Academic literature on the topic 'Thermally active panels'
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Journal articles on the topic "Thermally active panels"
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Kalús, Daniel, Mária Kurčová, Zuzana Straková, and Matej Kubica. "Thermaly Active Interior Panels with an Integrated Active Area." Slovak Journal of Civil Engineering 29, no. 1 (March 1, 2021): 42–47. http://dx.doi.org/10.2478/sjce-2021-0007.
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Abstract Panels with an integrated active area can be used for interior applications for walls, ceilings and floor heating, and alternatively as a wet or dry type of construction. At present, most panels with an integrated active area are made of gypsum boards with milled channels and embedded pipes. Some manufacturers already supply these panels with thermal insulation (Radwan et al., 2021; Zhang et al., 2020). Certain limitations, mainly regarding the diameter and material of the pipes, apply to the panels with channels milled in the gypsum board and embedded pipes. These limitations are closely related to the high cost of such panels and to the limited heat/cooling output. The disadvantages of these panels are eliminated by the construction of a thermal insulation panel with active thermal protection for application with an active heat transfer control system (indoor thermally active panel (ITAP)) in accordance with European Patent No. EP 2 572 057 B1 (Kalús, 2011).
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Kalús, Daniel, Zuzana Straková, and Matej Kubica. "Parametric Study of Heating and Cooling Capacity of Interior Thermally Active Panels." Periodica Polytechnica Mechanical Engineering 65, no. 3 (July 5, 2021): 269–79. http://dx.doi.org/10.3311/ppme.17570.
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ITAP panels - interior thermally active panels with an integrated active surface in an innovative way combine existing building and energy systems into one compact unit, and thus create combined building and energy systems. These are building structures with an internal energy source. Low heat losses, respectively, thermal gains predestine for energy-efficient buildings the application of low-temperature heating/high-temperature cooling systems such as large-area floor, wall, and ceiling heating/cooling. The main benefit of ITAP panels is the possibility of unified and prefabricated production. At the same time, they represent a reduction of production costs due to their technological process of production, a reduction of assembly costs due to a reduction of steps during implementation on the construction site and a reduction of implementation time due to their method of application.
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Quesada Allerhand, José, Ongun Berk Kazanci, and Bjarne W. Olesen. "Energy and thermal comfort performance evaluation of PCM ceiling panels for cooling a renovated office room." E3S Web of Conferences 111 (2019): 03020. http://dx.doi.org/10.1051/e3sconf/201911103020.
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The performance of suspended ceiling panels with phase change materials (PCM) for comfort cooling applications in office rooms was studied. The panel consisted of a metal casing, which encapsulates the PCM. Water can circulate through the pipes embedded in the panel to influence the latent energy storage of the material. To evaluate the performance of the PCM panels, a comparison with an all-air system and a thermally active building system (TABS) was made. Using TRNSYS 17, a recently renovated room in the Technical University of Denmark was modelled. The room was simulated during the cooling season with each of the three cooling systems in which the thermal environment and the corresponding energy use were determined. Operative temperature was maintained between 22°C to 27°C at least 90% of the occupied period with each system. Similarities were observed between the PCM and TABS systems. Energy savings of 15% and peak cooling power reduction of 30% compared with the all-air system were observed. This study proved the common claim that PCM ceiling panels and TABS perform similar in terms of the created thermal indoor environment and energy savings, as well in terms of heat removal from the indoor space. Therefore, PCM ceiling panels could be used as an alternative for TABS in renovation projects while providing similar benefits to TABS.
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Safin, Ruslan Rushanovich, Aigul Ravilevna Shaikhutdinova, Ruslan Khasanshin, Shamil Mukhametzyanov, and Albina Safina. "Increasing the Strength of the Glue Line in the Production of Thermally Modified Wood Paneling." Coatings 11, no. 2 (February 20, 2021): 253. http://dx.doi.org/10.3390/coatings11020253.
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This work is devoted to the study of the effect of ultraviolet rays for the surface activation of pine wood thermally modified at temperatures of 180−240 °C in order to increase the surface roughness, enhance the wettability of thermal wood and the adhesive strength of the glue in the production of wood block furniture panels. Studies were carried out to measure the contact angle of wettability of thermally modified wood samples of pine, as a result of which it was determined that the ultraviolet treatment process contributes to an increase in the adhesion properties of the surface layer of thermally modified wood by more than 13% due to the reactivity of ultraviolet rays to oxidize and degrade ligno-containing wood products. At the same time, the most active process of surface activation takes place during 60 min of ultraviolet irradiation of wood with a total irradiation of at least 125 W/cm2. It was revealed that the combined effect of two-stage wood processing, including preliminary volumetric thermal modification followed by surface ultraviolet treatment, causes an increase in the moisture resistance of glued wood products by 24%. So, if the strength of the glue seam when gluing natural wood samples after boiling decreased by 46%, then the samples that underwent two-stage processing showed a decrease only by 22%. In connection with the results obtained, an improved technology for the production of furniture boards for the manufacture of moisture-resistant wood products is proposed.
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Binar, Tomáš, Jiří Švarc, Stanislav Rolc, Petr Dostál, and Michal Šustr. "The Use of Resistant Glass in Special Agricultural Machinery and the Logistic Support Depending on Operating Temperatures." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 65, no. 4 (2017): 1121–27. http://dx.doi.org/10.11118/actaun201765041121.
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The paper is concerned with quality assessment of bullet‑resistant glass in relation to ambient temperatures. The measurement results provided below may be drawn on in the field of logistics when transport, special as well as special agricultural machinery are operated at fluctuating temperatures. In the paper, data from shooting tests, monitoring the projectile velocity, penetration through the glass and projectile fragmentation at various ambient temperatures, is presented. For perfect protection of agricultural machine operators not only the bullet‑resistance of glass panels, but also their further use in work is of great importance. Hence, emphasis is put on active safety of these machinery, where a perfect transparency of the bullet‑resistant panels is one of crucial factor. In the paper, the extent of damaged areas is compared; these are divided into three zones according to significantly differing temperatures. The paper results may have influence on agricultural machinery in thermally extreme areas.
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Keskküla, Kadri, Tambet Aru, Mihkel Kiviste, and Martti-Jaan Miljan. "Hygrothermal Analysis of Masonry Wall with Reed Boards as Interior Insulation System." Energies 13, no. 20 (October 9, 2020): 5252. http://dx.doi.org/10.3390/en13205252.
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When the masonry walls of buildings under heritage protection need to be restored and thermally improved, the only option is to use an interior insulation system. This is also the riskiest method of insulating walls in cold climates. Capillary active interior insulation systems have been proven to be the most reliable, minimizing the risk of mold growth and decay caused by condensation. They have also been proven to be less risky in wind-driven rain. The building studied is situated in a heritage-conservation area in downtown Tartu, Estonia, and therefore cannot be insulated from the exterior. This paper compares the hygrothermal performance of four different interior insulation systems with and without a heating cable and vapor barrier. In the first case, Isover Vario KM Duplex UV was placed between reed panels. In the second case, reed panels were used without the vapor barrier. Data loggers were applied between the reed panels and the original wall and inside the room to measure temperature and relative humidity in one-hour intervals. Exterior temperature and relative humidity values were taken from the Estonian University of Life Sciences Institute of Technology weather service station. In addition to the measurements taken in the case study building, calculations were made using heat-air-moisture (HAM) Delphin software to simulate the situation. The use of a smart vapor retarder (Isover Vario KM Duplex UV) with reed panels in the interior insulation system reduced the relative humidity level inside the wall. The vapor retarder improved the drying-potential compared to the interior insulation system without the vapor barrier.
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Šimko, Martin, Michal Krajčík, and Ondřej Šikula. "Radiant wall cooling with pipes arranged in insulation panels attached to facades of existing buildings." E3S Web of Conferences 111 (2019): 03013. http://dx.doi.org/10.1051/e3sconf/201911103013.
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Radiant systems are being increasingly used for space heating and cooling of buildings. The contemporary research of radiant systems addresses mainly floor and ceiling structures. Research regarding the possibilities of their incorporation in wall structures is lacking, despite their potential advantages. This study addresses a radiant wall system manufactured according to a patent. The patented design involves panels that consist of pipes arranged in milled channels in thermal insulation. The potential advantage of this system is the fact that the thermally active panels can be attached to the facades of existing buildings as a part of their retrofit. Thereby, only minor interventions on the interior side of the retrofitted buildings are needed. To test and improve the design of the wall system, laboratory measurements and computer simulations were performed on a wall fragment for its operation under summer conditions. The results indicate a significant potential for improvement of the patented design by addressing the imperfections in the contact between pipe and wall. Inserting a metal fin between pipe and wall enhanced the cool distribution within the wall fragment considerably. From the three materials of the metal fin considered, using copper led to highest values of the cooling output, followed by aluminium. For these two metals the effect of increasing the thickness of the fin on the cooling output was small. On the contrary, the fin made of steel was the least efficient in terms of cool distribution. In this case the cooling output was most sensitive to the thickness of the fin.
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Kalús, Daniel, Daniela Koudelková, Veronika Mučková, Martin Sokol, and Mária Kurčová. "Contribution to the Research and Development of Innovative Building Components with Embedded Energy-Active Elements." Coatings 12, no. 7 (July 19, 2022): 1021. http://dx.doi.org/10.3390/coatings12071021.
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The research described in this study focuses on the innovation and optimization of building envelope panels with integrated energy-active elements in the thermal barrier function. It is closely related to developing and implementing the prototype prefabricated house IDA I with combined building-energy systems using renewable energy sources. We were inspired by the patented ®ISOMAX panel and system, which we have been researching and innovating for a long time. The thermal barrier has the function of eliminating heat loss/gain through the building envelope. By controlling the heat/cold transfer in the thermal barrier, it is possible to eliminate the thickness of the thermal insulation of the building envelope and thus achieve an equivalent thermal resistance of the building structure that is equal to the standard required value. The technical solution of the ISOMAX panel also brings, besides the use of the thermal barrier function, the function of heat/cold accumulation in the load-bearing part of the building envelope. Our research aimed to design and develop a panel for which the construction would be optimal in terms of thermal barrier operation and heat/cold accumulation. As the production panels in the lost formwork of expanded polystyrene (according to the patented system) proved to be too complicated and time consuming, and often showed shortcomings from a structural point of view, the next goal was to design a new, statically reliable panel construction with integrated energy-active elements and a time-saving, cost-effective, unified production directly in the panel factory. In order to develop and design an innovative panel with integrated energy-active elements, we analyzed the composition of the original panel and designed the composition of the innovative panel. We created mathematical–physical models of both panels and analyzed their energy potential. By induction and an analog form of formation, we designed the innovative panel. Based on the synthesis of the knowledge obtained from the scientific analysis and the transformation of this data, most of the building components and all the panels with integrated energy-active elements were manufactured directly in the prefabrication plant. Subsequently, the prototype of the prefabricated house IDA I was realized. The novelty of our innovative building envelope panel solution lies in the panel’s design, which has a heat loss/gain that is 2.6 times lower compared to the ISOMAX panel.
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Sun, Guo, and Yuan Gui Sun. "Thermal-Structural Analysis of Ni-Based Alloy Panel with Active Cooling Thermal Protection System." Applied Mechanics and Materials 644-650 (September 2014): 4718–21. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.4718.
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In hypersonic environments, the development of aircraft engine presents the mitigation of the extreme thermal environment inside the combustion chamber. This paper establishes the capabilities for combustor panel design. By given the key loading and boundary conditions of the panel structure, the thermal structural analysis determines temperatures and stresses and the optimization improves panel’s robustness subject to thermal mechanical loads. A parametric sweep analysis is carried and the results give the optimal value of the panel face thickness.
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Simonova, O. S., A. O. Chulkov, V. P. Vavilov, and S. B. Suntsov. "Active thermal testing of hyperthermoconductive panels." Russian Journal of Nondestructive Testing 53, no. 6 (June 2017): 453–56. http://dx.doi.org/10.1134/s1061830917060080.
Full textDissertations / Theses on the topic "Thermally active panels"
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Jin-WeiGuo and 郭晉維. "The Heat Transfer and Thermal Stress Analysis of an Acting-type Heat Retention Panel and a Hot Blast Stove." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/27wha3.
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碩士國立成功大學
機械工程學系
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In the steel process, production of molten iron and improvement of the mechanical properties of the strip steel have been a focus for a long time. Therefore, the numerical simulation was utilized to analyze the heat retention devices in hot strip rolling process and the hot blast stove used in iron making process. In the heat retention panel study, high temperature transfer bars are transported by conveyors through the heat retention panel in order to decrease the temperature difference between the head and the tail of the transfer bars. A three-dimensional numerical model of a traditional passive heat retention panel was developed to investigate the temperature difference between the head and the tail of the transfer bars. According to the simulation results, it was found that the temperature difference in the transfer bar at FET position between the numerical simulation and the in-situ data was about 1.53%. Based on the developed model, a three-dimensional numerical model of the acting-type heat retention panel was constructed in order to predict whether the temperature difference decreases during the heat retention process. According to the numerical results of the acting-type heat retention panel model, providing the heat fluxes on the upper surface of the radiation plate can effectively reduce the temperature difference. In the hot blast stove study, a three-dimensional finite element model was developed to investigate the thermal stress distribution. The numerical results showed that the maximum thermal stress of the refractories was about 25.0 MPa which occurred on the neck of checker chamber and combustion chamber, inner refractories of connection and blast pipes. The maximum thermal deformation about 249 mm occurred on the neck of checker chamber. The maximum thermal deformation on the dome of checker chamber and combustion chamber was about 77 mm and 72 mm, respectively. Furthermore, the shell can also generate stress and deformation because of the temperature difference.
Books on the topic "Thermally active panels"
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Faddegon, Stephen, Ephrem O. Olweny, and Jeffrey A. Cadeddu. Ablative technologies for renal cancer. Edited by James W. F. Catto. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199659579.003.0087.
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Nearly two-thirds of newly detected renal masses are clinical stage 1, with T1a tumours accounting for 60% of the newly detected stage 1 tumours. Guideline panels convened by the American Urological Association and the European Association of Urology recommend nephron-sparing surgery as the gold standard treatment for small renal masses, with active surveillance and thermal ablation recommended as alternative strategies in select patients. However, there is a dearth of studies directly comparing outcomes for energy-based ablation to those for traditional surgical treatments for small renal masses, and future prospective randomized trials will be invaluable in this regard. Ongoing research in renal tumour ablation targets several areas, including but not limited to achieving larger ablation sizes, decreasing morbidity, and development of novel technologies for renal tumour ablation.
Book chapters on the topic "Thermally active panels"
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Mukherjee, Ragini, N. K. Gopinath, V. Vignesh, Anupam Purwar, and D. Roy Mahapatra. "Thermal Analysis of Scramjet Combustor Panel with Active Cooling Using Cellular Materials." In 30th International Symposium on Shock Waves 1, 239–44. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-46213-4_39.
Full textConference papers on the topic "Thermally active panels"
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Kelley, Leah, Amy M. Bilton, and Steven Dubowsky. "Enhancing the Performance of Photovoltaic Powered Reverse Osmosis Desalination Systems by Active Thermal Management." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62717.
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Reverse osmosis (RO) is a well-known process for desalinating seawater and brackish groundwater. Desalination is energy-intensive, so using photovoltaic (PV) panels to power the process is an attractive and cost-effective concept, especially for community-scale systems. Increasing the system efficiency will lower the total cost of water produced, making the systems more economically competitive for a greater number of geographic locations. It is noted in this paper that the amount of water produced by a PV-powered RO (PVRO) system can be increased if the temperatures of the solar panel and the reverse osmosis feed water are actively managed. For a given level of solar radiation, a photovoltaic panel produces more power at a lower temperature. Also, for a given power, an RO system produces more clean water at a higher input (feed) water temperature. An active thermal management system is needed to exploit these complementary characteristics by cooling the solar panel and warming the RO feed water, increasing the amount of fresh water produced. This can be accomplished by running the RO feed water through a heat exchanger attached to the back of the solar panel, cooling it. Furthermore, the ability to cool the solar panels permits the addition of low-cost, flat-plate concentrating mirrors to be used with the PV panels, which further increases the PV power output. The flow of the water through the respective units must be actively controlled as there are limits for the maximum temperatures of both the RO water and PV panels. In this paper, a concept for an active PVRO thermal control system is presented. Simulations and experimental results show the effectiveness of this approach. In experiment, a 57% increase in fresh water production was achieved. These experimental results agree well with simulation models.
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Song, Hongwei, Mingjun Li, Chenguang Huang, and Xi Wang. "Thermal-Structural Design of Actively-Cooled Panels Reinforced by Light-Weight Truss Cores." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63352.
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This paper focuses on thermal-structural analysis and lightweight design of actively-cooled panels reinforced by low density lattice-framed material (LFM) truss cores. Numerical models for actively-cooled panels are built up with parametric codes to perform the coupled thermal-structural analysis, considering the internal thermal environment of convective heat transfer in the combustor and convective heat transfer in the cooling channel, and internal pressures from the combustion gas and the coolant. A preliminary comparison of the LFM truss reinforced actively-cooled panel and the non-reinforced panel demonstrates that the thermal-structural behavior is significantly improved. Then, an optimization procedure is carried out to find the lightest design while satisfying thermal deformation and plastic strain constraints, with thicknesses of face sheets and topology parameters of LFM truss as design variables. The optimization result demonstrates that, compared with the non-reinforced actively-cooled panels, weight reduction for the panel reinforced by LFM truss may reach 19.6%. We have also fabricated this type of actively-cooled panel in the laboratory level, and the specimen shows good mechanical behaviors.
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Lamson, Joel A., and Stuart W. Baur. "Solar Thermal Electric Panel (STEP): Thermal and Energy Testing." In ASME 2008 2nd International Conference on Energy Sustainability collocated with the Heat Transfer, Fluids Engineering, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/es2008-54354.
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The concept of combining both solar thermal and electric systems is not new yet the limited use and further development needed has been noted by both the Department of Energy in the U.S. [1] and the EU Coordination Action PV-Catapult in Europe [2]. These reports and the university’s solar house entry in the Department of Energy’s 2005 Solar Decathlon provided the opportunity for research and development of a hybrid roof system that combined both photovoltaics with a wet solar thermal system. The main goal of this research was to design and develop a hybrid roof system based on previous research. Once designed then build a prototype model for the purpose of performance analysis with the final stage being the implementation in the university’s solar house entry into the 2005 solar decathlon. This paper discusses the hybrid roof design and performance analysis. The design and development was initialized by a group of students and advisors from both the University of Missouri-Rolla and Crowder College with the intent to use the hybrid system as part of the solar houses in the upcoming solar decathlons. Previous research studies on hybrid roof systems have shown increased performance however the differences in the systems studied vary in their setups and use of materials. In the case of this study a series of copper tubes were integrated into a metal seam roof with an amorphous silicon panel encased in low iron glass. This experiment encompassed almost 160 square feet of hybrid Solar Thermal Electric Panel (STEP) system panels and performance data acquired was used for input to computer simulation software to optimize the system for application. Based on experimental tests the STEP system yielded overall efficiency of 50%. This is compared to a separate thermal and electric system with an estimated 26% for the same roof area. The glazed versus unglazed analysis yielded a glazed panel reducing the PV collection by 23% yet increasing the thermal collection by approximately 200%. In conclusion this paper will discuss experimental performance analysis on the STEP system thermal and overall outcomes.
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Balaban, Murat, Giovanna Ferrentino, Milena Ramirez, Maria L. Plaza, and Thelma Calix. "Review of Dense Phase Carbon Dioxide Application to Citrus Juices." In ASME 2008 Citrus Engineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/cec2008-5407.
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The United States is the second largest citrus producer in the world. Florida and California are the two major producing states. While oranges from California are mainly used for fresh fruit consumption, more than 90% of oranges produced in Florida are processed to juice (FAO 2008). Consumers demand high quality and convenient products with natural flavor and taste, and appreciate the “fresh” perception of minimally processed juices. They also look for safe, natural, and healthy products without additives and preservatives. New processing technologies promise to meet all these demands without compromising food safety. Commercial orange juice is thermally processed to inactivate pectinesterase (PE) and spoilage organisms. Active PE causes clarification of orange juice by cloud loss, which is considered a quality defect (Boff et al. 2003). Thermal processing can be detrimental to the organoleptic and nutritional qualities of the juice (Sloan 1995), so the development of non-thermal technologies (Barbosa-Canovas et al. 1998) is desirable in the citrus juice industry. Dense phase carbon dioxide (DPCD) is a non-thermal technology that can inactivate certain micro-organisms and enzymes at temperatures low enough to avoid the thermal effects of traditional pasteurization. This technology relies on the chemical effect of CO2 on micro-organisms and enzymes. DPCD pasteurization technology is commercially available. Most of the commercialization efforts so far have been from Praxair Inc. (Burr Ridge, IL). Based on technology licensed from the University of Florida (Balaban et al. 1988, 1998), Praxair developed a continuous system which uses the DPCD process as a non-thermal alternative to thermal pasteurization (Connery et al. 2005). This system has been commercialized under the Trade Mark “Better Than Fresh (BTF).” To date, Praxair has constructed four mobile BTF units for processing about 1.5 liters per minute for demonstration purposes. In addition, a commercial scale unit of 150 liters per minute was also constructed (Connery et al. 2005) and tested at an orange juice processing plant in Florida. There are other commercialization efforts. The excellent taste of the juice processed with this new technology was demonstrated in three independent sensory panels that compared juice treated with this system to that of fresh squeezed juice. In all the tests, no difference could be detected. It is important that CO2 is completely saturated in the juice if DPCD is to be successful. Saturation (equilibrium solubility) depends on the pressure, temperature, and composition of the juice. Until recently, the exact amount of CO2 to be used in DPCD processing was unknown since solubility data was unavailable at different pressures, temperatures, and juice compositions, and an excess amount was used. To optimize the use of CO2 in this non-thermal process, new equipment has been developed to measure the solubility of CO2 in liquid systems and juices. The objective of this paper is to present a general review of the applications of DPCD to citrus juices and to introduce the use of new equipment developed at the University of Florida to determine the solubility of CO2 in citrus juices. Paper published with permission.
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Jiang, X., and S. Mahadevan. "An Intelligent Damage Detection System for Thermal Protection Panels with Active Sensors." In 11th Biennial ASCE Aerospace Division International Conference on Engineering, Science, Construction, and Operations in Challenging Environments. Reston, VA: American Society of Civil Engineers, 2008. http://dx.doi.org/10.1061/40988(323)157.
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Schollenberger, Frederick S., Frank Kreith, and Jay Burch. "Geographical Limitations on Integral-Collector-Storage Collectors due to Collector Freeze." In ASME 2012 6th International Conference on Energy Sustainability collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/es2012-91306.
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A major challenge for solar water heaters is to provide heat at a cost comparable to or lower than conventional fuels. Since the price of a passive integral-collector-storage (ICS) solar water heater has historically been less than that for active systems with freeze protection, they can potentially heat water at a lower cost. However, ICS panels are subject to freeze damage, as the collector generally has metal tubes carrying pressurized water that can freeze and burst. In order to delineate the geographical areas where ICS panels can be deployed safely, it is necessary to experimentally characterize the conditions causing freeze damage, to develop a model relating the freeze behavior to climatic conditions, to validate that model with experimental data, and to run the model against long-term weather data across the U.S. Two variations of an ICS panel and/or their bare tubes were tested in a walk in freezer and subjected to freezing conditions until freeze damage occurred. The units tested include both a single and double glazed tubular ICS panel. Key data includes the volume expansion of the tube(s) at burst and the collector loss coefficient near 0 degrees C. Under freezing conditions the insulated supply/return lines would freeze solid initiating a pressure-buildup and eventual burst in the collector tubes due to further internal freezing. An additional test on the single glazed unit was also conducted in which heat tape was installed on the inlet and outlet pipes to prevent them from freezing, which increases the freeze tolerance of the panel by forcing small internal interconnection pipes to freeze solid before damage occurs. Existing models for ICS thermal performance were modified to incorporate the freezing process, and have been validated with the experimental data. The validated models were used to predict regions of the country that are safe for installing the ICS panels. Simulations were run using 30 years of weather data available for all TMY2 sites, and maps were created to illustrate regions of safe installation throughout the US for both the with and without heat tape scenarios for the two ICS models. A correlation using record minimum temperature was developed to generalize the maps to any location for which the record minimum is known. The maps show quantitatively the expected conclusions: 1) that double glazing and higher insulation will extend the safe region; and 2) that the use of heat tape on the inlet and outlet pipes significantly increases the region in which ICS panels can be safely installed in the US.
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Conrardy, C., T. D. Huang, D. Harwig, P. Dong, L. Kvidahl, N. Evans, and A. Treaster. "Practical Welding Techniques to Minimize Distortion in Lightweight Ship Structures." In SNAME Maritime Convention. SNAME, 2005. http://dx.doi.org/10.5957/smc-2005-p27.
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The trend in both military and commercial shipbuilding is the increased use of thin steel to reduce weight and improve performance. Complex panel structures have thickness transitions for weight and structural optimization with multiple inserts ranging from 5 to 45 mm. Welding practices developed for thicker plate can result in significant out-of-plane distortion when applied to thin-plate structures. Buckling distortion of complex lightweight panels has resulted in a significant negative effect on manufacturing cost and production throughput, limiting the shipbuilders’ ability to produce innovative ship designs. High fitting and welding costs are the consequence of this large welding distortion. This problem is exacerbated as the fairness requirements are tightened. New methods are needed to control distortion when welding thinner materials. To tackle the distortion problems, in 2002 Northrop Grumman Ship Systems initiated a multiyear program to develop distortion-control technology for complex panels. This paper reports the results of a study to develop “best practices” for welding of lightweight structures. Control of welding distortion for thin structures requires control of each welding operation from butt-welding of plates through to unit assembly. A general philosophy was applied to minimize welding heat input while maximizing restraint during unit construction. To achieve this, the following techniques were evaluated: * Increasing restraint during each welding operation, * Improving fitting practice, * Weld sequencing and, * Minimizing welding heat input. * Additionally, an active distortion mitigation approach, known as Transient Thermal Tensioning, was investigated for reduction of buckling distortion during thin-panel longitudinal stiffener welding. A series of tests were performed to evaluate various distortion control approaches and to optimize production processes. The culmination of the project will involve demonstrating best practices in the production of thin steel structures. A plan is also being developed for implementing the most advantageous approaches into production.
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Rakow, Joseph, and Anthony Waas. "Thermal Buckling of Metal Foam Sandwich Panels for Actively Cooled Thermal Protection Systems." In 45th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2004. http://dx.doi.org/10.2514/6.2004-1710.
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McCarthy, Patrick T., Stephen L. Hodson, Timothy D. Sands, and Timothy S. Fisher. "Carbon Nanotube Interfaces for Magneto Thermoelectric Actuation." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22810.
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Magneto thermoelectric generator cell technology uses the ferromagnetic phase transition of gadolinium to drive the movement of a diaphragm ‘shuttle’ whose mechanical energy can be converted to electrical form and which enhances heat transfer through both conduction and convection. This paper describes the thermal behavior of gadolinium foils used in magneto thermoelectric generator cells that, in conjunction with a planar array of similar devices, would form a thermal backplane to a solar photovoltaic panel. In this scenario, the backplane operates as a self-powered cooling device that can simultaneously convert thermal energy to electrical energy as well as improve photovoltaic efficiency through active cooling. This form of energy harvesting and enhancement shows the potential of increasing the energy density of silicon photovoltaic panels. The synthesis and characterization of thermal interfaces applied to the gadolinium shuttles and hot/cold substrates are described. Carbon nanotube arrays are implemented as the thermal interfaces, and their performance under static conditions is assessed. Optimization of the carbon nanotube interfaces on the gadolinium shuttles is achieved using photoacoustic experiments for measuring the thermal interface resistances above and below the gadolinium foil. Carbon nanotube growth studies on gadolinium demonstrated a reduction in thermal interface resistances from 28.8 ± 2.1 mm2K/W to as low as 17.9 ± 0.8 mm2K/W. Initial design, fabrication, and experimental techniques and results are presented in this paper.
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Oh, Il-Kwon, and In Lee. "Aerothermoelastic Analysis of Cylindrical Piezolaminated Shells Using Multifield Layerwise Theory." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33621.
Full textAbstract:
For the aerothermoelastic analysis of cylindrical piezolaminated shells, geometrically nonlinear finite elements based on the multi-field layerwise theory have been developed. Present multi-field layerwise theory describes zigzag displacement, thermal and electric fields providing a more realistic multi-physical description of fully and partially piezolaminated panels. By applying a Hans Krumhaar’s supersonic piston theory, supersonic flutter analyses are performed for the cylindrical piezolaminted shells subject to thermal and piezoelectric loads. The possibility to increase flutter boundary and reduce thermoelastic deformations of piezolaminated panels is examined using piezoelectric actuation. Results show that active piezoelectric actuation can effectively increase the critical aerodynamic pressure by retarding the coalescence of flutter modes and compensating thermal stresses.