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The Staged Combustion of Meat-and-Bone Meal:The Characteristics of Conversion Sub-processes and Large-Scale Process Outputs
- Marcin Kantorek
- Krzysztof Jesionek
- Sylwia Polesek-Karczewska
- Paweł Ziółkowski
- Janusz Badur
2021
t Organic waste has been playing an increasingly important role in the energy market as those that may support the economies in pursuing towards decarbonization by increasing the share of renewables in the overall energy balance. In this group of alternative fuels, meat-and-bone meals being a post-production waste of the steadily developing meat industry, constitute a considerable proportion. Though they are rich in minerals, their direct use as natural fertilizer has been restricted to eliminate the spread of potential pathogens. This has focused the worldwide interest on thermal utilization of this type of fuel. Still, there are relatively few units dedicated to deal with large streams of meals. To provide their safe destruction, the conversion process must ensure specific conditions regarding the temperature and residence time. Therefore, most technologies developed to date involve the fluidized bed combustion. By virtue of nature and the variety of physicochemical properties of animal meals, the in-depth analyses of a raw material and its thermal behaviour need to be carried out on the way to develop the efficient and low-emission conversion technology. The concept of the said staged combustion of animal meal has therefore been supported by extensive studies, including the investigation of specific issues related to the process stages, such as drying, devolatilization, gas and char combustion. The developed technology appears to respond to the challenges encountered in the conversion of waste organics, providing the possibility to utilize fuels with a moisture content of up to 90%wt, while keeping the acceptable emission levels (NOx, CO, SO2 and HCl). The 12 MW operating pilot-scale plant tested while supplied with meat-and-bone meal has exhibited high efficiency, 88.4–84.8% depending on a facility load, offering a complete fuel combustion resulting in a flue gas being free from flammable gas compounds, and the ashes with low percentages of combustibles.
The Toolbox of Methods for Multidirectional Characterization of Dietary Nucleic Acids; Verification for Raw and Processed Food Products
- Joanna Cieślewicz
- Zuzanna Koziara
- Wiktoria Ćwiklińska
- Agnieszka Bartoszek-Pączkowska
2021 Pełny tekst Food Analytical Methods
Currently, the nutritional value of food is associated mainly with components such as proteins, carbohydrates, and lipids. However, another important macromolecules present in many foods are dietary nucleic acids (dietNA), i.e., DNA as well as both coding and non-coding RNAs. In the context of food chemistry and nutrition, dietNA are nowadays vastly neglected. In consequence, there are no dedicated methodologies to characterize dietNA. In this study, using raw or processed meat and plant products as model foodstuffs, we developed a toolbox of methods borrowed from other fields (histology, toxicology, molecular biology) that enable the initial characterization of dietNA as a necessary step on the way to systematic evaluation of their nutritional role. The proposed set of methods embraces (i) paraffin embedding of food samples and their staining to visualize the distribution and variety of dietNA in situ; (ii) comet assay to assess integrity of nuclear DNA with possible detection of DNA damage; (iii) dietNA isolation with and without RNAse digestion to determine the content of both DNA and RNA; (iv) electrophoretic separation of isolates to profile dietNA fragments. Such a combined methodological approach revealed clear differences between dietNA derived from raw and processed food products. We believe that the presented set of methods will encourage the broader research on dietNA to understand their role as a nutritionally relevant food component.
The Touristification of Italian Historic City Centres: The Lesson for Central Europe about the Airbnb Eruption
- Łukasz Bugalski
2021
The unparalleled scale of the recent growth in tourism – the rise of the number of temporary visitors – could not have emerged without the impact on other socio‑economic aspects, namely, a change on the part of the destinations. Especially historic city centres are vulnerable to such an impact that could be manifested through diverse transformations of public space usage, housing market economics, availability of services, employment market, cultural heritage management, and everyday life of ordinary residents. Those processes may be indicated as the so‑called “touristification” – the kind of gentrification caused by the uncontrollable growth of the tourism economy. Therefore, together with the latest eruption of the short‑term rental market, identified with the foundation of the peer‑to‑peer Airbnb platform, those processes seem to accelerate and lead to the state of saturation known as “overtourism.” And as such, the ongoing touristification should be positioned in the very centre of urban tourism studies – the intersection of tourism studies and wider understand urban studies – becoming a fundamental issue for the future of the globe.
The unstable thermoelectric effect in non-stoichiometric Cu2Se during the non-equilibrium phase transition
- Bartosz Trawiński
- Marcin Łapiński
- Bogusław Kusz
2021 Pełny tekst JOURNAL OF MATERIALS SCIENCE
The superionic α ↔ β phase transition in Cu1.96Se thermoelectric material is investigated by means of thermal analysis (DSC) and measurements of Seebeck coefficient and electrical conductivity. Results of the DSC measurements with 1–10 K/min heating and cooling rates show that the material is close to the equilibrium phase composition during the transformation. However, the kinetic limitation of the process exists, which is indicated by supercooling. At the beginning of the β → α transition, the most significant kinetic delay was attributed to the nucleation of the α phase. During the phase transformation, the Seebeck coefficient was lower than in a stabilised material (measured with 0.1 K/min heating/cooling rate). During cooling, a decrease from 130 μV/K (in a stabilised measurement) to 7 μV/K (5 K/min cooling rate) was observed. The deviation from the expected values of the Seebeck coefficient was correlated with the difference between the actual and equilibrium phase compositions.
The usage of the openBIM idea in architectural design on the example of Blender and BlenderBIM add-on
- Michał Malewczyk
2021 Pełny tekst Architectus
The aim of the article is the research about the method and advancement of the openBIM idea implementation, clearly defined by the buildingSMART organization. The conducted analysis are limited to the Blender program and the BlenderBIM add-on and has been embedded in the context of the work of an architect and other IT solutions. The article presents four aspects of the openBIM concept implementation. The first approach relates to process of data exchanging between different computer applications using the open IFC standard. Another two focus on the method of creating and coding the three-dimensional geometry itself, through the prism of cooperation between various entities and further editing possibilities. The last aspect deals with the extension of the openBIM concept by combining it with the open-source idea. The author bases his considerations on the existing, analyzed scientific material, as well as on his own experience in the everyday of a designer and a teacher.
The Use of Cluster Analysis to Evaluate the Impact of COVID-19 Pandemic on Daily Water Demand Patterns
- Paulina Dzimińska
- Stanisław Drzewiecki
- Marek Ruman
- Klaudia Kosek
- Karol Mikołajewski
- Paweł Licznar
2021 Pełny tekst Sustainability
Proper determination of unitary water demand and diurnal distribution of water consumption (water consumption histogram) provides the basis for designing, dimensioning, and all analyses of water supply networks. It is important in the case of mathematical modelling of flows in the water supply network, particularly during the determination of nodal water demands in the context of Extended Period Simulation (EPS). Considering the above, the analysis of hourly water consumption in selected apartment buildings was performed to verify the justification of the application of grouping by means of k-means clustering. The article presents a detailed description of the adopted methodology, as well as the obtained results in the form of synthetic distributions of hourly water consumption, and the effect of the COVID-19 pandemic on their change.
The use of thermal imaging camera to estimate velocity profiles based on temperature distribution in a free convection boundary layer
- Michał Ryms
- Krzysztof Tesch
- Witold Lewandowski
2021 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
This work describes an attempt to assess whether the temperature field from a thermal imaging camera can be converted into a velocity field with an accuracy sufficient for qualitative conducting or describing the phenomenon, i.e. when the Navier-Stokes, Fourier-Kirchhoff and continuity equations are mutually coupled. The consequence of this link between temperature fields and velocity is the possibility to formulate the hypothesis that knowledge of the temperature field value is theoretically synonymous with knowledge of the velocity field value. To examine this statement, both experimental and computational research were carried out. The experimental study involved determining the air temperature field by means of a thermal imaging camera in the vicinity of a vertical isothermal plate during free convection heat transfer. The calculation procedure leading from raw data obtained with an IR camera to the velocities has been presented. The calculation results were validated by comparing them with the results of experimental tests carried out under the same conditions. In addition, a comparative analysis using numerical calculations has also been carried out. Satisfactory compliance with current studies has been achieved in both cases.
Theoretical Encapsulation of Fluorouracil (5-FU) Anti-Cancer Chemotherapy Drug into Carbon Nanotubes (CNT) and Boron Nitride Nanotubes (BNNT)
- Maryam Zarghami Dehaghani
- Farrokh Yousefi
- S. Mohammad Sajadi
- Muhammad Tajammal Munir
- Otman Abida
- Sajjad Habibzadeh
- Amin Hamed Mashhadzadeh
- Navid Rabiee
- Ebrahim Mostafavi
- Mohammad Saeb
2021 Pełny tekst MOLECULES
Introduction: Chemotherapy with anti-cancer drugs is considered the most common approach for killing cancer cells in the human body. However, some barriers such as toxicity and side effects would limit its usage. In this regard, nano-based drug delivery systems have emerged as cost-effective and efficient for sustained and targeted drug delivery. Nanotubes such as carbon nanotubes (CNT) and boron nitride nanotubes (BNNT) are promising nanocarriers that provide the cargo with a large inner volume for encapsulation. However, understanding the insertion process of the anti-cancer drugs into the nanotubes and demonstrating drug-nanotube interactions starts with theoretical analysis. Methods: First, interactions parameters of the atoms of 5-FU were quantified from the DREIDING force field. Second, the storage capacity of BNNT (8,8) was simulated to count the number of drugs 5-FU encapsulated inside the cavity of the nanotubes. In terms of the encapsulation process of the one drug 5-FU into nanotubes, it was clarified that the drug 5-FU was more rapidly adsorbed into the cavity of the BNNT compared with the CNT due to the higher van der Waals (vdW) interaction energy between the drug and the BNNT. Results: The obtained values of free energy confirmed that the encapsulation process of the drug inside the CNT and BNNT occurred spontaneously with the free energies of −14 and −25 kcal·mol−1, respectively. Discussion: However, the lower value of the free energy in the system containing the BNNT unraveled more stability of the encapsulated drug inside the cavity of the BNNT comparing the system having CNT. The encapsulation of Fluorouracil (5-FU) anti-cancer chemotherapy drug (commercial name: Adrucil®) into CNT (8,8) and BNNT (8,8) with the length of 20 Å in an aqueous solution was discussed herein applying molecular dynamics (MD) simulation.
Theoretical investigation of the structural insights of the interactions of γ-Fe2O3 nanoparticle with (EMIM TFSI) ionic liquid
- Adam Sieradzan
- Cezary Czaplewski
- Aleksandra Bielicka-Gieldon
- Maciej Bobrowski
- Artur Gieldon
2021 JOURNAL OF MOLECULAR LIQUIDS
One of the possible applications of ionic liquids is to produce electricity from heat. The iron oxide nanoparticle is a potent electrical particle, which is expected to improve the heat’s efficiency to electricity conversion, however, it is prone to aggregation and sedimentation, which hamper its application. One of the methods to enhance the nanoparticle’s solubility and electrical properties is the use of a stabilizing component in the production and application process. In this research, we studied, how the nanoparticle affects the properties of the 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI) ionic liquid. The citric acid was used as a nanoparticle stabilizing agent and led to decrease of the diffusion coefficient of the ionic liquid’s components. Our results indicated, that with the addition of the citric acid, strong solvation sphere around nanoparticle was formed. The presence of nanoparticles significantly reduced the diffusion of ionic liquid components. Finally, the citric acid was found to be the strongest nanoparticle binding component of the studied system, and therefore it was able to stabilize the nanoparticle in solution.
Therapeutic Potential of Multifunctional Derivatives of Cholinesterase Inhibitors
- Maja Przybyłowska
- Krystyna Dzierzbicka
- Szyman Kowalski
- Klaudia Chmielewska
- Iwona Inkielewicz-Stępniak
2021 Pełny tekst Current Neuropharmacology
The aim of this work is review of tacrine analogues from the last three years, which were not included in the latest review work, donepezil and galantamine hybrids from 2015 and rivastigmine derivatives from 2014. In this account we summarize the efforts toward the development and characterization of non-toxic inhibitors of cholinesterases based on mentioned drugs with various interesting additional properties such as antioxidant, decreasing beta-amyloid plaque aggregation, nitric oxide production, pro-inflammatory cytokines release, monoamine oxidase-B activity, cytotoxicity and oxidative stress in vitro and in animal model that classify these hybrids as potential multifunctional therapeutic agents for Alzheimer's disease. Moreover, herein, we have described the cholinergic hypothesis, mechanisms of neurodegeneration and current pharmacotherapy of Alzheimer's disease which is based on the restoration of cholinergic function through blocking enzymes that break down acetylcholine.
Thermal and Hydrodynamic Phenomena in the Stagnation Zone — Impact of the Inlet Turbulence Characteristics on the Numerical Analyses
- Tomasz Kura
- Jan Wajs
- Elzbieta Fornalik-Wajs
- Sasa Kenjeres
- Sebastian Gurgul
2021 Pełny tekst ENERGIES
One of the methods of heat transfer enhancement is utilization of the turbulent impinging jets, which were recently applied, for example, in the heat exchangers. Their positive impact on the heat transfer performance was proven, but many questions related to the origin of this impact are still unanswered. In general, the wall-jet interaction and the near-wall turbulence are supposed to be its main reason, but their accurate numerical analysis is still very challenging. The authors’ aim was to construct the numerical model which can represent the real phenomena with good or very good accuracy. Starting with an analysis of single jet and obtaining the agreement with experimental data, it will be possible to extend the model towards the whole minijets heat exchanger. The OpenFOAM software, Bracknell, UK was used for that purpose, with our own implementation of the ζ-f turbulence model. The most difficult area to model is the stagnation region, where the thermal effects are the most intensive and, at the same time, strongly affected by the conditions in the pipe/nozzle/orifice of various size (conventional, mini, micro), from which the jet is injected. In the following article, summary of authors’ findings, regarding significance of the velocity profile and turbulence intensity at the jet place of discharge are presented. In addition, qualitative analysis of the heat transfer enhancement is included, in relation to the inlet conditions. In the stagnation point, Nusselt number differences reached the 10%, while, in general, its discrepancy in relation to inlet conditions was up to 23%.
Thermal and Mechanical Behavior of Elastomers Incorporated with Thermoregulating Microcapsules
- Janusz Datta
- Patrycja Trzebiatowska,
- Ana M. Borreguero
- Irene Izarra
- Ignacio Garrido
- Angel Serrano
- Juan F. Rodríguez
- Manuel Carmona
2021 Pełny tekst Applied Sciences
Polyurethane (PU) is one of the principal polymers in the global plastic market thanks to its versatility and continuous improvement. In this work, PU elastomeric materials having thermoregulating properties through the incorporation of microcapsules (mSD-(LDPE·EVA-RT27)) from low-density polyethylene and vinyl acetate containing paraffin®RT27 as PCM were produced. Elastomers were synthesized while varying the molar ratio [NCO]/[OH] between 1.05 and 1.1 and the microcapsule (MC) content from 0.0 to 20.0 wt.%. The successful synthesis of the PUs was confirmed by IR analyses. All the synthesized elastomers presented a structure formed by a net of spherical microparticles and with a minimum particle size for those with 10 wt.% MC. The density and tensile strength decreased with the MC content, probably due to worse distribution into the matrix. Elastomer E-1.05 exhibited better structural and stability properties for MC contents up to 15 wt.%, whereas E-1.1, containing 20 wt.% MC, revealed mechanical and thermal synergy effects, demonstrating good structural stability and the largest latent heat. Hence, elastomers having a large latent heat (8.7 J/g) can be produced by using a molar ratio [NCO]/[OH] of 1.1 and containing 20 wt.% mSD-(LDPE·EVA-RT27).
Thermal and technological aspects of double face grinding of C45 carbon steel
- Mariusz Deja
- Linus Lichtschlag
- Eckart Uhlmann
2021 Pełny tekst Journal of Manufacturing Processes
In grinding, the contact zone temperature is a decisive factor influencing the achievable surface quality and the grinding tool wear. In contrast to other grinding processes, only few information regarding double face grinding with planetary kinematics when processing steel is known up to date. Since the successive substitution of in-dustrial double-sided lapping processes by double-sided grinding, it has become necessary to the conducted research in order to provide deeper understanding of the process and factors that influence it. To determine the workpiece temperature during grinding of C45 components, silicon temperature sensors were integrated into the workpiece holders and technological investigations were carried out. The influences and interactions of the mean cutting speed, cooling lubricant flow rate and cutting ability of the grinding wheels on the resulting workpiece temperature were analysed. Subsequently, modelling enabled an empirical estimation of the resulting workpiece temperature for processes in the investigated test area. With regard to the design and optimization of processes for machining plane-parallel workpiece surfaces, this model is a helpful tool for avoiding thermally induced workpiece damage and reduction of tool wear. Furthermore, the method can be used to conduct further ex-aminations on the grinding process and to reduce the amount of cooling lubricant used, to improve life cycle assessment.
Thermal Buckling Analysis of Circular Bilayer Graphene sheets Resting on an Elastic Matrix Based on Nonlocal Continuum Mechanics
- M. Ahmad Pour
- M. E. Golmakani
- Mohammad Malikan
2021 Pełny tekst Journal of Applied and Computational Mechanics
In this article, the thermal buckling behavior of orthotropic circular bilayer graphene sheets embedded in the Winkler–Pasternak elastic medium is scrutinized. Using the nonlocal elasticity theory, the bilayer graphene sheets are modeled as a nonlocal double–layered plate that contains small scale effects and van der Waals (vdW) interaction forces. The vdW interaction forces between the layers are simulated as a set of linear springs using the Lennard–Jones potential model. Using the principle of virtual work, the set of equilibrium equations are obtained based on the first-order shear deformation theory (FSDT) and nonlocal differential constitutive relation of Eringen. Differential quadrature method (DQM) is employed to solve the governing equations for simply-supported and clamped boundary conditions. Finally, the effects of the small scale parameter, vdW forces, aspect ratio, elastic foundation, and boundary conditions are considered in detail.
Thermal utilization of meat-and-bone meal using the rotary kiln pyrolyzer and the fluidized bed boiler – The performance of pilot-scale installation
- Marcin Kantorek
- Krzysztof Jesionek
- Sylwia Polesek-Karczewska
- Paweł Ziółkowski
- Michał Stajnke
- Janusz Badur
2021 Pełny tekst RENEWABLE ENERGY
Thermal utilization of meat-and-bone meal (MBM) is subject to stringent regulations that are meant to provide elimination of any potential pathogens. Incineration as well as other possible routes for thermal conversion of MBM are still at the research state. The universal technology was developed that allows to combust various types of waste organic materials, including animal waste, municipal solid waste and sludge, mixed at any ratio with different types of biomass. It provides the possibility to utilize the wasteand- biomass fuel blends of up to 90%wt of moisture content, while maintaining the allowable pollutant emissions and soil contamination. This regards mainly NOx, SO2, HCl and VOC. Contrary to the typical large scale grate boilers used for waste burning, the developed operating pilot-scale plant with a capacity of 12 MW offers the complete combustion of MBM, resulting in a flue gas which is proved to be free of flammable gaseous components and sooty particles in slag and fly ash. The thermal decomposition and combustion of waste using this technology ensures thermal conversion of chemical energy contained in waste and biomass. The efficiency of the prototype installation varied between 84.8 and 88.4% depending on the facility load.
Thermodynamic Analysis of Negative CO2 Emission Power Plant Using Aspen Plus, Aspen Hysys, and Ebsilon Software
- Paweł Ziółkowski
- Paweł Madejski
- Milad Amiri
- Tomasz Kuś
- Kamil Stasiak
- Navaneethan Subramanian
- Halina Pawlak-kruczek
- Janusz Badur
- Łukasz Niedźwiecki
- Dariusz Mikielewicz
2021 Pełny tekst ENERGIES
Abstract: The article presents results of thermodynamic analysis using a zero-dimensional mathematical models of a negative CO2 emission power plant. The developed cycle of a negative CO2 emission power plant allows the production of electricity using gasified sewage sludge as a main fuel. The negative emission can be achieved by the use this type of fuel which is already a “zeroemissive” energy source. Together with carbon capture installation, there is a possibility to decrease CO2 emission below the “zero” level. Developed models of a novel gas cycle which use selected codes allow the prediction of basic parameters of thermodynamic cycles such as output power, efficiency, combustion composition, exhaust temperature, etc. The paper presents results of thermodynamic analysis of two novel cycles, called PDF0 and PFD1, by using different thermodynamic codes. A comparison of results obtained by three different codes offered the chance to verify results because the experimental data are currently not available. The comparison of predictions between three different software in the literature is something new, according to studies made by authors. For gross efficiency (54.74%, 55.18%, and 52.00%), there is a similar relationship for turbine power output (155.9 kW, 157.19 kW, and 148.16 kW). Additionally, the chemical energy rate of the fuel is taken into account, which ultimately results in higher efficiencies for flue gases with increased steam production. A similar trend is assessed for increased CO2 in the flue gas. The developed precise models are particularly important for a carbon capture and storage (CCS) energy system, where relatively new devices mutually cooperate and their thermodynamic parameters affect those devices. Proposed software employs extended a gas–steam turbine cycle to determine the effect of cycle into environment. First of all, it should be stated that there is a slight influence of the software used on the results obtained, but the basic tendencies are the same, which makes it possible to analyze various types of thermodynamic cycles. Secondly, the possibility of a negative CO2 emission power plant and the positive environmental impact of the proposed solution has been demonstrated, which is also a novelty in the area of thermodynamic cycles
Thermodynamic Studies of Interactions between Sertraline Hydrochloride and Randomly Methylated β-Cyclodextrin Molecules Supported by Circular Dichroism Spectroscopy and Molecular Docking Results
- Sylwia Belica-Pacha
- Mateusz Daśko
- Vyacheslav Buko
- Ilya Zavodnik
- Katarzyna Miłowska
- Maria Bryszewska
2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
The interaction between sertraline hydrochloride (SRT) and randomly methylated β-cyclodextrin (RM β CD) molecules have been investigated at 298.15 K under atmospheric pressure. The method used—Isothermal Titration Calorimetry (ITC) enabled to determine values of the thermodynamic functions like the enthalpy (DH), the entropy (DS) and the Gibbs free energy (DG) of binding for the examined system. Moreover, the stoichiometry coefficient of binding (n) and binding/association constant (K) value have been calculated from the experimental results. The obtained outcome was compared with the data from the literature for other non-ionic βCD derivatives interacting with SRT and the enthalpy-entropy compensation were observed and interpreted. Furthermore, the connection of RM β CD with SRT was characterized by circular dichroism spectroscopy (CD) and complexes of βCD derivatives with SRT were characterized through the computational studies with the use of molecular docking (MD).
THERMOMECHANICAL PERFORMANCE OF FLEXIBLE POLYURETHANE FOAMS AS A FUNCTION OF THE ISOCYANATE INDEX
- Aleksander Hejna
- Paulina Kosmela
- Adam Olszewski
- Łukasz Zedler
- Krzysztof Formela
2021
Polyurethane foams are very versatile materials applied in different branches of industry. Their popularity is attributed, among others, to the flexibility in engineering their mechanical performance by the adjustment of their formulations. One of the most crucial factors is the isocyanate index, determining the ratio between the free hydroxyl and isocyanate groups present in the polyurethane system. By the change of this ratio, the mechanical properties of foams may be adjusted. In the presented paper, we presented the isocyanate index's influence during foams’ preparation on their thermomechanical performance analyzed by the dynamic mechanical analysis.
Thermo-Mechanical Simulation of Underwater Friction Stir Welding of Low Carbon Steel
- Shabbir Memon
- Jacek Tomków
- Hesamoddin Aghajani Derazkola
2021 Pełny tekst Materials
This article investigates the flow of materials and weld formation during underwater friction stir welding (UFSW) of low carbon steel. A thermo-mechanical model is used to understand the relation between frictional heat phenomena during the welding and weld properties. To better understand the effects of the water environment, the simulation and experimental results were compared with the sample prepared by the traditional friction stir welding (FSW) method. Simulation results from surface heat diffusion indicate a smaller preheated area in front of the FSW tool declined the total generated heat in the UFSWed case compared to the FSWed sample. The simulation results revealed that the strain rate of steel in the stir zone (SZ) of the FSWed joint is higher than in the UFSWed case. The microstructure of the welded sample shows that SZ’s microstructure at the UFSWed case is more refined than the FSWed case due to the higher cooling rate of the water environment. Due to obtained results, the maximum temperatures of FSWed and UFSWed cases were 1228 °C and 1008 °C. Meanwhile, the simulation results show 1200 °C and 970 °C for conventional and underwater FSW samples, respectively. The maximum material velocity in SZ predicted 0.40 m/s and 0.32 m/s for FSW and underwater FSWed samples. The better condition in the UFSW case caused the ultimate tensile strength of welded sample to increase ~20% compared to the FSW joint.
Thermo-oxidative exfoliation of carbon black from ground tire rubber as potential reinforcement in green tires
- Adeel Hassan
- Zhen Zhang
- Krzysztof Formela
- Shifeng Wang
2021 COMPOSITES SCIENCE AND TECHNOLOGY
Considering the balance between rapidly growing global tire demand and scarcity of natural resources, recycling and reclaiming techniques of tire rubber have become the state of the art. Herein, we set out to implement a self-designed thermo-oxidative reactor for the exfoliation of carbon black (CB) from ground tire rubber, which is efficiently functioned under a thermo-oxidative reclaiming condition without any additive. The exfoliation of CB from rubber vulcanizate was realized by scission of main chain, and of cross-linked network. The degree of scission was discussed through gel permeation chromatography and using Horikx theory. Sol fraction tremendously increased to 66.0% after thermo-oxidative reclamation at 200 °C for 20 min. Thermo-oxidative scission underwent through the oxidative cleavage of main chain, and of sulfur cross-links, proved by Fourier transform infrared spectroscopy. The ultrafine exfoliation of CB from rubber proved by field emission scanning electron microscopy. The exfoliation was further improved by two roll milling. Exfoliated rubber was incorporated within tire rubber composites as a reinforcing material due to the core-shell structured CB, which was observed with increased effects to the rubber composites. This work presents a potential contribution to the industrial recycling for future applications and to control the pollution of waste tires.