Bridge monitoring studies indicate that the quasi-static response of a bridge, while dependent on various input forces, is affected predominantly by variations in temperature. In many structures, the quasi-static response can even be approximated as equal to its thermal response. Consequently, interpretation of measurements from quasi-static monitoring requires accounting for the thermal response in measurements. Developing solutions to this challenge, which is critical to relate measurements to decision-making and thereby realize the full potential of SHM for bridge management, is the main focus of this research. This research proposes a data-driven approach referred to as temperature-based measurement interpretation (TB-MI) approach for structural performance evaluation of bridges based on continuous bridge monitoring. The approach characterizes and predicts thermal response of structures by exploiting the relationship between temperature distributions across a bridge and measured bridge response. The TB-MI approach has two components - (i) a regression-based thermal response prediction (RBTRP) methodology and (ii) an anomaly detection methodology. The RBTRP methodology generates models to predict real-time structural response from distributed temperature measurements. The anomaly detection methodology analyses prediction error signals, which are the differences between predicted and real-time response to detect the onset of anomaly events. In order to generate realistic data-sets for evaluating the proposed TB-MI approach, this research has built a small-scale truss structure in the laboratory as a test-bed. The truss is subject to accelerated diurnal temperature cycles using a system of heating lamps. Various damage scenarios are also simulated on this structure. This research further investigates if the underlying concept of using distributed temperature measurements to predict thermal response can be implemented using physics-based models. The case study of Cleddau Bridge is considered. This research also extends the general concept of predicting bridge response from knowledge of input loads to predict structural response due to traffic loads. Starting from the TB-MI approach, it creates an integrated approach for analyzing measured response due to both thermal and vehicular loads. The proposed approaches are evaluated on measurement time-histories from a number of case studies including numerical models, laboratory-scale truss and full-scale bridges. Results illustrate that the approaches accurately predicts thermal response, and that anomaly events are detectable using signal processing techniques such as signal subtraction method and cointegration. The study demonstrates that the proposed TB-MI approach is applicable for interpreting measurements from full-scale bridges, and can be integrated within a measurement interpretation platform for continuous bridge monitoring.

Tunable nanostructures have many important uses in thin film applications. Tunability can be achieved by creating a film that has features that respond to external stimuli, such as temperature, humidity, or pH. However, the response can vary greatly between a confined and unconfined case. In the case of confined materials, this response can be greatly reduced, even completely suppressed, which indicates that separate studies must be conducted on confined states in order to better understand their use for real applications. Microgels have been previously shown to have exceptional responsive properties that depend on their chemical structure and synthesis. Unlike solid thin hydrogel films that respond on the order of hours, microgels arrange on a surface with no external force and create a highly porous layer which responds rapidly, on the order of minutes, to outside stimuli. These properties make microgels a promising candidate for use in tunable thin films. Although the responsive properties of microgels have been extensively studied in solution and unconfined films, this is not indicative of conditions that would most likely have the microgels placed between two stiffer layers of material. Microgels have been shown to respond to glucose concentration, temperature, pH, and light. One well-studied microgel is poly-N-isopropylacrylamide copolymerized with Acrylic Acid (pNIPAM-co-AAC). These microgels use the thermal response of pNIPAM combined with the pH sensitivity of pAAC to create a dually-responsive material. To study the effects of confinement on pNIPAM-co-AAC microgels, we encapsulated these particles within bi-layers of poly(allylamine hydrochloride)-poly(sodium 4-styrenesulfonate) (PAH-PSS) in order to simulate their response within a polyelectrolyte material. Our samples were prepared with a method called tilt-drying, which creates a microgel concentration gradient. This allowed us to study both the confinement caused by the multi-layered film as well as the effects of microgels on each other. Our results have shown that the change in particle height is unaffected by the concentration of the film, but the thermal response of pNIPAM-co-AAC microgels is significantly suppressed by the encapsulation of microgels into nanoscale layers.

Approved for public release; distribution is unlimited / The development of a dynamic computational model capable of predicting, with the requisite design certainty, the transient thermal response of jet vane thrust control systems has been undertaken. The modeling and simulation procedures utilized are based on the concept that the thermal processes associated with jet vane operation can be put into a transfer function form commonly found in the discipline of automatic controls. Well established system identification methods are employed to formulate and verify the relationships between the various gains and frequencies of the transfer function model and experimental data provided by Naval Weapons Center, China Lake. / http://archive.org/details/modelingofjetvan00hatz / Lieutenant, United States Navy

In 2010, the Ground Source Heat Pumps (GSHPs) market in the European Union went up over one million (1 014 436 units at the end of 2010 according to EUROBSERV’ER 2011). In 2011, it was estimated around 1.25 million according to Bayer et al. (2012). With more than 378 000 units installed in 2010, according to the Swedish heat pump association (SVEP), the Swedish GSHPs market was the first in the EU. As for the French GSHPs market, it was estimated to 151 938 units in service in 2010, which propelled France at the third rank in the EU. However, despite a relatively important number of GSHPs installed in the whole EU, since 2008 GSHP sales have shrank. Even Sweden which has been the most competitive country sees its GSHP sales decline in the first quarter of 2012 (EUROBSERV’ER 2011). This report is the achievement of my Master of Science Thesis project. It also represents the end of my studies at INSA Lyon in France and concludes my degree in Energetic and Environment Engineering. This report deals with the improvement of a heat injection apparatus which is available at KTH (Royal Institute of Technology). This equipment is better known as Thermal Response Test (TRT) apparatus. This kind of equipment improves Borehole Heat Exchangers (BHE) design in terms of size and cost benefits. This technology is generally used to design GSHP installations in both domestic and industrial purposes. It allows to determine really important thermal BHE parameters: the thermal conductivity of the ground and the borehole thermal resistance. The report covers a theoretical description of TRT experiments, the reasons and objectives of such a project, the apparatus design and its construction. The last part is dedicated to a first experimental laboratory results and some problems met during the project course.

This thesis investigates the validity of the standard thermal response test (TRT) results when performed on a series of boreholes (string). The typical TRT consists of subjecting a single borehole to a constant heat injection rate to obtain the temperature response in the ground which can then be used to determine the ground thermal conductivity. When completed on a single borehole, the results may be analyzed with the line source theory, since the assumption of a single line heat source is valid. For multiple boreholes, the assumption of a single line source becomes invalid if the spacing between the boreholes is small enough for borehole thermal interaction to occur. Moreover, for boreholes that are charged in series, heat transfer from the horizontal pipes that connect the vertical boreholes may also influence the ground thermal response. This thesis takes an in-depth look at the different factors that affect the results of TRTs performed on borehole strings. Different analysis methods are implemented to determine areas of improvement for determining the thermal conductivity of the soil surrounding the borehole string. For the analysis, the infinite line source (ILS) model and a model developed using TRNSYS 18 were used to determine the effective thermal conductivity. The results show that TRNSYS is unable to accurately model a TRT performed on a borehole string. The horizontal pipe model within TRNSYS proved to have significant fundamental issues, as the effective thermal conductivity is greatly underestimated with values of 1.2±0.1W/mK and the results of increasing the horizontal length both increased and decreased the effective thermal conductivities. The results from the ILS demonstrate that an effective thermal conductivity of 1.7±0.2W/mK is an appropriate estimate of the soil at the BTES field tested, as the borehole string with the furthest spacing between boreholes gave an effective thermal conductivity of 1.7W/mK. Performing multiple thermal response tests within the same BTES field also provided evidence of the need to implement multiple TRTs as common practise. The testing presented shows that the effective thermal conductivity can vary within ±0.2W/mK within the same relative location. With better knowledge of the thermal properties within the BTES field location comes the opportunity for improved planning of operation and control of thermal distribution within the field. This would be especially beneficial when dealing with seasonal BTES fields / Thesis / Master of Applied Science (MASc)

<p> Poly(N-isopropylacrylamide) (PNIPAM) has attracted much attention as a thermo-responsive polymer. However, the molecular weight (MW) dependence of its phase transition temperature is still controversial. This situation is largely due to the difficulty in synthesizing narrow-disperse PNIPAM. We have addressed the challenge and developed an atom transfer radical polymerization (ATRP) method to prepare narrow-disperse PNIPAM with moderate to high conversions, using branched alcohols as solvents. Aqueous solutions of these narrow-disperse PNIPAMs showed a dramatic decrease of the phase transition temperature with increasing molecular weight, as measured by turbidimetry and differential scanning calorimetry. Four other series of narrow-disperse PNIPAM with well-controlled molecular weights and with end groups of varying hydrophobicity were also synthesized by ATRP using the corresponding initiators, which enabled us to resolve the MW and end group effects. All the four series of samples showed an inverse molecular weight (MW) dependence of their phase transition temperature. The magnitude of the MW dependence decreased when using more hydrophobic end groups. The end groups were observed to have effects on the cloud point temperature, on the shape of the cloud point curves, and on the enthalpy of the phase transition.</p> / Thesis / Master of Science (MSc)

Žemės šilumos siurblių sistemos surenka žemės šilumą, dažniausiai vertikaliu U formos gręžinio šilumokaičiu. U formos gręžinio šilumokaičio našumas priklauso nuo šiluminių žemės savybių, taip pat nuo gręžinyje naudojamo skiedinio ar užpildo. Siekiant, kad Žemės šilumos siurblių sistemos pasiteisintų, projektuojant reikia atsižvelgti į geologinių struktūrų šiluminį laidumą ir gręžinio šilumokaičio šiluminę varžą. Šio darbo tikslas buvo nustatyti šilumos siurblio, naudojančio grunto šilumą, pritaikymo individualioje sodyboje siurblio techninis ir ekonominis įvertinimas. Nustatyta, kad investicijos projektui įgyvendinti, kai gyvenamajam pastatui šildyti ir buitiniam karštam vandeniui ruošti šildymo sezono metu šilumą gamina šilumos siurblys, naudojantis grunto šilumą, palyginti su tiesioginiu elektros naudojimu pastatui šildyti ir buitiniam karštam vandeniui ruošti, atsiperka per 6,3 metus. Šiluminės reakcijos testas padeda nustatyti šiluminį žemės laidumą (λ) gręžinio šilumokaičio įrengimo vietoje, bei efektyvią gręžinio šilumokaičio šiluminę varžą (Rb). Pagrindinis tikslas buvo suderinti gręžinio šilumokaitį su žemės sąlygomis, taip pat nustatyti gręžinio gylio poveikį (60 m: VB2; 90 m: VB3). / Ground source heat pump systems exchange heat with the ground, often through a vertical, U-tube, borehole heat exchanger. The performance of this U-tube borehole heat exchanger depends on the thermal properties of the ground formation, as well as grout or backfill in the borehole. The design and economic probability of ground source heat pump systems need the thermal conductivity of geological structure and thermal resistance of borehole heat exchanger. An economic and technical evaluation of the heat pump, which is using ground heat, in individual homestead. It was found that the investment for this project, when heat pump using ground heat is used to heat residential building and domestic hot water in heating season, compared with the use of direct electric heating of buildings and domestic hot water payback within 6.3 years. Thermal response test method allows the in-situ determination of the thermal conductivity (l) of the ground formation in the vicinity of a borehole heat exchanger, as well as the effective thermal resistance (Rb) of this latter. The main goal has been to determine same in-situ ground type of borehole heat exchanger, including the effect of borehole’s depths (60 m: VB2; 90 m: VB3).

No description available.

Ground Source Heat Pumps (GHSPs) is a relevant application and around 3 million installations are setting up at the beginning of 2010 (IEA ECES Annex 21). The improvements in GSHPs are currently focused on the optimization of the system and the reduction of costs installations. The thermal conductivity of the ground and thermal resistance of the Borehole Heat Exchanger (BHE) are important design parameters for Borehole Thermal Energy Storage (BTES) systems. The Thermal Response Test (TRT), which has been used up to now in the GHE design, only allows estimating mean values for thermal conductivity of the surrounding ground and borehole resistance. However, the ground thermal conductivity and borehole thermal resistance may present local variation along the borehole depth. For improving conventional TRT, the optical fiber technology is applied to collect information about the temperature profiles in the borehole. Thermal Response Test (TRT) logs the inlet and outlet fluid temperatures; meanwhile, the Distributed Thermal Response Test (DTRT) carries out a profile of the temperature along the borehole depth, in this case with fiber optic cables. This Master of Science Thesis focuses on the comparison and analysis of DTRT measurements in a U-pipe borehole in order to estimate the thermal conductivity and the borehole thermal resistance along the borehole. The comparison and the analysis are carried out by: •Comparing the differences of TRT results depending on the heat power rate considered – constant and by steps-. •Comparing the results from two different resolution Distributed Test Sensing (DTS) equipments: Halo and Sentinel DTS. •Comparing the differences of TRT results as depending on the analytical procedure based on the line source theory: line source model and line source approximation.

Nowadays Ground Source Heat Pumps (GSHP) are widely used to provide heating and/or cooling as well as domestic hot water in commercial and residential buildings. The Swedish GSHPs market is the first one in the European Union with more than 378,000 units installed until 2010 according to the Swedish Heat Pump Association (SVEP). This thesis focuses on the improvement of a Thermal Response Test (TRT) apparatus available at KTH Royal Institute of Technology – Energy Technology Department. This equipment aims at improving Borehole Heat Exchanger (BHE) design in terms of size. Its key purpose is to evaluate two main BHE properties: the ground thermal conductivity and the borehole thermal resistance. A new command software is developed in order to control the TRT equipment and run TRT measurements. This new software is developed using Python as programming language and replaces an older program which needed LabVIEW to run. The TRT command software designed in this thesis provides the user with a simple and user-friendly interface to control each device of the equipment. Measurements are exported and saved to files which can be open with both Microsoft Excel and the analysis tool also developed in this thesis. The stand-alone evaluation tool can be used to analyse TRT and/or DTRT measurements. This analysis tool helps the user to compute large amount of data with few data manipulation and low computation time. Model parameters and TRT/DTRT measurement can be imported from files into it and different fitting settings are available to run the optimization, i.e. account for baseline variations (early activities in the borehole, different optimization periods, analysis during thermal recovery of the ground, single/multi-sectional analysis along the depth, among others). This report covers a theoretical description of TRT experiments and its models, the objectives of such a project and the development of the control and evaluation tools.