Статті в журналах з теми "From lab to full scale design"
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1
Flapper, T. G., N. J. Ashbolt, A. T. Lee, and M. O'Neill. "From the lab to full-scale SBR operation: treating high strength and variable industrial wastewaters." Water Science and Technology 43, no. 3 (February 1, 2001): 347–54. http://dx.doi.org/10.2166/wst.2001.0156.
Повний текст джерелаАнотація:
This paper describes the path taken from client objectives through laboratory studies and detailed design to full-scale SBR operation and current research. Conventional municipal design principles have often been used to develop treatment processes for industrial wastewaters. The use of scientific trials to test design criteria offers the client a “tailor made” design fit for their particular wastewater character. In this project, a waste management company wished to upgrade their physical-chemical treatment plant to incorporate a biological reactor for treating a range of industrial wastewaters. Laboratory-scale trials were undertaken to determine appropriate design criteria for a full-scale biological process. These laboratory studies indicated that conventional design criteria were not appropriate and that a SBR configuration was optimal compared with an IDAR configuration. It was also found that a novel fungal:bacterial mixed liquor consortium developed, resulting in good effluent quality and settling properties. The treatment plant was able to be constructed and operational within a tight timeframe and budget, allowing the client to take advantage of a commercial opportunity. The plant has been operating since 1997 and meets its discharge conditions. By combining scientific studies with engineering principles, the end-user obtained a complete treatment plant to meet their specific needs. A further benefit of the laboratory trials is current research into the development of a fungal:bacterial SBR to treat industrial wastewaters. This offers ongoing knowledge to the operational full-scale SBR.
2
Malmqvist, Åsa, Lars Gunnarsson, and Christer Torstenon. "Lab and pilot scale tests as tools for upgrading - comparison with full scale results." Water Science and Technology 37, no. 9 (May 1, 1998): 25–31. http://dx.doi.org/10.2166/wst.1998.0336.
Повний текст джерелаАнотація:
Parameters such as hydraulic retention time, organic load, maximum COD removal, sludge characteristics and optimal nutrient dosage can be determined by simulation in small scale models of the chosen process. Laboratory tests are the natural first step when considering upgrading, or designing a new, biological treatment plant. The potential for a biological treatment can be examined at a low cost and within a minimum of time, often through parallel testing of different treatment methods. Once a suitable process configuration has been found, lab scale tests may well be used for optimizing the process and obtaining design data, thus minimizing the need for more expensive tests in larger scale. The principal reason for a pilot plant test is the possibility to investigate natural variations in wastewater composition and the effect this will have on process stability. The use of laboratory and pilot scale tests is here illustrated by the work carried out prior to the upgrading of the treatment plant at Nyboholm paper mill. A description of the upgraded full scale installation consisting of both chemical treatment and a suspended-carrier biofilm process is included and a comparison between results from lab, pilot and full scale treatment is made.
3
Krause, S., P. Cornel, and M. Wagner. "Comparison of different oxygen transfer testing procedures in full-scale membrane bioreactors." Water Science and Technology 47, no. 12 (June 1, 2003): 169–76. http://dx.doi.org/10.2166/wst.2003.0643.
Повний текст джерелаАнотація:
Membrane bioreactors (MBRs) for wastewater treatment offer the advantage of a complete removal of solids from the effluent. The secondary clarifier is replaced by a membrane filtration and therefore high biomass concentrations (MLSS) in the reactor are possible. The design of the aeration system is vital for an energy efficient operation of any wastewater treatment plant. Hence the exact measurement of oxygen transfer rates (OTR) and α-values is important. For MBRs these values reported in literature differ considerably. The OTR can be measured using non-steady state methods or using the off-gas method. The non-steady state methods additionally require the determination of the respiration rate (oxygen uptake rate ≡ OUR), which usually is measured in lab scale units. As there are differences of OUR between lab scale and full scale measurements, off-gas tests (which do not require an additional respiration test) were performed in order to compare both methods at high MLSS concentrations. Both methods result in the same average value of OTR. Due to variations in loading and wastewater composition variations of OTR in time can be pointed out using the off-gas method. For the first time a comparison of different oxygen transfer tests in full scale membrane bioreactors is presented.
4
Nywening, J. P., H. Zhou, and H. Husain. "Comparison of mixed liquor filterability measured with bench and pilot-scale membrane bioreactors." Water Science and Technology 56, no. 6 (September 1, 2007): 155–62. http://dx.doi.org/10.2166/wst.2007.644.
Повний текст джерелаАнотація:
Parallel experimental tests to measure mixed liquor filterability for submerged membrane bioreactors were conducted over a six month period using three ZW-500 pilot plants and a ZW-10 lab-scale filterability apparatus. Non-air sparged conditions during the tests yielded operation behaviour that was equivalent to dead-end filtration. The fouling resistance increased linearly with the intercepted mass until a critical point was reached at which point significant cake compression was induced and the resistance began to increase exponentially. Although the point of cake compression appears to be dependent on the membrane module design, similar resistance per unit solid mass intercepted per unit area (Rmass) values were observed when the same mixed liquor was filtered. Coupled with the established correlation between the Rmass and the critical flux, it is suggested that the filterability test results from a side-stream, lab-scale module may be used to predict fouling potential in a full scale MBR wastewater treatment system without interrupting the full-scale MBR operation.
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Miranda, Margarida, Cláudia Veloso, Catarina Cardoso, and Carla Vitorino. "From Lab to Upscale—Boosting Formulation Performance through In Vitro Technologies." Proceedings 78, no. 1 (December 1, 2020): 35. http://dx.doi.org/10.3390/iecp2020-08674.
Повний текст джерелаАнотація:
Pre-stability studies carried out throughout the development of a diclofenac emulgel formulation have shown a clear decrease in the drug release rate. In order to address the root-cause associated with this phenomena, product historical data were retrieved and analyzed following a retrospective Quality by Design (rQbD) approach. The quality target product profile (QTPP) was established, and risk assessment tools were used to identify the most relevant parameters affecting formulation performance. These consisted in (i) mixing time, (ii) sodium hydroxide content and (iii) carbopol grade. Following a 23 full factorial design, the pH, viscosity, in vitro release rate and cumulative amount of drug released at the end of the release experiment were selected as responses to statistically model the available data. It was observed that higher sodium hydroxide concentrations induce a decrease in viscosity, consequently resulting in a superior pharmaceutical performance. Moreover, as a secondary effect, a lower carbopol viscosity yields lower release outputs. The estimated models were used to define a feasible working region, which was further confirmed at an industrial scale. This work highlights the use of rQbD principles to achieve a greater product understanding. By doing so, specific strategies can be applied to product manufacture in order to consistently meet QTPP requirements.
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Huang, Xing, Tsung-Yi Ho, Wenzhong Guo, Bing Li, Krishnendu Chakrabarty, and Ulf Schlichtmann. "Computer-aided Design Techniques for Flow-based Microfluidic Lab-on-a-chip Systems." ACM Computing Surveys 54, no. 5 (June 2021): 1–29. http://dx.doi.org/10.1145/3450504.
Повний текст джерелаАнотація:
As one of the most promising lab-on-a-chip systems, flow-based microfluidic biochips are being increasingly used for automatically executing various laboratory procedures in biology and biochemistry, such as enzyme-linked immunosorbent assay, point-of-care diagnosis, and so on. As manufacturing technology advances, the characteristic dimensions of biochip systems keep shrinking, and tens of thousands of microvalves can now be integrated into a coin-sized microfluidic platform, making the conventional manual-based chip design no longer applicable. Accordingly, computer-aided design (CAD) of microfluidics has attracted considerable research interest in the EDA community over the past decade. This review article presents recent advances in the design automation of biochips, involving CAD techniques for architectural synthesis, wash optimization, testing, fault diagnosis, and fault-tolerant design. With the help of these CAD tools, chip designers can be released from the burden of complex, large-scale design tasks. Meanwhile, new chip architectures can be explored automatically to open new doors to meet requirements from future large-scale biological experiments and medical diagnosis. We discuss key trends and directions for future research that are related to enable microfluidics to reach its full potential, thus further advancing the development and progression of the microfluidics industry.
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Sjostrom, Sharon, and Constance Senior. "Pilot testing of CO2 capture from a coal-fired power plant—Part 2: Results from 1-MWe pilot tests." Clean Energy 4, no. 1 (March 2020): 12–25. http://dx.doi.org/10.1093/ce/zkz034.
Повний текст джерелаАнотація:
Abstract Using a 1-MWe slipstream pilot plant, solid-sorbent-based post-combustion CO2 capture was tested at a coal-fired power plant. Results from pilot testing were used to develop a preliminary full-scale commercial design. The sorbent selected for pilot-scale evaluation during this project consisted of an ion-exchange resin that incorporated amines covalently bonded to the substrate. A unique temperature-swing-absorption (TSA) process was developed that incorporated a three-stage fluidized-bed adsorber integrated with a single-stage fluidized-bed regenerator. Overall, following start-up and commissioning challenges that are often associated with first-of-a-kind pilots, the pilot plant operated as designed and expected, with a few key exceptions. The two primary exceptions were associated with: (i) handling characteristics of the sorbent, which were sufficiently different at operating temperature than at ambient temperature when design specifications were established with lab-scale testing; and (ii) CO2 adsorption in the transport line between the regenerator and adsorber that preloaded the sorbent with CO2 prior to entering the adsorber. Results from the pilot programme demonstrate that solid-sorbent-based post-combustion capture can be utilized to achieve 90% CO2 capture from coal-fired power plants.
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Ali, Mohammad, Li-Yuan Chai, Chong-Jian Tang, Ping Zheng, Xiao-Bo Min, Zhi-Hui Yang, Lei Xiong, and Yu-Xia Song. "The Increasing Interest of ANAMMOX Research in China: Bacteria, Process Development, and Application." BioMed Research International 2013 (2013): 1–21. http://dx.doi.org/10.1155/2013/134914.
Повний текст джерелаАнотація:
Nitrogen pollution created severe environmental problems and increasingly has become an important issue in China. Since the first discovery of ANAMMOX in the early 1990s, this related technology has become a promising as well as sustainable bioprocess for treating strong nitrogenous wastewater. Many Chinese research groups have concentrated their efforts on the ANAMMOX research including bacteria, process development, and application during the past 20 years. A series of new and outstanding outcomes including the discovery of new ANAMMOX bacterial species (Brocadia sinica), sulfate-dependent ANAMMOX bacteria (Anammoxoglobus sulfate andBacillus benzoevorans), and the highest nitrogen removal performance (74.3–76.7 kg-N/m3/d) in lab scale granule-based UASB reactors around the world were achieved. The characteristics, structure, packing pattern and floatation mechanism of the high-rate ANAMMOX granules in ANAMMOX reactors were also carefully illustrated by native researchers. Nowadays, some pilot and full-scale ANAMMOX reactors were constructed to treat different types of ammonium-rich wastewater including monosodium glutamate wastewater, pharmaceutical wastewater, and leachate. The prime objective of the present review is to elucidate the ongoing ANAMMOX research in China from lab scale to full scale applications, comparative analysis, and evaluation of significant findings and to set a design to usher ANAMMOX research in culmination.
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Basnayake, B. F. A. "Simulation of Lab-scale Leachate Treatment Bioreactor with Application of Logistic Growth Equation for Determining Design and Operational Parameters." International Journal of Scientific & Engineering Research 8, no. 1 (January 25, 2017): 1061–70. http://dx.doi.org/10.14299/ijser.2017.01.021.
Повний текст джерелаАнотація:
A laboratory scale Leachate Treatment Bioreactor (LTB) was needed to determine the optimum design and operational parameters because of poor performance of a full scale unit. In order to increase the lifespan of LTB, coconut comb and rubber tyres were included in the partially decomposed Municipal Solid Waste (MSW) as biofilter material inside the reactor. A composite liner of clay and waste polythene was used to mineralize excess inorganic compounds. The parameter reductions were from 26,000 mg/L to 6,832 mg/L of Total Solids (TS), 6,230 mg/L to 2,930 mg/L of Total Disolved Solids (TDS), 12,000 mg/L to 1182.6 mg/L of Volatile Solids (VS), 14,000 mg/L to 4,410 mg/L of Total Fixed Solids (TFS) and 29,700 mg/L to 3,000 mg/L of Biochemical Oxygen Demand (BOD). The kinetic analysis using the logistic growth equation showed cyclic events and the application of separating the growth and decay of microbes based on the Total Fixed Solids (TFS) gave a mineralization rate of 1.83 x 102 kg /m3 of leachate/m height of LTB /day for up scaling.
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Kasten, Georgia, Íris Duarte, Maria Paisana, Korbinian Löbmann, Thomas Rades, and Holger Grohganz. "Process Optimization and Upscaling of Spray-Dried Drug-Amino acid Co-Amorphous Formulations." Pharmaceutics 11, no. 1 (January 9, 2019): 24. http://dx.doi.org/10.3390/pharmaceutics11010024.
Повний текст джерелаАнотація:
The feasibility of upscaling the formulation of co-amorphous indomethacin-lysine from lab-scale to pilot-scale spray drying was investigated. A 22 full factorial design of experiments (DoE) was employed at lab scale. The atomization gas flow rate (Fatom, from 0.5 to 1.4 kg/h) and outlet temperature (Tout, from 55 to 75 °C) were chosen as the critical process parameters. The obtained amorphization, glass transition temperature, bulk density, yield, and particle size distribution were chosen as the critical quality attributes. In general, the model showed low Fatom and high Tout to be beneficial for the desired product characteristics (a co-amorphous formulation with a low bulk density, high yield, and small particle size). In addition, only a low Fatom and high Tout led to the desired complete co-amorphization, while a minor residual crystallinity was observed with the other combinations of Fatom and Tout. Finally, upscaling to a pilot scale spray dryer was carried out based on the DoE results; however, the drying gas flow rate and the feed flow rate were adjusted to account for the different drying chamber geometries. An increased likelihood to achieve complete amorphization, because of the extended drying chamber, and hence an increased residence time of the droplets in the drying gas, was found in the pilot scale, confirming the feasibility of upscaling spray drying as a production technique for co-amorphous systems.
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Kim, Jeong Myeong, Hyo Jung Lee, Dae Sung Lee, Kangseok Lee, and Che Ok Jeon. "Identification of a novel subgroup of uncultured gammaproteobacterial glycogen-accumulating organisms in enhanced biological phosphorus removal sludge." Microbiology 157, no. 8 (August 1, 2011): 2287–96. http://dx.doi.org/10.1099/mic.0.047779-0.
Повний текст джерелаАнотація:
The presence of glycogen-accumulating organisms (GAO) has been hypothesized to be a cause of deterioration in enhanced biological phosphorus removal (EBPR) processes due to their abilities to out-compete polyphosphate-accumulating organisms (PAO). Based on 16S rRNA gene sequences, new members of uncultured gammaproteobacterial GAO (GB) were identified from sludge samples of a lab-scale sequencing batch reactor used for EBPR. The new GB formed a phylogenetic lineage (GB8) clearly distinct from the previously reported seven GB subgroups. Because the new GB8 members were not targeted by the known fluorescence in situ hybridization (FISH) oligonucleotide probes, a GB8-specific FISH probe (GB429) and a new FISH probe (GB742) targeting all eight GB subgroups were designed, and the phenotypic properties of the new GB8 members were investigated. FISH and microautoradiography approaches showed that GB429-targeted cells (GB8) were large coccobacilli (2–4 µm in size) with the ability to take up acetate under anaerobic conditions, but unable to accumulate polyphosphate under the subsequent aerobic conditions, consistent with in situ phenotypes of GB. FISH analyses on several sludge samples showed that members of GB8 were commonly detected as the majority of GB in lab- and full-scale EBPR processes. In conclusion, this study showed that members of GB8 could be a subgroup of GB with an important role in EBPR deterioration. Designs of FISH probes which hybridize with broader GB subgroups at different hierarchical levels will contribute to studies of the distributions and ecophysiologies of GB in lab- or full-scale EBPR plants.
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Tokarev, Mikhail. "A Double-Bed Adsorptive Heat Transformer for Upgrading Ambient Heat: Design and First Tests." Energies 12, no. 21 (October 23, 2019): 4037. http://dx.doi.org/10.3390/en12214037.
Повний текст джерелаАнотація:
A full scale lab prototype of an adsorptive heat transformer (AHT), consisting of two adsorbers, an evaporator, and a condenser, was designed and tested in subsequent cycles of heat upgrading. The composite LiCl/SiO2 was used as an adsorbent with methanol as an adsorbtive substance under boundary temperatures of TL/TM/TH = −30/20/30 °C. Preliminary experiments demonstrated the feasibility of the tested AHT in continuous heat generation, with specific power output of 520 W/kg over 1–1.5 h steady-state cycling. The formal and experimental thermal efficiency of the tested rig were found to be 0.5 and 0.44, respectively. Although the low potential heat to be upgraded was available for free from a natural source, the electric efficiency of the prototype was found to be as high as 4.4, which demonstrates the promising potential of the “heat from cold” concept. Recommendations for further improvements are also outlined and discussed in this paper.
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Balemans, Sophie, Siegfried E. Vlaeminck, Elena Torfs, Leonie Hartog, Laura Zaharova, Usman Rehman, and Ingmar Nopens. "The Impact of Local Hydrodynamics on High-Rate Activated Sludge Flocculation in Laboratory and Full-Scale Reactors." Processes 8, no. 2 (January 21, 2020): 131. http://dx.doi.org/10.3390/pr8020131.
Повний текст джерелаАнотація:
High rate activated sludge (HRAS) processes have a high potential for carbon and energy recovery from sewage, yet they suffer frequently from poor settleability due to flocculation issues. The process of flocculation is generally optimized using jar tests. However, detailed jar hydrodynamics are often unknown, and average quantities are used, which can significantly differ from the local conditions. The presented work combined experimental and numerical data to investigate the impact of local hydrodynamics on HRAS flocculation for two different jar test configurations (i.e., radial vs. axial impellers at different impeller velocities) and compared the hydrodynamics in these jar tests to those in a representative section of a full scale reactor using computational fluid dynamics (CFD). The analysis showed that the flocculation performance was highly influenced by the impeller type and its speed. The axial impeller appeared to be more appropriate for floc formation over a range of impeller speeds as it produced a more homogeneous distribution of local velocity gradients compared to the radial impeller. In contrast, the radial impeller generated larger volumes (%) of high velocity gradients in which floc breakage may occur. Comparison to local velocity gradients in a full scale system showed that also here, high velocity gradients occurred in the region around the impeller, which might significantly hamper the HRAS flocculation process. As such, this study showed that a model based approach was necessary to translate lab scale results to full scale. These new insights can help improve future experimental setups and reactor design for improved HRAS flocculation.
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Bopape, Mokgadi F., Tim Van Geel, Abhishek Dutta, Bart Van der Bruggen, and Maurice Stephen Onyango. "Numerical Modelling Assisted Design of a Compact Ultrafiltration (UF) Flat Sheet Membrane Module." Membranes 11, no. 1 (January 14, 2021): 54. http://dx.doi.org/10.3390/membranes11010054.
Повний текст джерелаАнотація:
The increasing adoption of ultra-low pressure (ULP) membrane systems for drinking water treatment in small rural communities is currently hindered by a limited number of studies on module design. Detailed knowledge on both intrinsic membrane transport properties and fluid hydrodynamics within the module is essential in understanding ULP performance prediction, mass transfer analysis for scaling-up between lab-scale and industrial scale research. In comparison to hollow fiber membranes, flat sheet membranes present certain advantages such as simple manufacture, sheet replacement for cleaning, moderate packing density and low to moderate energy usage. In the present case study, a numerical model using computational fluid dynamics (CFD) of a novel custom flat sheet membrane module has been designed in 3D to predict fluid flow conditions. The permeate flux through the membrane decreased with an increase in spacer curviness from 2.81 L/m2h for no (0%) curviness to 2.73 L/m2h for full (100%) curviness. A parametric analysis on configuration variables was carried out to determine the optimum design variables and no significant influence of spacer inflow or outflow thickness on the fluid flow were observed. The numerical model provides the necessary information on the role of geometrical and operating parameters for fabricating a module prototype where access to technical expertise is limited.
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Bortolini, Marco, Maurizio Faccio, Francesco Gabriele Galizia, Mauro Gamberi, and Francesco Pilati. "Design, engineering and testing of an innovative adaptive automation assembly system." Assembly Automation 40, no. 3 (February 29, 2020): 531–40. http://dx.doi.org/10.1108/aa-06-2019-0103.
Повний текст джерелаАнотація:
Purpose Industry 4.0 emerged as the Fourth Industrial Revolution aiming at achieving higher levels of operational efficiency, productivity and automation. In this context, manual assembly systems are still characterized by high flexibility and low productivity, if compared to fully automated systems. Therefore, the purpose of this paper is to propose the design, engineering and testing of a prototypal adaptive automation assembly system, including greater levels of automation to complement the skills and capabilities of human workers. Design/methodology/approach A lab experimental field-test is presented comparing the assembly process of a full-scale industrial chiller with traditional and adaptive assembly system. Findings The analysis shows relevant benefits coming from the adoption of the adaptive automation assembly system. In particular, the main findings highlight improvements in the assembly cycle time and productivity, as well as reduction of the operator’s body movements. Practical implications The prototype is applied in an Italian mid-size industrial company, confirming its impact in terms of upgrades of the assembly system flexibility and productivity. Thus, the research study proposed in this paper provides valuable knowledge to support companies and industrial practitioners in the shift from traditional to advanced assembly systems matching current industrial and market features. Originality/value This paper expands the lacking research on adaptive automation assembly systems design proposing an innovative prototype able to real-time reconfigure its structure according to the product to work, e.g. work cycle, and the operator features.
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Rahmani, Fatemeh, Payam Niknejad, Tanushree Agarwal, and Mohammadreza Barzegaran. "Gallium Nitride Inverter Design with Compatible Snubber Circuits for Implementing Wireless Charging of Electric Vehicle Batteries." Machines 8, no. 3 (September 15, 2020): 56. http://dx.doi.org/10.3390/machines8030056.
Повний текст джерелаАнотація:
High-frequency wireless power transfer (WPT) technology provides superior compatibility in the alignment with various WPT standards. However, high-efficiency and compact single-phase power switching systems with ideal snubber circuits are required for maximum power transfer capability. This research aims to develop an inverter using Gallium Nitride (GaN) power transistors, optimized RCD (resistor/capacitor/diode) snubber circuits, and gate drivers, each benefitting WPT technology by reducing the switching and conduction loss in charging electric vehicle batteries. A full-bridge GaN inverter was simulated and instituted as part of the wireless charging circuit design. The RCD circuits were adjusted by transferring maximum power from the power supply to the transmitter inductor. For verification of the simulated output, lab-scale experiments were implemented for two half-bridges controlled by gate drivers with corresponding snubber circuits. After authenticating the output results, the GaN inverter was tested with an input range of 30 V to deduce the success of charging electric vehicle batteries within an efficient time frame. The developed inverter, at 80 kHz frequency, was applied in place of a ready-to-use evaluation board, fully reducing less harmonic distortion and greatly increasing WPT system efficiency (~93%). In turn, the designed GaN inverter boasts considerable energy savings, resulting in a more cost-effective solution for manufacturers.
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Rybicki, Stanisław M., and Małgorzata Cimochowicz-Rybicka. "Dimensioning of Digestion Chamber for Upgrading of Gas Recovery at Wastewater Treatment Plant." Archives of Environmental Protection 39, no. 4 (December 1, 2013): 105–12. http://dx.doi.org/10.2478/aep-2013-0038.
Повний текст джерелаАнотація:
Abstract The paper describes practical results of four-year laboratory studies completed to estimate technically feasible conditions of upgrading an existing sludge disposal system. A minimization of sludge mass and volume together with an energy recovery improvement were main goals of these activities. The way from lab studies and simulations to full scale investments has been shown with a special emphasis on application of respirometric procedure being applied by authors. Proposed was authors’ procedure for an estimation of a digestion time prediction for sludge of specific composition. Investigations completed at existing wastewater treatment plant resulted in practical implementation to be used during the design of upgrading and extension of the digestion and energy recovery system at the plant. It was proved that proposed changes provide close to optimum conditions for process performance and the application of proposed calculation procedures was adopted by design team
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Eroglu, V., I. Ozturk, H. A. San, and I. Demir. "Comparative Evaluation of Treatment Alternatives for Wastewaters from an Edible Oil Refining Industry." Water Science and Technology 22, no. 9 (September 1, 1990): 225–34. http://dx.doi.org/10.2166/wst.1990.0086.
Повний текст джерелаАнотація:
The aim of this study was to investigate the treatment alternatives for high-strength acid waters from an edible oil refinery and to determine an appropriate treatment system. The study was conducted in three stages: waste characterization, treatability studies and wastewater treatment system design. Based on preliminary lab-scale flotation experiments a full-scale Dissolved Air Flotation (DAF) plant was constructed. The removal of fatty materials (FM) was more than 80% without using any chemical reagent in the DAF unit. Physico-chemical treatability studies were conducted by using FeCl3, A12(SO4)3 and Ca(OH)2 as coagulants. Aerobic treatability experiments were carried out by means of an insitu pilot-scale activated sludge (AS) unit with a volume of 240 1. A BOD5 removal of 85% and FM removal of 95% were achieved for the organic loading rate (OLR) of 0.45 kg BOD5kg VSS.d. The biological sludge had an excellent settling property with a sludge volume index (SVI) of 55 to 74 ml/g. Anaerobic sulphate removal kinetics was also investigated as a comparable alternative to physico-chemical treatment both in a pilot upflow anaerobic sludge blanket reactor (UASBR) and anaerobic filter (AF). Anaerobic treatability experiments showed that the linearized second-order substrate removal kinetics could be used to explain the anaerobic sulphate removal from acid waters of edible oil refineries. The maximum sulphate removal efficiency of the AF was about 60% for a hydraulic retention time of two days.
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Capurso, Giovanni, Julian Jepsen, José M. Bellosta von Colbe, Claudio Pistidda, Oliver Metz, Deniz Yigit, Hu Jun Cao, et al. "Engineering Solutions in Scale-Up and Tank Design for Metal Hydrides." Materials Science Forum 941 (December 2018): 2220–25. http://dx.doi.org/10.4028/www.scientific.net/msf.941.2220.
Повний текст джерелаАнотація:
A holistic approach is required for the development of materials and systems for hydrogen storage, embracing all the different steps involved in a successful advance of the technology. The several engineering solutions presented in this work try to address the technical challenges in synthesis and application of solid-state hydrogen storage materials, mainly metal hydride based compounds. Moving from the synthesis of samples in lab-scale to the production of industrial sized batches a novel process development is required, including safety approaches (for hazardous powders), and methods to prevent the contamination of sensitive chemicals. The reduction of overall costs has to be addressed as well, considering new sources for raw materials and more cost-efficient catalysts. The properties of the material itself influence the performances of the hydride in a pilot storage tank, but the characteristics of the system itself are crucial to investigate the reaction limiting steps and overcome hindrances. For this, critical experiments using test tanks are needed, learning how to avoid issues as material segregation or temperature gradients, and optimizing the design in the aspects of geometry, hull material, and test station facilities. The following step is a useful integration of the hydrogen storage system into real applications, with other components like fuel cells or hydrogen generators: these challenging scenarios provide insights to design new experiments and allow stimulating demonstrations.
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Valsalakumar, Sreeram, Anurag Roy, Tapas K. Mallick, Justin Hinshelwood, and Senthilarasu Sundaram. "An Overview of Current Printing Technologies for Large-Scale Perovskite Solar Cell Development." Energies 16, no. 1 (December 24, 2022): 190. http://dx.doi.org/10.3390/en16010190.
Повний текст джерелаАнотація:
The power conversion efficiencies (PCEs) of Perovskite solar cells (PSCs) have seen significant performance improvements between 2012 and 2022. PSCs have excellent optoelectronic properties and can be built using low-cost materials. In order to compete with first-generation photovoltaic technologies, it will be necessary to scale up production. This review article explores the advancements in several scalable perovskite deposition techniques, including recent developments in the fabrication of high-quality perovskite film, their stabilities and commercialization status. Several scalable deposition techniques are discussed, including user-friendly solution-techniques (spin coating, slot die coating, etc.), vapour-assisted deposition approaches in the laboratory and full-scale commercial applications. The aforementioned deposition techniques have advantages compared to deposition techniques based on cost, effective mask-less patterning and unparalleled-design freedom. Other potential advantages include optimal use of materials, scalability, contactless deposition in high-resolution and a rapid transformation from small laboratory-scale work to large industrial-scale roll-to-roll production. Most recent technological advancements and structural developments relate to long-term thermal stability and moisture resistance. Many of the developments are still in the evolving field of lab-scale devices. The improvement roadmap and commercialization aspects of PSC manufacture involve two significant milestones: bridging the gap between the performance characteristics of small-scale and large-scale devices and the scalable printing techniques for all the layers in the device.
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Douillet, Camille, Marc Nicodeme, Loïc Hermant, Vanessa Bergeron, Fabien Guillemot, Jean-Christophe Fricain, Hugo Oliveira, and Mikael Garcia. "From local to global matrix organization by fibroblasts: a 4D laser-assisted bioprinting approach." Biofabrication 14, no. 2 (January 24, 2022): 025006. http://dx.doi.org/10.1088/1758-5090/ac40ed.
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Abstract Fibroblasts and myofibroblasts play a central role in skin homeostasis through dermal organization and maintenance. Nonetheless, the dynamic interactions between (myo)fibroblasts and the extracellular matrix (ECM) remain poorly exploited in skin repair strategies. Indeed, there is still an unmet need for soft tissue models allowing to study the spatial-temporal remodeling properties of (myo)fibroblasts. In vivo, wound healing studies in animals are limited by species specificity. In vitro, most models rely on collagen gels reorganized by randomly distributed fibroblasts. But biofabrication technologies have significantly evolved over the past ten years. High-resolution bioprinting now allows to investigate various cellular micropatterns and the emergent tissue organizations over time. In order to harness the full dynamic properties of cells and active biomaterials, it is essential to consider ‘time’ as the 4th dimension in soft tissue design. Following this 4D bioprinting approach, we aimed to develop a novel model that could replicate fibroblast dynamic remodeling in vitro. For this purpose, (myo)fibroblasts were patterned on collagen gels with laser-assisted bioprinting (LAB) to study the generated matrix deformations and reorganizations. First, distinct populations, mainly composed of fibroblasts or myofibroblasts, were established in vitro to account for the variety of fibroblastic remodeling properties. Then, LAB was used to organize both populations on collagen gels in even isotropic patterns with high resolution, high density and high viability. With maturation, bioprinted patterns of fibroblasts and myofibroblasts reorganized into dispersed or aggregated cells, respectively. Stress-release contraction assays revealed that these phenotype-specific pattern maturations were associated with distinct lattice tension states. The two populations were then patterned in anisotropic rows in order to direct the cell-generated deformations and to orient global matrix remodeling. Only maturation of anisotropic fibroblast patterns, but not myofibroblasts, resulted in collagen anisotropic reorganizations both at tissue-scale, with lattice contraction, and at microscale, with embedded microbead displacements. Following a 4D bioprinting approach, LAB patterning enabled to elicit and orient the dynamic matrix remodeling mechanisms of distinct fibroblastic populations and organizations on collagen. For future studies, this method provides a new versatile tool to investigate in vitro dermal organizations and properties, processes of remodeling in healing, and new treatment opportunities.
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Bindea, M., Claudia Maria Chezan, and A. Puskas. "Numerical Analysis Of Flat Slabs With Spherical Voids Subjected To Shear Force." Journal of Applied Engineering Sciences 5, no. 1 (May 1, 2015): 7–13. http://dx.doi.org/10.1515/jaes-2015-0001.
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Abstract Full flat slabs can be enhanced by using spherical voids to replace the unemployed concrete from the core part of the slab. Therefore we get low self-weighted slabs that can reach a high range of spans, a low material consumption compared to classical solutions used so far. On the other hand, the upsides of these slabs pale against the insecurity in design stage about their punching and shear force behaviour. In this paper it is presented a parametric study about shear force behaviour of flat slabs with spherical voids used in standard condition service. The study was made using the Atena 3D finit element design software, starting form a numerical model gauged on experimental results on real models – scale 1:1. Based on these lab results, the model’s validation was made by overlapping the load – displacement experimental curves on the curves yielded from numerical analyses. The results indicate that under a longitudinal reinforcement rate of lower than 0.50%, flat slabs with spherical voids don’t fail to shear force and over this value the capable shear force decreases in comparison with solid slabs, as the reinforcement rate increases.
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Tummers, Lars, Bram Steijn, Barbara Nevicka, and Madelon Heerema. "The Effects of Leadership and Job Autonomy on Vitality: Survey and Experimental Evidence." Review of Public Personnel Administration 38, no. 3 (October 4, 2016): 355–77. http://dx.doi.org/10.1177/0734371x16671980.
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Vitality refers to the experience of having energy available to one’s self. Vital employees are full of positive energy when they work, and feel mentally and physically strong. Such employees often show higher job performance and lower stress than their less vital colleagues. Despite the importance of vitality, few public administration studies have studied vitality. More generally, by focusing on vitality, we aim to bring a “positive psychology” perspective into the domain of public administration. We analyze whether two important job characteristics (leader’s task communication and job autonomy) affect vitality. We use a multi-method design. A large-scale survey ( N = 1,502) shows that leader’s task communication and job autonomy are positively related to vitality. A lab experiment ( N = 102) replicated these findings, showing cause-and-effect relationships. In conclusion, public organizations can potentially increase employee vitality (a) by increased task communication from leaders and (b) by providing employees with greater job autonomy.
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Ngo, Khanh Hieu, Quoc Hung Pham, and Trung Tien Tran. "Designing a test rig for structural static-load testing of small horizontal axis wind turbine rotor blades." Science & Technology Development Journal - Engineering and Technology 3, SI3 (January 22, 2021): first. http://dx.doi.org/10.32508/stdjet.v3isi3.739.
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This paper presents a design of a test rig for structural static load testing of small horizontal wind turbine blades. It is a next step after the success of the DeVie project, a join-research project to boost the wind energy knowhow between Germany and Vietnam. According to the IEC-61400-23 standard for full scale structural testing of rotor blades, and based on existing facilities of HCMUT, especially the aerospace engineering lab. and the engineering mechanics lab., we propose a prototype of a test-rig for structural static load testing of rotor blades. A rotor blade of 4 meters in length, manufactured by China, is used in the case study of our structural static-load test-rig. This paper used the reverse engineering method to determine the blade geometry and performance, since the blade was provided and not designed from scratch. Detailed steps to determine the test load for the rig are the most important, based on the blade design and the wind condition of Vietnam, a study case was set to start the process. Since that required a lot of experience and know-how, beside the work and research from our university, other critically important information was kindly provided by the German's experts in the field. Result of the blade tip displacement are wildly used in this industry to validate the blade design. Our test rig result in 0.289 meters were compared to the reverse engineering and simulation result of 0.28 meter with QBlade/FAST in the same blade loading shown well similarity, this result validated our work process. Future revision of the test rig is promised to provide more function such as fatigue test mode, higher load capacity, faster testing time as well as more accurate result, aiding the domestic market of composite wind turbine blade manufacturing which is still in its infancy.
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Kannan, Pravin, Priyabrata Pal, and Fawzi Banat. "Design of adsorption column for reclamation of methyldiethanolamine using homogeneous surface diffusion model." Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 75 (2020): 82. http://dx.doi.org/10.2516/ogst/2020073.
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A predictive simulation model was applied to design a fixed-bed adsorber for studying the removal of Total Organic Acid (TOA) anions from lean Methyldiethanolamine (MDEA) solution using Calcium Alginate Bentonite (CAB) clay hybrid composite adsorbent. Unlike other conventional techniques typically used for packed bed design, the predictive Homogeneous Surface Diffusion Model (HSDM) does not require any test column breakthrough curves a priori. Mass transfer coefficients and isotherm model parameters are provided as input data to HSDM for simulating column breakthrough curves. Various isotherm models were fitted to batch equilibrium data for TOA adsorption on CAB composite adsorbent. Based on Akaike Information Criterion (AIC), Freundlich isotherm was selected and the model parameters were obtained by non-linear regression. Film transfer coefficients and surface diffusivities were determined using appropriate empirical correlations available in the literature. HSDM predictions were first validated using lab-scale column adsorption data generated at lower residence times. The effects of dimensionless numbers (Biot and Stanton) on breakthrough times were investigated using the dimensionless HSDM system and a suitable scale-up regime (Bi& ~& 1 and St& >& 10) was established wherein the sensitivity of mass transfer parameters would be minimal. Using similitude rules on key design parameters, a pilot-scale adsorption column was designed and breakthrough curves were generated using the validated HSDM. The appropriateness of the design technique was verified by comparing the estimated breakthrough data and column design parameters with conventional scale-up and kinetic approaches.
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Tahmasebinia, Faham, Marjo Niemelä, Sanee Ebrahimzadeh Sepasgozar, Tin Lai, Winson Su, Kakarla Reddy, Sara Shirowzhan, Samad Sepasgozar, and Fernando Marroquin. "Three-Dimensional Printing Using Recycled High-Density Polyethylene: Technological Challenges and Future Directions for Construction." Buildings 8, no. 11 (November 21, 2018): 165. http://dx.doi.org/10.3390/buildings8110165.
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Three-dimensional (3D) printing technologies are transforming the design and manufacture of components and products across many disciplines, but their application in the construction industry is still limited. Material deposition processes can achieve infinite geometries. They have advanced from rapid prototyping and model-scale markets to applications in the fabrication of functional products, large objects, and the construction of full-scale buildings. Many international projects have been realised in recent years, and the construction industry is beginning to make use of such dynamic technologies. Advantages of integrating 3D printing with house construction are significant. They include the capacity for mass customisation of designs and parameters to meet functional and aesthetic purposes, the reduction in construction waste from highly precise placement of materials, and the use of recycled waste products in layer deposition materials. With the ultimate goal of improving construction efficiency and decreasing building costs, the researchers applied Strand 7 Finite Element Analysis software to a numerical model designed for 3D printing a cement mix that incorporates the recycled waste product high-density polyethylene (HDPE). The result: construction of an arched, truss-like roof was found to be structurally feasible in the absence of steel reinforcements, and lab-sized prototypes were manufactured according to the numerical model with 3D printing technology. 3D printing technologies can now be customised to building construction. This paper discusses the applications, advantages, limitations, and future directions of this innovative and viable solution to affordable housing construction.
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Yang, Li. "Dynamic Compression Model Incorporating Elastic Nonlinearity of Paperboard." Journal of Packaging Technology and Research 5, no. 2 (March 24, 2021): 79–87. http://dx.doi.org/10.1007/s41783-021-00112-5.
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AbstractSpring of constant elasticity is a concept from theories of extension while elastic nonlinearity in compressive deformation is a general phenomenon for polymeric materials involved in offset or flexographic printing, paper board, polymer plate, and cushioning tape. This phenomenon needs therefore to be coped with by the model of printing dynamics. We hereby present an extended approach based on the Maxwell material model. In the extended approach, a compression process is subdivided into (or approximated by) sequential subprocesses. The elastic modulus may vary from one subsection to another but remains constant in each of the subprocesses. With the extended approach dynamic behaviours (compression/recovering) of paperboard can be reproduced and predicted. As a concrete example, dynamic behaviours of paper board in the print nip were simulated with satisfactory outcome. The simulation also revealed that viscoelasticity of the board is the origin of mechanical hysteresis of the stress–strain curve. Due to viscoelasticity and nonlinearity of the materials careful design is essential to simulate full-scale printing with a lab press.
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Mok, Ka Yan, Geoffrey Qiping Shen, and Rebecca Yang. "Stakeholder complexity in large scale green building projects." Engineering, Construction and Architectural Management 25, no. 11 (December 3, 2018): 1454–74. http://dx.doi.org/10.1108/ecam-09-2016-0205.
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Purpose In response to the world’s rising awareness on sustainability, industry players and policymakers are devoting great efforts to bolster green building developments. Every green building project (GBP) involves numerous stakeholders and potentially incompatible concerns. Despite the associated environmental, economic and social benefits, GBP developments have often confronted managerial barriers which are actually emerged from stakeholders – the actual key determinants of a project. Holistically analyzing the complexity of stakeholders in GBPs is, therefore, crucial to improving GBP management and achieving greater sustainability for all involved. The purpose of this paper is to analyze stakeholder complexity in large GBPs using a holistic framework which integrates both empirical and rationalistic analytical perspectives. Design/methodology/approach The complexity of stakeholders in GBPs can be considered from three aspects – identifying stakeholders, assessing stakeholder interactions and analyzing stakeholder concerns. The proposed stakeholder analysis framework uses both empirical methods (e.g. interviews and surveys) and rationalistic methods (e.g. chain referral sampling and social network analysis) to analyze GBP stakeholder complexity. Case study of a lab-enabled commercial GBP in Hong Kong was undertaken to illustrate the framework. Findings The framework enables a holistic, objective and effective stakeholder analysis; leading GBP leaders toward a complete understanding of project stakeholder complexity. The case study findings bring managerial insights to GBP leaders on the general SNA-related stakeholder dynamics and the important stakeholder concerns, of large Hong Kong GBPs. The findings diagnose general connectivity structures of GBP stakeholders, identify influential and peripheral actors in GBP information exchange, and suggest clues to improve their dynamics. In addition, ten key stakeholder concerns were identified, including comprehensive governmental standards and procedures, clear sustainability goals at the outset, effective stakeholder engagement, adequate design flexibility, and a “can-do” attitude of contractors and consultants – which are all vital for successful GBP development. The underlying reasons of these concerns and recommendations to addressing them were also discussed. Originality/value Many existing GBP stakeholder studies appear to use a single analytical perspective to assess project stakeholder complexity, but this may not gain a full understanding. The holistic stakeholder analysis framework used herein combines empiricism and rationalism. It helps to bring GBP leaders and implementers toward a more informed project decision making, a more thorough understanding of stakeholder complexity, as well as a more effective engagement of stakeholders.
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Habets, L. H. A., M. H. Tielbaard, A. M. D. Ferguson, C. F. Prong, and A. J. Chmelauskas. "On Site High Rate UASB Anaerobic Demonstration Plant Treatment of NSSC Wastewater." Water Science and Technology 20, no. 1 (January 1, 1988): 87–97. http://dx.doi.org/10.2166/wst.1988.0012.
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Results of a 19 m3 demonstration plant studies are summarized. The plant is located at Sturgeon Falls at a NSSC mill and hardboard plant owned by MacMillan Bloedel. The mill discharges 6300 m3/day of waste effluent containing 50 tonnes of BOD and 127 tonnes of COD. Lab scale testing (1983) and an 18 month 1.4 m3 reactor volume pilot plant study (1985) were completed confirming treatability of the wastewater and suitability of the Upflow Anaerobic Sludge Blanket (UASB) technology among others to successfully treat the mill wastewater. Discharged effluent contains spent sulphite liquor and primary clarifier effluent. As required, the 1.4 m3 Biopaq System successfully achieved BOD reductions in excess of 75 percent at loadings greater than 10 kg COD/m3.d. As a consequence of this and because of economic considerations, the Biopaq System of Paques-Lavalin was selected for on site demonstration during a 12 months period. This period started in spring 1986. Erection of a full-scale plant is planned to take place in 1988. The purpose of the on site demonstration study is to confirm wastewater treatability, optimize design loading rates and confirm granular sludge growth. To achieve the objectives and simulate full-scale operating conditions the MacMillan Bloedel pilot plant has been automated and is controlled via a microprocessor incorporating a customized software program. Start-up performance results and operation at incremental loadings under steady state conditions are presented together with the experience gained during extreme variations in mill effluent quality and flow. Preliminary study results from the first 10 months disclose that a BOD removal efficiency of 80 percent or better is achieved at weekly average loadings of 15 kg COD/m3.d, and the process offers strong resilience to daily swings in wastewater quality. The results also show a net accumulation of granular sludge. The practical application of this technology from a mill operating perspective is discussed, and the layout for a full-scale installation with projected capital and operating costs is provided. Most of the contents of this paper was presented at the Tappi 1987 Environmental Conference (Prong etal, 1987). This paper presents the latest results.
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Kalman, Viktor, Johannes Voigt, Christian Jordan, and Michael Harasek. "Hydrogen Purification by Pressure Swing Adsorption: High-Pressure PSA Performance in Recovery from Seasonal Storage." Sustainability 14, no. 21 (October 28, 2022): 14037. http://dx.doi.org/10.3390/su142114037.
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Hydrogen storage in a depleted gas field is a promising solution to the seasonal storage of renewable energy, a key question in Europe’s green transition. The gas composition and pressure in the month-long storage and recovery phase can vary substantially; meanwhile, the recovered H2 has to be pure, especially for fuel cell applications. Pressure swing adsorption can be used for the purification of the recovered gas. A lab-scale, four-bed PSA unit was built to investigate its applicability by separating different H2-CH4 mixtures. The feed parameters in the experiments are based on a depleted gas reservoir with a pressure range of 25–60 bar and methane contamination between 0 and 35%. The change in the feed properties is modeled by four distinct stages and the twelve-step cycle is tailored to each stage. The high pressure did not have any irreversible effects on the process. A hydrogen purity of 99.95% was achieved in all stages with the average hydrogen recovery ranging from 60 to 80%. The experiments revealed the challenges of a cycle design when the feed parameters are not constant, but an adequate separation performance was shown, which supports the applicability of the PSA in seasonal storage and confirms the need for further investigation with multicomponent contaminants and large-scale projects.
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Abbate, E., G. Sammartano, and A. Spanò. "PROSPECTIVE UPON MULTI-SOURCE URBAN SCALE DATA FOR 3D DOCUMENTATION AND MONITORING OF URBAN LEGACIES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W11 (May 4, 2019): 11–19. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w11-11-2019.
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<p><strong>Abstract.</strong> The investigation on the built urban heritage and its current transformations can progressively benefit from the use of geospatial data related to urban environment. This is even more interesting when urban design studies of historical and stratified cities meet the contribution of 4D geospatial data within the urban morphology researches, aiming at quickly and accurately identifying and then measuring with a spatial relationship, both localized transformation (volumes demolitions, addition, etc…) and wide-scale substantial modification resulting from urban zones of diversification spaces that incorporates urban legacies. In this domain, the comparison and analysis of multi-source and multi-scale information belonging to Spatial Data Infrastructures (SDI) organized by Municipality and Region Administration (mainly, orthoimages and DSM and digital mapping) are a crucial support for multi-temporal spatial analysis, especially if compared with new DSMs related to past urban situations. The latter can be generated by new solution of digital image-matching techniques applicable to the available historical aerial images. The goal is to investigate the amount of available data and their effectiveness, to later test different experimental tools and methods for quick detection, localization and quantification of morphological macro-transformation at urban scale. At the same time, it has been examined the opportunity to made available, with up-and-coming Mobile Mapping Systems (MMS) based on image- and range-based techniques, a rapid and effective approach of data gathering, updating and sharing at validated urban scales. The presented research, carried out in the framework of the FULL@Polito research lab, applies to urban legacies and their regeneration, and is conducted on a key redevelopment area in northern Torino, the Parco Dora, that was occupied by steel industries actively working up to 1992. The long-standing steel structures of the Ferriere FIAT lot have been refurbished and incorporated in the new urban park, generating a contemporary space with a new evolving urban fabric, and being integrated in the new updated geo-spatial databases as well.</p>
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Lai, A., Y. C. Lin, S. S. Wei, T. H. Chou, J. W. Lin, J. S. Wu, and Y. S. Chen. "Numerical Investigation of a N2O/HTPB Hybrid Rocket Motor with a Dual-Vortical-Flow (DVF) Design." Journal of Mechanics 33, no. 6 (January 24, 2017): 853–62. http://dx.doi.org/10.1017/jmech.2017.3.
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AbstractA compact hybrid rocket motor design that incorporates a dual-vortical-flow (DVF) concept is proposed. The oxidizer (nitrous oxide, N2O) is injected circumferentially into various sections of the rocket motor, which are sectored by several solid fuel “rings” (made of hydroxyl-terminated polybutadiene, HTPB) that are installed along the central axis of the motor. The proposed configuration not only increases the residence time of the oxidizer flow, it also implies an inherent “roll control” capability of the motor. Based on a DVF motor geometry with a designed thrust level of 11.6 kN, the characteristics of the turbulent reacting flow within the motor and its rocket performance were analyzed with a comprehensive numerical model that implements both real-fluid properties and finite-rate chemistry. Data indicate that the vacuum specific impulse (Isp) of the DVF motor could reach 278 s. The result from a preliminary ground test of a lab-scale DVF hybrid rocket motor (with a designed thrust level of 3,000 N) also shows promising performance. The proposed DVF concept is expected to partly resolve the issue of scalability, which remains challenging for hybrid rocket motors development.
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Santos, Athila, Na Liu, and Muhyiddine Jradi. "Design, Development and Implementation of a Novel Parallel Automated Step Response Testing Tool for Building Automation Systems." Buildings 12, no. 9 (September 17, 2022): 1479. http://dx.doi.org/10.3390/buildings12091479.
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The digital transformation has paved the path for new services and efficient management across the value chain of the whole energy sector. For applications behind the meter, buildings stand out as a major contributor to energy consumption and corresponding emissions. Therefore, Building Automation Control Systems (BACS) have been proposed in order to mitigate building performance issues. Finding optimal and automated methods to handle different control points of BACS is very important. In the initial design and commissioning phases, HVAC systems need to be tested exhaustively to guarantee proper function and expected operation compliance. However, the availability of automated step response test tools applied in the building sector is still scarce, forcing engineers around the globe to manually test different scenarios over the same buildings multiple times. This is a tedious and error-prone approach that lacks precision and good resource allocation. Therefore, we propose AUSTRET: a parallel automated multiple processing software for step response testing in buildings. The tool aims to automate the laborious step response tests of BACS cost-effectively. The input parameters can be provided for several control zones and on different control systems. The multi-processing capability allows the step response execution to run in parallel saving time and resources from the operators. The implementation of AUSTRET is first tested in a living lab environment in a university office building and then demonstrated on full-scale in a commercial building setting. The results show how the parallel processing capability of AUSTRET enhances the productivity and efficiency of step response tests in a building and how the different configuration parameters can affect the overall performance of the tests. The preliminary results indicate how automated tools, such as AUSTRET, can improve the automation and effectiveness of step response tests in the design phase or during retro-commissioning building processes.
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Costa de Oliveira, Maida Aysla, Alessandra D’Epifanio, Hitoshi Ohnuki, and Barbara Mecheri. "Platinum Group Metal-Free Catalysts for Oxygen Reduction Reaction: Applications in Microbial Fuel Cells." Catalysts 10, no. 5 (April 26, 2020): 475. http://dx.doi.org/10.3390/catal10050475.
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Scientific and technological innovation is increasingly playing a role for promoting the transition towards a circular economy and sustainable development. Thanks to its dual function of harvesting energy from waste and cleaning up waste from organic pollutants, microbial fuel cells (MFCs) provide a revolutionary answer to the global environmental challenges. Yet, one key factor that limits the implementation of larger scale MFCs is the high cost and low durability of current electrode materials, owing to the use of platinum at the cathode side. To address this issue, the scientific community has devoted its research efforts for identifying innovative and low cost materials and components to assemble lab-scale MFC prototypes, fed with wastewaters of different nature. This review work summarizes the state-of the-art of developing platinum group metal-free (PGM-free) catalysts for applications at the cathode side of MFCs. We address how different catalyst families boost oxygen reduction reaction (ORR) in neutral pH, as result of an interplay between surface chemistry and morphology on the efficiency of ORR active sites. We particularly review the properties, performance, and applicability of metal-free carbon-based materials, molecular catalysts based on metal macrocycles supported on carbon nanostructures, M-N-C catalysts activated via pyrolysis, metal oxide-based catalysts, and enzyme catalysts. We finally discuss recent progress on MFC cathode design, providing a guidance for improving cathode activity and stability under MFC operating conditions.
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Boz, Buket, Miljana Vuksanovic, Lukas Neidhart, Micheal Höchtl, Katja Fröhlich, and Marcus Jahn. "Aqueous Manufacturing of Ni-Rich Cathodes Using Polyacrylic Acid As Binder for Lithium-Ion Batteries." ECS Meeting Abstracts MA2022-02, no. 7 (October 9, 2022): 2542. http://dx.doi.org/10.1149/ma2022-0272542mtgabs.
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In the field of secondary batteries, the lithium-ion battery (LIB) is one of the most promising candidates for future electric vehicle (EV) applications, due to its high specific energy and good specific power [1]. However, to meet the demands in large scale storage, not only higher energy and power density and lower cost are needed, but environmentally friendly processing of LiBs is getting more in the focus of research. To meet the desirable requirements, one necessity is to tune the cathode in terms of sustainable production and materials. Ni-rich layered LiNi x Mn y Co1−x−y O2 (NMCs, x ≥ 0.8) cathodes are poised to be the dominating cathode materials for lithium-ion batteries for the foreseeable future due to its high energy density [2]. The state-of-the-art NMC based cathode production in both industrial and lab scale is with polyvinylidene fluoride (PVDF) in organic solvent N-methyl-2-pyrrolidone (NMP). NMP is a toxic, expensive, and highly flammable organic solvent [3]. Replacing NMP with water in the production of LiB cathodes is critical in terms of process cost savings and environmental concerns. Aqueous processes of NMC based cathodes are highly favorable as well as challenging due to the high reactivity of NMC particles. During the slurry preparation, the surface of Ni-rich particles undergoes Li leaching via exchange between H+ from water and Li+ from the active material which leads to increase in pH of the slurry. Li leaching leads to capacity fade and reduces the specific capacity of the cathode. The high pH of the slurry causes corrosion on the aluminum current collector. Surface treatment of NMC particles is a way to prevent Li leaching as well as using carbon coated Al current collector to resist the corrosion, but in terms of production cost these methods are not favorable. In this study, our fundamental aim is to demonstrate the manufacturing of large scale water based NMC811-PAA cathodes. We therefore employ a well-known binder material, polyacrylic acid (PAA), which is water soluble and an anionic polymer. During the mixing processes of the slurry, H+ from PAA can drive Li+ leaching, the leached Li+ reacts with carboxylic groups of PAA and binds to the PAA backbone. Thus, the reaction of H+ and OH- neutralizes the pH of the slurry. Bonded Li+ on PAA creates an active binder in which these Li ions can participate as an additional Li source to aid to prevent capacity decrease. This method has been successfully implemented in the lab scale [4]. Our main target is to investigate the slurry behavior and scalability of the cathodes with a PAA binder. Herein, we report high solid content of slurry behavior of NMC with PAA and the comparison to the conventionally produced slurry for the first time. Also, we show how the slurry behavior is affected by the mixing techniques from lab scale to pilot scale, which is an important parameter for later transfer to industrial production. The electrodes and successfully formed LiPAA as binder are shown by Fourier transformed infrared (FTIR) and Raman spectroscopy. The electrochemical tests are performed both in half and full cell configuration for NMC811-PAA and NMC811-PVDF cathodes. References [1] Tao, Yanqiu, et al. "Second life and recycling: Energy and environmental sustainability perspectives for high-performance lithium-ion batteries." Science advances 7.45 (2021): eabi7633. https://doi.org10.1126/sciadv.abi7633. [2] Lu, Yanying, et al. "Single‐crystal LiNixMnyCo1− x− yO2 cathodes for extreme fast charging." Small 18.12 (2022): 2105833. https://doi.org/10.1002/smll.202105833. [3] Zou, Feng, and Arumugam Manthiram. "A review of the design of advanced binders for high‐performance batteries." Advanced Energy Materials 10.45 (2020): 2002508. https://doi.org/10.1002/aenm.202002508. [4] Hawley, W. Blake, Harry M. Meyer III, and Jianlin Li. "Enabling aqueous processing for LiNi0. 80Co0. 15Al0. 05O2 (NCA)-based lithium-ion battery cathodes using polyacrylic acid." Electrochimica Acta 380 (2021): 138203. https://doi.org/10.1016/j.electacta.2021.138203.
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Macauley, Natalia, Sichen Zhong, Yachao Zeng, Bingzhang Zhang, Gang Wu, and Hui Xu. "Fabrication and Scale-up of Highly Durable Heavy Duty Fuel Cell MEAs." ECS Meeting Abstracts MA2022-01, no. 35 (July 7, 2022): 1426. http://dx.doi.org/10.1149/ma2022-01351426mtgabs.
Повний текст джерелаАнотація:
Medium and heavy-duty PEM fuel cells operate under much harsher conditions than light duty fuel cells and are expected to last 25,000 hours in the field. These systems must therefore operate successfully in the presence of impurities, starting and stopping, freezing and thawing, humidity and load cycling. Therefore, materials, components, and interfaces used in such systems need to be highly resistant to severe mechanical and chemical stress. Novel, highly active stable Pt and ordered PtCo intermetallic nanoparticles with well-controlled particle size and composition have been synthesized on a highly efficient PGM-free single metal active site rich carbon, to maximize their synergistic effects for enhanced performance and durability. These catalysts were integrated with a variety of ionomers (Aquivion, Nafion, HOPI and high O2 permeability ionomer (HOPI)) to further improve fuel cell performance and to achieve >600 mA/mgPt at 0.9 VIR-free with a mass activity loss less than 30% after 150k square wave accelerated durability cycles; and > 600 mA/cm2 (~65% efficiency) at 0.8 V, with a performance loss < 40 mV after 150K cycles (0.6 to 0.95 V). In a PEM fuel cell, the catalyst ink formulation and mixing processes control catalyst layer coating quality, electrode morphology, and the resulting fuel cell performance and durability. Catalyst ink properties are a result of complex solvent-catalyst-ionomer interactions that depend on the mixing method employed. Here, we will compare the performance and durability of electrodes made from bath sonicated inks for ultrasonic spray coating vs. ball milled inks for Meyer rod coating. Ink rheology and catalyst particle size will be used to correlate ink properties to electrode morphology and structure and ensure consistency from batch to batch, and from small lab scale to subsequent scale-up. We will evaluate and discuss the challenges that arise when transitioning from spray coating catalyst ink on a small scale, directly on a membrane, to coating more viscous inks on gas diffusion layers (GDLs), and finally developing a roll-to-roll (R2R) fabrication process. The MEA performance and durability of the novel catalyst will be evaluated under heavy duty operating conditions. Finally, the electrode performance and durability of R2R fabricated GDEs will be tested, and compared to small scale GDEs made at Giner. This work provides a comprehensive understanding of interactions between Pt, PtCo, carbon, ionomer, membrane, and GDLs and their impact on electrode structure, fuel cell performance and durability, as well as considerations for scale up to a R2R fabrication process. The attained information will be used to improve fuel cell electrode design, fabrication and scale-up. Acknowledgement: The project is financially supported by the Department of Energy’s Fuel Cell Technology Office under the Grant DE-FOA-0002360.
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Kerdsuwan, Somrat. "Innovative Design and Manufacturing Technology of High Temperature Air Combustion (HTAC) Municipal Solid Waste Incinerator." Applied Mechanics and Materials 789-790 (September 2015): 377–81. http://dx.doi.org/10.4028/www.scientific.net/amm.789-790.377.
Повний текст джерелаАнотація:
Incineration is a Thermal Treatment Technology (3Ts) that could be expressed as the way to get rid of waste effectively with the reduction of its mass and volume. However, to control the combustion process efficiently, especially combustion temperature, with low energy content in Municipal Solid Waste (MSW), an additional fuel is needed and leads to increase of operating cost compared with other disposal option. High Temperature Air Combustion (HTAC) has been successfully demonstrated in a lab-scale incinerator for energy saving and pollutant reduction, especially NOx. This article has the objective to design and manufacture the prototype scale High Temperature Air Incinerator with a capacity to treat MSW of 12 Ton per day. The system consists of an automatic feeding machine to feed the waste into the primary combustion chamber (PCC) where the combustion takes place. The push ram is used to push the burning waste and fall down to the lower hearth. Primary combustion air is supplied into PCC at the amount lower than the stoichiometric requirement to produce the combustible gas which is flown into the Secondary Combustion Chamber (SCC) located above PCC. Secondary combustion air is injected to react with combustible gas to convert to the product of complete combustion. A part of hot flue gas which is flew out from SCC is reverted and mixed with fresh air, in order to reduce oxygen concentration, before passing through the heat exchanger tube bundle which is placed inside SCC in order to exchange heat with hot flue gas. To manufacture the designed incinerator, the detail of materials used as well as the frabication method is explained. It has been shown that HTAC can be applied for thermal destruction of waste successfully, in term of energy saving and pollutant free. Benefits of this research work will promote the using of thermal treatment technology of dispose of MSW with lower operating cost and lower pollutants.
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Szücs, Botond, and Pál Szentannai. "Experimental Investigation on Mixing and Segregation Behavior of Oxygen Carrier and Biomass Particle in Fluidized Bed." Periodica Polytechnica Mechanical Engineering 63, no. 3 (May 20, 2019): 188–94. http://dx.doi.org/10.3311/ppme.13764.
Повний текст джерелаАнотація:
In this work, lab-scale cold fluidization equipment is designed and constructed to investigate the mixing and segregating phenomena of binary fluidized beds. The focus of the investigation is carbon reduction with the fluidized bed technology-based Chemical Looping Combustion (CLC). Nowadays, aspiration to carbon reduction focuses on the solid fuels. Therefore, it is of great importance to integrate the benefits of CLC technology with the use of solid fuels. The measurements of fuel particles in the fluidized bed are extended from the homogeneous and spherical shape to the inhomogeneous, non-spherical shape. During the tests, an iron-based oxygen carrier (OC) for chemical looping combustors is examined with different particle sizes. In addition, the tests included the examination of three different fuel samples (crushed coal, agricultural pellet, and Solid Recovered Fuel (SRF)), which can be utilized in chemical looping combustion with In-situ gasification. The experiments are carried out using the bed-frozen method. With this method, the vertical concentration of active particles could be measured. The results show that the particle size of the oxygen carrier does fundamentally influence its vertical placement, and the non-spherical character of most alternative fuels must also be considered for optimal reactor design.
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Solomakha, Kseniia. "PUBLIC ATTITUDES TO VISITING SWIMMING POOLS AND WATER PARKS (according to the survey and lab results)." Ukrainian Scientific Medical Youth Journal 125, no. 3 (September 30, 2021): 64–74. http://dx.doi.org/10.32345/usmyj.3(125).2021.64-74.
Повний текст джерелаАнотація:
Recreational activities by the water are quite popular today. Swimming is one of the most popular ways of spending free time and sports activities, also swimming has few contraindications and, in general, is usually a good idea at any age. In our country we have a wide network of various water complexes from small spas, baths, swimming pools to large-scale water parks. At the same time, we can notice that visiting swimming pools, water parks, spa centers and other water complexes is associated with an increased risk of infectious and parasitic diseases, injuries, manifestations of allergic reactions in visitors, therefore, constant monitoring of the operation of such complexes is mandatory, as well as control at the design phase, because it`s easier to prevent some moments than to correct them in the future. Water treatment methods occupy an important place in the system of monitoring the parameters of the internal environment of the water complex and the quality of water in the pools, and these methods included filtration, disinfection, and water circulation conditions. The operation of the pool is inevitably associated with water pollution: it can be with pathogenic microorganisms, organic substances and the remains of cosmetics which enter the water with the swimmers. In this case, an insufficient level of culture of visitors, especially young children, who, due to their age, cannot control their physiological needs, also play a negative role. An important point is also the long-term use of water and not frequent sanitization of the pools (with a full drain of water). The unsatisfactory sanitary state of these complexes is also facilitated by the fact that the medical examination of visitors is rather formal, and in spa centers and water parks, which are most often visited by completely different people every day, they are not needed at all, as well as a certificate of good health; that’s why the implementation of sanitary and hygienic standards and modes of operation of pools and other water complexes is mandatory, in practice, unfortunately, in our country it completely depends on the awareness of business owners.
However, the issue of safety while visiting such water complexes is important. The main purpose of our research was to analyze how visitors subjectively assess the safety of visiting water complexes, and to identify the main complaints that arise in those complexes where the main method of water disinfection is chlorination. Materials and methods: we did a cross-sectional survey among visitors of swimming pools and water parks during the period from August 2019 to December 2020 as well as the water samples were collected and analyzed. The practical significance of the obtained results was to identify the main trends, problems, and critical moments from the subjective point of view of the visitors and to be able to assess the importance of hygienic education while visiting water complexes. Conclusions: in general, we note the lack of knowledge and awareness of hygiene issues before and after visiting the swimming pool (water park), which should be noted by professionals responsible for the health of visitors of different water complexes.
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Islam, A. K. M. Khabirul, Patrick S. M. Dunlop, Neil J. Hewitt, Rose Lenihan, and Caterina Brandoni. "Bio-Hydrogen Production from Wastewater: A Comparative Study of Low Energy Intensive Production Processes." Clean Technologies 3, no. 1 (February 18, 2021): 156–82. http://dx.doi.org/10.3390/cleantechnol3010010.
Повний текст джерелаАнотація:
Billions of litres of wastewater are produced daily from domestic and industrial areas, and whilst wastewater is often perceived as a problem, it has the potential to be viewed as a rich source for resources and energy. Wastewater contains between four and five times more energy than is required to treat it, and is a potential source of bio-hydrogen—a clean energy vector, a feedstock chemical and a fuel, widely recognised to have a role in the decarbonisation of the future energy system. This paper investigates sustainable, low-energy intensive routes for hydrogen production from wastewater, critically analysing five technologies, namely photo-fermentation, dark fermentation, photocatalysis, microbial photo electrochemical processes and microbial electrolysis cells (MECs). The paper compares key parameters influencing H2 production yield, such as pH, temperature and reactor design, summarises the state of the art in each area, and highlights the scale-up technical challenges. In addition to H2 production, these processes can be used for partial wastewater remediation, providing at least 45% reduction in chemical oxygen demand (COD), and are suitable for integration into existing wastewater treatment plants. Key advancements in lab-based research are included, highlighting the potential for each technology to contribute to the development of clean energy. Whilst there have been efforts to scale dark fermentation, electro and photo chemical technologies are still at the early stages of development (Technology Readiness Levels below 4); therefore, pilot plants and demonstrators sited at wastewater treatment facilities are needed to assess commercial viability. As such, a multidisciplinary approach is needed to overcome the current barriers to implementation, integrating expertise in engineering, chemistry and microbiology with the commercial experience of both water and energy sectors. The review concludes by highlighting MECs as a promising technology, due to excellent system modularity, good hydrogen yield (3.6–7.9 L/L/d from synthetic wastewater) and the potential to remove up to 80% COD from influent streams.
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Abdulmajid, M. N., N. P. Herodotos, and E. A. Gordon. "Experimental Aircraft Fuel Tank Vapour/Air Explosions Using Jet A and Jet A / Gasoline Blend Fuels." African Journal of Health, Safety and Environment 2, no. 2 (August 25, 2021): 55–71. http://dx.doi.org/10.52417/ajhse.v2i2.141.
Повний текст джерелаАнотація:
The potential of a fuel tank explosion is a well-known hazard in the aircraft industry. In this study, an investigation of a lab scale aircraft fuel tank in a flight situation at varying initial pressures of 400 - 1,000 mbar (equivalent to altitudes of 0 - 22,300 ft) and at variable temperatures was conducted in a 100-litre cylindrical test rig. A standard Jet A fuel and with a type Jet B fuel (which in this case was a Jet A with 10% of gasoline by mass) were used. Their flashpoints were measured to be 45oC (Jet A) and 20 oC (Jet B). In the simulated fuel tank explosions ignition occurred when the fuel liquid temperature was much higher than the flash point - 71 – 107 oC depending on initial pressure (altitude) for Jet A and 57 – 95 oC for the more volatile Jet B. The resulting maximum explosion overpressures were high, ranging from 0.7 to 5.8 bar, much higher than typical design strengths of aircraft fuel tanks, and much stronger than anticipated overpressures on the basis of ignition at or close to the lower flammability limit (LFL). It is postulated that these pressures are due to the distance between the liquid fuel surface and the ignition point and the formation of a vapour cloud with decreasing concentration with height above the fuel (being at LFL at the ignition point) and hence an overall concentration much higher than LFL. This demonstrated that severe explosions are fuel tanks are likely and the assumption that the explosion will be a near lean limit event is not safe. The work also provided explosion severity index data which can be used in design of suppression and venting systems for the mitigation of aircraft fuel tank explosions and provided other quantitative data to help manage this explosion risk appropriately.
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Orfino, Francesco P., Yadvinder Singh, Dilip Ramani, Robin T. White, Sebastian Eberhardt, Yixuan Chen, Jonas Stoll, Monica Dutta, and Erik Kjeang. "Polymer Electrolyte Fuel Cell Degradation Investigations Using X-Ray Computed Tomography." ECS Meeting Abstracts MA2022-01, no. 41 (July 7, 2022): 2508. http://dx.doi.org/10.1149/ma2022-01412508mtgabs.
Повний текст джерелаАнотація:
On-going research is aimed at commercializing low temperature fuel cell technology systems as zero emission alternatives for automotive applications in order to reduce greenhouse gas emissions and air pollution. These systems use polymer electrolyte fuel cells (PEFCs) to generate electricity via an electrochemical process using hydrogen and ambient air (oxygen) to produce water. Advantages of PEFCs include quick start-up time, low operating temperature, low weight, high efficiency, and relatively simple design. An important area of current research is the identification of factors which affect fuel cell performance degradation during operation and ultimately, its durability. A technique that has yielded new insights in the investigation and identification of failure modes in fuel cells is lab-based X-ray computed tomography (XCT), which is most advantageous due to its on-demand availability. The Fuel Cell Research Laboratory (FCReL) at Simon Fraser University currently operates Canada’s only facility for multi-length scale XCT, comprising of two state-of-the-art laboratory-based XCT scanners from Carl Zeiss X-ray Microscopy (Zeiss Xradia 520 Versa and 810 Ultra) with complementary resolution and field of view capabilities. This unique combination offers unprecedented access to investigations at multi length scales; with an ability to probe fuel cell components at the micro as well as the nano scale. Figure 1 illustrates the fuel cell holder and its orientation with respect to the X-ray beam as well as an exploded view of the miniature fuel cell design. An overview of recent fuel cell degradation investigations at FCReL using the XCT technique will be shown. The XCT based workflow facilitates determination and quantification of material structure and properties changes resulting from degradation stresses associated with operational parameters such as temperature, relative humidity, and voltage. The non-destructive nature of lab-based XCT visualization coupled with the ability to scan the same fuel cell multiple times without inducing damage [1] has enabled detailed studies of fuel cell degradation evolution in four dimensions (3D space, 1D time) [2 - 4]. The new knowledge gained from this procedure has led to root cause identification with respect to membrane and catalyst layer crack initiation and propagation [5 - 7], sealing issues [8,9], and subsequent mitigation toward enhanced fuel cell durability. Acknowledgement This research was supported by the Natural Sciences and Engineering Research Council of Canada, Canada Foundation for Innovation, British Columbia Knowledge Development Fund, Western Economic Diversification Canada, Canada Research Chairs, and Ballard Power Systems. References: [1] R.T. White, M. Najm, M. Dutta, F.P. Orfino, E. Kjeang, J. Electrochem. Soc. 163 (2016) F1206-F1208 [2] R.T. White, A. Wu, M. Najm, F.P. Orfino, M. Dutta, E. Kjeang, J. Power Sources 350 (2017) 94-102 [3] R. T. White, S. H. Eberhardt, Y. Singh, T. Haddow, M. Dutta, F. P. Orfino, E. Kjeang, Scientific Reports, (2019) 9:1843 [4] R. T. White, D. Ramani, S. H. Eberhardt, M. Najm, F. P. Orfino, M. Dutta, and E. Kjeang, J. Electrochem Soc, 166 (2019) F914-F925 [5] Y. Singh, R. T. White, M. Najm, T. Haddow, V. Pan, F. P. Orfino, M. Dutta, and E. Kjeang, J. Power Sources, 412 (2019) 224 [6] D. Ramani, Y. Singh, R. T. White, M. Wegener, F. P. Orfino, M. Dutta, and E. Kjeang, International Journal of Hydrogen Energy, 45 (2020) 10089-10103 [7] D. Ramani, Y. Singh, R. T. White, T. Haddow, M. Wegener, F. P. Orfino, L. Ghassemzadeh, M. Dutta, and E. Kjeang, Electrochimica Acta 380 (2021) 138194 [8] Y. Chen, Y. Singh, D. Ramani, F. P. Orfino, M. Dutta, and E. Kjeang, J. Power Sources, 520 (2022) 230674 [9] Y. Chen, Y. Singh, D. Ramani, F. P. Orfino, M. Dutta, and E. Kjeang, J. Power Sources, 520 (2022) 230673 [10] J. Stoll, F. P. Orfino, M. Dutta, and E. Kjeang, J. Electrochem Soc, (2021) 168 024516 Figure 1
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Fantucci, Hugo, Jaspreet S. Sidhu, and Rafael M. Santos. "Mineral Carbonation as an Educational Investigation of Green Chemical Engineering Design." Sustainability 11, no. 15 (August 1, 2019): 4156. http://dx.doi.org/10.3390/su11154156.
Повний текст джерелаАнотація:
Engaging students in the experimental design of “green” technology is a challenge in Chemical Engineering undergraduate programs. This concept paper demonstrates an educational methodology to investigate accelerated mineral carbonation, which is a promising technology related to mitigation of climate change by sequestering carbon dioxide (CO2) from industrial sources as stable solid carbonates. An experimental investigation is conceived, whereby students test the effect of two process parameters (CO2 pressure and mixing rate) on the extent of carbonation reaction. The carbonation reaction has been performed using a mineral called wollastonite (CaSiO3). The experimental study and laboratory report cover principles of reaction kinetics and mass transfer, while illustrating the steps to develop and investigate a green process technology. The results from the experimental investigation, which is carried out by multiple teams of students, are then pooled and used to guide a subsequent design project. Students would conceive a flowsheet, size equipment, and estimate the energy demand and net CO2 sequestration efficiency of a full-scale implementation of the mineral carbonation technology. This educational investigation aims to help undergraduate students to acquire deeper experiential learning and greater awareness of future green technologies by applying fundamental engineering principles into an engaging experimental and design exercise.
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Zahid, Sehar, Sadia Qasim, Muhammad Anwar, Syed Abdullah Mazhar, Shahzia Siddique, and Arshad Rafique. "Predictive Accuracy of Full Outline of Unresponsiveness Score and GCS to Predict Patient’s Poor Outcome in Pediatrics ICU." Pakistan Journal of Medical and Health Sciences 16, no. 8 (August 31, 2022): 72–73. http://dx.doi.org/10.53350/pjmhs2216872.
Повний текст джерелаАнотація:
Aim: To compare the predictive accuracy of Glasgow coma Scale (GCS) versus full outline of unresponsiveness score (FOUR score) for poor out-come prediction in children admitted in paediatric ICU. Study design: Descriptive cross-sectional study. Place and duration of study: Department of Pediatrics, Services Hospital Lahore from 29th June 2017 to 29th December 2017. Methodology: One hundred and seventy children were enrolled. Both GCS and FOUR scale scores were recorded in paediatric intensive care unit (ICU) by clinical examination within 30 minutes of arrival in ICU. Both GCS and FOUR score were calculated on each and every patient. Responses were noted by clinically examining the eye, motor, verbal and brain stem reflexes. Patients were followed upto 7 days and poor outcome was noted. Results: The frequency of pediatric mortality was 52 (30.59%). Predictive accuracy of Full Outline of Unresponsiveness Score (FOUR score) for poor outcome prediction in children admitted in paediatrics ICU showed 63.46% for sensitivity, 86.44% for specificity, 67.35% for PPV, 84.30% for NPV and 79.41% for accuracy rate, whereas predictive accuracy of GCS Score for prediction of poor outcome in children admitted in paediatrics ICU shows 55.76% for sensitivity, 83.89% for specificity, 60.42% for PPV, 81.15% for NPV and 75.29% for accuracy rate. Conclusion: The FOUR and GCS both showed good results in terms of mortality after one week of admission in pediatric ICU. Key words: Children, poor outcome, FOUR score, Glasgow coma scale, predictive accuracy
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Weinschenk, Craig, Daniel Madrzykowski, and Paul Courtney. "Impact of Flashover Fire Conditions on Exposed Energized Electrical Cords/Cables." Fire Technology 56, no. 3 (October 29, 2019): 959–91. http://dx.doi.org/10.1007/s10694-019-00915-8.
Повний текст джерелаАнотація:
Abstract There has been prior research exploring the exposure of common electrical cords and cables to fire, but that has traditionally been at the lab scale and under near steady-state exposures. The goal of these experiments was to expose six types of cords and cables in a room-scale compartment with a fuel load sufficient to drive the compartment through flashover. The basic test design was to expose the cords and cables on the floor of a compartment to a growing fire to determine the conditions under which the cord/cable would trip the circuit protection device. All of the cords were energized and installed on a non-combustible surface. The six cables and cords were protected by three different circuit protection devices which were remote from the thermal exposure. This configuration resulted in 18 exposures per experiment. The room fires experiments consisted of three replicate fires with two sofas as the main fuel source, two replicate fires with one sofa as the main fuel source and one fire with two sofas and vinyl-covered MDF paneling on three walls in the room. Each fuel package was sufficient to support flashover conditions in the room. The average peak heat release rate of the sofa fueled compartment fires with gypsum board ceiling and walls prior to suppression was 6.8 MW. The addition of vinyl covered MDF wall paneling on three of the compartment walls increased the pre-suppression peak heat release rate to 12 MW. In each experiment during post flashover exposure, the insulation on the cords and cables ignited and burned through, exposing bare wire. During this period, the circuits faulted. Assessments of both the thermal exposure and physical damage to the cords did not reveal any correlation between the thermal exposure, cord/cable damage, and trip type.
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Yu, Xueqiao, Maoxiang Lang, Yang Gao, Kai Wang, Ching-Hsia Su, Sang-Bing Tsai, Mingkun Huo, Xiao Yu, and Shiqi Li. "An Empirical Study on the Design of China High-Speed Rail Express Train Operation Plan—From a Sustainable Transport Perspective." Sustainability 10, no. 7 (July 16, 2018): 2478. http://dx.doi.org/10.3390/su10072478.
Повний текст джерелаАнотація:
The sustained and steady development of China’s economy has led to the rapid improvement of the logistics. At the same time, the rise of the e-commerce mode has given rise to a huge demand for express delivery and the express industry has entered a period of boom. Fortunately, China’s high-speed rail network has been networked, and the development of a high-speed rail express train has entered the test stage. After the high-speed rail express train is put into use, it could effectively relieve the pressure of highway transportation and significantly reduce transport pollution. To make better use of high-speed rail transport resources and give full play to its green and efficient advantages, this study established a two-stage model of a high-speed rail express train operation plan. In the first stage, a train candidate set generation model aiming for the minimum total cost of train operation was established that considered the high-speed line carrying capacity, section flow capacity, and OD requirement satisfaction constraints, which reduces the scale of train spare parts and improves the efficiency of solution. In addition, a column generation algorithm was designed to solve the model. In the second stage, an accurate flow distribution model aiming for the optimal economic efficiency was established, and then the high-speed express train operation plan was designed completely. The computational results are encouraging and demonstrate the effectiveness of the model and solution method.
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Bagemihl, Isabell, Volkert van Steijn, and J. van Ommen. "Modelling the Electrochemical Reduction of CO2 Under Gas-Liquid Channel Flow." ECS Meeting Abstracts MA2022-02, no. 49 (October 9, 2022): 1901. http://dx.doi.org/10.1149/ma2022-02491901mtgabs.
Повний текст джерелаАнотація:
Electrochemical reduction of CO2 using renewable energy sources is a promising avenue for sustainable production of bulk chemicals. The feasibility of electrochemical CO2 conversion has been demonstrated at lab scale, leading researchers to propose several reactor designs. However, CO2 electrolysis in aqueous systems is severely limited by mass transfer leading to performance parameters insufficient for industrial application. A strategy to enhance mass transfer is to actively introduce CO2 as a gas flow, while keeping diffusion paths between reactants and catalyst short, by separating the gas flow from the liquid electrolyte through a gas diffusion electrode. However, flooding, salt formation, or drying out of the gas diffusion electrode are common problems and present a major obstacle towards commercialisation. A promising reactor concept that enhances mass transfer without the complexity of a gas diffusion electrode is a structured reactor operated under gas-liquid Taylor flow: gas–liquid flow consisting of elongated bubbles in micro- or milli-channels. While this is a proven concept to enhance mass transfer for heterogeneous catalysis in flow cells, literature on this approach for electrochemical processes is scarce and the effect of process conditions on the reactor performance are poorly understood. In this work, we propose a tubular cell design, inspired from the field of fuel cells, for CO2 electrolysis with a zero-gap membrane electrode assembly. We further, develop a simple analytical model revealing how reactor performance in terms of faradaic efficiency and current density is governed by the key features of Taylor flow. These features film thickness, bubble velocity, and volume fraction of CO2 bubbles over aqueous electrolyte, for a given cathode potential. We find that the film thickness and the volume ratio of CO2/electrolyte fed to the reactor significantly affect the limiting current density and the faradaic efficiency. Additionally, we find industrially relevant performance with faradaic efficiencies (> 90 %) at current densities of up to 500 mA cm-2, when operating the reactor at elevated pressure beyond 5 bar. This demonstrates the general potential of this reactor concept to overcome mass transfer limitations in the field of electrolysis. We compare our predictions with numerical simulations, showing good agreement for a large window of operation conditions, illustrating when the simple predictive expressions for the current density and faradaic efficiency can be applied. We will discuss the importance of including interdependencies on the reactor scale to assess the economic viability of a reactor design and presents a tool to evaluate reactor design choices. We expect that the simple predictive expressions are instrumental in guiding experimental studies and reactor design choices, taking into account both technical and economic considerations.
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Sudirjo, de Jager, Buisman, and Strik. "Performance and Long Distance Data Acquisition via LoRa Technology of a Tubular Plant Microbial Fuel Cell Located in a Paddy Field in West Kalimantan, Indonesia." Sensors 19, no. 21 (October 25, 2019): 4647. http://dx.doi.org/10.3390/s19214647.
Повний текст джерелаАнотація:
A Plant Microbial Fuel Cell (Plant-MFCs) has been studied both in the lab and in a field. So far, field studies were limited to a more conventional Plant-MFC design, which submerges the anode in the soil and places the cathode above the soil surface. However, for a large scale application a tubular Plant-MFC is considered more practical since it needs no topsoil excavation. In this study, 1 m length tubular design Plant-MFC was installed in triplicate in a paddy field located in West Kalimantan, Indonesia. The Plant-MFC reactors were operated for four growing seasons. The rice paddy was grown in a standard cultivation process without any additional treatment due to the reactor instalation. An online data acquisition using LoRa technology was developed to investigate the performance of the tubular Plant-MFC over the final whole rice paddy growing season. Overall, the four crop seasons, the Plant-MFC installation did not show a complete detrimental negative effect on rice paddy growth. Based on continuous data analysis during the fourth crop season, a continuous electricity generation was achieved during a wet period in the crop season. Electricity generation dynamics were observed before, during and after the wet periods that were explained by paddy field management. A maximum daily average density from the triplicate Plant-MFCs reached 9.6 mW/m2 plant growth area. In one crop season, 9.5–15 Wh/m2 electricity can be continuously generated at an average of 0.4 ± 0.1 mW per meter tube. The Plant-MFC also shows a potential to be used as a bio sensor, e.g., rain event indicator, during a dry period between the crop seasons.
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Sol-Sánchez, M., T. Mattinzioli, J. M. Castillo-Mingorance, F. Moreno-Navarro, and M. C. Rubio-Gámez. "GRIDMAT—A Sustainable Material Combining Mat and Geogrid Concept for Ballasted Railways." Sustainability 14, no. 18 (September 7, 2022): 11186. http://dx.doi.org/10.3390/su141811186.
Повний текст джерелаАнотація:
Under ballast mats (UBM) have demonstrated their capacity to reduce section stiffness and ballast degradation. However, UBM can cause ballast destabilisation under some circumstances due to excessive vertical track deflections, requiring the installation of geogrids over the mat which increases costs and time. As alternative to this solution, this paper shows the design of GridMat: a sustainable technology for ballasted railways that combines the concepts of geogrids and under ballast mats (UBM) manufactured from recycled crumb rubber. This aims to provide damping capacity while limiting the oscillations and settlement of ballast layer. To obtain the optimal GridMat design, five different configurations varying the aperture size and void areas were assessed through laboratory box tests reproducing the track section including the GridMat. Results showed that the optimal Gridmat was of 55 mm aperture seize and 25% void area. To evaluate the sustainability of this design, the expected number of conservation and renewal operations were calculated from full-scale laboratory tests and a life-cycle assessment and life-cycle cost analysis were undertaken. GridMat showed long-term reduction in ballast degradation and track settlement, reducing need for maintenance and renewal operations in comparison with standard mats.
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Wenten, I. G., S. Steven, A. Dwiputra, Khoiruddin, and A. N. Hakim. "From lab to full-scale ultrafiltration in microalgae harvesting." Journal of Physics: Conference Series 877 (July 2017): 012002. http://dx.doi.org/10.1088/1742-6596/877/1/012002.
Повний текст джерела