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Mortar beams incorporating carbon nanofibers (CNFs), which were synthesized in situ on Portland cement particles, were used to produce nanomodified Portland cement sensors (SmartCem sensors). SmartCem sensors exhibited an electrical response comparable to a thermistor with a temperature coefficient of resistivity of − 0.0152/ °C. The highest temperature sensing was obtained for the SmartCem sensor, which contained ~ 0.271 wt.% of CNFs. The calculated temperature sensitivity was approximately 11.76% higher in comparison with the mortar beam containing only unmodified Portland cement. SmartCem sensors were used to monitor the cement hydration in large-scale self-compacting concrete beams. The measurements were conducted after casting for 7 days. Additionally, commercially available thermocouple and humidity sensors were used as references. The results showed that changes in electrical resistivity measured by the SmartCem sensor were well aligned with the ongoing hydration processes., Validerad;2023;Nivå 2;2023-12-04 (joosat);Full text license: CC BYThis article has previously appeared as a manuscript in a thesis.

This work presents a continuous volumetric indoor air temperature measurement scheme using PMUTs (piezoelectric micromachined ultrasonic transducers). Advancements as compared to state-of-art works include: (1) 'volumetric' temperature monitoring instead traditional 'pointwise' temperature information; (2) accurate temperature readings spanning an operational distance of 5 m as validated by a commercial thermometer for 3 days; and (3) capable of detecting global average temperature and local temperature events by installing networked/grid PMUT pairs. This innovative sensing technique could be applicable for the precision control of future building/living environments.

Mortar sensors were fabricated as beams incorporating different amounts of carbon nanofibers (CNFs) synthesized in-situ on cement particles. Changes in electrical resistivity were measured and compared to recorded changes in compressive stress, temperature, and humidity. Sensing mechanisms and corresponding models were developed. The findings of the study indicate that the piezoresistive effect is influenced by the critical concentration of CNFs inside the composite matrix and the tunneling effect. In addition, water absorption and desorption, as well as the amount of chemically bound water played an important role in humidity sensing. Thermal fluctuation-induced tunneling conduction was dominant for the temperature sensitivity., Validerad;2024;Nivå 2;2024-06-03 (joosat);Funder: Skanska Sverige;Full text license: CC BY

Enhancing sediment accumulation monitoring techniques in sewers will enable a better understanding of the build-up processes to develop improved cleaning strategies. Thermal sensors provide a solution to sediment depth estimation by passively monitoring temperature fluctuations in the wastewater and sediment beds, which allows evaluation of the heat-transfer processes in sewer pipes. This study analyses the influence of the flow conditions on heat-transfer processes at the water-sediment interface during dry weather flow conditions. For this purpose, an experimental campaign was performed by establishing different flow, temperature patterns, and sediment depth conditions in an annular flume, which ensured stable flow and room-temperature conditions. Numerical simulations were also performed to assess the impact of flow conditions on the relationships between sediment depth and harmonic parameters derived from wastewater and sediment-bed temperature patterns. Results show that heat transfer between water and sediment occurred instantaneously for velocities greater than 0.1 m/s, and that sediment depth estimations using temperature-based systems were barely sensitive to velocities between 0.1 and 0.4 m/s. A depth estimation accuracy of +/- 7 mm was achieved. This confirms the ability of using temperature sensors to monitor sediment build-up in sewers under dry weather conditions, without the need for flow monitoring., Validerad;2024;Nivå 2;2024-07-10 (joosat);Funder: Xunta de Galicia (Conselleria de Cultura, Educacion e Universidade) (ED481B-2021-082); Full text license: CC BY 4.0

Temperature sensing and monitoring play a vital role in various applications. Non-invasive, item-level temperature sensing methods that require no direct line of sight with the measuring object are attractive. This paper presents such a temperature sensing method using commodity RFID tags with no infrastructure changes. RFID tags are widely deployed for product identification purposes. We explore the possibility of leveraging the RSSI measurements from commodity RFID tags for temperature sensing. Essentially, we model a relationship between the temperature and the relative permittivity of a material in terms of RSSI. Our method can measure temperature in the range of 22°C to 60°C and achieves a measurement accuracy of 2°C with a mean error of 1.5°C.

Ongoing developments in science and technology require temperature measurements at increasingly higher spatial resolutions. Nanocrystals with temperature-sensitive luminescence are a popular thermometer for these applications offering high precision and remote read-out. Here, we demonstrate that ratiometric luminescence thermometry experiments may suffer from systematic errors in nanostructured environments. We place lanthanide-based luminescent nanothermometers at controlled distances of up to 600 nm from a Au surface. Although this geometry supports no absorption or scattering resonances, distortion of the emission spectra of the thermometers due to the modified density of optical states results in temperature read-out errors of up to 250 K. Our simple analytical model explains the effects of thermometer emission frequencies, experimental equipment, and sample properties on the magnitude of the errors. We discuss the relevance of our findings in several experimental scenarios. Such errors do not always occur, but they are expected in measurements near reflecting interfaces or scattering objects.

We present the first report on reflectometric optical fiber sensing based on mechanically induced cascaded long-period grating (LPG) structure. This method utilizes in-house designed mechanical casings and a bare fiber. When a fiber is sandwiched between the casings and pressed by tightening screws, an LPG is induced due to a photo-elastic effect. By exploiting Fresnel refection at a fiber end, a cascaded LPG structure can be implemented using a single LPG, enabling reflectometric configuration. When this sensor is subjected to external physical processes, the attenuation bands change clearly, and their shift can be used for non-destructive evaluations. We show experimentally that this sensor can measure loads of up to 10 N without producing any permanent change in the fiber properties, indicating its pressure sensing capability. We also show that this sensor can potentially measure strain and temperature. In our experiments, the strain and temperature sensitivities are 9.4 nm/% and 0.045 nm/°C, respectively.

In this work, we demonstrate the usability of a fully-2D-material based device consisting of MoS2/WSe2 heterojunction encapsu-lated by hBN and contacted by graphene as temperature sensor for linear temperature measurement at cryogenic temperatures. More precisely, temperatures in the range of 10 K up to 300 K were applied to the device while recording the I-V characteris-tics. From this, we had a deeper look on the current transport mechanism by obtaining the activation energy of the saturation current in the Arrhenius diagram. It is 1.3 eV, which can be related to the bandgap of MoS2 or WSe2 (both nominal 1.3 eV) as for traditional pn-junction diodes in bulk materials. Further-more, we applied a constant forward current to the device while measuring the voltage drop at different temperatures to investi-gate the temperature-sensor performance. In the range of 40 K up to 300 K, the sensitivity of the sensor is ~2 mV/K, which is comparable to Si devices, while the linearity is still lower (R2 ~ 0.94). On the other hand, the demonstrated device consists only of 2D materials and is, thus, substrate independent, ultra-thin, and can be fabricated on a fully flexible substrate in a low-cost process.

Nanomechanical resonators have become integral to technological advancements and scientific progress in modern society. Not only do they enable exquisite precision in sensing applications, but they also allow for exploring quantum mechanics and the development of quantum technologies. These applications require resonators with high quality factors capable of isolating them from environmental noise, specifically crucial at room temperature. The focus of this thesis is on investigating the limits of quality factors in nanomechanical resonators operating at room temperature. The study revolves around four main facets, addressing limitations in fabrication techniques, and design strategies, exploring the impact of aspect ratio on quality factor enhancement, and investigating the potential for temperature sensing. Firstly, we address the limits imposed by current fabrication techniques to realize high aspect ratio resonators, such as stiction and collapse due to interfacial forces like capillary. To overcome these challenges, we develop and characterize an SF6 plasma etching technique which enables a quick and controllable release of nanomechanical resonators. The high fidelity achieved through this approach allows the use of advanced optimization strategies to design resonators with exceptional quality factors. In doing so, we tackle the limits of design strategies, which have primarily relied on human intuition until now. By harnessing the power of Bayesian Optimization and inspired by nature, we discover a strategy to increase the quality factor at low order mode via a torsional soft-clamping mechanism. The experimental validation of the resulting spiderweb resonators confirms quality factors surpassing 1 billion at room temperature in the kHz frequency range. Notably, these resonators contain no features smaller than 1 micrometer, ensuring a fast and cost-effective fabrication. Expanding on these findings, the thesis explores the, Dynamics of Micro and Nano Systems

This thesis explores the application of Distributed Temperature Sensing (DTS) technology to observe temperature gradients and turbulent eddies within and above a forest vegetation layer. Atmospheric temperature gradients tie directly to heat transfer, a primary mode of which are turbulent eddies. The goal in studying these elements is to enhance the understanding of land-atmosphere coupling, which plays a role in climate and weather modelling. The data collection took place in the first two weeks of November 2022 at a meteorology study site in Loobos, the Veluwe. A fiber optic cable was installed, running from the forest floor to 1.5 times the canopy height along a tower. The DTS technology provided high-resolution temperature measurements at one-second intervals. Fluctuations in these profiles could potentially be associated with turbulent eddies. By analyzing temperature profiles over time and integrating meteorological data, the study provided insights into the temporal evolution of vertical temperature distribution at the test site and its sensitivity to weather conditions. Phenomena such as direct sunlight, rainfall, canopy effects, and inversion layers were identified in the DTS data and validated with other meteorological measurements. Notably, sharp temperature inversions observed on two nights exhibited strong correlations with wind speed and its variation. Increases in wind speed and variability were associated with lower inversion heights., Civil Engineering

Die additive Fertigung hat in den letzten Jahren großes Interesse geweckt, da sie einige Vorteile gegenüber herkömmlichen Fertigungsverfahren aufweist. Trotz des Potenzials sind viele Anwendungen aufgrund von Zuverlässigkeitsproblemen und einer begrenzten Materialauswahl immer noch auf das Rapid Prototyping beschränkt. Diese wissenschaftliche Studie zeigt zwei Anwendungen, die über das Rapid Prototyping hinausgehen und dabei strukturelle und funktionelle Materialien verwenden. Zuerst wird ein probabilistischer Prozess für den Leichtbau mit Gitterstrukturen vorgeschlagen. Zweitens wird eine Materialformulierung entwickelt, die das Anisotropie-Problem der Schmelzschichtung löst und Funktionsintegration durch elektrische Leitfähigkeit sowie Temperatur- und Dehnungsmessung ermöglicht., Additive manufacturing has attracted great interest in recent years as it shows several advantages over conventional manufacturing techniques. Despite its potential, many applications are still limited to rapid prototyping due to reliability issues and a limited material choice. This study shows two applications that go beyond rapid prototyping using structural and functional materials. First, a probabilistic process for lightweight design with lattice structures is proposed. Second, a new material formulation is developed that solves the anisotropy issue of fused filament fabrication and allows functional integration by electrical conductivity as well as temperature and strain sensing.

The article proposes the implementation of a prototype module for the control of access to higher education institutions, in this case the Politecnico Colombiano Jaime Isaza Cadavid Poblado sectional through the temperature sensing biosafety protocol, the tool allows temperature capture and taking of personal data for each user who enters the institution automatically given the current situation due to Covid-19. For the implementation, the software and hardware of existing technologies that are used to capture the temperature in an automated way are characterized, from this, the most appropriate technology for the implementation is selected, using open-source libraries, to modify the source code according to the punctual need. Similarly, a web application is developed to enter personal data and replace the physical forms with a digital database., El presente artículo plantea la implementación de un módulo prototipo para el control de acceso a instituciones de educación superior, en este caso el Politécnico Colombiano Jaime Isaza Cadavid. Sede Poblado, a través del protocolo de bioseguridad sensado de temperatura. Esta herramienta permite la captura automática de temperatura y toma de datos personales para cada usuario que ingresa a la institución dada la situación que se presenta actualmente por el covid-19. Parala implementación se caracteriza el software y hardware de tecnologías ya existentes que se utilizan para capturar la temperatura de manera automatizada, a partir de esto se selecciona la tecnología más adecuada para la implementación utilizando librerías open source para modificar el código fuente según la necesidad puntual. De igual forma, se desarrolla una aplicación web para el ingreso de datos personales que reemplacen las planillas físicas por una base de datos digital

High precision temperature measurements are a transversal need in a wide area of physical experiments. Space-borne gravitational wave detectors are a particularly challenging case, requiring both high precision and high stability in temperature measurement. In this contribution, we present a design able to reach 1 µK/Hz---v in most of the measuring band down to 1 mHz, and reaching 20 µK/Hz---v at 0.1 mHz. The scheme is based on resistive sensors in a Wheatstone bridge configuration which is AC modulated to minimize the 1/f noise. As a part of our study, we include the design of a test bench able to guarantee the high stability environment required for measurements. We show experimental results characterising both the test bench and the read-out, and discuss potential noise sources that may limit our measurement., Peer Reviewed, Postprint (published version)

Nickel manganite nanocrystalline fibers were obtained by electrospinning and subsequent calcination at 400 °C. As-spun fibers were characterized by TG/DTA, Scanning Electron Microscopy and FT-IR spectroscopy analysis. X-ray diffraction and FT-IR spectroscopy analysis confirmed the formation of nickel manganite with a cubic spinel structure, while N2 physisorption at 77 K enabled determination of the BET specific surface area as 25.3 m2/g and (BJH) mesopore volume as 21.5 m2/g. The material constant (B) of the nanocrystalline nickel manganite fibers applied by drop-casting on test interdigitated electrodes on alumina substrate, dried at room temperature, was determined as 4379 K in the 20–50 °C temperature range and a temperature sensitivity of −4.95%/K at room temperature (25 °C). The change of impedance with relative humidity was monitored at 25 and 50 °C for a relative humidity (RH) change of 40 to 90% in the 42 Hzπ1 MHz frequency range. At 100 Hz and 25 °C, the sensitivity of 327.36 ± 80.12 kΩ/%RH was determined, showing that nickel manganite obtained by electrospinning has potential as a multifunctional material for combined humidity and temperature sensing.

In this paper, we demonstrate that nitride-based R/G/B micro-LEDs allow temperature sensing through a forward voltage response on both temperature and display devices. In temperature sensing, micro-LEDs operate in current constant mode, exhibiting an excellent performance with a sensitivity of 2.6/2.7/2.2 mV/K for blue/green InGaN micro-LEDs and red AlGaInP micro-LED under an injection current density of 1 mA/cm2, which is about two times lower sensitivity than the sensitivity limit obtained from the Shockley ideal diode equation. It is speculated that the lower sensitivity originated from parasitic resistances. It is also found that the band gaps of ternary InGaN and quaternary AlGaInP obtained from temperature-dependent electroluminescence spectra of red micro-LED agrees with the calculated values by using the semiempirical Varshni relationship. The EL of micro-LEDs is characterized by narrow emission widths of 18-41 nm, leading to wide color gamut covering up to 170/97% of the DCI P3/BT 2020, which are the standard color space of ultrahigh definition television system. © 2021 American Chemical Society.

The next-generation sutures should provide in situ monitoring of wound condition such as temperature while reducing surgical site infection during wound closure. In this study, functionalized nanodiamond (FND) and reduced graphene oxide (rGO) into biodegradable polycaprolactone (PCL) are incorporated to develop a new multifunctional suture with such capabilities. Incorporation of FND and rGO into PCL enhances its tensile strength by about 43% and toughness by 35%. The sutures show temperature sensing capability in the range of 25–40 °C based on the shift in zero-splitting frequency of the nitrogen-vacancy (NV–) centers in FND via optically detected magnetic resonance, paving the way for potential detection of infection or excessive inflammation in healing wounds. The suture surface readily coats with antibiotics to reduce bacterial infection risk to the wounds. The new suture thus is promising in monitoring and supporting wound closure.

Polypropylene (PP) remains the primary material for hernia meshes due to its biocompatibility, physical strength and ease of fabrication. However, PP meshes are still subject to complications such as mesh movement and bacterial infection that ultimately lead to mesh failure. This study describes a two-step functionalization of a PP mesh through dopamine-mediated chloro(triphenylphosphine)gold(I)/nanodiamond coatings. The gold compound provided an intrinsic surface with antimicrobial activity to the coatings, whilst the overall improvement in hydrophilicity and roughness allows for efficient adsorption of antibiotics with an aim for eradicating bacteria in the surrounding tissue. The presence of a gold compound on the surface of the mesh enhanced its contrast property, which may provide a surgical application to determine the ease of monitoring the PP mesh location after implantation inside the body to detect possible tears. Photostable negatively charged nitrogen-vacancy centres within the nanodiamonds provides an exciting possibility to optically assess locally elevated temperatures often associated with infection or excessive inflammation. The biocompatibility, antibiotic loading and associated antimicrobial properties of the coated mesh were investigated to show the potential of this new coating for future applications in hernia surgical procedures.

Nanocrystalline nickel manganite (NiMn2O4) powder with a pure cubic spinel phase structure was synthesized via sol-gel combustion and characterized with XRD, FT-IR, XPS and SEM. The powder was mixed with sodium alginate gel to form a nano-biocomposite gel, dried at room temperature to form a thick film and characterized with FT-IR and SEM. DC resistance and AC impedance of sensor test structures obtained by drop casting the nano-biocomposite gel onto test interdigitated PdAg electrodes on an alumina substrate were measured in the temperature range of 20-50 degrees C at a constant relative humidity (RH) of 50% and at room temperature (25 degrees C) in the RH range of 40-90%. The material constant obtained from the measured decrease in resistance with temperature was determined to be 4523 K, while the temperature sensitivity at room temperature (25 degrees C) was -5.09%/K. Analysis of the complex impedance plots showed a dominant influence of grains. The decrease in complex impedance with increase in temperature confirmed the negative temperature coefficient effect. The grain resistance and grain relaxation frequency were determined using an equivalent circuit. The activation energy for conduction was determined as 0.45 eV from the temperature dependence of the grain resistance according to the small polaron hopping model, while the activation energy for relaxation was 0.43 eV determined from the Arrhenius dependence of the grain relaxation frequency on temperature.

Nickel manganite nanocrystalline fibers were obtained by electrospinning and subsequent calcination at 400 degrees C. As-spun fibers were characterized by TG/DTA, Scanning Electron Microscopy and FT-IR spectroscopy analysis. X-ray diffraction and FT-IR spectroscopy analysis confirmed the formation of nickel manganite with a cubic spinel structure, while N-2 physisorption at 77 K enabled determination of the BET specific surface area as 25.3 m(2)/g and (BJH) mesopore volume as 21.5 m(2)/g. The material constant (B) of the nanocrystalline nickel manganite fibers applied by drop-casting on test interdigitated electrodes on alumina substrate, dried at room temperature, was determined as 4379 K in the 20-50 degrees C temperature range and a temperature sensitivity of -4.95%/K at room temperature (25 degrees C). The change of impedance with relative humidity was monitored at 25 and 50 degrees C for a relative humidity (RH) change of 40 to 90% in the 42 Hz pi 1 MHz frequency range. At 100 Hz and 25 degrees C, the sensitivity of 327.36 +/- 80.12 k omega/%RH was determined, showing that nickel manganite obtained by electrospinning has potential as a multifunctional material for combined humidity and temperature sensing.

A 6.4 nW 1.7% relative inaccuracy (R-IA) CMOS sub-thermal drain voltage-based temperature sensor is proposed. The proposed stabilized sub-thermal drain voltage current generator achieves a highly linear PTAT output without nonlinearity fitting or post-fabrication trimming and increases the accuracy of the sensor. A combination of the current generator and a frequency-locked loop relaxes the tradeoff between power and temperature stability of the current-to-frequency converter and achieves supply voltage-independent operation. Measured results of the prototype fabricated in a 65-nm CMOS process show that the proposed temperature sensor has a -1.0/+0.7 °C inaccuracy (= R-IA of 1.7%) while achieving a resolution of 75 mK over a temperature range of -30 °C to 70 °C. The line sensitivity of the sensor is 2.8 °C/V., Electronic Instrumentation

When transporting perishable foods in the Cold Supply Chain (CSC), it is essential that they are maintained in a controlled temperature environment (typically from -1° to 10°C) to minimize spoilage. Fresh-food products, such as, meats, fruits, and vegetables, experience discoloration and loss of nutrients when exposed to high-temperatures. Also, medicines, such as, insulin and vaccines, can lose potency if they are not maintained at the appropriate temperatures. Consequently, the CSC is critical to the growth of global trade and to the worldwide availability of food and health supplies; especially, when considering that the retail food market consists mostly (approximately 65%) of fresh-food products. The current method of temperature monitoring in the CSC is limited to discrete location-based measurements. Subsequently, this data is used to assess the overall quality of transported goods. As a result, this method cannot capture all the common irregularities that can occur during the delivery cycle. Therefore, an effective sensor solution to monitor such items is necessary. Radio Frequency Identification (RFID) is a pragmatic wireless technology with a standardized communication protocol. Thus far, passive RFID temperature sensors have been investigated. However, each design has a limitation from which a set of design guidelines for an improved sensor solution is developed. That is, the new sensor should: (a) be compact to be applicable on individual products, (b) utilize purely passive technology to ensure longevity and cost-effectiveness, (c) monitor goods in a continuous fashion (e.g., operate through multiple room-to-cold and cold-to-room temperature cycles), and (d) operate in an independent mode, so that no resetting is required. In this research, antenna systems and RF circuit design techniques are combined with Liquid Crystal Elastomers (LCEs) to develop three novel temperature sensors. LCEs are temperature responsive polymers that are programmable and rever

This thesis describes the design of an ultra-low power temperature to digital converter. It is intended to monitor the excess heat produced during the wireless charging of implantable medical devices such as pacemakers. The TDC is designed to achieve an accuracy of ±0.1 °C (3 sigma) from 27 °C to 47 °C, and ±0.3 °C (3 sigma) from -40 °C to 85 °C after a 1-point trim. It also achieves a resolution of 0.01 °C at 10 Sa/s. The low power consumption (155 nW) is made possible by the implementation of a self-biasing BJT-core. Its low power consumption, accuracy, and resolution make it ideally suited for clinical temperature monitoring., Electrical Engineering | Microelectronics

The temperature evaluation through the measurement of emission intensities (intensity ratio method) require two distinct bands; one of which is used as a reference, and the emission intensity of other is monitored as a function of a change in temperature. Herein, we report the influence of excitation wavelengths, and a coupling scheme between lanthanoid and defect emission from the host lattice, to extend the temperature sensing range by using a single crystal of europium (III) phosphate. The temperature dependence of emission intensity was studied for different excitation wavelengths: 365 (intraconfigurational 4f2 excitation), 338 (defect excitation), and 254 nm (O2- →Eu3+ charge-transfer excitation), in the temperature range, 293--865 K. We determined the Boltzmann equilibrium among different coupling schemes using a linear regression model to infer that for an excitation at 338 nm wavelength, and evaluating the intensity ratio between defect emission and the Eu3+ 5D0,1 → 7FJ transitions, the temperature sensing range can be extended upto at least 865 K, with relative sensitivity in the range, 0.33-1.94%K-1 (at 750 K). The results showed resolution of < 1 K with an excellent reproducibility, suggesting that the thermometers can be used with high reliability.

Readily available temperature sensing in boilers is necessary to improve efficiencies, minimize downtime, and reduce toxic emissions for a power plant. The current techniques are typically deployed as a single-point measurement and are primarily used for detection and prevention of catastrophic events due to the harsh environment. In this work, a multi-point temperature sensor based on wavelength-multiplexed sapphire fiber Bragg gratings (SFBGs) were fabricated via the point-by-point method with a femtosecond laser. The sensor was packaged and calibrated in the lab, including thermally equilibrating at 1200 °C, followed by a 110-h, 1000 °C stability test. After laboratory testing, the sensor system was deployed in both a commercial coal-fired and a gas-fired boiler for 42 days and 48 days, respectively. The performance of the sensor was consistent during the entire test duration, over the course of which it measured temperatures up to 950 °C (with some excursions over 1000 °C), showing the survivability of the sensor in a field environment. The sensor has a demonstrated measurement range from room temperature to 1200 °C, but the maximum temperature limit is expected to be up to 1900 °C, based on previous work with other sapphire based temperature sensors.

[EN] We report the development of a temperature sensing probe created as a result of the combination of an optical fiber and a porous silicon microcavity (PSMC). After determining the physical parameters of the PSMC to achieve the required porous sensing structure, it was fabricated by electrochemically etching a silicon wafer. A 1-mm(2) PSMC piece was attached to the tip of an optical fiber so that temperature variations can be monitored in real-time exactly on that point. First, the performance of the PSMC sensor probe was characterized in a stable environment as water, obtaining a sensitivity around 110 pm/degrees C and a resolution in the 10-4 degrees C range. Afterward, the temperature transmission dynamics in air environment were studied.

Many organisms need to respond to complex, noisy environmental signals for developmental decision making. Here, we dissect how Arabidopsis plants integrate widely fluctuating field temperatures over month-long timescales to progressively upregulate VERNALIZATION INSENSITIVE3 (VIN3) and silence FLOWERING LOCUS C (FLC), aligning flowering with spring. We develop a mathematical model for vernalization that operates on multiple timescales-long term (month), short term (day), and current (hour)-and is constrained by experimental data. Our analysis demonstrates that temperature sensing is not localized to specific nodes within the FLC network. Instead, temperature sensing is broadly distributed, with each thermosensory process responding to specific features of the plants' history of exposure to warm and cold. The model accurately predicts FLC silencing in new field data, allowing us to forecast FLC expression in changing climates. We suggest that distributed thermosensing may be a general property of thermoresponsive regulatory networks in complex natural environments.

Flexible electronics have become the subject of industry focus, generating a market desire for fully flexible temperature sensors. To the best of our knowledge, there are no current systems that can adequately satisfy both the mechanical flexibility and sensing performance demanded for commercial applications. This work focused on a design for a flexible temperature sensor by designing a thermistor using functional granular composites using ceramic NTC fibre particles and a resistive polymer matrix. The objective was to achieve good thermistor performance (high sensitivity: B-value > 3000 K, and low resistivity: rho ˜ 10^1 - 10^2 Ocm) while being mechanically flexible (surviving bending radii = 1 cm over 100 cycles). To achieve this objective this thesis work was organised into 5 major phases. Due to the high commercial value of NTC ceramic thermistors, no reference composition with its exact processing conditions are available in literature that produce a thermistor with commercially desirable properties. Phase 1 was therefore to select a NTC ceramic composition and Phase 2 was to investigate the necessary processing conditions to be able to produce bulk ceramics with adequate temperature sensing performance. Phase 3 involved making NTC ceramic fibres by wet fibre spinning and modifying the processing conditions developed in Phase 2. Phase 4 involved the selection of an appropriate polymer matrix and to attempt to create thermistor composites. Phase 5 involved creating more optimal composite thermistors using stencil printing and to test its thermistor and bending performance. Using an isotropic mixture of Mn2.4 Ni0.5 Cu0.1 O4 NTC ceramic fibre particles in an Electrodag matrix, composite thermistors were created by stencil printing onto thin-film substrates of polyethylene terephthalate that have silver inkjet printed interdigitate electrodes. A percolated network is formed with as little as 10 wt% of fibres (˜ 2.86 vol%). The composite with 10 wt% of fibres ha, Aerospace Engineering

We propose an efficient model-based signal processing approach for optical fiber sensing with fiber Bragg grating (FBG) arrays. A position estimation based on an estimation of distribution algorithm (EDA) and a reflectivity estimation method using a parametric transfer matrix model (TMM) are outlined in detail. The estimation algorithms are evaluated with Monte Carlo simulations and measurement data from an incoherent optical frequency domain reflectometer (iOFDR). The model-based approach outperforms conventional Fourier transform processing, especially near the spatial resolution limit, saving electrical bandwidth and measurement time. The models provide great flexibility and can be easily expanded in complexity to meet different topologies and to include prior knowledge of the sensors. Systematic errors due to crosstalk between gratings caused by multiple reflections and spectral shadowing could be further considered with the TMM to improve the performance of large-scale FBG array sensor systems.

High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm/s. By this, a better control of high-pressure microfluidic platforms has been achieved., Part financed through Swedish Agency for the Innovation System, Vinnova, through the Centre for Natural Disaster Science (CNDS)

This synthesis project is focused on implementing an Internet of Things (IoT) network to measure environmental data in the city of Delft. This network consists of sensor platforms that are placed in the urban environment. Each sensor platform is mounted on fixed locations and it is not moved during the measurement time. The aim is to raise community’s environmental awareness to improve the quality of the environment. Recent developments in technology made it possible to fabricate small, efficient, and reliable sensors boards which are the base of these sensors platforms and making them efficient and reliable. Sensor boards like Arduino, Raspberry Pi, and LoPy are some examples of these small sensor boards. In this project, the LoPy is used which is a sensor board that is equipped with Bluetooth Low Energy, Wifi and a LoRa radio. This last one is a communication technology that makes longer communication distances possible. The sensor network measures four different environmental indicators that will be distributed to the public: temperature, humidity, noise and air quality. The network then communicates via LoRa this data to one centralized server where the data is stored, processed and sent back to the citizens. This data is made publicly accessible to academia, citizens and the stakeholders alike. The network is also made interactive, people who pass by can interact with the sensors and request specific environmental data in real time. The sensor network has been build and deployed in the city. During the uptime of the network it succeeded to provide the data to the citizens via the feedback mechanisms: a website with a dashboard and an automated twitter account. Local differences have been measured with temperature and humidity sensors. With regard to the noise sensor and air quality sensors no definitive conclusions could be drawn., Sensor City Delft - Geomatics Synthesis Project on IoT, Geomatics

Along with the rise of the smart city movement, Internet of Things is an upcoming phenomenon. Objects and devices are becoming more and more wirelessly interconnected, communicating information between themselves and to human beings. As an extension on static sensor networks that gather real-time environmental data, the feasibility of implementing a dynamic sensor network based on LoRa communication is researched. To achieve such a dynamic system, a self-developed sensor platform was constructed, based on the microcontroller LoPy. Sensors attached to it include a hygrometer, thermometer and microphone. The emphasis of the research was on localisation of the sensors, to put the gathered sensor data into geographical context. A WiFi fingerprinting radiomap was constructed based on available MAC-addresses, their signal strengths, and GPS coordinates. The GPS module was only used for composing the radiomap. When the radiomap is completed, the module can be switched off, only to be switched on for periodical updates of the radiomap. The quality of the radiomap methodology was evaluated by constructing it of measurements gathered in four days, and testing it for the remaining three days. This test gave a correctness of 50% while another 38% of measurements were localised in a neighbouring cell. The correctness can be improved by having a longer training period. The quality of the collected sensor data turned out to be dependent on the weather conditions and the placement location on the carrier vehicle. Vehicle requirements were specified as driving through the city centre and having a schedule and route producing as little noise, heat and air pollution as possible. Another topic of research was LoRa communication, which was deemed as very limited for dynamic implementations, as the sending of location-related data takes up a large part of the already limited message size. To decrypt the sent message and store it in a meaningful database, Node-RED was used. De, Geomatics

[EN] Fiber grating sensors and devices have demonstrated outstanding capabilities in both telecommunications and sensing areas, due to their well-known advantageous characteristics. Therefore, one of the most important motivations lies in the potential of customized fiber gratings to be suitably employed for improving the interrogation process of optical fiber sensors and systems. This Ph.D. dissertation is focused on the study, design, fabrication and performance evaluation of customized fiber Bragg gratings (FBGs) and long period gratings (LPGs) with the double aim to present novel sensing technologies and to enhance the response of existing sensing systems. In this context, a technique based on time-frequency domain analysis has been studied and applied to interrogate different kind of FBGs-based sensors. The distribution of the central wavelength along the sensing structures has been demonstrated, based on a combination of frequency scanning of the interrogating optical pulse and optical time-domain reflectometry (OTDR), allowing the detection of spot events with good performance in terms of measurand resolution. Moreover, different customized FBGs have been interrogated using a technology inspired on the operation principle of microwave photonics (MWP) filters, enabling the detection of spot events using radio-frequency (RF) devices with modest bandwidth. The sensing capability of these technological platforms has been fruitfully employed for implementing a large scale quasi-distributed sensor, based on an array of cascaded FBGs. The potentiality of LPGs as fiber optic sensors has also been investigated in a new fashion, exploiting the potentials of MWP filtering techniques. Besides, a novel approach for simultaneous measurements based on a half-coated LPG has been proposed and demonstrated. Finally, the feasibility of FBGs as selective wavelength filters has been exploited in sensing applications; an alternative approach to improve the response and performance, [ES] Los sensores y dispositivos en fibra basados en redes de difracción han mostrado excepcionales capacidades en el ámbito de las telecomunicaciones y del sensado, gracias a sus excelentes propiedades. Entre las motivaciones más estimulantes destaca la posibilidad de fabricar redes de difracción ad-hoc para implementar y/o mejorar las prestaciones de los sensores fotónicos. Esta tesis doctoral se ha enfocado en el estudio, diseño, fabricación y evaluación de las prestaciones de redes de difracción de Bragg (FBGs) y de redes de difracción de periodo largo (LPGs) personalizadas con el fin de desarrollar nuevas plataformas de detección y a la vez mejorar la respuesta y las prestaciones de los sensores fotónicos ya existentes. En este contexto, una técnica basada en el análisis tiempofrecuencia se ha estudiado e implementado para la interrogación de sensores en fibra basados en varios tipos y modelos de FBGs. Se ha analizado la distribución de la longitud de onda central a lo largo de la estructura de sensado, gracias a una metodología que conlleva el escaneo en frecuencia del pulso óptico incidente y la técnica conocida como reflectometria óptica en el dominio del tiempo (OTDR). De esta manera se ha llevado a cabo la detección de eventos puntuales, alcanzando muy buenas prestaciones en términos de resolución de la magnitud a medir. Además, se han interrogado varias FBGs a través de una técnica basada en el principio de operación de los filtros de fotónica de microondas (MWP), logrando así la detección de eventos puntuales usando dispositivos de radio-frecuencia (RF) caracterizados por un moderado ancho de banda. La capacidad de sensado de estas plataformas tecnológicas ha sido aprovechada para la realización de un sensor quasi-distribuido de gran alcance, formado por una estructura en cascada de muchas FBGs. Por otro lado, se han puesto a prueba las capacidades de las LPGs como sensores ópticos según un enfoque novedoso; para ello se han aprovechados las potencialida, [CA] Els sensors i dispositius en fibra basats en xarxes de difracció han mostrat excepcionals capacitats en l'àmbit de les telecomunicacions i del sensat, gràcies a les seus excel¿lents propietats. Entre les motivacions més estimulants destaca la possibilitat de fabricar xarxes de difracció ad-hoc per a implementar i/o millorar les prestacions de sensors fotònics. Esta tesi doctoral s'ha enfocat en l'estudi, disseny, fabricació i avaluació de les prestacions de xarxes de difracció de Bragg (FBGs) i de xarxes de difracció de període llarg (LPGs) personalitzades per tal de desenvolupar noves plataformes de detecció i al mateix temps millorar la resposta i les prestacions dels sensors fotònics ja existents. En este context, una tècnica basada en l'anàlisi temps-freqüència s'ha estudiat i implementat per a la interrogació de sensors en fibra basats en diversos tipus i models de FBGs. S'ha analitzat la distribució de la longitud d'ona central al llarg de l'estructura de sensat, gràcies a una metodologia que comporta l'escaneig en freqüència del pols òptic incident i la tècnica coneguda com reflectometria òptica en el domini del temps (OTDR). D'esta manera s'ha dut a terme la detecció d'esdeveniments puntuals, aconseguint molt bones prestacions en termes de resolució de la magnitud a mesurar. A més, s'han interrogat diverses FBGs a través d'una tècnica basada en el principi d'operació dels filtres de fotònica de microones (MWP), aconseguint així la detecció d'esdeveniments puntuals utilitzant dispositius de ràdio-freqüència (RF) caracteritzats per un moderat ample de banda. La capacitat de sensat d'aquestes plataformes tecnològiques ha sigut aprofitada per a la realització d'un sensor quasi-distribuït a llarga escala, format per una estructura en cascada de moltes FBGs. D'altra banda, s'han posat a prova les capacitats de les LPGs com a sensors òptics segons un enfocament nou; per a això s'han aprofitat les potencialitats dels filtres de MWP. Així mateix, s'ha estudiat i

Deze thesis beschrijft de ontwerpkeuzes, het ontwerp en het begin van de implementatie van een sensorsysteem dat voor e12,50 aan componenten de waterdiepte, temperatuur en conductiviteit meet in waterputten. Aan de hand van de temperatuur en de conductiviteit kan de zoutconcentratie benaderd worden. Er is gekozen voor een combinatie van nieuwe sensoren en kant en klare sensoren. Het systeem gebruikt een contactloze capacitievemtussen de 100 kHz sinus aan de ingang en de stroom aan de uitgang wordt de conductiviteit bepaald. Een digitale sensor voor de temperatuur en een drukmeting voor de diepte completeren het systeem. Het systeem verwerkt de gemeten waarden zodat deze digitaal gemaakt kunnen worden met gangbare ADC’s. Uiteindelijk wordt er een definitief circuit besproken en zijn er voor de geleiding en temperatuur eerste resultaten van het prototype te zien. Er is geconcludeerd dat de temperatuursensor toereikend is en dat de geleidingssensor functioneert van 0 - 750 ¹S/cm. Met verder onderzoek kan dit uitgebreid worden tot een groter bereik. Voor de dieptemeting is aangeraden een druksensor te gebruiken., Electrical Engineering, Mathematics and Computer Science, Microelectronics, Electrical Engineering

Fibre optic Distributed Temperature Sensing (DTS) is widely applied in earth sciences. Many applications require a spatial resolution higher than the provided by the DTS instrument. Measurements at these higher resolutions can be achieved with a fibre optic cable helically wrapped on a cylinder. The effect of the probe construction, such as its material, shape, and diameter, on the performance has been poorly understood. In this article, we study datasets obtained from a laboratory experiment using different cable and construction diameters, and three field experiments using different construction characteristics. This study shows that the construction material, shape, diameter, and cable attachment method can have a significant influence on DTS temperature measurements. We present a qualitative and quantitative approximation of errors introduced through the choice of auxiliary construction, influence of solar radiation, coil diameter, and cable attachment method. Our results provide insight into factors that influence DTS measurements, and we present a number of solutions to minimize these errors. These practical considerations allow designers of future DTS measurement setups to improve their environmental temperature measurements., Water Management, Civil Engineering and Geosciences

A luminescent lanthanide metal-organic framework (MOF) based on Eu and Tb ions with 2-phenylsuccinate (EuTb-psa) was obtained solvothermally to explore its behavior as a temperature sensor in an unconventional temperature range through the study of the thermal evolution of the hypersensitive 4f-4f D→F transition and the luminescence lifetime. The efficiency of the luminescence process was evaluated through the europium intrinsic quantum yield (Q), and its variation as a function of temperature is also reported. The optical properties of four isostructural compounds (Pr-psa, Nd-psa, Gd-psa, and Tb-psa) were investigated and compared with those of related compounds. The energy of the triplet state of the ligand was also estimated. The samples were fully characterized by single-crystal and powder X-ray diffraction, thermal analysis, and vibrational spectroscopy. The heterogeneous catalytic activities of a series of Ln-psa MOFs (with Ln = Sm, Eu, Gd, Tb, EuGd, and EuTb) were evaluated in a one-pot cyanosilylation with benzaldehyde as the substrate. A luminescent lanthanide metal-organic framework (MOF) based on Eu and Tb ions with 2-phenylsuccinate (EuTb-psa) is explored as a temperature sensor. The optical properties of four isostructural compounds (Pr-psa, Nd-psa, Gd-psa, and Tb-psa) are also investigated. The heterogeneous catalytic activities of these Ln-psa MOFs are evaluated in a one-pot cyanosilylation reaction.

Temperature-sensitive transient receptor potential (TRP) ion channels are members of the large tetrameric cation channels superfamily but are considered to be uniquely sensitive to heat, which has been presumed to be due to the existence of an unidentified temperature-sensing domain. Here we report that the homologous voltage-gated potassium (Kv) channels also exhibit high temperature sensitivity comparable to that of TRPV1, which is detectable under specific conditions when the voltage sensor is functionally decoupled from the activation gate through either intrinsic mechanisms or mutations. Interestingly, mutations could tune Shaker channel to be either heat-activated or heat-deactivated. Therefore, high temperature sensitivity is intrinsic to both TRP and Kv channels. Our findings suggest important physiological roles of heat-induced variation in Kv channel activities. Mechanistically our findings indicate that temperature-sensing TRP channels may not contain a specialized heat-sensor domain; instead, non-obligatory allosteric gating permits the intrinsic heat sensitivity to drive channel activation, allowing temperature-sensitive TRP channels to function as polymodal nociceptors.

The advancement of renewable energy technologies is critical due to the unsustainable nature of currently used energy sources and the need to meet increasing energy demands. A broad and diverse energy plan is important for long term energy independence and stability. Geothermal energy sources including hydrothermal systems and enhanced geothermal systems (EGS) should play a key role in this energy plan. Geothermal energy is the most reliable, currently developed, schedulable alternative energy source. It is estimated that improvements in these systems have the potential to provide at least 200,000 exajoules of energy to the U.S. in as little as 50 years [1]. The progress in developing this field is challenging in part due to the complex geochemical and geophysical properties of the subsurface environment. This dissertation reviews geothermal energy system limitations due to current well monitoring technologies and introduces microelectromechanical systems (MEMS) sensors as a means of optimizing well performance. Harsh environment MEMS offer an ideal alternative to macro-scale sensors due to their harsh environment material compatibility, the ability to couple MEMS with wireless RF transmission systems, and their small footprint.In this work, harsh environment MEMS encapsulation materials are tested in simulated geothermal environments to determine their survivability. The sensors must be encapsulated to provide protection from oxidation, erosion, surface roughening, and other chemical attacks. Encapsulation materials such as silicon carbide, sapphire, vitreous carbon, and poly-crystalline diamond were tested in multiple simulated geothermal environments to determine a suitable protective layer for these MEMS devices. Once appropriate materials are determined, two temperature sensors are designed, optimized, fabricated, and tested. The first sensor improves upon existing out-of-plane MEMS capacitive temperature sensor devices by utilizing harsh environment materials.

Lithium-indium oxide is a high-density (5.9 g center dot cm(-3)), wide band-gap semiconductor with promising applications for scintillating detection of solar neutrinos as well as for efficient phosphorescence when doped with Er3+ or Sm3+ ions. In this report, we demonstrate visible upconversion emission of Er3+-doped LiInO2 synthesized by a simple solid-state chemistry procedure and discuss mechanisms responsible for pumping the Er3+ ions to upper levels. Intense upconversion emission is observed in the green and red spectral regions under near-infrared excitation, and it is greatly enhanced by co-doping with Yb3+ ions. We also examined the upconversion intensity change as a function of temperature, and, consequently, possible applications of this material as a low-temperature sensor.

Animals possess systems for sensing environmental temperature using temperature-sensitive ion channels called transient receptor potential channels (TRPs). Various TRPs have been identified and characterized in mammals. However, those of ectotherms, such as reptiles, are less well studied. Here, we identify the V subfamily of TRP (TRPV) in two reptile species: Japanese grass lizard (Takydromus tachydromoides) and Japanese four-lined ratsnake (Elaphe quadrivirgata). Phylogenetic analysis of TRPVs indicated that ectothermic reptilian TRPVs are more similar to those of endothermic chicken and mammals, than to other ectotherms, such as frog and fish. Expression analysis of TRPV4 mRNA in the lizard showed that its expression in tissues and organs is specifically controlled in cold environments and hibernation. The mRNA was ubiquitously expressed in seven tissues/organs examined. Both cold-treatment and hibernation lowered TRPV4 expression, but in a tissue/organ-specific manner. Cold-treatment reduced TRPV4 expression in tongue and muscle, while in hibernation it was reduced more widely in brain, tongue, heart, lung, and muscle. Interestingly, however, levels of TRPV4 mRNA in the skin remained unaffected after entering hibernation and cold-treatment, implying that TRPV4 in the skin may act as an environmental temperature sensor throughout the reptilian life cycle, including hibernation. This is the first report, to our knowledge, to describe reptilian TRPV4 in relation to hibernation.

Lithium-indium oxide is a high-density (5.9 g center dot cm(-3)), wide band-gap semiconductor with promising applications for scintillating detection of solar neutrinos as well as for efficient phosphorescence when doped with Er3+ or Sm3+ ions. In this report, we demonstrate visible upconversion emission of Er3+-doped LiInO2 synthesized by a simple solid-state chemistry procedure and discuss mechanisms responsible for pumping the Er3+ ions to upper levels. Intense upconversion emission is observed in the green and red spectral regions under near-infrared excitation, and it is greatly enhanced by co-doping with Yb3+ ions. We also examined the upconversion intensity change as a function of temperature, and, consequently, possible applications of this material as a low-temperature sensor.

Polymer coated ceramic cantilevers are highly sensitive to temperature changes, due to the large difference in coefficient of thermal expansion of the two materials. Silicon rich nitride (SRN) cantilevers coated with SU-8 for temperature sensing were fabricated and tested. The devices were coated with SU-8 through spin coating before they were released to obtain bimorph cantilevers. Deflection versus temperature measurements were carried out in ambient and nitrogen atmosphere. In ambient atmosphere, two different effects were observed as the temperature was cycled between 20 and 50°C; (i) shrinkage of SU-8 with increasing temperature, due to evaporation of absorbed moisture and (ii) thermal expansion of SRN and SU-8. Separately, these two effects generate bending in opposite direction. The observed overall bending was seen to be a combination of both. In nitrogen atmosphere, the cantilevers showed a unidirectional deflection versus temperature characteristic. Transverse bending of the cantilevers resulted in an increased rigidity of the cantilevers which could explain the ∼50% lower temperature response compared to the theoretical values.

Chemical sensing, imaging and microscopy based on the use of fluorescent probes has so far been limited almost exclusively to the detection of a single parameter at a time. We present a scheme that can overcome this limitation by enabling optical sensing of two parameter simultaneously and even at identical excitation and emission wavelengths of two probes provided (a) their decay times are different enough to enable two time windows to be recorded, and (b) the emission of the shorter-lived probe decays to below the detectable limit while that of the other still can be measured. We refer to this new scheme as the dual lifetime determination (DLD) method and show that it can be widely varied by appropriate choice of probes and experimental settings. DLD is demonstrated to work by sensing oxygen and temperature independently from each other by making use of two probes, one for oxygen (a platinum porphyrin dissolved in polystyrene), and one for temperature [a europium complex dissolved in poly(vinyl methylketone)]. DLD was applied to monitor the consumption of oxygen in the glucose oxidase-catalyzed oxidation of glucose at varying temperatures. The scheme is expected to have further applications in cellular assays and biophysical imaging. © 2008 Springer-Verlag.

A system for sensing water temperature includes a tow cable with an exterior surface having at least one helical groove formed therein and a metal tube lying in each helical groove. At least one optical temperature sensing element is provided in each metal tube. A thermally-conducting material fills each metal tube and surrounds each optical temperature sensing element contained therein. An outer jacket layer is formed over the tow cable and metal tube.

A collection of state-of-the-art papers on products from the Defense Meteorological Satellite Program (DMSP) sensors, particularly the SSM/T and SSM/I products are presented. Partial contents include: SM/I: Status Report; Calibration/Validation of the DMSP Microwave Water Vapor Sounder (SSM/T-2); Performance of DMSP Special Sensor Microwave Humidity Profiler (SSM/T-2) Preliminary Results; DMSP Block 6: A Data Driven Approach; NOAA/NESDIS: operational SSM/T Products and Distribution; NOAA/NESDIS SSM/T Algorithms and Evaluation; Defense Meteorological Satellite Program Microwave Radiometer Processing at Air Force Global Weather Central; DMSP Special Sensor Microwave/Imager Processing at the Fleet Numerical Oceanography Center: Operational Status, Application and Plans; An Overview of the Experimental SSM/I Orbit-by- Orbit Products System (SSMIPROD) at NOAA/NESDIS; SSM/I Mapped Experimental Environmental Image Products; SSM/I Total Precipitable Water Vapor Algorithms: A Reprise and Update; The Use of the DMSP SSM/I for the Generation of Precipitation Products at NOAA/NESDIS: Part 1: A Status Report; The Use of the DMSP SSM/I for the Generation of Precipitation Products at NOAA/NESDIS: Part 2: Scientific Results; Production and Evaluation of Experimental SSM/I Ice and Wind Products at NOAA/NESDIS; Real Time Quality Control of SSM/I Wind Speed Data; Status of NESDIS Distribution of SSM/I Products; Processing and Distributing SSM/I Data via the Wet Net Project.

Rapid industrialisation in the last few centuries has led to a significant increase in land temperatures due to the increase in atmospheric concentrations of greenhouse gases. This warming effect increases the frequency of extreme temperature events leading to a higher probability of heat waves, which threaten agricultural output and food security. It is important to study the effects of heat stress on crop productivity, and for that we need a strong understanding of how plants react to elevated temperatures. Currently, we have decades worth of literature on the effects of heat on photosynthesis and reproduction in plants, yet a major component of heat response is still relatively unknown. The root system, aptly known as the ‘hidden half’ of the plant has been shown to sense and react to elevated temperatures but the exact molecular mechanisms of stress response in the root present themselves as a gap in our current understanding. Recent literature suggests that the root system may be more susceptible to higher temperatures than the shoot, and this makes it crucial to understand the effects of high temperature on roots. In this literature review, we discuss the predictions and simulations that point towards a warmer future and what this means for our agricultural system. We explore temperature sensing in roots, an important process, yet the mechanisms of which are still debated. Biochemical and molecular mechanisms of heat response are discussed with a special focus on how the root system has been shown to react to heat stress. Natural variation and genetic improvements in plant heat tolerance, both of which are important tools towards breeding more heat resilient crops, are also considered. This thesis aims to help us better understand the heat stress responses in roots, so that it may aid in breeding more climate proof crops.

The primary focus of this research was the integration of series-loaded resonant (SLR) converters into a field-programmable gate array controlled power converter for use in balancing a series-connected battery bank. As the limits of the power grid are continually extended, the market demand for alternate power sources and energy storage systems will continue to grow. The goal of this research was to build and integrate a bank of SLR converters for use in balancing a series-connected battery bank that is part of a broader system used for power storage and conversion. Voltage and temperature sensors were used to monitor individual cell state-of-charge and rate-of-charge and discharge. Voltage-to-frequency conversion was used to read sensor parameters. A battery balancing algorithm was designed, integrated and demonstrated with experimental results., http://archive.org/details/integrationndcon1094538989, Lieutenant, United States Navy, Approved for public release; distribution is unlimited.