Articoli di riviste: "Flooded evaporator"

1

Hung, Kuo-Shu, Jenn-Chyi Chung, Chung-Che Liu, Jun-Jie Lin e Chi-Chuan Wang. "A Comparative Study of the Oil-Free Centrifugal Water Chillers with the Flooded or Falling Film Evaporator—A Case Study". Energies 12, n. 13 (2 luglio 2019): 2548. http://dx.doi.org/10.3390/en12132548.

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A comparative study regarding the performance of real-scale oil-free centrifugal chillers having the flooded evaporator or falling film evaporator was conducted in this study. The nominal capacity for the test chillers was around 200~230 USRT (US refrigeration ton) (703~809 kW). The compressors of the two chillers were identical and R-134a was used as the working fluid. Both evaporators employed the same enhanced tubes (GEWA-B) to fulfill phase change. Tests were conducted in full, 75%, 50%, and 25% loading. Test results indicate that both chillers contained a comparable system performance with an integrated part-load value of around 8.62~8.63. The overall heat transfer coefficient for the flooded evaporator was appreciably higher (20~40%) than the falling film evaporator. This is because the falling film flowrate was below the threshold value and the heat transfer was dominated by evaporation mode. Yet, the heat transfer performance for the falling film evaporator was further jeopardized due to starvation of the film flowrate (partial dry-out), especially in the middle or bottom of the tube bundle. This phenomenon became even more pronounced at partial loading (25%), whereas the flooded evaporator did not reveal such a performance dip at partial loading.

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Yoon, Jung-In, Chang-Hyo Son, Hyung-Min Han, Kwang-Seok Lee, Jung-Mok Lee e In-Duck You. "Heat Transfer Characteristics of Flooded Type Evaporator for Seawater Cooling System". MATEC Web of Conferences 167 (2018): 02014. http://dx.doi.org/10.1051/matecconf/201816702014.

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In these days, many studies on ocean fisheries have been conducted for developing their own industries. Especially, the efforts of using seawater cooling system were actively conducted to keep the caught fisheries fresh, increase the catches, and decrease the manpower. The purpose of this study is to suggest design criteria of seawater cooling system using the flood-type evaporator. In this study, the seawater cooling system using flooded-type evaporator was manufactured as a prototype capacitating 15kW. This study examined performance of the seawater cooling system and then compared the performance with the system capacitating 163kW and 238kW, which is actually being loaded on the fishery boats. In addition, heat transfer characteristics of the flooded-type evaporator used in the equipment are analysed.

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Zhou, Ji Cheng, Dong Sheng Zhu, Zheng Qi Huo, Jun Li e Yan Li. "Pool Boiling Heat Transfer Characteristics on Twisted Tube Bundles in a Flooded Evaporator". Applied Mechanics and Materials 416-417 (settembre 2013): 1049–55. http://dx.doi.org/10.4028/www.scientific.net/amm.416-417.1049.

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The objectives of this paper are to study the pool boiling heat transfer characteristics of twisted tubes in the flooded evaporator. The twisted tubes are processed from common circular evaporating tubes with an outer diameter of 15.88mm. The outer major axis diameter, minor axis diameter, wall thickness and length of the twisted tube are 19.50mm, 11.28mm, 1.09mm, and 3310mm, respectively. The outside tube pool boiling heat transfer coefficients, tube side Reynolds numbers, the wall superheat, the saturation temperature of refrigerant and the heat flux are considered as the key parameters. The results show that pool boiling heat transfer coefficient data increase with , and , respectively, and decrease as the wall superheat increases. It can be found in the case study that the overall heat transfer coefficient of twisted tube flooded evaporator (TFE) is about 1.15 times as high as the one of common flooded evaporator (FE) with a same heat capacity. It is proved that an application of the TFE in the water-cooled screw chiller can be feasible.

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Huang, Xinghua, Yunqian Zhang, Zuqiang Li e Yaolin Lin. "Measurement Method and Experimental Analysis of Liquid Entrainment for a Flooded Evaporator of a Water-Cooled Centrifugal Chiller Based on Energy Balance". Applied Sciences 11, n. 17 (2 settembre 2021): 8165. http://dx.doi.org/10.3390/app11178165.

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Liquid entrainment in a flooded evaporator has an important impact on the performance and safety of a water-cooled centrifugal chiller. In this paper, two methods for measuring the liquid entrainment factor in the evaporator of a centrifugal chiller based on energy balance are proposed. Method 1 involves only the heat exchange capacity of the evaporator and Method 2 involves both evaporator and condenser. The applicable conditions of the methods are discussed. Experimental measurements on the flooded evaporator of a single-stage water-cooled centrifugal chiller with refrigerant R134a show that, for a system with good thermal balance, there is little difference in the entrainment factor values obtained by the two methods. Method 2 was found to have slightly higher measurement accuracy, compared to Method 1. The uncertainty propagation analysis shows that for Method 2, the inlet and outlet water temperatures of the evaporator and condenser, motor input power, motor efficiency, transmission power loss and compressor suction and discharge temperatures are important factors. The experimental results show that the variation of the evaporator entrainment factor with refrigerant charge amount is different for different cooling capacity. At 700 and 800 refrigeration ton (RT), the entrainment factor of the test evaporator increases with the increase of refrigerant charge and the growth rate gradually accelerates. For the chiller tested, when the entrainment factor reaches 0.89% and 1.02%, respectively, at 700 ton and 800 ton, the rapid increase of the entrainment factor leads to a significant decrease in the coefficient of performance (COP) during the charging process. Based on the analysis of the experimental results, it is recommended that the maximum entrainment factor for efficient operation of the centrifugal chiller should be controlled within 1%.

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Yoon, Jung-In, Chang-Hyo Son, Choon-Geun Moon, Joon-Hyuk Lee, Kwang-Seok Lee, Suk-Ho Jung e Doo-Yeong Kwak. "Economic Evaluation of Seawater Cooling System Applying Flooded Type Evaporator". IOP Conference Series: Materials Science and Engineering 520 (17 aprile 2019): 012006. http://dx.doi.org/10.1088/1757-899x/520/1/012006.

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Thimmaiah, Poovanna Cheppudira, Amir Sharafian, Mina Rouhani, Wendell Huttema e Majid Bahrami. "Evaluation of low-pressure flooded evaporator performance for adsorption chillers". Energy 122 (marzo 2017): 144–58. http://dx.doi.org/10.1016/j.energy.2017.01.085.

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7

Ayub, Zahid H., M. C. Chyu e Adnan H. Ayub. "Different Types of Carbon Steel Enhanced Tubes in Ammonia Flooded Evaporator". Heat Transfer Engineering 27, n. 5 (giugno 2006): 39–44. http://dx.doi.org/10.1080/01457630600559587.

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8

Haitao, Hu, Lai Zhancheng, Zhan Feilong, Chen Song, Ding Guoliang e Zhuang Dawei. "Optimization of tube bundle arrangement for flooded shell-and-tube evaporator". Energy Procedia 142 (dicembre 2017): 3799–804. http://dx.doi.org/10.1016/j.egypro.2017.12.279.

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Ayub, Zahid H. "Case Study: Practical Application of Enhancement Device in an Ammonia Flooded Evaporator". Journal of Enhanced Heat Transfer 6, n. 1 (1999): 31–35. http://dx.doi.org/10.1615/jenhheattransf.v6.i1.30.

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10

Okereke, Chukwuemeka J., Idehai O. Ohijeagbon e Olumuyiwa A. Lasode. "Energy and Exergy Analysis of Vapor Compression Refrigeration System with Flooded Evaporator". International Journal of Air-Conditioning and Refrigeration 27, n. 04 (dicembre 2019): 1950041. http://dx.doi.org/10.1142/s201013251950041x.

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In this study, energy and exergy analysis was used to evaluate the performance of a vapor compression refrigeration system with a flooded evaporator and the causes of high temperatures of beverage during the production process determined. Subsequently, the components of the operation that require modification were identified in order to improve the system performance. The actual operating parameters related to energy and exergy analysis of the investigated beverage manufacturing plant were measured, the thermal properties of the beverage were determined from a calorimeter experiment, and mathematical models were developed based on the first and second laws of thermodynamics from the literature. The system energy and exergy efficiencies were 57.46% and 21.17%, respectively, whereas the system exergy destruction was 695.71[Formula: see text]kW. The highest exergy destruction among the components of the refrigeration system occurred at the cooling plate, followed by the ammonia compressor. The cooling plate also experienced a loss in the refrigerating effect of 43.59[Formula: see text]kW. Therefore, the cooling plate is the area with the highest potential for improvement. The ammonia compressor presents another potential area of improvement, which includes operating the compressor at a high compression ratio and high superheated temperature. However, the reduction of beverage inlet mass flow rate at the cooling plate offers the best opportunity to achieve a low beverage temperature between 1.00∘C and 2.00∘C and decreasing the system exergy destruction without incurring additional investment costs.

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11

Le, C. V., P. K. Bansal e J. D. Tedford. "Simulation model of a screw liquid chiller for process industries using local heat transfer integration approach". Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 219, n. 2 (1 maggio 2005): 95–107. http://dx.doi.org/10.1243/095440805x7035.

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This paper presents a system simulation model of an oil-injected screw liquid chiller, where the refrigerant shell and tube heat exchangers are modelled following local heat transfer integration approach. All major components of the system are modelled in a modular format such as an oil-injected screw compressor, a shell and tube condenser, a flooded evaporator, and a high side-float valve. The simulation results are validated with the experimental data of a multiple-chiller plant at a process industry. The validated results show that the part-load ratio and the glycol-water temperature at the evaporator inlet affect the system performance considerably as compared to the temperature of cooling water entering the condenser.

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12

Asher, William, e Steven J. Eckels. "Characterization of liquid refrigerant R-123 flow emerging from a flooded evaporator tube bundle". Science and Technology for the Built Environment 24, n. 9 (8 maggio 2018): 1026–38. http://dx.doi.org/10.1080/23744731.2018.1464349.

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13

Jamil, Kaiser, K. N. Jyothi e A. L. Prasuna. "Electron Microscopic studies on the antennal sensilla and the pheromone-producing glands of two important oil seed pests". Proceedings, annual meeting, Electron Microscopy Society of America 48, n. 3 (12 agosto 1990): 570–71. http://dx.doi.org/10.1017/s0424820100160406.

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Sensory mechanisms underlying insect chemical communication have been given considerable attention in recent years. A study on the ultrastructural details of the antennal appendages and the pheromone producing structures of Achoea janata L. and Ophiusa algira were studied with scanning electron microscope in order to understand the mechanisms of olfactory perception and pheromone release.For fixation of pheromone producing glands of A.Janata and O.Algira the posterior region of the abdomen was pressed sufficiently and flooded with carnoys fluid for complete excedation of the 9th abdominal along with the ovipositor. The above specimens as well as the antennal appendages were then fixed in 4% glutaraldehyde in phosphate buffer of 7.2 pH dehydrated in increasing grades of ethylalcohol and critical point dried. The specimens were then coated with gold in vacuum evaporator and observed in a Hitachi S-520 evaporator and observed in a Hitachi S-520 SEM operated at 20KV.

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14

Krzywanski, Jaroslaw. "A General Approach in Optimization of Heat Exchangers by Bio-Inspired Artificial Intelligence Methods". Energies 12, n. 23 (22 novembre 2019): 4441. http://dx.doi.org/10.3390/en12234441.

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The paper introduces the artificial intelligence (AI) approach as a general method for the design and optimization study of heat exchangers. Genetic Algorithms (GA) and Artificial Neural Networks (ANN) are applied in the paper. An AGENN model, combining Genetic Algorithms with Artificial Neural Networks, was developed and validated against the desired data on a large falling film evaporator. A broad range of operating conditions and geometric configurations are considered in the study. Four kinds of tubes are deliberated, including plain and enhanced tubes. Different tube pass arrangements, i.e., top-to-bottom, bottom-to-top, and side-by-side, are discussed. Finally, the effects of liquid refrigerant mass flow rate, as well as the number of flooded tubes on the performance of the evaporator, are analyzed. The total heat transfer rate of the evaporator, predicted by the model, is in good agreement with the desired data; the maximum error is lower than ±3%. The highest heat transfer rate of the evaporator is 1140.01 kW and corresponds to Turbo EHP tubes, and bottom-to-top tubes pass arrangements, which guarantee the best thermal energy conversion. The presented approach can be referred to as a complementary technique in heat exchanger design procedures, besides the common rating and sizing tasks. It is an effective and alternative method for the existing approaches, considering the complexity of analytical and numerical techniques as well as the high costs of experiments.

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15

Haida, Michal, Jacek Smolka, Michal Palacz, Jakub Bodys, Andrzej Nowak, Zbigniew Bulinski, Adam Fic, Krzysztof Banasiak e Armin Hafner. "Numerical investigation of an R744 liquid ejector for supermarket refrigeration systems". Thermal Science 20, n. 4 (2016): 1259–69. http://dx.doi.org/10.2298/tsci151210112h.

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This paper presents a numerical investigation of an R744 liquid ejector applied to a supermarket refrigeration system. The use of the liquid ejector enables the operation of the evaporator in a flooded mode and recirculates the R744 liquid phase, which improves the energy efficiency of the refrigeration system. The investigation was performed using two ejectors of different sizes installed in a multi-ejector block. The numerical model was formulated based on the homogenous equilibrium model and validated with the experimental results. The influence of the pre-mixer, mixer and diffuser dimensions on the ejector performance measured using the mass entrainment ratio is presented. The results show that the best liquid ejector performance was obtained for the short lengths of the pre-mixer and mixer compared to the broadly investigated two-phase ejectors connected to the evaporator port. In addition, wide diffuser angles improved the mass entrainment ratio of both liquid ejectors, which may lead to a reduction in the diffuser length.

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16

Daraghmeh, Hafiz, Mohammed Sulaiman, Kai-Shing Yang e Chi-Chuan Wang. "Investigation of Separated Two-Phase Thermosiphon Loop for Relieving the Air-Conditioning Loading in Datacenter". Energies 12, n. 1 (29 dicembre 2018): 105. http://dx.doi.org/10.3390/en12010105.

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This study investigates the feasibility of using R-134a filled separated two-phase thermosiphon loop (STPTL) as a free cooling technique in datacenters. Two data center racks one of them is attached with fin and tube thermosiphon were cooled by CRAC unit (computer room air conditioning unit) individually. Thermosiphon can help to partially eliminate the compressor loading of the CRAC; thus, energy saving potential of thermosiphon loop was investigated. The condenser is a water-cooled design and perfluoroalkoxy pipes were used as adiabatic riser/downcomer for easier installation and mobile capability. Tests were conducted with filling ratio ranging from 0 to 90%. The test results indicate that the energy saving increases with the rise of filling ratio and an optimum energy savings of 38.7% can be achieved at filling ratios of 70%, a further increase of filling ratio leads to a reduction in energy saving. At a low filling ratio like 10%, the evaporator starves for refrigerant and a very uneven air temperature distribution occurring at the exit of data rack. The uneven temperature distribution is relieved considerably when the evaporator is fully flooded. It is also found that the energy saving is in line with the rise of system pressure. Overfilling of the evaporator may lead to a decline of system pressure. A lower thermal resistance occurs at high filling ratios and higher ambient temperature.

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Букин, Владимир Григорьевич, Vladimir Grigorievich Bukin, Александр Букин e Aleksandr Bukin. "Studying heat transfer in freon-oil mixture boiling in evaporator tubes in ship refrigerating units". Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2019, n. 4 (15 novembre 2019): 82–88. http://dx.doi.org/10.24143/2073-1574-2019-4-82-88.

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The paper describes small-capacity irrigation evaporators that improve the performance of a refrigeration unit, as they exclude the release of liquid freon into the compressor suction pipe under sharp increasing of heat load or during ship rolling. The relevance of studying heat transfer at freons boiling in a moving film has been proved. The results and analysis of experimental data on average heat transfer coefficients are presented. The graph shows the dependence of the average heat transfer coefficients on the heat flux density at various irrigation densities. There are presented the results of special experiments determining the effect of irrigation density on heat transfer. It has been stated that the effect of pressure or saturation temperature in the modes of evaporation and developed boiling manifests itself in different ways. With developed boiling, the beam pitch does not have a significant effect on heat transfer. The experiments were carried out on two stands: small-row and multi-row. The pipes were heated with an internal electric heater. It has been inferred that heat transfer in the film is more intense than in volume, therefore, smooth steel pipes can be used in irrigation evaporators instead of finned copper tubes, which are used in flooded devices. The boiling process in a film can be described by equations valid for a large volume, taking into account quantitative differences. The values of a constant coefficient and the criteria exponents are given; the similarity equation for the regime of developed bubble boiling of freons is derived. The calculated dependencies can be applied in evaluating the operation of irrigation evaporators of ship refrigeration units.

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18

Yoon, Jung-In, Chang-Hyo Son, Jeong-Mok Lee e In-Ho Kang. "Performance Characteristics of Flooded Type Evaporator for Seawater Cooling System with Heat Source Temperature of Mid-year". Journal of the Korea Society For Power System Engineering 21, n. 2 (30 aprile 2017): 64–69. http://dx.doi.org/10.9726/kspse.2017.21.2.064.

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19

Asher, William E., e Steven J. Eckels. "Characterization and numerical simulation of liquid refrigerant R-134a flow emerging from a flooded evaporator tube bundle". International Journal of Refrigeration 107 (novembre 2019): 275–87. http://dx.doi.org/10.1016/j.ijrefrig.2019.07.001.

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20

Zheng, J. X., G. P. Jin, M. C. Chyu e Z. H. Ayub. "Boiling of ammonia/lubricant mixture on a horizontal tube in a flooded evaporator with inlet vapor quality". Experimental Thermal and Fluid Science 30, n. 3 (gennaio 2006): 223–31. http://dx.doi.org/10.1016/j.expthermflusci.2005.06.001.

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21

Zheng, J., M. C. Chyu e Z. Ayub. "Boiling of ammonia/lubricant mixture on a horizontal enhanced tube in a flooded evaporator with inlet vapor quality". International Journal of Refrigeration 31, n. 4 (giugno 2008): 564–72. http://dx.doi.org/10.1016/j.ijrefrig.2007.06.016.

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22

Koo, Kyoung-Min, Soowon Lee, Sung-Gyu Kim, Young-Man Jeong, Jae-Keun Lee, Nae-Hyun Park, Byung-Chul Na et al. "Heat transfer property of refrigerant-oil mixture in a flooded evaporator: The role of bubble formation and oil retention". Korean Journal of Chemical Engineering 30, n. 5 (1 aprile 2013): 1029–33. http://dx.doi.org/10.1007/s11814-013-0024-9.

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23

Memory, S. B., S. V. Chilman e P. J. Marto. "Nucleate Pool Boiling of a TURBO-B Bundle in R-113". Journal of Heat Transfer 116, n. 3 (1 agosto 1994): 670–78. http://dx.doi.org/10.1115/1.2910921.

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Heat transfer measurements were made during nucleate boiling of R-113 from a bundle of 15 electrically heated, copper TURBO-B tubes arranged in an equilateral triangular pitch, designed to simulate a portion of a flooded evaporator. Five of the tubes that were oriented in a vertical array on the centerline of the bundle were each instrumented with six wall thermocouples. For increasing heat flux, the incipient boiling wall superheat of upper tubes decreased as lower tubes were activated. In the boiling region at low heat fluxes (≈ 1 kW/m2), the average bundle heat transfer coefficient was 4.6 times that obtained for a smooth tube bundle (under identical conditions) and 1.6 times greater than that obtained for a single TURBO-B tube; a similar bundle factor has been reported for a smooth tube bundle. At high heat fluxes (100 kW/m2), the average bundle heat transfer coefficient was 3.6 times that of a smooth tube bundle. Furthermore, there was still a significant bundle factor (1.22), contrary to a smooth tube bundle, where all effect of lower tubes was eliminated at high heat fluxes.

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Marto, P. J., e C. L. Anderson. "Nucleate Boiling Characteristics of R-113 in a Small Tube Bundle". Journal of Heat Transfer 114, n. 2 (1 maggio 1992): 425–33. http://dx.doi.org/10.1115/1.2911291.

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Heat transfer measurements were made during nucleate boiling of R-113 from a bundle of 15 electrically heated, smooth copper tubes arranged in an equilateral triangular pitch. The bundle was designed to simulate a portion of a refrigeration system flooded-tube evaporator. The outside diameter of the tubes was 15.9 mm, and the tube pitch was 19.1 mm. Five of the tubes that were oriented in a vertical array on the centerline of the bundle were each instrumented with six wall thermocouples to obtain an average wall temperature and a resultant average heat transfer coefficient. All tests were performed at atmospheric pressure. The majority of the data were obtained with increasing heat flux to study the onset of nucleate boiling and the influence of surface “history” upon boiling heat transfer. Data taken during increasing heat flux showed that incipient boiling was dependent upon the number of tubes in operation. The operation of lower tubes in the bundle decreased the incipient boiling heat flux and wall superheat of the upper tubes, and generally increased the boiling heat transfer coefficients of the upper tubes at low heat fluxes where natural convection effects are important. The boiling data confirmed that the average heat transfer coefficient for a smooth-tube bundle is larger than obtained for a single tube.

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Ayub, Zahid, e Adnan Ayub. "Replacing Two Shell-and-Plate Exchangers With a Single Special Design Shell-and-Tube Ammonia-Flooded Evaporator at a Major Food Plant—A Case Study". Heat Transfer Engineering 37, n. 12 (2 febbraio 2016): 1075–78. http://dx.doi.org/10.1080/01457632.2015.1104198.

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Ubara, Tsutomu, Hitoshi Asano e Katsumi Sugimoto. "Heat Transfer Enhancement of Falling Film Evaporation on a Horizontal Tube by Thermal Spray Coating". Applied Sciences 10, n. 5 (29 febbraio 2020): 1632. http://dx.doi.org/10.3390/app10051632.

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Falling film evaporators are gaining popularity as substitutes to typical flooded evaporators because of their low refrigerant charge. It is important to form and keep a thin liquid film on the heat transfer surface to ensure their high heat transfer performance. In this study, as a heat transfer enhancement surface, a fine porous surface processed using thermal spray coating was applied to a smooth copper tube with an outer diameter of 19.05 mm. Heat transfer coefficients of falling film evaporation on a single horizontal tube were experimentally evaluated using the HFC-134a refrigerant. The experiments were performed at a saturation temperature of 20 °C with the heat flux ranging from 10 to 85 kW·m−2 and for film Reynolds numbers up to 673. The study aimed to clarify the effect of the coating on the heat transfer characteristics of falling film evaporation. The results revealed that the coating could suppress partial dry out and enhance nucleate boiling in the falling film. The maximum heat transfer enhancement factor was 5.2 in the experimental range. It was further noted that the effect of the coating was especially strong under a low heat flux condition.

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Nielsen, D. L., e A. J. Chick. "Flood-mediated changes in aquatic macrophyte community structure". Marine and Freshwater Research 48, n. 2 (1997): 153. http://dx.doi.org/10.1071/mf96090.

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Sixteen artificial billabongs on the floodplain of the River Murray, New South Wales, were surveyed over a 14-month period to observe the effect of different hydrological regimes on the development of aquatic macrophyte communities. The billabongs were initially planted with Vallisneria sp. and Myriophyllum papillosum Orch. in November 1994, then flooded. The 16 billabongs were divided into four treatments: summer flood, spring flood, permanent inundation, and a control treatment that was initially flooded and then allowed to vary in depth with rainfall and evaporation. The plant communities were surveyed on six occasions between April 1995 and June 1996, and percentage cover was estimated on each sampling occasion. Fourteen aquatic macrophyte taxa were recorded over the study period. Billabongs in the permanent and summer treatments exhibited less plant diversity than did billabongs in the control or spring treatments. Terrestrial plants germinated on the exposed areas in both spring and control treatments, but not in the other treatments.

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Rebelo, L.-M., G. B. Senay e M. P. McCartney. "Flood Pulsing in the Sudd Wetland: Analysis of Seasonal Variations in Inundation and Evaporation in South Sudan". Earth Interactions 16, n. 1 (1 febbraio 2012): 1–19. http://dx.doi.org/10.1175/2011ei382.1.

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Abstract Located on the Bahr el Jebel in South Sudan, the Sudd is one of the largest floodplain wetlands in the world. Seasonal inundation drives the hydrologic, geomorphological, and ecological processes, and the annual flood pulse is essential to the functioning of the Sudd. Despite the importance of the flood pulse, various hydrological interventions are planned upstream of the Sudd to increase economic benefits and food security. These will not be without consequences, in particular for wetlands where the biological productivity, biodiversity, and human livelihoods are dependent on the flood pulse and both the costs and benefits need to be carefully evaluated. Many African countries still lack regional baseline information on the temporal extent, distribution, and characteristics of wetlands, making it hard to assess the consequences of development interventions. Because of political instability in Sudan and the inaccessible nature of the Sudd, recent measurements of flooding and seasonal dynamics are inadequate. Analyses of multitemporal and multisensor remote sensing datasets are presented in this paper, in order to investigate and characterize flood pulsing within the Sudd wetland over a 12-month period. Wetland area has been mapped along with dominant components of open water and flooded vegetation at five time periods over a single year. The total area of flooding (both rain and river fed) over the 12 months was 41 334 km2, with 9176 km2 of this constituting the permanent wetland. Mean annual total evaporation is shown to be higher and with narrower distribution of values from areas of open water (1718 mm) than from flooded vegetation (1641 mm). Although the exact figures require validation against ground-based measurements, the results highlight the relative differences in inundation patterns and evaporation across the Sudd.

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WEBB, R. L., e T. V. V. R. APPARAO. "Performance of Flooded Refrigerant Evaporators with Enhanced Tubes". Heat Transfer Engineering 11, n. 2 (gennaio 1990): 29–44. http://dx.doi.org/10.1080/01457639008939727.

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Fernández-Seara, José, e Jaime Sieres. "Ammonia–water absorption refrigeration systems with flooded evaporators". Applied Thermal Engineering 26, n. 17-18 (dicembre 2006): 2236–46. http://dx.doi.org/10.1016/j.applthermaleng.2006.03.011.

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Li, Xinhu, e Fengzhi Shi. "The Effect of Flooding on Evaporation and the Groundwater Table for a Salt-Crusted Soil". Water 11, n. 5 (13 maggio 2019): 1003. http://dx.doi.org/10.3390/w11051003.

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Soil salt crusts have been shown to have a strong influence on evaporation and water movement in soils, and this has attracted considerable attention. However, there is little information available on these processes during flooding. The objective of this study was to investigate the evaporation rate, variation in the groundwater table, and soil water content of salt-crusted soil flooded by five floodwater depths: 2 mm (Treatment A), 6 mm (Treatment B), 10 mm (Treatment C) 14 mm (Treatment D), and 18 mm (Treatment E). The experiments were carried out using repacked homogeneous silt loam soil columns in the laboratory. The experimental results showed that salt crust formation led to a low evaporation rate. The salt crust tended to form a dome, and some breakage occurred when the salt crust was dry. The broken crust increased the evaporation rate, indicating that the evaporation occurred below the crust. The soil moisture did not significantly change in the soil profile from 20 to 70 cm during the experimental period, which indicated that the existence of the evaporation front located in a layer very close to the surface. The evaporation rate rapidly increased when floodwater was added to the soils and returned to its previous low value after the salt crust reformed. However, before the salt crust reformed, there was a total water loss of 2.1, 4.3, 6.6, 10.1, and 13.8 mm for treatments A, B, C, D, and E, respectively, indicating that only a portion of the floodwater evaporated; another portion of the floodwater was discharged into the groundwater, causing the groundwater table to rise, although only by a small amount (6 mm). Therefore, the groundwater recharge caused by flooding should be considered. Otherwise, groundwater consumption may be overestimated.

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32

Browne, M. W., e P. K. Bansal. "Heat transfer characteristics of boiling phenomenon in flooded refrigerant evaporators". Applied Thermal Engineering 19, n. 6 (giugno 1999): 595–624. http://dx.doi.org/10.1016/s1359-4311(98)00056-8.

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33

Minetto, Silvia, e Ezio Fornasieri. "An innovative system for feeding once-through evaporators in flooded conditions". Applied Thermal Engineering 31, n. 2-3 (febbraio 2011): 370–75. http://dx.doi.org/10.1016/j.applthermaleng.2010.09.026.

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34

Wu, Dawei, Wenhui Zhang, Li Tang e Cunquan Zhang. "A New Integrated Scheme for Urban Road Traffic Flood Control Using Liquid Air Spray/Vaporization Technology". Sustainability 12, n. 7 (31 marzo 2020): 2733. http://dx.doi.org/10.3390/su12072733.

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With the rapid progress of urbanization, cities’ demands for traffic flood control are steadily on the increase, and people are gradually paying more attention to traffic safety and environmental issues. Considering the considerable convenience and service ability of liquid air and corresponding products, people have begun to switch to using liquid air as an emergency coolant. However, this air’s cryogenic operation and vigorous vaporization expansion restricts its widespread application. Our study explores innovative applications based on liquid air spray/evaporation icing and natural melting, which can be applied to urban flood protection. This study also includes a brief introduction to the nature of liquid air and road icing, a conceptual design based on liquid air flash evaporation (for urban flood protection), and the modeling and solving of natural road ice melting. This paper introduces many innovative key technologies, which include the rapid solidification of floods to form emergency ice dams or diversion channels and the application of liquid air spray to form icy roads for the temporary passage of small cars or pickup trucks. Additionally, the economic estimations are performed by using downtown traffic flood control in Wuhan as an example to showcase our innovative scheme for applying liquid air spray/vaporization for urban traffic flooding control, which is practical, pollution free, and cost effective. Our innovative scheme will be promising for flood control in modern cities.

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35

Allen, Scott T., Michele L. Reba, Brandon L. Edwards e Richard F. Keim. "Evaporation and the subcanopy energy environment in a flooded forest". Hydrological Processes 31, n. 16 (28 giugno 2017): 2860–71. http://dx.doi.org/10.1002/hyp.11227.

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36

Gupte, Neelkanth, e Ralph Webb. "Shell-Side Boiling in Flooded Refrigerant Evaporators Part I: Integral Finned Tubes". HVAC&R Research 1, n. 1 (1 gennaio 1995): 35–47. http://dx.doi.org/10.1080/10789669.1995.10391307.

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37

Mahindawansha, Amani, Christoph Külls, Philipp Kraft e Lutz Breuer. "Investigating unproductive water losses from irrigated agricultural crops in the humid tropics through analyses of stable isotopes of water". Hydrology and Earth System Sciences 24, n. 7 (22 luglio 2020): 3627–42. http://dx.doi.org/10.5194/hess-24-3627-2020.

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Abstract. Reliable information on water flow dynamics and water losses via irrigation on irrigated agricultural fields is important to improve water management strategies. We investigated the effect of season (wet season and dry season), irrigation management (flooded and non-flooded), and crop diversification (wet rice, dry rice, and maize) on soil water flow dynamics and water losses via evaporation during plant growth. Soil water was extracted and analysed for the stable isotopes of water (δ2H and δ18O). The fraction of evaporation losses were determined using the Craig–Gordon equation. For dry rice and maize, water in shallow soil layers (0 to 0.2 m) was more isotopically enriched than in deeper soil layers (below 0.2 m). This effect was less pronounced for wet rice but still evident for the average values at both soil depths and seasons. Soil water losses due to evaporation decreased from 40 % at the beginning to 25 % towards the end of the dry season. The soil in maize fields showed stronger evaporation enrichment than in rice during that time. A greater water loss was encountered during the wet season, with 80 % at the beginning of the season and 60 % at its end. The isotopic enrichment of ponding surface water due to evaporation was reflected in the shallow soils of wet rice. It decreased towards the end of both growing seasons during the wet and the dry season. We finally discuss the most relevant soil water flow mechanisms, which we identified in our study to be those of matrix flow, preferential flow through desiccation cracks, and evaporation. Isotope data supported the fact that unproductive water losses via evaporation can be reduced by introducing dry seasonal crops to the crop rotation system.

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38

Vieira, Nayara Paula Andrade, Eduardo De Oliveira Bueno, Silvio Bueno Pereira e Carlos Rogério de Mello. "Water footprint of the Sobradinho hydropower plant, Northeastern Brazil". Ambiente e Agua - An Interdisciplinary Journal of Applied Science 13, n. 3 (29 maggio 2018): 1. http://dx.doi.org/10.4136/ambi-agua.2134.

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Hydroelectricity is responsible for the greatest fraction of the electric energy generated in Brazil. The water footprint of hydropower plants (WFP) is an important indicator of the sustainable and efficient use of water resources. In this context, WFP of the Sobradinho Hydropower Plant was determined for the period from 2003 to 2012, taking into account the reservoir’s historical variation for the flooded area. To accomplish this, monthly series of electric energy production, flooded area, evaporation and evapotranspiration rates were used. Average gross and net evaporation were 2,031 and 1,577 mm year-1, respectively. The average power generation of this facility in the analyzed period was 462 MW, and the flooded area of its reservoir presented an average value of 3,054 km². Based on the monthly data, the gross and net water footprints were, respectively, 417 and 325 m³ GJ-1. Based on these results, it can be concluded that the changes in the reservoir’s area exert direct and important influence on the WFP estimates of the Sobradinho hydropower plant. The WFP estimates in this study were different from other studies that adopted a constant value of 4,214 km² for this reservoir’s area, which is taken based on the normal water level of the plant operation.

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39

Voigt, Claudia, Daniel Herwartz, Cristina Dorador e Michael Staubwasser. "Triple oxygen isotope systematics of evaporation and mixing processes in a dynamic desert lake system". Hydrology and Earth System Sciences 25, n. 3 (10 marzo 2021): 1211–28. http://dx.doi.org/10.5194/hess-25-1211-2021.

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Abstract. This study investigates the combined hydrogen deuterium and triple oxygen isotope hydrology of the Salar del Huasco, an endorheic salt flat with shallow lakes at its centre that is located on the Altiplano Plateau, N Chile. This lacustrine system is hydrologically dynamic and complex because it receives inflow from multiple surface and groundwater sources. It undergoes seasonal flooding, followed by rapid shrinking of the water body at the prevailing arid climate with very high evaporation rates. At any given point in time, ponds, lakes, and recharge sources capture a large range of evaporation degrees. Samples taken between 2017 and 2019 show a range of δ18O between −13.3 ‰ and 14.5 ‰, d-excess between 7 ‰ and −100 ‰, and 17O-excess between 19 and −108 per meg. A pan evaporation experiment conducted on-site was used to derive the turbulence coefficient of the Craig–Gordon isotope evaporation model for the local wind regime. This, along with sampling of atmospheric vapour at the salar (-21.0±3.3 ‰ for δ18O, 34±6 ‰ for d-excess and 23±9 per meg for 17O-excess), enabled the accurate reproduction of measured ponds and lake isotope data by the Craig–Gordon model. In contrast to classic δ2H–δ18O studies, the 17O-excess data not only allow one to distinguish two different types of evaporation – evaporation with and without recharge – but also to identify mixing processes between evaporated lake water and fresh flood water. Multiple generations of infiltration events can also be inferred from the triple oxygen isotope composition of inflow water, indicating mixing of sources with different evaporation histories. These processes cannot be resolved using classic δ2H–δ18O data alone. Adding triple oxygen isotope measurements to isotope hydrology studies may therefore significantly improve the accuracy of a lake's hydrological balance – i.e. the evaporation-to-inflow ratio (E / I) – estimated by water isotope data and application of the Craig–Gordon isotope evaporation model.

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Insua-Costa, Damián, Gonzalo Miguez-Macho e María Carmen Llasat. "Local and remote moisture sources for extreme precipitation: a study of the two catastrophic 1982 western Mediterranean episodes". Hydrology and Earth System Sciences 23, n. 9 (24 settembre 2019): 3885–900. http://dx.doi.org/10.5194/hess-23-3885-2019.

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Abstract. Floods and flash floods are frequent in the south of Europe resulting from heavy rainfall events that often produce more than 200 mm in less than 24 h. Even though the meteorological conditions favourable for these situations have been widely studied, there is a lingering question that still arises: what humidity sources could explain so much precipitation? To answer this question, the regional atmospheric Weather Research and Forecasting (WRF) model with a recently implemented moisture tagging capability has been used to analyse the main moisture sources for two catastrophic flood events that occurred during the autumn of 1982 (October and November) in the western Mediterranean area, which is regularly affected by these types of adverse weather episodes. The procedure consists in selecting a priori potential moisture source regions for the extreme event under consideration, and then performing simulations using the tagging technique to quantify the relative contribution of each selected source to total precipitation. For these events we study the influence of four possible potential sources: (1) evaporation in the western Mediterranean; (2) evaporation in the central Mediterranean; (3) evaporation in the North Atlantic; and (4) advection from the tropical and subtropical Atlantic and Africa. Results show that these four moisture sources explain most of the accumulated precipitation, with the tropical and subtropical input being the most relevant in both cases. In the October event, evaporation in the western and central Mediterranean and in the North Atlantic also had an important contribution. However, in the November episode tropical and subtropical moisture accounted for more than half of the total accumulated rainfall, while evaporation in the western Mediterranean and North Atlantic played a secondary role and the contribution of the central Mediterranean was almost negligible. Therefore, remote sources were crucial: in the October event they played a similar role to local sources, whereas in the November case they were clearly dominant. In both episodes, long-distance moisture transport from the tropics and subtropics mostly occurred in mid-tropospheric layers, via well-defined moisture plumes with maximum mixing ratios at medium levels.

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41

Shamseddin, M. A. H., T. Hata, A. Tada, M. A. Bashir e T. Tanakamaru. "Estimation of flooded area in the Bahr El-Jebel basin using remote sensing techniques". Hydrology and Earth System Sciences Discussions 3, n. 4 (24 luglio 2006): 1851–77. http://dx.doi.org/10.5194/hessd-3-1851-2006.

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Abstract. In spite of the importance of Sudd (swamp) area estimation for any hydrological project in the southern Sudan, yet, no abroad agreement on its size, due to the inaccessibility and civil war. In this study, remote sensing techniques are used to estimate the Bahr El-Jebel flooded area. MODIS-Terra (Moderate Resolution Imaging Spectroradiometer) level 1B satellite images are analyzed on basis of the unsupervised classification method. The annual mean of Bahr El-Jebel flooded area has been estimated at 20 400 km2, which is 96% of Sutcliffe and Park (1999) estimation on basis of water balance model prediction. And only, 53% of SEBAL (Surface Energy Balance Algorithm for Land) model estimation. The accuracy of the classification is 71%. The study also found the swelling and shrinkage pattern of Sudd area throughout the year is following the trends of Lake Victoria outflow patterns. The study has used two evaporation methods (open water evaporation and SEBAL model) to estimate the annual storage volume of Bahr El-Jebel River by using a water balance model. Also the storage changes due time is generated throughout the study years.

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42

Baldocchi, Dennis, Sara Knox, Iryna Dronova, Joe Verfaillie, Patty Oikawa, Cove Sturtevant, Jaclyn Hatala Matthes e Matteo Detto. "The impact of expanding flooded land area on the annual evaporation of rice". Agricultural and Forest Meteorology 223 (giugno 2016): 181–93. http://dx.doi.org/10.1016/j.agrformet.2016.04.001.

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43

Le, Tuan Hoang, e Dung Anh To. "A Modified Semi-parametric Regression Model For Flood Forecasting". Science and Technology Development Journal 18, n. 2 (30 giugno 2015): 95–105. http://dx.doi.org/10.32508/stdj.v18i2.1078.

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In recent years, inundation, one of natural calamities, occurs frequently and fiercely. We are sustained severe losses in the floods every year. Therefore, the development of control methods to determine, analyze, model and predict the floods is indispensable and urgent. In this paper, we propose a justified semiparametric regression model for flood water levels forecasting. The new model has three components. The first one is parametric elements of the model. They are water level, precipitation, evaporation, air-humidity and groundmoisture values, etc. There is a complex connection among these parametrics. Several innovated regression models have been offered and experimented for this complicated relationship. The second one is a non-parametric ingredient of our model. We use the Arnak S. Dalalyan et al.’s effective dimension-reduction subspace algorithm and some modified algorithms in neural networks to deal with it. They are altered back-propagation method and ameliorated cascade correlation algorithm. Besides, we also propose a new idea to modify the conjugate gradient one. These actions will help us to smooth the model’s non-parametric constituent easily and quickly. The last component is the model’s error. The whole elements are essential inputs to operational flood management. This work is usually very complex owing to the uncertain and unpredictable nature of underlying phenomena. Flood-waterlevels forecasting, with a lead time of one and more days, was made using a selected sequence of past water-level values observed at a specific location. Time-series analytical method is also utilized to build the model. The results obtained indicate that, with a new semiparametric regression one and the effective dimension-reduction subspace algorithm, together with some improved algorithms in neural network, the estimation power of the modern statistical model is reliable and auspicious, especially for flood forecasting/modeling.

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44

Cai, GX, JR Freney, E. Humphreys, OT Denmead, M. Samson e JR Simpson. "Use of surface films to reduce ammonia volatilization from flooded rice fields". Australian Journal of Agricultural Research 39, n. 2 (1988): 177. http://dx.doi.org/10.1071/ar9880177.

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This paper presents the results of experiments on the control of ammonia volatilization from flooded rice by the use of surface films of organic compounds.Preliminary experiments in evaporation pans, 1.2 m diameter, buried in an upland field of mown pasture, showed that ammonia volatilization from water could be reduced by applications of surface films of long chain alcohols; the effect increased with increasing length of carbon chain.The most effective way to add the film was to dissolve the long chain alcohol in ethanol, and to distribute the solution on the surface of the water.In an experiment in a flooded rice field, additions of cetyl alcohol dissolved in ethanol significantly reduced the rate of ammonia emission and total nitrogen loss. The effect was short-lived, probably due to microbiological decomposition of the cetyl alcohol and dispersion of the surface film by strong winds.

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45

Bullock, A., e M. Acreman. "The role of wetlands in the hydrological cycle". Hydrology and Earth System Sciences 7, n. 3 (30 giugno 2003): 358–89. http://dx.doi.org/10.5194/hess-7-358-2003.

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Abstract. It is widely accepted that wetlands have a significant influence on the hydrological cycle. Wetlands have therefore become important elements in water management policy at national, regional and international level. There are many examples where wetlands reduce floods, recharge groundwater or augment low flows. Less recognised are the many examples where wetlands increase floods, act as a barrier to recharge, or reduce low flows. This paper presents a database of 439 published statements on the water quantity functions of wetlands from 169 studies worldwide. This establishes a benchmark of the aggregated knowledge of wetland influences upon downstream river flows and groundwater aquifers. Emphasis is placed on hydrological functions relating to gross water balance, groundwater recharge, base flow and low flows, flood response and river flow variability. The functional statements are structured according to wetland hydrological type and the manner in which functional conclusions have been drawn. A synthesis of functional statements establishes the balance of scientific evidence for particular hydrological measures. The evidence reveals strong concurrence for some hydrological measures for certain wetland types. For other hydrological measures, there is diversity of functions for apparently similar wetlands. The balance of scientific evidence that emerges gives only limited support to the generalised model of flood control, recharge promotion and flow maintenance by wetlands portrayed throughout the 1990s as one component of the basis for wetland policy formulation. That support is confined largely to floodplain wetlands, while many other wetland types perform alternate functions – partly or fully. This paper provides the first step towards a more scientifically defensible functional assessment system. Keywords: wetlands, hydrological functions, flood reduction, groundwater recharge, low flows, evaporation

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46

Kgabi, Nnenesi A., Eliot Atekwana, Johanna Ithindi, Martha Uugwanga, Kay Knoeller, Lebogang Motsei, Manny Mathuthu, Gideon Kalumbu, Hilma R. Amwele e Rian Uusizi. "Isotopic composition and elemental concentrations in groundwater in the Kuiseb Basin and the Cuvelai-Etosha Basin, Namibia". Proceedings of the International Association of Hydrological Sciences 378 (29 maggio 2018): 93–98. http://dx.doi.org/10.5194/piahs-378-93-2018.

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Abstract. We assessed environmental tracers in groundwater in two contrasting basins in Namibia; the Kuiseb Basin, which is a predominantly dry area and the Cuvelai-Etosha Basin, which is prone to alternating floods and droughts. We aimed to determine why the quality of groundwater was different in these two basins which occur in an arid environment. We analysed groundwater and surface water for the stable isotope ratios of hydrogen (δ2H) and oxygen (δ18O) by cavity ring-down spectroscopy and metals by inductively coupled plasma mass spectrometry. The δ2H and δ18O of surface water in the Cuvelai-Etosha Basin plot on an evaporation trend below the global meteoric water line (GMWL) and the local meteoric water line (LMWL). The δ2H and δ18O of some groundwater samples in the Cuvelai-Etosha Basin also plot on the evaporation trend, indicating recharge by evaporated rain or evaporated surface water. In contrast, the δ2H and δ18O of groundwater samples in the Kuiseb Basin plot mostly along the GMWL and the LMWL, indicating direct recharge from unevaporated rain or unevaporated surface water. Fifty percent of groundwater samples in the Cuvelai-Etosha Basin was potable (salinity < 1 ppt) compared to 79 % in the Kuiseb Basin. The high salinity in the groundwater of the Cuvelai-Etosha Basin does not appear to be caused by evaporation of water (evapo-concentration) on surface prior to groundwater recharge, but rather by the weathering of the Kalahari sediments. The low salinity in the Kuiseb Basin derives from rapid recharge of groundwater by unevaporated rain and limited weathering of the crystalline rocks. The order of abundance of cations in the Kuiseb Basin is Na > K > Ca > Mg vs. Na > Mg > Ca > K for the Cuvelai-Etosha Basin. For metals in the Kuiseb Basin the order of abundance is Fe > Al > V > As > Zn vs. Al > Fe > V> As > Zn for the Cuvelai-Etosha Basin. The relative abundance of cations and metals are attributed to the differences in geology of the basins and the extent of water-rock interaction. Our results show that the quality of groundwater in Cuvelai-Etosha Basin and Kuiseb Basin which vary in the extent of aridity, is controlled by the extent of water-rock interaction at the surface and in the groundwater aquifer.

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Kim, Nae-Hyun. "Performance Analysis of the Flooded Refrigerant Evaporators for Large Tonnage Compression-Type Refrigerators Using Alternative Refrigerants". Journal of the Korea Academia-Industrial cooperation Society 17, n. 6 (30 giugno 2016): 18–25. http://dx.doi.org/10.5762/kais.2016.17.6.18.

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48

Zhuang, S. Y., B. Yin e Z. L. Zhu. "Simulating the effectiveness of surface film on water evaporation and ammonia volatilisation". Soil Research 40, n. 7 (2002): 1243. http://dx.doi.org/10.1071/sr01027.

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The application of surface films to flooded rice fields is one of the most effective measures of controlling ammonia volatilisation for improving nitrogen use efficiency. The feasibility of using a surface film is determined to some extent by the longevity of the effectiveness and this has never been estimated accurately in the field. The concept of half-life was introduced to estimate the effective life of a surface film by calculation from its effect on water evaporation. A simple laboratory experiment was carried out to validate the usefulness of the half-life concept. The results showed that effects on ammonia volatilisation could be quantified using a logistic equation based on the half-life concept.

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Yi, Lu, Bin Yong, Junxu Chen, Ziyan Zheng e Ling Li. "Impact of 4D-Var Data Assimilation on Performance of the Coupled Land–Atmosphere Model WRF–TOPX: A Case Study of a Flood Event in the Wangjiaba Watershed, China". Journal of Hydrometeorology 22, n. 3 (marzo 2021): 689–701. http://dx.doi.org/10.1175/jhm-d-20-0161.1.

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AbstractTo assess the impact of four-dimensional variational (4D-Var) data assimilation on the performance of a land–atmosphere coupled model, the satellite precipitation of the Integrated Multisatellite Retrievals for Global Precipitation Measurement (IMERG) was assimilated into the Weather Research Forecast (WRF) Model, and the WRF was coupled to the hydrological model TOPX. Precipitation and evaporation were both investigated as connecting elements in the coupled model WRF–TOPX. Differing in whether the 4D-Var data assimilation and evaporation were applied, one control experiment and four experiments were performed to simulate a historical flood event that happened in the Wangjiaba watershed in eastern China. The key hydrological variables of precipitation, potential evaporation, soil moisture, and discharge in the studied flood process were evaluated. The results showed that 1) the 4D-Var data assimilation with the IMERG could reduce both the overestimations of the WRF-predicted precipitation and potential evaporation; 2) the applied 4D-Var data assimilation could improve considerably the accuracy of the soil moisture and discharges from the coupled model WRF–TOPX; and 3) evaporation was also an important factor to influence the net precipitation to affect the performance of the coupled land–atmosphere model. With the two connecting elements of precipitation and evaporation, the 4D-Var assimilation based on IMERG could improve the Nash–Sutcliffe coefficient of the coupled model WRF–TOPX from 0.483 to 0.521 at the hourly scale. These investigations can provide important implications for the land–atmosphere coupling with both the precipitation and evaporation and using the 4D-Var data assimilation with IMERG for flood simulation at a large scale.

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Boluwade, A., e P. F. Rasmussen. "Frequency of floods in a changing climate: a case study from the Red River in Manitoba, Canada". Proceedings of the International Association of Hydrological Sciences 371 (12 giugno 2015): 83–88. http://dx.doi.org/10.5194/piahs-371-83-2015.

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Abstract. Spring flooding in the Red River basin is a recurrent issue in the Province of Manitoba, Canada. There have been a number of flood events in recent years and climate change has been suggested as a potential cause. This paper employs a relatively simple model for predicting changes in the frequency distribution of annual spring peak discharge of the Red River as a response to increased GHG concentrations. A regression model is used to predict spring peak flow from antecedent precipitation in the previous fall, winter snow accumulation, and spring precipitation. Data from the Coupled Model Intercomparison Project – Phase 5 (CMIP5) are used to estimate changes in the predictor variables and this information is then employed to derive flood distributions for future climate conditions. Most climate models predict increased precipitation during winter months but this trend is partly offset by a shorter snow accumulation period and higher winter evaporation rates. The means and medians of an ensemble of 16 climate models do not suggest a particular trend toward more or less frequent floods of the Red River. However, the ensemble range is relatively large, highlighting the difficulties involved in estimating changes in extreme events.

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