| 1. |
- Tatipala, Sravan, et al.
(författare)
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A hybrid data- and model-based approach to process monitoring and control in sheet metal forming
- 2020
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- The ability to predict and control the outcome of the sheet metal forming process demands holistic knowledge of the product/process parameter influences and their contribution in shaping the output product quality. Recent improvements in the ability to harvest in-line production data and the increased capability to understand complex process behaviour through computer simulations open up the possibility for new approaches to monitor and control production process performance and output product quality. This research presents an overview of the common process monitoring and control approaches while highlighting their limitations in handling the dynamics of the sheet metal forming process. The current paper envisions the need for a collaborative monitoring and control system for enhancing production process performance. Such a system must incorporate comprehensive knowledge regarding process behaviour and parameter influences in addition to the current-system-state derived using in-line production data to function effectively. Accordingly, a framework for monitoring and control within automotive sheet metal forming is proposed. The framework addresses the current limitations through the use of real-time production data and reduced process models. Lastly, the significance of the presented framework in transitioning to the digital manufacturing paradigm is reflected upon.
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| 2. |
- Acharya, Sarthak, et al.
(författare)
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Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:9
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Tidskriftsartikel (refereegranskat)abstract
- Advancements in production techniques in PCB manufacturing industries are still required as compared to silicon-ICs fabrications. One of the concerned areas in PCBs fabrication is the use of conventional methodologies for metallization. Most of the manufacturers are still using the traditional Copper (Cu) laminates on the base substrate and patterning the structures using lithography processes. As a result, significant amounts of metallic parts are etched away during any mass production process, causing unnecessary disposables leading to pollution. In this work, a new approach for Cu metallization is demonstrated with considerable step-reducing pattern-transfer mechanism. In the fabrication steps, a seed layer of covalent bonded metallization (CBM) chemistry on top of a dielectric epoxy resin is polymerized using actinic radiation intensity of a 375 nm UV laser source. The proposed method is capable of patterning any desirable geometries using the above-mentioned surface modification followed by metallization. To metallize the patterns, a proprietary electroless bath has been used. The metallic layer grows only on the selective polymer-activated locations and thus is called selective metallization. The highlight of this production technique is its occurrence at a low temperature (20–45 °C). In this paper, FR-4 as a base substrate and polyurethane (PU) as epoxy resin were used to achieve various geometries, useful in electronics packaging. In addition, analysis of the process parameters and some challenges witnessed during the process development are also outlined. As a use case, a planar inductor is fabricated to demonstrate the application of the proposed technique.
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| 3. |
- Ahmad, Shabir, et al.
(författare)
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A Distributed Approach towards Improved Dissemination Protocol for Smooth Handover in MediaSense IoT Platform
- 2018
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- Recently, the Internet has been utilized by many applications to convey time-sensitive messages. The persistently expanding Internet coverage and its easy accessibility have offered to ascend to a problem which was once regarded as not essential to contemplate. Nowadays, the Internet has been utilized by many applications to convey time-sensitive messages. Wireless access points have widely been used but these access points have limitations regarding area coverage. So for covering a wider space, various access points need to be introduced. Therefore, when the user moves to some other place, the devices expected to switch between access points. Packet loss amid the handovers is a trivial issue. MediaSense is an Internet of Things distributed architecture enabling the development of the IoT application faster. It deals with this trivial handover issue by utilizing a protocol called Distributed Context eXchange Protocol. However, this protocol is centralized in nature and also suffers in a scenario when both sender and receiver address change simultaneously. This paper presents a mechanism to deal with this scenario and presents a distributed solution to deal with this issue within the MediaSense platform. The proposed protocol improves dissemination using retransmission mechanism to diminish packet loss. The proposed protocol has been delineated with a proof of concept chat application and the outcomes have indicated a significant improvement in terms of packet loss.
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| 4. |
- Anukam, Anthony, et al.
(författare)
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A Review of the Chemistry of Anaerobic Digestion : Methods of Accelerating and Optimizing Process Efficiency
- 2019
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Ingår i: Processes. - Basel : MDPI. - 2227-9717. ; 7:8, s. 1-19
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Forskningsöversikt (refereegranskat)abstract
- The anaerobic digestion technology has been in existence for centuries and its underlying theory established for decades. It is considered a useful technology for the generation of renewable energy, and provides means to alleviate problems associated with low access to energy. However, a great deal of current research is targeted towards the optimization of this technology under diverse digestion process conditions. This review presents an in-depth analysis of the chemistry of anaerobic digestion and discusses how process chemistry can be used to optimize system performance through identification of methods that can accelerate syntrophic interactions of different microorganisms for improved methanogenic reactions. Recent advances in addition to old research are discussed in order to offer a general but comprehensive synopsis of accumulated knowledge in the theory of anaerobic digestion, as well as an overview of previous research and future directions and opportunities of the AD technology. Achieving a sustainable energy system requires comprehensive reforms in not just economic, social and policy aspects, but also in all technical aspects, which represents one of the most crucial future investments for anaerobic digestion systems.
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| 5. |
- Arrhenius, Karine, et al.
(författare)
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Detection of contaminants in hydrogen fuel for fuel cell electrical vehicles with sensors—available technology, testing protocols and implementation challenges
- 2022
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Europe’s low-carbon energy policy favors a greater use of fuel cells and technologies based on hydrogen used as a fuel. Hydrogen delivered at the hydrogen refueling station must be compliant with requirements stated in different standards. Currently, the quality control process is performed by offline analysis of the hydrogen fuel. It is, however, beneficial to continuously monitor at least some of the contaminants onsite using chemical sensors. For hydrogen quality control with regard to contaminants, high sensitivity, integration parameters, and low cost are the most important requirements. In this study, we have reviewed the existing sensor technologies to detect contaminants in hydrogen, then discussed the implementation of sensors at a hydrogen refueling stations, described the state-of-art in protocols to perform assessment of these sensor technologies, and, finally, identified the gaps and needs in these areas. It was clear that sensors are not yet commercially available for all gaseous contaminants mentioned in ISO14687:2019. The development of standardized testing protocols is required to go hand in hand with the development of chemical sensors for this application following a similar approach to the one undertaken for air sensors. © 2021 by the authors.
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| 6. |
- Bastin, G., et al.
(författare)
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Metabolic flux analysis of VERO cells under various culture conditions
- 2021
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:12
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Tidskriftsartikel (refereegranskat)abstract
- Although the culture of VERO cells in bioreactors is an important industrial bioprocess for the production of viruses and vaccines, surprisingly few reports on the analysis of the flux distribution in the cell metabolism have been published. In this study, an attempt is made to fill this gap by providing an analysis of relatively simple metabolic networks, which are constructed to describe the cell behavior in different culture conditions, e.g., the exponential growth phase (availability of glucose and glutamine), cell growth without glutamine, and cell growth without glucose and glutamine. The metabolic networks are kept as simple as possible in order to avoid underdeterminacy linked to the lack of extracellular measurements, and a unique flux distribution is computed in each case based on a mild assumption that the macromolecular composition of the cell is known. The result of this computation provides some insight into the metabolic changes triggered by the culture conditions, which could support the design of feedback control strategies in fed batch or perfusion bioreactors where the lactate concentration is measured online and regulated by controlling the delivery rates of glucose and, possibly, of some essential amino acids.
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| 7. |
- Bhattacharyya, Shubhankar, et al.
(författare)
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Melt Stable Functionalized Organosolv and Kraft Lignin Thermoplastic
- 2020
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- A shift towards an economically viable biomass biorefinery concept requires the use of all biomass fractions (cellulose, hemicellulose, and lignin) for the production of high added-value products. As lignin is often underutilized, the establishment of lignin valorization routes is highly important. In-house produced organosolv as well as commercial Kraft lignin were used in this study. The aim of the current work was to make a comparative study of thermoplastic biomaterials from two different types of lignins. Native lignins were alkylate with two different alkyl iodides to produce ether-functionalized lignins. Successful etherification was verified by FT-IR spectroscopy, changes in the molecular weight of lignin, as well as 13C and 1H Nuclear Magnetic Resonance (NMR). The thermal stability of etherified lignin samples was considerably improved with the T2% of organosolv to increase from 143 °C to up to 213 °C and of Kraft lignin from 133 °C to up to 168 °C, and glass transition temperature was observed. The present study shows that etherification of both organosolv and Kraft lignin with alkyl halides can produce lignin thermoplastic biomaterials with low glass transition temperature. The length of the alkyl chain affects thermal stability as well as other thermal properties.
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| 8. |
- Carlsson, Leo S., et al.
(författare)
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Modeling the Effect of Scrap on the Electrical Energy Consumption of an Electric Arc Furnace
- 2020
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- The melting time of scrap is a factor that affects the Electrical Energy (EE) consumption of the Electric Arc Furnace (EAF) process. The EE consumption itself stands for most of the total energy consumption during the process. Three distinct representations of scrap, based partly on the apparent density and shape of scrap, were created to investigate the effect of scrap on the accuracy of a statistical model predicting the EE consumption of an EAF. Shapley Additive Explanations (SHAP) was used as a tool to investigate the effects by each scrap category on each prediction of a selected model. The scrap representation based on the shape of scrap consistently resulted in the best performing models while all models using any of the scrap representations performed better than the ones without any scrap representation. These results were consistent for all four distinct and separately used cleaning strategies on the data set governing the models. In addition, some of the main scrap categories contributed to the model prediction of EE in accordance with the expectations and experience of the plant engineers. The results provide significant evidence that a well-chosen scrap categorization is important to improve a statistical model predicting the EE and that experience on the specific EAF under study is essential to evaluate the practical usefulness of the model.
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| 9. |
- Darwish, Esraa, 1986, et al.
(författare)
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Effect of mn and cu substitution on the srfeo 3 perovskite for potential thermochemical energy storage applications
- 2021
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:10
-
Tidskriftsartikel (refereegranskat)abstract
- Perovskites are well-known oxides for thermochemical energy storage applications (TCES) since they show a great potential for spontaneous O2 release due to their non-stoichiometry. Transition-metal-based perovskites are particularly promising candidates for TCES owing to their different oxidation states. It is important to test the thermal behavior of the perovskites for TCES applications; however, the amount of sample that can be used in thermal analyses is limited. The use of redox cycles in fluidized bed tests can offer a more realistic approach, since a larger amount of sample can be used to test the cyclic behavior of the perovskites. In this study, the oxygen release/consumption behavior of Mn-or Cu-substituted SrFeO3 (SrFe0.5M0.5O3; M: Mn or Cu) under redox cycling was investigated via thermal analysis and fluidized bed tests. The reaction enthalpies of the perovskites were also calculated via differential scanning calorimetry (DSC). Cu substitution in SrFeO3 increased the performance significantly for both cyclic stability and oxygen release/uptake capacity. Mn substitution also increased the cyclic stability; however, the presence of Mn as a substitute for Fe did not improve the oxygen release/uptake performance of the perovskite.
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| 10. |
- Dawod, Ahmed, et al.
(författare)
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UPLC-QToF Nanospray MS and NMR Analysis of Ficus sycomorus Stem Bark and Its Effects on Rabbit
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, a phytochemical of Ficus sycomorus (Moraceae family) was screened, and the effect of this extract on rabbit performance indices, immunity, and carcass quality measures was determined. Ficus sycomorus samples were collected, air-dried, and extracted with 70% methanol to prepare a solution of 100 mg/mL concentration. The extract was subjected to high-resolution mass spectrometric measurements via ultra-high performance liquid chromatography-quadrupole time-of-flight-nanospray mass spectrometry (UPLC-QToF-MS) and 1H NMR analysis. Forty-eight male rabbits, one-month-old, belonging to the Blanc de Bouscat and New Zealand White breeds were selected and distributed equally in a 2 x 3 factorial trial. The rabbits within each breed received F. sycomorus extract at the dose of 0, 100, and 200 mg/kg for 60 days. Blood samples were collected and serum obtained for the detection of liver enzymes, serum lipids, and proteins. The results of UPLC-QToF-MS and molecular networking analysis revealed the presence of procyanidin B2, procyanidin A1, genistein, eriodyctiol, catechin, luteolin, biochanin A, and chlorogenic acid that might exhibit various pharmaceutical activities. However, the F. sycomorus extract reduced rabbit performance indices and carcass quality measures. In addition, this extract significantly depressed the low-density lipoprotein and triglycerides, which may indicate the antidyslipidemia effect of this extract on rabbits.
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| 11. |
- Encalada-Dávila, Ángel, et al.
(författare)
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Transport parameter correlations for digitally created PEFC gas diffusion layers by using openPNM
- 2021
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:7
-
Tidskriftsartikel (refereegranskat)abstract
- A polymer electrolyte fuel cell (PEFC) is an electrochemical device that converts chemical energy into electrical energy and heat. The energy conversion is simple; however, the multiphysics phenomena involved in the energy conversion process must be analyzed in detail. The gas diffusion layer (GDL) provides a diffusion media for reactant gases and gives mechanical support to the fuel cell. It is a complex medium whose properties impact the fuel cell’s efficiency. Therefore, an in-depth analysis is required to improve its mechanical and physical properties. In the current study, several transport phenomena through three-dimensional digitally created GDLs have been analyzed. Once the porous microstructure is generated and the transport phenomena are mimicked, transport parameters related to the fluid flow and mass diffusion are computed. The GDLs are approximated to the carbon paper represented as a grouped package of carbon fibers. Several correlations, based on the fiber diameter, to predict their transport properties are proposed. The digitally created GDLs and the transport phenomena have been modeled using the open-source library named Open Pore Network Modeling (OpenPNM). The proposed correlations show a good fit with the obtained data with an R-square of approximately 0.98.
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| 12. |
- Farooq, Muhammad, et al.
(författare)
-
Thermodynamic Performance Analysis of Hydrofluoroolefins (HFO) Refrigerants in Commercial Air-Conditioning Systems for Sustainable Environment
- 2020
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:2
-
Tidskriftsartikel (refereegranskat)abstract
- Global warming is one of most severe environmental concerns that our planet is facing today. One of its causes is the previous generation of refrigerants that, upon release, remain in the atmosphere for longer periods and contribute towards global warming. This issue could potentially be solved by replacing the previous generation's high global warming potential (GWP) refrigerants with environmentally friendly refrigerants. This scenario requires an analysis of new refrigerants for a comparison of the thermodynamic properties of the previously used refrigerants. In the present research, a numerical study was conducted to analyze the thermodynamic performance of specifically low GWP hydrofluoroolefens (HFO) refrigerants for an actual vapor compression refrigeration cycle (VCRC) with a constant degree of 3 K superheat. The output parameters included the refrigeration effect, compressor work input, the coefficient of performance (COP), and the volumetric refrigeration capacity (VRC), all of which were calculated by varying the condenser pressure from 6 to 12 bars and vapor pressure from 0.7 to 1.9 bars. Results showed that R1234ze(Z) clearly possessed the desired thermodynamic performance. The drop in refrigeration effect for R1234ze(Z) was merely 14.6% less than that of R134a at a 12 bar condenser pressure; this was minimum drop among candidate refrigerants. The drop in the COP was the minimum for R1234ze(Z)-5.1% less than that of R134a at a 9 bar condenser pressure and 4.7% less than that of R134a at a 1.9 bar evaporator pressure, whereas the COP values of the other refrigerants dropped more drastically at higher condenser pressures. R1234ze(Z) possessed favorable thermodynamic characteristics, with a GWP of 7, and it can serve as an alternative refrigerant for refrigeration systems for a sustainable environment.
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| 13. |
- Frodeson, Stefan, Universitetsadjunkt, 1968-, et al.
(författare)
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The Potential for a Pellet Plant to Become a Biorefinery
- 2019
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Ingår i: Processes. - Basel : MDPI. - 2227-9717. ; 7:4, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- The use of bioenergy has increased globally in recent years, as has the utilization of biomaterials for various new product solutions through various biorefinery concepts. In this study, we introduce the concept of using a mechanical dewatering press in combination with thermal drying in a pellet plant. The purpose of the study is to increase the understanding of the effects a mechanical dewatering press has in a pellet production chain and investigate whether a pellet plant could thus become a biorefinery. The evaluations in this study are based on industrial data and initial tests at the university. The results show that the concept of using the mechanical dewatering press together with a packed moving bed dryer reduces energy use by 50%, compared to using only a packed moving bed dryer. The press water could be used as a raw material for biogas, bioplastics, and biohydrogen. Hence, this study points out the possibilities of a pellet plant increasing the efficiency of the drying step, while moving towards becoming a biorefinery.
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| 14. |
- Gerlach, Inga, et al.
(författare)
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Conceptual Design of an Operator Training Simulator for a Bio-Ethanol Plant
- 2015
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Ingår i: Processes. - : MPDI Open Access Publishing. - 2227-9717. ; 3:3, s. 664-683
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Tidskriftsartikel (refereegranskat)abstract
- Conceptual design methodology for the configuration and procedural training with an operating training simulator (OTS) in a large-scale plant for commercial bio-ethanol production is described. The aim of the study is to show how the methodology provides a powerful way for finding the best configuration and training structure of the OTS before constructing and implementing the software of the OTS. The OTS principle, i.e., to use a computer-based virtual representation of the real process plant intended for efficient training of process operators, has long since been applied in aviation and process industries for more efficient and flawless operations. By using the conceptual design methodology (sometimes referred to as bio-mechatronics) a variety of OTS configurations with this capacity was generated. The systematic approach of for targeting the users’ (i.e., the plant management and process operators) needs resulted in better understanding and efficiency in training of hands-on skills in operating the plant. The training included general standard operating procedures for running the plant under normal operation conditions with different starch materials, handling of typical frequent disturbances as well as acting in situations not described in the standard operation procedures and applying trouble-shooting
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| 15. |
- Gerlach, Inga, et al.
(författare)
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Operator Training Simulator for an Industrial Bioethanol Plant
- 2016
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 4:4
-
Tidskriftsartikel (refereegranskat)abstract
- Operator training simulators (OTS) are software tools for training process operators in large-scale industrial applications. Here, we describe the development, implementation and training of an OTS for a large-scale industrial plant for bioethanol production. The design of the OTS is based on conceptual analysis (previously reported by us in this journal) of various configuration alternatives and training procedures at the plant. In this article, we report on how the conceptual design is used in simulation models and graphical user interfaces and how the design is applied for training of operators in the real plant environment. The results imply that OTS would be time-and cost-efficient tools for application in the biotechnological industry.
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| 16. |
- Gevari, Moein Talebian, et al.
(författare)
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Influence of Fluid Properties on Intensity of Hydrodynamic Cavitation and Deactivation of Salmonella typhimurium
- 2020
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:3
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, three microfluidic devices with different geometries are fabricated on silicon and are bonded to glass to withstand high-pressure fluid flows in order to observe bacteria deactivation effects of micro cavitating flows. The general geometry of the devices was a micro orifice with macroscopic wall roughness elements. The width of the microchannel and geometry of the roughness elements were varied in the devices. First, the thermophysical property effect (with deionized water and phosphate-buffered saline (PBS)) on flow behavior was revealed. The results showed a better performance of the device in terms of cavitation generation and intensity with PBS due to its higher density, higher saturation vapor pressure, and lower surface tension in comparison with water. Moreover, the second and third microfluidic devices were tested with water and Salmonella typhimurium bacteria suspension in PBS. Accordingly, the presence of the bacteria intensified cavitating flows. As a result, both devices performed better in terms of the intensity of cavitating flow with the presence of bacteria. Finally, the deactivation performance was assessed. A decrease in the bacteria colonies on the agar plate was detected upon the tenth cycle of cavitating flows, while a complete deactivation was achieved after the fifteenth cycle. Thus, the proposed devices can be considered as reliable hydrodynamic cavitation reactors for "water treatment on chip" applications.
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| 17. |
- Giorcelli, Mauro, et al.
(författare)
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A Review of Bio-Oil Production through Microwave-Assisted Pyrolysis
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:3
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Forskningsöversikt (refereegranskat)abstract
- The issue of sustainability is a growing concern and has led to many environmentally friendly chemical productions through a great intensification of the use of biomass conversion processes. Thermal conversion of biomass is one of the most attractive tools currently used, and pyrolytic treatments represent the most flexible approach to biomass conversion. In this scenario, microwave-assisted pyrolysis could be a solid choice for the production of multi-chemical mixtures known as bio-oils. Bio-oils could represent a promising new source of high-value species ranging from bioactive chemicals to green solvents. In this review, we have summarized the most recent developments regarding bio-oil production through microwave-induced pyrolytic degradation of biomasses.
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| 18. |
- Gros, Sébastien, 1977
(författare)
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An analysis of the Directional-Modifier Adaptation algorithm based on Optimal Experimental Design
- 2017
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Ingår i: Processes. - : MDPI AG. - 2227-9717.
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Tidskriftsartikel (refereegranskat)abstract
- The modifier approach has been extensively explored and offers a theoretically-sound and practically-useful method to deploy real-time optimization. The recent directional-modifier adaptation algorithm offers a heuristic to tackle the modifier approach. The directional-modifier adaptation algorithm, supported by strong theoretical properties and the ease of deployment in practice, proposes a meaningful compromise between process optimality and quickly improving the quality of the estimation of the gradient of the process cost function. This paper proposes a novel view of the directional-modifier adaptation algorithm, as an approximation of the optimal trade-off between the underlying experimental design problem and the process optimization problem. It moreover suggests a minor modification in the tuning of the algorithm, so as to make it a more genuine approximation
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| 19. |
- Hamedi, Naser, et al.
(författare)
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Simulation of Flexible Fibre Particle Interaction with a Single Cylinder
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the flow of a fibre suspension in a channel containing a cylinder was numerically studied for a very low Reynolds number. Further, the model was validated against previous studies by observing the flexible fibres in the shear flow. The model was employed to simulate the rigid, semi-flexible, and fully flexible fibre particle in the flow past a single cylinder. Two different fibre lengths with various flexibilities were applied in the simulations, while the initial orientation angle to the flow direction was changed between 45° ≤ θ ≤ 75°. It was shown that the influence of the fibre orientation was more significant for the larger orientation angle. The results highlighted the influence of several factors affecting the fibre particle in the flow past the cylinder.
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| 20. |
- Holmqvist, Anders, et al.
(författare)
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Methods and Tools for Robust Optimal Control of Batch Chromatographic Separation Processes
- 2015
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 3:3, s. 568-606
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Tidskriftsartikel (refereegranskat)abstract
- This contribution concerns the development of generic methods and tools for robust optimal control of high-pressure liquid chromatographic separation processes. The proposed methodology exploits a deterministic robust formulation, that employs a linearization of the uncertainty set, based on Lyapunov differential equations to generate optimal elution trajectories in the presence of uncertainty. Computational tractability is obtained by casting the robust counterpart problem in the framework of bilevel optimal control where the upper level concerns forward simulation of the Lyapunov differential equation, and the nominal open-loop optimal control problem augmented with the robustified target component purity inequality constraint margin is considered in the lower level. The lower-level open-loop optimal control problem, constrained by spatially discretized partial differential equations, is transcribed into a finite dimensional nonlinear program using direct collocation, which is then solved by a primal-dual interior point method. The advantages of the robustification strategy are highlighted through the solution of a challenging ternary complex mixture separation problem for a hydrophobic interaction chromatography system. The study shows that penalizing the changes in the zero-order hold control gives optimal solutions with low sensitivity to uncertainty. A key result is that the robustified general elution trajectories outperformed the conventional linear trajectories both in terms of recovery yield and robustness.
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| 21. |
- Hossain, Md Shakhawath, et al.
(författare)
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Explicit-pH Coarse-Grained Molecular Dynamics Simulations Enable Insights into Restructuring of Intestinal Colloidal Aggregates with Permeation Enhancers
- 2022
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 10:1, s. 29-
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Tidskriftsartikel (refereegranskat)abstract
- Permeation enhancers (PEs) can increase the bioavailability of drugs. The mechanisms of action of these PEs are complex, but, typically, when used for oral administration, they can transiently induce the alteration of trans- and paracellular pathways, including increased solubilization and membrane fluidity, or the opening of the tight junctions. To elucidate these mechanistic details, it is important to understand the aggregation behavior of not only the PEs themselves but also other molecules already present in the intestine. Aggregation processes depend critically on, among other factors, the charge state of ionizable chemical groups, which is affected by the pH of the system. In this study, we used explicit-pH coarse-grained molecular dynamics simulations to investigate the aggregation behavior and pH dependence of two commonly used PEs—caprate and SNAC—together with other components of fasted- and fed-state simulated intestinal fluids. We also present and validate a coarse-grained molecular topology for the bile salt taurocholate suitable for the Martini3 force-field. Our results indicate an increase in the number of free molecules as a function of the system pH and for each combination of FaSSIF/FeSSIF and PEs. In addition, there are differences between caprate and SNAC, which are rationalized based on their different molecular structures and critical micelle concentrations.
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| 22. |
- Hussain, Abrar, et al.
(författare)
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Carotenoid Extraction from Locally and Organically Produced Cereals Using Saponification Method
- 2021
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Carotenoids are important phytochemicals contributing nutritional health benefits in the human diet, with a significant contribution from cereals as one of the major food component around the world. Different methods have been described and adopted for the extraction and isolation of carotenoid compounds. Saponification can be seen as an option for carotenoid extraction from cereals as it converts retinol esters to retinol and removes other abundant compounds such as triglycerides. Extraction of carotenoids content of locally adapted and organic cereals have been limitedly investigated and was, therefore, evaluated in the present study, with a specific aim to understand genotypic and local cultivation effects and interactions. Therefore, 17 diverse cereal genotypes of local origin were grown organically in four localities and evaluated for carotenoid content and composition by HPLC. The results showed a large variation in content and composition of carotenoids in locally adapted and organically grown cereal genotypes, with lutein as the dominating type in wheat and rye, while zeaxanthin was the dominating type in barley. High-level genotypes showed values (9.9 mg/kg of total carotenoids) similar to the highest values previously reported in specific types of wheat. The barley genotypes showed relatively high stability in carotenoids content within and between cultivation locations, while large interactions were found with the cultivation location for the rest of the genotypes, indicating their local adaptation. The local adaptation of the cereal genotypes evaluated contributes large opportunities for local production of high value, highly nutritious food products, while the direct value of these genotypes for conventional plant breeding for varieties performing similar over broad environmental ranges, are more limited.
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| 23. |
- Håkansson, Andreas
(författare)
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Rotor-stator mixers : From batch to continuous mode of operation-A review
- 2018
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 6:4
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Forskningsöversikt (refereegranskat)abstract
- Although continuous production processes are often desired, many processing industries still work in batch mode due to technical limitations. Transitioning to continuous production requires an in-depth understanding of how each unit operation is affected by the shift. This contribution reviews the scientific understanding of similarities and differences between emulsification in turbulent rotor-stator mixers (also known as high-speed mixers) operated in batch and continuous mode. Rotor-stator mixers are found in many chemical processing industries, and are considered the standard tool for mixing and emulsification of high viscosity products. Since the same rotor-stator heads are often used in both modes of operation, it is sometimes assumed that transitioning from batch to continuous rotor-stator mixers is straight-forward. However, this is not always the case, as has been shown in comparative experimental studies. This review summarizes and critically compares the current understanding of differences between these two operating modes, focusing on shaft power draw, pumping power, efficiency in producing a narrow region of high intensity turbulence, and implications for product quality differences when transitioning from batch to continuous rotor-stator mixers.
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| 24. |
- Håkansson, Andreas
(författare)
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The Role of Stochastic Time-Variations in Turbulent Stresses When Predicting Drop Breakup—A Review of Modelling Approaches
- 2021
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:11
-
Forskningsöversikt (refereegranskat)abstract
- Many industrially relevant emulsification devices are of the high-energy type, where drop deformation and subsequent breakup, take place due to intense turbulent fluid–drop interactions. This includes high-pressure homogenizers as well as rotor-stator mixers (also known as high-shear mixers) of various designs. The stress acting on a drop in a turbulent flow field varies over time, occasionally reaching values far exceeding its time-averaged value, but only during limited stretches of time, after which it decreases down to low values again. This it is one factor separating turbulent from laminar emulsification. This contribution reviews attempts to take this intermittently time-varying stress into account in models predicting the characteristic drop diameter resulting from emulsification experiments, focusing on industrially applicable emulsification devices. Two main frameworks are discussed: the Kolmogorov–Hinze framework and the oscillatory resonance framework. Modelling suggestions are critically discussed and compared, with the intention to answer how critical it is to correctly capture this time-varying stress in emulsification modelling. The review is concluded by a list of suggestions for future investigations.
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| 25. |
- Håkansson, Andreas
(författare)
-
Towards a standard method for estimating fragmentation rates in emulsification experiments
- 2021
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:12
-
Tidskriftsartikel (refereegranskat)abstract
- The fragmentation rate function connects the fundamental drop breakup process with the resulting drop size distribution and is central to understanding or modeling emulsification processes. There is a large interest in being able to reliably measure it from an emulsification experiment, both for generating data for validating theoretical fragmentation rate function suggestions and as a tool for studying emulsification processes. Consequently, several methods have been suggested for measuring fragmentation rates based on emulsion experiments. Typically, each study suggests a new method that is rarely used again. The lack of an agreement on a standard method has become a substantial challenge. This contribution critically and systematically analyses four influential suggestions of how to measure fragmentation rate in terms of validity, reliability, and sensitivity to method assumptions. The back-calculation method is identified as the most promising—high reliability and low sensitivity to assumption—whereas performing a non-linear regression on a parameterized model (as commonly suggested) is unsuitable due to its high sensitivity. The simplistic zero-order method is identified as an interesting supplemental tool that could be used for qualitative comparisons but not for quantification.
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| 26. |
- Högosta, Johanna, et al.
(författare)
-
Sensitivity Analysis of the Climate Effect of Using Pyrochar Biofuel for Heat and Electricity Generation
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:10, s. 1-17
-
Tidskriftsartikel (refereegranskat)abstract
- This study aims to quantify the climate change impact of pyrochar production from pulp and paper mill sludge and the subsequent utilisation in combined heat and power (CHP) plants for co-generation of heat and electricity using the environmental life cycle assessment (E-LCA) method. In the Pyrochar Scenario, in which the sludge is pyrolyzed into pyrochar, the authors have assumed that pyrochar would replace coal. In the Reference Scenario, sludge is incinerated with a subsequent low rate of energy recovery. A comprehensive sensitivity analysis was performed to determine the conditions in which the sludge pyrochar would offer the greatest climate-effect benefits. The parameters selected for the said analysis are the form of pyrochar (pellet or powder), fuels replaced by it in the CHP plant (solid waste and peat vis-à-vis coal), and the utilisation of the pyrochar fuel in another European country (Germany and Spain vis-à-vis Sweden). The results of this E-LCA clearly show that using pyrochar as a biofuel in CHP plants delivered a considerable reduction in greenhouse gas (GHG) emissions (−1.87 tonne CO2-eq per 2.8 tonne dry sludge). Contribution analysis reveals that the process accounting for the biggest share of the reduction is the pyrochar combustion (a negative contribution of 76%), which results in a displacement of coal-based fuels. The authors conclude that the utilisation of pyrochar in firing units would provide the highest reduction in GHG emissions, while recommending a comprehensive economic analysis in addition to climate effect assessment, before making a decision regarding the introduction of sludge pyrochar to the energy sector.
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| 27. |
- Ilanidis, Dimitrios, et al.
(författare)
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Factors affecting detoxification of softwood enzymatic hydrolysates using sodium dithionite
- 2021
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:5
-
Tidskriftsartikel (refereegranskat)abstract
- Conditioning of lignocellulosic hydrolysates with sulfur oxyanions, such as dithionite, is one of the most potent methods to improve the fermentability by counteracting effects of inhibitory by-products generated during hydrothermal pretreatment under acidic conditions. The effects of pH, treatment temperature, and dithionite dosage were explored in experiments with softwood hydrolysates, sodium dithionite, and Saccharomyces cerevisiae yeast. Treatments with dithionite at pH 5.5 or 8.5 gave similar results with regard to ethanol productivity and yield on initial glucose, and both were always at least ~20% higher than for treatment at pH 2.5. Experiments in the dithionite concentration range 5.0–12.5 mM and the temperature range 23–110◦ C indicated that treatment at around 75◦ C and using intermediate dithionite dosage was the best option (p ≤ 0.05). The investigation indicates that selection of the optimal temperature and dithionite dosage offers great benefits for the efficient fermentation of hydrolysates from lignin-rich biomass, such as softwood residues. © 2021 by the authors.
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| 28. |
- Jafari, Mohammad, et al.
(författare)
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Effects of Conventional Flotation Frothers on the Population of Mesophilic Microorganisms in Different Cultures
- 2019
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 7:10
-
Tidskriftsartikel (refereegranskat)abstract
- Bioleaching is an environment-friendly and low-investment process for the extraction of metals from flotation concentrate. Surfactants such as collectors and frothers are widely used in the flotation process. These chemical reagents may have inhibitory effects on the activity of microorganisms through a bioleaching process; however, there is no report indicating influences of reagents on the activity of microorganisms in the mixed culture which is mostly used in the industry. In this investigation, influences of typical flotation frothers (methyl isobutyl carbinol and pine oil) in different concentrations (0.01, 0.10, and 1.00 g/L) were examined on activates of bacteria in the mesophilic mixed culture (Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Acidithiobacillus thiooxidans). For comparison purposes, experiments were repeated by pure cultures of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans in the same conditions. Results indicated that increasing the dosage of frothers has a negative correlation with bacteria activities while the mixed culture showed a lower sensitivity to the toxicity of these frothers in comparison with examined pure cultures. Outcomes showed the toxicity of Pine oil is lower than methyl isobutyl carbinol (MIBC). These results can be used for designing flotation separation procedures and to produce cleaner products for bio extraction of metals.
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| 29. |
- Jamil, Asif, et al.
(författare)
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Polyetherimide-Montmorillonite Nano-Hybrid Composite Membranes : CO2 Permeance Study via Theoretical Models
- 2020
-
Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- The incorporation of aminolauric acid modified montmorillonite (f-MMT) in polyetherimide (PEI) has been implemented to develop hollow fibre nano-hybrid composite membranes (NHCMs) with improved gas separation characteristics. The aforementioned characteristics are caused by enhanced f-MMT spatial dispersion and interfacial interactions with PEI matrix. In this study, existing gas permeation models such as, Nielsen, Cussler, Yang-Cussler, Lape-Cussler and Bharadwaj were adopted to estimate the dispersion state of f-MMT and to predict the CO2 permeance in developed NHCMs. It was found out that the average aspect ratio estimated was 53, with 3 numbers of stacks per unit tactoid, which showed that the intercalation f-MMT morphology is the dominating dispersion state of filler in PEI matrix. Moreover, it was observed that Bharadwaj model showed the least average absolute relative error (%AARE) values till 3 wt. % f-MMT loading in the range of +/- 10 for a pressure range of 2 to 10 bar. Hence, Bharadwaj was the best fit model for the experimental data compared to other models, as it considers the platelets orientation.
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| 30. |
- Johansson, Mathias, et al.
(författare)
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Faba Bean Fractions for 3D Printing of Protein-, Starch- and Fibre-Rich Foods
- 2022
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Food 3D printing allows for the production of personalised foods in terms of shape and nutrition. In this study, we examined whether protein-, starch- and fibre-rich fractions extracted from faba beans can be combined to produce fibre- and protein-rich printable food inks for extrusion-based 3D printing. Small amplitude oscillatory shear measurements were used to characterise the inks while compression tests and scanning electron microscopy were used to characterise the freeze-dried samples. We found that rheological parameters such as storage modulus, loss tangent and yield stress were related to ink printability and shape stability. Investigations on the effect of ink composition, infill pattern (honeycomb/grid) and direction of compression on textural and microstructural properties of freeze-dried 3D-printed objects revealed no clear effect of infill pattern, but a strong effect of direction of compression. Microstructure heterogeneity seemed to be correlated with the textural properties of the printed objects.
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| 31. |
- Ladd, Brian, et al.
(författare)
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Proof-of-Concept of Continuous Transfection for Adeno-Associated Virus Production in Microcarrier-Based Culture
- 2022
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 10:3
-
Tidskriftsartikel (refereegranskat)abstract
- Adeno-associated virus vectors (AAV) are reported to have a great potential for gene therapy, however, a major bottleneck for this kind of therapy is the limitation of production capacity. Higher specific AAV vector yield is often reported for adherent cell systems compared to cells in suspension, and a microcarrier-based culture is well established for the culture of anchored cells on a larger scale. The purpose of the present study was to explore how microcarrier cultures could provide a solution for the production of AAV vectors based on the triple plasmid transfection of HEK293T cells in a stirred tank bioreactor. In the present study, cells were grown and expanded in suspension, offering the ease of this type of operation, and were then anchored on microcarriers in order to proceed with transfection of the plasmids for transient AAV vector production. This process was developed in view of a bioreactor application in a 200 mL stirred-tank vessel where shear stress aspects were studied. Furthermore, amenability to a continuous process was studied. The present investigation provided a proof-of-concept of a continuous process based on microcarriers in a stirred-tank bioreactor.
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| 32. |
- Lallo, Elias, et al.
(författare)
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Vanadium Redox Flow Battery Using Aemion((TM)) Anion Exchange Membranes
- 2022
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 10:2
-
Tidskriftsartikel (refereegranskat)abstract
- The vanadium redox flow battery (VRFB) is a promising and commercially available technology that poses advantageous features for stationary energy storage. A key component of the VRFB in terms of cost and system efficiency is the membrane. In recent years, anion exchange membranes (AEMs) have gained interest in VRFB research as they in general exhibit lower vanadium crossover due to a more substantial Donnan exclusion effect. In this study, a low-resistance flow cell was developed and the electrochemical performance of Aemion (TM) anion exchange membranes AF1-HNN5-50-X, AF1-HNN8-50-X and AF1-ENN8-50-X were compared against commonly used cation exchange membranes, Nafion(R) 211 and 212. The VRFB using AF1-ENN8-50-X exhibited superior performance versus Nafion(R) 212 regarding cycling efficiency and rate performance. However, relatively high and comparable capacity losses were observed using both membranes. NMR analysis showed no sign of chemical degradation for AF1-ENN8-50-X by immersion in VO2+ solution for 800 h. Although Aemion (TM) AEMs showed good chemical and electrochemical performance, considerable electrolyte crossover was observed due to high water uptake.
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| 33. |
- Lin, Chang, et al.
(författare)
-
Similarity and Froude Number Similitude in Kinematic and Hydrodynamic Features of Solitary Waves over Horizontal Bed
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:8
-
Tidskriftsartikel (refereegranskat)abstract
- This study presents, experimentally, similarity and Froude number similitude (FNS) in the dimensionless features of two solitary waves propagating over a horizontal bed, using two wave gauges and a high-speed particle image velocimetry (HSPIV). The two waves have distinct wave heights H0 (2.9 and 5.8 cm) and still water depths h0 (8.0 and 16.0 cm) but identical H0/h0 (0.363). Together with the geometric features of free surface elevation and wavelength, the kinematic characteristics of horizontal and vertical velocities, as well as wave celerity, are elucidated. Illustration of the hydrodynamic features of local and convective accelerations are also made in this study. Both similarity and FNS hold true for the dimensionless free surface elevation (FSE), wavelength and celerity, horizontal and vertical velocities, and local and convective accelerations in the horizontal and vertical directions. The similarities and FNSs indicate that gravity dominates and governs the wave kinematics and hydrodynamics.
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| 34. |
- Magnusson, Fredrik, et al.
(författare)
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Dynamic Optimization in JModelica.org
- 2015
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 3:2, s. 471-496
-
Tidskriftsartikel (refereegranskat)abstract
- We present the open-source software framework in JModelica.org for numerically solving large-scale dynamic optimization problems. The framework solves problems whose dynamic systems are described in Modelica, an open modeling language supported by several different tools. The framework implements a numerical method based on direct local collocation, of which the details are presented. The implementation uses the open-source third-party software package CasADi to construct the nonlinear program in order to efficiently obtain derivative information using algorithmic differentiation. The framework is interfaced with the numerical optimizers IPOPT and WORHP for finding local optima of the optimization problem after discretization. We provide an illustrative example based on the Van der Pol oscillator of how the framework is used. We also present results for an industrially relevant problem regarding optimal control of a distillation column.
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| 35. |
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| 36. |
- Mohammadi, Ali, 1983-, et al.
(författare)
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A Critical Review on Advancement and Challengesof Biochar Application in Paddy Fields: Environmental and Life Cycle Cost Analysis
- 2020
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Ingår i: processes. - : MDPI. - 2227-9717. ; 8:10
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Tidskriftsartikel (refereegranskat)abstract
- Paddy fields emit considerable amounts of methane (CH4), which is a potent greenhousegas (GHG) and, thereby, causes significant environmental impacts, even as they generate wealth andjobs directly in the agricultural sector, and indirectly in the food-processing sector. Application ofbiochar in rice production systems will not just help to truncate their carbon footprints, but alsoadd to the bottom-line. In this work, the authors have reviewed the literature on climate change,human health, and economic impacts of using organic residues to make biochar for the additionto croplands especially to rice paddy fields. Biochar-bioenergy systems range in scale from smallhousehold cook-stoves to large industrial pyrolysis plants. Biochar can be purveyed in dierentforms—raw, mineral-enriched, or blended with compost. The review of published environmental lifecycle assessment (E-LCA) studies showed biochar has the potential to mitigate the carbon footprint offarming systems through a range of mechanisms. The most important factors are the stabilization ofthe carbon in the biochar and the generation of recoverable energy from pyrolysis gases produced asco-products with biochar as well as decreased fertiliser requirement and enhanced crop productivity.The quantitative review of E-LCA studies concluded that the carbon footprint of rice produced inbiochar-treated soil was estimated to range from -1.43 to 2.79 kg CO2-eq per kg rice grain, implying asignificant reduction relative to rice produced without a biochar soil amendment. The suppressionof soil-methane emission due to the biochar addition is the dominant process with a negativecontribution of 40–70% in the climate change mitigation of rice production. The review of the lifecycle cost studies on biochar use as an additive in farmlands demonstrated that biochar applicationcan be an economically-feasible approach in some conditions. Strategies like the subsidization ofthe initial biochar capital cost and assignment of a non-trivial price for carbon abatement in futurepricing mechanisms will enhance the economic benefits for the rice farmers.
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| 37. |
- Mohammadi, Ali, 1983-
(författare)
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Overview of the Benefits and Challenges Associated with Pelletizing Biochar
- 2021
-
Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:9, s. 1591-
-
Forskningsöversikt (refereegranskat)abstract
- Biochar can be derived from a wide variety of organic materials including agricultural wastes and residues, animal wastes, municipal solid wastes, pulp and paper mill wastes, and sewage sludge. Its productivity relies on feedstock type and thermochemical conditions of production. Biochar has many application advantages in several fields and has been widely studied in recent years. However, most of these studies are mainly on the powder form of biochar, while its pelleted form is sparsely reported. Even with the reported studies on biochar pellets, there is still lack of knowledge and awareness of the effects of different feedstock on the densification behavior of biochar. The mechanisms of biochar densification, which appear to be sensitive to the conditions predominating during its thermochemical production, are affected by the material from which the biochar is derived. This partly accounts for why biochar pellets have not been widely adopted in various application fields. Therefore, this paper presents an overview of the benefits associated with the use of biochar pellets and discusses the challenges encountered when pelleting biochars that are derived from different feedstock under various carbonization conditions. Research priority areas needed to overcome the challenges are also identified and discussed. The purpose is to contribute to better understanding on biochar pelletization behavior, and to offer insights useful to comprehend some basic principles that may occur in the pelleting process and to ease further and more thorough investigations.
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| 38. |
- Mulenshi, Jane, 1977-, et al.
(författare)
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Characterization and beneficiation options for tungsten recovery from Yxsjöberg historical ore tailings
- 2019
-
Ingår i: Processes. - Basel, Switzerland : MDPI. - 2227-9717. ; 7:12
-
Tidskriftsartikel (refereegranskat)abstract
- Repositories of historical tungsten mining tailings pose environmental risks, but are also potential resources for valuable metals. They still contain large tonnages of useful minerals and metals, reflecting the inefficient extraction methods and/or low metal prices at the time they were mined. The focus of this study is to evaluate the technical viability of reprocessing the tailings to recover some of the contained valuable minerals and metals, as well as reducing the negative environmental impact associated with the tailings. Geometallurgical studies were conducted on drill core samples taken from the Smaltjärnen tailings repository of the closed Yxsjöberg tungsten mine, Sweden. The collected samples were characterized physically, chemically, and mineralogically. Knelson concentrator dry low- and high-intensity magnetic separation methods were tested as potential beneficiation methods. The tailings are dominated by the −600 to +149 µm particles. The highest concentration of tungsten (W) was 0.22% WO3. Using a Knelson concentrator, scheelite (main W mineral) recovery was enhanced, with 75 wt.% tungsten recovered in the 34 wt.% heavy concentrate. Only 1.0 wt.% sulphur (S) reported to the non-magnetic fraction. Based on the findings, a methodology and a preliminary process flowsheet for reprocessing the tailings is proposed.
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| 39. |
- Nilsson, Elna J.K., et al.
(författare)
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Laminar burning velocity of lean methane/air flames under pulsed microwave irradiation
- 2021
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:11
-
Tidskriftsartikel (refereegranskat)abstract
- Laminar burning velocity of lean methane/air flames exposed to pulsed microwave irradiation is determined experimentally as part of an effort to accurately quantify the enhancement resulting from exposure of the flame to pulsed microwaves. The experimental setup consists of a heat flux burner mounted in a microwave cavity, where the microwave has an average power of up to 250 W at an E-field in the range of 350–380 kV/m. Laminar burning velocities for the investigated methane/air flames increase from 1.8 to 12.7% when exposed to microwaves. The magnitude of the enhancement is dependent on pulse sequence (duration and frequency) and the strength of the electric field. From the investigated pulse sequences, and at a constant E-field and average power, the largest effect on the flame is obtained for the longest pulse, namely 50 μs. The results presented in this work are, to the knowledge of the authors, the first direct determination of laminar burning velocity on a laminar stretch-free flame exposed to pulsed microwaves.
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| 40. |
- Oh, J. W., et al.
(författare)
-
Reckoning the Dearth of Bioinformatics in the Arena of Diabetic Nephropathy (DN)-Need to Improvise
- 2020
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 8:7
-
Tidskriftsartikel (refereegranskat)abstract
- Diabetic nephropathy (DN) is a recent rising concern amongst diabetics and diabetologist. Characterized by abnormal renal function and ending in total loss of kidney function, this is becoming a lurking danger for the ever increasing population of diabetics. This review touches upon the intensity of this complication and briefly reviews the role of bioinformatics in the area of diabetes. The advances made in the area of DN using proteomic approaches are presented. Compared to the enumerable inputs observed through the use of bioinformatics resources in the area of proteomics and even diabetes, the existing scenario of skeletal application of bioinformatics advances to DN is highlighted and the reasons behind this discussed. As this review highlights, almost none of the well-established tools that have brought breakthroughs in proteomic research have been applied into DN. Laborious, voluminous, cost expensive and time-consuming methodologies and advances in diagnostics and biomarker discovery promised through beckoning bioinformatics mechanistic approaches to improvise DN research and achieve breakthroughs. This review is expected to sensitize the researchers to fill in this gap, exploiting the available inputs from bioinformatics resources.
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| 41. |
- Patel, Nikesh, et al.
(författare)
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Subspace Based Model Identification for an Industrial Bioreactor : Handling Infrequent Sampling Using Missing Data Algorithms
- 2020
-
Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:12
-
Tidskriftsartikel (refereegranskat)abstract
- This manuscript addresses the problem of modeling an industrial (Sartorius) bioreactor using process data. In the context of the Sartorius Bioreactor, it is important to appropriately address the problem of dealing with a large number of variables, which are not always measured or are measured at different sampling rates, without taking recourse to simpler interpolation- or imputation-based approaches. To this end, a dynamic model for the Sartorius Bioreactor is developed via appropriately adapting a recently presented subspace model identification technique, which in turn uses nonlinear iterative partial least squares (NIPALS) algorithms to gracefully handle the missing data. The other key contribution is evaluating the ability of the identification approach to provide insight into the process by computing interpretable variables such as metabolite rates. The results demonstrate the ability of the proposed approach to model data from the Sartorius Bioreactor.
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| 42. |
- Qian, Jin Yuan, et al.
(författare)
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Effects of a dynamic injection flow rate on slug generation in a cross-junction square microchannel
- 2019
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 7:10
-
Tidskriftsartikel (refereegranskat)abstract
- The injection flow rates of two liquid phases play a decisive role in the slug generation of the liquid-liquid slug flow. However, most injection flow rates so far have been constant. In order to investigate the effects of dynamic injection flow rates on the slug generation, including the slug size, separation distance and slug generation cycle time, a transient numerical model of a cross-junction square microchannel is established. The Volume of Fluid method is adopted to simulate the interface between two phases, i.e., butanol and water. The model is validated by experiments at a constant injection flow rate. Three different types of dynamic injection flow rates are applied for butanol, which are triangle, rectangular and sine wave flow rates. The dynamic injection flow rate cycles, which are related to the constant slug generation cycle time t0, are investigated. Results show that when the cycle of the disperse phase flow rate is larger than t0, the slug generation changes periodically, and the period is influenced by the cycle of the disperse phase flow rate. Among the three kinds of dynamic disperse flow rate, the rectangular wave influences the slug size most significantly, while the triangle wave influences the separation distance and the slug generation time more prominently.
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| 43. |
- Rahman, Moksadur, 1989-, et al.
(författare)
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A review on the modeling, control and diagnostics of continuous pulp digesters
- 2020
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 8:10, s. 1-26
-
Tidskriftsartikel (refereegranskat)abstract
- Being at the heart of modern pulp mills, continuous pulp digesters have attracted much attention from the research community. In this article, a comprehensive review in the area of modeling, control and diagnostics of continuous pulp digesters is conducted. The evolution of research focus within these areas is followed and discussed. Particular effort has been devoted to identifying the state-of-the-art and the research gap in a summarized way. Finally, the current and future research directions in the areas have been analyzed and discussed. To date, digester modeling following the Purdue approach, Kappa number control using model predictive controllers and health index-based diagnostic approaches by utilizing different statistical methods have dominated the field. While the rising research interest within the field is evident, we anticipate further developments in advanced sensors and integration of these sensors for improving model prediction and controller performance; and the exploration of different AI-based approaches will be at the core of future research.
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| 44. |
- Rahman, Moksadur, 1989-, et al.
(författare)
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An Approach for Feedforward Model Predictive Control of Continuous Pulp Digesters
- 2019
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 7:9, s. 602-622
-
Tidskriftsartikel (refereegranskat)abstract
- Kappa number variability at the continuous digester outlet is a major concern for pulp and paper mills. It is evident that the aforementioned variability is strongly linked to the feedstock wood properties, particularly lignin content. Online measurement of lignin content utilizing near-infrared spectroscopy at the inlet of the digester is paving the way for tighter control of the blow-line Kappa number. In this paper, an innovative approach of feedforwarding the lignin content to a model predictive controller was investigated with the help of modeling and simulation studies. For this purpose, a physics-based modeling library for continuous pulp digesters was developed and validated. Finally, model predictive control approaches with and without feedforwarding the lignin measurement were evaluated against current industrial control and proportional-integral-derivative (PID) schemes.
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| 45. |
- Ramesh, Vetukuri
(författare)
-
Effect of Biochar and Microbial Inoculation on P, Fe, and Zn Bioavailability in a Calcareous Soil
- 2022
-
Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- To identify effective ways of increasing the yield of crops grown in nutrient-poor calcareous soils, the combined effects of biochar addition and inoculation with plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) on wheat growth and soil properties were investigated under rhizobox conditions. Measured soil properties included pH, electrical conductivity (EC), organic matter content (OM), the availability of P, Fe, and Zn in the rhizosphere, and the uptake of these elements by plants. Combined biochar addition and microbial inoculation were shown to significantly increase the concentration of available forms of P, Fe, and Zn in the soil when compared to non-biochar treatments. The highest soil pH (7.82) was observed following biochar addition without microbial inoculation. The EC following biochar addition and PGPR inoculation was significantly higher than the other treatments, and the soil OM content was highest when combining AMF inoculation with biochar addition. The available P content after AMF inoculation combined with biochar addition was 27.81% higher than the control conditions, and AMF inoculation increased Fe and Zn bioavailability by factors of 2.38 and 1.29, respectively, when combined with biochar addition relative to AMF inoculation alone. The simultaneous biochar addition and PGPR inoculation significantly increased P uptake by the plants. The highest shoot Fe and Zn uptake rates were observed after a simultaneous application of biochar and PGPR inoculation. Under these conditions, shoot uptake was higher than seen when combining biochar addition with AMF inoculation by factors of 1.64 and 1.21, respectively. In general, it can be concluded that combining inoculation with growth-promoting bacteria and biochar addition can effectively improve nutrient availability to plant and soil conditions.
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| 46. |
- Ramesh, Vetukuri, et al.
(författare)
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Harnessing the Potential of Symbiotic Endophytic Fungi and Plant Growth-Promoting Rhizobacteria to Enhance Soil Quality in Saline Soils
- 2021
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Soil salinity is one of the most important abiotic stresses limiting crop growth and production worldwide. Some microorganisms can improve the plants' tolerance to salinity. For this purpose, a greenhouse experiment was performed to understand the influence of various microorganisms on soil biological indices and wheat growth under different saline conditions. The factors varied in the experiment were the microbial treatment (rhizobacteria, mycorrhizal fungi, endophytic fungus, and control) and salinity stress (0.5, 8, and 14 dS m(-1)). Rhizobacteria were isolated from saline soils, but the fungi were prepared from a microbial bank. Overall, ten isolates were purified, and three with promising growth-promoting properties were identified using phenotypic and molecular methods. The selected isolates belonged to the genera Pseudomonas (P. aeruginosa Ur83 and P. fluorescens Ur67) and Stenotrophomonas (S. maltophilia Ur52). Soil quality indices were found to decrease with increasing salinity, but inoculation with microorganisms alleviated this decline. Inoculation with plant growth-promoting rhizobacteria (PGPRs) increased basal respiration, substrate-induced respiration, microbial biomass carbon, acid and alkaline phosphatase activities, and carbon availability by factors of 1.37, 1.27, 1.83, 3.07, 1.29, and 1.11, respectively. These results show that inoculation with symbiotic microorganisms can improve agricultural soil quality under saline conditions and may thus be valuable in agriculture.
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| 47. |
- Roques, Jonathan, 1985, et al.
(författare)
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Effects of Recirculating Aquaculture System Wastewater on Anammox Performance and Community Structure
- 2021
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Recirculating aquaculture systems (RAS) are good candidates for the sustainable development of the aquaculture sector. A current limitation of RAS is the production and accumulation of nitrogenous waste, which could affect fish health. We investigated the potential of the anaerobic ammonia oxidation (anammox) process to treat marine wastewater from a cold-water RAS. We show that the marine anammox bacteria Candidatus Scalindua is a promising candidate. However, its activity was affected by unknown compounds in the RAS wastewater and/or the sub-optimum of essential trace elements (TEs). Anammox activity dropped to 2% and 13% in NH4+ and NO2- removal, respectively, when nitrate-rich RAS wastewater was used as a medium in the absence of TE supplementation. A TE supplementation was added to the RAS wastewater in a subsequent phase, and a recovery in anammox activity was shown (25% and 24% in NH4+ and NO2- removal, respectively). Future studies need to identify the unknown factor and determine the specific needs regarding TE for optimal RAS wastewater treatment by Candidatus Scalindua
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| 48. |
- Safaric, Luka, 1988-, et al.
(författare)
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A Comparative Study of Biogas Reactor Fluid Rheology : Implications for Mixing Profile and Power Demand
- 2019
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Ingår i: Processes. - Basel, Switzerland : MDPI. - 2227-9717. ; 7:10
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Tidskriftsartikel (refereegranskat)abstract
- Anaerobic digestion (AD) is an established process for integrating waste management with renewable energy and nutrient recovery. Much of the research in this field focuses on the utilisation of new substrates, yet their effects on operational aspects such as fluid behaviour and power requirement for mixing are commonly overlooked, despite their importance for process optimisation. This study analysed rheological characteristics of samples from 21 laboratory-scale continuous stirred-tank biogas reactors (CSTBRs) digesting a range of substrates, in order to evaluate substrate effect on mixing efficiency and power demand through computational fluid dynamics (CFD). The results show that substrate and process parameters, such as solids content and organic loading, all have a significant effect on CSTBR fluid rheology. The correlation levels between rheological and process parameters were different across substrates, while no specific fluid behaviour patterns could be associated with substrate choice. Substrate should thus be considered an equally important rheology effector as process parameters. Additional substrate-related parameters should be identified to explain the differences in correlations between rheological and process parameters across substrate groups. The CFD modelling revealed that the rheology differences among the AD processes have significant implications for mixing efficiency and power demand of the CSTBRs, highlighting the importance of considering the substrate-induced effects on CSTBR rheology before including a new substrate.
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| 49. |
- Saffari Pour, Mohsen, 1987-, et al.
(författare)
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Numerical Investigation of a Portable Incinerator : A Parametric Study
- 2020
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Ingår i: Processes. - : MDPI AG. - 2227-9717. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- The application of incinerators for the municipal solid waste (MSW) is growing due to the ability of such instruments to produce energy and, more specifically, reduce waste volume. In this paper, a numerical simulation of the combustion process with the help of the computational fluid dynamics (CFD) inside a portable (mobile) incinerator has been proposed. Such work is done to investigate the most critical parameters for a reliable design of a domestic portable incinerator, which is suitable for the Iranian food and waste culture. An old design of a simple incinerator has been used to apply the natural gas (NG), one of the available cheap fossil fuels in Iran. After that, the waste height, place of the primary burner, and the flow rate of the cooling air inside the incinerator, as the main parameters of the design, are investigated. A validation is also performed for the mesh quality test and the occurrence of the chemical reactions near the burner of the incinerator. Results proved that the numerical results have less than 5% error compared to the previous experimental and numerical approaches. In addition, results show that by moving the primary burner into the secondary chamber of the incinerator, the temperature and the heating ability of the incinerator could be affected dramatically. Moreover, it has been found that by increasing the flow rate of the cooling air inside the incinerator to some extent, the combustion process is improved and, on the other hand, by introducing more cooling air, the evacuation of the hazardous gases from the exhaust is also improved.
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| 50. |
- Salmi, Tapio, et al.
(författare)
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A Robust Method for the Estimation of Kinetic Parameters for Systems Including Slow and Rapid Reactions - From Differential-Algebraic Model to Differential Model
- 2020
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Reliable estimation of kinetic parameters in chemical systems comprising both slow and rapid reaction steps and rapidly reacting intermediate species is a difficult differential-algebraic problem. Consequently, any conventional approach easily leads to serious convergence and stability problems during the parameter estimation. A robust method is proposed to surmount this dilemma: the system of ordinary differential equations and nonlinear algebraic equations is converted to ordinary differential equations, which are solved in-situ during the parameter estimation. The approach was illustrated with two generic examples and an example from green chemistry: synthesis of dimethyl carbonate from carbon dioxide and methanol.
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