Covalent polymer functionalization of graphene/graphene oxide and its application as anticorrosion materials

Research on grapheme-polymer composites as the promising ion barrier materials to tackle the corrosion issue is rapidly developing and attracts interests from both academia and industry. In this minireview, we highlight the covalent functionalization of graphene and its derivatives such as graphene oxide (GO) with polymer brushes, and their application in anticorrosion within the last 3 years. There are some recent excellent reviews published on single layer graphene and graphene-based polymer composites for anticorrosion. However, the covalent functionalization of graphene and GO with polymer brushes for application in anticorrosion has not been addressed in those reviews. In this review, we describe first the current state of the art of covalent functionalization of graphene/GO with polymer brushes. We then discuss the application of pristine graphene as anticorrosion material and its drawbacks which can be overcome by graphene-based polymer composites. Afterwards, we discuss in detail the recent progress and development of covalent polymer functionalized graphene/GO as anticorrosion coatings, reported within the last 3 years. Finally, as perspective, we will briefly summarize the work on composites of polymers with other two-dimensional (2D) materials as anticorrosion coatings. Herein, hexagonal boron nitride, the most studied 2D materials after graphene, and Ti3C2Tx MXene which is the rising star of 2D transition metal carbide/nitride will be discussed

Does risk aversion affect transmission and generation planning? A Western North America case study

We investigate the effects of risk aversion on optimal transmission and generation expansion planning in a competitive and complete market. To do so, we formulate a stochastic model that minimizes a weighted average of expected transmission and generation costs and their conditional value at risk (CVaR). We show that the solution of this optimization problem is equivalent to the solution of a perfectly competitive risk-averse Stackelberg equilibrium, in which a risk-averse transmission planner maximizes welfare after which risk-averse generators maximize profits. This model is then applied to a 240-bus representation of the Western Electricity Coordinating Council, in which we examine the impact of risk aversion on levels and spatial patterns of generation and transmission investment. Although the impact of risk aversion remains small at an aggregate level, state-level impacts on generation and transmission investment can be significant, which emphasizes the importance of explicit consideration of risk aversion in planning models

Total Endovascular Repair of the Aortic Arch:Initial Experience in the Netherlands

Background. We report procedural and early results in the Netherlands of the Relay Branch device (Terumo Aortic, Sunrise, FL) for total endovascular repair of the aortic arch. Methods. Between 2014 and 2018, all consecutive patients who received the Aortic Relay double-branched stent graft in the Netherlands were included in a multicenter, retrospective registry. Results. The Relay Branch device was used in 11 patients to treat saccular (n = 4), fusiform (n = 5), or false aneurysms (n = 2) in the aortic arch. Patients were deemed unfit or extreme high-risk for open (redo) surgery. The brachiocephalic trunk and left common carotid artery were branched using a retrograde approach in all cases. Additional surgical left subclavian artery revascularization was performed in 8 patients. The main device and the branches were successfully introduced, positioned, and deployed with complete exclusion of the aortic pathology in all patients (100% technical success). There was no retrograde type A dissection or conversion to open surgery. Two procedure-related deaths occurred, both caused by perioperative or postoperative strokes. There were 2 minor strokes with full recovery. One patient recovered from transient paraplegia after spinal fluid drainage. No permanent paraplegia was observed. Follow-up imaging showed persistent adequate exclusion of aortic arch pathology. Mean follow-up was 17 months (range, 3-42 months). Conclusions. Total endovascular aortic arch repair using the Relay Branch device is technically feasible and effective in excluding aortic arch pathology. The observed stroke rate in the initial experience, however, was considerable. Although appealing, this new less-invasive technique should be carefully introduced and its progress thoroughly evaluated. (C) 2020 by The Society of Thoracic Surgeon

Genetic complexity of miscanthus cell wall composition and biomass quality for biofuels

BACKGROUND: Miscanthus sinensis is a high yielding perennial grass species with great potential as a bioenergy feedstock. One of the challenges that currently impedes commercial cellulosic biofuel production is the technical difficulty to efficiently convert lignocellulosic biomass into biofuel. The development of feedstocks with better biomass quality will improve conversion efficiency and the sustainability of the value-chain. Progress in the genetic improvement of biomass quality may be substantially expedited by the development of genetic markers associated to quality traits, which can be used in a marker-assisted selection program. RESULTS: To this end, a mapping population was developed by crossing two parents of contrasting cell wall composition. The performance of 182 F1 offspring individuals along with the parents was evaluated in a field trial with a randomized block design with three replicates. Plants were phenotyped for cell wall composition and conversion efficiency characters in the second and third growth season after establishment. A new SNP-based genetic map for M. sinensis was built using a genotyping-by-sequencing (GBS) approach, which resulted in 464 short-sequence uniparental markers that formed 16 linkage groups in the male map and 17 linkage groups in the female map. A total of 86 QTLs for a variety of biomass quality characteristics were identified, 20 of which were detected in both growth seasons. Twenty QTLs were directly associated to different conversion efficiency characters. Marker sequences were aligned to the sorghum reference genome to facilitate cross-species comparisons. Analyses revealed that for some traits previously identified QTLs in sorghum occurred in homologous regions on the same chromosome. CONCLUSION: In this work we report for the first time the genetic mapping of cell wall composition and bioconversion traits in the bioenergy crop miscanthus. These results are a first step towards the development of marker-assisted selection programs in miscanthus to improve biomass quality and facilitate its use as feedstock for biofuel production

Covalent polymer functionalization of graphene/graphene oxide and its application as anticorrosion materials

Research on grapheme-polymer composites as the promising ion barrier materials to tackle the corrosion issue is rapidly developing and attracts interests from both academia and industry. In this minireview, we highlight the covalent functionalization of graphene and its derivatives such as graphene oxide (GO) with polymer brushes, and their application in anticorrosion within the last 3 years. There are some recent excellent reviews published on single layer graphene and graphene-based polymer composites for anticorrosion. However, the covalent functionalization of graphene and GO with polymer brushes for application in anticorrosion has not been addressed in those reviews. In this review, we describe first the current state of the art of covalent functionalization of graphene/GO with polymer brushes. We then discuss the application of pristine graphene as anticorrosion material and its drawbacks which can be overcome by graphene-based polymer composites. Afterwards, we discuss in detail the recent progress and development of covalent polymer functionalized graphene/GO as anticorrosion coatings, reported within the last 3 years. Finally, as perspective, we will briefly summarize the work on composites of polymers with other two-dimensional (2D) materials as anticorrosion coatings. Herein, hexagonal boron nitride, the most studied 2D materials after graphene, and Ti3C2Tx MXene which is the rising star of 2D transition metal carbide/nitride will be discussed