Articles de revues : « COP IMPROVEMENT »

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Liu, Ying Fu, et Guang Ya Jin. « Vortex Tube Expansion Two-Stage Transcritical CO₂ Refrigeration Cycle ». Advanced Materials Research 516-517 (mai 2012) : 1219–23. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.1219.

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Use of vortex tube as an expansion device in transcritical CO2 cycle could reduce the throttle loss and improve the coefficient of performance. In this paper, a vortex tube expansion two-stage transcritical CO2 refrigeration cycle(VTTC) is established and compared to that of the two-stage transcritical CO2 refrigeration cycle with throttle valve(TVTC). Thermodynamic analysis results indicate that there is also an optimum heat rejection pressure for the vortex tube cycle, and the COP improvement is 2.4%~16.3% at given conditions. Decrease in evaporation temperature or increase in gas-cooler outlet temperature decrease the COP, but the COP improvement will increase. The effect of cold mass fraction on the COP is negligible, but the COP improvement will increase fast with the increase of cold mass fraction.

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Xie, Ying Bai, Kui Kui Cui, Zhi Chao Wang et Jian Lin Liu. « CO₂ Trans-Critical Two Stage Compression Refrigeration Cycle with Vortex Tube ». Applied Mechanics and Materials 52-54 (mars 2011) : 255–60. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.255.

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The paper analyses CO2 trans-critical two stage compression refrigeration cycle with vortex tube expansion by thermodynamics method. And compare with CO2 trans-critical two stage compression refrigeration cycle with expansion value. The results show that in the calculated conditions of the paper, the performance of the cycle with vortex tube improves 2.4%~16.3% than the cycle with expansion value. The optimal discharge pressure maximizing COP of the cycle with vortex tube exists. With lower evaporating temperature or higher gas cooler exit temperature, COP of system decreases and COP improvement increases. The effect of cold fluid mass fraction on COP is not significant, but COP improvement increases more quickly with cold gas mass fraction increasing.

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Liu, Yefeng, Ying Sun et Danping Tang. « Analysis of a CO2 Transcritical Refrigeration Cycle with a Vortex Tube Expansion ». Sustainability 11, n^o 7 (4 avril 2019) : 2021. http://dx.doi.org/10.3390/su11072021.

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A carbon dioxide (CO2) refrigeration system in a transcritical cycle requires modifications to improve the coefficient of performance (COP) for energy saving. This modification has become more important with the system’s more and more widely used applications in heat pump water heaters, automotive air conditioning, and space heating. In this paper, a single vortex tube is proposed to replace the expansion valve of a traditional CO2 transcritical refrigeration system to reduce irreversible loss and improve the COP. The principle of the proposed system is introduced and analyzed: Its mathematical model was developed to simulate and compare the system performance to the traditional system. The results showed that the proposed system could save energy, and the vortex tube inlet temperature and discharge pressure had significant impacts on COP improvement. When the vortex tube inlet temperature was 45 °C, and the discharge pressure was 9 MPa, the COP increased 33.7%. When the isentropic efficiency or cold mass fraction of the vortex tube increased, the COP increased about 10%. When the evaporation temperature or the cooling water inlet temperature of the desuperheater decreased, the COP also could increase about 10%. The optimal discharge pressure correlation of the proposed system was established, and its influences on COP improvement are discussed.

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ITOU, Hiroshi, Hiroyuki NANBU et Hiromi MORI. « COP improvement for encapsulated ice storage system ». Proceedings of the Symposium on Environmental Engineering 2004.14 (2004) : 340–43. http://dx.doi.org/10.1299/jsmeenv.2004.14.340.

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Sarkar, Jahar. « Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids ». Thermal Science 19, n^o 1 (2015) : 109–18. http://dx.doi.org/10.2298/tsci120702121s.

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The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

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Garimella, S. « Absorption Heat Pump Performance Improvement Through Ground Coupling ». Journal of Energy Resources Technology 119, n^o 4 (1 décembre 1997) : 242–49. http://dx.doi.org/10.1115/1.2794997.

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The present study investigates the improvement in the performance of an absorption heat pump for residential space-conditioning due to the use of the ground as the heat source in the heating mode and the heat sink in the cooling mode. A baseline air-coupled single-effect ammonia-water heat pump is first designed to deliver 10.55 kW (36,000 Btu/h) of cooling load at the ARI rating conditions. Particular attention is paid to incorporating many realistic details of an operating system such as fuel combustion efficiencies of the burner, nonequilibrium conditions, and moist air processes in the air-coupled heat exchangers. A range of parametric studies is also conducted to investigate the variation in performance of this system with ambient conditions in the heating and cooling modes. The same system is then analyzed in a ground-coupled configuration. The instantaneous COP for the ground-coupled system is compared with the COP of the air-coupled system as a function of the time of the year and the corresponding variations in ambient and ground temperatures using 30-yr average climate data for various locations from the National Weather Service. Improvements in COP of up to 20 percent over the air-coupled system values (cooling mode COP of 0.495 at 35°C (95°F) and heating mode COP of 1.20 at 8.33°C (47°F)) are demonstrated in diverse geographic locations with widely varying heating and cooling loads. These improvements indicate that an efficient ground-coupled heat pump could be developed for residential space-conditioning applications using simple thermodynamic cycles and existing technology for the heat and mass exchange components.

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Çoban, Fahriye, Beliz Belgen Kaygısız et Ferda Selcuk. « Effect of clinical Pilates training on balance and postural control in patients with Parkinson’s disease : a randomized controlled trial ». Journal of Comparative Effectiveness Research 10, n^o 18 (décembre 2021) : 1373–83. http://dx.doi.org/10.2217/cer-2021-0091.

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Background: Clinical pilates exercises have been shown to improve balance. Our study aims to compare effects of clinical Pilates and conventional physiotherapy exercises on balance and postural control in Parkinson’s disease patients. Materials & methods: Forty patients were randomly assigned into either clinical Pilates (CLP) or conventional physiotherapy (COP) group. Exercises were performed twice a week for 8 weeks. Balance, lower-extremity strength, fall risk and functional mobility were assessed at the beginning and end of the exercise period. Results: All measurements indicated significant increase in two groups (p < 0.05). Compared with the COP group, the CLP group showed significant improvement in dynamic balance values (p < 0.05). Conclusion: CLP was as effective as COP, with better dynamic balance results, and could be used in rehabilitation for patients with Parkinson’s disease. Clinical trial registration number: NCT04063605 .

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Mahata, G., et S. Sardar. « Evaluation of elite sugarcane clones/varieties against red rot disease (Colletotrichum falcatum) and their suitability in crop improvement programme ». Agricultural Science and Technology 14, n^o 1 (mars 2022) : 28–33. http://dx.doi.org/10.15547/ast.2022.01.004.

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Abstract. To manage red rot disease in sugarcane, several methods like use of bio-control agents, hot water and hot air treatment of setts, chemical fungicides, various cultural practices like use of disease free setts, rouging, crop rotation, irrigation management, avoiding rationing, etc. are practised. But none of the practices are able to control the disease. The most viable strategy is to manage through host plant resistance. Thus, a field experiment was conducted for two consecutive years during 2019 and 2020 at the Research Farm of Sugarcane Research Station, Bethuadahari (West Bengal), India to evaluate some elite sugarcane clones/varieties against red rot disease. The elite clones/varieties were laid out in Completely Randomized Block Design with a plot size of 2R x 6m x 0.90m with 2 replications and two red rot pathotypes Cf 07 and Cf 08 were used for artificial inoculation in plug and nodal method. The experiment revealed that the sugarcane clones CoP 16436, CoP 16437, CoP 16438, CoLk 16466, CoLk 16467, CoLk 16468, CoSe 16451, CoP 16439, CoP 16440, BO 156, CoLk 16469, CoLk 16470, CoLk 16471, CoSe 16452, CoSe 16453, CoSe 16454, CoP 17436, CoP 17437, CoP 17438, CoP 17440, CoP 17441, CoSe 17451, CoSe 16455, CoSe 16456, CoP 17444, CoP 17446 and CoSe 17452 were found as moderately resistant (MR) in plug method and resistant (R) in nodal method to both pathotypes and can be used for further evaluation in subsequent varietal developmental as well as breeding programme. The popular sugarcane varieties, namely CoLk 94184, CoSe 01421, BO 91, CoP 9301 and CoP 06436 were found as moderately resistant (MR) in plug method and resistant (R) in nodal method and can be continued for commercial cultivation as well as red rot breeding programme. As the existing popular variety CoSe 95422 was found moderately susceptible (MS) in plug method and susceptible (S) in nodal method to Cf 07 and Cf 08 red rot pathotypes, thus the variety must be discarded from commercial cultivation with immediate effect.

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Chorowski, Maciej, Piotr Pyrka, Zbigniew Rogala et Piotr Czupryński. « Experimental Study of Performance Improvement of 3-Bed and 2-Evaporator Adsorption Chiller by Control Optimization ». Energies 12, n^o 20 (17 octobre 2019) : 3943. http://dx.doi.org/10.3390/en12203943.

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The main challenge facing adsorption cooling technology is low Coefficient of Performance (COP), which becomes a key factor of the commercialization of this technology. This paper presents the results of modifications, aiming to increase COP, applied to the control software of a prototype three-bed two-evaporator adsorption chiller. Changes were mainly related to the sequence of the switching valves and had no influence on the hardware of the chiller. The sequence changes enabled the introduction of heat recovery and mass regeneration. Moreover, the precooling process was improved. The applied modifications not only resulted in significant improvement of the chiller’s COP, but also improved the cooperation adsorption unit heating source, which is of great importance in case of district heating supply. The improvement was also observed concerning such operational aspects as noise and vibrations. In the authors’ opinion, the presented modifications can be introduced to most exploited adsorption chillers and could potentially lead to similar improvements in performance.

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Liu, Xi, Yueling Li, Kunyu Zhuang, Ruansong Fu, Shi Lin et Xuelai Li. « Performance Study and Efficiency Improvement of Ice Slurry Production by Scraped-Surface Method ». Applied Sciences 9, n^o 1 (26 décembre 2018) : 74. http://dx.doi.org/10.3390/app9010074.

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In this study, the performance of ice slurry production by scraped-surface method was experimentally investigated. Temperature change characteristics, ice packing fraction (IPF) of ice slurry, power consumption of scraping system and coefficient of performance (COP) were measured by varying the concentration of sodium chloride solution, scraping speed, and solution flow rate. The effect of nanosilica on efficiency of ice slurry production was also studied. The results showed that scraping power consumption accounted for only a small proportion (about 5%) of the total power consumption of the system. An increase in the concentration of sodium chloride caused a decrease in the IPF and a decrease in the COP of the system. With the solution flow rate at 1.3 m3/h and scraping speed at 13 rpm, the maximum COP (2.43) was obtained. Furthermore, the addition of nanosilica had a significant effect on improving the system COP.

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Wazni, Liquaa, Wendy Gifford, Christina Cantin et Barbara Davies. « A community of practice for graduate students in health sciences ». Higher Education Evaluation and Development 15, n^o 2 (29 avril 2021) : 135–51. http://dx.doi.org/10.1108/heed-10-2020-0037.

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PurposeThe aim of this study was to describe the experiences of graduate students who participated in the community of practice (CoP) and identify areas for improvement to support academic success.Design/methodology/approachIn total, 19 graduate students engaged in a CoP to facilitate social interactions, knowledge sharing and learning within a culture of scholarship. A descriptive qualitative research study was conducted using semistructured interviews with eight participants who had attended the CoP meeting.FindingsAll participants were from the School of Nursing and perceived the CoP to be beneficial, particularly international students who had challenges in adapting to new academic and social environments. Areas for improvement include creating a group structure that enhances belonging and learning.Originality/valueThis is the first CoP that was implemented at the Faculty of Health Sciences at the authors’ university. It has been the authors’ experience that a CoP can benefit graduate students through networking, knowledge sharing, social support and learning. The finding of this research will be used to inform a new CoP to address the needs of graduate students. The authors will be adapting the CoP to the current context that includes a virtual platform during the COVID-19 pandemic and will include content specific for international students.

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Mishra, Shubham, et Jahar Sarkar. « Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system ». Archives of Thermodynamics 37, n^o 4 (1 décembre 2016) : 55–72. http://dx.doi.org/10.1515/aoter-2016-0027.

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AbstractPerformance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene) is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP) for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%), which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle). Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

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Dizaji, Hamed Sadighi, Samad Jafarmadar et Shahram Khalilarya. « Novel experiments on COP improvement of thermoelectric air coolers ». Energy Conversion and Management 187 (mai 2019) : 328–38. http://dx.doi.org/10.1016/j.enconman.2019.03.025.

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ASANO, Takashi, et Nohiro MORITA. « F208 COP improvement of heat-pump type hot-water storage and supply. : COP improvement in thermal storage driving at nighttime of winter. » Proceedings of the National Symposium on Power and Energy Systems 2010.15 (2010) : 481–82. http://dx.doi.org/10.1299/jsmepes.2010.15.481.

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KHAN, MD IMRAN HOSSEN, et HASAN M. M. AFROZ. « EXPERIMENTAL INVESTIGATION OF PERFORMANCE IMPROVEMENT OF HOUSEHOLD REFRIGERATOR USING PHASE CHANGE MATERIAL ». International Journal of Air-Conditioning and Refrigeration 21, n^o 04 (décembre 2013) : 1350029. http://dx.doi.org/10.1142/s2010132513500296.

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An experimental investigation has been carried out to know about the performance improvement of a household refrigerator using phase change material (PCM). PCMs are used as latent heat thermal storage system to enhance the heat transfer of the evaporator. PCM is located behind the five sides of the evaporator cabinet in which the evaporator coil is immersed. Water (melting point 0°C) and Eutectic solutions (melting point −5°C) are used as PCMs for this experiment at different thermal loads. Depending on the types of PCM and thermal load, around 20–27% COP improvement of the refrigeration cycle has been observed with PCM with respect to without PCM. With the increase of the quantity of PCM (0.003 to 0.00425 m3) COP increases about 6%. Between two different PCMs the COP improvement for Eutectic solution is higher than Water. The experimental results with PCM confirm that, depending on the thermal load and the types of PCM average compressor running time per cycle is reduced significantly and it is found about 2–36% as compared to without PCM.

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Mishra, Anupam. « A Review of Literature on Various Techniques of COP Improvement in Vapor Compression Refrigeration System ». International Journal for Research in Applied Science and Engineering Technology 9, n^o 11 (30 novembre 2021) : 1753–59. http://dx.doi.org/10.22214/ijraset.2021.39102.

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Abstract: This review paper is a study on various methods of performance improvement in domestic refrigeration systems, based on the vapor compression refrigeration VCRS cycle. Here air-cooled, water-cooled, fog cooled, evaporatively cooled condensers and nano-fluid lubricant /coolant methods their working and efficiency are reviewed, compared, analyzed and presented. The paper inspects the work done by different researchers for the maximization of heat loss from condenser & compressor and bringing about necessary modifications to reduce the overall power consumption of domestic refrigerators by improving Coefficient of Performance (COP). Numerous works have been done on improving the heat dissipation capacity of condenser but using nano-fluid in lubricant base as refrigerant and in the compressor shell as coolant is a new technology. Nano-fluid increase heat transfer due the high conductivity nano particles. It has been observed that water cooled condensers and compressors with nano-lubricants/coolants give the best performance improvements but they suit better for big or large refrigeration systems like centralized air conditioning systems or cold storage warehousing, whereas air cooled and evaporative condensers are optimal for small scale or low power appliances like domestic refrigerators, water coolers or split air conditioners to reduce overall power consumption by increasing the COP. Keywords: Refrigeration system, COP improvement, Condenser, Water mist, Evaporative cooling, Nano-fluid coolant, VCRS cycle.

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Sarkar, J. « Performance characteristics of natural-refrigerants- based ejector expansion refrigeration cycles ». Proceedings of the Institution of Mechanical Engineers, Part A : Journal of Power and Energy 223, n^o 5 (22 mai 2009) : 543–50. http://dx.doi.org/10.1243/09576509jpe753.

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The thermodynamic analyses and comparison of three natural-refrigerants-based vapour compression refrigeration cycles (ammonia, isobutane, and propane) are presented in this article using a constant pressure mixing ejector as an expansion device. Optimization of the area ratio of the ejector is done based on maximum cooling coefficient of performance (COP) and performance improvement for different operating conditions. The effect of using an internal heat exchanger is studied as well. Results show that optimum area ratio and cooling COP increases with a decrease in cycle temperature lift, whereas the COP improvement over basic expansion cycle increases with the increase in cycle temperature lift. Study shows that the optimum parameters, as well as performance using the ejector as an expansion device, are strongly dependent on the refrigerant properties as well as the operating conditions. The optimum area ratio is maximum for ammonia and minimum for propane, whereas maximum cooling COPs are similar. Using the ejector as an expansion device, propane yields a maximum COP improvement of 26.1 per cent followed by isobutane (22.8 per cent) and ammonia (11.7 per cent) for studies ranges. The effect of using an internal heat exchanger in the ejector expansion refrigeration cycle is found to be not profitable.

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Ferrara, G., L. Ferrari, D. Fiaschi, G. Galoppi, S. Karellas, R. Secchi et D. Tempesti. « A Small Power Recovery Expander for Heat Pump COP Improvement ». Energy Procedia 81 (décembre 2015) : 1151–59. http://dx.doi.org/10.1016/j.egypro.2015.12.140.

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ISHUGAH, FRED T., RUZHU WANG, LIWEI WANG et ZISHENG LU. « PERFORMANCE IMPROVEMENT OF AN ADSORPTION CHILLER USING COMPOSITE ADSORBENT, SILICA GEL IMPREGNATED WITH LITHIUM CHLORIDE, PAIRED WITH METHANOL AS THE ADSORBATE ». International Journal of Air-Conditioning and Refrigeration 22, n^o 02 (29 avril 2014) : 1440003. http://dx.doi.org/10.1142/s2010132514400033.

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This study aimed at analyzing different operation strategies to improve the performance of a new type adsorption chiller employing a novel composite adsorbent, silica gel impregnated with lithium chloride, paired with methanol as the adsorbate. The chiller's experimental test results showed an average Specific Cooling Power (SCP) and Coefficient of Performance (COP) of 286 W/kg and 0.48, respectively. This was when the average hot water inlet temperature, cooling water inlet temperature, and chilled water inlet temperature were 83°C, 26°C and 15°C, respectively. In addition, the corresponding mass flow rates were 0.22, 0.39 and 0.09 kg/s, respectively. Despite the fact that the average SCP and COP, were rather satisfactory, analysis of experimental results conducted with different cycle times, inlet hot water temperatures, and hot water flow rates showed that a much better performance could be achieved. Experimental results indicated the following: (1) the COP increased while the SCP decreased with increased cycle time, (2) both the COP and the SCP increased with increase in heat and mass recovery time to an optimal time then started to decrease as heat and mass recovery time increased beyond the optimal time, (3) both the cooling power and COP generally increased with increase in inlet hot water temperature at a relatively higher value from 60°C to about 90°C beyond which the incremental value started diminishing, and, (4) increase in mass flow rates produced higher cooling power with decreased COP while decrease in mass flow rates of hot water produced lower cooling power with increased COP. This paper therefore recommends an adsorption/desorption time, heat and mass recovery time, inlet hot water temperature, and hot water mass flow rate of 780 s, 60 s, 83°C, and 0.22 kg/s as appropriate to give the best chiller performance for refrigeration.

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Yang, Xiaorong, Min Xie, Lu Tan, Taomei Li et Xiangdong Tang. « Case report of new-onset obstructive sleep apnea after carbon monoxide poisoning ». Journal of International Medical Research 49, n^o 2 (février 2021) : 030006052199222. http://dx.doi.org/10.1177/0300060521992228.

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Obstructive sleep apnea (OSA) is characterized by repetitive intermittent oxygen desaturation during sleep. Carbon monoxide poisoning (COP) is the second most common cause of death among non-medicinal poisonings, and oxygen therapy is the current standard of treatment for COP. We herein report a case of a 50-year-old woman diagnosed with severe OSA associated with COP. Both the OSA and COP gradually resolved by automatic continuous positive airway pressure (CPAP) therapy. New OSA symptoms appeared following the development of delayed encephalopathy after acute COP (DEACMP) 3 weeks later. Severe OSA was diagnosed 76 days after COP with an apnea–hypopnea index of 66 events/hour, and CPAP therapy was immediately administered. The patient’s DEACMP symptoms and OSA both improved with CPAP therapy (her apnea–hypopnea index decreased to 32.4 and 16.5 events/hour at 161 and 204 days after COP, respectively). To our knowledge, this is the first case report of OSA caused by COP based on the occurrence and disappearance of OSA symptoms and laboratory findings associated with the emergence and improvement of DEACMP.

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Wellid, Ismail, Kasni Sumeru, Abdul Aziz Azhar, Nasution Henry et A. M. Abioye. « Performance Analysis of Hydrocarbon Mixture to Replace R134a in an Automotive Air Conditioning System ». Applied Mechanics and Materials 554 (juin 2014) : 444–48. http://dx.doi.org/10.4028/www.scientific.net/amm.554.444.

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At present, most air conditioners in an automotive use R134a as working fluid. Due to the negative impact on the environment, i.e. global warming, the refrigerant must be replaced by environmental friendly working fluid. Hydrocarbons are natural fluids, no effect on the climate, inexpensive and readily available. The hydrocarbon mixture used in the present study is R436A, composed of R290 (propane) and R600a (isobutane) with a mass ratio of 56/44. The results show that the drop-in substitute from R134a to R436A reduced COP by 4.84, 4.74 and 4.64% for the condenser temperature of 40, 45 and 50°C, respectively. To generate COP improvement on the drop-in substitute, subcooling was carried out, and results show that the COP improvement was 4.42, 5.20 and 6.09% for the condenser temperature of 40, 45 and 50°C, respectively.

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Sivalingam, Suyambazhahan, Sakthivel Thirumalai Gopal, Vivek Pandey et Mohanram Parthiban. « Experimental Analysis of Performance Improvement of a Modified Vapour Absorption System (VAS-GAX) for Cooling Applications ». International Journal of Heat and Technology 39, n^o 6 (31 décembre 2021) : 1878–86. http://dx.doi.org/10.18280/ijht.390623.

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Experiments on an enhanced “Generator-Absorber-Heat Exchanger” (GAX) Vapour Absorption System (VAS) for cooling purposes were carried out using water-ammonia in present study. The new experimental setup was fabricated using modern and complex technologies for the GAX absorption system which includes tiny heat exchangers, allowing the system to be both compact and efficient. The coefficient of performance (COP) of a system was analyzed for different temperatures of Generator, Condenser, Evaporator and Absorber. The results show that the maximum performance (COP=0.63) is achieved at 25℃ Generator temperature. The system has a low carbon footprint because it does not use effluent water or tower electricity and invention enables the recovery of hot air, which may then be used for several drying applications, including agricultural drying, resulting in a fully cascaded system with a three-fold increase in Coefficient of Performance (COP). A modified VAS-GAX absorption system in present analysis be a good fit for high-performance modern cooling applications.

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McPhail, Emma, et Ian Yanson. « The improvement of the quality of medical reviews of patients in seclusion in Rampton Hospital ». BJPsych Open 7, S1 (juin 2021) : S333. http://dx.doi.org/10.1192/bjo.2021.874.

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AimsImprove and standardise the quality of medical seclusion reviews (MSRs).Acknowledge existing good practise.Highlight areas for improvement.Improve the awareness of doctors performing MSRs of the requirements in the Mental Health Act Code of Practice (MHA CoP)BackgroundMSRs are an essential clinical tool to ensure safe and consistent patient care. Patients detained in seclusion can be at heightened risk of poor mental and physical health, in addition to being a risk to themselves and others. There is clear guidance in the MHA CoP regarding what areas require to be covered in a MSR.MethodA retrospective audit of all MSRs in September 2019 across all patients within all directorates within Rampton Hospital was undertaken. 281 inpatients were identified within Rampton Hospital, and 61 of these patients were found to have had seclusion in September 2019. A total of 439 MSRs were identified for these patients.The standard applied was the MHA CoP guidance for MSRs: 1)MSRs should be conducted in person, and should include:2)Review of physical health3)Review of psychiatric health4)Assessment of the adverse effects of medication5)Review of observations required6)Reassessment of medication prescribed7)Assessment of the patient's risk to others8)Assessment of the patient's risk of self-harm9)Assessment of the need for continuing seclusion100% compliance with targets or a reason why it was not possible was expected to be documented.ResultThe results show there is a large variation in compliance with the MHA CoP. The area with the highest compliance was the completion of reviews in person-(99.3%). The criterion with the average worst compliance was whether the need for physical observations was reviewed-(4.3%). Physical health was reviewed in 86.1% of cases, in contrast to psychiatric health at 38.3%. The adverse effects of medication and reassessment of medication prescribed were recorded in only 8.9%. The risk from the patient to others was recorded in 25.3%, whereas risk to self was recorded in 10.7%. The need for continuing seclusion was recorded in 72.7%.ConclusionThe quality of MSRs at Rampton Hospital is currently inadequate. Improvement in practice is required to meet accepted standards and ensure safe, consistent patient care. Ways to improve this are being considered, including improving the knowledge of the MHA CoP and providing a MSR template.

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Serevina, Vina, Sumeru et Henry Nasution. « Effect of Refrigerant on the Exergy Loss and Performance in Air Conditioner Using Ejector as Expansion Device ». Advanced Materials Research 1125 (octobre 2015) : 531–35. http://dx.doi.org/10.4028/www.scientific.net/amr.1125.531.

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This paper presents a numerical approach to determine the exergy loss in an air conditioner using (A/C) R22 and R290 as working fluid. The exergy loss should be minimized in order to increase the performance of the air conditioner. The present study investigates the A/C with cooling capacity of 2.4 kW. The results show that the total exergy loss of R290 is lower than that of R222, viz. 0.667 and 0.857 kW, respectively. This indicates that the use of R290 in the air conditioner using ejector as expansion device will generate a better COP improvement than that of R22. In addition, energy analysis shows that the COP improvements using R290 is higher than that of R22, for instance, 12.24 and 8.15% for R290 and R22, respectively, at the ambient temperature of 35°C.

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BYKOVSKII, P. V., et M. A. SHERMAN. « Evaluation of the effectiveness of alpha training for acute nonspecific neck and lower back pain using stabilometry ». Practical medicine 18, n^o 5 (2020) : 156–62. http://dx.doi.org/10.32000/2072-1757-2020-5-156-162.

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Impaired postural control and balance and abnormal compensatory postural strategies are one of the pathogenetic mechanisms of development and chronicity of acute nonspecific neck and lower back pain. Stabilometry is a common and objective diagnostic technique that evaluates the postural control. The purpose is to determine the effectiveness of the alpha neurofeedback training for acute nonspecific neck and lower back pain, using the stabilometry. Material and methods. The study included 60 patients with acute nonspecific vertebrogenic pain. The patients were divided into two equal groups (30 people in each group) by random sampling depending on the treatment protocol. The neurofeedback technique and basic therapy was applied for patients of the main group while 30 patients of the control group had only basic therapy applied to them. All measurements were performed before and after treatment. Postural control was assessed using computerized posturography (stabilometry). Postural variables examined were the centre of pressure (CoP) location, CoP average sway, total CoP area sway, and CoP sway velocity. The effectiveness of treatment was assessed by the dynamics of postural stability, the pain score (VAS), the anxiety score (SCL-90-R) and the alpha rhythm index. Results. The intervention group displayed significant (p < 0,05) improvement in postural stability at the end of treatment. There were significant differences between the intervention and control groups in CoP average sway and total CoP area sway. Both groups exhibited a decrease in anxiety scale. Conclusions. The alpha neurofeedback training yielded improvements in posturography and pain outcomes. Our study also confirms the applicability of stabilometry in evaluating postural instability in patients with nonspecific neck and lower back pain.

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Shogbon, Angela O., Jenna Hap, Robin Dretler et Anant G. Dalvi. « Cryptogenic Organizing Pneumonia During Adjuvant Chemotherapy With Oxaliplatin, 5-Fluorouracil, and Leucovorin (FOLFOX) for Colon Cancer ». Journal of Pharmacy Practice 26, n^o 1 (25 juillet 2012) : 62–66. http://dx.doi.org/10.1177/0897190012451929.

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Lung disease associated with FOLFOX (oxaliplatin/5-fluorouracil/leucovorin) chemotherapy is uncommon. We describe a case of cryptogenic organizing pneumonia (COP) occurring in a 78-year-old woman after receiving 2 cycles of modified FOLFOX6 as adjuvant chemotherapy for treatment of resected nonmetastatic colon cancer. This patient presented with respiratory symptoms including cough with scant clear sputum and wheezing on day 10 of the second cycle of mFOLFOX6. Despite therapy with systemic antibiotics and supplemental oxygen, she had a steady and relentless progression of her respiratory symptoms and status, with chest radiographs revealing progressive bilateral pulmonary infiltrates. Further chest radiograph evaluation demonstrated findings consistent with COP. Antibiotics were discontinued and methylprednisolone sodium succinate initiated as the mainstay of management for COP. The patient required a higher dose of methylprednisolone sodium succinate than typical for initial response with doses up to 3 mg/kg per d leading to prompt improvement in her respiratory symptoms and function and declining need for supplemental oxygen therapy. Chest radiographs also showed improvement. The Naranjo adverse drug reaction probability scale indicated a probable relationship (score of 5) between the patient’s COP and the FOLFOX chemotherapy. Clinicians should be aware of the potential for this uncommon, yet severe adverse reaction associated with the FOLFOX chemotherapy.

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Dimala, Christian Akem, Urvi Patel, Benjamin Lloyd, Anthony Donato, William B. Kimmel, Robert Hallowell et Caitlyn Moss. « A Case Report of Steroid-Resistant Cryptogenic Organizing Pneumonia Managed with Intravenous Immunoglobulins ». Case Reports in Pulmonology 2021 (15 novembre 2021) : 1–7. http://dx.doi.org/10.1155/2021/9343491.

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Fewer than ten reported cases of cryptogenic organizing pneumonia (COP) have been managed with intravenous immunoglobulins (IVIg). We report a case of a 72-year-old man who presented with a worsening cough and diffuse opacities on chest radiograph. Following no improvement with antibiotics and negative complementary investigations for infectious, malignant, and autoimmune etiologies, COP was confirmed on lung biopsy. Due to continued clinical deterioration despite high-dose steroids and new severe steroid-induced hallucinations, the patient was placed on intravenous immunoglobulins (IVIg) and mycophenolate mofetil and made a satisfactory recovery. IVIg should be considered as an important steroid-sparing alternative in patients with COP.

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Roonprasang, Kiattisak, et Eakasit Sritham. « Feasibility study on using evaporator condensate to subcool refrigerant in a vapor-compression refrigeration system ». MATEC Web of Conferences 192 (2018) : 03055. http://dx.doi.org/10.1051/matecconf/201819203055.

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A computer simulation based on MATLAB was developed to investigate the effectiveness of using evaporator condensate to subcool refrigerants in a vapor-compression refrigeration system. Three different types of refrigerant including R22, R410a, and R134a were studied. The simulation clearly showed the effectiveness of the technique to subcool refrigerant using evaporator condensate. Throughout the RH range of surrounding in this study, 40%-100%RH, the vapor-compression model system using R22 as a refrigerant provided the highest COP linearly ranging from 3.40 to 3.76. The greatest improvement in COP was found in the model system with R410a where the COP values increased by 3.33% to 15.36.

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Budinsky, Tomas, Peter Brooks et David Barton. « A New Analytical Model of the Brake Pad for Improved Calculation of the Centre of Pressure and Friction Coefficient in A Multi-Piston Disc Brake ». International Journal of Engineering & ; Technology 7, n^o 3.17 (1 août 2018) : 54. http://dx.doi.org/10.14419/ijet.v7i3.17.16623.

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In recent experimental work it has been observed that the position of the centre of pressure (CoP) at the brake pad/disc interface has an influence on the onset of brake squeal. To determine the CoP during a braking event, a simple two-dimensional analytical model of the brake pad or more complex numerical finite element model of a disc brake are commonly used. This paper presents a new three-dimensional analytical model of a brake pad that determines the CoP position in both circumferential and radial directions. Due to higher complexity, this model provides more realistic clamp and friction force values, which can be used together with the more accurate radial position of the CoP for evaluation of the brake torque. The CoP position calculated using the new model was compared with the CoP evaluated by a finite-element model of an equivalent 8-piston opposed disc brake. The CoP results across the whole pad/disc interface showed a close correlation between these two approaches, giving the new analytical model a potential use in applications where an instantaneous value of the CoP with good accuracy is required. Finally, the new model was used to demonstrate possible improvement of the traditional method of the friction coefficient calculation. Due to greater accuracy the new model gives an approximately 8% larger value of the friction coefficient than the traditional approach.

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Doldi, Philipp Maximilian, Lukas Stolz, Felix Escher, Julius Steffen, Jonas Gmeiner, Daniel Roden, Marie Linnemann et al. « Transcatheter Aortic Valve Replacement with the Self-Expandable Core Valve Evolut Prosthesis Using the Cusp-Overlap vs. Tricusp-View ». Journal of Clinical Medicine 11, n^o 6 (12 mars 2022) : 1561. http://dx.doi.org/10.3390/jcm11061561.

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Despite the rapid increase in experience and technological improvement, the incidence of conduction disturbances in patients undergoing transcatheter aortic valve replacement (TAVR) with the self-expandable CoreValve Evolut valve remains high. Recently, a cusp-overlap view (COP) implantation technique has been proposed for TAVR with self-expandable valves offering an improved visualization during valve expansion compared to the three-cusp view (TCV). This study aims to systematically analyze procedural outcomes of TAVR patients treated with the CoreValve Evolut valve using a COP compared to TCV in a high-volume center. The primary endpoint was technical success according the 2021 VARC-3 criteria. A total of 122 consecutive patients (61 pts. TCV: April 2019 to November 2020; 61 pts. COP: December 2020 to October 2021) that underwent TAVR with the CoreValve Evolut prosthesis were included in this analysis. Although there was no difference in the primary endpoint technical success between TCV and COP patients (93.4% vs. 90.2%, OR 0.65, 95% CI 0.16, 2.4, p = 0.51), we observed a significantly lower risk for permanent pacemaker implantation (PPI) among COP patients (TCV: 27.9% vs. COP: 13.1%, OR 0.39, 95% CI 0.15, 0.97, p = 0.047). Implantation of the CoreValve Evolut prosthesis using the COP might help to reduce the rate of PPI following TAVR.

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Lopes, Priscila Garcia, José Augusto Fernandes Lopes, Christina Moran Brito, Fábio Marcon Alfieri et Linamara Rizzo Battistella. « Relationships of Balance, Gait Performance, and Functional Outcome in Chronic Stroke Patients : A Comparison of Left and Right Lesions ». BioMed Research International 2015 (2015) : 1–8. http://dx.doi.org/10.1155/2015/716042.

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Introduction. This study compared the balance by center of pressure (COP) and its relationship with gait parameters and functional independence in left (LH) and right (RH) chronic stroke patients.Methods. In this cross-sectional study, twenty-one hemiparetic stroke patients were assessed for Functional Independence Measure (FIM), balance with a force platform, and gait in the Motion Analysis Laboratory.Results. The amplitudes of the COP in the anteroposterior and mediolateral directions were similar in both groups. The anteroposterior direction was greater than the mediolateral direction. Only the temporal parameters showed any statistically significant differences. The LH showed a significant correlation between stride length, step length, and gait velocity with COP velocity sway for the healthy and paretic lower limbs. In both groups, the area of COP was significantly correlated with stride length. Motor FIM was significantly correlated with the COP in the LH group.Conclusion. There was no difference in the performance of balance, gait, and functional independence between groups. The correlation of the COP sway area with stride length in both groups can serve as a guideline in the rehabilitation of these patients where training the static balance may reflect the improvement of the stride length.

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Jemni, Nourheine, Mouna Elakhdar, Ezzedine Nehdi et Lakdar Kairouani. « Performance Investigation of Cascade Refrigeration System Using CO2 and Mixtures ». International Journal of Air-Conditioning and Refrigeration 23, n^o 03 (septembre 2015) : 1550022. http://dx.doi.org/10.1142/s2010132515500224.

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This paper presents reports on simulation and comparative analysis of single stage vapor compression refrigeration system and cascade systems using carbon dioxide, hydrocarbons (HCs) and CO2/HCs mixture. Thermodynamic parameters of fluids are given using the software REFPROP 9.0. To select the most suitable HCs, three criteria have been fixed: Tc, Tt and Tb. It is found that the HCs chosen in low-stage are propane, propylene and ethane and those for the high-stage are propane, propylene and isobutane. The fraction mixture in the two loops has been varied and results are compared with single stage and cascade systems using CO2 and R22. The fraction x[Formula: see text] is varied in the two loops. Results are compared for single and cascade systems using CO2 and R22. For the single stage system, we find for xCO2 = 0.5, an improvement of COP of 14% for CO2/propane mixture and 36% for the CO2/propylene mixture. It is found that for xCO2 = 0.3, cascade system using propane/CO2 mixtures presents a COP lower than that of cascade system using pure CO2. About of 70% of unfriendly fluids like CFCs and HCFCs can be replaced with CO2, without affecting the performance of cascade refrigeration systems.

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Ramdharry, G. M., J. F. Marsden, B. L. Day et A. J. Thompson. « De-stabilizing and training effects of foot orthoses in multiple sclerosis ». Multiple Sclerosis Journal 12, n^o 2 (avril 2006) : 219–26. http://dx.doi.org/10.1191/135248506ms1266oa.

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This study evaluates the effects of dynamic foot orthoses (DFO) on walking and balance performance in people with multiple sclerosis (MS). Sixteen ambulant subjects with MS and ten age-matched healthy control subjects were studied on initial receipt of foot orthoses and after four weeks of daily wear. Walking speed, MS Walking Scale-12 (MSWS-12) and standing balance were assessed with and without orthoses at both these times. During standing, stance width and vision were varied, and performance was quantified using the velocity of the centre of pressure (COP), body sway velocity and the mean COP position relative to the shoe. People with MS walked slower (p<0.001) and showed increased sway when standing (p<0.001). At the first assessment, the foot orthoses caused an increase in sway and a medial and posterior shift of the COP position. At repeat measurement, the DFOs continued to increase sway compared to a shoe only condition. However, MS subjects reported an improvement in the MSWS-12 (p<0.05) and, compared to the initial session, showed decreased sway when eyes were closed both with and without DFOs. Dynamic foot orthoses may increase sway and change COP position by altering foot alignment and/or plantar afferent stimulation. Improvement in body sway over time may be an overall training effect of the DFOs, as MS subjects adapt to the initial de-stabilization.

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Hafis, Mohd Bin Sulaiman, Mohd Jamir Mohd Ridzuan, Ahamad Zaidi Ahmad Firdaus, S. M. Shahril, Ramli Nur Farahana et C. K. Chong. « COP Improvement of Thermoelectric Cooler through the Optimization of Heat Dissipation System ». Applied Mechanics and Materials 554 (juin 2014) : 241–45. http://dx.doi.org/10.4028/www.scientific.net/amm.554.241.

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This paper presents theoretical and experimental works on the effect of heat transfer for a thermoelectric (TE) cooling system. The study focuses on thermal performance of the system through the optimisation of heat dissipation system for two prototypes that have aluminium and copper heat sink design, respectively. The study revealed that heat sink base area and fin height influenced thermal performance.

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Ariful Kabir, K. M., Rifat A. Rouf, M. M. A. Sarker, K. C. Amanul Alam et Bidyut B. Saha. « Improvement of COP with Heat Recovery Scheme for Solar Adsorption Cooling System ». International Journal of Air-Conditioning and Refrigeration 26, n^o 02 (juin 2018) : 1850016. http://dx.doi.org/10.1142/s2010132518500165.

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Heat recovery ensures optimum usage of the collected energy, and thus, minimizes heat loss for a solar adsorption chiller. Two-bed adsorption chiller with conventional single stage, run by direct solar coupling with heat recovery, has been studied mathematically. In a heat recovery adsorption refrigeration system, to facilitate heat transfer, heat transfer fluid is distributed between two adsorbers maintaining the same mass flow rate. There is no mass transfer between system components during this phase. It is a semi-continuous system performed between two adsorption beds. After completion of desorption/condensation mode, heat transfer fluid is allowed to circulate between the heated desorber and the cooled adsorber. This process distributes some heat of the desorption bed to the adsorber preparing it for the next preheating mode where heat transfer between them is done adiabatically. Consequently, the performance has been checked and a satisfactory increase in the Coefficient of Performance (COP) (approximately 15%) has been detected in the calculated results for the heat recovery operation. It is also observed that the heat recovery process enhances the working hour and overall performances of the solar heat driven adsorption chiller.

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KIM, HYUN JIN, WOO YOUNG KIM, JONG MIN AHN et SUNG OUG CHO. « NUMERICAL STUDY ON THE PERFORMANCE IMPROVEMENT OF A ROTARY VANE EXPANDER FOR A CO2 HEAT PUMP CYCLE ». International Journal of Air-Conditioning and Refrigeration 19, n^o 04 (décembre 2011) : 311–19. http://dx.doi.org/10.1142/s2010132511000648.

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In order to recover friction loss in the expansion process and increase refrigeration effect in a CO2 heat pump cycle, a rotary vane expander has been designed. Numerical simulation has been carried out to estimate the performance of designed expander, and it has been found that vane jumping or vane recession from the cylinder wall occurs in a certain range of the crank angle. To improve the vane motion, a way of pressurizing the vane back chamber has been employed, and elimination of the vane jumping phenomenon has been confirmed by the numerical simulation. With the operating pressure conditions of 9 MPa/4.5 MPa and inlet temperature of 35°C, the expander efficiency has been calculated to be 42.72%, and improvement of COP of a CO2 heat pump cycle with this expander has been estimated to be about 12.82%.

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Tong, Yun, et Pengzuo Chen. « Cobalt phosphide nanowires with adjustable iridium, realizing excellent bifunctional activity for acidic water splitting ». Dalton Transactions 50, n^o 21 (2021) : 7364–71. http://dx.doi.org/10.1039/d1dt00839k.

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A dramatic improvement in the bifunctional performance of CoP material was realized utilizing a low amount of iridium as an effective dopant, presenting superior catalytic activity for overall water splitting in acidic medium.

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Li, Shengyu, et Jun Lu. « A Theoretical Comparative Study of Vapor-Compression Refrigeration Cycle using Al2O3 Nanoparticle with Low-GWP Refrigerants ». Entropy 24, n^o 12 (13 décembre 2022) : 1820. http://dx.doi.org/10.3390/e24121820.

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Nanorefrigerant is a mixture of nanoparticles and pure refrigerant, which can increase heat transfer characteristics in refrigeration and air conditioning equipment. The performance of four different Al2O3 nanorefrigerants and their pure fluids (R600a, R134a, R1234yf, and R1233zd(E)) is analyzed in a vapor-compression refrigeration cycle. The enthalpy of a nanorefrigerant in the refrigeration cycle is calculated by using the prediction method based on the density of nanorefrigerant. A numerical model is established for the thermodynamic analysis, and the results show that adding nanoparticles to the pure refrigerant enhances heat transfer in heat exchangers, increases cooling capacity, reduces compressor power consumption, and finally improves the performance of the refrigeration system. The COP improvement of R1233zd(E) + Al2O3 nanorefrigerant is the highest, and the COP improvement of R134a + Al2O3 and R1234yf + Al2O3 are close to each other. When the mass fraction of Al2O3 nanoparticles increases to 0.30%, the COP of R1233zd(E) and R600a increases by more than 20%; the maximum exergy efficiency is 38.46% for R1233zd(E) + Al2O3, and the minimum exergy efficiency is 27.06% for pure R1234yf. The results provide a basis for the application of nanorefrigerants in the vapor compression refrigeration cycle.

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Armoogum, K., et M. Buchgeister. « Factors affecting knowledge sharing in the radiotherapy department : the radiation physics team as a community of practice ». Journal of Radiotherapy in Practice 9, n^o 1 (25 février 2010) : 17–26. http://dx.doi.org/10.1017/s1460396909990215.

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AbstractWe put forward the concept of the radiotherapy physics team as a community of practice (COP). Radiotherapy physicists are required to continuously develop their scientific, computational and management competencies. Much of this knowledge is gained through peer-to-peer interaction in a structured environment, enabling the individual to increase their tacit knowledge. Such interaction among peers will allow issues to be framed within their context, information to be shared, decisions to be made and protocols to be developed. The structure that allows physicists to create, share and manage knowledge conforms to the accepted definition of a COP. By implementing the methods of literature review and peer group survey, we have investigated the applicability of the concept of a radiotherapy physics COP. The results of the survey have shown a generally positive medical physicist training outlook in the UK and Germany, but highlighted certain areas where improvement is needed. Our surveys have shown that while most trainees are adequately supported, there are two areas where improvements can easily be made. Spatial factors, such as departmental geography, may not always be conducive to knowledge sharing but can readily be altered in most cases. The paucity of departmental seminars and journal club meetings has been highlighted as a problem at some training centres.

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Shin, Ji-Hyun, Yong-In Kim et Young-Hum Cho. « Development of Operating Method of Multi-Geothermal Heat Pump Systems Using Variable Water Flow Rate Control and a COP Prediction Model Based on ANN ». Energies 12, n^o 20 (15 octobre 2019) : 3894. http://dx.doi.org/10.3390/en12203894.

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As the global energy trend continues, the importance of energy savings and efficient use is being emphasized, and the installation and operation of geothermal heat pump systems is increasing. In many buildings, where an actual geothermal heat pump system has been installed, problems of efficiency deterioration occur frequently because of the inefficient operation after installation of the heat pump system. The purpose of this study was to develop and verify the operating method for energy saving and performance improvement of multiple geothermal systems. A coefficient of performance (COP) prediction model using an artificial neural network for real-time COP predictions was developed. The operating method of a multi-geothermal heat pump system using a variable water flow rate control method and COP prediction model was developed. The geothermal heat pump system operates sequentially depending on the water flow rate of the circulation pump. The COP prediction model enabled real-time performance prediction during system operation. The circulation water flow rate was reduced by up to 29% compared to the existing operating method. Approximately 23% of the energy was saved. The COP system, including the consumption power of the circulation pump, was improved.

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Erdman, Ashley L., Sophia Ulman, Alex Loewen, Hannah Worrall, Kirsten Tulchin-Francis, Jacob C. Jones, Jane S. Chung, Henry B. Ellis, C. Munro Cullum et Shane M. Miller. « Improvement in Postural Control Following Concussion in Adolescent Athletes : From Clinical Presentation to Initiation of Return to Play ». Orthopaedic Journal of Sports Medicine 10, n^o 5_suppl2 (1 mai 2022) : 2325967121S0040. http://dx.doi.org/10.1177/2325967121s00400.

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Background: Impairments in balance or postural control are common following sport-related concussion (SRC). The Balance Error Scoring System (BESS) is widely utilized to assess static postural stability, but laboratory-based balance measures have been shown to more accurately detect changes in postural control. Hypothesis/Purpose: To determine whether postural control improved between presentation to the sports medicine clinic and return-to-sport (RTS) initiation, and whether this trend mirrored symptom scores and cognitive performance. A secondary aim was to assess whether changes in postural control were more accurately captured with center of pressure (COP) based measures compared to BESS. Methods: Patients diagnosed with a SRC were tested within 10 days of presentation (V0) and when cleared by a physician to begin a RTS protocol (V1). Clinical measures included Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and the King-Devick (K-D) test. The BESS was performed with eyes closed while standing barefoot on a force platform for 6 conditions: double-limb stance, single-limb stance, and tandem stance on both firm and foam surfaces. BESS scores and total balance time were recorded for each condition, and COP-based measures were computed for both double-limb stance conditions (Table 1). Sample entropy was computed to quantify COP regularity over time with increased values indicating improvement in postural control. Wilcoxon signed-rank tests were performed to determine significance between visits ( α<0.05). Results: Forty patients (17 males, 13.8±2.0 years) were included for analysis. ImPACT verbal and visual memory scores improved by 10% and 12%, respectively, total symptom score decreased (V0 18.03±13.85, V1 0.97±2.08; p<0.01), and visual motor speed and reaction time were both 11% faster on the K-D test. For postural control, the BESS indicated significant improvement given the reduction in errors on both surfaces (Firm Total: V0 3.23±2.09, V1 2.25±2.11, p=0.01; Foam Total: V0 7.38±2.05, V1 6.08±1.76, p<0.01; Table 1). Similarly, COP-based measures exhibited better overall balance between visits (Figure 1), primarily in the medial-lateral direction on the firm and the anterior-posterior direction on the foam. Lastly, sample entropy improved between visits, indicating more effective postural control. Conclusion: Significant improvement in postural control was observed during the recovery period which mirrored improvement in symptom scores and cognitive performance. Additionally, while COP-based measures showed similar trends to the BESS, they provided more detailed information in regards to balance recovery. Specifically, findings from the double stance condition highlight the utility of a more advanced assessment of postural control for determining RTS readiness following a SRC. [Table: see text][Figure: see text]

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Sedighi, K., M. Farhadi et M. Liaghi. « Exergy analysis : Parametric study on lithium bromide—water absorption refrigeration systems ». Proceedings of the Institution of Mechanical Engineers, Part C : Journal of Mechanical Engineering Science 221, n^o 11 (1 novembre 2007) : 1345–51. http://dx.doi.org/10.1243/09544062jmes604.

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In the current study, an exergy analysis of a single-effect absorption refrigeration cycle using lithium bromide-water solution is carried out. The cycle has been analysed by considering the mass and energy conservation based on the first and second laws of thermodynamics. This analysis provides a detailed information on the effect of different parameters on the system performance. The coefficient of performance (COP), exergetic efficiency (ECOP), and exergy destruction are determined. The results show that a reduction in cooling water temperature caused an improvement in the COP and ECOP. Increasing the evaporator temperature has also improved the COP, but it caused a reduction in the ECOP of the system. Also it can be seen that the parameters' variation at the solution side has a more significant effect on cycle performances.

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Sumeru, Kasni, Triaji Pangripto Pramudantoro et Andriyanto Setyawan. « Experimental investigation on the performance of residential air conditioning system using water condensate for subcooling ». MATEC Web of Conferences 197 (2018) : 08002. http://dx.doi.org/10.1051/matecconf/201819708002.

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The experimental investigation of subcooling effects on system COP was carried out on a residential air conditioning using R410A as working fluid, with a compressor capacity of about 0.75 kW. In the experiment, the indoor and outdoor temperatures were controlled at 24°C and 32°C. The results showed that the use of condensate water lowers the refrigerant temperature in the condenser outlet by 2.7°C. By lowering the refrigerant temperature, the cooling capacity of the air conditioning can be enhanced. The decrease in of refrigerant temperature results in COP improvement 16.4%. Besides increasing the COP, the condensate water also decreases the discharge compressor temperature by 7.6°C. The decrease in of the discharge compressor temperature resulted in the decrease in power consumption of the air conditioning system by 5.9%.

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Sumeru, Kasni, Henry Nasution et Farid Nasir Ani. « Numerical Analysis of Modified Ejector Cycle on Ejector as an Expansion Device on Residential Air Conditioner ». Applied Mechanics and Materials 554 (juin 2014) : 261–65. http://dx.doi.org/10.4028/www.scientific.net/amm.554.261.

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The present study describes thermodynamic modeling of a novel cycle of ejector as an expansion device - called modified ejector cycle (MEC) - on residential air conditioner (A/C) to further enhance the COP improvement on standard ejector cycle (SEC). The difference between the SEC and MEC is the separator, namely the SEC uses a separator that has an inlet and two outlets, whereas in modified ejector cycle (MEC), the separator has only an inlet and an outlet in the system. Due to its environmental friendliness of R290 (propane), it is used to replace R22 as a working fluid in the numerical. The modeling results on the residential air conditioner with cooling capacity of 2.5 kW using R290 as working fluid showed that the COP improvement of the MEC was 42.86% at the condenser temperature of 45°C.

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Moreno-Muñoz, María del Mar, Fidel Hita-Contreras, María Dolores Estudillo-Martínez, Agustín Aibar-Almazán, Yolanda Castellote-Caballero, Marco Bergamin, Stefano Gobbo et David Cruz-Díaz. « The Effects of Abdominal Hypopressive Training on Postural Control and Deep Trunk Muscle Activation : A Randomized Controlled Trial ». International Journal of Environmental Research and Public Health 18, n^o 5 (8 mars 2021) : 2741. http://dx.doi.org/10.3390/ijerph18052741.

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Background: Abdominal Hypopressive Training (AHT) provides postural improvement, and enhances deep trunk muscle activation. However, until recently, there was a lack of scientific literature supporting these statements. The major purpose of this study was to investigate the effect of AHT on posture control and deep trunk muscle function. Methods: 125 female participants aged 18–60 were randomly allocated to the Experimental Group (EG), consisting of two sessions of 30 min per week for 8 weeks of AHT, or the Control Group (CG), who did not receive any treatment. Postural control was measured with a stabilometric platform to assess the static balance and the activation of deep trunk muscles (specifically the Transverse Abdominal muscle (TrA)), which was measured by real-time ultrasound imaging. Results: The groups were homogeneous at baseline. Statistical differences were identified between both groups after intervention in the Surface of the Center of Pressure (CoP) Open-Eyes (S-OE) (p = 0.001, Cohen’s d = 0.60) and the Velocity of CoP under both conditions; Open-Eyes (V-OE) (p = 0.001, Cohen´s d = 0.63) and Close-Eyes (V-CE) (p = 0.016, Cohen´s d = 0.016), with the EG achieving substantial improvements. Likewise, there were statistically significant differences between measurements over time for the EG on S-OE (p < 0.001, Cohen´s d = 0.99); V-OE (p = 0.038, Cohen´s d = 0.27); V-CE (p = 0.006, Cohen´s d = 0.39), anteroposterior movements of CoP with Open-Eyes (RMSY-OE) (p = 0.038, Cohen´s d = 0.60) and activity of TrA under contraction conditions (p < 0.001, Cohen´s d = 0.53). Conclusions: The application of eight weeks of AHT leads to positive outcomes in posture control, as well as an improvement in the deep trunk muscle contraction in the female population.

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Karthick, Munuswamy, Senthil Karuppiah et Varatharajan Kanthan. « Performance investigation and exergy analysis of vapor compression refrigeration system operated using R600a refrigerant and nanoadditive compressor oil ». Thermal Science 24, n^o 5 Part A (2020) : 2977–89. http://dx.doi.org/10.2298/tsci180527024m.

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Compression of vaporized refrigerant is the essential process of the refrigeration cycle which is performed by using a compressor. The amount of power consumed by a refrigeration system is governed by the work input given to its compressor, which also determines the COP of the system. By reducing the work input given to the compressor, the power consumption of refrigerator is reduced along with the improvement in its COP. Nowadays, nanoparticles have emerged as the new generation additives in various working fluids because of their remarkable ability to improve the heat transfer, tribological and other thermophysical properties of the base fluid. In such a vein, we propose a compressor oil based nanofluid prepared by dispersing nanoparticles into the conventional compressor oil. In the present study, four samples of nanoadditive compressor oil were prepared by dispersing the nanoparticles like Al2O3, TiO2, and ZnO into the conventional mineral oil as a lubricant. The tribological properties of this four samples were studied, out of which one sample gave a better lubrication and heat transfer properties which are considered as one of the key parameters for reducing work input to the compressor, this can result in reduced power consumption, with enhancement of COP. These results are analyzed experimentally by carrying out performance and exergy analysis in a vapor compression refrigeration system, using R600a as a refrigerant. The experimental results show that, there is an improvement of COP by 14.61% and exergy efficiency by 7.51%. Also, the efficiency defect in the major components of vapor compression refrigeration system has been reduced effectively.

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Vallabhajosula, Srikant, Beverly L. Roberts et Chris J. Hass. « Tai Chi Intervention Improves Dynamic Postural Control During Gait Initiation in Older Adults : A Pilot Study ». Journal of Applied Biomechanics 30, n^o 6 (décembre 2014) : 697–706. http://dx.doi.org/10.1123/jab.2013-0256.

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Tai Chi intervention has been shown to be beneficial for balance improvement. The current study examined the effectiveness of Tai Chi to improve the dynamic postural control among older adults with mobility disability. Six sedentary older adults with mobility disability participated in a 16-week Tai Chi intervention consisting of one hour sessions three times a week. Dynamic postural control was assessed pre- and post intervention as participants initiated gait in four stepping conditions: forward; 45° medially, with the stepping leg crossing over the other leg; 45° and 90° laterally. The center of pressure (CoP) displacement, velocity, and its maximum separation distance from the center of mass in the anteroposterior, mediolateral, and resultant directions were analyzed. Results showed that in the postural phase, Tai Chi increased the CoP mediolateral excursions in the medial (13%) and forward (28%) conditions, and resultant CoP center of mass distance in the medial (9%) and forward (19%) conditions. In the locomotion phase, the CoP mediolateral displacement and velocity significantly increased after the Tai Chi intervention (both by > 100% in the two lateral conditions). These results suggest that through alteration in CoP movement characteristics, Tai Chi intervention might improve the dynamic postural control during gait initiation among older adults.

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Ciaian, Pavel, Kamel Louhichi et Angel Perni. « Farm Level Impacts of Trade Liberalisation and CAP Removal Across EU : An Assessment using the IFM-CAP Model ». German Journal of Agricultural Economics 69, n^o 2 (29 mai 2020) : 108–26. http://dx.doi.org/10.30430/69.2020.2.108-126.

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This paper assesses the farm-level impacts of trade liberalisation and CAP removal across EU using IFM-CAP (Individual Farm Model for CAP Analysis). IFM-CAP is a static positive programming model developed to capture the full heterogeneity of EU farms in terms of feedback to policy representation and impacts. Simulation results show that a small set of farm-types experience an increase in income due to the improvement in prices and yields (e.g. farms specialised in granivores, milk and horticulture), while farms that are most CAP subsidy dependent (e.g. specialist cattle, specialist COP and small farms) lose income by more than 12% at aggregate EU level. As much as 77% of all farms lose income if CAP is removed, while the proportion of most income vulnerable farms almost doubles.

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Arsana, Made Ery, I. Gusti Bagus Wijaya Kusuma, Made Sucipta et I. Nyoman Suamir. « Exergy and Energy Analyses of Dual-Temperature Evaporator Split AC System Incorporated A Capillary Tube and A Two-Phase Ejector ». Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 77, n^o 1 (7 novembre 2020) : 88–99. http://dx.doi.org/10.37934/arfmts.77.1.8899.

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This study was aimed to investigate performance of a split type air conditioning (SAC) system applying exergy destruction method. A numerical model was established based on exergy destruction analysis of a Condenser Outlet Split-Split Air Conditioning (COS-SAC) system integrated with dual-temperature evaporator and incorporated capillary tube and ejector as expansion devices. An experimental test system was also established to experimentally validate the model. Two type of refrigerants R-290 and R-22 were involved in the evaluations. The Coefficient of Performance (COP) of the ejector COS-SAC system, exergy destruction, and exergy efficiency were determined and compared with those in the SAC system utilizing capillary tube. The results showed there was a significant improvement in the overall exergy efficiency of the COS-SAC systems. The COP of the COS-SAC system was also found to be better than the COP of the SAC system.

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Davies, Deborah J. « Quality improvement initiatives in a case management service : case study ». Australian Journal of Primary Health 21, n^o 1 (2015) : 14. http://dx.doi.org/10.1071/py13111.

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This article explores the importance of quality practices in underpinning the person-centred approach at a Community Options Program (COP) case management service in northern NSW. The NSW community care sector does not have a statutory excellence body to identify, promote and support improved practices and quality and safety across community services, and therefore the COP provider decided to establish a dedicated role to focus on the quality improvement of its service. The subsequent quality improvement initiatives have included mapping the clients’ journey through the service, identifying areas to standardise practice, and creating service pathways. The clients’ journey was used as the framework to identify where standardised practice was required, and a robust process was implemented to develop over 25 good practice guidelines and tools that addressed the variations in practice and enabled the service pathways to be developed. Prior to trialling the guidelines and tools, staff received education sessions on the anticipated changes to practice, and the practicality and applicability of the guidelines were evaluated at the end of the trials. This information was reviewed and the guidelines were amended accordingly before being rolled out. The guidelines have been in use for over 12 months and have provided the benchmark against which to audit practice, and have resulted in key performance improvements such as an increase in client review rates and a rise in the feedback response rate from clients, with a noticeable shift in the comments about the brokered support worker to acknowledging the role of their case manager. Formalising informal supports for those clients that lived alone also increased, which means these people are less reliant on services and there is a reduced risk of social isolation.

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