SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "LAR1:uu ;hsvcat:2;mspu:(article)"

Sökning: LAR1:uu > Teknik > Tidskriftsartikel

  • Resultat 1-10 av 5544
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Zambrano, Jesús, et al. (författare)
  • Optimal steady-state design of zone volumes of bioreactors with Monod growth kinetics
  • 2015
  • Ingår i: Biochemical Engineering Journal. - : Elsevier BV. - 1369-703X .- 1873-295X. ; 100, s. 59-66
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper deals with steady-state analysis and design of bioreactors consisting of a number of completely stirred tank reactors (CSTRs) in series. The study is confined to one consumed (substrate) and one consuming constituent (biomass). The specific microbial growth rate is assumed to be described by Monod kinetics. The death of biomass is assumed to be negligible. Two optimal design problems for a large number of CSTRs in series are studied: to minimize the effluent substrate concentration for a given total volume, and to minimize the total volume for a given effluent substrate concentration. As an appealing alternative to solve these problems numerically, it is proposed to consider the asymptotic case where the number of CSTRs tends to infinity. This is shown to correspond to one CSTR in series with a plug flow reactor (PFR). A CSTR with a sufficient large volume is needed to avoid wash-out of the biomass. The main result is that both design problems for the CSTR + PFR configuration have the same solution with respect to the optimal volume of the CSTR, which is given as an explicit function of the incoming substrate concentration, the volumetric flow rate and the coefficients of the Monod growth rate function. Numerical results indicate that the plug flow approach may be used as a feasible design procedure even for a reasonably low number of CSTRs in series.
  •  
2.
  • Öhman, Sebastian, 1991-, et al. (författare)
  • Selective kinetic growth and role of local coordination in forming Al2TiO5-based coatings at lower temperatures
  • 2021
  • Ingår i: Materials Advances. - : Royal Society of Chemistry. - 2633-5409. ; 2:17, s. 5737-5751
  • Tidskriftsartikel (refereegranskat)abstract
    • Negative thermal expansion is an elusive property found among certain materials, whose potential applications have remained limited due to the many challenges faced in their synthesis. Herein, we report the successful formation of aluminium titanate-based coatings (Al2TiO5), a material renowned for its low-to-negative thermal expansion, by the co-deposition of aluminium-isopropoxide and titanium-isopropoxide in a hot-wall chemical vapour deposition instrument. While coatings grown at 450 °C were amorphous as-deposited, a short-range order into the Al2TiO5-phase was found and analysed by using Raman spectroscopy. Upon subsequent annealing at 700 °C for 3 hours, crystalline coatings were achieved without forming any binary phases. The selective synthesis of the Al2TiO5 phase is ascribed to the precursors’ inherent chemical similarities, resulting in a kinetic targeting of this phase and a short-range homogeneity, entailing its preferred crystallisation. The role of local coordination is expressed by demonstrating the formation of intergrowth phases ascribed to lower coordinating interstices in the compound. Both the formation and crystallisation temperatures reported herein, as well as the timescales needed for the synthesises, are considerably lower than any conventional adopted solid-state techniques used so far to attain the Al2TiO5 phase.
  •  
3.
  • Samuelsson, Oscar, et al. (författare)
  • Fault signatures and bias progression in dissolved oxygen sensors
  • 2018
  • Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 78:5, s. 1034-1044
  • Tidskriftsartikel (refereegranskat)abstract
    • Biofilm fouling is known to impact the data quality of sensors, but little is known about the exact effects. We studied the effects of artificial and real biofilm fouling on dissolved oxygen (DO) sensors in full-scale water resource recovery facilities, and how this can automatically be detected. Biofilm fouling resulted in different drift direction and bias magnitudes for optical (OPT) and electrochemical (MEC) DO sensors. The OPT-sensor was more affected by biofilm fouling compared to the MEC-sensor, especially during summer conditions. A bias of 1 mg/L was detected by analysing the impulse response (IR) of the automatic air cleaning system in the DO sensor. The IR is an effect of a temporal increase in DO concentration during the automatic air cleaning. The IRs received distinct pattern changes that were matched with faults including: biofilm fouling, disturbances in the air supply to the cleaning system, and damaged sensor membrane, which can be used for fault diagnosis. The results highlight the importance of a condition-based sensor maintenance schedule in contrast to fixed cleaning intervals. Further, the results stress the importance of understanding and detecting bias due to biofilm fouling, in order to maintain a robust and resource-efficient process control.
  •  
4.
  • Chen, Dongliang, et al. (författare)
  • The Scanner of Heterogeneous Traffic Flow in Smart Cities by an Updating Model of Connected and Automated Vehicles
  • 2022
  • Ingår i: IEEE transactions on intelligent transportation systems (Print). - : IEEE. - 1524-9050 .- 1558-0016. ; 23:12, s. 25361-25370
  • Tidskriftsartikel (refereegranskat)abstract
    • The problems of traditional traffic flow detection and calculation methods include limited traffic scenes, high system costs, and lower efficiency over detecting and calculating. Therefore, in this paper, we presented the updating Connected and Automated Vehicles (CAVs) model as the scanner of heterogeneous traffic flow, which uses various sensors to detect the characteristics of traffic flow in several traffic scenes on the roads. The model contains the hardware platform, software algorithm of CAV, and the analysis of traffic flow detection and simulation by Flow Project, where the driving of vehicles is mainly controlled by Reinforcement Learning (RL). Finally, the effectiveness of the proposed model and the corresponding swarm intelligence strategy is evaluated through simulation experiments. The results showed that the traffic flow scanning, tracking, and data recording performed continuously by CAVs are effective. The increase in the penetration rate of CAVs in the overall traffic flow has a significant effect on vehicle detection and identification. In addition, the vehicle occlusion rate is independent of the CAV lane position in all cases. The complete street scanner is a new technology that realizes the perception of the human settlement environment with the help of the Internet of Vehicles based on 5G communications and sensors. Although there are some shortcomings in the experiment, it still provides an experimental reference for the development of smart vehicles.
  •  
5.
  • Jafri, Syed Hassan Mujtaba, et al. (författare)
  • Conductivity engineering of graphene by defect formation
  • 2010
  • Ingår i: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 43:4, s. 045404-
  • Tidskriftsartikel (refereegranskat)abstract
    • Transport measurements have revealed several exotic electronic properties of graphene. The possibility to influence the electronic structure and hence control the conductivity by adsorption or doping with adatoms is crucial in view of electronics applications. Here, we show that in contrast to expectation, the conductivity of graphene increases with increasing concentration of vacancy defects, by more than one order of magnitude. We obtain a pronounced enhancement of the conductivity after insertion of defects by both quantum mechanical transport calculations as well as experimental studies of carbon nano-sheets. Our finding is attributed to the defect induced mid-gap states, which create a region exhibiting metallic behaviour around the vacancy defects. The modification of the conductivity of graphene by the implementation of stable defects is crucial for the creation of electronic junctions in graphene-based electronics devices.
  •  
6.
  •  
7.
  • Jeong, Seung Hee, 1978-, et al. (författare)
  • Stretchable Thermoelectric Generators Metallized with Liquid Alloy
  • 2017
  • Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 9:18, s. 15791-15797
  • Tidskriftsartikel (refereegranskat)abstract
    • Conventional thermoelectric generators (TEGs) are normally hard, rigid, and flat. However, most objects have curvy surfaces, which require soft and even stretchable TEGs for maximizing efficiency of thermal energy harvesting. Here, soft and stretchable TEGs using conventional rigid Bi2Te3 pellets metallized with a liquid alloy is reported. The fabrication is implemented by means of a tailored layer-by-layer fabrication process. The STEGs exhibit an output power density of 40.6 ?W/cm2 at room temperature. The STEGs are operational after being mechanically stretched-and-released more than 1000 times, thanks to the compliant contact between the liquid alloy interconnects and the rigid pellets. The demonstrated interconnect scheme will provide a new route to the development of soft and stretchable energy-harvesting avenues for a variety of emerging electronic applications.
  •  
8.
  • Shahroozi, Zahra, et al. (författare)
  • Investigation on the extreme peak mooring force distribution of a point absorber wave energy converter with and without a survivability control system
  • 2023
  • Ingår i: Proceedings of the European Wave and Tidal Energy Conference (EWTEC). - : European Wave and Tidal Energy Conference. - 2706-6932 .- 2706-6940. ; 15
  • Tidskriftsartikel (refereegranskat)abstract
    • To determine the optimal design of the wave energy converter (WEC) that can withstand extreme waveconditions, the short- and long-term extreme responses of the system need to be determined. This paper focuses on the extreme peak force distribution of the mooring force for a 1:30 scaled point absorber WEC. The basis of this analysis is the mooring force response obtained from a WEC-Sim model calibrated by wave tank experimental data. The extreme sea states have been chosen from a50-year environmental contour. Here, first, the long-term extreme response using the full sea state approach is obtained for three constant damping cases of the power take-off (PTO) system. Then, using a contour approach, the expected value of the extreme peak line (mooring) force distribution is computed for the sea states along an environmental contour. Further, for the most extremesea state, the extreme peak line force distribution is also computed where a survivability control system, based on a deep neural network (DNN), changes the PTO damping to minimize the peak mooring force in each zero up-crossing episode of surface elevation. The results show that in the absence of a control system, the zero PTO damping case is a conservative choice in the analysis of the long-term response and the design load. For the most extreme sea state along the environmental contour, the survivability control system slightly reduces the expected value of the extreme peak force distribution when compared with lower constant PTO damping configurations.
  •  
9.
  • Shahroozi, Zahra (författare)
  • Neural network survivability approach of a wave energy converter considering uncertainties in the prediction of future knowledge
  • 2024
  • Tidskriftsartikel (refereegranskat)abstract
    • To tune the wave energy converter (WEC) controller parameters such as damping to reduce the line force during extreme wave conditions, future knowledge of the line force is required.To achieve this, the incoming wave and system state should be predicted for a few seconds in the future. It is rather an arduous task to predict the future knowledge of waves and the system's dynamic when dealing with breaking and steep waves, and the system is subject to various nonlinear forces. The classical model-based control strategies often rely on linear assumptions to estimate the WEC dynamics for the sake of simplicity. Unlike the model-based, the data-driven approaches are free from modeling errors and the algorithms are trained over the true and noisy data to predict non-linear system behaviors.Using data-driven approaches, we are able to model nonlinear dynamics. However, new questions emerge on the accuracy of the future wave and system state predictions, and how this uncertainty propagates into the final prediction of the line force. As incorrect damping may lead to excessive line force and detrimental damage to the system, these are the knowledge gaps that need to be addressed.The main purpose of this paper is to answer these questions through a survivability strategy for wave energy converters by providing a realistic perspective on the implementation of the neural network approaches by accounting for the errors in the input data. For this purpose, a series of neural networks is designed that first predicts the surface elevation for 0.36 s ahead, i.e. corresponding to 2 s in the full-scale WEC. This future knowledge of the wave elevation is then used to predict the system state (i.e. power take-off (PTO) translator position) for the same prediction horizon based on the PTO damping. This information is then fed to a convolutional neural network (CNN) that predicts the peak line force 0.36 s ahead. Further, the sensitivity of the peak line force prediction to the uncertainties in the input data and the prediction horizon is analyzed. The neural network models are trained over the experimental data subjected to the extreme sea states for a point absorber wave energy converter. The results present a thorough analysis of the NN models’ performance.The results suggest that the accuracy of the surface elevation prediction has an insignificant independent effect on the peak force prediction model. However, these uncertainties reflect in the PTO translator position prediction, and the model is considerably sensitive to the accuracy of this prediction. This sensitivity nonetheless is less notable for higher PTO damping values. The prediction accuracy of the peak forces dropped by only about 7\% when the predicted input was used in the lower damping cases here, whereas, a larger drop was seen for the higher damping case.  
  •  
10.
  • Beheshtinia, Mohammad Ali, et al. (författare)
  • Prioritizing healthcare waste disposal methods considering environmental health using an enhanced multi-criteria decision-making method
  • 2023
  • Ingår i: Environmental Pollutants and Bioavailability. - : Taylor & Francis Group. - 2639-5932 .- 2639-5940. ; 35:1, s. 250-269
  • Tidskriftsartikel (refereegranskat)abstract
    • The Healthcare Waste Disposal Method Selection (HCWDMS) is a complicated problem due to multiple and often contradictory criteria with different importance degrees. Thus, decision-makers are restored to multi-criteria decision-making (MCDM) methods to prioritize and select the best HCW disposal methods. This study introduces an enhanced MCDM method to deal with the HCWDMS problem. To address the problem, a comprehensive list of criteria and HCW disposal methods are identified. All the criteria are categorized into four main criteria, and Fuzzy Analysis Hierarchy Process is used to determine the weights of considered criteria and sub-criteria. The study results show that environmental, economic, technical, and social criteria are the most important in selecting disposal methods, respectively. Moreover, the sub-criteria of ‘Health Risk’, ‘Release with health effects’, and ‘Capital cost’ have the highest importance, respectively. Additionally, the methods of ‘Microwave’, ‘Sterilization by autoclave’, and ‘Reverse polymerization’ have the highest priority, respectively.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 5544
Typ av publikation
konstnärligt arbete (1)
Typ av innehåll
refereegranskat (5370)
övrigt vetenskapligt/konstnärligt (140)
populärvet., debatt m.m. (34)
Författare/redaktör
Strømme, Maria, 1970 ... (177)
Vitos, Levente (106)
Engqvist, Håkan (97)
Stoica, Peter (94)
Persson, Cecilia (90)
Ahuja, Rajeev (84)
visa fler...
Zhang, Shi-Li (82)
Strömme, Maria (71)
Wigren, Torbjörn (65)
Engqvist, Håkan, 197 ... (61)
Dey, Subhrakanti (53)
Göteman, Malin, 1980 ... (53)
Leijon, Mats (52)
Li, Jian (48)
Zhang, Zhen, 1979- (48)
Primetzhofer, Daniel (47)
Olsson, Jörgen (45)
Johansson, Börje (45)
Jacobson, Staffan (45)
Lv, Zhihan, Dr. 1984 ... (45)
Engström, Jens (45)
Leijon, Mats, 1958 (45)
Gamstedt, E. Kristof ... (44)
Widén, Joakim, 1980- (44)
Svedlindh, Peter (43)
Isaksson, Per (43)
Söderström, Torsten (40)
Cheung, Ocean (40)
Xia, Wei (40)
Stolt, Lars (39)
Edoff, Marika, 1965- (37)
Hjort, Klas (37)
Sjödin, Martin, 1974 ... (37)
Augustine, Robin, 19 ... (37)
Wiklund, Urban (36)
Katardjiev, Ilia (34)
Lei, Qinghua (34)
Höök, Mikael, 1982- (34)
Bernhoff, Hans (33)
Cooray, Vernon (33)
Berg, Sören (33)
Boström, Cecilia (33)
Bardos, Ladislav (33)
Olsson, Mikael (33)
Ahuja, Rajeev, 1965- (32)
Medvedev, Alexander (32)
Zhang, Zhi-Bin (32)
Goude, Anders (32)
Mihranyan, Albert (32)
Edoff, Marika (32)
visa färre...
Lärosäte
Uppsala universitet (5544)
Kungliga Tekniska Högskolan (714)
Chalmers tekniska högskola (153)
Stockholms universitet (110)
Lunds universitet (108)
Linköpings universitet (100)
visa fler...
Luleå tekniska universitet (79)
Sveriges Lantbruksuniversitet (78)
Högskolan Dalarna (63)
Umeå universitet (55)
Göteborgs universitet (52)
Högskolan i Skövde (50)
RISE (48)
Karolinska Institutet (43)
Karlstads universitet (33)
Högskolan i Gävle (32)
Mittuniversitetet (32)
Örebro universitet (28)
Mälardalens universitet (24)
Malmö universitet (12)
Högskolan i Halmstad (9)
Linnéuniversitetet (9)
Försvarshögskolan (9)
Högskolan i Borås (6)
Södertörns högskola (5)
Högskolan Väst (4)
Högskolan Kristianstad (2)
Jönköping University (2)
Handelshögskolan i Stockholm (1)
Gymnastik- och idrottshögskolan (1)
Blekinge Tekniska Högskola (1)
IVL Svenska Miljöinstitutet (1)
visa färre...
Språk
Engelska (5476)
Svenska (60)
Norska (3)
Japanska (2)
Tyska (1)
Ryska (1)
visa fler...
Serbiska (1)
visa färre...
Forskningsämne (UKÄ/SCB)
Naturvetenskap (1512)
Medicin och hälsovetenskap (338)
Samhällsvetenskap (145)
Humaniora (46)
Lantbruksvetenskap (35)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy