scholarly journals Performance Indicators for Benchmarking Solar Thermochemical Fuel Processes and Reactors

2021 ◽  
Vol 9 ◽  
Author(s):  
Brendan Bulfin ◽  
Miguel Miranda ◽  
Aldo Steinfeld
Keyword(s):  
Energy Efficiency ◽  
Performance Indicators ◽  
Performance Benchmarking ◽  
Concentrated Solar Energy ◽  
Modelling Studies ◽  
Thermochemical Processes ◽  
Efficiency Conversion ◽  
Solar Reactors ◽  
And Performance ◽  
Reacting Systems

Concentrated solar energy offers a source for renewable high-temperature process heat that can be used to efficiently drive endothermic chemical processes, converting the entire spectrum of solar radiation into chemical energy. In particular, solar-driven thermochemical processes for the production of fuels include reforming of methane and other hydrocarbons, gasification of biomass, coal, and other carbonaceous feedstock, and metal oxide redox cycles for splitting H2O and CO2. A notable issue in the development of these processes and their associated solar reactors is the lack of consistent reporting methods for experimental demonstrations and modelling studies, which complicates the benchmarking of the corresponding technologies. In this work we formulate dimensionless performance indicators based on mass and energy balances of such reacting systems, namely: energy efficiency, conversion extent, selectivity, and yield. Examples are outlined for the generic processes mention above. We then provide guidelines for reporting on such processes and reactors and suggest performance benchmarking on four key criteria: energy efficiency, conversion extent, product selectivity, and performance stability.

On the Influence of Fluctuating Flow Rate Upon the Performance and Behaviour of Isothermal Reacting Systems

1998 ◽  
Vol 63 (6) ◽  
pp. 881-898
Author(s):  
Otakar Trnka ◽  
Miloslav Hartman
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Fluidized Bed Reactor ◽  
Computational Techniques ◽  
Continuous Stirred Tank Reactor ◽  
Gas Flow Rate ◽  
Solid Reaction ◽  
Continuous Stirred Tank ◽  
And Performance ◽  
Reacting Systems

Three simple computational techniques are proposed and employed to demonstrate the effect of fluctuating flow rate of feed on the behaviour and performance of an isothermal, continuous stirred tank reactor (CSTR). A fluidized bed reactor (FBR), in which a non-catalytic gas-solid reaction occurs, is also considered. The influence of amplitude and frequency of gas flow rate fluctuations on reactant concentrations at the exit of the CSTR is shown in four different situations.

scholarly journals Power and Performance Evaluation of Memory-Intensive Applications

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4089
Author(s):  
Kaiqiang Zhang ◽  
Dongyang Ou ◽  
Congfeng Jiang ◽  
Yeliang Qiu ◽  
Longchuan Yan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Power Consumption ◽  
Job Scheduling ◽  
Memory System ◽  
Processor Core ◽  
Memory Efficiency ◽  
And Performance ◽  
Reasonable Use ◽  
Server System

In terms of power and energy consumption, DRAMs play a key role in a modern server system as well as processors. Although power-aware scheduling is based on the proportion of energy between DRAM and other components, when running memory-intensive applications, the energy consumption of the whole server system will be significantly affected by the non-energy proportion of DRAM. Furthermore, modern servers usually use NUMA architecture to replace the original SMP architecture to increase its memory bandwidth. It is of great significance to study the energy efficiency of these two different memory architectures. Therefore, in order to explore the power consumption characteristics of servers under memory-intensive workload, this paper evaluates the power consumption and performance of memory-intensive applications in different generations of real rack servers. Through analysis, we find that: (1) Workload intensity and concurrent execution threads affects server power consumption, but a fully utilized memory system may not necessarily bring good energy efficiency indicators. (2) Even if the memory system is not fully utilized, the memory capacity of each processor core has a significant impact on application performance and server power consumption. (3) When running memory-intensive applications, memory utilization is not always a good indicator of server power consumption. (4) The reasonable use of the NUMA architecture will improve the memory energy efficiency significantly. The experimental results show that reasonable use of NUMA architecture can improve memory efficiency by 16% compared with SMP architecture, while unreasonable use of NUMA architecture reduces memory efficiency by 13%. The findings we present in this paper provide useful insights and guidance for system designers and data center operators to help them in energy-efficiency-aware job scheduling and energy conservation.

scholarly journals Comparative analysis of models and performance indicators for optimal service facility location

2021 ◽  
Vol 145 ◽  
pp. 102174
Author(s):  
Edoardo Fadda ◽  
Daniele Manerba ◽  
Gianpiero Cabodi ◽  
Paolo Enrico Camurati ◽  
Roberto Tadei
Keyword(s):  
Comparative Analysis ◽  
Facility Location ◽  
Performance Indicators ◽  
Service Facility ◽  
Optimal Service ◽  
And Performance

Twenty Years After the Hype

2015 ◽  
Vol 2 (2) ◽  
pp. 1-21 ◽  
Author(s):  
Alois Paulin
Keyword(s):  
Performance Indicators ◽  
The State ◽  
Government Performance ◽  
Before And After ◽  
To Come ◽  
And Performance ◽  
Government Reforms

In this study the authors analyze the effects of e-government reforms that began in mid-90ies by confronting the promises which these reforms made to government performance in the period before and after the reforms took place. The authors use fiscal and performance indicators of the Slovenian government and courts to argue that e-government did not yield any notable effects on the state performance. Finally, the authors analyze the reasons why e-government technology cannot be regarded as sustainable and suggest a different approach towards researching how to sustainably improve governance for generations to come.

Methodology for analyzing PR activities of public authorities

2021 ◽  
Vol 23 (3) ◽  
pp. 33-38
Author(s):  
VALERYA DAMBUEVA ◽  
Keyword(s):  
Performance Indicators ◽  
Mass Communication ◽  
Public Authorities ◽  
Analysis And Evaluation ◽  
Complex Image ◽  
The Russian Federation ◽  
And Performance ◽  
Commercial Organizations ◽  
Analytical Tools ◽  
Evaluation Parameters

The article analyses various approaches to assessing the PR activities of commercial organizations and public authorities. The author concludes that there is no comprehensive methodology for analyzing and evaluating the effectiveness of PR activities. This indicates the relevance and the need to develop a special methodology to identify relevant and potential sources for the formation and development of a complex image and reputation characteristics of public authorities with which citizens of the Russian Federation could operate. The basis of the proposed theory is the materials of works on communication by G. Lasswell (model of mass communication, pentad). The method is a system of evaluation parameters, performance indicators, and analytical tools for each structural component of such activities, as well as an algorithm for their analysis and evaluation. When developing this methodology, we try to take into account the maximum number of criteria and performance indicators, but in practice, it is not always possible. To increase the effectiveness of the methodology, the author conducts the structuring of the pentad, which allows to distinguish the main processes of PR activity of a public authority. The assessment of each component of the pentad is a separate study in which we can identify the relevant PR activity processes that require adjustment.

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