Experimental Evaluation of Dewar Volume and Cryocooler Cold Finger Size in a Small-Scale Stirling Liquid Air Energy Storage (LAES) System

2021 ◽  
Author(s):  
Howard M. Swanson ◽  
Anthony G. Pollman ◽  
Alejandro Hernandez
Keyword(s):  
Energy Storage ◽  
Production Rate ◽  
Surface Area ◽  
Experimental Approach ◽  
Small Scale ◽  
Cold Finger ◽  
Average Production ◽  
Design Characteristics ◽  
Design Tradeoffs ◽  
Insight Into

Abstract This paper uses an experimental approach to evaluate two design characteristics for a liquid air energy storage (LAES) and generation system as part of the design analysis for a microgrid power system. The system evaluated utilized a Stirling engine based cryocooler that employs a coldfinger placed into a Dewar. Using a design of experiments, the cold finger surface area and Dewar volume were evaluated to determine the criticality and significance of changing their dimensions. Evaluations were made against the total liquid air production mass and average liquid air production rate during the experiments. This analysis found that changing the surface area of the cryocooler cold finger was a statistically significant design characteristic that affected total liquid air production and average production rate while changing the volume of the Dewar was not statistically significant. Additional responses relative to the time when the first gram of liquid air was produced and the minimum cold tip temperature that the cryocooler was able to achieve provided additional insight into design characteristics that can be used to inform the engineer when making design tradeoffs for specific operational environments.

Synthesis of high surface area and functionalized nanoporous biocarbons and their efficiency for CO2 capture and supercapacitors

2021 ◽  
Author(s):  
Gurwinder Singh ◽  
Rohan Bahadur ◽  
Ajanya Maria Ruban ◽  
Jefrin Marykala Davidraj ◽  
Dawei Su ◽  
...  
Keyword(s):  
Energy Storage ◽  
Surface Area ◽  
Co2 Capture ◽  
Water Purification ◽  
High Surface ◽  
High Surface Area ◽  
Energy Storage And Conversion ◽  
Waste Biomass ◽  
Fabrication Technology ◽  
Significant Attention

Nanoporous biocarbons derived from waste biomass have created significant attention owing to their great potential for energy storage and conversion and water purification. However, the fabrication technology for these materials...

scholarly journals Precise regulation of the relative rates of surface area and volume synthesis in bacterial cells growing in dynamic environments

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Handuo Shi ◽  
Yan Hu ◽  
Pascal D. Odermatt ◽  
Carlos G. Gonzalez ◽  
Lichao Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Time Delay ◽  
Surface Area ◽  
Environmental Changes ◽  
Volume Ratio ◽  
Dynamic Environments ◽  
Bacterial Cells ◽  
Bacterial Growth Rate ◽  
State Size ◽  
Insight Into

AbstractThe steady-state size of bacterial cells correlates with nutrient-determined growth rate. Here, we explore how rod-shaped bacterial cells regulate their morphology during rapid environmental changes. We quantify cellular dimensions throughout passage cycles of stationary-phase cells diluted into fresh medium and grown back to saturation. We find that cells exhibit characteristic dynamics in surface area to volume ratio (SA/V), which are conserved across genetic and chemical perturbations as well as across species and growth temperatures. A mathematical model with a single fitting parameter (the time delay between surface and volume synthesis) is quantitatively consistent with our SA/V experimental observations. The model supports that this time delay is due to differential expression of volume and surface-related genes, and that the first division after dilution occurs at a tightly controlled SA/V. Our minimal model thus provides insight into the connections between bacterial growth rate and cell shape in dynamic environments.

scholarly journals Valorization of Waste Tires by Pyrolysis and Activation Processes

2021 ◽  
Vol 11 (14) ◽  
pp. 6342
Author(s):  
Reyna Berenice González-González ◽  
Nadia Ruiz-Gómez ◽  
Gloria Gea ◽  
Matias Vazquez-Pinon ◽  
Sergio O. Martinez-Chapa ◽  
...  
Keyword(s):  
Energy Storage ◽  
Pore Size ◽  
Surface Area ◽  
Liquid Fraction ◽  
Average Pore Size ◽  
Chemical Activation ◽  
Partial Substitution ◽  
Physical Activation ◽  
Waste Tires ◽  
Energy Storage Applications

The problems related to the increase in the generation of discarded tires demonstrate the need for profitable, efficient, cost-effective, and sustainable processes for their waste management. In particular, the valorization of pyrolytic solids for energy storage applications is of interest. In this study, four processes were performed: (1) pyrolysis; (2) chemical activation and pyrolysis; (3) pyrolysis and physical activation; and (4) chemical activation, pyrolysis, and physical activation. The process consisting of chemical activation, pyrolysis, and physical activation yielded 52% solid material with the highest electrical conductivity (2.43 Ω–1 cm–1) and a surface area of 339 m2/g with an average pore size of 3.6 nm. In addition, it was found that pore size had a greater effect on the conductivity than surface area. Liquid and gas fraction compositions were modified by the presence of chemical activation: aromatization reactions were favored, and limonene was not observed in the liquid fraction, while an increase on the CH4 concentration caused an increment in the heating value of the gas fraction. It was demonstrated that chemical and physical activation enhance the properties of the pyrolytic solid product derived from waste tires that make it suitable for the partial substitution of materials for electric energy storage applications.

scholarly journals Effect of infrastructure design on commons dilemmas in social−ecological system dynamics

2015 ◽  
Vol 112 (43) ◽  
pp. 13207-13212 ◽  
Author(s):  
David J. Yu ◽  
Murad R. Qubbaj ◽  
Rachata Muneepeerakul ◽  
John M. Anderies ◽  
Rimjhim M. Aggarwal
Keyword(s):  
Design Feature ◽  
Irrigated Agriculture ◽  
Small Scale ◽  
Qualitative Behavior ◽  
Central Feature ◽  
Social Ecological ◽  
Vital Functions ◽  
The Face ◽  
Design Characteristics ◽  
Shared Infrastructure

The use of shared infrastructure to direct natural processes for the benefit of humans has been a central feature of human social organization for millennia. Today, more than ever, people interact with one another and the environment through shared human-made infrastructure (the Internet, transportation, the energy grid, etc.). However, there has been relatively little work on how the design characteristics of shared infrastructure affect the dynamics of social−ecological systems (SESs) and the capacity of groups to solve social dilemmas associated with its provision. Developing such understanding is especially important in the context of global change where design criteria must consider how specific aspects of infrastructure affect the capacity of SESs to maintain vital functions in the face of shocks. Using small-scale irrigated agriculture (the most ancient and ubiquitous example of public infrastructure systems) as a model system, we show that two design features related to scale and the structure of benefit flows can induce fundamental changes in qualitative behavior, i.e., regime shifts. By relating the required maintenance threshold (a design feature related to infrastructure scale) to the incentives facing users under different regimes, our work also provides some general guidance on determinants of robustness of SESs under globalization-related stresses.

scholarly journals Charting the Rough Journey to ‘Home’: The Contribution of Qualitative Longitudinal Research to Understandings of Homelessness in Austerity

2021 ◽  
pp. 1-17
Author(s):  
Emma Davidson ◽  
Briege Nugent ◽  
Sarah Johnsen
Keyword(s):  
Longitudinal Research ◽  
Support Service ◽  
Added Value ◽  
Small Scale ◽  
Deep Insight ◽  
Policy Makers ◽  
Analytical Potential ◽  
Longitudinal Approach ◽  
The Uk ◽  
Insight Into

This article reflects on the contribution of qualitative longitudinal research (QLR) to understandings of homeless peoples’ experiences of support service interventions in an era of austerity in the UK. It brings into ‘analytic conversation’ data from qualitative longitudinal evaluations of homeless support projects operated by voluntary sector organisations in Scotland. With fieldwork spanning 2014-2019, the analysis expands the analytical potential of pooling small-scale studies through an interrogation of individuals’ ‘journeys’ through homelessness services and their rough path to ‘home’. By reflecting on our substantive findings, the article explores the added value and challenges of a longitudinal approach. It concludes that while QLR can deliver deep insight into lives lived by vulnerable populations and potentially reduce the distance between policy makers and those affected, its benefits must be balanced against pragmatism and the ethical responsibilities associated with the method.

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