No description available.

D.Ing.

Giving feedback to households about their energy consumption has been seen by many as a necessity in order for households to reduce their energy consumption and lower their carbon footprint. Many studies have been made on how smart meters, that give feedback on the total consumption, are used and their effect on the consumption. However, fewer studies have been done on how disaggregated feedback is understood and acted upon. Smappee is an energy feedback system that monitors the household’s consumption and is able to detect appliances’ consumption with only 3 physical clamps at the incoming current, using non-intrusive load monitoring (NILM). NILM differentiate appliances based on their electrical signature which is generated by turning an appliance on and off. The users get the feedback through a smartphone application. This study attempts to answer the question “How do users understand and act upon disaggregated feedback in Smappee?” by doing a qualitative study based on contextual interviews made on 15 users of Smappee. The results of the interviews are then compared with previous studies within the field of smart meters and a conceptual model is being described of how users understand Smappee. The results show that disaggregated feedback in Smappee is perceived as too difficult to acquire. Users thought it was too hard to find which appliances represented in Smappee correspond to which physical appliances in the household. However, the users used the real-time total consumption in order to make an estimation of how much certain appliances consumed. This indicates that users are interested in disaggregated feedback if it is easily accessible. Users have, in general, a good understanding of how Smappee detects appliances. They understand that Smappee is measuring the incoming current and makes assumptions based on the increases and decreases. They did not use the disaggregated feedback, even though they understood how it worked. / Att ge feedback till hushåll om deras energikonsumtion har setts, av många, som en nödvändighet för att hushåll ska kunna reducera sin energikonsumtion och minska sina koldioxidutsläpp. Flera studier har gjorts om hur smarta mätare, som ger feedback om totalkonsumtionen, används och deras effekt på förbrukningen. Men färre studier har gjorts om hur uppdelad feedback förstås och hur användare agerar på detta. Smappee är ett energifeedbacksystem som mäter hushålls konsumtion och är kapabel att detektera apparaters konsumtion med endast 3 klamrar på den inkommande strömmen, genom att använda “non-intrusive load monitoring (NILM). NILM skiljer på apparater baserat på deras elektriska signatur som genereras av att sätta på och slå av apparater. Användarna får feedbacken i en Smartphone-applikation. Denna studie försöker besvara frågan: “Hur förstår och agerar användare på uppdelad feedback i Smappee?” genom att genomföra en kvalitativ studie baserad på kontextuella intervjuer genomförda med 15 användare av Smappee. Resultatet från intervjuerna är sedan jämförda med tidigare studier inom området smarta mätare och en konceptuell model beskrivs om hur användare förstår sig på Smappee. Resultatet visar att uppdelad feedback i Smappee uppfattas för svår att använda. Användarna upplevde att det var för svårt att finna vilken apparat i Smappee som korresponderar till en viss fysisk apparat i hushållet. Dock använde användarna realtidskonsumtionen för att skapa en uppskattning om hur mycket vissa apparater konsumerade. Detta indikerar att användarna hade ett intresse i uppdelad feedback om det var tillgängligt på ett lättare sätt. Användare har, i allmänhet, en god förståelse om hur Smappee detekterar apparater. De förstår att Smappee mäter inkommande ström och gör antaganden baserat på ökningar och minskningar. De använde inte uppdelad feedback även om de förstod hur det fungerade.

The city of Cape Town suffered a severe water crisis in 2018. At the peak of the drought in South Africa’s Western Cape, a randomised control trial at 105 schools investigated the impact of two behavioural interventions to encourage responsible water usage: detailed water usage data feedback from smart meters, and an interschool competition. Interventions reduced water usage in these schools by 15 to 26%. The information feedback was found to be more effective in reducing night time water use, indicating better water usage by the staff, while the competition was found to be more effective during the day time, indicating better water usage by the pupils. The contrast highlights the way feedback was understood differently by the two groups, with different effects on their assumption of responsibility. This example from Cape Town demonstrates the effectiveness of combining smart technologies with nudges. It provides a model of water conservation interventions for sustainable cities.

The Digital Multifunction Power Measuring System is the outgrowth of a project involving the design of a prototype precision Digital Watt Transducer for the Bonneville Power Administration (BPA). A prototype Digital Watt Transducer was built and tested since no other device of the desired accuracy was connnercially available. Upon partial completion of the project, another Watt Transducer did become available which was essentially identical to our development. Since we could not economically compete with the manufacturer of these Watt Transducers, our project was stopped. Over a period of several months we thought about other ways to apply the experience gained from the Watt Transducer project, and came upon the idea of designing a precision multifunction power meter to help simplify the calibration of Watt and VAR transducers in the Instrumentation and Standards Laboratory, and possibly replace approximately five less accurate analog meters presently used by our Meter-Relay Craftsmen in their field testing. Since no similar meter was available, and since possible revenues lost to inaccurate measurement could justify the development costs of such a meter, we were given authorization to design and build it. This instrument is the Digital Multifunction Power Measuring System which measures the following electrical parameters to approximately plus or minus one-tenth of one percent or better accuracy: True RMS AC Volts in two ranges; True RMS AC Amps in six ranges; Watts in twelve ranges; VARs in twelve ranges; Phase Angle between Volts and Amps in all ranges; DC Volts in three ranges. This instrument has been completed, tested, and calibrated to its design accuracies and is presently being demonstrated within the BPA system to make its availability known to those personnel who might have need for such an instrument.

No description available.

The first objective of this problem - thorough literature review - was conducted on all available references concerning humidity measurement, and visits were made to the American Instrument Company in Silver Springs, Maryland, and the National Bureau of Standards. The survey evaluated the instruments in use today and also explored many of the ideas and concepts that have been suggested in past years as possible means for humidity measurement. A summation of the survey indicated that the electric hygrometer with a ceramic element was a good basic theory for a humidity instrument, but still required development before it,would be of any practical use. The second objective - development of a useful hygrometer - was directed towards the development of the electric hygrometer using a ceramic element. The study that resulted included the evaluation of two methods for determining the change of resistance of the ceramic element, as well as a preliminary investigation of the characteristics of a ceramic element when employed as the sensing element for an electric hygrometer. The element intended for the initial tests, a porous ceramic containing mostly aluminum oxide, was the only material tested, but the tests included elements of the pure ceramic material and the same material after it was soaked in a saturated solution of lithium chloride. With the instruments used, the indications were that both elements were suited for determining the high humidities. The pure element had a lower limit of 50 percent relative humidity, and the coated element a lower limit of 20 percent. Two instruments were used for indicating the change of relative humidity. A vacuum tube voltmeter type instrument was tested, but found unsatisfactory due to variations of readings under the same conditions, drifting of the zero set, and excessive fluctuations of the indicating meter. The other instrument or method used was to apply an A-C voltage across the element, and to measure the resulting current flow. Because the current was maintained above 1 milliampere, heating of the element was caused, resulting in a change of element resistance. However, results with this instrument were sufficient to establish a calibration curve for the apparatus. A comparison of this device and a psychrometer indicated the usefulness of such an instrument, but confirmed that the development was not complete. The overall result of the research indicates that the selection of the ceramic sensing element for an electric hygrometer has merit, but more development is necessary. Two phases of any future work on the problem should be the development of the indicating instrument, and the selection and design of the sensing element. The need for a satisfactory instrument still exists, and the successful development of the type instrument described herein, would undoubtedly meet the requirements. / Master of Science

An experimental investigation of an opposed flow hydrogen-air diffusion flame was conducted. The purpose was to experimentally determine the flow field velocity and corresponding strain rate under different operating flow conditions. An axisymmetric opposed jet burner was employed in this experiment where air was supplied to one circular tube, while fuel and diluent were supplied to the opposing circular tube. Velocity measurements were made under two different operating flow rates, via the laser Doppler anemometer. The experimental results are used to assess current counterflow diffusion flame modeling approximations. The data shows that the radial velocity is approximately linear with radial coordinate, as assumed by most modelings. The boundary conditions (uniform axial velocity, and linear radial velocity) assumed by the potential flow model are appropriate at a particular location upstream of the boundary layer region; and the supply air strain rate approximates the potential flow strain rate, going into the flame boundary layer region. Qualitatively, the plug flow model is a better approximation to the velocity distribution for both flow cases. / Master of Science

This thesis deals with flow measuring techniques applied to steady and pulsating gas flows relevant to gas exchange systems for internal combustion engines. Gas flows in such environments are complex, i.e. they are inhomogeneous, three-dimensional, unsteady, non-isothermal and exhibit significant density changes. While a variety of flow metering devices are available and have been devised for such flow conditions, the performance of these flow metersis to a large extent undocumented when a strongly pulsatile motion is superposed on the already complex flow field. Nonetheless, gas flow meters are commonly applied in such environments, e.g. in the measurement of the air flow to the engine or the amount of exhaust gas recirculation. The aim of the present thesis is therefore to understand and assess, and if possible to improve the performance of various flow meters under highly pulsatile conditions as well as demonstrating the use of a new type of flow meter for measurements of the pulsating mass flow upstream and downstream the turbine of a turbocharger. The thesis can be subdivided into three parts. The first one assesses the flow quality of a newly developed flow rig, designed for measurements of steady and pulsating air flow at flow rates and pulse frequencies typically found in the gas exchange system of cars and smaller trucks. Flow rates and pulsation frequencies achieved and measured range up to about 200 g/s and 80 Hz, respectively. The time-resolved mass flux and stagnation temperature under both steady and pulsating conditions were characterized by means of a combined hot/cold-wire probe which is part of a newly developed automated measurement module. This rig and measurement module were used to create a unique data base with well-defined boundary conditions to be used for the validation of numerical simulations, but in particular, to assess the performance of various flow meters. In the second part a novel vortex flow meter that can measure the timedependent flow rate using wavelet analysis has been invented, verified and extensively tested under various industrially relevant conditions. The newly developed technique was used to provide unique turbine maps under pulsatile conditions through time-resolved and simultaneous measurements of mass flow, temperature and pressure upstream and downstream the turbine. Results confirm that the quasi-steady assumption is invalid for the turbine considered as a whole. In the third and last part of the thesis, two basic fundamental questions that arose during the course of hot/cold-wire measurements in the aforementioned high speed flows have been addressed, namely to assess which temperature a cold-wire measures or to which a hot-wire is exposed to in high speed flows as well as whether the hot-wire measures the product of velocity and density or total density. Hot/cold-wire measurements in a nozzle have been performed to test various hypothesis and results show that the recovery temperature as well as the product of velocity and stagnation density are measured. / QC 20120510

Los cambios que ha traído consigo la tecnología han ocasionado que muchos negocios sean más exigentes en el control de sus procesos y que busquen contantemente reducir sus costos a través de esta. Por ello la innovación es un punto importante en estos cambios que llamamos transformación digital – entendida como la capacidad digital en los procesos, productos y activos para mejorar la eficiencia- permitiendo que las empresas busquen nuevas maneras de hacer las cosas. Todos esos indicadores fueron un punto clave para identificar una oportunidad de negocio y ubicar nuestro nicho de mercado. Los negocios como restaurantes, hoteles y servicios en general, que su producción depende del gas GLP, no cuentan con una herramienta para medir su consumo ni saber cuándo deben volver a solicitar nuevamente gas. El presente negocio consiste en comercializar medidores digitales de gas GLP que sean compatibles con tanques estacionarios de hasta 1,320 GLN el cual trabaja junto con una aplicación móvil, ambos te permiten saber en tiempo real cuál es tu consumo actual, el consumo mensual promedio y cuando debes solicitar nuevamente gas. Por lo que podemos concluir que este emprendimiento satisface las necesidades de nuestro mercado objetivo. / Changes brought by new technology have made many businesses worry more about keeping control of their processes and constantly search for new ways to reduce cost through it. That is why innovation is an important point in these changes we call digital transformation – understood as the digital capacity of processes, products and assets to improve efficiency –allowing companies to find new ways to achieve their objectives. All the facts mentioned before, were the key point to identify a business opportunity and the right market niche to develop it. Businesses like restaurants, hotels and other service providers, with a need of GLP gas to operate, don’t have a precise way to measure their consumption nor know when they need to call for a refill to avoid unwanted pauses on their operations. The presented business plan proposes the marketing of digital GLP gas meter compatible with stationary tanks under 1,320 GLN capacity. This meter will work along with a custom designed mobile app, letting the business owner know in real time the tank occupancy level, as well as the present consumption, monthly average and estimated date to place a new purchase order for a refill. Considering this, we can conclude the present proposal covers and exceeds the needs and expectations of the target market. / Trabajo de investigación