Thermal Model of a Thin Film Pulsed Pyroelectric Generator

2016 ◽  
Author(s):  
Nicholas R. Jankowski ◽  
Andrew N. Smith ◽  
Brendan M. Hanrahan
Keyword(s):  
Thin Film ◽  
Power Generation ◽  
Energy Conversion ◽  
High Speed ◽  
High Energy ◽  
High Energy Density ◽  
Working Fluid ◽  
Film Material ◽  
Thermodynamic Cycles ◽  
The Impact

Recent high energy density thin film material development has led to an increased interest in pyroelectric energy conversion. Using state-of-the-art lead-zirconate-titanate piezoelectric films capable of withstanding high electric fields we previously demonstrated single cycle energy conversion densities of 4.28 J/cm3. While material improvement is ongoing, an equally challenging task involves developing the thermal and thermodynamic process though which we can harness this thermal-to-electric energy conversion capability. By coupling high speed thermal transients from pulsed heating with rapid charge and discharge cycles, there is potential for achieving high energy conversion efficiency. We briefly present thermodynamic equivalent models for pyroelectric power generation based on the traditional Brayton and Ericsson cycles, where temperature-pressure states in a working fluid are replaced by temperature-field states in a solid pyroelectric material. Net electrical work is then determined by integrating the path taken along the temperature dependent polarization curves for the material. From the thermodynamic cycles we identify the necessary cyclical thermal conditions to realize net power generation, including a figure of merit, rEC, or the electrocaloric ratio, to aid in guiding generator design. Additionally, lumped transient analytical heat transfer models of the pyroelectric system with pulsed thermal input have been developed to evaluate the impact of reservoir temperatures, cycle frequency, and heating power on cycle output. These models are used to compare the two thermodynamic cycles. This comparison shows that as with traditional thermal cycles the Ericsson cycle provides the potential for higher cycle work while the Brayton cycle can produce a higher output power at higher thermal efficiency. Additionally, limitations to implementation of a high-speed Ericsson cycle were identified, primarily tied to conflicts between the available temperature margin and the requirement for isothermal electrical charging and discharging.

scholarly journals Body Mass, Physical Activity and Eating Habits Changes during the First COVID-19 Pandemic Lockdown in Poland

2021 ◽  
Vol 18 (11) ◽  
pp. 5682
Author(s):  
Hubert Dobrowolski ◽  
Dariusz Włodarek
Keyword(s):  
Physical Activity ◽  
Body Weight ◽  
Body Mass ◽  
Social Life ◽  
Eating Habits ◽  
High Energy ◽  
High Energy Density ◽  
Average Weight ◽  
Study Participants ◽  
The Impact

The outbreak of the COVID-19 pandemic caused a number of changes in social life around the world. In response to the growing number of infections, some countries have introduced restrictions that may have resulted in the change of the lifestyle. The aim of our study was to investigate the impact of the lockdown on body weight, physical activity and some eating habits of the society. The survey involving 183 people was conducted using a proprietary questionnaire. The mean age of the study participants was 33 ± 11 and mean height 169 ± 8 cm. An average increase in body weight was observed in 49.18% by 0.63 ± 3.7 kg which was the result of a decrease in physical activity and an increase in food consumption. We also observed a decrease in PAL from 1.64 ± 0.15 to 1.58 ± 0.13 and changes in the amount of food and individual groups of products consumption, including alcohol. Among the study participants who did not lose body mass, there was an average weight gain of 2.25 ± 2.5 kg. In conclusion, an increase of weight was shown in about half of the respondents in the study group which was associated with a decrease in physical activity and an increase in the consumption of total food and high energy density products.

scholarly journals Editorial from the Editor in Chief: Impact factors and open access publishing

2006 ◽  
Vol 24 (4) ◽  
pp. 467-468
Author(s):  
Dieter H.H. Hoffmann
Keyword(s):  
Impact Factor ◽  
Ultrashort Pulses ◽  
Dense Matter ◽  
High Energy ◽  
Research Field ◽  
High Energy Density ◽  
Open Access Publishing ◽  
Impact Factors ◽  
Particle Beams ◽  
The Impact

The primary goal of Laser and Particle Beams as part of the Cambridge University Press is the dissemination of knowledge in our research field. How effective we are in this respect is not easy to determine. But the impact factor published annually in June by Thomson ISI® 2005 Journal Citation Reports (JCR), gives at least an indication and a method to compare other journals in the field. In this respect, Laser and Particle Beams is a journal with a very high ranking in the field of applied physics, but it also compares very well to journals in other field of physics. The impact factor of a journal gives an account of how often an average paper in the journal is referred to, in a two year time span after publication. The current impact factor of 2.59 is based on an evaluation conducted in 2005 of Laser and Particle Beams publications of 2003 and 2004. During the evaluation period (2005), Laser and Particle Beams publications were cited about 1000 times. The topics that attracted most attention were Fast Ignition (Deutsch, 2004; Mulser & Schneider, 2004a; Hora, 2004; Mulser & Bauer, 2004b), Inertial Fusion Targets (Borisenko et al., 2003), and Ion and Electron Acceleration in laser plasma and Ultrashort Pulses (Shorokhov & Pukhov, 2004; Osman et al., 2004; Malka & Fritzler, 2004; Limpouch et al., 2004; Pegoraro et al., 2004). However, the editorial boards of Laser and Particle Beams strongly encourage authors to submit their results in High Energy Density Physics, the emerging field of Warm Dense Matter, Pulsed Power and Accelerator Physics and Technology.

scholarly journals Metal-Water mixtures for Propulsion and Energy-Conversion Applications: Recent Progress and Future Directions

2018 ◽  
Vol 20 (1) ◽  
pp. 53 ◽  
Author(s):  
Dilip Sundaram
Keyword(s):  
Particle Size ◽  
Energy Conversion ◽  
Experimental Studies ◽  
High Energy ◽  
High Energy Density ◽  
Full Potential ◽  
Predictive Tool ◽  
Practical Applications ◽  
Relative Safety ◽  
Metal Water

The metal-water system is attractive for propulsion and energy-conversion applications. Of all metals, aluminum is attractive due to its high energy density, relative safety, and low cost. Experimental studies provide new insight on the combustion and propulsive behaviors. The burning rate is found to be a strong function of both pressure and particle size. Furthermore, there is a wide scatter in the measured pressure exponents due to differences in particle size, pressure, pH, and equivalence ratio. A major problem with Al/H2O mixtures is incomplete combustion and poor impulses, thereby rendering Al/H2O mixtures unsuitable for practical applications. Efforts to improve the performance of Al/H2O mixtures have only met with moderate success. Although experiments have revealed these new trends, not much is offered in terms of the underlying physics and mechanisms. To explore the combustion mechanisms, theoretical models based on energy balance analysis have been developed. These models involve numerous assumptions and many complexities were either ignored or treated simplistically. The model also relies on empirical inputs, which makes it more a useful guide than a predictive tool. Future works must endeavor to conduct a more rigorous analysis of metal-water combustion. Empirical inputs should be avoided and complexities must be properly treated to capture the essential physics of the problem. The model should help us properly understand the experimental trends, offer realistic predictions for unexplored conditions, and suggest guidelines and solutions in order to realize the full potential of metal-water mixtures.

New Highway Power Generation Device Based on Auto Wake

2013 ◽  
Vol 288 ◽  
pp. 172-174
Author(s):  
Jian Bo Xiao ◽  
Wei Gang Zheng ◽  
Yan Su
Keyword(s):  
Power Generation ◽  
Wind Energy ◽  
Energy Conversion ◽  
Wind Power ◽  
Power Supply ◽  
High Speed ◽  
Wind Power Generation ◽  
Supply Problem ◽  
Electric Equipment ◽  
The Government

With the increasingly serious environment pollution and energy shortage problem of further deepening, how to use more effective and more environmental protection equipment of the new energy conversion and utilization of become social the public and the government attaches great importance to the problem. According to the high speed highway car wake contains huge wind, the wind power generation unit born. The vertical shaft by double S rotor, wind deflector, variable speed clutch institutions, centripetal vertical pendulum and low speed generator composition , realized respectively the wind energy collection, transmission, temporary and transformation. This device for wind power generation field provides a more efficient energy conversion mode. Among them, we creatively applied the ratchet, vertical pendulum mechanism so that the wind energy conversion rate has been increased greatly. At the same time, can also solve the highway electric equipment of the power supply problem. This device design makes the highway lighting lamps and other electric equipment of the power supply problem to obtain the very good solve, reduce power facilities installation cost. The effective use of natural wind, expand the scope of the use of wind energy, alleviate energy nervous, also reduce the pollution of the environment.

Fast Pyrolysis Oil for Power Generation

2006 ◽  
Author(s):  
David Chiaramonti ◽  
Anja Oasmaa ◽  
Yrjo¨ Solantausta
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbines ◽  
Large Scale ◽  
Fast Pyrolysis ◽  
High Energy ◽  
High Energy Density ◽  
Current Status ◽  
Pyrolysis Oil

Biomass fast-pyrolysis oil (PO) is a liquid biofuel derived from lignocellulosic biomass: it offers several advantages compared to the direct us of solid bio fuels, such as high energy density, storability and transportability typical of liquid fuels, possibility to use the fuel in engines and turbines, easier downscaling of plants (which is a very important aspect for decentralized energy generation schemes). In addition, PO is the lowest cost biofuel, thus offering the possibility to penetrate also the large scale power generation market. Biomass POs have been studied and applications tested for many years, either for heat generation in medium-scale boilers or power generation. The present works reviews and analyses the most relevant experiences carried out so far and published results in power production from biomass PO. Power generation systems (PGS) which are here examined are gas turbines, diesel engines, stirling engines, as well as co-firing applications in large scale power plants (coal or natural gas plants). The main techniques for upgrading this biofuel and their impact on technologies are also shortly introduced and considered. The current status of development for each PO-based power generation option is discussed. This review work showed that long term demonstration (either technical or economical) is however still needed, even for the most developed technologies (use of PO in modified gas turbines and cofiring in natural gas stations): projects are on going to achieve long term demonstration.

A Concept of Energy Network Combined With Distributed Power Generation and Internet Systems

2002 ◽  
Author(s):  
Yoichi Tone ◽  
Kunihiko Mouri
Keyword(s):  
Power Generation ◽  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
The Internet ◽  
Network System ◽  
Distributed Power ◽  
Distributed Power Generation ◽  
Business Application ◽  
Energy Network

For the near future business application, the new idea of the distributed energy network system is proposed to secure lower cost and highly reliable power and heat supply system for the limited local area such as high energy density urban area. In Japan, tariff of the electric power is same for urban consumers and rural consumers under the present power law. However the wave of the power deregulation may affect to small business users and home users and the free-market of power purchase may emerge in public domain. Towards the realization of the future active power market, the new idea is created to promote the intelligent distributed power generation systems and heat utilization systems using the Internet application and local energy network construction. This system has been discussed in the consortium, consisting of Nagoya University, Gas Company, Power utility, Trade Company, IT Company etc since May 2000. The idea of the proposed eL-power network system is to supply necessary power and heat to the only customers in the high energy density area like near the railway station using energy management by mean of the Internet technologies.

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