Graphene synthesis: Rate and Mechanistic Investigation of Eu(OTf)2-Mediated R...Tufan Ghosh
We describe a fast, efficient, and mild approach to prepare chemically reduced graphene oxide (rGO) at room temperature using divalent europium triflate {Eu(OTf)2}. The characterization of solution-processable reduced graphene oxide has been carried out by various spectroscopic (FT-IR, UV–visible absorption, and Raman), microscopic (TEM and AFM), and powder X-ray diffraction (XRD) techniques. Kinetic study indicates that the bimolecular rate constants for the reduction of graphene oxide are 13.7 ± 0.7 and 5.3 ± 0.1 M–1 s–1 in tetrahydrofuran (THF)–water and acetonitrile (ACN)–water mixtures, respectively. The reduction rate constants are two orders of magnitude higher compared to the values obtained in the case of commonly used reducing agents such as the hydrazine derivative, sodium borohydride, and a glucose–ammonia mixture. The present work introduces a feasible reduction process for preparing reduced graphene oxide at ambient conditions, which is important for bulk production of GO. More importantly, the study explores the possibilities of utilizing the unique chemistry of divalent lanthanide complexes for chemical modifications of graphene oxide.
White light emission from graphene quantum dotsTufan Ghosh
We report herein the synthesis and characterization of unmodified graphene oxide quantum dots (GOQDs) with white-light-emitting properties, upon photoexcitation at 340 nm. The Commission International de l’Éclairage (CIE) 1931 chromaticity coordinates for GOQDs (x = 0.29, y = 0.34) suggest that highly pure white-light emission was achieved. A detailed mechanistic study was carried out utilizing UV–visible absorption, steady-state and time-resolved fluorescence spectroscopy, and dynamic light scattering (DLS) techniques to understand the origin of the white-light emission. The results taken together suggest that GOQDs could self-assemble in solution and thus transform the luminescence behavior. Furthermore, the results indicate that the pH of the medium also plays a crucial role in assisting the aggregation to generate the white-light emission. The concentration-dependent DLS measurements support a cooperative mechanism for the aggregation kinetics in the system. More importantly, the study suggests that white-light emission can be generated from unmodified graphene oxide quantum dots by tuning their nanoscopic aggregation properties.
Volkswagen Presentation to EPA on Diesel Engine Future (2006)Juan Barnett
12th Diesel Engine-Efficiency and Emissions Research (DEER) Conference August 20-24, 2006, Detroit, Michigan
"LNT or Urea SCR Technology: Which is the right technology for TIER 2 BIN 5 passenger vehicles?"
Graphene synthesis: Rate and Mechanistic Investigation of Eu(OTf)2-Mediated R...Tufan Ghosh
We describe a fast, efficient, and mild approach to prepare chemically reduced graphene oxide (rGO) at room temperature using divalent europium triflate {Eu(OTf)2}. The characterization of solution-processable reduced graphene oxide has been carried out by various spectroscopic (FT-IR, UV–visible absorption, and Raman), microscopic (TEM and AFM), and powder X-ray diffraction (XRD) techniques. Kinetic study indicates that the bimolecular rate constants for the reduction of graphene oxide are 13.7 ± 0.7 and 5.3 ± 0.1 M–1 s–1 in tetrahydrofuran (THF)–water and acetonitrile (ACN)–water mixtures, respectively. The reduction rate constants are two orders of magnitude higher compared to the values obtained in the case of commonly used reducing agents such as the hydrazine derivative, sodium borohydride, and a glucose–ammonia mixture. The present work introduces a feasible reduction process for preparing reduced graphene oxide at ambient conditions, which is important for bulk production of GO. More importantly, the study explores the possibilities of utilizing the unique chemistry of divalent lanthanide complexes for chemical modifications of graphene oxide.
White light emission from graphene quantum dotsTufan Ghosh
We report herein the synthesis and characterization of unmodified graphene oxide quantum dots (GOQDs) with white-light-emitting properties, upon photoexcitation at 340 nm. The Commission International de l’Éclairage (CIE) 1931 chromaticity coordinates for GOQDs (x = 0.29, y = 0.34) suggest that highly pure white-light emission was achieved. A detailed mechanistic study was carried out utilizing UV–visible absorption, steady-state and time-resolved fluorescence spectroscopy, and dynamic light scattering (DLS) techniques to understand the origin of the white-light emission. The results taken together suggest that GOQDs could self-assemble in solution and thus transform the luminescence behavior. Furthermore, the results indicate that the pH of the medium also plays a crucial role in assisting the aggregation to generate the white-light emission. The concentration-dependent DLS measurements support a cooperative mechanism for the aggregation kinetics in the system. More importantly, the study suggests that white-light emission can be generated from unmodified graphene oxide quantum dots by tuning their nanoscopic aggregation properties.
Volkswagen Presentation to EPA on Diesel Engine Future (2006)Juan Barnett
12th Diesel Engine-Efficiency and Emissions Research (DEER) Conference August 20-24, 2006, Detroit, Michigan
"LNT or Urea SCR Technology: Which is the right technology for TIER 2 BIN 5 passenger vehicles?"
Presentation given by Paul Fennell of Imperial College London on "The Integration of Power Generation, Cement Manufacture, Biomass Utilisation and Calcium Looping." at the Alternative CCS Pathways Workshop, Oxford Martin School, 27 June 2014
Presentation given by Richard T. J. Porter from ETII, University of Leeds, on "CO2QUEST Typical Impurities in Captured CO2 Streams" at the EC FP7 Projects: Leading the way in CCS implementation event, London, 14-15 April 2014
Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment St...Michael Hewitt, GISP
Jon Smoyer P.G., PA Department of Environmental Protection (DEP), “Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment Strategy”
Hydrogen Peroxide has been used to oxidize and remove ferrous iron from mine drainage for decades. It is a relatively inexpensive and effective oxidant that can be used to achieve rapid ferrous iron oxidation in many active and semi-passive mine drainage treatment systems. This presentation outlines the physical properties, concentrations, and available delivery options for hydrogen peroxide.
Evaluation of CO2 Storage Capacity and EOR in the Bakken Shale Oil ReservoirsHamid Lashgari
This paper presents a new perspective in modeling and analyzing efficiency of CO2 and miscible gas injection for potential enhanced oil recovery (EOR) and CO2 storage in shale oil plays. Our major focuses are conceptual and fundamental understanding of the dominant trapping and oil recovery mechanisms behind miscible gas injection. The efficiency of the CO2 Huff-n-Puff process in shale oil production has been widely investigated in recent years because of the ultra-low permeability (1 to 100 µD) of shale oil reservoirs and poor geological connectivity between hydraulic fractured wells. Here we used hydrocarbon fluid properties of a Middle Bakken tight oil reservoir, and considered a wide range of permeability (from 1 to 100µD) and isotherm adsorption properties for CO2 and CH4. A large scale numerical model was set up to simulate and capture the important mechanisms behind various miscible gas injection scenarios.
Simulation results reveal that CO2 adsorption and CH4 desorption along with molecular diffusion of hydrocarbon components are crucial in the presence of organic matter content and pores, however, recycle enriched gas injection demonstrated a high oil recovery compared to miscible CO2 injection. Although CO2 adsorption is large in organic rich shale oil based on literature measurements, CO2 efficiency in enhancing oil recovery is not as much as recycle enriched gas with ethane (C2). However, CO2 trapping may be substantial due to adsorption (5.0% to 10%) and other conventional trapping mechanisms, and the amount of CO2 trapped could be a significant fraction of the total injected amount (25% to 50% considering other trapping mechanisms such as CO¬2 dissolution, residual, and free gas). Simulation results strongly support that CO2 molecular diffusion can assist in the deep penetration of CO2 to touch larger surface area of matrix to become adsorbed, as well as dissolved in other coexisting phases and residual trapping.
Presentation given by Paul Fennell of Imperial College London on "The Integration of Power Generation, Cement Manufacture, Biomass Utilisation and Calcium Looping." at the Alternative CCS Pathways Workshop, Oxford Martin School, 27 June 2014
Presentation given by Richard T. J. Porter from ETII, University of Leeds, on "CO2QUEST Typical Impurities in Captured CO2 Streams" at the EC FP7 Projects: Leading the way in CCS implementation event, London, 14-15 April 2014
Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment St...Michael Hewitt, GISP
Jon Smoyer P.G., PA Department of Environmental Protection (DEP), “Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment Strategy”
Hydrogen Peroxide has been used to oxidize and remove ferrous iron from mine drainage for decades. It is a relatively inexpensive and effective oxidant that can be used to achieve rapid ferrous iron oxidation in many active and semi-passive mine drainage treatment systems. This presentation outlines the physical properties, concentrations, and available delivery options for hydrogen peroxide.
Evaluation of CO2 Storage Capacity and EOR in the Bakken Shale Oil ReservoirsHamid Lashgari
This paper presents a new perspective in modeling and analyzing efficiency of CO2 and miscible gas injection for potential enhanced oil recovery (EOR) and CO2 storage in shale oil plays. Our major focuses are conceptual and fundamental understanding of the dominant trapping and oil recovery mechanisms behind miscible gas injection. The efficiency of the CO2 Huff-n-Puff process in shale oil production has been widely investigated in recent years because of the ultra-low permeability (1 to 100 µD) of shale oil reservoirs and poor geological connectivity between hydraulic fractured wells. Here we used hydrocarbon fluid properties of a Middle Bakken tight oil reservoir, and considered a wide range of permeability (from 1 to 100µD) and isotherm adsorption properties for CO2 and CH4. A large scale numerical model was set up to simulate and capture the important mechanisms behind various miscible gas injection scenarios.
Simulation results reveal that CO2 adsorption and CH4 desorption along with molecular diffusion of hydrocarbon components are crucial in the presence of organic matter content and pores, however, recycle enriched gas injection demonstrated a high oil recovery compared to miscible CO2 injection. Although CO2 adsorption is large in organic rich shale oil based on literature measurements, CO2 efficiency in enhancing oil recovery is not as much as recycle enriched gas with ethane (C2). However, CO2 trapping may be substantial due to adsorption (5.0% to 10%) and other conventional trapping mechanisms, and the amount of CO2 trapped could be a significant fraction of the total injected amount (25% to 50% considering other trapping mechanisms such as CO¬2 dissolution, residual, and free gas). Simulation results strongly support that CO2 molecular diffusion can assist in the deep penetration of CO2 to touch larger surface area of matrix to become adsorbed, as well as dissolved in other coexisting phases and residual trapping.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
3. • Prereading / Discussion material
• Data Analysis
• Preparing / Organising meetings for discussion
Project Outline
3
4. Sinter
• Agglomerate
• Ferrous Material
• Coke breeze
• Fluxes
Reducibility
• The extent of which oxygen is removed from the iron oxides in the
burden.
Reduction-disintegration
• Haematite → Magnetite
• Weakened structure
4
Definitions
5. ISO 4695
Reducibility 5
• Heated at 950oC
• Reducing gas: 40% CO (4.5 L/m), 60% N2 (10.5L/m)
• Reducibility Index, RI = 33.9 / (t60 – t30)
• t60 – time taken to achieve 60% reduction, t30 – time taken to achieve 30% reduction
• Aim: ~1
6. HOSIM
Reducibility 6
• Programmable temperature function up to 900oC
• Gas composition adjusted throughout, made up of CO, CO2, H2 and N2
• Reducibility = Time taken to achieve pre-determined end-point
• HOSIM value / Reduction disintegration = Percentage of fines under 3.15 mm
• HOSIM value aim: 24%
13. • M. Geerdes, H. Toxopeus and C. Vliet, Modern blast furnace
ironmaking, IOS Press, Amsterdam, 2009.
• U. Yadav, B. Pandey, B. Das and D. Jena, Ironmaking & Steelmaking,
2002, 29, 91-95.
• F. Shen, X. Jiang, G. Wu, G. Wei, X. Li and Y. Shen, ISIJ International,
2006, 46, 65-69.
• T. Umadevi, K. Nelson, P. Mahapatra, M. Prabhu and M.
Ranjan, Ironmaking & Steelmaking, 2009, 36, 515-520.
• T. Umadevi, P. Karthik, P. Mahapatra, M. Prabhu and M.
Ranjan, Ironmaking & Steelmaking, 2012, 39, 180-189.
References
13
Editor's Notes
For the past six months I have been working with the ironworks technical team on several different projects, with a main focus in discussions about sinter reducibility testing. At present, sinter reducibility here is tested using the ISO 4695 procedure, which is a standard method used at many different sinter plants. However, there is also another method of testing, known as the HOSIM test that was developed my Ijmuiden in the Netherlands who we have previously sent samples to for testing, but this ceased a few years ago and was replaced by a predicted HOSIM value which is generated by a modelled formula.
During this presentation I will talk about what it was I was tasked to do, some background on the tests and reducibility, analysis, outcomes, difficulties I came across and future steps I believe would be beneficial.
