Search results for "Heating"
showing 10 items of 248 documents
Simple Lossless Inductive Snubbers-Assisted Series Load Resonant Inverter Operating under ZCS-PDM Scheme for High-Frequency Induction Heating Fixed R…
2022
This paper presents a high-frequency pulse-density-modulated (PDM) soft-switching series load resonant inverter for use in induction heating (IH) fixed roller applications, which is used in copy and printing machines. The proposed simple high-frequency resonant inverter uses an asymmetrical pulse pattern PDM control scheme to achieve complete zero-current soft-switching commutations over a wide output range of input power regulation. Additionally, when the printer toner requires operation in very light load conditions, this causes difficulty in achieving zero-voltage or zero-current soft-switching operations in the IH high-frequency resonant inverters with pulse frequency modulation or puls…
Thermally Tunable Surface Acoustic Wave Cavities
2020
We experimentally demonstrate the dynamical tuning of the acoustic field in a surface acoustic wave (SAW) cavity defined by a periodic arrangement of metal stripes on LiNbO3 substrate. Applying a dc voltage to the ends of the metal grid results in a temperature rise due to resistive heating that changes the frequency response of the device up to 0.3%, which can be used to control the acoustic transmission through the structure. The timescale of the switching is demonstrated to be of about 200 ms. In addition, we have also performed finite-element simulations of the transmission spectrum of a model system, which exhibits a temperature dependence consistent with the experimental data. The adv…
Energy Efficiency and Sustainability of Different Building Structures in Latvian Climate
2015
Five experimental test buildings have been built in Riga, Latvia. They are identical except external walls for which different mainly regional building materials are used. Calculated U-values of the other walls, floor and ceiling are the same for each test building. Initial moisture influences the relative humidity of indoor air, which can be higher in the initial time period; as a result, heat transmittances are also very different and cause different heating/cooling energy consumption. Overheating risk in summer exists for test buildings with the smallest thermal inertia. Both summer and heating seasons have been analysed and differences between five test houses have been discussed in det…
Solar heating and cooling systems versus conventional systems assisted by photovoltaic: Application of a simplified LCA tool
2016
Abstract Life Cycle Assessment (LCA) is an effective methodology to assess the energy and environmental impacts of energy systems during their life cycle, including manufacturing, operation and end-of-life. The aim of the paper is the application of a simplified LCA tool, developed in the framework of the International Energy Agency Solar Heating and Cooling Task 48, for comparing different typologies of solar assisted heating and cooling systems. In detail, solar thermal heating and cooling systems located in Palermo (southern Italy) and in Zurich (Switzerland) were compared with conventional systems assisted by grid connected and stand-alone photovoltaic plants. A validation of the tool w…
Social Interactions Among Bacteriophages
2020
Although viruses lack many of the social adaptations shown by more complex organisms, different types of social interactions have been unraveled in viruses. Phage research has contributed significantly to the development of this field, called sociovirology, with the discovery of processes such as intracellular and extracellular public good production, prudent host exploitation, cheating, and inter-phage communication. We here review and discuss these processes from a social evolution approach. Similar to other organisms, the origin and maintenance of phage-phage interactions can be explained using kin selection, group selection and game theory approaches. Key determinants of phage social ev…
The Role of Technology in Participative Processes
2016
Smart city is more and more, in the common feeling, the crossroad of technologies, but first and foremost, the place where humans, contexts and technologies meet and must interact. Technological systems thanks to the deep human interaction acquire an uncertain behaviour that can be hardly modelled and controlled. The resulting complexity, cannot be easily handled with the tools that are available to separate scientific fields. The interdisciplinarity that comes from the implementation of technologies and the dialogue between these and the territories requires new tools for classification and design. New urban design tools are needed allowing to identify in a standardized way adequate suppor…
Energy modelling studies of thermochromic glazing
2010
Theoretically thermochromic glazing has the potential to reduce energy consumption in buildings by allowing visible light for day lighting, reducing unwanted solar gain during the cooling season, whilst allowing useful solar gain in the heating season. In this study building simulation is used to predict the savings made by novel thermochromic glazing coatings compared to standard products, for locations with different climates. The results suggest that thermochromic glazing can have a significant energy saving effect compared to current approaches.
Analysis and Improving Methods of Efficiency of Solar Energy in Municipal Heating System
2011
This paper introduces the current state of solar heating system among Wanzleben city heating net. In view of low efficiency (only 20-30%) of this system, it analyses the shortcomings of this applied system from sensors' situation, fixed flow problem, the influence of the user's water temperature and the length of pipe separately. Some improving methods which are effective by theoretical analysis are suggested. The implementation steps have to be discussed in more detail with the utility.
The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
2020
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. While the abundance of light elements indicates that the Universe was radiation dominated during Big Bang Nucleosynthesis (BBN), there is scant evidence that the Universe was radiation dominated prior to BBN. It is therefore possible that the cosmological history was more complicated, with deviations from the standard radiation domination during the earliest epochs. Indeed, several interesting proposals regarding various topics such as the generation of dark matter, matter-antimatter asymmetry, gravitational waves,…
Moral Disengagement in Youth Athletes: A Narrative Review
2022
The sports environment can be considered as a context characterized by interactions typical of social groups, where children have the chance to learn good values. Positive and negative behaviours in sports, also called prosocial and antisocial behaviours, have been studied according to a moral perspective, as has doping behaviour, taking into consideration the concept of moral disengagement. Moral disengagement in children has been associated with maladaptive behaviours later in life, even though it should disappear with growth. Concerning the sports environment, previous reviews on the topic have extensively illustrated the role of moral variables in sport and their relation to antisocial …