Search results for " power"

Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor

2017

In the present work, the design and microfabrication of a tunneling magnetoresistance (TMR) electrical current sensor is presented. After its physical and electrical characterization, a wattmeter is developed to determine the active power delivered to a load from the AC 50/60 Hz mains line. Experimental results are shown up to 1000 W of power load. A relative uncertainty of less than 1.5% with resistive load and less than 1% with capacitive load was obtained. The described application is an example of how TMR sensing technology can play a relevant role in the management and control of electrical energy.

Application of artificial neural network and genetic algorithm to forecasting of wind power output

2007

Rural Population in Romania. Development and Tendencies (2000 – 2010)

2013

Abstract Demography is among the top factors which exert an undeniable influence upon the economic environment. Therefore, the populace - through its dynamics and characteristics - leaves an imprint upon the social and economic landscape, being a keen barometer and contributing to economic progress. The relationship demography-economy is extremely tight, since the populace is perceived as being a true representation of what characterizes our economy. Romania originated as a country with an agriculture-based economy – a fact which translated in its major rural population; nowadays, due to a sum of various developments, the rural populace is undergoing a decreasing trend. The situation is all…

Exploring dark creativity: the role of power in an unethical marketing task

2020

Creativity is seen as a significant driver for successful marketing activities. However, little attention is paid to its shady side and little research on the prerequisites for unethical behaviour of marketing experts and executives is on hand. In our experimental study, we examine the mutual influence of power, honesty-humility, and benevolent creativity as predictors for ‘dark creativity’ (the use of creative ideas for malevolent actions). Participants (N = 387) were randomly assigned to a high vs. low power condition (role of marketing director vs. marketing intern). Dark creativity was correlated to benevolent creativity, power motive, and honesty-humility, but did not depend on the pow…

Physical Performance During the Menopausal Transition and the Role of Physical Activity

2020

Abstract Background To examine longitudinal changes in physical performance during the menopausal transition and the role of physical activity (PA) in these changes. Methods Based on follicle-stimulating hormone levels and bleeding diaries, women (47–55 years) were classified as early (n = 89) and late perimenopausal (n = 143) and followed prospectively until postmenopausal status, with mean duration of 17.5 and 13.8 months, respectively. Physical performance was measured by handgrip force, knee extension torque, vertical jumping height, maximal walking speed, and 6-minute walking distance. Physical activity was self-reported and categorized as inactive, low, medium, and high. Longitudinal …

Comparison of inter-trial recovery times for the determination of critical power and W' in cycling

2017

Critical Power (CP) and W’ are often determined using multi-day testing protocols. To investigate this cumbersome testing method, the purpose of this study was to compare the differences between the conventional use of a 24-h inter-trial recovery time with those of 3 h and 30 min for the determination of CP and W’. Methods: 9 moderately trained cyclists performed an incremental test to exhaustion to establish the power output associated with the maximum oxygen uptake (p V O2max), and 3 protocols requiring time-to-exhaustion trials at a constant work-rate performed at 80%, 100% and 105% of p VO2max. Design: Protocol A utilised 24-h inter-trial recovery (CP24/W’24), protocol B utilised 3-h in…

Passive Control of Linear Structures Equipped with non-Linear Viscous Dampers and Amplification Mechanism

2008

Fluid damper devices in civil structures such as buildings or bridges are commonly used as energy absorbers for seismic protection. The problem in the response analysis of structures with filled dampers mainly consists in the fact that, due to the strongly nonlinear behavior of such equipments, the response spectrum technique fails. Moreover, in order to enhance the damping effect various toggle brace configurations have been recently proposed. In this paper by using the concept of power spectral density function compatible with the elastic response spectrum and the stochastic linearization technique, the equivalent damping ratio is obtained. It is shown that once the system is linearized r…

Miten opettaja rakentaa pedagogisen auktoriteetin? Otteita opettajan arjesta

2002

Laadullisen tutkimuksen päätavoitteena oli pureutua siihen, miten opettaja ymmärtää ja rakentaa pedagogisen auktoriteettinsa koulun arjessa. Koska auktoriteettisuhde ei todennu ajatuksissa, puheessa ja kuvitelmissa, tutkin myös, miten auktoriteetti toimii ja saa oikeutuksen luokkatilanteessa. Pedagoginen auktoriteetti liitetään taustakirjallisuudessa toisaalta varsinaisen vallankäytön ulkopuoliseen, kasvatukseen liittyvään auktoriteettisuhteeseen, toisaalta korostetaan henkilösuhteen merkitystä auktoriteettisuhteen muotoutumisessa. Työn peruskysymys on sama kuin työn nimi: Miten opettaja rakentaa pedagogisen auktoriteetin? Osakysymyksiä ovat seuraavat: Mitä ilmiöön pedagoginen auktoriteetti…

Waste heat recovery from a marine waste incinerator using a thermoelectric generator

2012

Published version of an article published in the journal: Journal of Electronic Materials. Also available from the publisher at: http://dx.doi.org/10.1007/s11664-012-2009-6 A marine waste incinerator has been evaluated for waste heat harvesting using thermoelectric generators (TEG). The application has been evaluated using mathematical modeling to optimize the heat exchanger and some vital design parameters of the TEG. The calculation shows that it is possible to extract 58 kW el at a price of 6.6 US$/W from an 850-kW th incinerator when optimizing for maximum power. However, minimizing the cost, it is possible to get 25 kW el at a price of 2.5 US$/W. A trade-off between the two targets lea…

NH4HCO3–water solutions regeneration in RED closed loop applications

2017

Reverse Electrodialysis (RED) in closed loop arrangement (Reverse Electrodialysis Heat Engine - REDHE) is a promising technology to convert low-grade waste heat into electricity. RED is a membrane process exploiting the salinity gradient between a concentrated and a diluted solution to generate electrical current. Due to the transfer phenomena occurring in the RED unit, the two exiting solutions are partially mixed. Thermal regeneration processes can be used to restore the initial conditions of the two solutions, thus closing the loop. In this regard, ammonium hydrogen carbonate (NH4HCO3) salt solutions are suitable for such applications, being able to decompose at temperatures above 40-45 …