We introduce and study a new mathematical structure in the generalised (quantum) cohomology theory for Grassmannians. Namely, we relate the Schubert calculus to a quantum integrable system known in ...the physics literature as the asymmetric six-vertex model. Our approach offers a new perspective on already established and well-studied special cases, for example equivariant K-theory, and in addition allows us to formulate a conjecture on the so-far unknown case of quantum equivariant K-theory.
We propose a new approach to studying electrical networks interpreting the Ohm law as the operator which solves certain local Yang-Baxter equation. Using this operator and the medial graph of the ...electrical network we define a vertex integrable statistical model and its boundary partition function. This gives an equivalent description of electrical networks. We show that, in the important case of an electrical network on the standard graph introduced in Curtis E B et al 1998 Linear Algebr. Appl. 283 115-50, the response matrix of an electrical network, its most important feature, and the boundary partition function of our statistical model can be recovered from each other. Defining the electrical varieties in the usual way we compare them to the theory of the Lusztig varieties developed in Berenstein A et al 1996 Adv. Math. 122 49-149. In our picture the former turns out to be a deformation of the later. Our results should be compared to the earlier work started in Lam T and Pylyavskyy P 2015 Algebr. Number Theory 9 1401-18 on the connection between the Lusztig varieties and the electrical varieties. There the authors introduced a one-parameter family of Lie groups which are deformations of the unipotent group. For the value of the parameter equal to 1 the group in the family acts on the set of response matrices and is related to the symplectic group. Using the data of electrical networks we construct a representation of the group in this family which corresponds to the value of the parameter −1 in the symplectic group and show that our boundary partition functions belong to it. Remarkably this representation has been studied before in the work on six vertex statistical models and the representations of the Temperley-Lieb algebra.
The mitigation of climate change, abatement of greenhouse gas emissions and thus, fundamentally, the separation of CO2 from various gas streams are some of the most pressing and multifaceted issues ...that we face as a society. De-carbonising our entire civilisation will come at a great cost and requires vast amounts of knowledge, initiative and innovation; yet, no matter how much time or money is spent, some sectors simply cannot be de-carbonised without the deployment of carbon capture and storage technologies. The technical challenges associated with the removal of CO2 are not universal – there exists no single solution. Capturing the CO2 on solid sorbents has been gaining traction in recent years given its cost-effectiveness as a result of its ease of application, relatively small energy requirements and applicability in a wide range of processes. Even with the myriad materials such as zeolites, carbons, metal organic frameworks, mesoporous silicas and polymers, the challenge to identify a sorbent with optimal capacity, kinetics, selectivity, stability and ultimately, viability, still persists. By tailoring these solid materials through comprehensive campaigns of surface modification, the pitfalls of each can be mollified and the strengths enhanced. This highly specific tailoring must be well informed so as to understand the mechanisms by which the CO2 is adsorbed, the surface chemistry that has influence on this process, and what methods exist to facilitate the improvement of this. This review endeavours to identify the surface functional groups that interact with the CO2 molecules during adsorption and the methods by which these functional groups can be introduced. It also provides a comprehensive review of the recent attempts and advancements made within the scientific community in the experimental applications of such methods to enhance CO2 capture via adsorption processes. The primary search engine employed in this critical review was Scopus. Of the 421 references cited that embody the literature focussed on surface modification for enhancing the selective adsorption of CO2, 370 are original research papers, 43 are review articles and 7 are conference proceedings.
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•Critical review of surface modification methods employed to enhance CO2 adsorption.•Assessment of CO2 adsorption mechanisms in the context of surface functional groups.•Evaluation of the methods used to introduce functional groups on adsorbent surfaces.•Critical discussion of the reagents used in surface modification of adsorbents.
Abstract Artificial neural networks emerged in the early 1940s as a connectionist approach to modeling the behavior of interconnected living nerve cells within the intricate cognitive framework of ...the brain. Over the years, this idea has undergone unprecedented proliferation of ever-expanding application areas, accompanied by an exponential surge in the mathematical formalism employed. This prodigious growth poses severe demands on computational hardware infrastructure. The current research suggests a novel approach for optimizing artificial neural network architectures using resource-sharing techniques. It is discussed the concept of merging context-switching and time-division multiplexing in building a single-neuron artificial neural network with the aid of an FPGA device. This would benefit the significant reduction of hardware resources and the possibility of creating small yet very efficient artificial neural networks without deteriorating the dynamical system performance.
•Thermo-chemical treatments produce surface functionalities to enhance CO2 adsorption;•Critical evaluation of the interactions between surface functionalities and CO2;•Discussion of the role moisture ...plays in CO2 adsorption on surface modified carbons; and•Novel applications of artificial intelligence and molecular simulations in carbon capture.
The utilisation of solid adsorbents for the selective removal of CO2 from major emission points is an attractive method for post-combustion carbon capture due to the inherent potential for retrofit and cost-effectiveness. Although focus in the scientific community is often centred on extremely novel, high-performance and costly material development, the exploitation of carbonaceous adsorbents is another avenue of research proving to be extremely promising. This is even more pronounced when considering the abundance of carbon in various waste streams. The production of carbonaceous adsorbents, however, often requires significant post-treatments to enhance both the textural and physico-chemical properties of the adsorbent, as such, the incorporation of surface functionalities is unavoidable and can often lead to significant improvements to the associated CO2 adsorption. This review aims to critically assess the various routes for surface modification of carbonaceous adsorbents and the implications these may have on the incorporation of surface functional groups. Subsequently, the adsorption mechanisms for CO2 on surface-modified porous carbons are discussed in depth with consideration to the influence of the introduced functionalities. The review concludes with a detailed section on current modelling approaches such as the application of artificial intelligence, Monte Carlo, and Density Functional Theory simulations in this realm of research.
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●Review of recent developments in sorption-enhanced steam methane reforming●Technical review of the catalysts and sorbents developed in SE-SMR processes●Technical review of the most recent process ...configuration in SE-SMR processes●Review of application of artificial intelligence techniques in of SE-SMR processes
The European Commission have just stated that hydrogen would play a major role in the economic recovery of post-COVID-19 EU countries. Hydrogen is recognised as one of the key players in a fossil fuel-free world in decades to come. However, commercially practiced pathways to hydrogen production todays, are associated with a considerable amount of carbon emissions. The Paris Climate Change Agreement has set out plans for an international commitment to reduce carbon emissions within the forthcoming decades. A sustainable hydrogen future would only be achievable if hydrogen production is “designed” to capture such emissions. Today, nearly 98% of global hydrogen production relies on the utilisation of fossil fuels. Among these, steam methane reforming (SMR) boasts the biggest share of nearly 50% of the global generation. SMR processes correspond to a significant amount of carbon emissions at various points throughout the process. Despite the dark side of the SMR processes, they are projected to play a major role in hydrogen production by the first half of this century. This that a sustainable, yet clean short/medium-term hydrogen production is only possible by devising a plan to efficiently capture this co-produced carbon as stated in the latest International Energy Agency (IEA) reports. Here, we have carried out an in-depth technical review of the processes employed in sorption-enhanced steam methane reforming (SE-SMR), an emerging technology in low-carbon SMR, for combined carbon capture and hydrogen production. This paper aims to provide an in-depth review on two key challenging elements of SE-SMR i.e. the advancements in catalysts/adsorbents preparation, and current approaches in process synthesis and optimisation including the employment of artificial intelligence in SE-SMR processes. To the best of the authors’ knowledge, there is a clear gap in the literature where the above areas have been scrutinised in a systematic and coherent fashion. The gap is even more pronounced in the application of AI in SE-SMR technologies. As a result, this work aims to fill this gap within the scientific literature.
LINE-1 retrotransposon overexpression is a hallmark of human cancers. We identified a colorectal cancer wherein a fast-growing tumor subclone downregulated LINE-1, prompting us to examine how LINE-1 ...expression affects cell growth. We find that nontransformed cells undergo a TP53-dependent growth arrest and activate interferon signaling in response to LINE-1. TP53 inhibition allows LINE-1
cells to grow, and genome-wide-knockout screens show that these cells require replication-coupled DNA-repair pathways, replication-stress signaling and replication-fork restart factors. Our findings demonstrate that LINE-1 expression creates specific molecular vulnerabilities and reveal a retrotransposition-replication conflict that may be an important determinant of cancer growth.
A microfabricated device has been developed in which electrospray ionization is performed directly from the corner of a rectangular glass microchip. The device allows highly efficient ...electrokinetically driven separations to be coupled directly to a mass spectrometer (MS) without the use of external pressure sources or the insertion of capillary spray tips. An electrokinetic-based hydraulic pump is integrated on the chip that directs eluting materials to the monolithically integrated spray tip. A positively charged surface coating, PolyE-323, is used to prevent surface interactions with peptides and proteins and to reverse the electroosmotic flow in the separation channel. The device has been used to perform microchip CE-MS analysis of peptides and proteins with efficiencies over 200,000 theoretical plates (1,000,000 plates/m). The sensitivity and stability of the microfabricated ESI source were found to be comparable to that of commercial pulled fused-silica capillary nanospray sources.
With Wronskian through the Looking Glass Gorbounov, Vassily; Schechtman, Vadim
Symmetry, integrability and geometry, methods and applications,
01/2021
Journal Article
Recenzirano
Odprti dostop
In the work of Mukhin and Varchenko from 2002 there was introduced a Wronskian map from the variety of full flags in a finite dimensional vector space into a product of projective spaces. We ...establish a precise relationship between this map and the Plücker map. This allows us to recover the result of Varchenko and Wright saying that the polynomials appearing in the image of the Wronsky map are the initial values of the tau-functions for the Kadomtsev-Petviashvili hierarchy.
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