25 research outputs found
Understanding Governance and Regulation of CO2 Storage in Europe
Climate change, continued economic development, and energy security have become increasingly pressing issues over the past two decades or so. One potential solution to this interrelated problem is the idea to capture the carbon dioxide (CO2) from large stationary emission sources, such as power plants, and permanently store it deep underground. In this way CO2 emissions can be prevented from reaching the atmosphere, whilst allowing for a continued use of fossil fuels, until other alternatives (i.e. wind, solar, biomass) are developed on a wider scale. This process is also referred to as carbon capture and storage (CCS). The literature review in this thesis identifies the need to present a more in-depth picture of the entire process of governance of CO2 storage.
The aim of this research is therefore to examine the extent to which the current legal and regulatory frameworks are able to mediate between managing the environmental risks of CO2 storage and the development/deployment of CCS in Europe. The analysis is underlined by the governance network theory (GNT), borrowing also elements from the theory of bounded rationality. Along with an extensive doctrinal legal scholarship, data analysis is also supported by 15 in-depth interviews with key CCS stakeholders in Europe.
The results show that there is a wide consensus that the current legal and regulatory frameworks are robust enough, albeit the existence of uncertainty in regards to a number of legal provisions. There is also wide agreement between stakeholders in regards to the ability of operators to manage the environmental risks of CO2 storage.
The discussion of these results show the applicability of the GNT as a framework for studying the management of environmental risks of CO2 storage, and the development and deployment of CCS technology in conjunction. Implications drawn from these findings also show that the management of environmental risks of CO2 storage and the future of CCS technology depends heavily on the effective relationship between the government agencies (i.e. competent authority) and project developers. Furthermore, good communication and engagement with other stakeholders, in particular the general public, will also be significant in the future development/deployment of CCS projects in Europe. When these relationships are good, this research argues that efficiency gains of governance are realised
Acorn: Developing full-chain industrial carbon capture and storage in a resource- and infrastructure-rich hydrocarbon province
Research to date has identified cost and lack of support from stakeholders as two key barriers to the development of a carbon dioxide capture and storage (CCS) industry that is capable of effectively mitigating climate change. This paper responds to these challenges through systematic evaluation of the research and development process for the Acorn CCS project, a project designed to develop a scalable, full-chain CCS project on the north-east coast of the UK. Through assessment of Acorn's publicly-available outputs, we identify strategies which may help to enhance the viability of early-stage CCS projects. Initial capital costs can be minimised by infrastructure re-use, particularly pipelines, and by re-use of data describing the subsurface acquired during oil and gas exploration activity. Also, development of the project in separate stages of activity (e.g. different phases of infrastructure re-use and investment into new infrastructure) enables cost reduction for future build-out phases. Additionally, engagement of regional-level policy makers may help to build stakeholder support by situating CCS within regional decarbonisation narratives. We argue that these insights may be translated to general objectives for any CCS project sharing similar characteristics such as legacy infrastructure, industrial clusters and an involved stakeholder-base that is engaged with the fossil fuel industry
Dexamethasone-Loaded Bioactive Coatings on Medical Grade Stainless Steel Promote Osteointegration
In this study, a multilayer bioactive coating based on carboxymethyl cellulose (CMC) and dexamethasone (DEX) was prepared on medical-grade stainless steel (AISI 316LVM). Its aim was the controlled drug delivery of the incorporated anti‑inflammatory drug, which at the same time promotes osteogenic differentiation of mesenchymal stem cells. Due to DEX’s limited solubility in physiological fluids, which limits the loading capacity of coatings, it was further combined with β-cyclodextrin to increase its concentration in the bioactive coating. Controlled release of DEX from the multilayer coating was achieved in four steps: a “burst”, i.e., very fast, release step (in an immersion interval of 0–10 min), a fast release step (10–30 min), a slow-release step (60–360 min), and a plateau step (360–4320 min), following a zero-order release or Higuchi model release mechanism. Successful layer-by-layer coating formation was confirmed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). It was shown that the application of the coating significantly increases the hydrophilic character of AISI 316LVM, and also significantly increases the surface roughness, which is known to promote cell growth. In addition, electrochemical measurements demonstrated that the coating application does not increase the susceptibility of medical-grade stainless steel to corrosion. In vitro cell testing using all cell types with which such coatings come into contact in the body (osteoblasts, chondrocytes, and mesenchymal stem cells (MSCs)) showed very good biocompatibility towards all of the mentioned cells. It further confirmed that the coatings promoted MSCs osteogenic differentiation, which is the desired mode of action for orthopedic implants
Microvascular Tissue Engineering—A Review
Tissue engineering and regenerative medicine have come a long way in recent decades, but the lack of functioning vasculature is still a major obstacle preventing the development of thicker, physiologically relevant tissue constructs. A large part of this obstacle lies in the development of the vessels on a microscale—the microvasculature—that are crucial for oxygen and nutrient delivery. In this review, we present the state of the art in the field of microvascular tissue engineering and demonstrate the challenges for future research in various sections of the field. Finally, we illustrate the potential strategies for addressing some of those challenges
Algorithmic linearization improves Syringe-based extrusion in elastic systems using Hydrogel-based materials
Accuracy and precision are essential in extrusion-based material handling such as three-dimensional (3D) bioprinting. However, the elasticity of components, backlash, variability of nozzle and cartridge shapes, etc. can lead to unpredictable printing results, which is further complicated by the wide range of rheologically diverse materials and complex sample designs. To address this issue, we present an algorithmic approach to compensate for the discrepancies between piston motion and material extrusion in syringe-based extrusion systems. This approach relies on cyclical, iterative optimization through rapid piston movements, which are adjusted based on extrusion analysis. In this work we establish a general theoretical framework for extrusion and link the rheological properties of prepared hydrogels with shear rates in a typical bioprinting process. The determined properties are compared with the success of the developed algorithm to modify machine instructions for precise material deposition of short, interrupted lines, as well as multi-layered scaffold structures. Overall, our approach provides a means of improving the accuracy and precision of complex extrusion-based bioprinting systems, without prior knowledge of set-up or material properties, making it highly versatile and suitable for a wide range of applications, particularly when the combined set-up and material properties are too complex for solely predictive approaches
Development of a novel NiCu nanoparticle-loaded polysaccharide-based hydrogel for 3D printing of customizable dressings with promising cytotoxicity against melanoma cells
Hybrid 3D Printing of Advanced Hydrogel-Based Wound Dressings with Tailorable Properties
Despite the extensive utilization of polysaccharide hydrogels in regenerative medicine, current fabrication methods fail to produce mechanically stable scaffolds using only hydrogels. The recently developed hybrid extrusion-based bioprinting process promises to resolve these current issues by facilitating the simultaneous printing of stiff thermoplastic polymers and softer hydrogels at different temperatures. Using layer-by-layer deposition, mechanically advantageous scaffolds can be produced by integrating the softer hydrogel matrix into a stiffer synthetic framework. This work demonstrates the fabrication of hybrid hydrogel-thermoplastic polymer scaffolds with tunable structural and chemical properties for applications in tissue engineering and regenerative medicine. Through an alternating deposition of polycaprolactone and alginate/carboxymethylcellulose gel strands, scaffolds with the desired architecture (e.g., filament thickness, pore size, macro-/microporosity), and rheological characteristics (e.g., swelling capacity, degradation rate, and wettability) were prepared. The hybrid fabrication approach allows the fine-tuning of wettability (approx. 50–75°), swelling (approx. 0–20× increased mass), degradability (approx. 2–30+ days), and mechanical strength (approx. 0.2–11 MPa) in the range between pure hydrogels and pure thermoplastic polymers, while providing a gradient of surface properties and good biocompatibility. The controlled degradability and permeability of the hydrogel component may also enable controlled drug delivery. Our work shows that the novel hybrid hydrogel-thermoplastic scaffolds with adjustable characteristics have immense potential for tissue engineering and can serve as templates for developing novel wound dressings
CX43 Expression in Colonic Adenomas and Surrounding Mucosa Is a Marker of Malignant Potential
Colorectal cancer is a major public health problem. The adenoma-carcinoma sequence offers potential for screening and surveillance. We tested the clinical behavior and diagnostic utility of connexin 43 (CX43) in connection with pathohistological risk. Immunohistochemical expression of CX43 in colonic adenomas and surrounding mucosa from 87 patients was determined. CX43 expression was higher in mucosa surrounding adenomas with high-grade dysplasia (p=0.047), larger adenomas (p=0.015) and villous adenomas (p=0.02). No difference of CX43 expression in adenomas according to grade of dysplasia was found (p=0.87). CX43 expression in adenomas was dependent on the patient's hemoglobin level (p=0.002), family history of colorectal cancer (p=0.009) and statin therapy (p=0.049). CX43 expression in mucosa surrounding adenoma could be an additional factor indicative of malignant potential. CX43 expression in colonic adenoma seems to be closely related to family history of colorectal cancer, statin therapy and hemoglobin level