30 research outputs found
Closed-loop and chromium-free leather for the circular economy through refining sustainably available plant food waste
No full textCurrently, 80% (1700 km2) of global leather manufacture is tanned with chromium (III) salts, which are not renewable and problematic to recover at end-of-life (Covington 2007). Commercial vegetable tanning agents are extracted from cultivated stocks, which are insufficient to replace the current consumption of chromium (III) salts. Further expansion of existing plantations is not a sustainable method to generate sufficient tannin extracts to meet current demands. Therefore, alternative bio-based waste sources are required to effectively reuse resources and reduce the need for new fossil-based inputs and reduce the environmental footprint of leather manufacture. Literature supports the presence of tannins in coffee waste. Low et al (2015) and Bhoite et al (2013) confirm the presence of both condensed and hydrolysable tannins with C13 NMR and MS data. This observation can be extended to many waste streams in the food and beverage sector. Underpinning tanning application has been demonstrated through trials by Baskar at ICLT, which shows the extracted coffee waste replaces conventional veg tannins which includes both tanning and retanning stages. Typical concentrations of tannins required to fully tan are more than 30% of the hide weight, therefore, the use of waste sources has the potential to replace a significant quantity of leather processing chemicals. Currently at TRL 3, the project aim is to develop a scalable leather manufacturing process with tannins extracted from food and beverage wastes thus replacing Cr and plantation crop tanning agents
Closed-loop and chromium-free leather for the circular economy through refining sustainably available plant food waste
No full textCurrently, 80% (1700 km2) of global leather manufacture is tanned with chromium (III) salts, which are not renewable and problematic to recover at end-of-life (Covington 2007). Commercial vegetable tanning agents are extracted from cultivated stocks, which are insufficient to replace the current consumption of chromium (III) salts. Further expansionof existing plantations is not a sustainable method to generate sufficient tannin extracts to meet current demands. Therefore, alternative bio-based waste sources are required to effectively reuse resources and reduce the need for new fossil-based inputs and reduce the environmental footprint of leather manufacture. Literature supports the presence of tannins in coffee waste. Low et al (2015) and Bhoite et al (2013) confirm the presence of both condensed and hydrolysable tannins with C13 NMR and MS data. This observation can be extended to many waste streams in the food and beverage sector. Underpinning tanning application has been demonstrated through trials by Baskar at ICLT, which shows the extracted coffee waste replaces conventional veg tannins which includes both tanning and retanning stages. Typical concentrations of tannins required to fully tan are more than 30% of the hide weight, therefore, the use of waste sources has the potential to replace a significant quantity of leather processing chemicals. Currently at TRL 3, the project aim is to develop a scalable leather manufacturing process with tannins extracted from food and beverage wastes thus replacing Cr and plantation crop tanning agents
Development of Porous Free Combustion Chamber Prototype Cylinder Head Casting in Sand Casting
No full textImplementing the design for disassembly (DfD) principle in the public procurement process of buildings in the Netherlands: Conceptualization of the implementation of the DfD principle in the public procurement process to achieve circular ambitions
No full textThe building industry is stained as unsustainable due to the linear economy model of “take, make and dispose”. There is a need to switch to Circular Economy (CE). One of the ways in which the public clients can stimulate this transition is by implementing the Design for Disassembly (DfD) principle in the public procurement process. However, this stimulation is underexploited, and public clients seem to lack in having an effective system for implementation. Therefore, the objective of this research was to conceptualize a system for the implementation of the DfD principle in the public procurement process to achieve circular ambitions. A mixed research approach was adopted where first a literature study was conducted on the general procurement process of buildings and the aspects of DfD to conceptualize the DfD based procurement process. Following this, two case studies were conducted to understand how public clients have implemented DfD in the public procurement process of known circular buildings. Based on the results of the case study, the conceptualization of the DfD based procurement process was refined. The main findings from refined conceptualization are: firstly, the client needs to hire a design team specialized in DfD. This design team needs to formulate an ambition primarily for flexibility in design and beyond that for future reuse. Secondly, for the tendering phase, the client needs to set eligibility requirements for the selection of the design team asking for training and experience. They also need to set requirements for the inclusion of deconstruction professionals in the consortium. Finally, the client needs to award the contract based on the design principles of DfD. The client needs to assess the offers for these design principles using BIM-based tools. Also, for the assessment of the cost of the offers, the client needs to use life cycle costs. In conclusion, the implementation of DfD does not lead to a fundamental change in how the procurement process is conducted. Only in certain phases, the activities need to be conducted in line with DfD.Civil Engineering | Construction Management and Engineerin
Investigating the Chemical Nature of Cathode Coatings under Electrochemical Cycling
No full textThe advancements in the field of e-mobility today far outpace all prior projections, and the rate of progress is quick. Due to their high power density and energy density, Lithium-Ion Batteries (LIBs) have grown to be an increasingly appealing alternative for use in electric vehicles. However, over extended use, these batteries frequently experience problems with capacity loss. Additionally, the battery’s current collectors are challenging to scrape off from the cathode, which results in erroneous measurement results under spectroscopic observation. Furthermore, current collectors have a propensity to corrode with repeated use, which reduces the battery’s power output.In this study, the cathodes are manufactured without a current collector, i.e. a Free-Standing (FS) cathode, to prevent the issues brought on by the current collector. To assess how well these cathodes function in comparison to cathodes with an aluminium current collector, they are cycled both for long term and at different charging rates. In this investigation, the cathode materials examined include NMC 532, NMC 811, and LCO. The cycling behaviour of the FS cathodes was found to be quite comparable to that of the cathodes on current collectors. Using Electrochemical Impedance Spectroscopy (EIS), X-Ray Diffraction (XRD), and X-Ray Photon Spectroscopy (XPS), their cycling behaviour was further assessed in order to ascertain the chemical changes that occurred while cycling. The findings showed that an unstable cathode-electrolyte interface layer caused the cathodes to develop cracks on their surface during long-term cycling. Consequently, the electrolyte started to decompose, depositing impurities on the cathode surfaces. This behaviour produced a high impedance and prevented charge transfer over the cathode surface, leading to quick capacity fading and a subpar electrochemical performance.To address the issue of capacity loss, the cathodes under investigation are coated with Al2O3 using Atomic Layer Deposition (ALD). Investigation of these cathodes after cycling revealed that the electrolyte decomposition had been greatly decreased, resulting in a virtually impurity-free surface. Additionally, it was discovered that the thicker the ALD coated layer is, the lower its cycle performance is likely to be, due to the increased charge transfer resistance caused by the thick layer. As a result, it is suggested to keep the coating as thin as possible to gain superior performances. The chemical differences between the coated and uncoated cathodes in this work were examined through EIS, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDS), XRD, XPS and Nuclear Magnetic Resonance Spectroscopy (NMR). In order to examine the chemistry of the coating layer more effectively, it is recommended to carry out NMR measurements at high magnetic fields. Overall, this thesis effectively illustrated the benefits of coating the cathodes with Al2O3. Additionally, it offered a fascinating route for FS electrode-specific research.Electrical Engineering | Sustainable Energy Technolog
The density, dynamic viscosity and kinematic viscosity of protic and aprotic polar solvent (pure and mixed) systems: An experimental and theoretical insight of thermophysical properties
No full textWe report herein the thermophysical properties of pure protic and aprotic polar solvents (water, dimethyl sulfoxide and N,N-dimethyl formamide) and their mixed (binary and ternary) systems. The experimental density (ρ) and viscosity (η) were determined for these systems by varying temperature range from 293.15 K to 343.15 K. The excess properties (viz., excess molar volumes (VE), excess thermal expansion coefficient (αE), viscosity deviation (Δη) and excess Gibb's free energy (ΔGE) for viscous flow) were computed for mixed systems from experimental values. The excess properties of the mixed systems show clearly a non-ideal behaviour. Especially, a mixture of water with aprotic polar component show better thermophysical properties than pure systems. The pure (DMF) system shows increasing dynamic viscosity values at higher temperature region. Both the binary as well as ternary mixed systems show maximum activation energy (Ea) in the presence of water depicts their thermal stability of the mixed systems. The thermal expansion coefficient (α) also revealed increase in the thermal behaviour for the protic-aprotic systems. In addition to that, thermodynamic parameters are also evaluated for better understanding of thermal stability
The density, dynamic viscosity and kinematic viscosity of protic polar solvents (pure and mixed systems) studies: A theoretical insight of thermophysical properties
No full textThe density, dynamic viscosity and kinematic viscosity of protic polar solvents (pure and mixed systems) studies: A theoretical insight of thermophysical properties
No full textThe densities (ρ) and viscosities (η) have been studied for pure and mixed systems of protic polar solvents water, methanol, ethanol and propan-1-ol for entire composition range at temperature from 293 K to 343 K in 5 K intervals at atmospheric pressure. With increase in temperature the density values as well as the dynamic viscosity values were decrease. The obtained values are used to calculate the excess properties such as excess molar free volume (VE), thermal expansion coefficient (α), excess thermal expansion coefficient (αE), viscosity deviation (Δη) and excess Gibb's free energy (ΔG⁎E) for the activation of viscous flow for mixed systems. The calculated excess properties of binary mixtures were correlated with Redlich-Kister type polynomial equation by least square regression method and fitting parameters were found for all binary systems. The temperature dependence of viscosities for mixed systems has been explained using Arrhenius type equation of Newtonian classic solvents and Eyring transition state equation. The thermodynamic parameters were also evaluated for mixed systems which show the thermal stability of system
Use of Online Platforms for Research Visibility amongst Academic Librarians in Maharashtra
No full textThe purpose of the present research work is to look into how academic library professionals in Maharashtra use online platforms to make their research more visible. The study used an online surveying technique through questionnaire and the data was gathered from seventy-one academic librarians within Maharashtra. The results show that the majority of college librarians have an academic network profile. According to most academic librarians, author profiles on various online platforms have several benefits, including drawing more attention to the author and their work, increasing the number of people who read their papers, expanding the audience for their articles, and even attracting funding for future research
Surfactant assisted surface morphology and thermal properties of polythiophene composites
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