Tesis sobre el tema "Temperature and RH sensors"
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Taguett, Amine. "Synthèse et étude thermodynamique d’alliages Ir-Rh à l’état massif et en films minces pour la réalisation de capteurs SAW fonctionnant à haute température (700°C-1000°C) dans l’air". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAA016/document.
Texto completoThe surface acoustic waves (SAW) technology was invented approximately fifty years ago. This technology is currently widely used in the telecommunication industry to make, among others, GHz-range filters. Another very active development axis for the SAW technology is related to the achievement of micro sensors (to measure temperatures, pressures, deformations, concentrations of chemical or biological species) for industrial sectors with strong constraints such as aerospace, automotive, metallurgy, or medical sectors. Their high sensitivity to environmental conditions, their small size and the possibility to interrogate them remotely without adding any embedded electronics (passive sensors), provides SAW sensors a high innovation potential, in particular for applications taking place in hostile environments. SAW devices are constituted by a piezoelectric substrate on which are patterned electrodes from a conductive film. These electrodes are typically 100 nm-thick and are called, because of their shape, interdigital transducers (IDT). Our work was mainly focused on the choice of materials for the realization of IDTs to be used at very high temperatures, in air, for weeks periods, the current state-of-the-art operating temperature being close to 850 °C. Achieving high temperature IDTs requires finding a conductive material, physically and chemically stable under oxidizing conditions up to 1000°C, which retains its properties when grown as a thin layer. A recent study has highlighted the relevance of bulk Ir-Rh binary alloys for applications closely related to the targeted ones. The objective of this project is to transfer the properties of bulk Ir-Rh alloys to Ir-Rh thin layers, by collecting new thermodynamic data for the Ir-Rh binary system. Despite the difficulties of thermal analyses which were conducted up to 2300 °C, we have been able to carry out the first experimental measurements of solid-liquid temperatures equilibria (solidus and liquidus) of some Ir-Rh alloys. An important part of the work was afterwards devoted to the realization of Ir-Rh thin films deposition campaigns to optimize the key parameters and obtain films having the relevant stoichiometry and microstructure. Finally, the performance of SAW devices, made from optimized thin films, was evaluated. Very promising results were obtained: after a stabilization phase in the early hours of annealing, the SAW signal was unchanged throughout a 2 months period at 800 °C in air atmosphere
Hout, S. R. in't. "High-temperature silicon sensors". Delft, the Netherlands : Delft University Press, 1996. http://books.google.com/books?id=dApTAAAAMAAJ.
Texto completoHashmi, А. y А. Kalashnikov. "Comparison of the responsiveness of ultrasonic oscillating temperature sensors (UOTSes) and conventional sensors to temperature inflection". Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/55751.
Texto completoYerochin, S. Yu, A. N. Demenskiy, V. A. Krasnov y S. V. Shutov. "Diode temperature sensors with tunable sensitivity". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45971.
Texto completoSelli, Raman Kumar. "Fibre optic temperature sensors using fluorescent phenomena". Thesis, City University London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236641.
Texto completoBanim, Robert Seamus. "Improved temperature sensors for the process industry". Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245572.
Texto completoBirley, Joseph Leonard Mark. "An investigation of temperature controlled humidity sensors". Thesis, De Montfort University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393232.
Texto completoCederlund, Jacob. "Radiated Susceptibility Measurements on Analogue Temperature Sensors". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279959.
Texto completoAnvändningen av elektronik ökar i samhället och därför även nödvändigheten för testning av elektromagnetisk kompatibilitet. Ett vanligt problem inom elektromagnetisk kompatibilitet är att analoga sensorer lätt blir utstörda av elektromagnetiska fält. Hur man ska testa en elektronisk produkts känslighet mot elektromagnetiska fält styrs av standarder som ser till att resultaten av testerna går att återskapa. I detta examensarbete har analoga temperatursensorer skärmats med ett par vanliga metoder. Sensorernas känslighet har analyserats genom att undersöka hur deras utspänning påverkas när sensorn blir utsatt för elektromagnetiska fält med olika fältstyrkor. Sensorernas utspänning lästes av en Arduino som skärmades och testades för att se till all att den inte påverkades av de elektromagnetiska fälten som användes under testandet av sensorerna. Resultaten från de första sensortesterna visar att använda skärmade kablar till de analoga temeperatursensorerna och att filtrera bort störningar med ferriter sänkte sensorernas känslighet mot elektromagnetiska fält betydligt medan tvinnade kablar och RC filter inte gjorde det. Testerna visade också att jord- plan i detta fall ökade sensorernas känslighet då de inte erbjöd en bättre väg för strömmen att gå utan endast skapade en längre oavsiktlig antenn, vilket gjorde att den lättare kunde koppla till det elektromagnetiska fältet. Däremot visade det sig i en andra testomgång, att resultaten inte gick att återskapa ex- akt. Detta ifrågasätter hur tillförlitliga dessa standardiserade tester är och visar att man bör ha en ganska bred marginal när man designar för att minska en produkts känslighet mot elektromagnetiska fält, så att den på ett tillförlitligt sätt kommer kunna klara av känslighetstester.
Rashidi, Mohammadi Abdolreza. "MEMS pressure, temperature and conductivity sensors for high temperature and harsh environments". Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33783.
Texto completoSpirig, John Vincent. "A new generation of high temperature oxygen sensors". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1188570727.
Texto completoZhao, Weizhong. "Optical fibre high temperature sensors and their applications". Thesis, City University London, 2011. http://openaccess.city.ac.uk/1190/.
Texto completoHäggmark, Ilian. "Fiber Bragg Gratings in Temperature and Strain Sensors". Thesis, KTH, Tillämpad fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145741.
Texto completoKUNGLIGA TEKNISKA HOGSKOLAN Sammanfattning Laserfysikgruppen Institutionen for Tillampad Fysik SA104X Examensarbete inom Teknisk Fysik, Grundniva Fiberbraggitter i Temperatur- och Spanningssensorer av Ilian Haggmark Handledare: Michael Fokine Ett berbraggitter (FBG) ar en periodisk variation av brytningsindex i en optisk ber. FBG fungerar som ett vaglangdsselektivt lter och har era olika tillampningar inom bland annat telekomunikation och sensorerteknik. Fibersensorer bygger pa en enkel princip; bern paverkas av temperatur, spanning m.m. och da forandras ltreringen av vaglangder i FBG. Med en optisk spektrumanalysator kan forandringar i vaglangd registreras och konverteras till den storhet som mats. In detta examensarbete testas de egenskaper hos FBG som utnyttjas i temperatur- och spanningssensorer. Experiment for att forbattra precisionen hos sensorerna genom att gjuta in FBG i metall utfors ocksa.
Jones, Alexander R. "The application of temperature sensors into fabric substrates". Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/11991.
Texto completoDepartment of Apparel, Textiles, and Interior Design
Diana Sindicich
With continuing advancements in the area of electronics, there are more ways in which they are utilized in order to improve the lives of humans. These advancements have to led to the incorporation of electronic components into fabric structures, creating electronic textiles (e-textiles). As it has become possible to place small electrical components within clothing without the performance of the electronics being hampered, research has been conducted in the use of e-textiles in measuring aspects of the human body, such as the heart rate and perspiration rate. In the area of skin temperature, research has been conducted in the past using e-textiles for skin temperature measurement, but past efforts have been unsuccessful in incorporating useable temperature sensors into a fabric substrate. This study compared three types of sensors incorporated into woven and knitted fabrics, using insulated thermocouples, un-insulated thermocouples, and resistance temperature directors (RTDs). Three incorporation methods (weaving, interlacing into knit, and stitching) were used in six fabric samples, with the three sensor types woven and stitched into three woven fabric samples, while the sensors were interlaced into knitted fabric and stitched into the three knitted samples. Fabric hand washing and temperature measurement tests were conducted, and the temperature readings were analyzed statistically for comparison. The analysis conducted showed that the thermocouples that were interlaced or stitched onto the knitted fabric samples were best for temperature measurement due to their accuracy and durability, while the RTDs were unusable as a temperature sensor, as the removal of the electrical connectors during washing eliminated the calibration that was established before washing. This research was supported in part by the Institute for Environmental Research at Kansas State University.
Hadeler, Oliver. "Distributed feedback fibre laser strain and temperature sensors". Thesis, University of Southampton, 2002. https://eprints.soton.ac.uk/46100/.
Texto completoXu, Juncheng. "High Temperature High Bandwidth Fiber Optic Pressure Sensors". Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/25988.
Texto completoPh. D.
Jin, Sheng. "Silicon carbide pressure sensors for high temperature applications". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1296096110.
Texto completoAlmutairi, Fajhan Hilal Hamad. "Fibre optic distributed temperature sensors applications and temperature modelling in intelligent wells environments". Thesis, Heriot-Watt University, 2007. http://hdl.handle.net/10399/63.
Texto completoSmith, Stephen Roy Walter. "Remote optical fibre temperature and groundwater sensing". Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266224.
Texto completoKennedy, Jermaine L. "Investigations of fiber optic temperature sensors based on Yb:Y3Al5O12". [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001566.
Texto completoWang, Jun. "Packing design of MEMS pressure, temperature and other sensors". Mémoire, École de technologie supérieure, 2008. http://espace.etsmtl.ca/623/1/WANG_Jun.pdf.
Texto completoAgbor, N. E. "Gas sensors using organic thin films at room temperature". Thesis, Durham University, 1993. http://etheses.dur.ac.uk/5694/.
Texto completoPage, Julian. "Factors affecting low temperature performance of zirconia gas sensors". Thesis, Middlesex University, 2001. http://eprints.mdx.ac.uk/8007/.
Texto completoMohammadazari, Pejman. "Application of Capacitive Temperature Sensors for Food Processing Applications". Thesis, Southern Illinois University at Edwardsville, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13421017.
Texto completoThis thesis presents the design, analysis and optimization of a MEMS capacitive temperature sensor. The capacitive sensors are utilized in a wide range of applications from industrial and automotive applications to biomedical and food processing. A capacitive sensor has two conductive electrodes and its working principle depends on the change in the position of the electrodes or their effective area, which ultimately results in a change in the capacitance of the device. This thesis describes the modeling and the simulation results of a capacitive temperature sensor with a set of bimorph beams working as thermal actuators. The thermal actuator creates out-of-plane displacements and changes the distance between the electrodes as the ambient temperature changes. The presented bimorph capacitive temperature sensor consists of two bilayer silicon-gold beams and two capacitive electrodes, one of them is fixed to the substrate and the second one is connected to the beams. Different beam sizes and electrode shapes are designed and simulated and the characteristics capacitance-temperature (C-T) response of the sensor is obtained. The goal of this work is to modify and optimize the sensor geometry such that the C-T response is more linear, providing nearly constant sensitivity. ANSYS mechanical APDL is used as the finite element software for simulation and optimization of the sensor design, and coupled-field multiphysics solver is utilized to solve the electrostatic and structural domains. The simulation results show that for a given fabrication process, where the thickness of the structural and sacrificial layers in fabrication process is fixed, it is possible to modify the dimensions and geometry of the sensor such that a C-T response with high linearity is obtained.
Vysniauskas, Aurimas. "Molecular rotors as sensors of microscopic viscosity and temperature". Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/55240.
Texto completoLoskutova, Ksenia y Daniel Neuman. "3D-printed temperature sensors based on Fiber Bragg Gratings". Thesis, KTH, Skolan för teknikvetenskap (SCI), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195841.
Texto completoSving, Andreas. "Investigation of High-Temperature Sensors for Tube Monitoring Applications". Thesis, Uppsala universitet, Solcellsteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-434360.
Texto completoZhu, Yizheng. "Miniature Fiber-Optic Sensors for High-Temperature Harsh Environments". Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/27762.
Texto completoPh. D.
Hurley, Paul Raymond. "Application of Optical Fiber Sensors for Quenching Temperature Measurement". Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99035.
Texto completoMaster of Science
There are multiple types of boiling that can occur depending on the heat transfer capabilities of the system and the power applied to the coolant. The most common is nucleate boiling, where vapor produced at the surface forms bubbles and move away from the surface due to buoyancy. At a high enough power, the bubbles can coalesce into a film and lead to a point at which the liquid coolant can no longer contact the surface. Since vapor is not as effective at transferring heat from the surface, the temperature will increase drastically. In nuclear reactors, this situation (known as departure from nucleate boiling), can quickly lead to a meltdown of the fuel rods. Another important safety parameter in nuclear reactors is the minimum temperature at which this vapor film can be maintained, Tmin. This parameter is a source of significant concern with regard to accident scenarios such as LOCA (loss of coolant accident), where reintroducing coolant to the rods efficiently is of top priority. While much research has been done on nucleate and film boiling, it has been difficult to study the transition period between the two regimes due to both its transient nature and the lack of continuous measurement capabilities. Typically, temperature is measured using thermocouples, which are point-source sensors that do not allow for high spatial resolution over a large area. This thesis deals with the utilization of optical fibers for temperature measurement, which are capable of calculating data at every millimeter, potentially a much more precise measurement system than with the thermocouples. The experiments performed in this paper are quenching experiments, where a rod embedded with thermocouples and an optical fiber is heated to well above Tmin and quickly plunged into a volume of water, in order to view the transition from film to nucleate boiling.
Wang, Zhiyong. "Self-Calibrated Interferometric/Intensity Based Fiber Optic Temperature Sensors". Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/9690.
Texto completoMaster of Science
Trontz, Adam J. "Metal-Ceramic Coaxial Cable Sensors for Distributed Temperature Monitoring". University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522165065943505.
Texto completoYoo, Seung-jin. "Micromachined wavelength selective microbolometer sensors operating at room temperature /". Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004406.
Texto completoMOISELLO, ELISABETTA. "Integrated Interface Circuits for MEMS Contact-less Temperature Sensors". Doctoral thesis, Università degli studi di Pavia, 2020. http://hdl.handle.net/11571/1370177.
Texto completoThermal sensors, exploiting the relation between the thermal radiation emitted by an object and its temperature, as expressed by the Stefan-Boltzmann law, allow realizing contact-less temperature measurements, required in a wide range of applications, ranging from fever measurements to presence detection for security and climate control systems. With the advent of smart homes and Internet of Things (IoT) and the wide spreading of mobile and wearable devices, the need for low-cost low-power thermal sensors has arisen, therefore moving the focus of the research away from standard bolometers and pyroelectric detectors and towards uncooled infrared (IR) sensors solutions that can be easily integrated. Bolometers and pyroelectric detectors, which are the main types of thermal sensors found nowadays on the market, in fact, do not comply with the low-cost and easy integration specifications. Integration of thermal sensors is possible through Micro-Electro Mechanical Systems (MEMS) technology, which allows combining on the same substrate or chip both electrical and mechanical structures with dimensions in the micro-meter range, thus providing structures with high thermal isolation and low thermal mass. The micromachining processes that are required to thermally isolate the sensing element from the substrate are versatile and include anisotropic wet etching, dry and wet etching, electrochemical etch stop, or the use of silicon-on-insulator (SOI). In this scenario, STMicroelectronics has fabricated two different novel thermal sensors, which fulfill the low-cost low-power specifications for smart homes, IoT and mobile and wearable devices, while also being compatible with CMOS processes and thus easily integrated: a polysilicon thermopile and a micromachined CMOS transistor, from now on referred to as TMOS. During my Ph.D. activity I was involved in a cooperation between the STMicroelectronics Analog MEMS and Sensors R&D group and the University of Pavia, that led to the design of two readout circuits specifically tailored on the sensors characteristics, one for the thermopile sensor and one for the TMOS (developed by the Technion-Israel Institute of Technology), which were integrated in two test-chip prototypes and thoroughly characterized through measurements as stand-alone devices and as a system with the sensor they were designed for.
Firebaugh, Samara L. "Investigation of materials for use in high-temperature, thin-film heaters and temperature sensors". Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43402.
Texto completoWeber, Nicole. "Using landscape metrics to assess traffic noise, air pollution and temperature conditions". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17196.
Texto completoIn cause of their high population-density as well as social and economic importance, urban areas are particularly sensitive to external influences and environmental pollution. Under climate change and high noise and air pollution, green spaces, such as parks and urban forests, become increasingly important. The identification of highly polluted areas within the city or its residential districts can be helpful for city planners to proactively plan these areas and create open spaces. Sustainable effects on well-being and human health will be the outcome. The dissertation implemented an environmental risk analysis has been based on the quantitative concept of the landscape metrics. Typical structure types in Leipzig have been analysed for their exposure to traffic noise, air pollution and surface temperatures. The highest exposures of noise and airborne particles, as well as the highest surface temperatures were found in residential areas. In contrast green spaces and allotments form recreation areas with lower surface temperatures and high percentages of low exposured areas of noise and air pollution. A simultaneous analysis of existing structural features, building height and proportion of built area, allowed the consideration of the influence of certain structural conditions. The use of landscape metrics offered a cost-efficient analysis of the structure types and the prevailing exposure of the three environmental stressors. Bases on metrics such as edge and patch density and diversity indicés, land use structure changes going along with improvements or worsening of air and noise pollution as well as surface temperatures can be straightforward identified.
Barnes, Adam. "Sapphire fiber in optical sensors". Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-09052009-041053/.
Texto completoWu, Zhaohui. "Modeling and characterization of high-temperature silicon-based thermal sensors". Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31057652.
Texto completoFrood, Andrew J. M. "Thick-film Piezoelectric resonant sensors : MEMS and High Temperature Solutions". Thesis, University of Southampton, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505870.
Texto completoChong, N. "Room-temperature GaAs and polysilicon thermal sensors for infrared radiation". Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597637.
Texto completoWu, Zhaohui y 吳朝暉. "Modeling and characterization of high-temperature silicon-based thermal sensors". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B31057652.
Texto completoBezombes, Frédéric. "Fibre Bragg grating temperature sensors for high-speed machining applications". Thesis, Liverpool John Moores University, 2004. http://researchonline.ljmu.ac.uk/5630/.
Texto completoBeech, Alison. "An investigation of novel low-temperature carbon monoxide gas sensors". Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/33096.
Texto completoChalyy, D. y I. Zhidenko. "Fiber-optical temperature sensors for operation in radiation-hazard conditions". Thesis, XII Міжнародна науково-практична конференція молодих вчених, курсантів та студентів «Проблеми та перспективи розвитку системи безпеки життєдіяльності». – Л., 2017. – С.29, 2017. http://hdl.handle.net/123456789/3978.
Texto completoTonks, Michael James. "Modeling and Testing of Fast Response, Fiber-Optic Temperature Sensors". Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/26075.
Texto completoPh. D.
Zhang, Yibing. "Novel Optical Sensors for High Temperature Measurement in Harsh Environments". Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/28392.
Texto completoPh. D.
Twedt, Jason Christopher. "Fiber-Optics Based Pressure and Temperature Sensors for Harsh Environments". Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/42782.
Texto completoMaster of Science
Crenshaw, Brent R. "PHOTOLUMINESCENT POLYMER MATERIALS WITH BUILT-IN DEFORMATION AND TEMPERATURE SENSORS". Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1169825895.
Texto completoAbeysinghe, Don Chandana. "Novel MEMS Pressure and Temperature Sensors Fabricated on Optical Fibers". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin997987327.
Texto completoPatil, Amita C. "Silicon Carbide JFET Integrated Circuit Technology for High-Temperature Sensors". Cleveland, Ohio : Case Western Reserve University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1238786695.
Texto completoKRIK, Soufiane. "Low-operating temperature chemiresistive gas sensors: Fabrication and DFT calculations". Doctoral thesis, Università degli studi di Ferrara, 2021. http://hdl.handle.net/11392/2488099.
Texto completoI sensori di gas basati sugli ossidi metallici semiconduttori (MOX) si sono rivelati negli ultimi anni una tecnologia estremamente vantaggiosa. Nonostante i progressi fatti in questo campo, questi dispositivi presentano ancora alcuni punti deboliche spingono la ricerca ad effettuare ulteriori indagini per perfezionare il loro funzionamento. I ricercatori hanno cercato di risolvere questi svantaggi in diversi modi, focalizzandosi sullo sviluppo di MOX innovativi, tra cui il drogaggio tramite l’utilizzo di additivi o l’introduzione nel materiale di vacanze di ossigeno a concentrazione controllata. Questa’alternativa sta attirando l’attenzione di molti gruppi di ricerca, anche se, ad oggi, la letteratura scientifica presenta una mancanza di studi su come la disposizione e concentrazione di vacanze di ossigeno influenzano le performance di sensing e solo alcuni lavori preliminari hanno portato a risultati interessanti. Per cercare di ovviare ai limiti dei sensori MOX, una seconda via è stata lo sviluppo e di materiali 2D basati su solfuri metallici, grafene o similari. Il fosforene è uno dei migliori candidati per tale applicazione tecnologica, poiché mostra un'attività elettrica anche a temperatura ambiente, anche se studi preliminari hanno evidenziato un alto tasso di degradazione nel tempo del materiale durante il suo utilizzo. L'obiettivo di questo lavoro è quello di diminuire la temperatura di funzionamento di sensori di gas basati su SnO2 sfruttando il controllo delle vacanze di ossigeno. A tale scopo, è stato fatto inizialmente uno studio della letteratura e un’analisi analitica nell’ambito della DFT per indagare come le vacanze di ossigeno influenzano le proprietà fisico-chimiche del materiale. È stato studiato l'effetto di due diverse concentrazioni di vacanze di ossigeno sulle proprietà chimico-fisiche dello SnO2 bulk. Successivamente è stata studiata la formazione della vacanze in superficie per investigare l'adsorbimento di molecole di ossigeno dall'atmosfera circostante sulla superficie dello SnO2 è stato sintetizzato tramite sintesi sol-gel e la riduzione è stata ottenuta tramite trattamento termico in presenza di H2 a diverse temperature. I risultati hanno mostrato un'alta risposta dei sensori basati su SnO2-x in presenza di basse concentrazioni di NO2 spostando a 130 °C la temperatura ottimale di funzionamento del dispositivo. Questa diminuzione della temperatura operativa implica una diminuzione del consumo energetico del dispositivo Come menzionato precedentemente, il fosforene è uno dei materiali 2D più promettenti per lo sviluppo di sensori di gas chemoresistivi, ma presenta ancora alcuni svantaggi. Molti studi sono stati sviluppati sulla decorazione del fosforene con atomi metallici al fine di migliorare le sue prestazioni per diverse applicazioni tecnologiche, ma non sono stati ancora condotti studi specifici su questa particolare forma di fosforene decorato per applicazioni di sensoristica gassosa. Nello studio qui proposto, sono stati eseguiti calcoli DFT per spiegare come il nichel influenzi le proprietà elettroniche del fosforene, poiché la decorazione con nichel ha mostrato una migliore stabilità del sensore e un’alta sensibilità all’NO2. Tramite simulazione DFT è stato possibile investigare l'adsorbimento delle molecole di ossigeno sul Fosforene tal quale e decorato con nichel. I risultati hanno evidenziato che le molecole di ossigeno si dissociano sullo strato di fosforene tal quale e reagiscono con gli atomi di fosforo, ossidandolo, mentre in presenza dei cluster di nichel è quest’ultimo a svolgere il ruolo di catalizzatore, interagendo con le molecole di ossigeno. Infine, il meccanismo di interazione tra NO2 e la superficie del fosforene tal quale e funzionalizzato è stato caratterizzato teoricamente studiando il trasferimento di carica che avviene sulla superficie del materiale in esame.
Khalil, Nahla Mahmood. "Novel optoelectronic temperature sensor having application in the biomedical field". Thesis, City University London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328417.
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