribution with optimized orificing and related fuel cycle performance

    International Nuclear Information System (INIS)

    Pearson, G. J.; Karve, A. A.; Fawcett, R. M.

    2012-01-01

    The Economic Simplified Boiling Water Reactor (ESBWR) is GEH's latest Generation III+ reactor design with natural circulation coolant flow and passive safety features. Reliance on natural circulation as the sole means of core coolant driving force results in increased power-to-flow ratio and places increased importance on the efficient distribution of core flow in order to achieve optimum thermal margins and improved fuel cycle efficiency. In addition, the large core size of the ESBWR, containing 1132 bundles, greatly benefits from a more targeted distribution of flow, directing a higher fraction of flow to high power bundles in the 'ring of fire' region of typical BWR loading patterns and a lower fraction of flow to low power bundles on and near the core periphery. Desirable flow distributions can be achieved by modifying the hydraulic resistance of the inlet orifices to preferentially force flow to the targeted region. The inlet orifice is a feature that is incorporated into the fuel support piece of a typical BWR design. The majority of existing forced circulation BWR's rely on only two orifice types - a peripheral orifice located along the outermost row and a central orifice in all other locations. A more optimum distribution of core flow is achievable with the introduction of multiple inlet orifice types. Multi-zone orifice layouts comprised of two, three and four types have been evaluated for the ESBWR. An efficient radial distribution of flow can have a direct beneficial effect on the Minimum Critical Power Ratio (MCPR). An improved multi-zone orifice layout in the ESBWR has the potential of significantly increasing active flow in high power bundles. On average, this flow increase corresponds to a noteworthy MCPR improvement. Additional MCPR margin may be used to enhance operating flexibility and to achieve reduced fuel cycle costs over the plant lifetime. Combined with GNF's latest high performance fuel design for the ESBWR, GNF2E, and improved loading

  13. Improving ethanol productivity through self-cycling fermentation of yeast: a proof of concept.

    Science.gov (United States)

    Wang, Jie; Chae, Michael; Sauvageau, Dominic; Bressler, David C

    2017-01-01

    The cellulosic ethanol industry has developed efficient strategies for converting sugars obtained from various cellulosic feedstocks to bioethanol. However, any further major improvements in ethanol productivity will require development of novel and innovative fermentation strategies that enhance incumbent technologies in a cost-effective manner. The present study investigates the feasibility of applying self-cycling fermentation (SCF) to cellulosic ethanol production to elevate productivity. SCF is a semi-continuous cycling process that employs the following strategy: once the onset of stationary phase is detected, half of the broth volume is automatically harvested and replaced with fresh medium to initiate the next cycle. SCF has been shown to increase product yield and/or productivity in many types of microbial cultivation. To test whether this cycling process could increase productivity during ethanol fermentations, we mimicked the process by manually cycling the fermentation for five cycles in shake flasks, and then compared the results to batch operation. Mimicking SCF for five cycles resulted in regular patterns with regards to glucose consumption, ethanol titer, pH, and biomass production. Compared to batch fermentation, our cycling strategy displayed improved ethanol volumetric productivity (the titer of ethanol produced in a given cycle per corresponding cycle time) and specific productivity (the amount of ethanol produced per cellular biomass) by 43.1 ± 11.6 and 42.7 ± 9.8%, respectively. Five successive cycles contributed to an improvement of overall productivity (the aggregate amount of ethanol produced at the end of a given cycle per total processing time) and the estimated annual ethanol productivity (the amount of ethanol produced per year) by 64.4 ± 3.3 and 33.1 ± 7.2%, respectively. This study provides proof of concept that applying SCF to ethanol production could significantly increase productivities, which will help strengthen the

  14. SRF Performance of CEBAF After Thermal Cycle to Ambient Temperature

    CERN Document Server

    Rimmer, Robert; Preble, Joseph P; Reece, Charles E

    2005-01-01

    In September 2003, in the wake of Hurricane Isabel, JLab was without power for four days after a tree fell on the main power lines feeding the site. This was long enough to lose insulating vacuum in the cryomodules and cryogenic systems resulting in the whole accelerator warming up and the total loss of the liquid helium inventory. This thermal cycle stressed many of the cryomodule components causing several cavities to become inoperable due to helium to vacuum leaks. At the same time the thermal cycle released years of adsorbed gas from the cold surfaces. Over the next days and weeks this gas was pumped away, the insulating vacuum was restored and the machine was cooled back down and re-commissioned. In a testament to the robustness of SRF technology, only a small loss in energy capability was apparent, although individual cavities had quite different field-emission characteristics compared to before the event. In Summer 2004 a section of the machine was again cycled to room temperature during the long maint...

  15. Error review: Can this improve reporting performance?

    International Nuclear Information System (INIS)

    Tudor, Gareth R.; Finlay, David B.

    2001-01-01

    AIM: This study aimed to assess whether error review can improve radiologists' reporting performance. MATERIALS AND METHODS: Ten Consultant Radiologists reported 50 plain radiographs, in which the diagnoses were established. Eighteen of the radiographs were normal, 32 showed an abnormality. The radiologists were shown their errors and then re-reported the series of radiographs after an interval of 4-5 months. The accuracy of the reports to the established diagnoses was assessed. Chi-square test was used to calculate the difference between the viewings. RESULTS: On re-reporting the radiographs, seven radiologists improved their accuracy score, two had a lower score and one radiologist showed no score difference. Mean accuracy pre-education was 82.2%, (range 78-92%) and post-education was 88%, (range 76-96%). Individually, two of the radiologists showed a statistically significant improvement post-education (P < 0.01,P < 0.05). Assessing the group as a whole, there was a trend for improvement post-education but this did not reach statistical significance. Assessing only the radiographs where errors were made on the initial viewing, for the group as a whole there was a 63% improvement post-education. CONCLUSION: We suggest that radiologists benefit from error review, although there was not a statistically significant improvement for the series of radiographs in total. This is partly explained by the fact that some radiologists gave incorrect responses post-education that had initially been correct, thus masking the effect of the educational intervention. Tudor, G.R. and Finlay, D.B. (2001

  16. Cleanliness criteria to improve steam generator performance

    International Nuclear Information System (INIS)

    Schwarz, T.; Bouecke, R.; Odar, S.

    2005-01-01

    High steam generator performance is a prerequisite for high plant availability and possible life time extension. The major opponent to that is corrosion and fouling of the heating tubes. Such steam generator degradation problems arise from the continuous ingress of non-volatile contaminants, i.e. corrosion products and salt impurities may accumulate in the steam generators. These impurities have their origin in the secondary side systems. The corrosion products generally accumulate in the steam generators and form deposits not only in the flow restricted areas, such as on top of tube sheet and tube support structure, but also build scales on the steam generator heating tubes. In addition, the tube scales in general affect the steam generator thermal performance, which ultimately causes a reduction of power output. The most effective ways of counteracting all these degradation problems, and thus of improving the steam generator performance is to keep them in clean conditions or, if judged necessary, to plan cleaning measures such as mechanical tube sheet lancing or chemical cleaning. This paper presents a methodology how to assess the cleanliness condition of a steam generator by bringing together all available operational and inspection data such as thermal performance and water chemistry data. By means of this all-inclusive approach the cleanliness condition is quantified in terms of a fouling index. The fouling index allows to monitor the condition of a specific steam generator, compare it to other plants and, finally, to serve as criterion for cleaning measures such as chemical cleaning. The application of the cleanliness criteria and the achieved field results with respect to improvements of steam generator performance will be presented. (author)

  17. Signal Processing for Improved Wireless Receiver Performance

    DEFF Research Database (Denmark)

    Christensen, Lars P.B.

    2007-01-01

    This thesis is concerned with signal processing for improving the performance of wireless communication receivers for well-established cellular networks such as the GSM/EDGE and WCDMA/HSPA systems. The goal of doing so, is to improve the end-user experience and/or provide a higher system capacity...... by allowing an increased reuse of network resources. To achieve this goal, one must first understand the nature of the problem and an introduction is therefore provided. In addition, the concept of graph-based models and approximations for wireless communications is introduced along with various Belief...... Propagation (BP) methods for detecting the transmitted information, including the Turbo principle. Having established a framework for the research, various approximate detection schemes are discussed. First, the general form of linear detection is presented and it is argued that this may be preferable...

  18. Restructuring primary care for performance improvement.

    Science.gov (United States)

    Fawcett, Kenneth J; Brummel, Stacy; Byrnes, John J

    2009-01-01

    Primary care practices can no longer consider ongoing quality assessment and management processes to be optional. There are ever-increasing demands from any number of interested parties for objectively measured proof of outcomes and quality of care. Primary Care Partners (PCP), a 16-site ambulatory affiliate of the Spectrum Health system in Grand Rapids, Michigan, began such a continuous quality improvement (CQI) effort in 2005. The intent was to develop an ongoing systematic process that would raise its performance potential and improve patient outcomes in the areas of chronic disease management and preventive services. This article describes the partnerships PCP established, specific benchmarks and measurements used, processes utilized, and results to date. This could be used as a roadmap for other primary care systems that are working to establish CQI in their daily operations.

  19. Frameworks for improvement: clinical audit, the plan-do-study-act cycle and significant event audit.

    Science.gov (United States)

    Gillam, Steve; Siriwardena, A Niroshan

    2013-01-01

    This is the first in a series of articles about quality improvement tools and techniques. We explore common frameworks for improvement, including the model for improvement and its application to clinical audit, plan-do-study-act (PDSA) cycles and significant event analysis (SEA), examining the similarities and differences between these and providing examples of each.

  20. Improved performance of the Sao Paulo Pelletron

    International Nuclear Information System (INIS)

    Sala, O.; Stier, M.; Acquadro, J.C.

    1981-01-01

    The Sao Paulo Pelletron was the first Pelletron constructed by the NEC and also the first to become operational at the end of 1971. Although the Herb Pelletron design was demonstrated from the beginning to be very good (later this was proven by the successful operation of several larger Pelletrons) our machine did suffer from defects in engineering which limited its performance and its application as a reliable tool for research in nuclear physics. This paper describes some of the improvements which we have introduced to increase the reliability of our Pelletron as a research tool in the University. (orig.)

  1. Dynamic performance of a combined gas turbine and air bottoming cycle plant for off-shore applications

    DEFF Research Database (Denmark)

    Benato, Alberto; Pierobon, Leonardo; Haglind, Fredrik

    2014-01-01

    and a combined gas turbine coupled with an air bottoming cycle plant. The case study is the Draugen off-shore oil and gas platform, located in the North Sea, Norway. The normal electricity demand is 19 MW, currently covered by two gas turbines generating each 50% of the power demand, while the third turbine......When the Norwegian government introduced the CO2 tax for hydrocarbon fuels, the challenge became to improve the performance of off-shore power systems. An oil and gas platform typically operates on an island (stand-alone system) and the power demand is covered by two or more gas turbines. In order...... to improve the plant performance, a bottoming cycle unit can be added to the gas turbine topping module, thus constituting a combined cycle plant. This paper aims at developing and testing the numerical model simulating the part-load and dynamic behavior of a novel power system, composed of two gas turbines...

  2. Model improvements for tritium transport in DEMO fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Santucci, Alessia, E-mail: alessia.santucci@enea.it [Unità Tecnica Fusione – ENEA C. R. Frascati, Via E. Fermi 45, 00044 Frascati (Roma) (Italy); Tosti, Silvano [Unità Tecnica Fusione – ENEA C. R. Frascati, Via E. Fermi 45, 00044 Frascati (Roma) (Italy); Franza, Fabrizio [Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2015-10-15

    Highlights: • T inventory and permeation of DEMO blankets have been assessed under pulsed operation. • 1-D model for T transport has been developed for the HCLL DEMO blanket. • The 1-D model evaluated T partial pressure and T permeation rate radial profiles. - Abstract: DEMO operation requires a large amount of tritium, which is directly produced inside the reactor by means of Li-based breeders. During its production, recovering and purification, tritium comes in contact with large surfaces of hot metallic walls, therefore it can permeate through the blanket cooling structure, reach the steam generator and finally the environment. The development of dedicated simulation tools able to predict tritium losses and inventories is necessary to verify the accomplishment of the accepted tritium environmental releases as well as to guarantee a correct machine operation. In this work, the FUS-TPC code is improved by including the possibility to operate in pulsed regime: results in terms of tritium inventory and losses for three pulsed scenarios are shown. Moreover, the development of a 1-D model considering the radial profile of the tritium generation is described. By referring to the inboard segment on the equatorial axis of the helium-cooled lithium–lead (HCLL) blanket, preliminary results of the 1-D model are illustrated: tritium partial pressure in Li–Pb and tritium permeation in the cooling and stiffening plates by assuming several permeation reduction factor (PRF) values. Future improvements will consider the application of the model to all segments of different blanket concepts.

  3. The effects of Red Bull energy drink compared with caffeine on cycling time-trial performance.

    Science.gov (United States)

    Quinlivan, Alannah; Irwin, Christopher; Grant, Gary D; Anoopkumar-Dukie, Sheilandra; Skinner, Tina; Leveritt, Michael; Desbrow, Ben

    2015-10-01

    This study investigated the ergogenic effects of a commercial energy drink (Red Bull) or an equivalent dose of anhydrous caffeine in comparison with a noncaffeinated control beverage on cycling performance. Eleven trained male cyclists (31.7 ± 5.9 y 82.3 ± 6.1 kg, VO2max = 60.3 ± 7.8 mL · kg-1 · min-1) participated in a double-blind, placebo-controlled, crossover-design study involving 3 experimental conditions. Participants were randomly administered Red Bull (9.4 mL/kg body mass [BM] containing 3 mg/kg BM caffeine), anhydrous caffeine (3 mg/kg BM given in capsule form), or a placebo 90 min before commencing a time trial equivalent to 1 h cycling at 75% peak power output. Carbohydrate and fluid volumes were matched across all trials. Performance improved by 109 ± 153 s (2.8%, P = .039) after Red Bull compared with placebo and by 120 ± 172 s (3.1%, P = .043) after caffeine compared with placebo. No significant difference (P > .05) in performance time was detected between Red Bull and caffeine treatments. There was no significant difference (P > .05) in mean heart rate or rating of perceived exertion among the 3 treatments. This study demonstrated that a moderate dose of caffeine consumed as either Red Bull or in anhydrous form enhanced cycling time-trial performance. The ergogenic benefits of Red Bull energy drink are therefore most likely due to the effects of caffeine, with the other ingredients not likely to offer additional benefit.

  4. Improved Cycling Stability of Cobalt-free Li-rich Oxides with a Stable Interface by Dual Doping

    International Nuclear Information System (INIS)

    Xie, Dongjiu; Li, Guangshe; Li, Qi; Fu, Chaochao; Fan, Jianming; Li, Liping

    2016-01-01

    Highlights: • Cobalt-free Na_xLi_1_._2_-_xMn_0_._6_-_xAl_xNi_0_._2O_2 oxides are prepared by a sol-gel method. • Dual-doping strengthens the covalence of Mn-O bonds and suppresses the side reactions between cathode and electrolyte. • Doped cathode has a capacity retention over 92.2% after 100 cycles at a high temperature of 55 °C. - Abstract: Li-rich cobalt-free oxides, popularly used as a cathode with high capacity in lithium ion battery, always suffer from poor cycling stability between 2.0 and 4.8 V vs Li"+/Li, especially when cycled at high temperatures (>50 °C). To overcome this issue, Na"+ and Al"3"+ dual-doped Na_xLi_1_._2_-_xMn_0_._6_-_xAl_xNi_0_._2O_2 Li-rich cathode is prepared in this study. It is shown that the side reactions between cathode and electrolyte during cycling are suppressed. The improved cycling performance is observed for all of the doped samples, among which the sample with x = 0.03 exhibits the highest capacity retention of 86.1% after 200 cycles between 2.0 and 4.8 V at 2C (1C = 200 mA g"−"1) and shows a remarkable cycling stability, even at a high temperature of 55 °C (a capacity retention of 92.2% after 100 cycles). Moreover, the average voltage of the sample with x = 0.03 after 100 cycles at 0.5C remains at 3.11 V with a retention ratio of 86.6%. This work provides a new strategy to develop Li-rich cobalt-free cathodes with excellent cycling stability for lithium ion batteries at high temperatures.

  5. Improving human performance: Industry factors influencing the ability to perform

    Directory of Open Access Journals (Sweden)

    Güera Massyn Romo

    2013-03-01

    Full Text Available Learning interventions and new technologies that aim to improve human performance must take cognisance of industry factors inhibiting human performance. The dynamic and fast pace nature of the Information and Communication Technologies (ICT and the engineering industries do not lend themselves to proper skills planning and management. These industries experience real skills gaps, to some of which they contribute by themselves. This study reports on these performance-inhibiting factors such as the underutilisation of available skills, tolerance for individual preferences, and dynamically, and informally refining a role objective while an employee is occupying a certain role. The important professional skills required by individuals to cope with these real life factors are also explored in the skills gaps management context. Moreover, these industries need a profile they refer to as Special Forces, which denotes a high calibre of worker that possesses well-developed professional skills whilst having advanced technical expertise and sufficient experience. This resource profile is required largely due to the poor management of human resource processes in practice and the current reported lack of adequate skills. Furthermore, this study refers to the recent lack of a working definition for these Special Forces leading to the omitted active development of these profiles in industry today, which appears to become a key human performance inhibiting factor.

  6. Artificial Astrocytes Improve Neural Network Performance

    Science.gov (United States)

    Porto-Pazos, Ana B.; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

    2011-01-01

    Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function. PMID:21526157

  7. Artificial astrocytes improve neural network performance.

    Directory of Open Access Journals (Sweden)

    Ana B Porto-Pazos

    Full Text Available Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN and artificial neuron-glia networks (NGN to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

  8. Artificial astrocytes improve neural network performance.

    Science.gov (United States)

    Porto-Pazos, Ana B; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

    2011-04-19

    Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

  9. Physiological Correlations with Short, Medium, and Long Cycling Time-Trial Performance

    Science.gov (United States)

    Borszcz, Fernando K.; Tramontin, Artur F.; de Souza, Kristopher M.; Carminatti, Lorival J.; Costa, Vitor P.

    2018-01-01

    Purpose: Several studies have demonstrated that physiological variables predict cycling endurance performance. However, it is still unclear whether the predictors will change over different performance durations. The aim of this study was to assess the correlations between physiological variables and cycling time trials with different durations.…

  10. Anticipated Improvements in Precipitation Physics and Understanding of Water Cycle from GPM Mission

    Science.gov (United States)

    Smith, Eric A.

    2003-01-01

    domestic scientific agencies and institutions, as well as participation by individual scientists from academia, government, and the private sector to fulfill mission goals and to pave the way for what is expected to become an internationally-organized operational global precipitation observing system. Notably, the broad societal applications of GPM are reflected in the United Nation s identification of GPM as a foremost candidate for its Peaceful Uses of Space Program. An overview of the GPM mission design is given, followed by an explanation of its scientific agenda as an outgrowth of making improvements in rain retrieval accuracy, microphysics dexterity, sampling frequency, and global coverage. All of these improvements offer new means to observe variability in precipitation and water cycle fluxes and to achieve improved predictability of weather, climate, and hydrometeorology. Specifically, the scientific agenda of GPM has been designed to leverage the measurement improvements to improve prognostic model performance, particularly quantitative precipitation forecasting and its linked phenomena at short, intermediate, and extended time scales. The talk addresses how GPM measurements will enable better detection of accelerations and decelerations in regional and global water cycle processes and their relationship to climate variability, better impacts of precipitation data assimilation on numerical weather prediction and global climate reanalysis, and better performance from basin scale hydrometeorological models for short and long term flood-drought forecasting and seasonal fresh water resource assessment. These improvements become possible by using more accurate, more microphysically-centric, more frequent, and fully global precipitation observations to achieve better water budget closure and to provide more realistic forcing and assessment of prediction models.

  11. The effect of extrinsic motivation on cycle time trial performance

    NARCIS (Netherlands)

    Hulleman, M.; de Koning, J.J.; Hettinga, F.J.; Foster, C.

    2007-01-01

    PURPOSE: Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. METHODS:

  12. Westinghouse fuel manufacturing systems: a step change in performance improvements

    International Nuclear Information System (INIS)

    Mutyala, Meena

    2009-01-01

    Today's competitive electrical generation industry demands that nuclear power plant operators minimize total operating costs, including fuel cycle cost while maintaining flawless fuel performance. The mission of Westinghouse Nuclear Fuel is to be the industry's most responsive supplier of flawless, value added fuel products and services, as judged by our customers. As nuclear is fast becoming the choice of many countries, existing manufacturing plants and facilities are once again running at full capacity. In this context Westinghouse Nuclear Fuel is committed to deliver a step change in performance improvement worldwide through its manufacturing operations by the introduction of a set of fundamentals collectively named the 'Westinghouse Fuel Manufacturing System' (WFMS), whose key principles are discussed in this paper. (author)

  13. ECONOMICS AND FEASIBILITY OF RANKINE CYCLE IMPROVEMENTS FOR COAL FIRED POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Richard E. Waryasz; Gregory N. Liljedahl

    2004-09-08

    ALSTOM Power Inc.'s Power Plant Laboratories (ALSTOM) has teamed with the U.S. Department of Energy National Energy Technology Laboratory (DOE NETL), American Electric Company (AEP) and Parsons Energy and Chemical Group to conduct a comprehensive study evaluating coal fired steam power plants, known as Rankine Cycles, equipped with three different combustion systems: Pulverized Coal (PC), Circulating Fluidized Bed (CFB), and Circulating Moving Bed (CMB{trademark}). Five steam cycles utilizing a wide range of steam conditions were used with these combustion systems. The motivation for this study was to establish through engineering analysis, the most cost-effective performance potential available through improvement in the Rankine Cycle steam conditions and combustion systems while at the same time ensuring that the most stringent emission performance based on CURC (Coal Utilization Research Council) 2010 targets are met: > 98% sulfur removal; < 0.05 lbm/MM-Btu NO{sub x}; < 0.01 lbm/MM-Btu Particulate Matter; and > 90% Hg removal. The final report discusses the results of a coal fired steam power plant project, which is comprised of two parts. The main part of the study is the analysis of ten (10) Greenfield steam power plants employing three different coal combustion technologies: Pulverized Coal (PC), Circulating Fluidized Bed (CFB), and Circulating Moving Bed (CMB{trademark}) integrated with five different steam cycles. The study explores the technical feasibility, thermal performance, environmental performance, and economic viability of ten power plants that could be deployed currently, in the near, intermediate, and long-term time frame. For the five steam cycles, main steam temperatures vary from 1,000 F to 1,292 F and pressures from 2,400 psi to 5,075 psi. Reheat steam temperatures vary from 1,000 F to 1,328 F. The number of feedwater heaters varies from 7 to 9 and the associated feedwater temperature varies from 500 F to 626 F. The main part of the

  14. Effect of caffeine on cycling time-trial performance in the heat.

    Science.gov (United States)

    Pitchford, Nathan W; Fell, James W; Leveritt, Michael D; Desbrow, Ben; Shing, Cecilia M

    2014-07-01

    The purpose of this investigation was to determine whether a moderate dose of caffeine would improve a laboratory simulated cycling time-trial in the heat. Nine well-trained male subjects (VO2max 64.4±6.8mLmin(-1)kg(-1), peak power output 378±40W) completed one familiarisation and two experimental laboratory simulated cycling time-trials in environmental conditions of 35°C and 25% RH 90min after consuming either caffeine (3mgkg(-1) BW) or placebo, in a double blind, cross-over study. Time-trial performance was faster in the caffeine trial compared with the placebo trial (mean±SD, 3806±359s versus 4079±333s, p=0.06, 90%CI 42-500s, 86% likelihood of benefit, d=-0.79). Caffeine ingestion was associated with small to moderate increases in average heart rate (p=0.178, d=0.39), VO2 (p=0.154, d=0.45), respiratory exchange ratio (p=0.292, d=0.35) and core temperature (p=0.616, d=0.22) when compared to placebo, however, these were not statistically significant. Average RPE during the caffeine supplemented time-trial was not significantly different from placebo (p=0.41, d=-0.13). Caffeine supplementation at 3mgkg(-1) BW resulted in a worthwhile improvement in cycling time-trial performance in the heat. Double-blind cross-over study. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  15. Experimental investigation on the off-design performance of a small-sized humid air turbine cycle

    International Nuclear Information System (INIS)

    Wei, Chenyu; Zang, Shusheng

    2013-01-01

    This research aimed to study the improvement of the gas turbine performance of a humid air turbine (HAT) cycle at low pressure ratio and at low turbine inlet temperature (TIT). To achieve this goal, an off-design performance test investigation was conducted on a small-sized, two-shaft gas turbine test rig. The test rig consisted of a centrifugal compressor, a centripetal turbine, an individual direct flow flame tube, a free power turbine, a dynamometer, and a saturator with structured packing. Two different conditions were considered for the test investigation: in Case I, the control system kept the fuel flow constant at 57 kg/h, and in Case II, the turbine inlet temperature was kept constant at 665 °C. In Case I, when the air humidity ratio increased from 30 g/kg dry air (DA) to 43 g/kg DA, the power output increased by 3 kW. At the same time, the turbine inlet temperature decreased by 19 °C, and the NO x emissions were reduced from 25 ppm to 16 ppm. In Case II, when the air humidity ratio increased from 48 g/kg DA to 57 g/kg DA, the power output increased by 9.5 kW. Based on the actual gas turbine parts, characteristics, and test conditions, the off-design performance of the HAT cycle was calculated. Upon comparing the measured and calculated results, the HAT cycle was found to perform better than the two-shaft cycle in terms of specific work, efficiency, and specific fuel consumption. The effect of performance improvement became more obvious as the air humidity ratio increased. Under the same inlet air flow, turbine inlet temperature, and power output, the surge margin on compressor curves became enlarged as the humidity ratio increased. The off-design performance of a HAT cycle with regenerator was also investigated. The results show that the highest efficiency can be increased by 3.1%, which will greatly improve the gas turbine performance. -- Highlights: ► We built a flexible small-size test rig of HAT cycle gas turbine and the real test data were

  16. Air and fuel supercharge in the performance of a diesel cycle engine

    Directory of Open Access Journals (Sweden)

    Marcelo Silveira de Farias

    Full Text Available ABSTRACT: This paper aimed to evaluate the performance of a Diesel cycle engine, changing the configurations for the air and fuel supply system. Variables analyzed were torque, power, specific fuel consumption and thermal efficiency in four different engine configurations (aspirated, aspirated + service, turbocharged + service and turbocharged. For that, there were dynamometer experiments by power take-off of an agricultural tractor. The experimental outline used was entirely randomized, in a bifatorial design with three repetitions. Results indicated that the engine supercharge, compared to its original configuration, provided a significant increase of torque and power. Only the addition of turbo does not caused a significant effect in the engine performance. Application of turbocharger provides an improvement in the burning of the air/fuel mixture, which favors the increase of engine power and; consequently, reduced the specific fuel consumption.

  17. Thermodynamic performance analysis of a coupled transcritical and subcritical organic Rankine cycle system for waste heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Xi Wu [Zhejiang Ocean University, Zhejian (China); Wang, Xiao Qiong; Li, You Rong; Wu, Chun Mei [Chongqing University, Chongqing (China)

    2015-07-15

    We present a novel coupled organic Rankine cycle (CORC) system driven by the low-grade waste heat, which couples a transcritical organic Rankine cycle with a subcritical organic Rankine cycle. Based on classical thermodynamic theory, a detailed performance analysis on the novel CORC system was performed. The results show that the pressure ratio of the expander is decreased in the CORC and the selection of the working fluids becomes more flexible and abundant. With the increase of the pinch point temperature difference of the internal heat exchanger, the net power output and thermal efficiency of the CORC all decrease. With the increase of the critical temperature of the working fluid, the system performance of the CORC is improved. The net power output and thermal efficiency of the CORC with isentropic working fluids are higher than those with dry working fluids.

  18. The optimal performance of a quantum refrigeration cycle working with harmonic oscillators

    International Nuclear Information System (INIS)

    Lin Bihong; Chen Jincan; Hua Ben

    2003-01-01

    The cycle model of a quantum refrigeration cycle working with many non-interacting harmonic oscillators and consisting of two isothermal and two constant-frequency processes is established. Based on the quantum master equation and semi-group approach, the general performance of the cycle is investigated. Expressions for some important performance parameters, such as the coefficient of performance, cooling rate, power input, and rate of the entropy production, are derived. Several interesting cases are discussed and, especially, the optimal performance of the cycle at high temperatures is discussed in detail. Some important characteristic curves of the cycle, such as the cooling rate versus coefficient of performance curves, the power input versus coefficient of performance curves, the cooling rate versus power input curves, and so on, are presented. The maximum cooling rate and the corresponding coefficient of performance are calculated. Other optimal performances are also analysed. The results obtained here are compared with those of an Ericsson or Stirling refrigeration cycle using an ideal gas as the working substance. Finally, the optimal performance of a harmonic quantum Carnot refrigeration cycle at high temperatures is derived easily

  19. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables......, and endurance time at W90 with FCPR-25, FCPR, and FCPR+25. Power reserve was calculated as the difference between applied power output at a given pedalling rate and peak crank power at this same pedalling rate. W90 was 325 (47) W. FCPR at W90 was 78 (11) rpm, resulting in FCPR-25 being 59 (8) rpm and FCPR+25...... time was negatively related to VO(2max), W90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables...

  20. Life cycle assessment of Italian citrus-based products. Sensitivity analysis and improvement scenarios.

    Science.gov (United States)

    Beccali, Marco; Cellura, Maurizio; Iudicello, Maria; Mistretta, Marina

    2010-07-01

    Though many studies concern the agro-food sector in the EU and Italy, and its environmental impacts, literature is quite lacking in works regarding LCA application on citrus products. This paper represents one of the first studies on the environmental impacts of citrus products in order to suggest feasible strategies and actions to improve their environmental performance. In particular, it is part of a research aimed to estimate environmental burdens associated with the production of the following citrus-based products: essential oil, natural juice and concentrated juice from oranges and lemons. The life cycle assessment of these products, published in a previous paper, had highlighted significant environmental issues in terms of energy consumption, associated CO(2) emissions, and water consumption. Starting from such results the authors carry out an improvement analysis of the assessed production system, whereby sustainable scenarios for saving water and energy are proposed to reduce environmental burdens of the examined production system. In addition, a sensitivity analysis to estimate the effects of the chosen methods will be performed, giving data on the outcome of the study. Uncertainty related to allocation methods, secondary data sources, and initial assumptions on cultivation, transport modes, and waste management is analysed. The results of the performed analyses allow stating that every assessed eco-profile is differently influenced by the uncertainty study. Different assumptions on initial data and methods showed very sensible variations in the energy and environmental performances of the final products. Besides, the results show energy and environmental benefits that clearly state the improvement of the products eco-profile, by reusing purified water use for irrigation, using the railway mode for the delivery of final products, when possible, and adopting efficient technologies, as the mechanical vapour recompression, in the pasteurisation and

  1. How can LCA approaches contribute to improve geo-cycles management

    Science.gov (United States)

    Carreiras, M.; Ferreira, A. J. D.; Esteves, T. C. J.; Delgado, F.; Andrade, F.; Franco, J.; Pereira, C. D.

    2012-04-01

    as a basis for prioritizing industrial technologies, procedures or materials, based on the reduction of impacts. The ECODEEP project intents to contribute to the competitiveness of the national agri-food sector in particular the Central Region of Portugal. Through the development of eco-efficiency tools it allows a more careful management of inputs, optimizing consumption energy and raw materials. ECODEEP seeks to improve the performance of the sector, allowing an improvement of production processes and a reduction of the investment on end-of-line solutions, therefore reducing products costs, which become more competitive, while reducing the impact on geo-cycles and the ecosystems. The overall purpose of this paper is, based on a case study, discuss the use of LCA approach to improve overall competitiveness while reducing the impact over the geo-cycles and the environment in general.

  2. Superior cycle performance of Sn-C/graphene nanocomposite as an anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Liang Shuzhao; Zhu Xuefeng; Lian Peichao; Yang Weishen; Wang Haihui

    2011-01-01

    A novel anode material for lithium-ion batteries, tin nanoparticles coated with carbon embedded in graphene (Sn-C/graphene), was fabricated by hydrothermal synthesis and subsequent annealing. The structure and morphology of the nanocomposite were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The size of the Sn-C nanoparticles is about 50-200 nm. The reversible specific capacity of the nanocomposite is ∼662 mAh g -1 at a specific current of 100 mA g -1 after 100 cycles, even ∼417 mAh g -1 at the high current of 1000 mA g -1 . These results indicate that Sn-C/graphene possesses superior cycle performance and high rate capability. The enhanced electrochemical performances can be ascribed to the characteristic structure of the nanocomposite with both of the graphene and carbon shells, which buffer the volume change of the metallic tin and prevent the detachment and agglomeration of pulverized tin. - Graphical abstract: Tin nanoparticles coated with carbon embedded in graphene have been successfully fabricated by hydrothermal synthesis and subsequent annealing. This nanocomposite as an anode material for lithium-ion batteries exhibits superior cycle performance. Highlights: → A novel Sn-C/graphene nanocomposite as an anode material for lithium-ion batteries. → Carbon coating and graphene improve the cycle performance of the Sn anode material. → Possess large capacity, superior cycle performance, and high rate capability.

  3. MEMS Actuators for Improved Performance and Durability

    Science.gov (United States)

    Yearsley, James M.

    Micro-ElectroMechanical Systems (MEMS) devices take advantage of force-scaling at length scales smaller than a millimeter to sense and interact with directly with phenomena and targets at the microscale. MEMS sensors found in everyday devices like cell-phones and cars include accelerometers, gyros, pressure sensors, and magnetic sensors. MEMS actuators generally serve more application specific roles including micro- and nano-tweezers used for single cell manipulation, optical switching and alignment components, and micro combustion engines for high energy density power generation. MEMS rotary motors are actuators that translate an electric drive signal into rotational motion and can serve as rate calibration inputs for gyros, stages for optical components, mixing devices for micro-fluidics, etc. Existing rotary micromotors suffer from friction and wear issues that affect lifetime and performance. Attempts to alleviate friction effects include surface treatment, magnetic and electrostatic levitation, pressurized gas bearings, and micro-ball bearings. The present work demonstrates a droplet based liquid bearing supporting a rotary micromotor that improves the operating characteristics of MEMS rotary motors. The liquid bearing provides wear-free, low-friction, passive alignment between the rotor and stator. Droplets are positioned relative to the rotor and stator through patterned superhydrophobic and hydrophilic surface coatings. The liquid bearing consists of a central droplet that acts as the motor shaft, providing axial alignment between rotor and stator, and satellite droplets, analogous to ball-bearings, that provide tip and tilt stable operation. The liquid bearing friction performance is characterized through measurement of the rotational drag coefficient and minimum starting torque due to stiction and geometric effects. Bearing operational performance is further characterized by modeling and measuring stiffness, environmental survivability, and high

  4. An improved CO_2-based transcritical Rankine cycle (CTRC) used for engine waste heat recovery

    International Nuclear Information System (INIS)

    Shu, Gequn; Shi, Lingfeng; Tian, Hua; Li, Xiaoya; Huang, Guangdai; Chang, Liwen

    2016-01-01

    Highlights: • Propose an improved CTRC system (PR-CTRC) for engine waste heat recovery. • The PR-CTRC achieves a significant increase in thermodynamic performance. • The PR-CTRC possesses a strong coupling capability for high and low grade waste heat. • The PR-CTRC uses smaller turbine design parameters than ORC systems. • Total cooling load analysis of combined engine and recovery system was conducted. - Abstract: CO_2-based transcritical Rankine cycle (CTRC) is a promising technology for the waste heat recovery of an engine considering its safety and environment friendly characteristics, which also matchs the high temperature of the exhaust gas and satisfies the miniaturization demand of recovery systems. But the traditional CTRC system with a basic configuration (B-CTRC) has a poor thermodynamic performance. This paper introduces an improved CTRC system containing both a preheater and regenerator (PR-CTRC), for recovering waste heat in exhaust gas and engine coolant of an engine, and compares its performance with that of the B-CTRC system and also with that of the traditional excellent Organic Rankine Cycle (ORC) systems using R123 as a working fluid. The utilization rate of waste heat, total cooling load, net power output, thermal efficiency, exergy loss, exergy efficiency and component size have been investigated. Results show that, the net power output of the PR-CTRC could reach up to 9.0 kW for a 43.8 kW engine, which increases by 150% compared with that of the B-CTRC (3.6 kW). The PR-CTRC also improves the thermal efficiency and exergy efficiency of the B-CTRC, with increases of 184% and 227%, respectively. Compared with the ORC system, the PR-CTRC shows the significant advantage of highly recycling the exhaust gas and engine coolant simultaneously due to the special property of supercritical CO_2’s specific heat capacity. The supercritical property of CO_2 also generates a better heat transfer and flowing performances. Meanwhile, the PR

  5. Fabrication of Porous ZnO/Co₃O₄ Composites for Improving Cycling Stability of Supercapacitors.

    Science.gov (United States)

    Su, Dongqing; Zhang, Longmei; Tang, Zehua; Yu, Tingting; Liu, Huili; Zhang, Junhao; Liu, Yuanjun; Yuan, Aihua; Kong, Qinghong

    2018-07-01

    To tackle the issue of poor cycling stability for metal oxide nanoparticles as supercapacitor electrode, porous ZnO/Co3O4 composites were fabricated via solid-state thermolysis of [CoZn(BTC)(NO3)](2H2O)(0.5DMF) under air atmosphere. The results demonstrate that the products are mesoporous polyhedron structure with the diameter of about 10 μm, which are constructed by many interconnected nanocrystals with the sizes of around 20 nm. ZnO/Co3O4 composites as supercapacitor electrode exhibited excellent cyclic stability capacity, showing a maximum specific capacitance of 106.7 F g-1 and a capacity retention of 102.7 F · g-1 after 1000 cycles at 0.5 A · g-1. The superior electrochemical performance was contributed to ZnO/Co3O4 composites with porous structures and small size, which shortened the route of electronic transmission as well as ions insertion and desertion processes. Additionally, the synergetic effect of bimetallic oxides improved the electrochemical stability.

  6. Life cycle considerations for improving sustainability assessments in seafood awareness campaigns.

    Science.gov (United States)

    Pelletier, Nathan; Tyedmers, Peter

    2008-11-01

    It is widely accepted that improving the sustainability of seafood production requires efforts to reverse declines in global fisheries due to overfishing and to reduce the impacts to host ecosystems from fishing and aquaculture production technologies. Reflective of on-going dialogue amongst participants in an international research project applying Life Cycle Assessment to better understand and manage global salmon production systems, we argue here that such efforts must also address the wider range of biophysical, ecological, and socioeconomic impacts stemming from the material and energetic throughput associated with these industries. This is of particular relevance given the interconnectivity of global environmental change, ocean health, and the viability of seafood production in both fisheries and aquaculture. Although the growing popularity of numerous ecolabeling, certification, and consumer education programs may be making headway in influencing Western consumer perceptions of the relative sustainability of alternative seafood products, we also posit that the efficacy of these initiatives in furthering sustainability objectives is compromised by the use of incomplete criteria. An emerging body of Life Cycle Assessment research of fisheries and aquaculture provides valuable insights into the biophysical dimensions of environmental performance in alternative seafood production and consumption systems, and should be used to inform a more holistic approach to labeling, certifying, and educating for sustainability in seafood production. More research, however, must be undertaken to develop novel techniques for incorporating other critical dimensions, in particular, socioeconomic considerations, into our sustainability decision-making.

  7. Improving cardiac myocytes performance by CNTs platforms

    Directory of Open Access Journals (Sweden)

    Valentina eMartinelli

    2013-09-01

    Full Text Available The application of nanotechnology to the cardiovascular system has increasingly caught scientists’ attention as a potentially powerful tool for the development of new generation devices able to interface, repair or boost the performance of cardiac tissue. Carbon nanotubes (CNTs are considered as promising materials for nanomedicine applications in general and have been recently tested towards excitable cell growth. CNTs are cylindrically shaped structures made up of rolled-up graphene sheets, with unique electrical, thermal and mechanical properties, able to effectively conducting electrical current in electrochemical interfaces. CNTs-based scaffolds have been recently found to support the in vitro growth of cardiac cells: in particular, their ability to improve cardiomyocytes proliferation, maturation and electrical behavior are making CNTs extremely attractive for the development and exploitation of interfaces able to impact on cardiac cells physiology and function.

  8. Performance analysis of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    International Nuclear Information System (INIS)

    Modi, Anish; Haglind, Fredrik

    2014-01-01

    Solar thermal power plants have attracted increasing interest in the past few years – with respect to both the design of the various plant components, and extending the operation hours by employing different types of storage systems. One approach to improve the overall plant efficiency is to use direct steam generation with water/steam as both the heat transfer fluid in the solar receivers and the cycle working fluid. This enables operating the plant with higher turbine inlet temperatures. Available literature suggests that it is feasible to use ammonia-water mixtures at high temperatures without corroding the equipment by using suitable additives with the mixture. The purpose of the study reported here was to investigate if there is any benefit of using a Kalina cycle for a direct steam generation, central receiver solar thermal power plant with high live steam temperature (450 °C) and pressure (over 100 bar). Thermodynamic performance of the Kalina cycle in terms of the plant exergy efficiency was evaluated and compared with a simple Rankine cycle. The rates of exergy destruction for the different components in the two cycles were also calculated and compared. The results suggest that the simple Rankine cycle exhibits better performance than the Kalina cycle when the heat input is only from the solar receiver. However, when using a two-tank molten-salt storage system as the primary source of heat input, the Kalina cycle showed an advantage over the simple Rankine cycle because of about 33 % reduction in the storage requirement. The solar receiver showed the highest rate of exergy destruction for both the cycles. The rates of exergy destruction in other components of the cycles were found to be highly dependent on the amount of recuperation, and the ammonia mass fraction and pressure at the turbine inlet. - Highlights: •Kalina cycle for a central receiver solar thermal power plant with direct steam generation. •Rankine cycle shows better plant exergy

  9. The influence of diffusion absorption refrigeration cycle configuration on the performance

    International Nuclear Information System (INIS)

    Zohar, A.; Jelinek, M.; Levy, A.; Borde, I.

    2007-01-01

    Based on a full thermodynamic model for ammonia-water diffusion absorption refrigeration (DAR) cycle with hydrogen as the auxiliary inert gas, the performance of two fundamental configurations of a DAR cycle, with and without condensate sub-cooling prior to the evaporator entrance, were studied and compared. The performances of the two cycles were examined parametrically by computer simulations. Mass and energy conservation equations were developed for each component of the cycles and solved numerically. It was found that the DAR cycle without condensate sub-cooling shows higher COP of 14-20% in compare with the DAR cycle with the condensate sub-cooling, but it occurs at higher evaporator temperature of about 15 deg. C

  10. Thermodynamic performance analysis of sequential Carnot cycles using heat sources with finite heat capacity

    International Nuclear Information System (INIS)

    Park, Hansaem; Kim, Min Soo

    2014-01-01

    The maximum efficiency of a heat engine is able to be estimated by using a Carnot cycle. Even though, in terms of efficiency, the Carnot cycle performs the role of reference very well, its application is limited to the case of infinite heat reservoirs, which is not that realistic. Moreover, considering that one of the recent key issues is to produce maximum work from low temperature and finite heat sources, which are called renewable energy sources, more advanced theoretical cycles, which can present a new standard, and the research about them are necessary. Therefore, in this paper, a sequential Carnot cycle, where multiple Carnot cycles are connected in parallel, is studied. The cycle adopts a finite heat source, which has a certain initial temperature and heat capacity, and an infinite heat sink, which is assumed to be ambient air. Heat transfer processes in the cycle occur with the temperature difference between a heat reservoir and a cycle. In order to resolve the heat transfer rate in those processes, the product of an overall heat transfer coefficient and a heat transfer area is introduced. Using these conditions, the performance of a sequential Carnot cycle is analytically calculated. Furthermore, as the efforts for enhancing the work of the cycle, the optimization research is also conducted with numerical calculation. - Highlights: • Modified sequential Carnot cycles are proposed for evaluating low grade heat sources. • Performance of sequential Carnot cycles is calculated analytically. • Optimization study for the cycle is conducted with numerical solver. • Maximum work from a heat source under a certain condition is obtained by equations

  11. Improving chemistry performance in CANDU plants

    International Nuclear Information System (INIS)

    Turner, C.; Guzonas, D.

    2010-01-01

    system to facilitate improved chemistry control and to help staff to proactively identify and address emerging issues before they result in a loss of performance. This paper will outline AECL's chemistry control philosophy, and provide specific examples to illustrate how changes to plant design, materials, operational procedures, and chemistry specifications are being implemented to support improved chemistry performance in existing and new-build CANDU® plants. (author)

  12. A comparison of improved power plant technologies on lignite with (PFBC) and (IGCC) cycles

    International Nuclear Information System (INIS)

    Cherepnalkovski, Ilija

    1997-01-01

    Technologies and process diagrams descriptions for PFBC (Pressurised Fluidized Bed Combustion) and IGCC (Integrated Gasification Combined Cycle) are presented as for improved cycles with modern clean coal technologies, the most popular currently. A special attention is paid to the possibilities for Macedonian lignites use on the power plants with PFBC and IGCC cycles. The comparison of the above mention technologies has been done particularly on the desulfurization, NO x reduction, ash elimination and its use in the building and construction industries. A comparison between the power plants with PFBC and IGCC cycles is made by the following criteria: cycle efficiency, desulfurization and nitrogen oxides reduction, power plant complexity and their cost, as well as plant reliability. (Author)

  13. Performance estimation of ejector cycles using heavier hydrocarbon refrigerants

    International Nuclear Information System (INIS)

    Kasperski, Jacek; Gil, Bartosz

    2014-01-01

    Computer software basing on theoretical model of Huang et al. with thermodynamic properties of hydrocarbons was prepared. Investigation was focused on nine hydrocarbons: propane, butane, iso-butane, pentane, iso-pentane, hexane, heptane and octane. A series of calculations was carried out for the generator temperature between 70 and 200 °C, with assumed temperatures of evaporation 10 °C and condensation 40 °C. Calculation results show that none of the hydrocarbons enables high efficiency of a cycle in a wide range of temperature. Each hydrocarbon has its own maximal entrainment ratio at its individual temperature of optimum. Temperatures of entrainment ratios optimum increase according to the hydrocarbon heaviness with simultaneous increase of entrainment ratio peak values. Peak values of the COP do not increase according to the hydrocarbons heaviness. The highest COP = 0.32 is achieved for iso-butane at 102 °C and the COP = 0.28 for pentane at 165 °C. Heptane and octane can be ignored. - Highlights: • Advantages of use of higher hydrocarbons as ejector refrigerants were presumed. • Computer software basing on theoretical model of Huang et al. (1999) was prepared. • Optimal temperature range of vapor generation for each hydrocarbon was calculated

  14. Performance improvement of optical semiconductor sources

    International Nuclear Information System (INIS)

    El Tokhy, M.E.M.E

    2009-01-01

    This thesis has been concerned with a detailed study of nano-technology quantum sources. From these sources, quantum cascaded laser (QCLs) and quantum dot lasers (QDs), are studied theoretically. Block diagram models based on VisSim environment in junction with mathematical models are developed to analyze these kinds of optical sources. The mathematical model is derived to express explicitly the performance of the device, while a block diagram model is implemented which implicitly describe the same device. By using these mathematical models, new expressions are obtained. Accurate and efficient modeling of these sources is being increasingly important in the design and optimization of optical integrated circuits and circuit component. In the case of QCLs, the diagram is used to calculate its characteristics such as potential voltage, output optical power, current, threshold current density, slope efficiency, differential efficiency, and optical gain of these devices. Furthermore, the effect of each parameter of the QCLs, such as number of periods; N p , operating temperature; T, waveguide losses; α w , mirror losses; α m , on its performance are discussed in details. To demonstrate these effects further, the changes in three dimensional are plotted. In another mean, improving the lasing properties of the QCLs through both block diagram and mathematical models is the main scope in this thesis. In order to enhance the performance of the underlined device, mathematical model parameters are tuned to obtain the optimum behavior. Additionally, it is important to model and analyze the effects of these physical parameters on the performance of QCLs. These parameters play the central role in specifying the optical characteristics of the considered laser source. Proposed relation that linked emitted power with QCLs parameters is deduced. Moreover, it is important to have a large amount of radiated power, where increasing the amount of radiated power represents the main

  15. Improving Fuel Cycle Design and Safety Characteristics of a Gas Cooled Fast Reactor

    International Nuclear Information System (INIS)

    Rooijen, W.F.G. van

    2006-01-01

    gradients within the fuel assemblies would be too high, and fuel economy is poor. Two improved fuel concepts are proposed: (1) a redesign of the classic TRISO coated particle fuel, and (2) an innovative hollow sphere design. Both fuel elements are used in a core design based on direct cooling of the coated particle fuel. To increase the neutronic margins and obtain adequate self-breeding capabilities, the proposed reactor has 2400 MWth power output and a power density of 50 MW/m 3 . With both types of fuel, it is possible to obtain a closed fuel cycle. Long irradiation intervals (several years) are possible with a low burnup reactivity swing, which reduces the required over-reactivity of the fresh core and reduces control rod requirements during operation. In the closed fuel cycle it is important to be able to predict whether a certain initial fuel composition will in fact yield a new fuel, after irradiation, cool down and reprocessing, with which the reactor can be restarted. A theoretical framework is presented in this thesis which allows calculation of the ‘Breeding Gain’ (BG) of the reactor. The BG quantifies the performance of the fuel for batch i + 1 as a function of the composition of the initial fuel of batch i. If this BG can be made equal to zero, both fuel compositions give the same nuclear performance. To be able to calculate the fuel performance, the reactivity weight, i.e. the contribution of each isotope to the overall reactivity of the reactor, needs to be estimated. It is proposed in this thesis to calculate these reactivity weights using a first-order eigenvalue perturbation calculation. It is shown that this approach yields an expression which reduces to a well-established formula for reactivity weights. All steps in the fuel cycle, i.e. irradiation, cool down and reprocessing, have to be taken into account to calculate the Breeding Gain for the closed fuel cycle. First order nuclide perturbation theory provides an efficient method to calculate the

  16. An interface-reconstruction effect for rechargeable aluminum battery in ionic liquid electrolyte to enhance cycling performances

    Directory of Open Access Journals (Sweden)

    Feng Wu

    2018-01-01

    Full Text Available Aluminum (Al metal has been regarded as a promising anode for rechargeable batteries because of its natural abundance and high theoretical specific capacity. However, rechargeable aluminum batteries (RABs using Al metal as anode display poor cycling performances owing to interface problems between anode and electrolyte. The solid-electrolyte interphase (SEI layer on the anode has been confirmed to be essential for improving cycling performances of rechargeable batteries. Therefore, we immerse the Al metal in ionic liquid electrolyte for some time before it is used as anode to remove the passive film and expose fresh Al to the electrolyte. Then the reactions of exposed Al, acid, oxygen and water in electrolyte are occurred to form an SEI layer in the cycle. Al/electrolyte/V2O5 full batteries with the thin, uniform and stable SEI layer on Al metal anode perform high discharge capacity and coulombic efficiency (CE. This work illustrates that an SEI layer is formed on Al metal anode in the cycle using a simple and effective pretreatment process and results in superior cycling performances for RABs.

  17. Using Iterative Plan-Do-Study-Act Cycles to Improve Teaching Pedagogy.

    Science.gov (United States)

    Murray, Elizabeth J

    2018-01-15

    Most students entering nursing programs today are members of Generation Y or the Millennial generation, and they learn differently than previous generations. Nurse educators must consider implementing innovative teaching strategies that appeal to the newest generation of learners. The Plan-Do-Study-Act cycle is a framework that can be helpful when planning, assessing, and continually improving teaching pedagogy. This article describes the use of iterative Plan-Do-Study-Act cycles to implement a change in teaching pedagogy.

  18. Design and optimization of a novel organic Rankine cycle with improved boiling process

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Larsen, U.; Knudsen, Thomas

    2015-01-01

    to improve the boiling process. Optimizations are carried out for eight hydrocarbon mixtures for hot fluid inlet temperatures at 120 °C and 90 °C, using a genetic algorithm to determine the cycle conditions for which the net power output is maximized. The most promising mixture is an isobutane....../pentane mixture which, for the 90 °C hot fluid inlet temperature case, achieves a 14.5% higher net power output than an optimized organic Rankine cycle using the same mixture. Two parameter studies suggest that optimum conditions for the organic split-cycle are when the temperature profile allows the minimum...

  19. Reflector Performance Study in Ultra-long Cycle Fast Reactor

    International Nuclear Information System (INIS)

    Tak, Taewoo; Kong, Chidong; Choe, Jiwon; Lee, Deokjung

    2013-01-01

    There are reflector assemblies outside the fuel region, surrounding the fuel assemblies and axial reflector is located at the bottom of the core to control the neutron leakage fraction which is an important factor in fast reactor system. HT-9 was used as a reflector material as well as a structure material. In this study, alternative reflector materials were proposed and their reflection performance was tested and studied focused on its physics. ODS-MA957 and SiC were chosen from iron based alloy and ceramic respectively. The two materials were tested and compared with HT-9 in UCFR-1000 as a radial and an axial reflector and it was evaluated from the neutronics point of view with comparing the core life and the coolant void reactivity. The calculation and evaluation were performed by McCARD Monte Carlo code. The reflector materials for UCFR-1000 have been investigated in the aspect of neutronics. The reflection effect shows different performance corresponding to reflector material used. Also, the neutron energy spectrum is affected by changing materials which causes spectrum softening but it is not enough to influence the core life. With more reflector material candidates such as lead-based liquid metal, reflection performance and core parameter study will be investigated for next step

  20. Exergoeconomic performance optimization for a steady-flow endoreversible refrigeration model including six typical cycles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lingen; Kan, Xuxian; Sun, Fengrui; Wu, Feng [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

    2013-07-01

    The operation of a universal steady flow endoreversible refrigeration cycle model consisting of a constant thermal-capacity heating branch, two constant thermal-capacity cooling branches and two adiabatic branches is viewed as a production process with exergy as its output. The finite time exergoeconomic performance optimization of the refrigeration cycle is investigated by taking profit rate optimization criterion as the objective. The relations between the profit rate and the temperature ratio of working fluid, between the COP (coefficient of performance) and the temperature ratio of working fluid, as well as the optimal relation between profit rate and the COP of the cycle are derived. The focus of this paper is to search the compromised optimization between economics (profit rate) and the utilization factor (COP) for endoreversible refrigeration cycles, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. Moreover, performance analysis and optimization of the model are carried out in order to investigate the effect of cycle process on the performance of the cycles using numerical example. The results obtained herein include the performance characteristics of endoreversible Carnot, Diesel, Otto, Atkinson, Dual and Brayton refrigeration cycles.

  1. Performance estimates for the Space Station power system Brayton Cycle compressor and turbine

    Science.gov (United States)

    Cummings, Robert L.

    1989-01-01

    The methods which have been used by the NASA Lewis Research Center for predicting Brayton Cycle compressor and turbine performance for different gases and flow rates are described. These methods were developed by NASA Lewis during the early days of Brayton cycle component development and they can now be applied to the task of predicting the performance of the Closed Brayton Cycle (CBC) Space Station Freedom power system. Computer programs are given for performing these calculations and data from previous NASA Lewis Brayton Compressor and Turbine tests is used to make accurate estimates of the compressor and turbine performance for the CBC power system. Results of these calculations are also given. In general, calculations confirm that the CBC Brayton Cycle contractor has made realistic compressor and turbine performance estimates.

  2. Nanotechnological inventions considerably improve performance characteristics

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2014-06-01

    Full Text Available The invention «The method of production of carbon nanomaterial (RU 2509053» can be used as an additive for concretes and polymers which significantly improves their performance characteristics. The method of production of carbon nanomaterial consists of the following stages: preliminary preparation of sphagnous moss when it is refined from foreign admixtures, dried up to 10% humidity and ground, then ground material is exposed to pyrolysis under the temperature 850–950оC for 1–2 hours and cooled up to the environment temperature. After that amorphous carbon obtained in pyrolysis is treated with mechanical activation in the variable planetary mill for 7–10 hours. The invention makes it possible to provide increased outcome of nanotubes with high cleanliness. The invention «The method of production of nanodispersed metal powders and alloys of them (RU 2509626» relates to the powder metallurgy. Powder metal chloride or powder mixture at least of two metal chlorides is treated in the environment of the water steam which is supplied in reaction space at the rate of 50–100 ml/min at the temperature 400–800оC at the presence of absorbent carbon or introducing carbon oxide (II obtained during dissolution of formic acid HCOOH. The invention provides reliable production of nanodispersed metal powders and alloys of them from 3-d metal range: Ni, Co, Cu, Fe, Zn which can be used in powder metallurgy to improve baking process, in chemical industry as the fillers of polymers and reaction catalysts; as additives to anticorrosive covers, etc.

  3. The EXPLORER gravitational wave antenna: recent improvements and performances

    CERN Document Server

    Astone, P; Bonifazi, P; Carelli, P; Castellano, M G; Cavallari, G; Coccia, E; Cosmelli, C; D'Antonio, S; Fafone, V; Federici, G; Minenkov, Y; Modestino, G; Modena, I; Moleti, A; Pizzella, G; Pallottino, G V; Quintieri, L; Rocchi, A; Ronga, F; Terenzi, R; Torrioli, G; Visco, M

    2002-01-01

    Since the beginning of 2000 the EXPLORER gravity wave (GW) detector has been operated continuously after a stop devoted to improve the apparatus. The antenna has been equipped with a new read-out. The use of a new transducer, characterized by a very small gap, and a dc-SQUID with a high coupling, led to a better sensitivity and a larger bandwidth. The EXPLORER sensitivity in terms of spectral noise amplitude, at present (June 2001), is 10 sup - sup 2 sup 0 Hz sup - sup 1 sup / sup 2 over a bandwidth of 35 Hz and 3 x 10 sup - sup 2 sup 1 Hz sup - sup 1 sup / sup 2 with a bandwidth of about 6 Hz, corresponding to a sensitivity to short conventional GW bursts of h = 4 x 10 sup - sup 1 sup 9. The performance is stable and the apparatus is taking data with a duty cycle in excess of 80%.

  4. The EXPLORER gravitational wave antenna: recent improvements and performances

    International Nuclear Information System (INIS)

    Astone, P; Bassan, M; Bonifazi, P; Carelli, P; Castellano, M G; Cavallari, G; Coccia, E; Cosmelli, C; D'Antonio, S; Fafone, V; Federici, G; Minenkov, Y; Modestino, G; Modena, I; Moleti, A; Pizzella, G; Pallottino, G V; Quintieri, L; Rocchi, A; Ronga, F; Terenzi, R; Torrioli, G; Visco, M

    2002-01-01

    Since the beginning of 2000 the EXPLORER gravity wave (GW) detector has been operated continuously after a stop devoted to improve the apparatus. The antenna has been equipped with a new read-out. The use of a new transducer, characterized by a very small gap, and a dc-SQUID with a high coupling, led to a better sensitivity and a larger bandwidth. The EXPLORER sensitivity in terms of spectral noise amplitude, at present (June 2001), is 10 -20 Hz -1/2 over a bandwidth of 35 Hz and 3 x 10 -21 Hz -1/2 with a bandwidth of about 6 Hz, corresponding to a sensitivity to short conventional GW bursts of h = 4 x 10 -19 . The performance is stable and the apparatus is taking data with a duty cycle in excess of 80%

  5. Spatial Modulation Improves Performance in CTIS

    Science.gov (United States)

    Bearman, Gregory H.; Wilson, Daniel W.; Johnson, William R.

    2009-01-01

    Suitably formulated spatial modulation of a scene imaged by a computed-tomography imaging spectrometer (CTIS) has been found to be useful as a means of improving the imaging performance of the CTIS. As used here, "spatial modulation" signifies the imposition of additional, artificial structure on a scene from within the CTIS optics. The basic principles of a CTIS were described in "Improvements in Computed- Tomography Imaging Spectrometry" (NPO-20561) NASA Tech Briefs, Vol. 24, No. 12 (December 2000), page 38 and "All-Reflective Computed-Tomography Imaging Spectrometers" (NPO-20836), NASA Tech Briefs, Vol. 26, No. 11 (November 2002), page 7a. To recapitulate: A CTIS offers capabilities for imaging a scene with spatial, spectral, and temporal resolution. The spectral disperser in a CTIS is a two-dimensional diffraction grating. It is positioned between two relay lenses (or on one of two relay mirrors) in a video imaging system. If the disperser were removed, the system would produce ordinary images of the scene in its field of view. In the presence of the grating, the image on the focal plane of the system contains both spectral and spatial information because the multiple diffraction orders of the grating give rise to multiple, spectrally dispersed images of the scene. By use of algorithms adapted from computed tomography, the image on the focal plane can be processed into an image cube a three-dimensional collection of data on the image intensity as a function of the two spatial dimensions (x and y) in the scene and of wavelength (lambda). Thus, both spectrally and spatially resolved information on the scene at a given instant of time can be obtained, without scanning, from a single snapshot; this is what makes the CTIS such a potentially powerful tool for spatially, spectrally, and temporally resolved imaging. A CTIS performs poorly in imaging some types of scenes in particular, scenes that contain little spatial or spectral variation. The computed spectra of

  6. Clinical performance improvement series. Classic CQI integrated with comprehensive disease management as a model for performance improvement.

    Science.gov (United States)

    Joshi, M S; Bernard, D B

    1999-08-01

    challenge is to provide leadership support, to reward and recognize best practice performers, and to emphasize the use of data for feedback and improvement. As these processes are implemented successfully, and evidence of improved outcomes is documented, it is likely that this approach will be more widely embraced and that organizationwide performance improvement will increase significantly. Health care has traditionally invested extraordinary resources in developing best practice approaches, including guidelines, education programs, or other tangible products and services. Comparatively little time, effort, and resources have been targeted to implementation and use, the stage at which most efforts fail. CQI's emphasis on data, rapid diffusion of innovative programs, and rapid cycle improvements enhance the implementation and effectiveness of disease management.

  7. Performance estimation of Tesla turbine applied in small scale Organic Rankine Cycle (ORC) system

    International Nuclear Information System (INIS)

    Song, Jian; Gu, Chun-wei; Li, Xue-song

    2017-01-01

    Highlights: • One-dimensional model of the Tesla turbine is improved and applied in ORC system. • Working fluid properties and system operating conditions impact efficiency. • The influence of turbine efficiency on ORC system performance is evaluated. • Potential of using Tesla turbine in ORC systems is estimated. - Abstract: Organic Rankine Cycle (ORC) system has been proven to be an effective method for the low grade energy utilization. In small scale applications, the Tesla turbine offers an attractive option for the organic expander if an efficient design can be achieved. The Tesla turbine is simple in structure and is easy to be manufactured. This paper improves the one-dimensional model for the Tesla turbine, which adopts a non-dimensional formulation that identifies the dimensionless parameters that dictates the performance features of the turbine. The model is used to predict the efficiency of a Tesla turbine that is applied in a small scale ORC system. The influence of the working fluid properties and the operating conditions on the turbine performance is evaluated. Thermodynamic analysis of the ORC system with different organic working fluids and under various operating conditions is conducted. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, the Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.

  8. Learning to improve path planning performance

    International Nuclear Information System (INIS)

    Chen, Pang C.

    1995-04-01

    In robotics, path planning refers to finding a short. collision-free path from an initial robot configuration to a desired configuratioin. It has to be fast to support real-time task-level robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To remedy this situation, we present and analyze a learning algorithm that uses past experience to increase future performance. The algorithm relies on an existing path planner to provide solutions to difficult tasks. From these solutions, an evolving sparse network of useful robot configurations is learned to support faster planning. More generally, the algorithm provides a speedup-learning framework in which a slow but capable planner may be improved both cost-wise and capability-wise by a faster but less capable planner coupled with experience. The basic algorithm is suitable for stationary environments, and can be extended to accommodate changing environments with on-demand experience repair and object-attached experience abstraction. To analyze the algorithm, we characterize the situations in which the adaptive planner is useful, provide quantitative bounds to predict its behavior, and confirm our theoretical results with experiments in path planning of manipulators. Our algorithm and analysis are sufficiently, general that they may also be applied to other planning domains in which experience is useful

  9. EDUCATIONAL POLICIES AND INITIATIVES FOR IMPROVED PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Flavia, CAIA

    2015-03-01

    Full Text Available According to Gartner estimates, due to increased variety, speed and data volume, by 2015 there will be a global demand of 4.4 million professionals for real-time analysis of data from sources with different structures, but only one third of the demand will be met. The purpose of this research is to identify possible solutions for improved academic results in the IT domain, considering the time management policies, the content and the student motivations, as well as the business strategy tendencies. These proposals are targeted toward meeting the IT specialists demand. The research is composed of two parts: the first explores the Romanian IT labour market characteristics, while the second investigates the academic education policies that can help mitigate deficiencies and attain higher performance. The deficiencies are identified through a series of statistical research and analysis based on national level databases, adopting a quantitative approach. The policies proposed are supported by a flow model developed considering the students' activity, motivation, traits and results, measured and analysed quantitatively.

  10. Improved Bevatron local injector ion source performance

    International Nuclear Information System (INIS)

    Stover, G.; Zajec, E.

    1985-05-01

    Performance tests of the improved Bevatron Local Injector PIG Ion Source using particles of Si 4 + , Ne 3 + , and He 2 + are described. Initial measurements of the 8.4 keV/nucleon Si 4 + beam show an intensity of 100 particle microamperes with a normalized emittance of .06 π cm-mrad. A low energy beam transport line provides mass analysis, diagnostics, and matching into a 200 MHz RFQ linac. The RFQ accelerates the beam from 8.4 to 200 keV/nucleon. The injector is unusual in the sense that all ion source power supplies, the ac distribution network, vacuum control equipment, and computer control system are contained in a four bay rack mounted on insulators which is located on a floor immediately above the ion source. The rack, transmission line, and the ion source housing are raised by a dc power supply to 80 kilovolts above earth ground. All power supplies, which are referenced to rack ground, are modular in construction and easily removable for maintenance. AC power is delivered to the rack via a 21 kVA, 3-phase transformer. 2 refs., 5 figs., 1 tab

  11. Effects of hysteresis and Brayton cycle constraints on magnetocaloric refrigerant performance

    Science.gov (United States)

    Brown, T. D.; Buffington, T.; Shamberger, P. J.

    2018-05-01

    Despite promising proofs of concept, system-level implementation of magnetic refrigeration has been critically limited by history-dependent refrigerant losses that interact with governing thermodynamic cycles to adversely impact refrigeration performance. Future development demands a more detailed understanding of how hysteresis limits performance, and of how different types of cycles can mitigate these limitations, but without the extreme cost of experimental realization. Here, the utility of Brayton cycles for magnetic refrigeration is investigated via direct simulation, using a combined thermodynamic-hysteresis modeling framework to compute the path-dependent magnetization and entropy of a model alloy for a variety of feasible Brayton cycles between 0-1.5 T and 0-5 T. By simultaneously varying the model alloy's hysteresis properties and applying extensions of the thermodynamic laws to non-equilibrium systems, heat transfers and efficiencies are quantified throughout the space of hystereses and Brayton cycles and then compared with a previous investigation using Ericsson cycles. It is found that (1) hysteresis losses remain a critical obstacle to magnetic refrigeration implementation, with efficiencies >80% in the model system requiring hysteresis refrigerant transformation temperatures at the relevant fields; (3) for a given hysteresis and field constraint, Brayton and Ericsson-type cycles generate similar efficiencies; for a given temperature span, Ericsson cycles lift more heat per cycle, with the difference decreasing with the refrigerant heat capacity outside the phase transformation region.

  12. Use of polyethylene glycol for the improvement of the cycling stability of bischofite as thermal energy storage material

    International Nuclear Information System (INIS)

    Gutierrez, Andrea; Ushak, Svetlana; Galleguillos, Hector; Fernandez, Angel; Cabeza, Luisa F.; Grágeda, Mario

    2015-01-01

    Highlights: • Bischofite as phase change material for TES is studied. • Thermophysical properties of bischofite mixtures with PEG were determined. • The aim was to improve the cycling stability of bischofite. • The heating and cooling during 30 cycles were measured. • The most stable sample was bischofite + 5% PEG 2 000. - Abstract: Bischofite is a by-product of the non-metallic mining industry. It has been evaluated as phase change material in thermal energy storage, but it shows little cycling stability, therefore in this paper the mixture of bischofite with an additive was studied. Since polyethylene glycol (PEG) is a PCM itself, in this paper PEG (with different molecular weights) is used as additive in a PCM (bischofite) to improve its thermal behaviour. Results show that adding 5% PEG 2 000 to bischofite gives a more cycling stable PCM without affecting its melting temperature neither decreasing significantly its heat of fusion. This research shows that mixing an inorganic PCM with an organic additive can be a good option to improve the thermal performance of the PCM

  13. Improving Mobility Performance in Wheelchair Basketball

    NARCIS (Netherlands)

    Veeger, Thom T.J.; De Witte, Annemarie M H; Berger, Monique A M; van der Slikke, Rienk M A; Veeger, Dirkjan H E J; Hoozemans, Marco J M

    2017-01-01

    OBJECTIVE: This study aimed to investigate which characteristics of athlete, wheelchair and athlete-wheelchair interface are the best predictors of wheelchair basketball mobility performance. DESIGN: Sixty experienced wheelchair basketball players performed a wheelchair mobility performance test to

  14. Behavioral Health and Performance (BHP) Work-Rest Cycles

    Science.gov (United States)

    Leveton, Lauren B.; Whitmire, Alexandra

    2011-01-01

    BHP Program Element Goal: Identify, characterize, and prevent or reduce behavioral health and performance risks associated with space travel, exploration and return to terrestrial life. BHP Requirements: a) Characterize and assess risks (e.g., likelihood and consequences). b) Develop tools and technologies to prevent, monitor, and treat adverse outcomes. c) Inform standards. d) Develop technologies to: 1) reduce risks and human systems resource requirements (e.g., crew time, mass, volume, power) and 2) ensure effective human-system integration across exploration mission.

  15. Improved cycling performance of Li{sub 2}MoO{sub 4}-inlaid LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} cathode materials for lithium-ion battery under high cutoff voltage

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Manfang; Hu, Guorong; Liang, Longwei; Peng, Zhongdong; Du, Ke; Cao, Yanbing, E-mail: cybcsu@csu.edu.cn

    2016-07-15

    Uniform spherical xLi{sub 2}MoO{sub 4}-inlaid LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} materials were successfully prepared through a solid state synthesis. To investigate the material characterization and electrochemical performance after Li{sub 2}MoO{sub 4} modification, X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) mapping, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests were applied. The results of the XRD, Rietveld refinement, SEM and EDS analyses showed that a Mo atom may be incorporated into the crystal lattice of the layer structure. Moreover, the presence of Li{sub 2}MoO{sub 4} on the LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} surface was observed. The thickness of the Li{sub 2}MoO{sub 4} coating layer on the xLi{sub 2}MoO{sub 4}-inlaid LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} material (x = 0.02) was approximately 25 nm. Similarly, XPS was performed to determine the effect of Li{sub 2}MoO{sub 4} modification, confirming the presence of Li{sub 2}MoO{sub 4}. The xLi{sub 2}MoO{sub 4}-inlaid (x = 0.02) LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} materials exhibited a retention capacity 83.5% higher than that of the bare material (40.9%) after 200 cycles at 0.5 C between 3.0 and 4.4 V, and it also exhibited the best electrochemical properties at a cutoff voltage of 4.5 V. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed that the modification of Li{sub 2}MoO{sub 4} plays an important role in improving the electrochemical performance of pristine LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2}. - Highlights: • Electrochemical performance of LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} is improved by Li{sub 2}MoO{sub 4} modification. • Li{sub 2}MoO{sub 4} modification can make the structure of the bare material stable. • Li{sub 2}MoO{sub 4}-inlaid Li[Ni{sub 0.5}Co{sub 0.2}Mn{sub 0.3}]O{sub 2

  16. Improved circadian sleep-wake cycle in infants fed a day/night dissociated formula milk.

    Science.gov (United States)

    Cubero, J; Narciso, D; Aparicio, S; Garau, C; Valero, V; Rivero, M; Esteban, S; Rial, R; Rodríguez, A B; Barriga, C

    2006-06-01

    On the basis of the circadian nutritional variations present in breast milk, and of the implications for the sleep/wake cycle of the nutrients present in infant formula milks, we designed a formula milk nutritionally dissociated into a Day/Night composition. The goal was to improve the bottle-fed infant's sleep/wake circadian rhythm. A total of 21 infants aged 4-20 weeks with sleeping difficulties were enrolled in the three-week duration study. The sleep analysis was performed using an actimeter (Actiwatch) placed on an ankle of each infant to uninterruptedly record movements during the three weeks. The dissociated Day milk, designed to be administered from 06:00 to 18:00, contained low levels of tryptophan (1.5g/100g protein) and carbohydrates, high levels of proteins, and the nucleotides Cytidine 5 monophosphate, Guanosine 5 monophosphate and Inosine 5 monophosphate. The dissociated Night milk, designed to be administered from 18.00 to 06.00, contained high levels of tryptophan (3.4g/100g protein) and carbohydrates, low levels of protein, and the nucleotides Adenosine 5 monophosphate and Uridine 5 monophosphate. Three different milk-feeding experiments were performed in a double-blind procedure covering three weeks. In week 1 (control), the infants received both by day and by night a standard formula milk; in week 2 (inverse control), they received the dissociated milk inversely (Night/Day instead of Day/Night); and in week 3, they received the Day/Night dissociated formula concordant with the formula design. When the infants were receiving the Day/Night dissociated milk in concordance with their environment, they showed improvement in all the nocturnal sleep parameters analyzed: total hours of sleep, sleep efficiency, minutes of nocturnal immobility, nocturnal awakenings, and sleep latency. In conclusion, the use of a chronobiologically adjusted infant formula milk seems to be effective in improving the consolidation of the circadian sleep/wake cycle in bottle

  17. Fuel conversion efficiency improvements in a highly boosted spark-ignition engine with ultra-expansion cycle

    International Nuclear Information System (INIS)

    Li, Tie; Zheng, Bin; Yin, Tao

    2015-01-01

    Highlights: • Ultra-expansion cycle SI engine is investigated. • An improvement of 9–26% in BSFC at most frequently operated conditions is obtained. • At high and medium loads, BSFC improvement is attributed to the increased combustion efficiency and reduced exhaust energy. • At low loads, reduction in pumping loss and exhaust energy is the primary contributors to BSFC improvement. • Technical challenge in practical application of this type of engine is discussed. - Abstract: A four-cylinder, intake boosted, port fuel injection (PFI), spark-ignition (SI) engine is modified to a three-cylinder engine with the outer two cylinders working in the conventional four stroke cycle and with the inner cylinder working only with the expansion and exhausting strokes. After calibration and validation of the engine cycle simulation models using the experimental data in the original engine, the performance of the three-cylinder engine with the ultra-expansion cycle is numerically studied. Compared to the original engine, the fuel consumptions under the most-frequently operated conditions are improved by 9–26% and the low fuel consumption area on the operating map are drastically enlarged for the ultra-expansion cycle engine with the proper design. Nonetheless, a higher intake boosting is needed for the ultra-expansion cycle engine to circumvent the significant drop in the wide-open-throttle (WOT) performance, and compression ratio of the combustion cylinder must be reduced to avoid knocking combustion. Despite of the reduced compression ratio, however, the total expansion ratio is increased to 13.8 with the extra expansion of the working gas in the inner cylinder. Compared to the conventional engine, the theoretical thermal efficiency is therefore increased by up to above 4.0% with the ultra-expansion cycle over the most load range. The energy balance analysis shows that the increased combustion efficiency, reduced exhaust energy and the extra expansion work in the

  18. Improvement of characteristic statistic algorithm and its application on equilibrium cycle reloading optimization

    International Nuclear Information System (INIS)

    Hu, Y.; Liu, Z.; Shi, X.; Wang, B.

    2006-01-01

    A brief introduction of characteristic statistic algorithm (CSA) is given in the paper, which is a new global optimization algorithm to solve the problem of PWR in-core fuel management optimization. CSA is modified by the adoption of back propagation neural network and fast local adjustment. Then the modified CSA is applied to PWR Equilibrium Cycle Reloading Optimization, and the corresponding optimization code of CSA-DYW is developed. CSA-DYW is used to optimize the equilibrium cycle of 18 month reloading of Daya bay nuclear plant Unit 1 reactor. The results show that CSA-DYW has high efficiency and good global performance on PWR Equilibrium Cycle Reloading Optimization. (authors)

  19. ESBWR enhanced flow distribution with optimized orificing and related fuel cycle performance

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, G. J.; Karve, A. A.; Fawcett, R. M. [Global Nuclear Fuel - America, 3901 Castle Hayne Road, Wilmington, NC 28401 (United States)

    2012-07-01

    The Economic Simplified Boiling Water Reactor (ESBWR) is GEH's latest Generation III+ reactor design with natural circulation coolant flow and passive safety features. Reliance on natural circulation as the sole means of core coolant driving force results in increased power-to-flow ratio and places increased importance on the efficient distribution of core flow in order to achieve optimum thermal margins and improved fuel cycle efficiency. In addition, the large core size of the ESBWR, containing 1132 bundles, greatly benefits from a more targeted distribution of flow, directing a higher fraction of flow to high power bundles in the 'ring of fire' region of typical BWR loading patterns and a lower fraction of flow to low power bundles on and near the core periphery. Desirable flow distributions can be achieved by modifying the hydraulic resistance of the inlet orifices to preferentially force flow to the targeted region. The inlet orifice is a feature that is incorporated into the fuel support piece of a typical BWR design. The majority of existing forced circulation BWR's rely on only two orifice types - a peripheral orifice located along the outermost row and a central orifice in all other locations. A more optimum distribution of core flow is achievable with the introduction of multiple inlet orifice types. Multi-zone orifice layouts comprised of two, three and four types have been evaluated for the ESBWR. An efficient radial distribution of flow can have a direct beneficial effect on the Minimum Critical Power Ratio (MCPR). An improved multi-zone orifice layout in the ESBWR has the potential of significantly increasing active flow in high power bundles. On average, this flow increase corresponds to a noteworthy MCPR improvement. Additional MCPR margin may be used to enhance operating flexibility and to achieve reduced fuel cycle costs over the plant lifetime. Combined with GNF's latest high performance fuel design for the ESBWR, GNF2E

  20. The public health nutrition intervention management bi-cycle: a model for training and practice improvement.

    Science.gov (United States)

    Hughes, Roger; Margetts, Barrie

    2012-11-01

    The present paper describes a model for public health nutrition practice designed to facilitate practice improvement and provide a step-wise approach to assist with workforce development. The bi-cycle model for public health nutrition practice has been developed based on existing cyclical models for intervention management but modified to integrate discrete capacity-building practices. Education and practice settings. This model will have applications for educators and practitioners. Modifications to existing models have been informed by the authors' observations and experiences as practitioners and educators, and reflect a conceptual framework with applications in workforce development and practice improvement. From a workforce development and educational perspective, the model is designed to reflect adult learning principles, exposing students to experiential, problem-solving and practical learning experiences that reflect the realities of work as a public health nutritionist. In doing so, it assists the development of competency beyond knowing to knowing how, showing how and doing. This progression of learning from knowledge to performance is critical to effective competency development for effective practice. Public health nutrition practice is dynamic and varied, and models need to be adaptable and applicable to practice context to have utility. The paper serves to stimulate debate in the public health nutrition community, to encourage critical feedback about the validity, applicability and utility of this model in different practice contexts.

  1. Optimization of the performance characteristics in an irreversible magnetic Brayton refrigeration cycle

    International Nuclear Information System (INIS)

    Wang Hao; Liu Sanqiu

    2008-01-01

    An irreversible cycle model of magnetic Brayton refrigerators is established, in which the thermal resistance and irreversibility in the two adiabatic processes are taken into account. Expressions for several important performance parameters, such as the coefficient of performance, cooling rate and power input are derived. Moreover, the optimal performance parameters are obtained at the maximum coefficient of performance. The optimization region (or criteria) for an irreversible magnetic Brayton refrigerator is obtained. The results obtained here have general significance and will be helpful to understand deeply the performance of a magnetic Brayton refrigeration cycle

  2. Thermal performance of shallow solar pond under open cycle continuous flow heating mode for heat extraction

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt)]. E-mail: aasebaii@yahoo.com; Aboul-Enein, S. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt); Ramadan, M.R.I. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt); Khallaf, A.M. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt)

    2006-05-15

    The thermal performance of a shallow solar pond (SSP) under an open cycle continuous flow heating mode for heat extraction has been investigated. A serpentine heat exchanger (HE), either welded to the absorber plate or immersed in the pond water, has been used for extracting the heat. Suitable computer programs have been developed based on analytical solutions of the energy balance equations for the various elements of the SSP in the presence of the HE. Numerical calculations have been performed to study the effect of different operational and configurational parameters on the pond performance. In order to improve the pond performance, optimization of the various dimensions of the pond with the HE has been performed. The effects of the design parameters of the HE's tube, i.e. length L{sub he}, diameter D and mass flow rate m-bar {sub f} of the fluid flowing through the HE, on the pond performance have been investigated. The outlet temperature of the HE's fluid T{sub fo} is found to increase with increase of the HE length L{sub he}, and it decreases with increase of the mass flow rate of the HE's fluid m-bar {sub f} up to typical values for these parameters. Typical values for L{sub he} and m-bar {sub f} are found to be 4m and 0.004kg/s beyond which the change in T{sub fo} becomes insignificant. Experiments have been performed for the pond under different operational conditions with a HE welded to the absorber plate. To validate the proposed mathematical models, comparisons between experimental and theoretical results have been performed. Good agreement has been achieved.

  3. Using business intelligence to improve performance.

    Science.gov (United States)

    Wadsworth, Tom; Graves, Brian; Glass, Steve; Harrison, A Marc; Donovan, Chris; Proctor, Andrew

    2009-10-01

    Cleveland Clinic's enterprise performance management program offers proof that comparisons of actual performance against strategic objectives can enable healthcare organization to achieve rapid organizational change. Here are four lessons Cleveland Clinic learned from this initiative: Align performance metrics with strategic initiatives. Structure dashboards for the CEO. Link performance to annual reviews. Customize dashboard views to the specific user.

  4. Continuous improvement of the MHTGR safety and competitive performance

    International Nuclear Information System (INIS)

    Eichenberg, T.W.; Etzel, K.T.; Mascaro, L.L.; Rucker, R.A.

    1992-05-01

    An increase in reactor module power from 350 to 450 MW(t) would markedly improve the economics of the Modular High Temperature Gas-Cooled Reactor (MHTGR). The higher power level was recommended as the result of an in-depth cost reduction study undertaken to compete with the declining price of fossil fuel. The safety assessment confirms that the high level of safety, which relies on inherent characteristics and passive features, is maintained at the elevated power level. Preliminary systems, nuclear, and safety performance results are discussed for the recommended 450 MW(t) design. Optimization of plant parameters and design modifications accommodated the operation of the steam generator and circulator at the higher power level. Events in which forced cooling is lost, designated as conduction cooldowns are described in detail. For the depressurized conduction cooldown, without full helium inventory, peak fuel temperatures are significantly lowered. A more negative temperature coefficient of reactivity was achieved while maintaining an adequate fuel cycle and reactivity control. Continual improvement of the MHTGR delivers competitive performance without relinquishing the high safety margins demanded of the next generation of power plants

  5. Optimization analysis of the performance of an irreversible Ericsson refrigeration cycle in the micro/nanoscale

    International Nuclear Information System (INIS)

    Wang Hao; Wu Guoxing; Fu Yueming

    2011-01-01

    A general micro/nanoscaled model of the Ericsson refrigeration cycle is established in which finite-rate heat transfer, heat leak and regeneration time are taken into account. Based on the model, expressions for several important parameters such as the coefficient of performance (COP), cooling rate and power input are derived. By using numerical calculation and illustration, the influence of 'thermosize effects' on the performance of the Ericsson refrigeration cycle is discussed and evaluated. The optimal ranges of the COP, cooling rate and power input are determined. Furthermore, some special cases are discussed in detail. The results obtained here will provide theoretical guidance on designing a micro/nanoscaled Ericsson cycle device.

  6. NASA Contributions to Improve Understanding of Extreme Events in the Global Energy and Water Cycle

    Science.gov (United States)

    Lapenta, William M.

    2008-01-01

    The U.S. Climate Change Science Program (CCSP) has established the water cycle goals of the Nation's climate change program. Accomplishing these goals will require, in part, an accurate accounting of the key reservoirs and fluxes associated with the global water and energy cycle, including their spatial and temporal variability. through integration of all necessary observations and research tools, To this end, in conjunction with NASA's Earth science research strategy, the overarching long-term NASA Energy and Water Cycle Study (NEWS) grand challenge can he summarized as documenting and enabling improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. This challenge requires documenting and predicting trends in the rate of the Earth's water and energy cycling that corresponds to climate change and changes in the frequency and intensity of naturally occurring related meteorological and hydrologic events, which may vary as climate may vary in the future. The cycling of water and energy has obvious and significant implications for the health and prosperity of our society. The importance of documenting and predicting water and energy cycle variations and extremes is necessary to accomplish this benefit to society.

  7. Technical Meeting on Fast Reactors and Related Fuel Cycle Facilities with Improved Economic Characteristics. Working Material

    International Nuclear Information System (INIS)

    2013-01-01

    The objectives of the meeting were: - To identify the main issues and technical features that affect capital and energy production costs of fast reactors and related fuel cycle facilities; - To present fast reactor concepts and designs with enhanced economic characteristics, as well as innovative technical solutions (components, subsystems, etc.) that have the potential to reduce the capital costs of fast reactors and related fuel cycle facilities; - To present energy models and advanced tools for the cost assessment of innovative fast reactors and associated nuclear fuel cycles; - To discuss the results of studies and on-going R&D activities that address cost reduction and the future economic competitiveness of fast reactors; and - To identify research and technology development needs in the field, also in view of new IAEA initiatives to help and support Member States in improving the economic competitiveness of fast reactors and associated nuclear fuel cycles

  8. Technical Meeting on Fast Reactors and Related Fuel Cycle Facilities with Improved Economic Characteristics. Presentations

    International Nuclear Information System (INIS)

    2013-01-01

    The objectives of the meeting were: • To identify the main issues and technical features that affect capital and energy production costs of fast reactors and related fuel cycle facilities; • To present fast reactor concepts and designs with enhanced economic characteristics, as well as innovative technical solutions (components, subsystems, etc.) that have the potential to reduce the capital costs of fast reactors and related fuel cycle facilities; • To present energy models and advanced tools for the cost assessment of innovative fast reactors and associated nuclear fuel cycles; • To discuss the results of studies and ongoing R&D activities that address cost reduction and the future economic competitiveness of fast reactors; • To identify research and technology development needs in the field, also in view of new IAEA initiatives to help and support Member States in improving the economic competitiveness of fast reactors and associated nuclear fuel cycles

  9. Engaging service providers in improving industry performance

    International Nuclear Information System (INIS)

    Oberth, R.

    2012-01-01

    Effective task leadership is the key to achieving results in the nuclear industry and in most other industries. One of the themes of this conference is to discuss how the nuclear industry can undertake Issue-Identification and Definition as a means of 'identifying what needs attention' and then 'defining what needs to be done to make that happen'. I will explore this theme from the perspective of the 'Service Provider' - which by the definition of this conference includes everyone not within an operating utility - meaning 'those involved in everything from inspection and repair to research and plant architecture' - basically the member companies of my association, OCI. Our members take the definition of the roles and responsibilities of the 'Service Provider' community very seriously. In the context of this discussion a key utility function is the early definition of requirements and expectations of Service Providers in supplying to these requirements. Let's explore for a moment the Service Provider role and perspective. Service Providers are by nature pro-active - they seek ways to engage with utilities (and tier one vendors) to solve problems and achieve good outcomes. They come to industry conferences like this one to learn about upcoming utility programs and supply opportunities and how they can improve performance. Service Providers particularly want to hear senior utility people comment on emerging issues even those at the very early identification stage. Some Clarification of Roles is in Order - as that is the focus of this conference: 'Issue-Identification and Definition'. 'Issue-Identification' is the utility's job - it is the utility's role to identify as early as possible 'what needs attention and what their needs and expectations are'. This takes place before service provider engagement. 'Issue-Definition' is more challenging. It means 'determining and prioritizing what needs to be done to deal with the situation at hand'. This typically involves

  10. Improvement to the pattern of control rods of the equilibrium cycle of 18 months for the CLV using bio-inspired algorithms

    International Nuclear Information System (INIS)

    Perusquia, R.; Ortiz, J.J.; Montes, J.L.

    2003-01-01

    Nowadays in the National Institute of Nuclear Research are carried out studies with some bio-inspired optimization techniques to improve the performance of the fuel cycles of the boiling water reactors of the Laguna Verde power plant (CLV). In the present work two bio-inspired techniques were applied with the purpose of improving the performance of a balance cycle of 18 months developed for the CLV: genetic algorithms (AG) and systems based on ants colonies (SCH). The design of the reference cycle it represents in several aspects an optimal cycle proposed starting from the experience of several operation decades with the boiling water reactors (BWR initials for Boiling Water Reactor) in the world. To try to improve their performance is beforehand a difficult challenge and it puts on test the feasibility of the optimization methods in the reloads design. The study of the bio-inspired techniques was centered exclusively on the obtaining of the control rod patterns (PBC) trying to overcome the capacity factor reached in the design of the reference cycle. It was fixed the cycle length such that the decrease of the coast down period would represent an increase of the capacity factor of the cycle; so that, it diminishes the annual cost associated with the capital cost of the plant. As consequence of the study, was found that the algorithm based on the ants colonies reaches to diminish the coast down period in five and half days respect to the original balance cycle, what represents an annual saving of $US 74,000. Since the original cycle was optimized, the above-mentioned, shows the ability of the SCH for the optimization of the cycle design. With the AG it was reach to approach to the original balance cycle with a coast down period greater in seven days estimating an annual penalization of $US 130,000. (Author)

  11. A unified model of combined energy systems with different cycle modes and its optimum performance characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yue [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); College of Information Science and Engineering, Huaqiao University, Quanzhou 362021 (China); Hu, Weiqiang [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Ou Congjie [College of Information Science and Engineering, Huaqiao University, Quanzhou 362021 (China); Chen Jincan [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China)], E-mail: jcchen@xmu.edu.cn

    2009-06-15

    A unified model is presented for a class of combined energy systems, in which the systems mainly consist of a heat engine, a combustor and a counter-flow heat exchanger and the heat engine in the systems may have different thermodynamic cycle modes such as the Brayton cycle, Carnot cycle, Stirling cycle, Ericsson cycle, and so on. Not only the irreversibilities of the heat leak and finite-rate heat transfer but also the different cycle modes of the heat engine are considered in the model. On the basis of Newton's law, expressions for the overall efficiency and power output of the combined energy system with an irreversible Brayton cycle are derived. The maximum overall efficiency and power output and other relevant parameters are calculated. The general characteristic curves of the system are presented for some given parameters. Several interesting cases are discussed in detail. The results obtained here are very general and significant and can be used to discuss the optimal performance characteristics of a class of combined energy systems with different cycle modes. Moreover, it is significant to point out that not only the important conclusions obtained in Bejan's first combustor model and Peterson's general combustion driven model but also the optimal performance of a class of solar-driven heat engine systems can be directly derived from the present paper under some limit conditions.

  12. A unified model of combined energy systems with different cycle modes and its optimum performance characteristics

    International Nuclear Information System (INIS)

    Zhang Yue; Hu, Weiqiang; Ou Congjie; Chen Jincan

    2009-01-01

    A unified model is presented for a class of combined energy systems, in which the systems mainly consist of a heat engine, a combustor and a counter-flow heat exchanger and the heat engine in the systems may have different thermodynamic cycle modes such as the Brayton cycle, Carnot cycle, Stirling cycle, Ericsson cycle, and so on. Not only the irreversibilities of the heat leak and finite-rate heat transfer but also the different cycle modes of the heat engine are considered in the model. On the basis of Newton's law, expressions for the overall efficiency and power output of the combined energy system with an irreversible Brayton cycle are derived. The maximum overall efficiency and power output and other relevant parameters are calculated. The general characteristic curves of the system are presented for some given parameters. Several interesting cases are discussed in detail. The results obtained here are very general and significant and can be used to discuss the optimal performance characteristics of a class of combined energy systems with different cycle modes. Moreover, it is significant to point out that not only the important conclusions obtained in Bejan's first combustor model and Peterson's general combustion driven model but also the optimal performance of a class of solar-driven heat engine systems can be directly derived from the present paper under some limit conditions

  13. Catalytic performance improvement of styrene hydrogenation in trickle bed reactor by using periodic operation

    International Nuclear Information System (INIS)

    Wongkia, Atittahn; Praserthdam, Piyasan; Assabumrungrat, Suttichai; Suriye, Kongkiat; Nonkhamwong, Anuwat

    2013-01-01

    We investigated the catalytic performance improvement of styrene hydrogenation in a trickle bed reactor by using periodic operation. The effects of cycle period and split on relative conversion, which is defined as styrene conversion obtained from periodic operation over that from steady state operation, were examined at various operating conditions including gas and average liquid flow rates, pressure and temperature. The experimental results reveal that both cycle period and split have strong influence on the catalytic performance. The fast mode (short cycle period) is a favorable condition. The improvement by the periodic operation becomes less pronounced for operations at high average liquid flow rate, pressure and temperature. From this study, a maximum improvement of styrene conversion of 18% is observed

  14. Catalytic performance improvement of styrene hydrogenation in trickle bed reactor by using periodic operation

    Energy Technology Data Exchange (ETDEWEB)

    Wongkia, Atittahn; Praserthdam, Piyasan; Assabumrungrat, Suttichai [Chulalongkorn University, Bangkok (Thailand); Suriye, Kongkiat; Nonkhamwong, Anuwat [SCG Chemicals Co. Ltd., Bangkok (Thailand)

    2013-03-15

    We investigated the catalytic performance improvement of styrene hydrogenation in a trickle bed reactor by using periodic operation. The effects of cycle period and split on relative conversion, which is defined as styrene conversion obtained from periodic operation over that from steady state operation, were examined at various operating conditions including gas and average liquid flow rates, pressure and temperature. The experimental results reveal that both cycle period and split have strong influence on the catalytic performance. The fast mode (short cycle period) is a favorable condition. The improvement by the periodic operation becomes less pronounced for operations at high average liquid flow rate, pressure and temperature. From this study, a maximum improvement of styrene conversion of 18% is observed.

  15. Improving File System Performance by Striping

    Science.gov (United States)

    Lam, Terance L.; Kutler, Paul (Technical Monitor)

    1998-01-01

    This document discusses the performance and advantages of striped file systems on the SGI AD workstations. Performance of several striped file system configurations are compared and guidelines for optimal striping are recommended.

  16. Performance analysis of a bio-gasification based combined cycle power plant employing indirectly heated humid air turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S., E-mail: sankha.deepp@gmail.com; Mondal, P., E-mail: mondal.pradip87@gmail.com; Ghosh, S., E-mail: sudipghosh.becollege@gmail.com [Department of Mechanical Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah – 711103, West Bengal (India)

    2016-07-12

    Rapid depletion of fossil fuel has forced mankind to look into alternative fuel resources. In this context, biomass based power generation employing gas turbine appears to be a popular choice. Bio-gasification based combined cycle provides a feasible solution as far as grid-independent power generation is concerned for rural electrification projects. Indirectly heated gas turbine cycles are promising alternatives as they avoid downstream gas cleaning systems. Advanced thermodynamic cycles have become an interesting area of study to improve plant efficiency. Water injected system is one of the most attractive options in this field of applications. This paper presents a theoretical model of a biomass gasification based combined cycle that employs an indirectly heated humid air turbine (HAT) in the topping cycle. Maximum overall electrical efficiency is found to be around 41%. Gas turbine specific air consumption by mass is minimum when pressure ratio is 6. The study reveals that, incorporation of the humidification process helps to improve the overall performance of the plant.

  17. Performance samples on academic tasks : improving prediction of academic performance

    NARCIS (Netherlands)

    Tanilon, Jenny

    2011-01-01

    This thesis is about the development and validation of a performance-based test, labeled as Performance Samples on academic tasks in Education and Child Studies (PSEd). PSEd is designed to identify students who are most able to perform the academic tasks involved in an Education and Child Studies

  18. Sootblowing optimization for improved boiler performance

    Science.gov (United States)

    James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J.

    2012-12-25

    A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

  19. Power generation and heating performances of integrated system of ammonia–water Kalina–Rankine cycle

    International Nuclear Information System (INIS)

    Zhang, Zhi; Guo, Zhanwei; Chen, Yaping; Wu, Jiafeng; Hua, Junye

    2015-01-01

    Highlights: • Integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) is investigated. • Ammonia–water Rankine cycle is operated for cogenerating room heating-water in winter. • Kalina cycle with higher efficiency is operated for power generation in other seasons. • Power recovery efficiency accounts thermal efficiency and waste heat absorbing ratio. • Heating water with 70 °C and capacity of 55% total reclaimed heat load is cogenerated. - Abstract: An integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) for power generation and heating is introduced. The Kalina cycle has large temperature difference during evaporation and small one during condensation therefore with high thermal efficiency for power generation, while the ammonia–water Rankine cycle has large temperature difference during condensation as well as evaporation, thus it can be adopted to generate heating-water as a by-product in winter. The integrated system is based on the Kalina cycle and converted to the Rankine cycle with a set of valves. The performances of the AWKRC system in different seasons with corresponding cycle loops were studied and analyzed. When the temperatures of waste heat and cooling water are 300 °C and 25 °C respectively, the thermal efficiency and power recovery efficiency of Kalina cycle are 20.9% and 17.4% respectively in the non-heating seasons, while these efficiencies of the ammonia–water Rankine cycle are 17.1% and 13.1% respectively with additional 55.3% heating recovery ratio or with comprehensive efficiency 23.7% higher than that of the Kalina cycle in heating season

  20. Football to Improve Math and Reading Performance

    Science.gov (United States)

    Van Klaveren, Chris; De Witte, Kristof

    2015-01-01

    Schools frequently increase the instructional time to improve primary school children's math and reading skills. There is, however, little evidence that math and reading skills are effectively improved by these instruction-time increases. This study evaluates "Playing for Success" (PfS), an extended school day program for underachieving…

  1. Football to improve math and reading performance

    NARCIS (Netherlands)

    Van Klaveren, Chris; De Witte, Kristof

    2015-01-01

    Schools frequently increase the instructional time to improve primary school children's math and reading skills. There is, however, little evidence that math and reading skills are effectively improved by these instruction-time increases. This study evaluates ‘Playing for Success’ (PfS), an extended

  2. Performance investigation on a 4-bed adsorption desalination cycle with internal heat recovery scheme

    KAUST Repository

    Thu, Kyaw

    2016-10-08

    Multi-bed adsorption cycle with the internal heat recovery between the condenser and the evaporator is investigated for desalination application. A numerical model is developed for a 4-bed adsorption cycle implemented with the master-and-slave configuration and the aforementioned internal heat recovery scheme. The present model captures the reversed adsorption/desorption phenomena frequently associated with the unmatched switching periods. Mesoporous silica gel and water vapor emanated from the evaporation of the seawater are employed as the adsorbent and adsorbate pair. The experimental data and investigation for such configurations are reported for the first time at heat source temperatures from 50 °C to 70 °C. The numerical model is validated rigorously and the parametric study is conducted for the performance of the cycle at assorted operation conditions such as hot and cooling water inlet temperatures and the cycle times. The specific daily water production (SDWP) of the present cycle is found to be about 10 m/day per tonne of silica gel for the heat source temperature at 70 °C. Performance comparison is conducted for various types of adsorption desalination cycles. It is observed that the AD cycle with the current configuration provides superior performance whilst is operational at unprecedentedly low heat source temperature as low as 50 °C.

  3. Intradialytic aerobic cycling exercise alleviates inflammation and improves endothelial progenitor cell count and bone density in hemodialysis patients.

    Science.gov (United States)

    Liao, Min-Tser; Liu, Wen-Chih; Lin, Fu-Huang; Huang, Ching-Feng; Chen, Shao-Yuan; Liu, Chuan-Chieh; Lin, Shih-Hua; Lu, Kuo-Cheng; Wu, Chia-Chao

    2016-07-01

    Inflammation, endothelial dysfunction, and mineral bone disease are critical factors contributing to morbidity and mortality in hemodialysis (HD) patients. Physical exercise alleviates inflammation and increases bone density. Here, we investigated the effects of intradialytic aerobic cycling exercise on HD patients. Forty end-stage renal disease patients undergoing HD were randomly assigned to either an exercise or control group. The patients in the exercise group performed a cycling program consisting of a 5-minute warm-up, 20 minutes of cycling at the desired workload, and a 5-minute cool down during 3 HD sessions per week for 3 months. Biochemical markers, inflammatory cytokines, nutritional status, the serum endothelial progenitor cell (EPC) count, bone mineral density, and functional capacity were analyzed. After 3 months of exercise, the patients in the exercise group showed significant improvements in serum albumin levels, the body mass index, inflammatory cytokine levels, and the number of cells positive for CD133, CD34, and kinase insert domain-conjugating receptor. Compared with the exercise group, the patients in the control group showed a loss of bone density at the femoral neck and no increases in EPCs. The patients in the exercise group also had a significantly greater 6-minute walk distance after completing the exercise program. Furthermore, the number of EPCs significantly correlated with the 6-minute walk distance both before and after the 3-month program. Intradialytic aerobic cycling exercise programs can effectively alleviate inflammation and improve nutrition, bone mineral density, and exercise tolerance in HD patients.

  4. Performance analysis of a Miller cycle engine by an indirect analysis method with sparking and knock in consideration

    International Nuclear Information System (INIS)

    Wang, Yuanfeng; Zu, Bingfeng; Xu, Yuliang; Wang, Zhen; Liu, Jie

    2016-01-01

    Highlights: • A quasi-dimensional model was adopted to study Miller cycle engine’s performance. • A new indirect performance analysis method was proposed. • The definition of effective compression ratio was modified. • The modified effective compression ratio takes the trapped mixture mass in account. • The factors limiting the fuel economy in Miller cycle engine were found out. - Abstract: In this paper, a full-factorial design of experiment was applied to thoroughly investigate the effects of compression ratio, intake valve closing retardation angle, and engine speed on the fuel consumption performance and power performance of the Miller cycle engine based on a quasi-dimensional simulation model. A new indirect analysis method based on formula derivation and main effect analysis was proposed to simplify the complex relationship between the design factors and the performance parameters. The definition of effective compression ratio was modified to take account of the actual mass of mixture trapped in the cylinder. The results show that the distributions of brake mean effective pressure and brake specific fuel consumption can be regarded as the re-organization results from the distributions of volumetric efficiency and indicated efficiency. The intake valve closing retardation angle has a strong negative correlation with volumetric efficiency. The modified effective compression ratio is the approximate product of the compression ratio and the volumetric efficiency, and makes obvious effects on the distribution of the indicated efficiency. Therefore the combustion process is co-evolved with the intake process in a Miller cycle engine. The further improvement of brake specific fuel consumption is mainly limited by four factors, i.e., the back flow loss, the exergy loss, the incomplete expansion loss, and the combustion loss. The improvement of fuel consumption performance is at a cost of power performance, and the trade-off between the both essentially

  5. The use of polybenzimidazole membranes in vanadium redox flow batteries leading to increased coulombic efficiency and cycling performance

    International Nuclear Information System (INIS)

    Zhou, X.L.; Zhao, T.S.; An, L.; Wei, L.; Zhang, C.

    2015-01-01

    An issue with conventional vanadium redox flow batteries (VRFB) with Nafion membranes is the crossover of vanadium ions, resulting in low coulombic efficiency and rapid decay in capacity. In this work, a VRFB with a polybenzimidazole (PBI) membrane is tested and compared with the Nafion system. Results show that the PBI-based VRFB exhibits a substantially higher coulombic efficiency of up to 99% at current densities ranging from 20 mA cm −2 to 80 mA cm −2 . More importantly, it is demonstrated that the PBI-based VRFB has a capacity decay rate of as low as 0.3% per cycle, which is four times lower than that of the Nafion system (1.3% per cycle). The improved coulombic efficiency and cycling performance are attributed to the low crossover of vanadium ions through the PBI membrane

  6. Bioinspired Polymeric Photonic Crystals for High Cycling pH-Sensing Performance.

    Science.gov (United States)

    Fei, Xiang; Lu, Tao; Ma, Jun; Wang, Wanlin; Zhu, Shenmin; Zhang, Di

    2016-10-12

    Artificial photonic crystals (PCs) have been extensively studied to improve the sensing performance of poly(acrylic acid) (PAAc), as it can transform the PAAc volume change into optical signal which is easier to read. Nevertheless, these PCs are limited by the monostructure. We herein developed new photonic crystals (PCs) by coating acrylic acid and acrylamide (AAm) via in situ copolymerization onto Papilio paris wings having hierarchical, lamellar structure. Our PCs exhibited high performance of color tunability to environmental pH, as detected by reflectance spectra and visual observation. The introduction of AAm into the system created covalent bonding which robustly bridged the polymer with the wings, leading to an accurate yet broad variation of reflection wavelength to gauge environmental pH. The reflection wavelength can be tailored by the refractive index of the lamellar interspacing due to the swelling/deswelling of the polymer. The mechanism is not only supported by experimenta but proved by finite-difference time-domain simulation. Moreover, It is worth noting that the covalent bonding has provided the PCs-based pH sensor with high cycling performance, implying great potential in practical applications. The simple fabrication process is applicable to the development of a wide variety of stimuli-responsive PCs taking advantage of other polymers.

  7. Effects of caffeine on neuromuscular fatigue and performance during high-intensity cycling exercise in moderate hypoxia.

    Science.gov (United States)

    Smirmaul, Bruno P C; de Moraes, Antonio Carlos; Angius, Luca; Marcora, Samuele M

    2017-01-01

    To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg -1 ) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design. Caffeine significantly improved time to exhaustion by 12%. A significant decrease in subjective fatigue was found after caffeine consumption. Perception of effort and surface electromyographic signal amplitude of the vastus lateralis were lower and heart rate was higher in the caffeine condition when compared to placebo. However, caffeine did not reduce the peripheral and central fatigue induced by high-intensity cycling exercise in moderate hypoxia. The caffeine-induced improvement in time to exhaustion during high-intensity cycling exercise in moderate hypoxia seems to be mediated by a reduction in perception of effort, which occurs despite no reduction in neuromuscular fatigue.

  8. Use of ICSI in IVF cycles in women with tubal ligation does not improve pregnancy or live birth rates.

    Science.gov (United States)

    Grimstad, F W; Nangia, Ajay K; Luke, B; Stern, J E; Mak, W

    2016-12-01

    Does ICSI improve outcomes in ART cycles without male factor, specifically in couples with a history of tubal ligation as their infertility diagnosis? The use of ICSI showed no significant improvement in fertilization rate and resulted in lower pregnancy and live birth (LB) rates for women with the diagnosis of tubal ligation and no male factor. Prior studies have suggested that ICSI use does not improve fertilization, pregnancy or LB rates in couples with non-male factor infertility. However, it is unknown whether couples with tubal ligation only diagnosis and therefore iatrogenic infertility could benefit from the use of ICSI during their ART cycles. Longitudinal cohort of nationally reported cycles in the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS) of ART cycles performed in the USA between 2004 and 2012. There was a total of 8102 first autologous fresh ART cycles from women with the diagnosis of tubal ligation only and no reported male factor in the SART database. Of these, 957 were canceled cycles and were excluded from the final analysis. The remaining cycles were categorized by the use of conventional IVF (IVF, n = 3956 cycles) or ICSI (n = 3189 cycles). The odds of fertilization, clinical intrauterine gestation (CIG) and LB were calculated by logistic regression modeling, and the adjusted odds ratios (AORs) with 95% confidence intervals were calculated by adjusting for the confounders of year of treatment, maternal age, race and ethnicity, gravidity, number of oocytes retrieved, day of embryo transfer and number of embryos transferred. The main outcome measures of the study were odds of fertilization (2PN/total oocytes), clinical intrauterine gestation (CIG/cycle) and live birth (LB/cycle). The fertilization rate was higher in the ICSI versus IVF group (57.5% vs 49.1%); however, after adjustment this trend was no longer significant (AOR 1.14, 0.97-1.35). Interestingly, both odds of CIG (AOR 0.78, 0

  9. 7804 PERFORMANCE OF IMPROVED BEAN VARIETIES IN ...

    African Journals Online (AJOL)

    Win7Ent

    2013-06-03

    Jun 3, 2013 ... 3. June 2013. ABSTRACT. A project aimed at improving bean production in Kigoma Region was carried out ... Some rain is required during the flowering and pod setting stages [2]. ..... library.ciat.cgiar.org/articulos/ciat/paperb.

  10. Performance improvement of professional printing systems : from theory to practice

    NARCIS (Netherlands)

    Ezzeldin Mahdy Abdelmonem, M.

    2012-01-01

    Performance Improvement of Professional Printing Systems: from theory to practice Markets demand continuously for higher quality, higher speed, and more energy-efficient professional printers. In this thesis, control strategies have been developed to improve the performance of both professional

  11. Performance Results of CMMI-Based Process Improvement

    National Research Council Canada - National Science Library

    Gibson, Diane L; Goldenson, Dennis R; Kost, Keith

    2006-01-01

    .... There now is evidence that process improvement using the CMMI Product Suite can result in improvements in schedule and cost performance, product quality, return on investment and other measures of performance outcome...

  12. Can visual arts training improve physician performance?

    Science.gov (United States)

    Katz, Joel T; Khoshbin, Shahram

    2014-01-01

    Clinical educators use medical humanities as a means to improve patient care by training more self-aware, thoughtful, and collaborative physicians. We present three examples of integrating fine arts - a subset of medical humanities - into the preclinical and clinical training as models that can be adapted to other medical environments to address a wide variety of perceived deficiencies. This novel teaching method has promise to improve physician skills, but requires further validation.

  13. Can Visual Arts Training Improve Physician Performance?

    Science.gov (United States)

    Katz, Joel T.; Khoshbin, Shahram

    2014-01-01

    Clinical educators use medical humanities as a means to improve patient care by training more self-aware, thoughtful, and collaborative physicians. We present three examples of integrating fine arts — a subset of medical humanities — into the preclinical and clinical training as models that can be adapted to other medical environments to address a wide variety of perceived deficiencies. This novel teaching method has promise to improve physician skills, but requires further validation. PMID:25125749

  14. Improvement of irradiation facilities performance in JMTR

    International Nuclear Information System (INIS)

    Kanno, Masaru; Sakurai, Susumu; Honma, Kenzo; Sagawa, Hisashi; Nakazaki, Chousaburo

    1999-01-01

    Various kinds of irradiation facilities are installed in the JMTR for the purpose of irradiation tests on fuels and materials and of producing radioisotopes. The irradiation facilities have been improved so far at every opportunity of new irradiation requirements and of renewing them which reached the design lifetime. Of these irradiation facilities, improvements of the power ramping test facility (BOCA/OSF-1 facility) and the hydraulic rabbit No.2 (HR-2 facility) are described here. (author)

  15. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

    Directory of Open Access Journals (Sweden)

    Gregory E. P. Pearcey

    2017-12-01

    Full Text Available Spinal cord excitability, as assessed by modulation of Hoffmann (H- reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM, sprints with sensory stimulation (SPRINT + STIM and sprints without stimulation (SPRINT. Seven participants also performed a fourth session (CONTROL, which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output

  16. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

    Science.gov (United States)

    Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

    2017-01-01

    Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared

  17. Performance analysis and binary working fluid selection of combined flash-binary geothermal cycle

    International Nuclear Information System (INIS)

    Zeyghami, Mehdi

    2015-01-01

    Performance of the combined flash-binary geothermal power cycle for geofluid temperatures between 150 and 250 °C is studied. A thermodynamic model is developed, and the suitable binary working fluids for different geofluid temperatures are identified from a list of thirty working fluid candidates, consisting environmental friendly refrigerants and hydrocarbons. The overall system exergy destruction and Vapor Expansion Ratio across the binary cycle turbine are selected as key performance indicators. The results show that for low-temperature heat sources using refrigerants as binary working fluids result in higher overall cycle efficiency and for medium and high-temperature resources, hydrocarbons are more suitable. For combined flash-binary cycle, secondary working fluids; R-152a, Butane and Cis-butane show the best performances at geofluid temperatures 150, 200 and 250 °C respectively. The overall second law efficiency is calculated as high as 0.48, 0.55 and 0.58 for geofluid temperatures equal 150, 200 and 250 °C respectively. The flash separator pressure found to has important effects on cycle operation and performance. Separator pressure dictates the work production share of steam and binary parts of the system. And there is an optimal separator pressure at which overall exergy destruction of the cycle achieves its minimum value. - Highlights: • Performance of the combined flash-binary geothermal cycle is investigated. • Thirty different fluids are screened to find the most suitable ORC working fluid. • Optimum cycle operation conditions presented for geofluids between 150 °C and 250 °C. • Refrigerants are more suitable for the ORC at geothermal sources temperature ≤200 °C. • Hydrocarbons are more suitable for the ORC at geothermal sources temperature >200 °C

  18. Hydraulic performance of compacted clay liners under simulated daily thermal cycles.

    Science.gov (United States)

    Aldaeef, A A; Rayhani, M T

    2015-10-01

    Compacted clay liners (CCLs) are commonly used as hydraulic barriers in several landfill applications to isolate contaminants from the surrounding environment and minimize the escape of leachate from the landfill. Prior to waste placement in landfills, CCLs are often exposed to temperature fluctuations which can affect the hydraulic performance of the liner. Experimental research was carried out to evaluate the effects of daily thermal cycles on the hydraulic performance of CCLs under simulated landfill conditions. Hydraulic conductivity tests were conducted on different soil specimens after being exposed to various thermal and dehydration cycles. An increase in the CCL hydraulic conductivity of up to one order of magnitude was recorded after 30 thermal cycles for soils with low plasticity index (PI = 9.5%). However, medium (PI = 25%) and high (PI = 37.2%) plasticity soils did not show significant hydraulic deviation due to their self-healing potential. Overlaying the CCL with a cover layer minimized the effects of daily thermal cycles, and maintained stable hydraulic performance in the CCLs even after exposure to 60 thermal cycles. Wet-dry cycles had a significant impact on the hydraulic aspect of low plasticity CCLs. However, medium and high plasticity CCLs maintained constant hydraulic performance throughout the test intervals. The study underscores the importance of protecting the CCL from exposure to atmosphere through covering it by a layer of geomembrane or an interim soil layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Improved Fatigue Performance of Threaded Drillstring Connections by Cold Rolling

    Energy Technology Data Exchange (ETDEWEB)

    Kristoffersen, Steinar

    2002-01-01

    pits inside the pipe. Therefore, an optimisation of the roll geometry and rolling parameters was not possible. However, a significant fatigue life improvement was achieved. Based on experiments, a roller with similar profile as the thread root is recommended. A rolling force of maximum 20 kN is recommended to minimise the possibility of damaging the thread profile. Shallow cracks were observed typically when 5% of the fatigue life had expired. Re-rolling after 50% of expected improved fatigue life, when also short cracks were observed in the notch roots further increased the fatigue improvement. Pretensioned small steel specimens with a notch were used to simulate cold rolled threads. The specimens were fatigue tested in tension with minimum load close to zero. Pretensioning increased the fatigue life from approximately 50 000 cycles to an infinite number of cycles. In these tests non-propagating cracks of typically 0.4 mm length were found. The benefit from pretensioning gradually disappeared with increasing mean stress. FE analyses indicated that an almost instant relaxation of residual stresses to a level with no monotonic strain hardening from preloading would take place when cycled at moderate mean stress. Cycled at low mean stress, an instant relaxation of the surface layer was found in analysis. All observations from notched pretensioned fatigue specimens were in good agreement with the available literature. However, preloading was found to be strain rate dependent in tests where a pretension load held for 2 minutes gave a longer fatigue life than a sinusoidal loading-unloading cycle performed over a one minute interval. Strain hardening was found not contributing to the fatigue life improvement, whereas the polishing effect from improved surface quality after cold rolling increased the fatigue initiation period. However, residual stress and subsequent early crack closure was the dominating effect at moderate cyclic mean loads. The material data required to

  20. Improving Student Performance Using Nudge Analytics

    Science.gov (United States)

    Feild, Jacqueline

    2015-01-01

    Providing students with continuous and personalized feedback on their performance is an important part of encouraging self regulated learning. As part of our higher education platform, we built a set of data visualizations to provide feedback to students on their assignment performance. These visualizations give students information about how they…

  1. How Six Sigma Methodology Improved Doctors' Performance

    Science.gov (United States)

    Zafiropoulos, George

    2015-01-01

    Six Sigma methodology was used in a District General Hospital to assess the effect of the introduction of an educational programme to limit unnecessary admissions. The performance of the doctors involved in the programme was assessed. Ishikawa Fishbone and 5 S's were initially used and Pareto analysis of their findings was performed. The results…

  2. Using Performance Task Data to Improve Instruction

    Science.gov (United States)

    Abbott, Amy L.; Wren, Douglas G.

    2016-01-01

    Two well-accepted ideas among educators are (a) performance assessment is an effective means of assessing higher-order thinking skills and (b) data-driven instruction planning is a valuable tool for optimizing student learning. This article describes a locally developed performance task (LDPT) designed to measure critical thinking, problem…

  3. Performance comparison of different thermodynamic cycles for an innovative central receiver solar power plant

    Science.gov (United States)

    Reyes-Belmonte, Miguel A.; Sebastián, Andrés; González-Aguilar, José; Romero, Manuel

    2017-06-01

    The potential of using different thermodynamic cycles coupled to a solar tower central receiver that uses a novel heat transfer fluid is analyzed. The new fluid, named as DPS, is a dense suspension of solid particles aerated through a tubular receiver used to convert concentrated solar energy into thermal power. This novel fluid allows reaching high temperatures at the solar receiver what opens a wide range of possibilities for power cycle selection. This work has been focused into the assessment of power plant performance using conventional, but optimized cycles but also novel thermodynamic concepts. Cases studied are ranging from subcritical steam Rankine cycle; open regenerative Brayton air configurations at medium and high temperature; combined cycle; closed regenerative Brayton helium scheme and closed recompression supercritical carbon dioxide Brayton cycle. Power cycle diagrams and working conditions for design point are compared amongst the studied cases for a common reference thermal power of 57 MWth reaching the central cavity receiver. It has been found that Brayton air cycle working at high temperature or using supercritical carbon dioxide are the most promising solutions in terms of efficiency conversion for the power block of future generation by means of concentrated solar power plants.

  4. Industry activities to improve valve performance

    Energy Technology Data Exchange (ETDEWEB)

    Callaway, C.

    1996-12-01

    Motor-operated valve issues refuse to go away. For over a decade the industry and the NRC have been focusing extraordinary resources on assuring these special components operate when called upon. Now that industry has fixed the design deficiencies, it is focusing on assuring that they perform their safety function within the current licensing basis for the remainder of plant life. NEI supported the efforts by ASME to develop OMN-1 and was encouraged that the industry and the NRC worked together to develop risk and performance based approaches to maintain MOV performance.

  5. Does Advertising Spending Improve Sales Performance?

    DEFF Research Database (Denmark)

    Assaf, A. George; Josiassen, Alexander; Mattila, Anna S.

    2015-01-01

    Hotel managers and investors commonly analyze the impact of advertising spending on firm performance. This paper investigates such an impact using a comprehensive framework incorporating the moderating effects of hotel size and star ratings. We estimated sales performance via dynamic, stochastic...... frontier modelling. Using longitudinal data from a sample of Slovenian and Croatian hotels, we demonstrate that advertising spending has a positive impact on hotel sales performance, and that the relationship strengthens for larger hotels and hotels with higher star ratings. Theoretical and managerial...

  6. Life cycle cost-based risk model for energy performance contracting retrofits

    Science.gov (United States)

    Berghorn, George H.

    Buildings account for 41% of the primary energy consumption in the United States, nearly half of which is accounted for by commercial buildings. Among the greatest energy users are those in the municipalities, universities, schools, and hospitals (MUSH) market. Correctional facilities are in the upper half of all commercial building types for energy intensity. Public agencies have experienced reduced capital budgets to fund retrofits; this has led to the increased use of energy performance contracts (EPC), which are implemented by energy services companies (ESCOs). These companies guarantee a minimum amount of energy savings resulting from the retrofit activities, which in essence transfers performance risk from the owner to the contractor. Building retrofits in the MUSH market, especially correctional facilities, are well-suited to EPC, yet despite this potential and their high energy intensities, efficiency improvements lag behind that of other public building types. Complexities in project execution, lack of support for data requests and sub-metering, and conflicting project objectives have been cited as reasons for this lag effect. As a result, project-level risks must be understood in order to support wider adoption of retrofits in the public market, in particular the correctional facility sub-market. The goal of this research is to understand risks related to the execution of energy efficiency retrofits delivered via EPC in the MUSH market. To achieve this goal, in-depth analysis and improved understanding was sought with regard to ESCO risks that are unique to EPC in this market. The proposed work contributes to this understanding by developing a life cycle cost-based risk model to improve project decision making with regard to risk control and reduction. The specific objectives of the research are: (1) to perform an exploratory analysis of the EPC retrofit process and identify key areas of performance risk requiring in-depth analysis; (2) to construct a

  7. Improvement actions in waste management systems at the provincial scale based on a life cycle assessment evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Rigamonti, L., E-mail: lucia.rigamonti@polimi.it; Falbo, A.; Grosso, M.

    2013-11-15

    Highlights: • LCA was used for evaluating the performance of four provincial waste management systems. • Milano, Bergamo, Pavia and Mantova (Italy) are the provinces selected for the analysis. • Most of the data used to model the systems are primary. • Significant differences were found among the provinces located in the same Region. • LCA was used as a decision-supporting tool by Regione Lombardia. - Abstract: This paper reports some of the findings of the ‘GERLA’ project: GEstione Rifiuti in Lombardia – Analisi del ciclo di vita (Waste management in Lombardia – Life cycle assessment). The project was devoted to support Lombardia Region in the drafting of the new waste management plan by applying a life cycle thinking perspective. The present paper mainly focuses on four Provinces in the Region, which were selected based on their peculiarities. Life cycle assessment (LCA) was adopted as the methodology to assess the current performance of the integrated waste management systems, to discuss strengths and weaknesses of each of them and to design their perspective evolution as of year 2020. Results show that despite a usual business approach that is beneficial to all the provinces, the introduction of technological and management improvements to the system provides in general additional energy and environmental benefits for all four provinces. The same improvements can be easily extended to the whole Region, leading to increased environmental benefits from the waste management sector, in line with the targets set by the European Union for 2020.

  8. Improvement actions in waste management systems at the provincial scale based on a life cycle assessment evaluation

    International Nuclear Information System (INIS)

    Rigamonti, L.; Falbo, A.; Grosso, M.

    2013-01-01

    Highlights: • LCA was used for evaluating the performance of four provincial waste management systems. • Milano, Bergamo, Pavia and Mantova (Italy) are the provinces selected for the analysis. • Most of the data used to model the systems are primary. • Significant differences were found among the provinces located in the same Region. • LCA was used as a decision-supporting tool by Regione Lombardia. - Abstract: This paper reports some of the findings of the ‘GERLA’ project: GEstione Rifiuti in Lombardia – Analisi del ciclo di vita (Waste management in Lombardia – Life cycle assessment). The project was devoted to support Lombardia Region in the drafting of the new waste management plan by applying a life cycle thinking perspective. The present paper mainly focuses on four Provinces in the Region, which were selected based on their peculiarities. Life cycle assessment (LCA) was adopted as the methodology to assess the current performance of the integrated waste management systems, to discuss strengths and weaknesses of each of them and to design their perspective evolution as of year 2020. Results show that despite a usual business approach that is beneficial to all the provinces, the introduction of technological and management improvements to the system provides in general additional energy and environmental benefits for all four provinces. The same improvements can be easily extended to the whole Region, leading to increased environmental benefits from the waste management sector, in line with the targets set by the European Union for 2020

  9. The model for the strategic management of technology. The improvement cycle and matrixes deployment QFD

    International Nuclear Information System (INIS)

    Benavides Velasco, C. A.; Quintana Garcia, C.

    2007-01-01

    In spite of the importance of innovative firms, few contributions study in depth the strategic management of their technological resources. After describing the process of strategic management of technology, we propose a model that enables the application of that process and guarantees organizational flexibility in technological companies. For it, such a process has been adapted to She wart cycle (Deeming wheel) and combined with the quality function deployment (QFD). As a result, we propose the improvement cycle of technology. It contains two matrixes that allow identifying and prioritizing with greater clarity the activities related to the management of technological resources. (Authors)

  10. Modelling and Improvement of Thermal Cycling in Power Electronics for Motor Drive Applications

    DEFF Research Database (Denmark)

    Vernica, Ionut; Ma, Ke; Blaabjerg, Frede

    2016-01-01

    It is well known that the dynamical change of the thermal stress in the power devices is one of the major factors that have influences on the overall efficiency and reliability of power electronics. The main objective of this paper consists of identifying the main parameters that affect the thermal...... are identified during the acceleration and deceleration periods of the motor. The main causes for these adverse thermal cycles have been presented and, consequently, the influence of the deceleration slope, modulation technique and reactive current on the thermal cycles has been analyzed. Finally, the improved...

  11. Mental Toughness Moderates Social Loafing in Cycle Time-Trial Performance

    Science.gov (United States)

    Haugen, Tommy; Reinboth, Michael; Hetlelid, Ken J.; Peters, Derek M.; Høigaard, Rune

    2016-01-01

    Purpose: The purpose of this study was to determine if mental toughness moderated the occurrence of social loafing in cycle time-trial performance. Method: Twenty-seven men (M[subscript age] = 17.7 years, SD = 0.6) completed the Sport Mental Toughness Questionnaire prior to completing a 1-min cycling trial under 2 conditions: once with individual…

  12. Performance assessment and optimization of an irreversible nano-scale Stirling engine cycle operating with Maxwell-Boltzmann gas

    Science.gov (United States)

    Ahmadi, Mohammad H.; Ahmadi, Mohammad-Ali; Pourfayaz, Fathollah

    2015-09-01

    Developing new technologies like nano-technology improves the performance of the energy industries. Consequently, emerging new groups of thermal cycles in nano-scale can revolutionize the energy systems' future. This paper presents a thermo-dynamical study of a nano-scale irreversible Stirling engine cycle with the aim of optimizing the performance of the Stirling engine cycle. In the Stirling engine cycle the working fluid is an Ideal Maxwell-Boltzmann gas. Moreover, two different strategies are proposed for a multi-objective optimization issue, and the outcomes of each strategy are evaluated separately. The first strategy is proposed to maximize the ecological coefficient of performance (ECOP), the dimensionless ecological function (ecf) and the dimensionless thermo-economic objective function ( F . Furthermore, the second strategy is suggested to maximize the thermal efficiency ( η), the dimensionless ecological function (ecf) and the dimensionless thermo-economic objective function ( F). All the strategies in the present work are executed via a multi-objective evolutionary algorithms based on NSGA∥ method. Finally, to achieve the final answer in each strategy, three well-known decision makers are executed. Lastly, deviations of the outcomes gained in each strategy and each decision maker are evaluated separately.

  13. Variability in Cadence During Forced Cycling Predicts Motor Improvement in Individuals With Parkinson’s Disease

    Science.gov (United States)

    Ridgel, Angela L.; Abdar, Hassan Mohammadi; Alberts, Jay L.; Discenzo, Fred M.; Loparo, Kenneth A.

    2014-01-01

    Variability in severity and progression of Parkinson’s disease symptoms makes it challenging to design therapy interventions that provide maximal benefit. Previous studies showed that forced cycling, at greater pedaling rates, results in greater improvements in motor function than voluntary cycling. The precise mechanism for differences in function following exercise is unknown. We examined the complexity of biomechanical and physiological features of forced and voluntary cycling and correlated these features to improvements in motor function as measured by the Unified Parkinson’s Disease Rating Scale (UPDRS). Heart rate, cadence, and power were analyzed using entropy signal processing techniques. Pattern variability in heart rate and power were greater in the voluntary group when compared to forced group. In contrast, variability in cadence was higher during forced cycling. UPDRS Motor III scores predicted from the pattern variability data were highly correlated to measured scores in the forced group. This study shows how time series analysis methods of biomechanical and physiological parameters of exercise can be used to predict improvements in motor function. This knowledge will be important in the development of optimal exercise-based rehabilitation programs for Parkinson’s disease. PMID:23144045

  14. Improving Operational Risk Management Using Business Performance Management Technologies

    Directory of Open Access Journals (Sweden)

    Bram Pieket Weeserik

    2018-02-01

    Full Text Available Operational Risk Management (ORM comprises the continuous management of risks resulting from: human actions, internal processes, systems, and external events. With increasing requirements, complexity and a growing volume of risks, information systems provide benefits for integrating risk management activities and optimizing performance. Business Performance Management (BPM technologies are believed to provide a solution for effective Operational Risk Management by offering several combined technologies including: work flow, data warehousing, (advanced analytics, reporting and dashboards. BPM technologies can be integrated with an organization’s Planning & Control cycle and related to strategic objectives. This manuscript aims to show how ORM can benefit from BPM technologies via the development and practical validation of a new maturity model. The B4ORM maturity model was developed following the Design Science Research approach. The maturity model relates specific maturity levels of ORM processes with BPM technologies applicable for a specific maturity stage. There appears to be a strong relationship (0.78 with ORM process maturity and supporting BPM technologies. The B4ORM maturity model as described in this manuscript provides an ideal path of BPM technologies related to six distinctive stages of ORM, leading towards technologies suitable for continuous improvement of ORM processes and organization-wide integration.

  15. Warehouse Performance Improvement at Linfox Logistics Indonesia

    OpenAIRE

    Pratama, Riyan Galuh; Simatupang, Togar M

    2013-01-01

    The objective of this research is to provide alternative solutions for Linfox Logistics Indonesia (LLI) in facing warehouse performance issues. The main warehouse performance indicators called Customer Case Filling on Time (CCFOT) and Case Picking Productivity failed to achieve the target. Several analyses were carried out regarding current dispatch process, value stream mapping, and root causes identification. The results find that much waste occurred in dispatch process. Proposed improvemen...

  16. Using Performance Tasks to Improve Quantitative Reasoning in an Introductory Mathematics Course

    Science.gov (United States)

    Kruse, Gerald; Drews, David

    2013-01-01

    A full-cycle assessment of our efforts to improve quantitative reasoning in an introductory math course is described. Our initial iteration substituted more open-ended performance tasks for the active learning projects than had been used. Using a quasi-experimental design, we compared multiple sections of the same course and found non-significant…

  17. Improved Swimming Performance in Hydrodynamically- coupled Airfoils

    Science.gov (United States)

    Heydari, Sina; Shelley, Michael J.; Kanso, Eva

    2017-11-01

    Collective motion is a widespread phenomenon in the animal kingdom from fish schools to bird flocks. Half of the known fish species are thought to exhibit schooling behavior during some phase of their life cycle. Schooling likely occurs to serve multiple purposes, including foraging for resources and protection from predators. Growing experimental and theoretical evidence supports the hypothesis that fish can benefit from the hydrodynamic interactions with their neighbors, but it is unclear whether this requires particular configurations or regulations. Here, we propose a physics-based approach that account for hydrodynamic interactions among swimmers based on the vortex sheet model. The benefit of this model is that it is scalable to a large number of swimmers. We start by examining the case of two swimmers, heaving plates, moving in parallel and in tandem. We find that for the same heaving amplitude and frequency, the coupled-swimmers move faster and more efficiently. This increase in velocity depends strongly on the configuration and separation distance between the swimmers. Our results are consistent with recent experimental findings on heaving airfoils and underline the role of fluid dynamic interactions in the collective behavior of swimmers.

  18. Quasi-static Cycle Performance Analysis of Micro Modular Reactor for Heat Sink Temperature Variation

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seong Kuk; Lee, Jekyoung; Ahn, Yoonhan; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Cha, Jae Eun [KAERI, Daejeon (Korea, Republic of)

    2015-10-15

    A Supercritical CO{sub 2} (S-CO{sub 2}) cycle has potential for high thermal efficiency in the moderate turbine inlet temperature (450 - 750 .deg. C) and achieving compact system size because of small specific volume and simple cycle layouts. Owing to small specific volume of S-CO{sub 2} and the development of heat exchanger technology, it can accomplish complete modularization of the system. The previous works focused on the cycle performance analysis for the design point only. However, the heat sink temperature can be changed depending on the ambient atmosphere condition, i.e. weather, seasonal change. This can influence the compressor inlet temperature, which alters the cycle operating condition overall. To reflect the heat sink temperature variation, a quasi-static analysis code for a simple recuperated S-CO{sub 2} Brayton cycle has been developed by the KAIST research team. Thus, cycle performance analysis is carried out with a compressor inlet temperature variation in this research. In the case of dry air-cooling system, the ambient temperature of the local surrounding can affect the compressor inlet temperature. As the compressor inlet temperature increases, thermal efficiency and generated electricity decrease. As further works, the experiment of S-CO{sub 2} integral test loop will be performed to validate in-house codes, such as KAIST{sub T}MD and the quasi-static code.

  19. A Management Tool for Improvement (Improving) IMS Stations Performance

    International Nuclear Information System (INIS)

    Mohammad, D.; Pantin, A.; Quintana, E.

    2011-01-01

    IMS-Maintenance is a software under development by the personnel of ARN-CTBT office, intended for the technical management of IMS stations under ARN's responsibility. This software integrates the whole control of the equipment in an IMS station, including the management of consumables used in daily or periodic operation. It permits an easy retrieval (access) of the technical features, suppliers, etc. of each item of the equipment, as well as its maintenance history and scheduled task. Although this project is still in a starting phase, a preliminary version of this software is being used in radionuclide station RN01 (Buenos Aires), having already demonstrated its usefulness and potential for the improvement of IMS station management. (authors)

  20. Performance analysis of irreversible quantum Stirling cryogenic refrigeration cycles and their parametric optimum criteria

    International Nuclear Information System (INIS)

    Lin Bihong; Chen Jincan

    2006-01-01

    The influence of both the quantum degeneracy and the finite-rate heat transfer between the working substance and the heat reservoirs on the optimal performance of an irreversible Stirling cryogenic refrigeration cycle using an ideal Fermi or Bose gas as the working substance is investigated, based on the theory of statistical mechanics and thermodynamic properties of ideal quantum gases. The inherent regeneration losses of the cycle are analysed. Expressions for several important performance parameters such as the coefficient of performance, cooling rate and power input are derived. By using numerical solutions, the cooling rate of the cycle is optimized for a given power input. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal regions of the coefficient of performance and power input are determined. In particular, the optimal performance of the cycle in the strong and weak gas degeneracy cases and the high temperature limit are discussed in detail. The analytic expressions of some optimized parameters are derived. Some optimum criteria are given. The distinctions and connections between the Stirling refrigeration cycles working with the ideal quantum and classical gases are revealed

  1. Technical Meeting on Fast Reactors and Related Fuel Cycle Facilities with Improved Economic Characteristics. Working Material

    International Nuclear Information System (INIS)

    2013-01-01

    In recent years, engineering oriented work, rather than basic research and development (R&D), has led to significant progress in improving the economics of innovative fast reactors and associated fuel cycle facilities, while maintaining and even enhancing the safety features of these systems. Optimization of plant size and layout, more compact designs, reduction of the amount of plant materials and the building volumes, higher operating temperatures to attain higher generating efficiencies, improvement of load factor, extended core lifetimes, high fuel burnup, etc. are good examples of achievements to date that have improved the economics of fast neutron systems. The IAEA, through its Technical Working Group on Fast Reactors (TWG-FR) and Technical Working Group on Nuclear Fuel Cycle Options and Spent Fuel Management (TWG-NFCO), devotes many of its initiatives to encouraging technical cooperation and promoting common research and technology development projects among Member States with fast reactor and advanced fuel cycle development programmes, with the general aim of catalysing and accelerating technology advances in these fields. In particular the theme of fast reactor deployment, scenarios and economics has been largely debated during the recent IAEA International Conference on Fast Reactors and Related Fuel Cycles: Safe Technologies and Sustainable Scenarios, held in Paris in March 2013. Several papers presented at this conference discussed the economics of fast reactors from different national and regional perspectives, including business cases, investment scenarios, funding mechanisms and design options that offer significant capital and energy production cost reductions. This Technical Meeting on Fast Reactors and Related Fuel Cycle Facilities with Improved Economic Characteristics addresses Member States’ expressed need for information exchange in the field, with the aim of identifying the main open issues and launching possible initiatives to help and

  2. Partnering through Training and Practice to Achieve Performance Improvement

    Science.gov (United States)

    Lyons, Paul R.

    2010-01-01

    This article presents a partnership effort among managers, trainers, and employees to spring to life performance improvement using the performance templates (P-T) approach. P-T represents a process model as well as a method of training leading to performance improvement. Not only does it add to our repertoire of training and performance management…

  3. A High Intensity Interval Training (HIIT)-Based Running Plan Improves Athletic Performance by Improving Muscle Power.

    Science.gov (United States)

    García-Pinillos, Felipe; Cámara-Pérez, Jose C; Soto-Hermoso, Víctor M; Latorre-Román, Pedro Á

    2017-01-01

    García-Pinillos, F, Cámara-Pérez, JC, Soto-Hermoso, VM, and Latorre-Román, PÁ. A High Intensity Interval Training (HIIT)-based running plan improves athletic performance by improving muscle power. J Strength Cond Res 31(1): 146-153, 2017-This study aimed to examine the effect of a 5-week high-intensity intermittent training (HIIT)-based running plan on athletic performance and to compare the physiological and neuromuscular responses during a sprint-distance triathlon before and after the HIIT period. Thirteen triathletes were matched into 2 groups: the experimental group (EG) and the control group (CG). The CG was asked to maintain their normal training routines, whereas the EG maintained only their swimming and cycling routines and modified their running routine. Participants completed a sprint-distance triathlon before (pretest) and after (posttest) the intervention period. In both pretest and posttest, the participants performed 4 jumping tests: before the race (baseline), postswim, postcycling, and postrun. Additionally, heart rate was monitored (HRmean), whereas rate of perceived exertion (RPE) and blood lactate accumulation (BLa) were registered after the race. No significant differences (p ≥ 0.05) between groups were found before HIIT intervention (at pretest). Significant group-by-training interactions were found in vertical jumping ability and athletic performance: the EG improved jumping performance (∼6-9%, p ≤ 0.05, effect size (ES) > 0.7), swimming performance (p = 0.013, ES = 0.438), and running time (p = 0.001, ES = 0.667) during the competition, whereas the CG remained unchanged (p ≥ 0.05, ES HIIT-based running plan combined with the high training volumes of these triathletes in swimming and cycling improved athletic performance during a sprint-distance triathlon. This improvement may be due to improved neuromuscular characteristics that were transferred into improved muscle power and work economy.

  4. The urban harvest approach as framework and planning tool for improved water and resource cycles.

    Science.gov (United States)

    Leusbrock, I; Nanninga, T A; Lieberg, K; Agudelo-Vera, C M; Keesman, K J; Zeeman, G; Rijnaarts, H H M

    2015-01-01

    Water and resource availability in sufficient quantity and quality for anthropogenic needs represents one of the main challenges in the coming decades. To prepare for upcoming challenges such as increased urbanization and climate change related consequences, innovative and improved resource management concepts are indispensable. In recent years we have developed and applied the urban harvest approach (UHA). The UHA aims to model and quantify the urban water cycle on different temporal and spatial scales. This approach allowed us to quantify the impact of the implementation of water saving measures and new water treatment concepts in cities. In this paper we will introduce the UHA and its application for urban water cycles. Furthermore, we will show first results for an extension to energy cycles and highlight future research items (e.g. nutrients, water-energy-nexus).

  5. Improving operational performance by influencing shopfloor behavior via performance management practices

    NARCIS (Netherlands)

    de Leeuw, S.L.J.M.; van den Berg, J.P.

    2011-01-01

    It is generally believed that companies applying performance management practices outperform those that do not measure and manage their performance. Studies examining the link between performance management and performance improvement implicitly assume that performance management affects behavior of

  6. Performance improvement by alumina coatings on Y

    NARCIS (Netherlands)

    Zhou, Z.; Zhou, Nan; Lu, Xiangyang; ten Kate, O.M.; Valdesueiro Gonzalez, D.; van Ommen, J.R.; Hintzen, H.T.J.M.

    2016-01-01

    To improve the thermal stability, Al2O3 has been successfully coated on a Y3Al5O12:Ce3+ (YAG:Ce) phosphor powder host by using the Atomic Layer Deposition (ALD) approach in a fluidized bed reactor. Transmission Electron Microscopy

  7. Reactor coolant pump seals: improving their performance

    International Nuclear Information System (INIS)

    Pothier, N.E.; Metcalfe, R.

    1986-06-01

    Large CANDU plants are benefitting from transient-resistant four-year reliable reactor coolant pump seal lifetimes, a direct result of AECL's 20-year comprehensive seal improvement program involving R and D staff, manufacturers, and plant designers and operators. An overview of this program is presented, which covers seal modification design, testing, post-service examination, specialized maintenance and quality control. The relevancy of this technology to Light Water Reactor Coolant Pump Seals is also discussed

  8. Effect of β-alanine supplementation on 20 km cycling time trial performance

    Directory of Open Access Journals (Sweden)

    Ruth Margaret JAMES

    2014-09-01

    Full Text Available The effects of β-alanine supplementation on high-intensity cycling performance and capacity have been evaluated, although the effects on longer duration cycling performance are unclear. Nineteen UK category 1 male cyclists completed four 20 km cycling time trials, two before and two after supplementation with either 6.4 g•d-1 β-alanine (n = 10; BA or a matched placebo (n = 9; P. Performance time for the 20 km time trial and 1 km split times were recorded. There was no significant effect of β-alanine supplementation on 20 km time trial performance (BA-pre 1943 ± 129 s; BA-post 1950 ± 147 s; P-pre 1989 ± 106 s; P-post 1986 ± 115 s or on the performance of each 1 km split. The effect of β-alanine on 20 km time trial performance was deemed unclear as determined by magnitude based inferences. Supplementation with 6.4 g•d-1 of β-alanine for 4 weeks did not affect 20 km cycling time trial performance in well trained male cyclists.

  9. Improvement an enterprises marketing performance measurement system

    Directory of Open Access Journals (Sweden)

    Stanković Ljiljana

    2013-01-01

    Full Text Available Business conditions in which modern enterprises do business are more and more complex. The complexity of the business environment is caused by activities of external and internal factors, which imposes the need for the turn in management focus. One of key turns is related to the need of adaptation and development of new business performance evaluation systems. The evaluation of marketing contribution to business performance is very important however a complex task as well. The marketing theory and practice indicates the need for developing adequate standards and systems for evaluating the efficiency of marketing decisions. The better understanding of marketing standards and ways that managers use is a very important factor that affects the efficiency of strategic decision-making. The paper presents the results of researching the way in which managers perceive and apply marketing performance measures. The data that were received through the field research sample enabled the consideration of the managers' attitudes on practical ways of implementing marketing performance measurement and identifying measures that managers imply as used mostly in business practice.

  10. Does Negotiation Training Improve Negotiators' Performance?

    Science.gov (United States)

    ElShenawy, Eman

    2010-01-01

    Purpose: This paper's objective is to test the main effect of negotiation training-level on acquiring negotiation skills. Training level refers to the time a trainee spends in a negotiation training course receiving the standard style and methods of training. Negotiation skills are manifested through trainees' performance after receiving training.…

  11. Improving spelling performance and spelling consciousness

    NARCIS (Netherlands)

    Cordewener, K.A.H.; Verhoeven, L.T.W.; Bosman, A.M.T.

    2016-01-01

    This study examined the immediate and sustained effects of three training conditions on both spelling performance and spelling consciousness of 72 third-grade low- and high-skilled spellers. Spellers were assigned to a strategy-instruction, self-correction, or no-correction condition. The role of

  12. Improving Spelling Performance and Spelling Consciousness

    Science.gov (United States)

    Cordewener, Kim A. H.; Verhoeven, Ludo; Bosman, Anna M. T.

    2016-01-01

    This study examined the immediate and sustained effects of three training conditions on both spelling performance and spelling consciousness of 72 third-grade low- and high-skilled spellers. Spellers were assigned to a strategy-instruction, self-correction, or no-correction condition. The role of spelling ability and word characteristic were also…

  13. Improving Student Performance through Parent Involvement.

    Science.gov (United States)

    Steventon, Candace E.

    A personalized parenting program was implemented to address poor academic performance and low self-esteem of high school students. Student records, the Coopersmith Self-Esteem Inventory, the Behavior Evaluation Scale, and teacher surveys were employed to identify and measure academic and/or self-perception growth. Parents participated in an 8-week…

  14. Environmental performances of different configurations of a material recovery facility in a life cycle perspective.

    Science.gov (United States)

    Ardolino, Filomena; Berto, Chiara; Arena, Umberto

    2017-10-01

    The study evaluated the environmental performances of an integrated material recovery facility (MRF) able to treat 32kt/y of unsorted mixed waste, made of residuals from household source separation and separate collection. The facility includes a mechanical sorting platform for the production of a solid recovered fuel (SRF) utilized in an external waste-to-energy plant, bio-cells for tunnel composting of organic fraction, and a sanitary landfill for the safe disposal of ultimate waste. All the MRF sub-units have been analysed in depth in order to acquire reliable data for a life cycle assessment study, focused on the environmental performances of different configurations of the facility. The study investigated a "past" configuration, including just mechanical sorting, landfilling and biogas combustion in a gas engine, and the "present" one, which includes also a composting unit. Two possible "future" configurations, having a gasifier inside the MRF battery limits, have been also analysed, assessing the performances of two fluidized bed reactors of different size, able to gasify only the residues generated by the sorting platform or the whole amount of produced SRF, respectively. The analysis evaluated the contributions of each unit in the different configurations and allowed a reliable assessment of the technological evolution of the facility. The results quantified the positive effect of the inclusion of an aerobic treatment of the waste organic fraction. The SRF gasification in situ appears to improve the MRF environmental performances in all the impact categories, with the exclusion of that of global warming. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Improving fatigue performance of rail thermite welds

    Science.gov (United States)

    Jezzini-Aouad, M.; Flahaut, P.; Hariri, S.; Winiar, L.

    2010-06-01

    Rail transport development offers economic and ecological interests. Nevertheless, it requires heavy investments in rolling material and infrastructure. To be competitive, this transportation means must rely on safe and reliable infrastructure, which requires optimization of all implemented techniques and structure. Rail thermite (or aluminothermic) welding is widely used within the railway industry for in-track welding during re-rail and defect replacement. The process provides numerous advantages against other welding technology commonly used. Obviously, future demands on train traffic are heavier axle loads, higher train speeds and increased traffic density. Thus, a new enhanced weld should be developed to prevent accidents due to fracture of welds and to lower maintenance costs. In order to improve such assembly process, a detailed metallurgical study coupled to a thermomechanical modelling of the phenomena involved in the thermite welding process is carried out. Obtained data enables us to develop a new improved thermite weld (type A). This joint is made by modifying the routinely specified procedure (type B) used in a railway rail by a standard gap alumino-thermic weld. Joints of type A and B are tested and compared. Based on experimental temperature measurements, a finite element analysis is used to calculate the thermal residual stresses induced. In the vicinity of the weld, the residual stress patterns depend on the thermal conditions during welding as it also shown by litterature [1, 2]. In parallel, X-Ray diffraction has been used to map the residual stress field that is generated in welded rail of types A and B. Their effect on fatigue crack growth in rail welds is studied. An experimental study based on fatigue tests of rails welded by conventional and improved processes adjudicates on the new advances and results will be shown.

  16. Improving Team Performance: Proceedings of the Rand Team Performance Workshop.

    Science.gov (United States)

    1980-08-01

    Gene Gloye of ONR said at that time that by highlighting specific content areas for attention, one runs the risk of supporting "research by the yard...Meister The purpose of this paper is to describe how human factors engineering ( HFE ) relates to team performance. HFE is the application of...behavioral principles and data to the design and development of man-machine systems (MMS). HFE activities begin in the very early planning stages of MMS

  17. Benchmark and Continuous Improvement of Performance

    Directory of Open Access Journals (Sweden)

    Alina Alecse Stanciu

    2017-12-01

    Full Text Available The present Economic Environment is challenge us to perform, to think and re-think our personal strategies in according with our entities strategies, even if we are simply employed or we are entrepreneurs. Is an environment characterised by Volatility, Uncertainity, Complexity and Ambiguity - a VUCA World in which the entities must fight for their position gained in the market, disrupt new markets and new economies, developing their client portofolio, with the Performance as one final goal. The pressure of driving forces known as the 2030 Megatrends: Globalization 2.0, Environmental Crisis and the Scarcity of Resources, Individualism and Value Pluralism, Demographic Change, This paper examines whether using benchmark is an opportunity to increase the competitiveness of Romanian SMEs and the results show that benchmark is therefore a powerful instrument, combining reduced negative impact on the environment with a positive impact on the economy and society.

  18. Combined Life Cycle Assessment and Life Cycle Costing in the Eco-Care-Matrix: A case study on the performance of a modernized manufacturing system for glass containers

    DEFF Research Database (Denmark)

    Auer, Johannes; Bey, Niki; Schäfer, Johannes-Marius

    2017-01-01

    Cycle Assessment, as well as Life Cycle Costing (LCC). The results were then to be displayed in an Eco-Care-Matrix (ECM) in order to quantitatively visualize the improvements when comparing the updated manufacturing system to the previous one and they were to be discussed in terms of (i) ecodesign...

  19. A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement.

    Science.gov (United States)

    Yin, Chieh; Hsueh, Ya-Hsin; Yeh, Chun-Yu; Lo, Hsin-Chang; Lan, Yi-Ting

    2016-01-01

    Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS), which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI) between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p = 0.046) and in force plate the stand balance has also improved by 0.29 (p = 0.031); thus both methods show the significant difference.

  20. A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement

    Directory of Open Access Journals (Sweden)

    Chieh Yin

    2016-01-01

    Full Text Available Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS, which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p=0.046 and in force plate the stand balance has also improved by 0.29 (p=0.031; thus both methods show the significant difference.

  1. Does School Choice Improve Student Performance?

    OpenAIRE

    Kaja Høiseth Brugård

    2013-01-01

    This paper studies the relationship between school choice and student performance for high school students in Norway. The analysis exploits both the fact that the degree of school choice formally differs between counties, and detailed information on travelling distances to high schools, which more closely reflects the students' actual school choice possibilities. Information on students' residence, high school location, and the degree of formal school choice is used to estimate the effect on ...

  2. Performance analysis of hybrid solid oxide fuel cell and gas turbine cycle: Application of alternative fuels

    International Nuclear Information System (INIS)

    Zabihian, Farshid; Fung, Alan S.

    2013-01-01

    Highlights: • Variation of the stream properties in the syngas-fueled hybrid SOFC–GT cycle. • Detailed analysis of the operation of the methane-fueled SOFC–GT cycle. • Investigate effects of inlet fuel type and composition on performance of cycle. • Comparison of system operation when operated with and without anode recirculation. - Abstract: In this paper, the hybrid solid oxide fuel cell (SOFC) and gas turbine (GT) model was applied to investigate the effects of the inlet fuel type and composition on the performance of the cycle. This type of analysis is vital for the real world utilization of manufactured fuels in the hybrid SOFC–GT system due to the fact that these fuel compositions depends on the type of material that is processed, the fuel production process, and process control parameters. In the first part of this paper, it is shown that the results of a limited number of studies on the utilization of non-conventional fuels have been published in the open literature. However, further studies are required in this area to investigate all aspects of the issue for different configurations and assumptions. Then, the results of the simulation of the syngas-fueled hybrid SOFC–GT cycle are employed to explain the variation of the stream properties throughout the cycle. This analysis can be very helpful in understanding cycle internal working and can provide some interesting insights to the system operation. Then, the detailed information of the operation of the methane-fueled SOFC–GT cycle is presented. For both syngas- and methane-fueled cycles, the operating conditions of the equipment are presented and compared. Moreover, the comparison of the characteristics of the system when it is operated with two different schemes to provide the required steam for the cycle, with anode recirculation and with an external source of water, provides some interesting insights to the system operation. For instance, it was shown that although the physical

  3. Two cycles of plasma rich in growth factors (PRGF-Endoret) intra-articular injections improve stiffness and activities of daily living but not pain compared to one cycle on patients with symptomatic knee osteoarthritis.

    Science.gov (United States)

    Vaquerizo, Víctor; Padilla, Sabino; Aguirre, José Javier; Begoña, Leire; Orive, Gorka; Anitua, Eduardo

    2017-05-19

    To assess the clinical efficacy and safety of a treatment based on one cycle versus two cycles of intra-articular injections of plasma rich in growth factors (PRGF-Endoret) on patients with knee osteoarthritis (OA). Ninety patients with knee OA were included and evaluated. A total of 48 patients received one cycle (OC group) (3 injections on a weekly basis), while 42 patients received two cycles of PRGF-Endoret (TC group) spaced 6 months between them. Patients were evaluated with LEQUESNE and WOMAC scores before treatment and after 48 weeks. Safety assessment was also performed. A significant reduction of all assessed outcome measures was shown for both groups at 48 weeks compared with baseline values (P PRGF did not show a significantly higher pain reduction compared with one cycle treatment. However, two cycles of PRGF showed a significant improvement in WOMAC stiffness, LEQUESNE MCD, LEQUESNE ADV and LEQUESNE global subscales. Therefore, patients treated with two cycles present an improvement in quality of life. II.

  4. Improving performance by anchoring movement and "nerves".

    Science.gov (United States)

    Iso-Ahola, Seppo E; Dotson, Charles O; Jagodinsky, Adam E; Clark, Lily C; Smallwood, Lorraine L; Wilburn, Christopher; Weimar, Wendi H; Miller, Matthew W

    2016-10-01

    Golf's governing bodies' recent decision to ban all putting styles "anchoring one end of the club against the body" bridges an important practical problem with psychological theory. We report the first experiment testing whether anchoring provides technical and/or psychological advantage in competitive performance. Many "greats" of professional golf from Arnold Palmer and Jack Nicklaus to Tiger Woods have argued against anchoring, believing that it takes "nerves" out of competitive performance and therefore artificially levels the playing field. To shed more light on the issue, we tested participants' performance with anchored and unanchored putters under low and high pressure when controlling for the putter length. We found no statistically significant evidence for a technical advantage due to anchoring but a clear psychological advantage: participants who anchored their putters significantly outperformed unanchored counterparts under high, but not low, pressure. Results provide tentative evidence for the ban's justification from a competitive standpoint. However, before any definite conclusions can be made, more research is needed when using high-level golfers. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Performance assessment modeling of high level nuclear wasteforms from the pyroprocess fuel cycle

    International Nuclear Information System (INIS)

    Nutt, W.M.; Hill, R.N.; Bullen, D.B.

    1995-01-01

    Several performance assessment (PA) analyses have been completed to estimate the release to the accessible environment of radionuclides from spent light water reactor (LWR) fuel emplaced in the proposed Yucca Mountain repository. Probabilistic methods were utilized based on the complexity of the repository system. Recent investigations have been conducted to identify the merits of a pyroprocess fuel cycle. This cycle utilizes high temperature molten salts and metals to partially separate actinides and fission products. In a closed liquid metal reactor (LMR) fuel cycle, this allows recycling of nearly all of the actinides. In a once-through cycle, this isolates the actinides for storage into a wasteform which can be specifically tailored for their retention. With appropriate front-end treatment, this Process can also be used to treat LWR spent fuel

  6. Performance of the FFTF heat transport system during cycles 1 and 2

    International Nuclear Information System (INIS)

    Burke, T.M.; Yunker, W.H.; Cramer, E.R.

    1983-01-01

    From April 1982 through May 1983, the Fast Flux Test Facility (FFTF) completed its first two full cycles of operation. This experience has provided significant information relative to the performance of the Main Heat Transport System (MHTS). While in general, the MHTS performance has been extremely good, there have been a few unanticipated events and trends which could very well influence the design and/or operation of further LMFBR plants. The performance of the major MHTS components is discussed

  7. Duty cycle testing and performance evaluation of the SM-229 teleoperator

    International Nuclear Information System (INIS)

    Stoughton, R.S.; Kuban, D.P.

    1985-11-01

    This paper contains the first known experimental studies and analyses of teleoperator performance for specific duty cycles. The results are presented in two distinct areas as position usage patterns, and as three-dimensional power grids. The position usage patterns are a valuable means to assess the available motion range. The power grids are a unique concept for evaluating joint performance. Final conclusions contain recommendations to upgrade the teleoperator for optimum performance. 3 refs., 16 figs

  8. Thermo-Economic Performance Analysis of a Regenerative Superheating Organic Rankine Cycle for Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Zhonghe Han

    2017-10-01

    Full Text Available The Organic Rankine Cycle (ORC is a promising form of technology for recovering low-grade waste heat. In this study, a regenerative ORC system is established to recover the waste flue gas of 160 °C. Focusing on thermodynamic and economic performance while simultaneously considering the limitations of volume flow ratio (VFR and the effect of superheat, working fluid selection and parameter optimization have been investigated. The optimization of the evaporation temperature is carried out by analyzing the variation of net power output and specific investment cost (SIC. Then, the net power output, specific net power output, total exergy destruction rate, VFR, total capital cost, and levelized electricity cost (LEC are selected as criteria, and a fuzzy multi-criteria evaluation method is adopted to select a more suitable working fluid and determine the optimal degree of superheat. In addition, the preheating coefficient, latent heat coefficient, superheating coefficient, and internal heat coefficient were proposed to explore the effect of working fluid critical temperature on thermal efficiency. Research studies demonstrate that there is an optimal evaporation temperature, maximizing net power output and minimizing the SIC. Isohexane and butane have greater specific net power output due to greater latent heat. A suitable degree of superheat is not only conducive to improving the working capacity of working fluids, but also reduces the VFR, total capital cost, SIC, and LEC for different working fluids. Thus, the system’s thermodynamic and economic performance—as well as the operational stability—are improved. Among the six working fluids, butane exhibits the best comprehensive performance, and its optimal evaporation temperature and degree of superheat are 100 °C and 5 °C, respectively.

  9. Nuclear steam power plant cycle performance calculations supported by power plant monitoring and results computer

    International Nuclear Information System (INIS)

    Bettes, R.S.

    1984-01-01

    The paper discusses the real time performance calculations for the turbine cycle and reactor and steam generators of a nuclear power plant. Program accepts plant measurements and calculates performance and efficiency of each part of the cycle: reactor and steam generators, turbines, feedwater heaters, condenser, circulating water system, feed pump turbines, cooling towers. Presently, the calculations involve: 500 inputs, 2400 separate calculations, 500 steam properties subroutine calls, 200 support function accesses, 1500 output valves. The program operates in a real time system at regular intervals

  10. Hybrid Modeling Improves Health and Performance Monitoring

    Science.gov (United States)

    2007-01-01

    Scientific Monitoring Inc. was awarded a Phase I Small Business Innovation Research (SBIR) project by NASA's Dryden Flight Research Center to create a new, simplified health-monitoring approach for flight vehicles and flight equipment. The project developed a hybrid physical model concept that provided a structured approach to simplifying complex design models for use in health monitoring, allowing the output or performance of the equipment to be compared to what the design models predicted, so that deterioration or impending failure could be detected before there would be an impact on the equipment's operational capability. Based on the original modeling technology, Scientific Monitoring released I-Trend, a commercial health- and performance-monitoring software product named for its intelligent trending, diagnostics, and prognostics capabilities, as part of the company's complete ICEMS (Intelligent Condition-based Equipment Management System) suite of monitoring and advanced alerting software. I-Trend uses the hybrid physical model to better characterize the nature of health or performance alarms that result in "no fault found" false alarms. Additionally, the use of physical principles helps I-Trend identify problems sooner. I-Trend technology is currently in use in several commercial aviation programs, and the U.S. Air Force recently tapped Scientific Monitoring to develop next-generation engine health-management software for monitoring its fleet of jet engines. Scientific Monitoring has continued the original NASA work, this time under a Phase III SBIR contract with a joint NASA-Pratt & Whitney aviation security program on propulsion-controlled aircraft under missile-damaged aircraft conditions.

  11. Performance of ammonia–water based cycles for power generation from low enthalpy heat sources

    International Nuclear Information System (INIS)

    Mergner, Hanna; Weimer, Thomas

    2015-01-01

    Cost efficient power generation from low temperature heat sources requires an optimal usage of the available heat. In addition to the ORC (Organic Rankine Cycles), cycles with ammonia and water as working fluid show promising results regarding efficiency. Due to their non-isothermal phase change, mixtures can adapt well to a liquid heat source temperature profile and reduce the exergetic losses. In this analysis thermodynamic calculations on the layouts of two existing ammonia–water cycles are compared: a geothermal power plant based on a Siemens’ patent and a modified lab plant based on a patent invented by Kalina (KCS-34). The difference between the two cycles is the position of the internal heat recovery. Cycle simulations were carried out at defined boundary conditions in order to identify optimal operation parameters. For the selected heat source of 393.15 K (hot water) the ammonia mass fraction between 80% and 90% results in the best performance in both configurations. In general, the layout of Siemens achieves a slightly better efficiency compared to the KCS-34. Compared to an ORC using R245fa as working fluid, the exergetic efficiency can be increased by the ammonia/water based cycles by approximately 25%. - Highlights: • Two NH 3 /H 2 O based cycles based on existing plants are analyzed and compared. • A simple KCS-34 focuses on a high enthalpy difference at the turbine. • The Kalina cycle of a Siemens patent KC SG1 runs on a high vapor mass flow. • The layout of the KC SG1 shows slightly better results compared to the KCS-34. • NH 3 /H 2 O cycles show an efficiency increase compared to a regular ORC with R245fa

  12. Hypothesis driven drug design: improving quality and effectiveness of the design-make-test-analyse cycle.

    Science.gov (United States)

    Plowright, Alleyn T; Johnstone, Craig; Kihlberg, Jan; Pettersson, Jonas; Robb, Graeme; Thompson, Richard A

    2012-01-01

    In drug discovery, the central process of constructing and testing hypotheses, carefully conducting experiments and analysing the associated data for new findings and information is known as the design-make-test-analyse cycle. Each step relies heavily on the inputs and outputs of the other three components. In this article we report our efforts to improve and integrate all parts to enable smooth and rapid flow of high quality ideas. Key improvements include enhancing multi-disciplinary input into 'Design', increasing the use of knowledge and reducing cycle times in 'Make', providing parallel sets of relevant data within ten working days in 'Test' and maximising the learning in 'Analyse'. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Mental Toughness Moderates Social Loafing in Cycle Time-Trial Performance.

    Science.gov (United States)

    Haugen, Tommy; Reinboth, Michael; Hetlelid, Ken J; Peters, Derek M; Høigaard, Rune

    2016-09-01

    The purpose of this study was to determine if mental toughness moderated the occurrence of social loafing in cycle time-trial performance. Twenty-seven men (Mage = 17.7 years, SD = 0.6) completed the Sport Mental Toughness Questionnaire prior to completing a 1-min cycling trial under 2 conditions: once with individual performance identified, and once in a group with individual performance not identified. Using a median split of the mental toughness index, participants were divided into high and low mental toughness groups. Cycling distance was compared using a 2 (trial) × 2 (high-low mental toughness) analysis of variance. We hypothesized that mentally tough participants would perform equally well under both conditions (i.e., no indication of social loafing) compared with low mentally tough participants, who would perform less well when their individual performance was not identifiable (i.e., demonstrating the anticipated social loafing effect). The high mental toughness group demonstrated consistent performance across both conditions, while the low mental toughness group reduced their effort in the non-individually identifiable team condition. The results confirm that (a) clearly identifying individual effort/performance is an important situational variable that may impact team performance and (b) higher perceived mental toughness has the ability to negate the tendency to loaf.

  14. Continuing education for performance improvement: a creative approach.

    Science.gov (United States)

    Collins, Patti-Ann; Hardesty, Ilana; White, Julie L; Zisblatt, Lara

    2012-10-01

    In an effort to improve patient safety and health care outcomes, continuing medical education has begun to focus on performance improvement initiatives for physician practices. Boston University School of Medicine's (BUSM) Continuing Nursing Education Accredited Provider Unit has begun a creative project to award nursing contact hours for nurses' participation in performance improvement activities. This column highlights its initial efforts. Copyright 2012, SLACK Incorporated.

  15. Improving Steam System Performance: A Sourcebook for Industry, Second Edition

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-02-23

    This sourcebook is designed to provide steam system users with a reference that describes the basic steam system components, outlines opportunities for energy and performance improvements, and discusses the benefits of a systems approach in identifying and implementing these improvement opportunities. The sourcebook is divided into three main sections: steam system basics, performance improvement opportunities, and where to find help.

  16. A performance improvement plan to increase nurse adherence to use of medication safety software.

    Science.gov (United States)

    Gavriloff, Carrie

    2012-08-01

    Nurses can protect patients receiving intravenous (IV) medication by using medication safety software to program "smart" pumps to administer IV medications. After a patient safety event identified inconsistent use of medication safety software by nurses, a performance improvement team implemented the Deming Cycle performance improvement methodology. The combined use of improved direct care nurse communication, programming strategies, staff education, medication safety champions, adherence monitoring, and technology acquisition resulted in a statistically significant (p < .001) increase in nurse adherence to using medication safety software from 28% to above 85%, exceeding national benchmark adherence rates (Cohen, Cooke, Husch & Woodley, 2007; Carefusion, 2011). Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance.

    Science.gov (United States)

    Glaister, Mark; Pattison, John R; Muniz-Pumares, Daniel; Patterson, Stephen D; Foley, Paul

    2015-01-01

    The aim of this study was to examine the acute supplementation effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance. Using a randomized, counterbalanced, double-blind Latin-square design, 14 competitive female cyclists (age: 31 ± 7 years; height: 1.69 ± 0.07 m; body mass: 61.6 ± 6.0 kg) completed four 20-km time trials on a racing bicycle fitted to a turbo trainer. Approximately 2.5 hours before each trial, subjects consumed a 70-ml dose of concentrated beetroot juice containing either 0.45 g of dietary nitrate or with the nitrate content removed (placebo). One hour before each trial, subjects consumed a capsule containing either 5 mg·kg of caffeine or maltodextrin (placebo). There was a significant effect of supplementation on power output (p = 0.001), with post hoc tests revealing higher power outputs in caffeine (205 ± 21 W) vs. nitrate (194 ± 22 W) and placebo (194 ± 25 W) trials only. Caffeine-induced improvements in power output corresponded with significantly higher measures of heart rate (caffeine: 166 ± 12 b·min vs. placebo: 159 ± 15 b·min; p = 0.02), blood lactate (caffeine: 6.54 ± 2.40 mmol·L vs. placebo: 4.50 ± 2.11 mmol·L; p caffeine: 0.95 ± 0.04 vs. placebo: 0.91 ± 0.05; p = 0.03). There were no effects (p ≥ 0.05) of supplementation on cycling cadence, rating of perceived exertion, (Equation is included in full-text article.), or integrated electromyographic activity. The results of this study support the well-established beneficial effects of caffeine supplementation on endurance performance. In contrast, acute supplementation with dietary nitrate seems to have no effect on endurance performance and adds nothing to the benefits afforded by caffeine supplementation.

  18. An improved technology for decontaminating ruthenium in uranium purification cycle by hydroxylamine pretreatment

    International Nuclear Information System (INIS)

    Qi Zhanshun; Zhu Zhixuan; Zhang Pilu

    1996-01-01

    The Influences of hydroxylamine concentration, pretreatment time, acidity and the concentration of stabilizer have been studied, and the best pretreatment condition for the improvement of Ru decontamination in uranium purification cycle by hydroxylamine pretreatment has been obtained. The results show that no satisfactory result can be obtained by solely using hydroxylamine as pretreatment agent unless a small amount of hydrazine is added into the pretreatment system as stabilizer

  19. Project Management Life Cycle Models to Improve Management in High-rise Construction

    Science.gov (United States)

    Burmistrov, Andrey; Siniavina, Maria; Iliashenko, Oksana

    2018-03-01

    The paper describes a possibility to improve project management in high-rise buildings construction through the use of various Project Management Life Cycle Models (PMLC models) based on traditional and agile project management approaches. Moreover, the paper describes, how the split the whole large-scale project to the "project chain" will create the factor for better manageability of the large-scale buildings project and increase the efficiency of the activities of all participants in such projects.

  20. Project Management Life Cycle Models to Improve Management in High-rise Construction

    Directory of Open Access Journals (Sweden)

    Burmistrov Andrey

    2018-01-01

    Full Text Available The paper describes a possibility to improve project management in high-rise buildings construction through the use of various Project Management Life Cycle Models (PMLC models based on traditional and agile project management approaches. Moreover, the paper describes, how the split the whole large-scale project to the "project chain" will create the factor for better manageability of the large-scale buildings project and increase the efficiency of the activities of all participants in such projects.

  1. Effect of time of day on performance, hormonal and metabolic response during a 1000-M cycling time trial.

    Directory of Open Access Journals (Sweden)

    Alan Lins Fernandes

    Full Text Available The aim of this study was to determine the effect of time of day on performance, pacing, and hormonal and metabolic responses during a 1000-m cycling time-trial. Nine male, recreational cyclists visited the laboratory four times. During the 1st visit the participants performed an incremental test and during the 2nd visit they performed a 1000-m cycling familiarization trial. On the 3rd and 4th visits, the participants performed a 1000-m TT at either 8 am or 6 pm, in randomized, repeated-measures, crossover design. The time to complete the time trial was lower in the evening than in the morning (88.2±8.7 versus 94.7±10.9 s, respectively, p0.05, but the norepinephrine response to the exercise was increased in the morning (+46%, p0.05. Our findings suggest that performance was improved in the evening, and it was accompanied by an improved hormonal and metabolic milieu.

  2. Improvement actions in waste management systems at the provincial scale based on a life cycle assessment evaluation.

    Science.gov (United States)

    Rigamonti, L; Falbo, A; Grosso, M

    2013-11-01

    This paper reports some of the findings of the 'GERLA' project: GEstione Rifiuti in Lombardia - Analisi del ciclo di vita (Waste management in Lombardia - Life cycle assessment). The project was devoted to support Lombardia Region in the drafting of the new waste management plan by applying a life cycle thinking perspective. The present paper mainly focuses on four Provinces in the Region, which were selected based on their peculiarities. Life cycle assessment (LCA) was adopted as the methodology to assess the current performance of the integrated waste management systems, to discuss strengths and weaknesses of each of them and to design their perspective evolution as of year 2020. Results show that despite a usual business approach that is beneficial to all the provinces, the introduction of technological and management improvements to the system provides in general additional energy and environmental benefits for all four provinces. The same improvements can be easily extended to the whole Region, leading to increased environmental benefits from the waste management sector, in line with the targets set by the European Union for 2020. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. HTR-Based Power Plants’ Performance Analysis Applied on Conventional Combined Cycles

    Directory of Open Access Journals (Sweden)

    José Carbia Carril

    2015-01-01

    Full Text Available In high temperature reactors including gas cooled fast reactors and gas turbine modular helium reactors (GT-MHR specifically designed to operate as power plant heat sources, efficiency enhancement at effective cost under safe conditions can be achieved. Mentioned improvements concern the implementation of two cycle structures: (a, a stand alone Brayton operating with helium and a stand alone Rankine cycle (RC with regeneration, operating with carbon dioxide at ultrasupercritical pressure as working fluid (WF, where condensation is carried out at quasicritical conditions, and (b, a combined cycle (CC, in which the topping closed Brayton cycle (CBC operates with helium as WF, while the bottoming RC is operated with one of the following WFs: carbon dioxide, xenon, ethane, ammonia, or water. In both cases, an intermediate heat exchanger (IHE is proposed to provide thermal energy to the closed Brayton or to the Rankine cycles. The results of the case study show that the thermal efficiency, through the use of a CC, is slightly improved (from 45.79% for BC and from 50.17% for RC to 53.63 for the proposed CC with He-H2O operating under safety standards.

  4. The improvement of performances for PWR fuels

    International Nuclear Information System (INIS)

    Debes

    2001-01-01

    UO 2 fuels used in French nuclear power plants are authorized for values of burn-ups up to 52 GWj/t. Constant technological progress concerning pellets, cladding, and the design of the assembly has led to better performance and a broader safety margin. EDF is gathering all the elements to qualify and back its demand to increase the limit burn-up to 65 GWj/t in 2004 and to 70 GWj/t in 2008. For the same amount of energy produced, this policy of higher burn-ups will allow: - a reduction of the number of spent fuel assemblies, - a direct economic spare by using less fuel assemblies, - a reduction of personnel dosimetry because of longer irradiation campaigns, and - less quantity of residual plutonium produced. (A.C.)

  5. Improved Performance in Mammalian Cell Perfusion Cultures by Growth Inhibition.

    Science.gov (United States)

    Wolf, Moritz K F; Closet, Aurélie; Bzowska, Monika; Bielser, Jean-Marc; Souquet, Jonathan; Broly, Hervé; Morbidelli, Massimo

    2018-05-21

    Mammalian cell perfusion cultures represent a promising alternative to the current fed-batch technology for the production of various biopharmaceuticals. Long-term operation at a fixed viable cell density (VCD) requires a viable culture and a constant removal of excessive cells. Product loss in the cell removing bleed stream deteriorates the process yield. In this study, the authors investigate the use of chemical and environmental growth inhibition on culture performance by either adding valeric acid (VA) to the production media or by reducing the culture temperature (33.0 °C) with respect to control conditions (36.5 °C, no VA). Low temperature significantly reduces cellular growth, thus, resulting in lower bleed rates accompanied by a reduced product loss of 11% compared to 26% under control conditions. Additionally, the cell specific productivity of the target protein improves and maintained stable leading to media savings per mass of product. VA shows initially an inhibitory effect on cellular growth. However, cells seemed to adapt to the presence of the inhibitor resulting in a recovery of the cellular growth. Cell cycle and Western blot analyses support the observed results. This work underlines the role of temperature as a key operating variable for the optimization of perfusion cultures. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Theoretical Model for the Performance of Liquid Ring Pump Based on the Actual Operating Cycle

    Directory of Open Access Journals (Sweden)

    Si Huang

    2017-01-01

    Full Text Available Liquid ring pump is widely applied in many industry fields due to the advantages of isothermal compression process, simple structure, and liquid-sealing. Based on the actual operating cycle of “suction-compression-discharge-expansion,” a universal theoretical model for performance of liquid ring pump was established in this study, to solve the problem that the theoretical models deviated from the actual performance in operating cycle. With the major geometric parameters and operating conditions of a liquid ring pump, the performance parameters such as the actual capacity for suction and discharge, shaft power, and global efficiency can be conveniently predicted by the proposed theoretical model, without the limitation of empiric range, performance data, or the detailed 3D geometry of pumps. The proposed theoretical model was verified by experimental performances of liquid ring pumps and could provide a feasible tool for the application of liquid ring pump.

  7. Improving UV Resistance of High Performance Fibers

    Science.gov (United States)

    Hassanin, Ahmed

    High performance fibers are characterized by their superior properties compared to the traditional textile fibers. High strength fibers have high modules, high strength to weight ratio, high chemical resistance, and usually high temperature resistance. It is used in application where superior properties are needed such as bulletproof vests, ropes and cables, cut resistant products, load tendons for giant scientific balloons, fishing rods, tennis racket strings, parachute cords, adhesives and sealants, protective apparel and tire cords. Unfortunately, Ultraviolet (UV) radiation causes serious degradation to the most of high performance fibers. UV lights, either natural or artificial, cause organic compounds to decompose and degrade, because the energy of the photons of UV light is high enough to break chemical bonds causing chain scission. This work is aiming at achieving maximum protection of high performance fibers using sheathing approaches. The sheaths proposed are of lightweight to maintain the advantage of the high performance fiber that is the high strength to weight ratio. This study involves developing three different types of sheathing. The product of interest that need be protected from UV is braid from PBO. First approach is extruding a sheath from Low Density Polyethylene (LDPE) loaded with different rutile TiO2 % nanoparticles around the braid from the PBO. The results of this approach showed that LDPE sheath loaded with 10% TiO2 by weight achieved the highest protection compare to 0% and 5% TiO2. The protection here is judged by strength loss of PBO. This trend noticed in different weathering environments, where the sheathed samples were exposed to UV-VIS radiations in different weatheromter equipments as well as exposure to high altitude environment using NASA BRDL balloon. The second approach is focusing in developing a protective porous membrane from polyurethane loaded with rutile TiO2 nanoparticles. Membrane from polyurethane loaded with 4

  8. FES-assisted Cycling Improves Aerobic Capacity and Locomotor Function Postcerebrovascular Accident.

    Science.gov (United States)

    Aaron, Stacey E; Vanderwerker, Catherine J; Embry, Aaron E; Newton, Jennifer H; Lee, Samuel C K; Gregory, Chris M

    2018-03-01

    After a cerebrovascular accident (CVA) aerobic deconditioning contributes to diminished physical function. Functional electrical stimulation (FES)-assisted cycling is a promising exercise paradigm designed to target both aerobic capacity and locomotor function. This pilot study aimed to evaluate the effects of an FES-assisted cycling intervention on aerobic capacity and locomotor function in individuals post-CVA. Eleven individuals with chronic (>6 months) post-CVA hemiparesis completed an 8-wk (three times per week; 24 sessions) progressive FES-assisted cycling intervention. V˙O2peak, self-selected, and fastest comfortable walking speeds, gait, and pedaling symmetry, 6-min walk test (6MWT), balance, dynamic gait movements, and health status were measured at baseline and posttraining. Functional electrical stimulation-assisted cycling significantly improved V˙O2peak (12%, P = 0.006), self-selected walking speed (SSWS, 0.05 ± 0.1 m·s, P = 0.04), Activities-specific Balance Confidence scale score (12.75 ± 17.4, P = 0.04), Berg Balance Scale score (3.91 ± 4.2, P = 0.016), Dynamic Gait Index score (1.64 ± 1.4, P = 0.016), and Stroke Impact Scale participation/role domain score (12.74 ± 16.7, P = 0.027). Additionally, pedal symmetry, represented by the paretic limb contribution to pedaling (paretic pedaling ratio [PPR]) significantly improved (10.09% ± 9.0%, P = 0.016). Although step length symmetry (paretic step ratio [PSR]) did improve, these changes were not statistically significant (-0.05% ± 0.1%, P = 0.09). Exploratory correlations showed moderate association between change in SSWS and 6-min walk test (r = 0.74), and moderate/strong negative association between change in PPR and PSR. These results support FES-assisted cycling as a means to improve both aerobic capacity and locomotor function. Improvements in SSWS, balance, dynamic walking movements, and participation in familial and societal roles are important targets for rehabilitation of individuals

  9. Improving the performance of LOX/kerosene upper stage rocket engines

    Directory of Open Access Journals (Sweden)

    IgorN. Nikischenko

    2017-09-01

    Full Text Available Improved liquid rocket engine cycles were proposed and analyzed via comparison with existing staged combustion and gas-generator cycles. The key features of the proposed cycles are regenerative cooling of thrust chamber by oxygen and subsequent use of this oxygen for driving one or two oxygen pumps. The fuel pump(s are driven in a conventional manner, for example, using a fuel-rich gas-generator cycle. Comparison with staged combustion cycle based on oxygen-rich pre-burner showed that one of the proposed semi-expander cycles has a specific impulse only on 0.4% lower while providing much lower oxygen temperature, more efficient tank pressurizing system and built-in roll control. This semi-expander cycle can be considered as a more reliable and cost-effective alternative of staged combustion cycle. Another semi-expander cycle can be considered as an improvement of gas-generator cycle. All proposed semi-expander cycles were developed as a derivative of thrust chamber regenerative cooling performed by oxygen. Analysis of existing oxygen/kerosene engines showed that replacing of kerosene regenerative cooling with oxygen allows a significant increase of achievable specific impulse, via optimization of mixture ratio. It is especially the case for upper stage engines. The increasing of propellants average density can be considered as an additional benefit of mixture ratio optimization. It was demonstrated that oxygen regenerative cooling of thrust chamber is a feasible and the most promising option for oxygen/kerosene engines. Combination of oxygen regenerative cooling and semi-expander cycles potentially allows creating the oxygen/kerosene propulsion systems with minimum specific impulse losses. It is important that such propulsion systems can be fully based on inherited and well-proven technical solutions. A hypothetic upper stage engine with thrust 19.6 kN was chosen as a prospective candidate for theoretical analysis of the proposed semi

  10. Efficacy of a Template Creation Approach for Performance Improvement

    Science.gov (United States)

    Lyons, Paul R.

    2011-01-01

    This article presents the training and performance improvement approach, performance templates (P-T), and provides empirical evidence to support the efficacy of P-T. This approach involves a partnership among managers, trainers, and employees in the creation, use, and improvement of guides to affect the performance of critical tasks in the…

  11. Oral Presence of Carbohydrate and Caffeine in Chewing Gum: Independent and Combined Effects on Endurance Cycling Performance.

    Science.gov (United States)

    Oberlin-Brown, Katherine T; Siegel, Rodney; Kilding, Andrew E; Laursen, Paul B

    2016-03-01

    The oral presence of carbohydrate (CHO) and caffeine (CAF) may independently enhance exercise performance, but their influence on performance during prolonged exercise is less known. To determine the independent and combined effects of CHO and CAF administered in chewing gum during a cycling time trial (TT) after prolonged exercise. Eleven male cyclists (32.2 ± 7.5 y, 74.3 ± 6.8 kg, 60.2 ± 4.0 mL · kg-1 · min-1 VO2peak) performed 4 experimental trials consisting of 90-min constant-load cycling at 80% of their second ventilatory threshold (207 ± 30 W), followed immediately by a 20-km TT. Under double-blinded conditions, cyclists received placebo (PLA), CHO, CAF, or a combined CHO+CAF chewing gum at 0-, 5-, 10-, and 15-km points of the TT. Overall TT performance was similar across experimental and PLA trials (%mean difference ± 90%CL 0.2% ± 2.0%, 0.4% ± 2.2%, 0.1% ± 1.8% for CHO, CAF, and CHO+CAF). Compared with PLA, mean power output tended to be higher in the first 2 quarters of the TT with CHO (1.6% ± 3.1% and 0.8% ± 2.0%) and was substantially improved in the last 2 quarters during CAF and CHO+CAF trials (4.2% ± 3.0% and 2.0% ± 1.8%). There were no differences in average heart rate (ES performance. Blood lactate was substantially higher post-TT for CAF and CHO+CAF (ES >0.6). After prolonged constant-load cycling, the oral presence of CHO and CAF in chewing gum, independently or in combination, did not improve overall performance but did influence pacing.

  12. Considerations on the Assessment and Use of Cycling Performance Metrics and their Integration in the Athlete's Biological Passport

    Directory of Open Access Journals (Sweden)

    Paolo Menaspà

    2017-11-01

    Full Text Available Over the past few decades the possibility to capture real-time data from road cyclists has drastically improved. Given the increasing pressure for improved transparency and openness, there has been an increase in publication of cyclists' physiological and performance data. Recently, it has been suggested that the use of such performance biometrics may be used to strengthen the sensitivity and applicability of the Athlete Biological Passport (ABP and aid in the fight against doping. This is an interesting concept which has merit, although there are several important factors that need to be considered. These factors include accuracy of the data collected and validity (and reliability of the subsequent performance modeling. In order to guarantee high quality standards, the implementation of well-structured Quality-Systems within sporting organizations should be considered, and external certifications may be required. Various modeling techniques have been developed, many of which are based on fundamental intensity/time relationships. These models have increased our understanding of performance but are currently limited in their application, for example due to the largely unaccounted effects of environmental factors such as, heat and altitude. In conclusion, in order to use power data as a performance biometric to be integrated in the biological passport, a number of actions must be taken to ensure accuracy of the data and better understand road cycling performance in the field. This article aims to outline considerations in the quantification of cycling performance, also presenting an alternative method (i.e., monitoring race results to allow for determination of unusual performance improvements.

  13. Study on optimal performance and working temperatures of endoreversible forward and reverse Carnot cycles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.Z.; Sun, F.R.; Cheng, S.M.; Chen, L.G. [Huazhong Univ. of Sceince and Technology, Wuhan (China). Dept. of Power Engineering

    1995-12-01

    The connection between the expressions of optimization performances of Carnot heat engines, refrigerators and heat pumps, which operate subject to irreversible heat flow, is studied. We consider the endoreversible forward and reverse. Carnot cycles and analyse the expressions which relate efficiency, refrigeration and heating coefficients to power, refrigeration and heating rates, respectively. It is found and proved that when one of the optimal relations is derived the others are also determined, and give the unified formulation of the related optimal working temperatures of the forward and reverse Carnot cycles by isentropic temperature ratio exponent. Finally, several new optimal performance relations are derived for forward and reverse Carnot cycles under nonlinear heat transfer, and some major results in the references are easily deduced and unified in this paper. (author)

  14. Fuel utilization improvements in a once-through PWR fuel cycle. Final report on Task 6

    International Nuclear Information System (INIS)

    Dabby, D.

    1979-06-01

    In studying the position of the United States Department of Energy, Non-proliferation Alternative Systems Assessment Program, this report determines the uranium saving associated with various improvement concepts applicable to a once-through fuel cycle of a standard four-loop Westinghouse Pressurized Water Reactor. Increased discharged fuel burnup from 33,000 to 45,000 MWD/MTM could achieve a 12% U 3 O 8 saving by 1990. Improved fuel management schemes combined with coastdown to 60% power, could result in U 3 O 8 savings of 6%

  15. Improved human performance through appropriate work scheduling

    International Nuclear Information System (INIS)

    Morisseau, D.S.; Lewis, P.M.; Persensky, J.J.

    1987-01-01

    The Nuclear Regulatory Commission (NRC) has had a policy, Generic Letter 82-12, on hours of work since 1982. The policy states that licensees should establish controls to prevent situations where fatigue could reduce the ability of operating personnel to perform their duties safely (USNRC 1982). While that policy does give guidance on hours of work and overtime, it does not address periods of longer than 7 days or work schedules other than the routine 8-hour day, 40-hour week. Recognizing that NRC policy could provide broader guidance for shift schedules and hours of overtime work, the Division of Human Factors Safety conducted a project with Pacific Northwest Laboratories (PNL) to help the NRC better understand the human factors principles and issues concerning hours of work so that the NRC could consider updating their policy as necessary. The results of this project are recommendations for guidelines and limits for periods of 14 days, 28 days, and 1 year to take into account the cumulative effects of fatigue. In addition, routine 12-hour shifts are addressed. This latter type of shift schedule has been widely adopted in the petroleum and chemical industries and several utilities operating nuclear power plants have adopted it as well. Since this is the case, it is important to consider including guidelines for implementing this type of schedule. This paper discusses the bases for the PNL recommendations which are currently being studied by the NRC

  16. Baking oven improvement by performance modelling

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-01

    The first phase of the project included both the derivation of an oven model and the development of a portable, rapid-response heat-flux sensor. Heat flux (defined as the instantaneous rate of heat flow per unit at the surface of the baking biscuit and expressed in W/cm[sup 2]) has been shown to be a more useful measure of oven performance than temperature alone. Fixed-point heat-flux sensors have already been developed and marketed, but a need was expressed at the start of this project for a travelling sensor which could be used to construct a more detailed picture of heat-flux variation in an oven. The travelling monitor developed can be used to measure variations in the heat flux experienced at the surface of products being baked in a travelling oven, both when oven conditions are fixed and when they are varied. It can also be used to identify the optimum locations within an oven for fixed heat-flux probes. It has been used effectively throughout the project for both purposes. Fuel savings of 18% and 21%, respectively, were achieved with two ovens. (author)

  17. Hardfacing and packings for improved valve performance

    International Nuclear Information System (INIS)

    Aikin, J.A.; Patrick, J.N.F.; Inglis, I.

    2003-01-01

    The CANDU Owners Group (COG), Chemistry, Materials and Components (CMC) Program has supported an ongoing program on valve maintenance and performance for several years. An overview is presented of recent work on iron-based hardfacing, packing qualification, friction testing of polytetrafluoroethylene (PTFE) packings, and an investigation of re-torquing valve packing. Based on this program, two new valve-packing materials have been qualified for use in CANDU stations. By doing this, CANDU maintenance can avoid having only one packing qualified for station use, as well as assess the potential impact of the industry trend towards using lower gland loads. The results from corrosion tests by AECL and the coefficient of friction studies at Battelle' s tribology testing facilities on Delcrome 910, an iron-based hardfacing alloy, indicate it is an acceptable replacement for Stellite 6 under certain conditions. This information can be used to update in-line valve purchasing specifications. The renewed interest in friction characteristics, and environmental qualification (EQ) of packing containing PTFE has resulted in a new test program in these areas. The COG-funded valve programs have resulted in modifications to design specifications for nuclear station in-line valves and have led to better maintenance practices and valve reliability. In the end, this means lower costs and cheaper electricity. (author)

  18. Improving Vaginal Examinations Performed by Midwives

    Directory of Open Access Journals (Sweden)

    Rhoda S. Muliira

    2013-06-01

    Full Text Available A vaginal examination (VE is an essential part of midwifery care, and is routinely performed when assessing the progress of labour. As evidence shows that during labour women may find VEs unpleasant,embarrassing and sometimes painful, the aim of this article is to review literature on the use of VEs during labour and to synthesise information from the available literature on how to provide an effective VE. The studies considered were retrieved from three databases (the Cumulative Index to Nursing and Allied Health Literature [CINAHL], SCOPUS and MEDLINE using the following search terms: “VEs in labour”, “midwives and use of VEs” and “women experiences of VEs in labour”. The literature reviewed suggests that midwives are not careful about VEs. Therefore, a concerted effort is needed to pay attention to the frequency of VEs, the management ofpain and distress, information-giving and the preferences of the patient, so that the patient can feel in control during a VE.

  19. Irradiation performance of (Th,U)O2 fuel designed for advanced cycle applications

    International Nuclear Information System (INIS)

    Hastings, I.J.; Celli, A.; Onofrei, M.; Swanson, M.L.

    1982-06-01

    Our reference fabrication route for Advanced Cycle thoria-based fuel is conventional in that it produces cold-pressed and sintered pellets. However, we are also evaluating alternative fuels which offer the potential for simpler fabrication in a remote facility, and in some cases improved high burnup performance. These alternatives are impregnated, spherepac, and extruded thoria-based fuels. Spherepac fuel has been irradiated at a linear power of 50-60 kW/m to about 180 MW.h/kg H.E. There have been unexplained defects in fuel with both free-standing and collapsible cladding. Impegnated fuel has operated to 650 MW.h/kg H.E. at 50-60 kW/m. An experiment examining fuel from the sol-gel extrusion process has reached 450 Mw.h/kg H.E. at a maximum linear power of 60 kW/m. The latter two experiments have operated without defects and with fission gas release less than that for UO 2 under identical conditions. The extruded fuel has a pellet geometry similar to that for conventional fuel and is AECL's first practical demonstration of thoria-based fuel with the fissile component distributed homogeneously on an atomic scale

  20. The effects of acute creatine supplementation on multiple sprint cycling and running performance in rugby players.

    Science.gov (United States)

    Ahmun, Robert P; Tong, Richard J; Grimshaw, Paul N

    2005-02-01

    The benefits of creatine (CR) supplementation are well documented, particularly during repeated bouts of high-intensity muscular activity. Most published experiments use mass-supported (cycle ergometry) activities as a means of evaluating creatine's efficacy, therefore minimizing any possible adverse effects of increased body mass associated with CR supplementation. This study aims to use both mass-supported and mass-dependent activities to assess the effectiveness of acute CR supplementation on a group of highly trained rugby players. A randomized, double-blind, crossover research design was utilized, with subjects receiving 20 g.d(-1) x 5 d of both CR and a glucose placebo (PL). Subjects were assessed via 10 x 6-second Wingate test and a 10 x 40-m sprint test on separate days, presupplementation and postsupplementation. A 28-d washout period separated the two treatments. No significant treatment (p > 0.05) or treatment by test interaction effects (p > 0.05) were observed for peak or minimum power output (W), peak or minimum running velocity (m.s(-1)), or fatigue index (%). No significant differences (p > 0.05) were found postsupplementation for body mass and percentage body fat. Although statistical significance was not achieved for any of the measured parameters, there were small improvements in performance that may be of benefit to rugby players.

  1. Performance study of ejector cooling cycle at critical mode under superheated primary flow

    International Nuclear Information System (INIS)

    Tashtoush, Bourhan; Alshare, Aiman; Al-Rifai, Saja

    2015-01-01

    Highlights: • The ECC is modeled using EES Software and it is validated with published data. • Detailed analysis of the ECC with different refrigerants is conducted. • The constant pressure mixing is better than constant area mixing ejectors. • R134a is the selected refrigerant for the best cooling cycle performance. • The superheated primary flow at critical mode is achieved with EJ2 ejector used. - Abstract: In this work the performance of the ejector cooling cycle is investigated at critical mode, where, the effects of ejector geometry, refrigerant type, and operating condition are studied. The ejector cooling cycle is modeled with EES Software. The mass, momentum, and energy conservation principles are applied to the secondary and primary flows to investigate the performance of the ejector cooling cycle under superheated primary flow. The refrigerant R134 a is selected based on the merit of its environmental and performance characteristics. The primary working fluid in the refrigeration cycle is maintained at superheated conditions for optimal ejector performance. The solar generator temperature ranges are 80–100 °C. The operating temperature of evaporator range is 8–12 °C and the optimal condensation temperature is in the range of 28–40 °C. It is found that constant-pressure mixing ejector generates higher backpressure than constant-area mixing ejector for the same entrainment ratio and COP. The type of ejector is selected based on the performance criteria of the critical backpressure and choking condition of the primary flow, the so called EJ2 type ejector meets the criteria. The COP is found to be in the range of 0.59–0.67 at condenser backpressure of 24 bar due to higher critical condenser pressure and higher generator temperature

  2. Improved thermal cycling durability and PCR compatibility of polymer coated quantum dot

    International Nuclear Information System (INIS)

    Xun Zhe; Guan Yifu; Zhao Xiaoyun

    2013-01-01

    Quantum dots have experienced rapid development in imaging, labeling and sensing in medicine and life science. To be suitable for polymerase chain reaction (PCR) assay, we have tested QD thermal cycling durability and compatibility, which have not been addressed in previous reports. In this study, we synthesized CdSe/ZnS QDs with a surface modification with high-MW amphiphilic copolymers and observed that Mg 2+ ions in the PCR reaction could induce the QDs to precipitate and reduce their fluorescence signal significantly after thermal cycling. To overcome this problem, we used mPEG2000 to conjugate the QD surface for further protection, and found that this modification enables QDs to endure 40 thermal cycles in the presence of other components essential for PCR reactions. We have also identified that QDs have different effects on rTaq and Ex Taq polymerization systems. A high QD concentration could apparently reduce the PCR efficiency, but this inhibition was relieved significantly in the Ex PCR system as the concentration of Ex Taq polymerase was increased. Real-time PCR amplification results showed that QDs could provide a sufficiently measurable fluorescence signal without excessively inhibiting the DNA amplification. Based on this improved thermal cycling durability and compatibility with the PCR system, QDs have the potential to be developed as stable fluorescent sensors in PCR and real-time PCR amplification. (paper)

  3. Squat Jump Performance during Growth in Both Sexes: Comparison with Cycling Power

    Science.gov (United States)

    Dore, Eric; Bedu, Mario; Van Praagh, Emmanuel

    2008-01-01

    The purpose of this cross-sectional study was to investigate leg muscle power and compare two activities (jumping and cycling) in 383 girls and 407 boys ages 9-19 years. Results in anthropometric characteristics and jumping performance were comparable until midadolescence, and sex differences were observed. Lean leg volume (LLV) was the reason for…

  4. Towards cycle-accurate performance predictions for real-time embedded systems

    NARCIS (Netherlands)

    Triantafyllidis, K.; Bondarev, E.; With, de P.H.N.; Arabnia, H.R.; Deligiannidis, L.; Jandieri, G.

    2013-01-01

    In this paper we present a model-based performance analysis method for component-based real-time systems, featuring cycle-accurate predictions of latencies and enhanced system robustness. The method incorporates the following phases: (a) instruction-level profiling of SW components, (b) modeling the

  5. Life cycle environmental performance of miscanthus gasification versus other technologies for electricity production

    DEFF Research Database (Denmark)

    Nguyen, T Lan T; Hermansen, John Erik

    2015-01-01

    In this paper, the life cycle environmental performance of miscanthus gasification for electricity production in Denmark is evaluated and compared with that of direct combustion and anaerobic digestion. Furthermore, the results obtained are compared to those of natural gas to assess the potential...

  6. Life cycle assessment of sisal fibre – Exploring how local practices can influence environmental performance

    NARCIS (Netherlands)

    Broeren, M.L.M.; Dellaert, S.N.C.; Cok, B.; Patel, M.K.; Worrell, E.; Shen, L.

    2017-01-01

    Sisal fibre can potentially replace glass fibre in natural fibre composites. This study focuses on the environmental performance of sisal fibre production by quantifying the greenhouse gas (GHG) emissions and energy use of producing sisal fibre in Tanzania and Brazil using life cycle assessment

  7. Performance of a Throttle Cycle Refrigerator with Nitrogen-Hydrocarbon and Argon-Hydrocarbon Mixtures

    Science.gov (United States)

    Venkatarathnam, G.; Senthil Kumar, P.; Srinivasa Murthy, S.

    2004-06-01

    Throttle cycle refrigerators are a class of vapor compression refrigerators that can provide refrigeration at cryogenic temperatures and operate with refrigerant mixtures. The performance of our prototype refrigerators with nitrogen-hydrocarbon, nitrogen-hydrocarbon-helium and argon-hydrocarbon refrigerant mixtures is presented in this paper.

  8. Monitoring Perceived Stress and Recovery in Relation to Cycling Performance in Female Athletes

    NARCIS (Netherlands)

    Otter, R. T. A.; Brink, M. S.; van der Does, H. T. D.; Lemmink, K. A. P. M.

    The purpose was to investigate perceived stress and recovery related to cycling performance of female athletes over one full year. 20 female athletes ( age, 27 +/- 8 years; VO2max, 50.3 +/- 4.6 mL center dot kg(-1) center dot min(-1)) were measured 8 times in one year to determine perceived stress

  9. Performance analysis of double organic Rankine cycle for discontinuous low temperature waste heat recovery

    International Nuclear Information System (INIS)

    Wang Dongxiang; Ling Xiang; Peng Hao

    2012-01-01

    This research proposes a double organic Rankine cycle for discontinuous waste heat recovery. The optimal operation conditions of several working fluids have been calculated by a procedure employing MATLAB and REFPROP. The influence of outlet temperature of heat source on the net power output, thermal efficiency, power consumption, mass flow rate, expander outlet temperature, cycle irreversibility and exergy efficiency at a given pinch point temperature difference (PPTD) has been analyzed. Pinch point analysis has also been employed to obtain a thermodynamic understanding of the ORC performance. Of all the working fluids investigated, some performances between each working fluid are rather similar. For a fixed low temperature heat source, the optimal operation condition should be mainly determined by the heat carrier of the heat source, and working fluids have limited influence. Lower outlet temperature of heat source does not always mean more efficient energy use. Acetone exhibits the least exergy destruction, while R245fa possesses the maximal exergy efficiency at a fixed PPTD. Wet fluids exhibit lower thermal efficiency than the others with the increasing of PPTD at a fixed outlet temperature of heat source. Dry and isentropic fluids offer attractive performance. - Highlights: ► We propose a double organic Rankine cycle for discontinuous waste heat recovery. ► Performance of organic Rankine cycle (ORC) is analyzed by pinch point analysis. ► The heat carrier of the heat source determines ORC optimal operation condition. ► Design of ORC heat exchangers prefers lower pinch point temperature difference.

  10. Ad-libitum drinking and performance during a 40-km cycling time trial in the heat

    NARCIS (Netherlands)

    Berkulo, M.A.R.; Bol, S.; Levels, K.; Lamberts, R.P.; Daanen, H.A.M.; Noakes, T.D.

    2015-01-01

    The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and

  11. Ad-libitum drinking and performance during a 40-km cycling time trial in the heat

    NARCIS (Netherlands)

    Berkulo, M.A.R.; Bol, S.; Levels, K.; Lamberts, R.P.; Daanen, H.A.M.; Noakes, T.D.

    2016-01-01

    The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and

  12. Design of organic Rankine cycle power systems accounting for expander performance

    DEFF Research Database (Denmark)

    La Seta, Angelo; Andreasen, Jesper Graa; Pierobon, Leonardo

    2015-01-01

    Organic Rankine cycle power systems have recently emerged as promising solutions for waste heat recovery in low- and medium-size power plants. Their performance and economic feasibility strongly depend on the expander. Its design process and efficiency estimation are particularly challenging due...

  13. The effect of skin temperature on performance during a 7.5-km cycling time trial

    NARCIS (Netherlands)

    Levels, K.; de Koning, J.J.; Foster Jr., C.C.; Daanen, H.A.M.

    2012-01-01

    Aerobic exercise performance is seriously compromised in the heat. Possibly, a high skin temperature causes a rating of perceived exertion (RPE)-mediated decrease in exercise intensity. The purpose of this study was to determine the effect of skin temperature on power output during a 7.5-km cycling

  14. Human Performance: Women in Nontraditional Occupations and the Influence of the Menstrual Cycle (A Selected Bibliography)

    Science.gov (United States)

    1980-05-01

    82171. Women in the Labor Force. 3. Work Patterns of Women. 10. Unemployed Women. 15. Women as Family Heads. 21. Working Wives. 32. Employment by...reaction time in the menstrual cycle.] Sportarzt u Sportsmedizin, 1968, 19, 73. - 19. Hildebrandt, G., & Witzenrath, A. [ Psychic performance and

  15. Optimal thermoeconomic performance of an irreversible regenerative ferromagnetic Ericsson refrigeration cycle

    International Nuclear Information System (INIS)

    Xu, Zhichao; Guo, Juncheng; Lin, Guoxing; Chen, Jincan

    2016-01-01

    On the basis of the Langevin theory of classical statistical mechanics, the magnetization, entropy, and iso-field heat capacity of ferromagnetic materials are analyzed and their mathematical expressions are derived. An irreversible regenerative Ericsson refrigeration cycle by using a ferromagnetic material as the working substance is established, in which finite heat capacity rates of low and high temperature reservoirs, non-perfect regenerative heat of the refrigeration cycle, additional regenerative heat loss, etc. are taken into account. Based on the regenerative refrigeration cycle model, a thermoeconomic function is introduced as one objective function and optimized with respect to the temperatures of the working substance in the two iso-thermal processes. By means of numerical calculation, the effects of the effective factor of the heat exchangers in high/low temperature reservoir sides, efficiency of the regenerator, heat capacity rate of the low temperature reservoir, and applied magnetic field on the optimal thermoeconomic function as well as the corresponding cooling rate and coefficient of performance are revealed. The results obtained in this paper can provide some theoretical guidance for the optimal design of actual regenerative magnetic refrigerator cycle. - Highlights: • Thermodynamic performance of ferromagnetic material is analyzed. • An irreversible regenerative ferromagnetic Ericsson refrigeration cycle is set up. • The thermoeconomic objective function is introduced and optimized. • Impacts of the thermoeconomic and other parameters are discussed.

  16. Experimental Investigation of the Performance of a Hermetic Screw-Expander Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Sung-Wei Hsu

    2014-09-01

    Full Text Available In this study, the authors experimentally investigate the performance of the organic Rankine cycle (ORC and screw expander under the influence of supply pressure and pressure ratio over the expander. Three tests were performed with expander pressure ratios of 2.4–3.5, 3.0–4.6, and 3.3–6.1, which cover the over-expansion and under-expansion operating modes. The test results show a maximum expander isentropic efficiency of 72.4% and a relative cycle efficiency of 10.5% at an evaporation temperature of 101 °C and condensation temperature of 45 °C. At a given pressure ratio over the expander, a higher supply pressure to the expander causes a higher expander isentropic efficiency and higher cycle efficiency in the over-expansion mode. However, in the under-expansion mode, the higher supply pressure results in a lower expander isentropic efficiency and adversely affects the cycle efficiency. The results also show that under the condition of operation at a given pressure ratio, a higher supply pressure yields a larger power output owing to the increased mass flow rate at the higher supply pressure. The study results demonstrate that a screw-expander ORC can be operated with a wide range of heat sources and heat sinks with satisfactory cycle efficiency.

  17. The neutronic and fuel cycle performance of interchangeable 3500 MWth metal and oxide fueled LMRs

    International Nuclear Information System (INIS)

    Fujita, E.K.; Wade, D.C.

    1990-01-01

    This study summarizes the neutronic and fuel cycle analysis performed at Argonne National Laboratory for an oxide and a metal fueled 3500 MWth LMR. These reactor designs formed the basis for a joint US/European study of LMR ATWS events. The oxide and metal core designs were developed to meet reactor performance specifications that are constrained by requirements for core loading interchangeability and for a small burnup reactivity swing. Differences in the computed performance parameters of the oxide and metal cores, arising from basic differences in their neutronic characteristics, are identified and discussed. It is shown that metal and oxide cores designed to the same ground rules exhibit many similar performance characteristics; however, they differ substantially in reactivity coefficients, control strategies, and fuel cycle options. 12 refs., 2 figs., 12 tabs

  18. Thermal performance analysis of Brayton cycle with waste heat recovery boiler for diesel engines of offshore oil production facilities

    International Nuclear Information System (INIS)

    Liu, Xianglong; Gong, Guangcai; Wu, Yi; Li, Hangxin

    2016-01-01

    Highlights: • Comparison of Brayton cycle with WHRB adopted in diesel engines with and without fans by thermal performance. • Waste heat recovery technology for FPSO. • The thermoeconomic analysis for the heat recovery for FPSO. - Abstract: This paper presents the theoretical analysis and on-site testing on the thermal performance of the waste heat recovery system for offshore oil production facilities, including the components of diesel engines, thermal boilers and waste heat boilers. We use the ideal air standard Brayton cycle to analyse the thermal performance. In comparison with the traditional design, the fans at the engine outlet of the waste heat recovery boiler is removed due to the limited space of the offshore platform. The cases with fan and without fan are compared in terms of thermal dynamics performance, energy efficiency and thermo-economic index of the system. The results show that the application of the WHRB increases the energy efficiency of the whole system, but increases the flow resistance in the duct. It is proved that as the waste heat recovery boiler takes the place of the thermal boiler, the energy efficiency of whole system without fan is slightly reduced but heat recovery efficiency is improved. This research provides an important guidance to improve the waste heat recovery for offshore oil production facilities.

  19. Performance Changes of Elite Paralympic Judo Athletes During a Paralympic Games Cycle: A Case Study with the Brazilian National Team.

    Science.gov (United States)

    Loturco, Irineu; Pereira, Lucas A; Winckler, Ciro; Bragança, Jaime R; da Fonseca, Roger A; Kobal, Ronaldo; Cal Abad, Cesar C; Kitamura, Katia; Nakamura, Fabio Y; Franchini, Emerson

    2017-12-01

    The aim of this study was to describe the variations in power performance of elite Paralympic judo athletes across three consecutive training cycles of preparation for the ParaPan American Games, the World Championship and the Paralympic Games. Eleven Paralympic judokas from the Brazilian National team participated in this study. They were repeatedly assessed using squat and countermovement jumps, mean propulsive power (MPP) in the jump-squat (JS), the bench press and prone bench pull at several moments of the preparation. Training supervision based on the optimum power zone (range of loads where power production is maximized) was provided in the final cycle, prior to the Paralympic Games. Magnitude-based inference was used to compare the repeated measurements of power performance. Lower and upper limb muscle power gradually increased throughout the cycles; however, the best results in all exercises were observed prior to the Paralympic Games, during which the team won four silver medals. As an illustration, prior to participation in the Paralympic Games the MPP in the JS was likely to very likely higher than prior to the World Championship (effect size [ES] = 0.77) and ParaPan American Games (ES = 0.53), and in January and March 2016 (ES = 0.98 and 0.92, respectively; months preceding the Paralympic Games). Power performance assessments can provide information about the evolution of Paralympic judokas, and training at the optimum power zone seems to constitute an effective method to improve lower and upper limb power in these athletes.

  20. Blastocyst transfer does not improve cycle outcome as compared to D3 transfer in antagonist cycles with an elevated progesterone level on the day of hCG.

    Science.gov (United States)

    Demirel, Cem; Aydoğdu, Serkan; Özdemir, Arzu İlknur; Keskin, Gülşah; Baştu, Ercan; Buyru, Faruk

    2017-09-01

    To evaluate the association between progesterone elevation on the day of human chorionic gonadotropin (hCG) administration and clinical pregnancy rates of gonadotropin-releasing hormone (GnRH) antagonist in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles with the transfer of embryos at different developmental stages (day-3 versus day-5 ETs). This is a retrospective analysis of fresh IVF/ICSI; 194 cycles out of 2676 conducted in a single center. A total of 2676 cycles were analyzed, of which 386 had no progesterone measurements available. Two hundred eighteen cycles had progesterone elevation (p>1.5 ng/mL) giving an overall incidence of 9.5%. Twenty-four cycles were excluded from further analysis. Of the remaining 194 cycles, 151 had day-3 transfers and 43 had blastocyst transfers. There was no statistically significant difference in pregnancy and clinical pregnancy rates per transfer between the D3-ET and D5-ET groups (46% vs. 49%, and 39% vs. 35%, respectively). The results of this study suggest that blastocyst transfer does not improve cycle outcomes compared with D3 transfer in GnRH antagonist cycles with an elevated progesterone level on the day of hCG.

  1. Assisted Hatching and Intracytoplasmic Sperm Injection are not Associated with Improved Outcomes in ART Cycles for Diminished Ovarian Reserve: An Analysis of US Cycles from 2004–2011

    Science.gov (United States)

    Butts, Samantha F.; Owen, Carter; Mainigi, Monica; Senapati, Suneeta; Seifer, David B.; Dokras, Anuja

    2014-01-01

    Objective To investigate the impact of intracytoplasmic sperm injection (ICSI) and assisted hatching (AH) on ART outcomes in cycles with diminished ovarian reserve (DOR) as the primary diagnosis. Design Retrospective cohort study of cycles from the SART-CORS database. Setting NA. Patient(s) A total of 422,949 fresh, non-donor, initial ART cycles of which 8,597 were diagnosed with only elevated FSH and 38,926 were diagnosed with only DOR according to the SART DOR categorization. Intervention(s) None. Main Outcome Measure(s) Live birth and clinical pregnancy rates. Result(s) ICSI and AH were associated with diminished odds of live birth in SART DOR only cycles (AOR, 95% CI 0.88, 0.81–0.96 for ICSI; AOR, 95% CI 0.77 0.71–0.84 for AH). No association between either ICSI or AH in Elevated FSH only cycles was observed. The combination of ICSI and AH resulted in significantly lower odds of live birth in SART DOR only cycles but not in Elevated FSH only cycles. Conclusion(s) In initial ART cycles for which the only indication relates to a diagnosis of diminished ovarian reserve, assisted hatching and ICSI are not associated with improved live birth rates. PMID:25086790

  2. Hypersonic ramjet experiment project. Phase 1: Computer program description, ramjet and scramjet cycle performance

    Science.gov (United States)

    Jackson, R. J.; Wang, T. T.

    1974-01-01

    A computer program was developed to describe the performance of ramjet and scramjet cycles. The program performs one dimensional calculations of the equilibrium, real-gas internal flow properties of the engine. The program can be used for the following: (1) preliminary design calculation and (2) design analysis of internal flow properties corresponding to stipulated flow areas. Only the combustion of hydrogen in air is considered in this case.

  3. Complex Heat Exchangers for Improved Performance

    Science.gov (United States)

    Bran, Gabriela Alejandra

    propagates along the channel. However, the sinusoidal behavior on one of the fluids does not fully translate to the other gets damped by the wall and the heat transfer coefficients that can be barely seen on the other flow. A scaling analysis and a parametric study were performed to determine the influence the different parameters on the system have on the time a heat exchanger takes to reach steady state. The results show the dependency of tst* (time a system takes to reach steady state) on the dimensionless parameters M, C, NTUh, NTUc, and Cw. t st* depends linearly on C and Cw, and it is a power function of M. It was also shown that tst* has a logarithmic dependency on NTUh and NTUc. A correlation was generated to approximate the time a system takes to reach steady state for systems where C w heat exchanger with the specific application of solar energy storage was also investigated. This application involves a counter-flow heat exchanger with a reacting flow in one of the channels, and it includes varying properties, heat generation, varying heat transfer coefficient, and axial conduction. The application for this reactor heat exchanger is on solar energy storage, and the goals is to heat up steam to 650 °C by using the ammonia synthesis heat of reaction. One of the concerns for this system is the start-up time and also how disturbances in reacting flow can affect the steam outlet temperature. The transient behavior during the system start-up was presented. In order to achieve the desired outlet steam temperature at a reasonable time, the system must operate at high gas mass flow rates. If the inlet temperature of the gas suffers a step change, it affects the reaction rate as well as the outlet steam temperature. A small perturbation on the gas mass flow rate has an effect on the profile shape. However, the maximum temperature reached by the gas due to reaction is not affected, and consequently, it has little effect on the steam temperature. Axial conduction in the

  4. Performance Improvement Quarterly. Volume 15, Number 1, 2002

    National Research Council Canada - National Science Library

    2002-01-01

    Performance Improvement Quarterly (PIQ) is a peer-reviewed journal whose goal is to stimulate professional discussion in the field and to advance the discipline of performance technology through the publication of scholarly works...

  5. The effects of menstrual cycle phase on physical performance in female soccer players

    Science.gov (United States)

    Julian, Ross; Hecksteden, Anne; Fullagar, Hugh H. K.; Meyer, Tim

    2017-01-01

    Background Female soccer has grown extensively in recent years, however differences in gender-specific physiology have rarely been considered. The female reproductive hormones which rise and fall throughout the menstrual cycle, are known to affect numerous cardiovascular, respiratory, thermoregulatory and metabolic parameters, which in turn, may have implications on exercise physiology and soccer performance. Therefore, the main aim of the present study was to investigate potential effects of menstrual cycle phase on performance in soccer specific tests. Methods Nine sub elite female soccer players, all of whom have menstrual cycles of physiological length; performed a series of physical performance tests (Yo-Yo Intermittent endurance test (Yo-Yo IET), counter movement jump (CMJ) and 3x30 m sprints). These were conducted at distinct time points during two main phases of the menstrual cycle (early follicular phase (FP) and mid luteal phase (LP)) where hormones contrasted at their greatest magnitude. Results Yo-Yo IET performance was considerably lower during the mid LP (2833±896 m) as compared to the early FP (3288±800 m). A trend towards significance was observed (p = 0.07) and the magnitude based inferences suggested probabilities of 0/61/39 for superiority/equality/inferiority of performance during the mid LP, leading to the inference of a possibly harmful effect. For CMJ (early FP, 20.0±3.9 cm; mid LP 29.6±3.0 cm, p = 0.33) and sprint (early FP, 4.7±0.1 s; mid LP, 4.7±0.1 s, p = 0.96) performances the results were unclear (8/24/68, 48/0/52, respectively). Conclusion The results of this study are in support of a reduction in maximal endurance performance during the mid LP of the menstrual cycle. However, the same effect was not observed for jumping and sprint performance. Therefore, consideration of cycle phase when monitoring a player’s endurance capacity may be worthwhile. PMID:28288203

  6. Influence of precooling cooling air on the performance of a gas turbine combined cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Ik Hwan; Kang, Do Won; Kang, Soo Young; Kim, Tong Seop [Inha Univ., Incheon (Korea, Republic of)

    2012-02-15

    Cooling of hot sections, especially the turbine nozzle and rotor blades, has a significant impact on gas turbine performance. In this study, the influence of precooling of the cooling air on the performance of gas turbines and their combined cycle plants was investigated. A state of the art F class gas turbine was selected, and its design performance was deliberately simulated using detailed component models including turbine blade cooling. Off design analysis was used to simulate changes in the operating conditions and performance of the gas turbines due to precooling of the cooling air. Thermodynamic and aerodynamic models were used to simulate the performance of the cooled nozzle and rotor blade. In the combined cycle plant, the heat rejected from the cooling air was recovered at the bottoming steam cycle to optimize the overall plant performance. With a 200K decrease of all cooling air stream, an almost 1.78% power upgrade due to increase in main gas flow and a 0.70 percent point efficiency decrease due to the fuel flow increase to maintain design turbine inlet temperature were predicted.

  7. Analyze and Improve Lifetime in 3L-NPC Inverter from Power Cycle and Thermal Balance

    DEFF Research Database (Denmark)

    Chen, Quan; Chen, Zhe; Wang, Qunjing

    2014-01-01

    Three-level Neutral-point-clamped (3L-NPC) topology is becoming a realistic alternative to the conventional one in high-voltage and high-power application. Studies show that the power cycling mean time to failure (MTTF) of the semiconductor bond wire in 3L-NPC inverter system may be very short...... under some common conditions. Firstly, this paper shows the impact of some key parameters on power electronic system lifetime according the analysis of semiconductor failure mechanism. Secondly, a switching frequency reduction method based on the position relationship between the flowing current...... and load voltage is applied to reduce power cycle and switching losses. And then, three-level active neutral point-clamped topology is taken into account to wake the most thermo stressed device. In order to validate the improve lifetime method in this paper, a 2MW 3L-NPC converter used in wind energy has...

  8. An implementation of 7E Learning Cycle Model to Improve Student Self-esteem

    Science.gov (United States)

    Firdaus, F.; Priatna, N.; Suhendra, S.

    2017-09-01

    One of the affective factors that affect student learning outcomes is student self-esteem in mathematics, learning achievement and self-esteem influence each other. The purpose of this research is to know whether self-esteem students who get 7E learning cycle model is better than students who get conventional learning. This research method is a non-control group design. Based on the results obtained that the normal and homogeneous data so that the t test and from the test results showed there are significant differences in self-esteem students learning with 7E learning cycle model compared with students who get conventional learning. The implications of the results of this study are that students should be required to conduct many discussions, presentations and evaluations on classroom activities as these learning stages can improve students’ self-esteem especially pride in the results achieved.

  9. Teori Adult Learning, Ekspriental Learning Cycle Dan Perubahan Performance Individu Dalam Pendidikan Dan Pelatihan

    Directory of Open Access Journals (Sweden)

    Moh. Dannur

    2017-07-01

    Full Text Available Teori belajar merupakan hal yang sangat penting dalam Manajmen Pendidikan dan Pelatihan apabila ingin meraih hasil yang maksimal dalam proses transformasi pengetahuan. Adult Learning dan Ekspriental Learning Cycle salah satu teori yang paling masyhur di dalamnya. Dalam upaya meraih hasil yang maksimal juga perlu adanya pengetahuan tentang motivasi dan faktor-faktor dalam pengembangan individu, perubahan performanya, serta dinamika individu kelompok. Sehingga dengan pengetahuan yang dimilikiakan dengan mudah merealisasikan yang diinginkan. Kata kunci: Adult learning, expriental learning cycle, performance.  Learning theory is very important in Management of Education and Training if you want to achieve the maximum results in the transformation process of knowledge. Adult Learning and Expriental Learning Cycle are the most famous theories within it. In the effort to achieve the maximum results also needs the knowledge about motivation, the factors in the development of individuals, the changes of performance, and the dynamics of individual groups. So with this knowledge you will easily realize the thing you desired. Keywords: Adult learning, expriental learning cycle, performance.

  10. Single and combined effects of beetroot juice and caffeine supplementation on cycling time trial performance.

    Science.gov (United States)

    Lane, Stephen C; Hawley, John A; Desbrow, Ben; Jones, Andrew M; Blackwell, James R; Ross, Megan L; Zemski, Adam J; Burke, Louise M

    2014-09-01

    Both caffeine and beetroot juice have ergogenic effects on endurance cycling performance. We investigated whether there is an additive effect of these supplements on the performance of a cycling time trial (TT) simulating the 2012 London Olympic Games course. Twelve male and 12 female competitive cyclists each completed 4 experimental trials in a double-blind Latin square design. Trials were undertaken with a caffeinated gum (CAFF) (3 mg·kg(-1) body mass (BM), 40 min prior to the TT), concentrated beetroot juice supplementation (BJ) (8.4 mmol of nitrate (NO3(-)), 2 h prior to the TT), caffeine plus beetroot juice (CAFF+BJ), or a control (CONT). Subjects completed the TT (females: 29.35 km; males: 43.83 km) on a laboratory cycle ergometer under conditions of best practice nutrition: following a carbohydrate-rich pre-event meal, with the ingestion of a carbohydrate-electrolyte drink and regular oral carbohydrate contact during the TT. Compared with CONT, power output was significantly enhanced after CAFF+BJ and CAFF (3.0% and 3.9%, respectively, p caffeine (-0.9%, p = 0.4 compared with CAFF). We conclude that caffeine (3 mg·kg(-1) BM) administered in the form of a caffeinated gum increased cycling TT performance lasting ∼50-60 min by ∼3%-4% in both males and females. Beetroot juice supplementation was not ergogenic under the conditions of this study.

  11. Improving visit cycle time using patient flow analysis in a high-volume inner-city hospital-based ambulatory clinic serving minority New Yorkers.

    Science.gov (United States)

    Dhar, Sanjay; Michel, Raquel; Kanna, Balavenkatesh

    2011-01-01

    Patient waiting time and waiting room congestion are quality indicators that are related to efficiency of ambulatory care systems and patient satisfaction. Our main purpose was to test a program to decrease patient visit cycle time, while maintaining high-quality healthcare in a high-volume inner-city hospital-based clinic in New York City. Use of patient flow analysis and the creation of patient care teams proved useful in identifying areas for improvement, target, and measure effectiveness of interventions. The end result is reduced visit cycle time, improved provider team performance, and sustained patient care outcomes. © 2010 National Association for Healthcare Quality.

  12. The Impact of a Participant-Based Accounting Cycle Course on Student Performance in Intermediate Financial Accounting I

    Science.gov (United States)

    Siagian, Ferdinand T.; Khan, Mohammad

    2016-01-01

    The authors investigated whether students in an Intermediate Financial Accounting I course who took a 1-credit, participant-based accounting cycle course performed better than students who did not take the accounting cycle course. Results indicate a higher likelihood of earning a better grade for students who took the accounting cycle course even…

  13. Performance Analysis of Permanent Magnet Motors for Electric Vehicles (EV Traction Considering Driving Cycles

    Directory of Open Access Journals (Sweden)

    Thanh Anh Huynh

    2018-05-01

    Full Text Available This paper evaluates the electromagnetic and thermal performance of several traction motors for electric vehicles (EVs. Two different driving cycles are employed for the evaluation of the motors, one for urban and the other for highway driving. The electromagnetic performance to be assessed includes maximum motor torque output for vehicle acceleration and the flux weakening capability for wide operating range under current and voltage limits. Thermal analysis is performed to evaluate the health status of the magnets and windings for the prescribed driving cycles. Two types of traction motors are investigated: two interior permanent magnet motors and one permanent magnet-assisted synchronous reluctance motor. The analysis results demonstrate the benefits and disadvantages of these motors for EV traction and provide suggestions for traction motor design. Finally, experiments are conducted to validate the analysis.

  14. Top Management Team Diversity and Company Performance: The moderating effect of Organization Life Cycle

    Directory of Open Access Journals (Sweden)

    Emil Velinov

    2016-12-01

    Full Text Available The research paper examines the moderating impact of Organizational Life Cycle on the relationship between Top Management Team Diversity and Company Performance. The study first elaborates and establishes the theoretical link between organization lifecycle and composition of management elites. Second, a quantitative empirical study is conducted to test the OLC stages moderating impact on the upper echelons diversity and firm performance of the top companies in the Czech Republic. A detailed procedure is developed to accurately classify organizations at different lifecycle stages, drawing extensively on existing literature and scales. Paper findings state that more mature the company becomes, more diversified the senior management is regardless the firm performance. Also, the industry dynamism impact has its own role in the relationship between the organization life cycle and senior management diversity which is expressed by the paper findings as well.

  15. Metrics Feedback Cycle: measuring and improving user engagement in gamified eLearning systems

    Directory of Open Access Journals (Sweden)

    Adam Atkins

    2017-12-01

    Full Text Available This paper presents the identification, design and implementation of a set of metrics of user engagement in a gamified eLearning application. The 'Metrics Feedback Cycle' (MFC is introduced as a formal process prescribing the iterative evaluation and improvement of application-wide engagement, using data collected from metrics as input to improve related engagement features. This framework was showcased using a gamified eLearning application as a case study. In this paper, we designed a prototype and tested it with thirty-six (N=36 students to validate the effectiveness of the MFC. The analysis and interpretation of metrics data shows that the gamification features had a positive effect on user engagement, and helped identify areas in which this could be improved. We conclude that the MFC has applications in gamified systems that seek to maximise engagement by iteratively evaluating implemented features against a set of evolving metrics.

  16. Improving evaluation of climate change impacts on the water cycle by remote sensing ET-retrieval

    Directory of Open Access Journals (Sweden)

    S. G. García Galiano

    2015-05-01

    Full Text Available Population growth and intense consumptive water uses are generating pressures on water resources in the southeast of Spain. Improving the knowledge of the climate change impacts on water cycle processes at the basin scale is a step to building adaptive capacity. In this work, regional climate model (RCM ensembles are considered as an input to the hydrological model, for improving the reliability of hydroclimatic projections. To build the RCMs ensembles, the work focuses on probability density function (PDF-based evaluation of the ability of RCMs to simulate of rainfall and temperature at the basin scale. To improve the spatial calibration of the continuous hydrological model used, an algorithm for remote sensing actual evapotranspiration (AET retrieval was applied. From the results, a clear decrease in runoff is expected for 2050 in the headwater basin studied. The plausible future scenario of water shortage will produce negative impacts on the regional economy, where the main activity is irrigated agriculture.

  17. Thermodynamic performance comparison between ORC and Kalina cycles for multi-stream waste heat recovery

    International Nuclear Information System (INIS)

    Wang, Yufei; Tang, Qikui; Wang, Mengying; Feng, Xiao

    2017-01-01

    Highlights: • Comparison between ORC and Kalina cycles (KC) for multi-stream waste heat recovery. • Divide waste heat into straight, convex and concave based on its composite curve. • Use heat ratio and temperature of the most point to show the feature of waste heat. • KC is suitable for straight and most concave heat, while ORC for convex one. - Abstract: Organic Rankine cycle (ORC) and Kalina cycle are the main technologies to recover waste heat for power generation. Up to now, many works dealing with the thermodynamic performance comparison between ORC and Kalina cycles are available, but these studies considered for heat recovery from a single heat source or stream. In the process industry, there are multiple waste heat streams, forming a complex heat source profile. In this paper, based on the simulation model developed in the Aspen Hysys software, the two cycles are calculated and compared. According to the waste heat composite curve, the multi-stream waste heat is divided into three kinds, straight, convex, and concave waste heat. Two parameters, the ratio of the heat above and below the most salient/concave point (R) and the temperature of the most point, are used to roughly express the feature of waste heat. With the efficiency from waste heat (exergy) to power as energy performance indicator, the calculation results for waste heat with maximum supply temperature 180 °C show that for straight and concave waste heat with R not less than 0.2, Kalina cycle is better than ORC, while for convex waste heat, ORC is preferable. The work can provide a reference to choose a suitable technology to recover low temperature waste heat for power generation in the process industry.

  18. Improving Manufacturing Performance in South Africa : Report of the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    1995-01-01

    Improving Manufacturing Performance in South Africa : Report of the Industrial Strategy Project. Couverture du livre Improving Manufacturing Performance in South Africa. Author(s):. Avril Joffe, David Kaplan, Raphael Kaplinsky et David Lewis. Publisher(s):. UCT Press, CRDI. January 1, 1995. ISBN: Épuisé. 264 pages.

  19. Glucocorticoids improve high-intensity exercise performance in humans

    DEFF Research Database (Denmark)

    Casuso, Rafael A; Melskens, Lars; Bruhn, Thomas

    2014-01-01

    It was investigated whether oral dexamethasone (DEX) administration improves exercise performance by reducing the initial rate of muscle fatigue development during dynamic exercise.......It was investigated whether oral dexamethasone (DEX) administration improves exercise performance by reducing the initial rate of muscle fatigue development during dynamic exercise....

  20. Effect of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in the heat.

    Science.gov (United States)

    Beaumont, Ross E; James, Lewis J

    2017-11-01

    This study investigated the influence of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in high ambient temperature. Double-blind cross-over study. Eight healthy, recreationally active males (mean±SD; age: 22±1 years; body mass: 71.1±8.5kg; VO 2peak : 55.9±5.8mLkg -1 min -1 ; W max : 318±37W) completed one VO 2peak test, one familiarisation trial and two experimental trials. After an overnight fast, participants ingested a placebo or a 6mgkg -1 caffeine dose 60min before exercise. The exercise protocol consisted of 60min of cycle exercise at 55% W max , followed by a 30min performance task (total kJ produced) in 30°C and 50% RH. Performance was enhanced (Cohen's d effect size=0.22) in the caffeine trial (363.8±47.6kJ) compared with placebo (353.0±49.0kJ; p=0.004). Caffeine did not influence core (p=0.188) or skin temperature (p=0.577) during exercise. Circulating prolactin (p=0.572), cortisol (p=0.842) and the estimated rates of fat (p=0.722) and carbohydrate oxidation (p=0.454) were also similar between trial conditions. Caffeine attenuated perceived exertion during the initial 60min of exercise (p=0.033), with no difference in thermal stress across trials (p=0.911). Supplementation with 6mgkg -1 caffeine improved endurance cycle performance in a warm environment, without differentially influencing thermoregulation during prolonged exercise at a fixed work-rate versus placebo. Therefore, moderate caffeine doses which typically enhance performance in temperate environmental conditions also appear to benefit endurance performance in the heat. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Improvement of Wind Farm Performance by Means of Spinner Anemometry

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels; Demurtas, Giorgio; Gottschall, Julia

    This report is a project report on the EUDP research project SpinnerFarm. The objectives of the project were to improve software and hardware on the spinner anemometer concept and to demonstrate improvement of wind farm performance by opitmized yaw control. The hardware was improved by a more...

  2. Experience of safety and performance improvement for fuel handling equipment

    International Nuclear Information System (INIS)

    Gyoon Chang, Sang; Hee Lee, Dae

    2014-01-01

    The purpose of this study is to provide experience of safety and performance improvement of fuel handling equipment for nuclear power plants in Korea. The fuel handling equipment, which is used as an important part of critical processes during the refueling outage, has been improved to enhance safety and to optimize fuel handling procedures. Results of data measured during the fuel reloading are incorporated into design changes. The safety and performance improvement for fuel handling equipment could be achieved by simply modifying the components and improving the interlock system. The experience provided in this study can be useful lessons for further improvement of the fuel handling equipment. (authors)

  3. Improve strategic supplier performance using DMAIC to develop a Quality Improvement Plan

    Science.gov (United States)

    Jardim, Kevin P.

    Supplier performance that meets the requirements of the customer has long plagued quality professionals. Despite the vast efforts by organizations to improve supplier performance, little has been done to standardize the plan to improve performance. This project presents a guideline and problem-solving strategy using a Define, Measure, Analyze, Improve, and Control (DMAIC) structured tool that will assist in the management and improvement of supplier performance. An analysis of benchmarked Quality Improvement Plans indicated that this topic needs more focus on how to accomplish improved supplier performance. This project is part of a growing body of supplier continuous improvement efforts. With the input of Zodiac Aerospace quality professionals this project's results provide a solution to Quality Improvement Plans and show objective evidence of its benefits. This project contributes to the future research on similar topics.

  4. Learning by doing – creating competences in engineering students on how and when to perform and use life cycle assessments

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky

    2003-01-01

    The course Life cycle assessment of products and systems has been given for eight consecutive years at the Technical University of Denmark. From the beginning, the course has been a targeted on life cycle assessment with a strong emphasis on the performance and use of life cycle assessment...... as decision support to industry and authorities. While different applications of life cycle assessments are introduced in lectures during the course, the main focus is on how to do an LCA....

  5. Off-design performance analysis of Kalina cycle for low temperature geothermal source

    International Nuclear Information System (INIS)

    Li, Hang; Hu, Dongshuai; Wang, Mingkun; Dai, Yiping

    2016-01-01

    Highlights: • The off-design performance analysis of Kalina cycle is conducted. • The off-design models are established. • The genetic algorithm is used in the design phase. • The sliding pressure control strategy is applied. - Abstract: Low temperature geothermal sources with brilliant prospects have attracted more and more people’s attention. Kalina cycle system using ammonia water as working fluid could exploit geothermal energy effectively. In this paper, the quantitative analysis of off-design performance of Kalina cycle for the low temperature geothermal source is conducted. The off-design models including turbine, pump and heat exchangers are established preliminarily. Genetic algorithm is used to maximize the net power output and determine the thermodynamic parameters in the design phase. The sliding pressure control strategy applied widely in existing Rankine cycle power plants is adopted to response to the variations of geothermal source mass flow rate ratio (70–120%), geothermal source temperature (116–128 °C) and heat sink temperature (0–35 °C). In the off-design research scopes, the guidance for pump rotational speed adjustment is listed to provide some reference for off-design operation of geothermal power plants. The required adjustment rate of pump rotational speed is more sensitive to per unit geothermal source temperature than per unit heat sink temperature. Influence of the heat sink variation is greater than that of the geothermal source variation on the ranges of net power output and thermal efficiency.

  6. Synthesis of manganese coordination polymer microspheres for lithium-ion batteries with good cycling performance

    International Nuclear Information System (INIS)

    Fei, Hailong; Liu, Xin; Li, Zhiwei; Feng, Wenjing

    2015-01-01

    Highlights: • We achieve controllable synthesis of manganese 2,5-thiophene dicarboxylate microspheres with DMF and CTABr. • We perform research on changes in morphologies and crystalline structure. • It is a new anode material for lithium-ion batteries with high capacity and good cycle stability. - Abstract: A simple and versatile method for preparation of novel manganese 2,5-thiophene dicarboxylate microspheres is developed via a surfactant-assisted solvo-thermal route, which are found to be a new high-energy anode material for lithium-ion batteries. It shows better cycling performance and higher discharge capacity than its counterpart of irregular shapes. A reversible capacity was achieved as high as 645.7 mA h g −1 after 250 cycles at a current density of 400 mA g −1 . Furthermore, the coulombic efficiency can be close to 100% even after 650 charge-discharge cycles at a current density of 500 mA g −1

  7. Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

    Science.gov (United States)

    Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

    2017-11-01

    Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Organising Life-cycles in Supply Chains: Linking Environmental Performance to Managerial Designs

    NARCIS (Netherlands)

    Hagelaar, J.L.F.; Vorst, van der J.G.A.J.; Marcelis, W.J.

    2005-01-01

    In recent years increasing attention has been given to continual environmental performance improvement. Although we support the thesis that organisations are able to continuously improve their environmental performance, we state that truly higher levels of environmental care are reached only via

  9. Improvement to the gas cycle energy generating installations with heat recuperation

    International Nuclear Information System (INIS)

    Tilliette, Zephyr.

    1977-01-01

    Improvement to the gas cycle energy generating installations with heat recuperation, comprising a heat source, supplying a fluid at high temperature and pressure, an expansion turbine, at least one recuperator fitted to the turbine outlet, a cooler and compressor in series, the compressor returning the high pressure fluid to the source after heat exchange in the recuperator with the low pressure fluid from the turbine. It is characterised in that at least one steam generator is connected to the low pressure end of the recuperator [fr

  10. POSSIBILITIES AND LIMITS OF THE CYCLE OF CONTINUOUS IMPROVEMENT -PDCA AS AN ELEMENT OF LEARNING

    Directory of Open Access Journals (Sweden)

    Celso Machado Junior

    2013-08-01

    Full Text Available The aim of this study is to investigate the possibilities and limits of the use of continuous improvement cycle, PDCA, as a tool that contributes to the development of individual learning in the organization. It is a qualitative, descriptive end uses the case study as a method. It was observed that the practice proposed by PDCA, can be used in the process of knowledge creation in line with the authors in the field, constituting a form of knowledge management within the organization, enabling the creation of tacit knowledge and its explicit transformation were not observed limits for their use.

  11. Improved Electrochemical Cycling Durability in a Nickel Oxide Double-Layered Film.

    Science.gov (United States)

    Hou, Shuai; Zhang, Xiang; Tian, Yanlong; Zhao, Jiupeng; Geng, Hongbin; Qu, Huiying; Zhang, Hangchuan; Zhang, Kun; Wang, Binsheng; Gavrilyuk, Alexander; Li, Yao

    2017-11-16

    For the first time, a crystalline-amorphous double-layered NiO x film has been prepared by reactive radio frequency magnetron sputtering. This film has exhibited improved electrochemical cycling durability, whereas other electrochromic parameters have been maintained at the required level, namely, a short coloration/bleaching time (0.8 s/1.1 s) and an enhanced transmittance modulation range (62.2 %) at λ=550 nm. Additionally, the double-layered film has shown better reversibility than that of amorphous and crystalline single-layered films. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Training Attentional Control Improves Cognitive and Motor Task Performance.

    Science.gov (United States)

    Ducrocq, Emmanuel; Wilson, Mark; Vine, Sam; Derakshan, Nazanin

    2016-10-01

    Attentional control is a necessary function for the regulation of goal-directed behavior. In three experiments we investigated whether training inhibitory control using a visual search task could improve task-specific measures of attentional control and performance. In Experiment 1 results revealed that training elicited a near-transfer effect, improving performance on a cognitive (antisaccade) task assessing inhibitory control. In Experiment 2 an initial far-transfer effect of training was observed on an index of attentional control validated for tennis. The principal aim of Experiment 3 was to expand on these findings by assessing objective gaze measures of inhibitory control during the performance of a tennis task. Training improved inhibitory control and performance when pressure was elevated, confirming the mechanisms by which cognitive anxiety impacts performance. These results suggest that attentional control training can improve inhibition and reduce taskspecific distractibility with promise of transfer to more efficient sporting performance in competitive contexts.

  13. Design, simulation and modelling of auxiliary exoskeleton to improve human gait cycle.

    Science.gov (United States)

    Ashkani, O; Maleki, A; Jamshidi, N

    2017-03-01

    Exoskeleton is a walking assistance device that improves human gait cycle through providing auxiliary force and transferring physical load to the stronger muscles. This device takes the natural state of organ and follows its natural movement. Exoskeleton functions as an auxiliary device to help those with disabilities in hip and knee such as devotees, elderly farmers and agricultural machinery operators who suffer from knee complications. In this research, an exoskeleton designed with two screw jacks at knee and hip joints. To simulate extension and flexion movements of the leg joints, bearings were used at the end of hip and knee joints. The generated torque and motion angles of these joints obtained as well as the displacement curves of screw jacks in the gait cycle. Then, the human gait cycle was simulated in stance and swing phases and the obtained torque curves were compared. The results indicated that they followed the natural circle of the generated torque in joints with a little difference from each other. The maximum displacement obtained 4 and 6 cm in hip and knee joints jack respectively. The maximum torques in hip and knee joints were generated in foot contact phase. Also the minimum torques in hip and knee joints were generated in toe off and heel off phases respectively.

  14. Impeller inlet geometry effect on performance improvement for centrifugal pumps

    International Nuclear Information System (INIS)

    Luo, Xianwu; Zhang, Yao; Peng, Junqi; Xu, Hongyuan; Yu, Weiping

    2008-01-01

    This research treats the effect of impeller inlet geometry on performance improvement for a boiler feed pump, who is a centrifugal pump having specific speed of 183 m.m 3 min -1 .min -1 and close type impeller with exit diameter of 450 mm. The hydraulic performance and cavitation performance of the pump have been tested experimentally. In order to improve the pump, five impellers have been considered by extending the blade leading edge or applying much larger blade angle at impeller inlet compared with the original impeller. The 3-D turbulent flow inside those pumps has been analyzed basing on RNG k-ε turbulence model and VOF cavitation model. It is noted that the numerical results are fairly good compared with the experiments. Based on the experimental test and numerical simulation, the following conclusions can be drawn: (1) Impeller inlet geometry has important influence on performance improvement in the case of centrifugal pump. Favorite effects on performance improvement have been achieved by both extending the blade leading edge and applying much larger blade angle at impeller inlet: (2) It is suspected that the extended leading edge have favorite effect for improving hydraulic performance, and the much larger blade angle at impeller inlet have favorite effect for improving cavitation performance for the test pump: (3) Uniform flow upstream of impeller inlet is helpful for improving cavitation performance of the pump

  15. Impeller inlet geometry effect on performance improvement for centrifugal pumps

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xianwu; Zhang, Yao; Peng, Junqi; Xu, Hongyuan [Tsinghua University, Beijing (China); Yu, Weiping [Zhejiang Pump Works, Zhejiang (China)

    2008-10-15

    This research treats the effect of impeller inlet geometry on performance improvement for a boiler feed pump, who is a centrifugal pump having specific speed of 183 m.m{sup 3}min{sup -1}.min{sup -1} and close type impeller with exit diameter of 450 mm. The hydraulic performance and cavitation performance of the pump have been tested experimentally. In order to improve the pump, five impellers have been considered by extending the blade leading edge or applying much larger blade angle at impeller inlet compared with the original impeller. The 3-D turbulent flow inside those pumps has been analyzed basing on RNG k-{epsilon} turbulence model and VOF cavitation model. It is noted that the numerical results are fairly good compared with the experiments. Based on the experimental test and numerical simulation, the following conclusions can be drawn: (1) Impeller inlet geometry has important influence on performance improvement in the case of centrifugal pump. Favorite effects on performance improvement have been achieved by both extending the blade leading edge and applying much larger blade angle at impeller inlet: (2) It is suspected that the extended leading edge have favorite effect for improving hydraulic performance, and the much larger blade angle at impeller inlet have favorite effect for improving cavitation performance for the test pump: (3) Uniform flow upstream of impeller inlet is helpful for improving cavitation performance of the pump

  16. Benchmarking and performance improvement at Rocky Flats Technology Site

    International Nuclear Information System (INIS)

    Elliott, C.; Doyle, G.; Featherman, W.L.

    1997-03-01

    The Rocky Flats Environmental Technology Site has initiated a major work process improvement campaign using the tools of formalized benchmarking and streamlining. This paper provides insights into some of the process improvement activities performed at Rocky Flats from November 1995 through December 1996. It reviews the background, motivation, methodology, results, and lessons learned from this ongoing effort. The paper also presents important gains realized through process analysis and improvement including significant cost savings, productivity improvements, and an enhanced understanding of site work processes

  17. Back-end fuel cycle efficiencies with respect to improved uranium utilization

    International Nuclear Information System (INIS)

    Kuczera, B.; Hennies, H.H.

    1983-01-01

    The world-wide nuclear power plant (NPP) capacity is at present 160 GW(e). If one adds the power stations under construction and ordered, a plant capacity of approximately 480 GW(e) is obtained for 1990, with the share of LWRs making up more than 80%. A modern LWR consumes in the open fuel cycle about 4400 metric tonnes of natural uranium per GW(e), assuming a lifetime of 30 years and a load factor of 70%. Considering the natural uranium reserves known at present and exploitable under economic conditions, it can be conveniently estimated that, with the present NPP capacity extension perspective, the natural uranium resources may be exhausted in a few decades. This trend can be counteracted in a flexible manner by various approaches in fuel cycle technology and strategy: (i) by steady further development of the established LWR technology the uranium consumption can be reduced by about 15%; (ii) closing the nuclear fuel cycle on the basis of LWRs (i.e. thermal uranium and plutonium recycling) implies up to 40% savings in natural uranium consumption; (iii) more recent considerations include the advanced pressurized water reactor (APWR). The APWR combines the proven PWR technology with a newly developed tight lattice core with greatly improved conversion characteristics (conversion ratio = 0.90 to 0.95). In terms of uranium utilization, the APWR has an efficiency three to five times higher than a PWR; (iv) Commercial introduction of FBR systems results in an optimal utilization of uranium which, at the same time, guarantees the supply of nuclear fuel well beyond the present century. For a corresponding transition period an energy supply system can be conceived which relies essentially on extended back-end fuel cycle capacities. These would facilitate a symbiosis of PWR, APWR and FBR, characterized by high flexibility with respect to long-term developments on the energy market. (author)

  18. Preliminary design and off-design performance analysis of an Organic Rankine Cycle for geothermal sources

    International Nuclear Information System (INIS)

    Hu, Dongshuai; Li, Saili; Zheng, Ya; Wang, Jiangfeng; Dai, Yiping

    2015-01-01

    Highlights: • A method for preliminary design and performance prediction is established. • Preliminary data of radial inflow turbine and plate heat exchanger are obtained. • Off-design performance curves of critical components are researched. • Performance maps in sliding pressure operation are illustrated. - Abstract: Geothermal fluid of 90 °C and 10 kg/s can be exploited together with oil in Huabei Oilfield of China. Organic Rankine Cycle is regarded as a reasonable method to utilize these geothermal sources. This study conducts a detailed design and off-design performance analysis based on the preliminary design of turbines and heat exchangers. The radial inflow turbine and plate heat exchanger are selected in this paper. Sliding pressure operation is applied in the simulation and three parameters are considered: geothermal fluid mass flow rate, geothermal fluid temperature and condensing pressure. The results indicate that in all considered conditions the designed radial inflow turbine has smooth off-design performance and no choke or supersonic flow are found at the nozzle and rotor exit. The lager geothermal fluid mass flow rate, the higher geothermal fluid temperature and the lower condensing pressure contribute to the increase of cycle efficiency and net power. Performance maps are illustrated to make system meet different load requirements especially when the geothermal fluid temperature and condensing pressure deviate from the design condition. This model can be used to provide basic data for future detailed design, and predict off-design performance in the initial design phase

  19. Burnup performance of OTTO cycle pebble bed reactors with ROX fuel

    International Nuclear Information System (INIS)

    Ho, Hai Quan; Obara, Toru

    2015-01-01

    Highlights: • A 300 MW t Small Pebble Bed Reactor with Rock-like oxide fuel is proposed. • Using ROX fuel can achieve high discharged burnup of spent fuel. • High geological stability can be expected in direct disposal of the spent ROX fuel. • The Pebble Bed Reactor with ROX fuel can be critical at steady state operation. • All the reactor designs have a negative temperature coefficient. - Abstract: A pebble bed high-temperature gas-cooled reactor (PBR) with rock-like oxide (ROX) fuel was designed to achieve high discharged burnup and improve the integrity of the spent fuel in geological disposal. The MCPBR code with a JENDL-4.0 library, which developed the analysis of the Once-Through-Then-Out (OTTO) cycle in PBR, was used to perform the criticality and burnup analysis. Burnup calculations for eight cases were carried out for both ROX fuel and a UO 2 fuel reactor with different heavy-metal loading conditions. The effective multiplication factor of all cases approximately equalled unity in the equilibrium condition. The ROX fuel reactor showed lower FIFA than the UO 2 fuel reactor at the same heavy-metal loading, about 5–15%. However, the power peaking factor and maximum power per fuel ball in the ROX fuel core were lower than that of UO 2 fuel core. This effect makes it possible to compensate for the lower-FIFA disadvantage in a ROX fuel core. All reactor designs had a negative temperature coefficient that is needed for the passive safety features of a pebble bed reactor

  20. Development of Thermal Performance Analysis Computer Program on Turbine Cycle of Yoggwang 3,4 Units

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.Y.; Choi, K.H.; Jee, M.H.; Chung, S.I. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    The objective of the study ''Development of Thermal Performance Analysis Computer Program on Turbine Cycle of Yonggwang 3,4 Units'' is to utilize computerized program to the performance test of the turbine cycle or the analysis of the operational status of the thermal plants. In addition, the result can be applicable to the analysis of the thermal output at the abnormal status and be a powerful tool to find out the main problems for such cases. As a results, the output of this study can supply the way to confirm the technical capability to operate the plants efficiently and to obtain the economic gains remarkably. (author). 27 refs., 73 figs., 6 tabs.