scholarly journals THE RELATIONSHIP BETWEEN THE SURFACE APPEARANCE AND DEPTH OF DAMAGE OF SUBFABRIC AND BARE SKIN BURNS PRODUCED BY RADIANT THERMAL ENERGY

1958 ◽  
Author(s):  
K. M. Berkley
Keyword(s):  
Thermal Energy ◽  
Surface Appearance ◽  
The Relationship

Economic Optimization of a Combined Heat and Power System for an Office Building

2007 ◽  
Author(s):  
M. E. Douglas ◽  
Timothy C. Wagner ◽  
Michael K. Sahm ◽  
William J. Wepfer
Keyword(s):  
Thermal Energy ◽  
Waste Heat ◽  
Cost Effective ◽  
Energy Generation ◽  
Prime Mover ◽  
Economic Optimization ◽  
Electrical Efficiency ◽  
Load Demand ◽  
Generation Cost ◽  
The Relationship

The determination of a prime mover’s characteristics is important in ascertaining its suitability for combined heat and power (CHP) applications. By definition, its operation affects the operation of all heat recovery equipment downstream. The correct balance between component electrical efficiency and waste heat is needed if the electric power producing equipment is to be used in a CHP application in a cost effective manner. Understanding the relationship between electric efficiency and exhaust stream energy content for different prime movers systems is a first step in an overall CHP system optimization. The goals of this work are to determine the potential financial benefit of utilizing waste heat from various prime mover configurations as well as establish the relationship between the two types of energy generation and costs. An economic optimization was performed to determine the system with the lowest average product (electricity and thermal energy) generation cost. The prime mover system was required to meet the electrical load demand of a typical 9290 m2 (100,000 ft2) office building in New York, NY, USA. The composition of the most cost effective prime mover system, when considering both electrical and thermal energy generation, was shown to be a single microturbine. When comparing the electrical and thermal energy generation of all systems studied with product generation cost, the more cost effective systems had either high electrical efficiency with a low thermal energy generation or high amounts of waste heat with low electrical efficiency. Each installation site and load demand is unique. The results of this study, along with others, can be used to help determine a cost effective system for a particular application.

Dynamic response of plant chlorophyll fluorescence to light, water and nutrient availability

2015 ◽  
Vol 42 (8) ◽  
pp. 746 ◽  
Author(s):  
M. Pilar Cendrero-Mateo ◽  
A. Elizabete Carmo-Silva ◽  
Albert Porcar-Castell ◽  
Erik P. Hamerlynck ◽  
Shirley A. Papuga ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Thermal Energy ◽  
Plant Stress ◽  
Nutrient Deficiency ◽  
Light Response ◽  
Response Curves ◽  
Light Response Curves ◽  
Thermal Energy Dissipation ◽  
Response To Water ◽  
The Relationship

Chlorophyll molecules absorb photosynthetic active radiation (PAR). The resulting excitation energy is dissipated by three competing pathways at the level of photosystem: (i) photochemistry (and, by extension, photosynthesis); (ii) regulated and constitutive thermal energy dissipation; and (iii) chlorophyll-a fluorescence (ChlF). Because the dynamics of photosynthesis modulate the regulated component of thermal energy dissipation (widely addressed as non-photochemical quenching (NPQ)), the relationship between photosynthesis, NPQ and ChlF changes with water, nutrient and light availability. In this study we characterised the relationship between photosynthesis, NPQ and ChlF when conducting light-response curves of photosynthesis in plants growing under different water, nutrient and ambient light conditions. Our goals were to test whether ChlF and photosynthesis correlate in response to water and nutrient deficiency, and determine the optimum PAR level at which the correlation is maximal. Concurrent gas exchange and ChlF light-response curves were measured for Camelina sativa (L.) Crantz and Triticum durum (L.) Desf plants grown under (i) intermediate light growth chamber conditions, and (ii) high light environment field conditions respectively. Plant stress was induced by withdrawing water in the chamber experiment, and applying different nitrogen levels in the field experiment. Our study demonstrated that ChlF was able to track the variations in photosynthetic capacity in both experiments, and that the light level at which plants were grown was optimum for detecting both water and nutrient deficiency with ChlF. The decrease in photosynthesis was found to modulate ChlF via different mechanisms depending on the treatment: through the action of NPQ in response to water stress, or through the action of changes in leaf chlorophyll concentration in response to nitrogen deficiency. This study provides support for the use of remotely sensed ChlF as a proxy to monitor plant stress dynamics from space.

An assessment of the relationship between embodied and thermal energy demands in dwellings in a Mediterranean climate

2015 ◽  
Vol 109 ◽  
pp. 230-244 ◽  
Author(s):  
Beatriz Rosselló-Batle ◽  
Carlos Ribas ◽  
Andreu Moià-Pol ◽  
Víctor Martínez-Moll
Keyword(s):  
Thermal Energy ◽  
Mediterranean Climate ◽  
Energy Demands ◽  
The Relationship

Considerations on Economic Optimization of the Relationship Insulation - Thermal Energy Sources Insurance for Civil Building

2014 ◽  
Vol 659 ◽  
pp. 463-468
Author(s):  
Adrian Alexandru Şerbănoiu ◽  
Gabriel Teodoriu ◽  
Bogdan Serbanoiu ◽  
Ion Serbanoiu ◽  
Marina Verdeș ◽  
...  
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Thermal Energy ◽  
Renewable Energy Sources ◽  
Building Envelope ◽  
Energy Sources ◽  
Economic Optimization ◽  
Major Objective ◽  
Financial Perspective ◽  
The Relationship

The major objective of this paper is to optimize the relationship insurance energy source - high thermal insulation of the building envelope analyzed in order to minimize the financial effort incurred by the beneficiary. In this respect, the paper proposes a methodology for analyzing the financial perspective of the relation envelope - equipment that capitalizes renewable energy sources, built on a newer concept - optimal cost.

scholarly journals Cost/Performance Analysis of Commercial-Grade Organic Phase-Change Materials for Low-Temperature Heat Storage

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Tomáš Hásl ◽  
Ivo Jiříček ◽  
Michal Jeremiáš ◽  
Josef Farták ◽  
Michael Pohořelý
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Thermal Capacity ◽  
Scanning Calorimetry ◽  
Cost Performance ◽  
Temperature Range ◽  
The Relationship

Alkanes are widely used as phase change materials (PCMs), especially for thermal energy storage (TES), due to their high thermal capacity, stability, availability, and non-corrosiveness. However, the drawbacks of alkanes are low heat conductivity and high cost. Our aim was to explore alternative organic PCMs for TES and to compare such compounds based on the relationship between their performance and cost. For this purpose, we analysed several commercially available products, including long chain alkanes, alcohols, monocarboxylic acid, amines, ethers and esters in high purities. Differential scanning calorimetry and thermogravimetry (DSC and TGA) were used to measure the melting point, melting enthalpy and thermal stability of these compounds. The materials were classified according to their melting temperature. In order to compare the compounds, we calculated from the measured enthalpies and the price list provided by producers a coefficient that represents factors in both the performance and cost of the material. This method was used to identify the most suitable organic compound for thermal energy storage in each temperature range. As the main result of this work, it has been revealed that various organic compounds can be considered as a vital alternative to the alkanes in temperatures from −10 to 50 °C. On top of that, alcohols and carboxylic acids can cover the temperature range from 50 to 75 °C, which cannot be covered by alkanes.

scholarly journals Organic Phase Change Materials for Thermal Energy Storage: Influence of Molecular Structure on Properties

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6635
Author(s):  
Samer Kahwaji ◽  
Mary Anne White
Keyword(s):  
Molecular Structure ◽  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Lower Cost ◽  
Alkyl Chains ◽  
Melting Temperatures ◽  
Wide Range ◽  
Efficient Packing ◽  
The Relationship

Materials that change phase (e.g., via melting) can store thermal energy with energy densities comparable to batteries. Phase change materials will play an increasing role in reduction of greenhouse gas emissions, by scavenging thermal energy for later use. Therefore, it is useful to have summaries of phase change properties over a wide range of materials. In the present work, we review the relationship between molecular structure and trends in relevant phase change properties (melting temperature, and gravimetric enthalpy of fusion) for about 200 organic compounds from several chemical families, namely alkanes (paraffins), fatty acids, fatty alcohols, esters, diamines, dinitriles, diols, dioic acids, and diamides. We also review availability and cost, chemical compatibility, and thermal and chemical stabilities, to provide practical information for PCM selection. Compounds with even chain alkyl lengths generally give higher melting temperatures, store more thermal energy per unit mass due to more efficient packing, and are of lower cost than the comparable compounds with odd alkyl chains.

Reflections on the Motive Power of Heat II

2010 ◽  
Author(s):  
George J. Mahl
Keyword(s):  
Thermal Energy ◽  
Mechanical Energy ◽  
Second Law Of Thermodynamics ◽  
Electrical Energy ◽  
Rankine Cycle ◽  
Second Law ◽  
Carnot Cycle ◽  
Original Analysis ◽  
Underlying Basis ◽  
The Relationship

This paper explores and challenges the underlying basis of the Second Law of Thermodynamics. The second law of thermodynamics and its related equations define the relationship between thermal energy and its conversion into mechanical work. The second law of thermodynamics and its equations are based on theory developed by analysis of the Carnot cycle, then with a leap of faith, applies this theory and these equations to the Rankine cycle and to the general conversion of thermal energy into mechanical energy. This paper explores the original analysis, which forms the basis of the second law of thermodynamics, and offers new analysis which may form a new understanding of thermodynamics. If proven correct, this new understanding may unlock tremendous resources for the production of mechanical and electrical energy.

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