scholarly journals Enhanced Reactant Distribution in Redox Flow Cells

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3877 ◽  
Author(s):  
Nicholas Gurieff ◽  
Declan Finn Keogh ◽  
Victoria Timchenko ◽  
Chris Menictas
Keyword(s):  
Power Density ◽  
Effective Means ◽  
Cell Voltage ◽  
Cost Effective ◽  
Vanadium Redox Flow Battery ◽  
Limiting Current ◽  
Concentration Gradients ◽  
Static Mixers ◽  
A Cell ◽  
Reactant Distribution

Redox flow batteries (RFBs), provide a safe and cost-effective means of storing energy at grid-scale, and will play an important role in the decarbonization of global electricity networks. Several approaches have been explored to improve their efficiency and power density, and recently, cell geometry modification has shown promise in efforts to address mass transport limitations which affect electrochemical and overall system performance. Flow-by electrode configurations have demonstrated significant power density improvements in laboratory testing, however, flow-through designs with conductive felt remain the standard at commercial scale. Concentration gradients exist within these cells, limiting their performance. A new concept of redistributing reactants within the flow frame is introduced in this paper. This research shows a 60% improvement in minimum V3+ concentration within simulated vanadium redox flow battery (VRB/VRFB) cells through the application of static mixers. The enhanced reactant distribution showed a cell voltage improvement by reducing concentration overpotential, suggesting a pathway forward to increase limiting current density and cycle efficiencies in RFBs.

scholarly journals Variable Porous Electrode Compression for Redox Flow Battery Systems

Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 53 ◽  
Author(s):  
Nicholas Gurieff ◽  
Victoria Timchenko ◽  
Chris Menictas
Keyword(s):  
Large Scale ◽  
Effective Means ◽  
Porous Electrode ◽  
Cost Effective ◽  
Electrical Energy ◽  
Limiting Current ◽  
Great Promise ◽  
Full Potential ◽  
Uniform Compression ◽  
Novel Concept

Vanadium redox flow batteries (VRFBs) offer great promise as a safe, cost effective means of storing electrical energy on a large scale and will certainly have a part to play in the global transition to renewable energy. To unlock the full potential of VRFB systems, however, it is necessary to improve their power density. Unconventional stack design shows encouraging possibilities as a means to that end. Presented here is the novel concept of variable porous electrode compression, which simulations have shown to deliver a one third increase in minimum limiting current density together with a lower pressure drop when compared to standard uniform compression cell designs.

scholarly journals RNA-seq: primary cells, cell lines and heat stress

2015 ◽  
Author(s):  
Carl J Schmdt ◽  
Elizabeth M Pritchett ◽  
Liang Sun ◽  
Richard V.N. Davis ◽  
Allen Hubbard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Sequence Data ◽  
Expression Patterns ◽  
Effective Means ◽  
Cost Effective ◽  
Rna Seq ◽  
Individual Gene ◽  
Examine Gene Expression ◽  
A Cell

Transcriptome analysis by RNA-seq has emerged as a high-throughput, cost-effective means to evaluate the expression pattern of genes in organisms. Unlike other methods, such as microarrays or quantitative PCR, RNA-seq is a target free method that permits analysis of essentially any RNA that can be amplified from a cell or tissue. At its most basic, RNA-seq can determine individual gene expression levels by counting the number of times a particular transcript was found in the sequence data. Transcript levels can be compared across multiple samples to identify differentially expressed genes and infer differences in biological states between the samples. We have used this approach to examine gene expression patterns in chicken and human cells, with particular interest in determining response to heat stress.

scholarly journals A tubular electrochemical reactor for slurry electrodes

2020 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Power Density ◽  
Current Density ◽  
Volume Ratio ◽  
Electrochemical Reactor ◽  
Vanadium Redox Flow Battery ◽  
Redox Flow Battery ◽  
Electrochemical Reactors ◽  
Static Mixers ◽  
Particle Mixing ◽  
Vanadium Redox

The research on electrochemical reactors is mostly limited to planarly designedmodules. In this study, we compare a tubular and a planar electrochemicalreactor for the utilization of the slurry electrodes. Cylindrical formed geometriesdemonstrate a higher surface-to-volume ratio, which may be favorable interms of current density and volumetric power density. A tubular shaped electrochemical reactor is designed with conductive static mixers to promote theslurry particle mixing, and the vanadium redox flow battery is selected as ashowcase application. The new tubular design presents similar cell resistancesto the previously designed planar battery and shows increased discharge polarization behavior up to 100mAcm-2. The volumetric power density reaches upto 30mWcm-3, which is two times higher than that of the planar one. The battery performance is further investigated and 85% coulombic, 70% voltage and 60% energy effciency is found at 15mAcm-2 with 15 wt.% slurry content.

Parallel Computing for Tire Simulations

2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar
Keyword(s):  
High Performance ◽  
Effective Means ◽  
Cost Effective ◽  
Turnaround Time ◽  
Careful Consideration ◽  
Rolling Contact ◽  
Element Analysis ◽  
Parallel Solvers ◽  
Design Changes ◽  
Highly Nonlinear

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.

Exploring the Benefits of Early Contractor Involvement (ECI) and the Mechanism for Automated 5D BIM Quantification Process in Offsite Modular Construction

2016 ◽  
Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Modular Construction ◽  
Automated Quantification ◽  
Building Information ◽  
Project Risks ◽  
Value Add ◽  
The Uk ◽  
The Impact ◽  
Level 2

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.

scholarly journals mRNA-Based Vaccines

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 390
Author(s):  
Frank Kowalzik ◽  
Daniel Schreiner ◽  
Christian Jensen ◽  
Daniel Teschner ◽  
Stephan Gehring ◽  
...  
Keyword(s):  
Large Scale ◽  
New Technologies ◽  
Vaccine Development ◽  
Effective Means ◽  
Cost Effective ◽  
Clinical Applications ◽  
Cell Mediated Immunity ◽  
Healthy Individuals ◽  
Emerging Pathogens ◽  
Cell Genome

Increases in the world’s population and population density promote the spread of emerging pathogens. Vaccines are the most cost-effective means of preventing this spread. Traditional methods used to identify and produce new vaccines are not adequate, in most instances, to ensure global protection. New technologies are urgently needed to expedite large scale vaccine development. mRNA-based vaccines promise to meet this need. mRNA-based vaccines exhibit a number of potential advantages relative to conventional vaccines, namely they (1) involve neither infectious elements nor a risk of stable integration into the host cell genome; (2) generate humoral and cell-mediated immunity; (3) are well-tolerated by healthy individuals; and (4) are less expensive and produced more rapidly by processes that are readily standardized and scaled-up, improving responsiveness to large emerging outbreaks. Multiple mRNA vaccine platforms have demonstrated efficacy in preventing infectious diseases and treating several types of cancers in humans as well as animal models. This review describes the factors that contribute to maximizing the production of effective mRNA vaccine transcripts and delivery systems, and the clinical applications are discussed in detail.

scholarly journals Sporulation in solventogenic and acetogenic clostridia

2021 ◽  
Author(s):  
Mamou Diallo ◽  
Servé W. M. Kengen ◽  
Ana M. López-Contreras
Keyword(s):  
Current Knowledge ◽  
Carbon Sources ◽  
Cost Effective ◽  
Biotechnological Production ◽  
Key Points ◽  
Wide Range ◽  
Potential Applications ◽  
A Cell ◽  
Sporulation Initiation ◽  
Solventogenic Clostridia

AbstractThe Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.

A method for correcting acoustic finite-difference amplitudes for elastic effects

Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. T243-T255 ◽  
Author(s):  
James W. D. Hobro ◽  
Chris H. Chapman ◽  
Johan O. A. Robertsson
Keyword(s):  
Wave Equation ◽  
Finite Difference ◽  
Effective Means ◽  
Cost Effective ◽  
P Wave ◽  
S Waves ◽  
Velocity Models ◽  
Acoustic Simulation ◽  
Wide Range ◽  
Elastic Simulation

We present a new method for correcting the amplitudes of arrivals in an acoustic finite-difference simulation for elastic effects. In this method, we selectively compute an estimate of the error incurred when the acoustic wave equation is used to approximate the behavior of the elastic wave equation. This error estimate is used to generate an effective source field in a second acoustic simulation. The result of this second simulation is then applied as a correction to the original acoustic simulation. The overall cost is approximately twice that of an acoustic simulation but substantially less than the cost of an elastic simulation. Because both simulations are acoustic, no S-waves are generated, so dispersed converted waves are avoided. We tested the characteristics of the method on a simple synthetic model designed to simulate propagation through a strong acoustic impedance contrast representative of sedimentary geology. It corrected amplitudes to high accuracy for reflected arrivals over a wide range of incidence angles. We also evaluated results from simulations on more complex models that demonstrated that the method was applicable in realistic sedimentary models containing a wide range of seismic contrasts. However, its accuracy was reduced for wide-angle reflections from very high impedance contrasts such as a shallow top-salt interface. We examined the influence of modeling at coarse grid resolutions, in which converted S-waves in the equivalent elastic simulation are dispersed. These results provide some validation for the accuracy of the method when applied using finite-difference grids designed for acoustic modeling. The method appears to offer a cost-effective means of modeling elastic amplitudes for P-wave arrivals in a useful range of velocity models. It has several potential applications in imaging and inversion.

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