scholarly journals Enzymatic Biofuel Cells: A Review on Flow Designs

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 910
Author(s):  
Linda Barelli ◽  
Gianni Bidini ◽  
Dario Pelosi ◽  
Elena Sisani
Keyword(s):  
Power Output ◽  
Wearable Devices ◽  
Operating Conditions ◽  
Biofuel Cells ◽  
Term Stability ◽  
Long Term Stability ◽  
Stage Of Development ◽  
Enzymatic Biofuel Cells ◽  
Wide Range

Because of environmental concerns, there is a growing interest in new ways to produce green energy. Among the several studied applications, enzymatic biofuel cells can be considered as a promising solution to generate electricity from biological catalytic reactions. Indeed, enzymes show very good results as biocatalysts thanks to their excellent intrinsic properties, such as specificity toward substrate, high catalytic activity with low overvoltage for substrate conversion, mild operating conditions like ambient temperature and near-neutral pH. Furthermore, enzymes present low cost, renewability and biodegradability. The wide range of applications moves from miniaturized portable electronic equipment and sensors to integrated lab-on-chip power supplies, advanced in vivo diagnostic medical devices to wearable devices. Nevertheless, enzymatic biofuel cells show great concerns in terms of long-term stability and high power output nowadays, highlighting that this particular technology is still at early stage of development. The main aim of this review concerns the performance assessment of enzymatic biofuel cells based on flow designs, considered to be of great interest for powering biosensors and wearable devices. Different enzymatic flow cell designs are presented and analyzed highlighting the achieved performances in terms of power output and long-term stability and emphasizing new promising fabrication methods both for electrodes and cells.

scholarly journals Long-Term Stability of Ferroelectret Energy Harvesters

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 42 ◽  
Author(s):  
Muhammed Kayaharman ◽  
Taylan Das ◽  
Gregory Seviora ◽  
Resul Saritas ◽  
Eihab Abdel-Rahman ◽  
...  
Keyword(s):  
Output Power ◽  
Operating Conditions ◽  
Constant Stress ◽  
Center Frequency ◽  
Term Stability ◽  
Energy Harvesters ◽  
Long Term Stability ◽  
Stress Cycling ◽  
Piezoelectric Charge

Cellular polypropylene (PP) has been recently used in energy harvesting applications. In this work, we investigate its viability and long-term stability under various operating conditions. Specifically, the effect of constant stress and stress cycling on output power and long-term stability of ferroelectret energy harvesters is analyzed. Our findings show that after 112 days constant stress significantly increases the piezoelectric charge constant d 33 and output power from 0.51 μW for a stress-free harvester to 2.71 μW. It also increases the harvester center frequency from 450 to 700 Hz and decreases its optimal resistance from 7 to 5.5 M Ω .

scholarly journals Experimental Devices to Investigate the Long-Term Stability of Phase Change Materials under Application Conditions

2020 ◽  
Vol 10 (22) ◽  
pp. 7968
Author(s):  
Christoph Rathgeber ◽  
Stefan Hiebler ◽  
Rocío Bayón ◽  
Luisa F. Cabeza ◽  
Gabriel Zsembinszki ◽  
...  
Keyword(s):  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Term Stability ◽  
Long Term Stability ◽  
Wide Range ◽  
Solidification Processes ◽  
The Stability ◽  
Solid Liquid

An important prerequisite to select a reliable phase change material (PCM) for thermal energy storage applications is to test it under application conditions. In the case of solid–liquid PCM, a large amount of thermal energy can be stored and released in a small temperature range around the solid–liquid phase transition. Therefore, to test the long-term stability of solid–liquid PCM, they are subjected to melting and solidification processes taking into account the conditions of the intended application. In this work, 18 experimental devices to investigate the long-term stability of PCM are presented. The experiments can be divided into thermal cycling stability tests, tests on PCM with stable supercooling, and tests on the stability of phase change slurries (PCS). In addition to these experiments, appropriate methods to investigate a possible degradation of the PCM are introduced. Considering the diversity of the investigated devices and the wide range of experimental parameters, further work toward a standardization of PCM stability testing is recommended.

scholarly journals Curcumin Containing PEGylated Solid Lipid Nanoparticles for Systemic Administration: A Preliminary Study

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 2991 ◽  
Author(s):  
Debora Santonocito ◽  
Maria Grazia Sarpietro ◽  
Claudia Carbone ◽  
Annamaria Panico ◽  
Agata Campisi ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Solid Lipid Nanoparticles ◽  
Antioxidant Activities ◽  
Lipid Nanoparticles ◽  
Systemic Administration ◽  
Term Stability ◽  
Long Term Stability ◽  
Solid Lipid ◽  
Wide Range

Curcumin (CUR) has a wide range of pharmacological properties, including anti-inflammatory and antioxidant activities, and it can be considered a good candidate for the potential treatment of central nervous system (CNS) pathologies, although its use in clinical practice is compromised due to its high lipophilicity. Solid lipid nanoparticles (SLNs) are well-known nanocarriers representing a consolidated approach for the delivery of lipophilic compounds, but their systemic use is limited due their short half-life. The formulation of stealth SLNs (pSLNs) could be a valid strategy to overcome this limit. Curcumin-loaded-pSLNs were prepared by the solvent evaporation method. Formulation was characterized for their mean size, zeta potential, size distribution, and morphology. Drug antioxidant activity was evaluated by Oxygen Radical Absorbance Capacity (ORAC) assay. Finally, the obtained formulations were analyzed in terms of long-term stability. Curcumin-loaded-pSLNs showed good technological parameters with a mean particle size below 200 nm, as confirmed by TEM images, and a zeta potential value around −30 mV, predicting good long-term stability. Differential Scanning Calorimetry (DSC) analysis confirmed that PEG micelles interacted with the SLN surface; this suggests the location of the PEG on the pSLN surface. Therefore, these preliminary studies suggest that the produced formulation could be regarded as a promising carrier for the systemic administration.

An acquisitional approach to disharmonic word-order/affixation pairings

2004 ◽  
Vol 2 ◽  
pp. 31-71 ◽  
Author(s):  
Michael Fortescue ◽  
J. Lachlan Mackenzie
Keyword(s):  
Word Order ◽  
A Priori ◽  
Developmental Approach ◽  
Term Stability ◽  
Long Term Stability ◽  
Stage Of Development

Various proposals have been put forward to explain the typological skewing produced by the universal preference for suffixing as opposed to prefixing. These proposals have focused either on processing or on diachronic explanations (or a combination of both). In the present paper it is argued that a developmental approach is more comprehensive than either of these. It can explain exceptions from typologically universal tendencies as well as the tendencies themselves in terms of alternative ways of balancing off basic acquisitional principles involved already at the holophrastic stage of development. The long-term stability of certaina priori‘disharmonic’ or unusual combinations of features is emphasised. What is needed to give support to the model is data from the acquisition of languages with rich morphologies. The available data is examined for evidence and a framework is proposed as a guide to future investigations.

Accelerated Degradation for Hardware in the Loop Simulation of Fuel Cell-Gas Turbine Hybrid

2014 ◽  
Author(s):  
Maria Abreu-Sepulveda ◽  
David Tucker ◽  
Nor Farida Harun ◽  
Gregory Hackett ◽  
Anke Hagen
Keyword(s):  
Fuel Cell ◽  
Real Time ◽  
Gas Turbine ◽  
Degradation Rate ◽  
Operating Conditions ◽  
Hardware In The Loop ◽  
Electrochemical Degradation ◽  
Term Stability ◽  
Long Term Stability

Solid oxide fuel cells (SOFCs) are a promising technology for clean power generation, however their implementation has been limited by several degradation mechanisms, which significantly reduce its lifetime under constant output power and inhibits the technology for commercialization in the near future. With the purpose of harnessing the capabilities offered by SOFCs, the U.S. DOE-National Energy Technology Laboratory (NETL) in Morgantown, WV has developed the Hybrid Performance (HyPer) project in which a SOFC 1D, real-time operating model is coupled to a gas turbine hardware system by utilizing hardware-in-the-loop simulation (HiLS). More recently, in order to assess the long-term stability of the SOFC part of the system, electrochemical degradation due to operating conditions such as current density and fuel utilization have been incorporated into the SOFC model and successfully recreated in real time for standalone and hybrid operation. The mathematical expression for degradation rate was obtained through the analysis of empirical voltage versus time plots for different current densities and fuel utilizations at 750, 800, and 850°C. Simulation results well reflected the behavior of SOFC degradation rates from which the long-term stability of the cell under various conditions was assessed. Distributed fuel cell parameters are presented for both standalone and hybrid configurations. The incorporation of the electrochemical degradation rate into the SOFC model provides a framework to study more realistically Fuel Cell-hybrid systems and set forth a mechanism to improve the long-term stability of SOFCs through the hybridization of such technology.

scholarly journals Long-term stability of the final slopes of the mining waste dumps from Oltenia

2021 ◽  
Vol 342 ◽  
pp. 03005
Author(s):  
Maria Lazar ◽  
Florin Faur ◽  
Izabela-Maria Apostu ◽  
Constantin Rada
Keyword(s):  
Operating Conditions ◽  
Strength Characteristics ◽  
Design Stage ◽  
Term Stability ◽  
Long Term Stability ◽  
Influence Area ◽  
Waste Dumps ◽  
The Stability ◽  
The Moment

The waste dumps resulted from the lignite exploitation activities from Oltenia are constructions that reach, in most cases, impressive dimensions and store large volumes of sterile rocks. Usually, the dumps are arranged and ecologically restored, but between the moment of their release from technological tasks and the beginning of the arrangement works, periods of time, measured even in years, can pass. The calculations regarding the geometry of the waste dumps are performed in the design stage, taking into account the mechanical strength characteristics of the mixture of sterile material that forms them, so as to ensure a sufficient stability reserve during the construction period and when the projected storage capacity is achieved. If the arrangement and ecological restoration works do not start immediately after the depositing activity is stopped, the exposure of loose and disaggregated material to the influence of external factors (especially erosion and rainfall infiltration) can lead to landslides with disastrous consequences on natural and anthropogenic objectives located in the influence area. This paper analyzes the stability elements of waste dumps under normal operating conditions, the modification of the strength characteristics over time and the geometry required in the final phase so as to ensure their long-term stability.

scholarly journals Long-term stability of marine dissolved organic carbon emerges from a neutral network of compounds and microbes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Mentges ◽  
C. Feenders ◽  
C. Deutsch ◽  
B. Blasius ◽  
T. Dittmar
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Deep Sea ◽  
Mechanistic Model ◽  
Term Stability ◽  
Long Term Stability ◽  
Heterotrophic Microorganisms ◽  
Wide Range ◽  
The Mean

AbstractDissolved organic carbon (DOC) is the main energy source for marine heterotrophic microorganisms, but a small fraction of DOC resists microbial degradation and accumulates in the ocean. The reason behind this recalcitrance is unknown. We test whether the long-term stability of DOC requires the existence of structurally refractory molecules, using a mechanistic model comprising a diverse network of microbe-substrate interactions. Model experiments reproduce three salient observations, even when all DOC compounds are equally degradable: (i) >15% of an initial DOC pulse resists degradation, but is consumed by microbes if concentrated, (ii) the modelled deep-sea DOC reaches stable concentrations of 30–40 mmolC/m3, and (iii) the mean age of deep-sea DOC is several times the age of deep water with a wide range from <100 to >10,000 years. We conclude that while structurally-recalcitrant molecules exist, they are not required in the model to explain either the amount or longevity of DOC.

A New Design Paradigm for Smart Windows: Photocurable Polymers for Quasi-Solid Photoelectrochromic Devices with Excellent Long-Term Stability under Real Outdoor Operating Conditions

2015 ◽  
Vol 26 (7) ◽  
pp. 1127-1137 ◽  
Author(s):  
Federico Bella ◽  
George Leftheriotis ◽  
Gianmarco Griffini ◽  
George Syrrokostas ◽  
Stefano Turri ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Smart Windows ◽  
Term Stability ◽  
Long Term Stability ◽  
Design Paradigm
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