This article analyses the relationship between PM_(10) concentrations inside and outside two schools in Barreiro,Portugal:Primary School No.5 and D.Luís Mendonça Furtado Basic School.The main objective was t...This article analyses the relationship between PM_(10) concentrations inside and outside two schools in Barreiro,Portugal:Primary School No.5 and D.Luís Mendonça Furtado Basic School.The main objective was to understand the impact of external and internal sources on indoor air quality(IAQ)in school environments.Monitoring campaigns were carried out in different indoor spaces,including classrooms,the gym,and the canteen,and the results were compared with PM_(10) levels outside the building.At Primary School No.5,indoor PM10 concentrations were consistently higher than the outdoor values measured on Avenida do Bocage,with an average Indoor/Outdoor(I/O)ratio of 2.2,indicating a significant impact of indoor activities on particle levels.Similarly,at the D.Luís Mendonça Furtado Basic School,there was an increase in PM_(10) and PM_(2:5) concentrations during school hours,with the highest I/O ratio(3.04)recorded on school days.In the evenings and at weekends,when the spaces were unoccupied,particle concentrations dropped considerably,reaching an I/O ratio of 0.70.Said results suggest that indoor activities are a determining factor for particle levels in indoor air,emphasizing the need for ventilation and pollution control strategies in schools to protect the health of students and staff.展开更多
The use of organic wastes, as an alternative to inorganic fertilizer, can be an important strategy for Brazilian and tropical agriculture. Despite the importance, few field studies have been done for evaluating organi...The use of organic wastes, as an alternative to inorganic fertilizer, can be an important strategy for Brazilian and tropical agriculture. Despite the importance, few field studies have been done for evaluating organic amendments on soybean crops in Brazil. The study aimed to evaluate the residual effects of the organic amendments poultry litter, farmyard manure and biochar combined with mineral fertilizer on some agronomic attributes of a soybean crop. A field experiment was carried out in a split-split-plot scheme, with three replicates in a randomized block experimental design. The organic sources (plots) at rates of 0, 3, 6 and 9 Mg·ha-1 (subplots) combined with 0, 100, 200, 300 and 400 kg·ha-1 (sub subplots) of a mineral fertilizer were applied in 2008. In 2009, only the mineral fertilizer was used on the soybean crop. As a?result, all evaluated attributes were influenced by the treatments, except for the number of grains per pod. The application of poultry litter provided the highest yield (3715 kg·ha-1 using 9 Mg·ha-1 of the source). A synergistic effect between organic amendments and mineral fertilizer was observed. It was found the possibility of decrease doses of mineral fertilizers by prior use of organic amendments. The most effective dose combination application is 5.5 Mg·ha-1 of organic amendments associated with 200 kg·ha-1 of mineral fertilizer to provide optimum yield. The use of organic amendments, rich in nutrients, is a technology to sustainably increase the soybean grain yield.展开更多
This paper analyzes the basic characters of optimum open-pit limit.According to them,following general rule for designing pit limit is obtained.The incremental stripping ratios is not greater than the break-even strip...This paper analyzes the basic characters of optimum open-pit limit.According to them,following general rule for designing pit limit is obtained.The incremental stripping ratios is not greater than the break-even stripping ratios,or the net incremental value is not less than zero.The rule can be used both in traditional and computer methods as direct basis to determine an optimum limit for any kinds of deposit.展开更多
Earth surveillance through aerial images allows more accurate identification and characterization of objects present on the surface from space and airborne platforms.The progression of deep learning and computer visio...Earth surveillance through aerial images allows more accurate identification and characterization of objects present on the surface from space and airborne platforms.The progression of deep learning and computer vision methods and the availability of heterogeneous multispectral remote sensing data make the field more fertile for research.With the evolution of optical sensors,aerial images are becoming more precise and larger,which leads to a new kind of problem for object detection algorithms.This paper proposes the“Sliding Region-based Convolutional Neural Network(SRCNN),”which is an extension of the Faster Region-based Convolutional Neural Network(RCNN)object detection framework to make it independent of the image’s spatial resolution and size.The sliding box strategy is used in the proposed model to segment the image while detecting.The proposed framework outperforms the state-of-the-art Faster RCNN model while processing images with significantly different spatial resolution values.The SRCNN is also capable of detecting objects in images of any size.展开更多
Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in biblio...Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in bibliometrics, Sustainability(a journal outside the discipline) and Scientometrics, the flagship journal in the field.Design/methodology/approach: The study identifies the need for developing tailored tools for improving the quality of thematic bibliometric analyses, and presents a framework that can guide the development of such tools. A total of 508 papers are analysed, 77% of Sustainability, and 23% published in Scientometrics, for the 2019-2021 period.Findings: An average of 2.6 shortcomings per paper was found for the whole sample, with an almost identical number of flaws in both journals. Sustainability has more flaws than Scientometrics in four of the seven parameters studied, while Scientometrics has more shortcomings in the remaining three variables.Research limitations: The first limitation of this work is that it is a study of two scientific journals, so the results cannot be directly extrapolated to the set of thematic bibliometric analyses published in journals from all fields.Practical implications: We propose the adoption of protocols, guidelines, and other similar tools, adapted to bibliometric practice, which could increase the thoroughness, transparency, and reproducibility of this type of research.Originality/value: These results show considerable room for improvement in terms of the adequate use and breakdown of methodological procedures in thematic bibliometric research, both in journals in the Information Science area and journals outside the discipline.展开更多
Radio Frequency IDentification(RFID)and related technologies such as Near Field Communication(NFC)are becoming essential in industrial contexts thanks to their ability to perform contactless data exchange,either devic...Radio Frequency IDentification(RFID)and related technologies such as Near Field Communication(NFC)are becoming essential in industrial contexts thanks to their ability to perform contactless data exchange,either device-to-device or tag-to-device.One of the three main operation modes of NFC,called read/write mode,makes use of the latter type of interaction.It is extensively used in business information systems that make use of NFC tags to provide the end-user with augmented information in one of several available NFC data exchange formats,such as plain text,simple URLs or enriched URLs.Using a wide variety of physical form factors,NFC-compatible tags(wireless transponders)are currently available in many locations with applications going from smart posters,contactless tokens,tap-and-go payments or transport ticketing to automated device configuration,patient identification at hospitals or inventory management within supply chains.Most of these applications handle sensitive processes or data.This paper proposes a complete security threat model for the read/write operation mode of NFC used in Next Generation Industrial IoT(Nx-IIoT)contexts.This model,based on a wellknown methodology,STRIDE,allows developers and users to identify NFC applications vulnerabilities or weaknesses,analyze potential threats,propose risk management strategies,and design mitigation mechanisms to mention only some significant examples.展开更多
Portable diagnostic devices are a viable and low-cost alternative for the detection of pathogens, since they reduce the time of analysis of results availability. Ease of sample collection and quick diagnosis allow thi...Portable diagnostic devices are a viable and low-cost alternative for the detection of pathogens, since they reduce the time of analysis of results availability. Ease of sample collection and quick diagnosis allow this new input to be applied in the diagnosis of the main contaminating microorganisms present in the water. Laboratory tests evaluated the technical viability of the diagnostic device, using commercial strains which were inoculated and optimized in the devices and their growth compared to the conventional method in Petri dishes. Samples of 100 μL bacterial suspension were tested and compared with the traditional sample inoculation method. The device viability was determined by detecting characteristic bacterial colonies in a specific culture medium through the colorimetric development of the obtained colonies. The feasibility assessments allow us to affirm that the device enables both qualitative and quantitative detection of the target bacteria present in liquid samples, and is promising to be applied to assess the quality of water, food and environmental surfaces.展开更多
Mixed ionic electronic conductors(MIECs)have attracted increasing attention as anode materials for solid oxide fuel cells(SOFCs)and they hold great promise for lowering the operation temperature of SOFCs.However,there...Mixed ionic electronic conductors(MIECs)have attracted increasing attention as anode materials for solid oxide fuel cells(SOFCs)and they hold great promise for lowering the operation temperature of SOFCs.However,there has been a lack of understanding of the performance-limiting factors and guidelines for rational design of composite metal-MIEC electrodes.Using a newly-developed approach based on 3 D-tomography and electrochemical impedance spectroscopy,here for the first time we quantify the contribution of the dual-phase boundary(DPB)relative to the three-phase boundary(TPB)reaction pathway on real MIEC electrodes.A new design strategy is developed for Ni/gadolinium doped ceria(CGO)electrodes(a typical MIEC electrode)based on the quantitative analyses and a novel Ni/CGO fiber-matrix structure is proposed and fabricated by combining electrospinning and tape-casting methods using commercial powders.With only 11.5 vol%nickel,the designer Ni/CGO fiber-matrix electrode shows 32%and 67%lower polarization resistance than a nano-Ni impregnated CGO scaffold electrode and conventional cermet electrode respectively.The results in this paper demonstrate quantitatively using real electrode structures that enhancing DPB and hydrogen kinetics are more efficient strategies to enhance electrode performance than simply increasing TPB.展开更多
The goal was to perform the filling,consistency and processing of the rainfall time series data from 1943 to 2013 in five regions of the state.Data were obtained from several sources(ANA,CPRM,INMET,SERLA and LIGHT),to...The goal was to perform the filling,consistency and processing of the rainfall time series data from 1943 to 2013 in five regions of the state.Data were obtained from several sources(ANA,CPRM,INMET,SERLA and LIGHT),totaling 23 stations.The time series(raw data)showed failures that were filled with data from TRMM satellite via 3B43 product,and with the climatological normal from INMET.The 3B43 product was used from 1998 to 2013 and the climatological normal over the 1947-1997 period.Data were submitted to descriptive and exploratory analysis,parametric tests(Shapiro-Wilks and Bartlett),cluster analysis(CA),and data processing(Box Cox)in the 23 stations.Descriptive analysis of the raw data consistency showed a probability of occurrence above 75%(high time variability).Through the CA,two homogeneous rainfall groups(G1 and G2)were defined.The group G1 and G2 represent 77.01%and 22.99%of the rainfall occurring in SRJ,respectively.Box Cox Processing was effective in stabilizing the normality of the residuals and homogeneity of variance of the monthly rainfall time series of the five regions of the state.Data from 3B43 product and the climatological normal can be used as an alternative source of quality data for gap filling.展开更多
In the food production sector,quickly identifying potential hazards is crucial due to the resilience of many pathogens,which could lead to wasted production results and,more severely,epidemic outbreaks.E.coli monitori...In the food production sector,quickly identifying potential hazards is crucial due to the resilience of many pathogens,which could lead to wasted production results and,more severely,epidemic outbreaks.E.coli monitoring is essential;however,traditional quality control methods in fish farming are often slow and intrusive,thus promoting an increase in fish stress and mortality rates.This paper presents an alternative method by utilizing a prototype inspired by polarized optical microscopy(POM),constructed with a Raspberry Pi microprocessor to assess pixel patterns and calculate analyte levels.展开更多
This work evaluates an architecture for decentralized authentication of Internet of Things(IoT)devices in Low Earth Orbit(LEO)satellite networks using IOTA Identity technology.To the best of our knowledge,it is the fi...This work evaluates an architecture for decentralized authentication of Internet of Things(IoT)devices in Low Earth Orbit(LEO)satellite networks using IOTA Identity technology.To the best of our knowledge,it is the first proposal to integrate IOTA’s Directed Acyclic Graph(DAG)-based identity framework into satellite IoT environments,enabling lightweight and distributed authentication under intermittent connectivity.The system leverages Decentralized Identifiers(DIDs)and Verifiable Credentials(VCs)over the Tangle,eliminating the need for mining and sequential blocks.An identity management workflow is implemented that supports the creation,validation,deactivation,and reactivation of IoT devices,and is experimentally validated on the Shimmer Testnet.Three metrics are defined and measured:resolution time,deactivation time,and reactivation time.To improve robustness,an algorithmic optimization is introduced that minimizes communication overhead and reduces latency during deactivation.The experimental results are compared with orbital simulations of satellite revisit times to assess operational feasibility.Unlike blockchain-based approaches,which typically suffer from high confirmation delays and scalability constraints,the proposed DAG architecture provides fast,cost-free operations suitable for resource-constrained IoT devices.The results show that authentication can be efficiently performed within satellite connectivity windows,positioning IOTA Identity as a viable solution for secure and scalable IoT authentication in LEO satellite networks.展开更多
The consumption of contaminated food may cause serious illnesses,and traditional methods to detect Escherichia coli are still associated with long waiting times and high costs given the necessity to transport samples ...The consumption of contaminated food may cause serious illnesses,and traditional methods to detect Escherichia coli are still associated with long waiting times and high costs given the necessity to transport samples to specialized laboratories.There is a need to develop new technologies that allow cheap,fast,and direct monitoring at the site of interest.Thus,in this work,we developed optical immunosensors for the selective detection of E.coli,based on liquid crystal technology,whose molecules can align in different manners depending on the boundary conditions (such as substrates) as well as the environment that they experience.Each glass substrate was functionalized with anti-E.coli antibody using cysteamine as an intermediate,and a vertical alignment was imposed on the liquid crystal molecules by using DMOAP during functionalization.The presence of bacteria disrupts the alignment of the liquid crystal molecules,changing the intensity of light emerging between cross polarizers,measured using a polarized optical microscope and a monochromator.It was possible to detect E.coli in suspensions in the concentration range from 2.8 cells/mL to 2.8×10^(9) cells∕mL.Selectivity was also evaluated,and the sensors were used to analyze contaminated water samples.A prototype was developed to allow faster,in-situ,and easier analysis avoiding bulky instruments.展开更多
文摘This article analyses the relationship between PM_(10) concentrations inside and outside two schools in Barreiro,Portugal:Primary School No.5 and D.Luís Mendonça Furtado Basic School.The main objective was to understand the impact of external and internal sources on indoor air quality(IAQ)in school environments.Monitoring campaigns were carried out in different indoor spaces,including classrooms,the gym,and the canteen,and the results were compared with PM_(10) levels outside the building.At Primary School No.5,indoor PM10 concentrations were consistently higher than the outdoor values measured on Avenida do Bocage,with an average Indoor/Outdoor(I/O)ratio of 2.2,indicating a significant impact of indoor activities on particle levels.Similarly,at the D.Luís Mendonça Furtado Basic School,there was an increase in PM_(10) and PM_(2:5) concentrations during school hours,with the highest I/O ratio(3.04)recorded on school days.In the evenings and at weekends,when the spaces were unoccupied,particle concentrations dropped considerably,reaching an I/O ratio of 0.70.Said results suggest that indoor activities are a determining factor for particle levels in indoor air,emphasizing the need for ventilation and pollution control strategies in schools to protect the health of students and staff.
文摘The use of organic wastes, as an alternative to inorganic fertilizer, can be an important strategy for Brazilian and tropical agriculture. Despite the importance, few field studies have been done for evaluating organic amendments on soybean crops in Brazil. The study aimed to evaluate the residual effects of the organic amendments poultry litter, farmyard manure and biochar combined with mineral fertilizer on some agronomic attributes of a soybean crop. A field experiment was carried out in a split-split-plot scheme, with three replicates in a randomized block experimental design. The organic sources (plots) at rates of 0, 3, 6 and 9 Mg·ha-1 (subplots) combined with 0, 100, 200, 300 and 400 kg·ha-1 (sub subplots) of a mineral fertilizer were applied in 2008. In 2009, only the mineral fertilizer was used on the soybean crop. As a?result, all evaluated attributes were influenced by the treatments, except for the number of grains per pod. The application of poultry litter provided the highest yield (3715 kg·ha-1 using 9 Mg·ha-1 of the source). A synergistic effect between organic amendments and mineral fertilizer was observed. It was found the possibility of decrease doses of mineral fertilizers by prior use of organic amendments. The most effective dose combination application is 5.5 Mg·ha-1 of organic amendments associated with 200 kg·ha-1 of mineral fertilizer to provide optimum yield. The use of organic amendments, rich in nutrients, is a technology to sustainably increase the soybean grain yield.
文摘This paper analyzes the basic characters of optimum open-pit limit.According to them,following general rule for designing pit limit is obtained.The incremental stripping ratios is not greater than the break-even stripping ratios,or the net incremental value is not less than zero.The rule can be used both in traditional and computer methods as direct basis to determine an optimum limit for any kinds of deposit.
文摘Earth surveillance through aerial images allows more accurate identification and characterization of objects present on the surface from space and airborne platforms.The progression of deep learning and computer vision methods and the availability of heterogeneous multispectral remote sensing data make the field more fertile for research.With the evolution of optical sensors,aerial images are becoming more precise and larger,which leads to a new kind of problem for object detection algorithms.This paper proposes the“Sliding Region-based Convolutional Neural Network(SRCNN),”which is an extension of the Faster Region-based Convolutional Neural Network(RCNN)object detection framework to make it independent of the image’s spatial resolution and size.The sliding box strategy is used in the proposed model to segment the image while detecting.The proposed framework outperforms the state-of-the-art Faster RCNN model while processing images with significantly different spatial resolution values.The SRCNN is also capable of detecting objects in images of any size.
文摘Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in bibliometrics, Sustainability(a journal outside the discipline) and Scientometrics, the flagship journal in the field.Design/methodology/approach: The study identifies the need for developing tailored tools for improving the quality of thematic bibliometric analyses, and presents a framework that can guide the development of such tools. A total of 508 papers are analysed, 77% of Sustainability, and 23% published in Scientometrics, for the 2019-2021 period.Findings: An average of 2.6 shortcomings per paper was found for the whole sample, with an almost identical number of flaws in both journals. Sustainability has more flaws than Scientometrics in four of the seven parameters studied, while Scientometrics has more shortcomings in the remaining three variables.Research limitations: The first limitation of this work is that it is a study of two scientific journals, so the results cannot be directly extrapolated to the set of thematic bibliometric analyses published in journals from all fields.Practical implications: We propose the adoption of protocols, guidelines, and other similar tools, adapted to bibliometric practice, which could increase the thoroughness, transparency, and reproducibility of this type of research.Originality/value: These results show considerable room for improvement in terms of the adequate use and breakdown of methodological procedures in thematic bibliometric research, both in journals in the Information Science area and journals outside the discipline.
文摘Radio Frequency IDentification(RFID)and related technologies such as Near Field Communication(NFC)are becoming essential in industrial contexts thanks to their ability to perform contactless data exchange,either device-to-device or tag-to-device.One of the three main operation modes of NFC,called read/write mode,makes use of the latter type of interaction.It is extensively used in business information systems that make use of NFC tags to provide the end-user with augmented information in one of several available NFC data exchange formats,such as plain text,simple URLs or enriched URLs.Using a wide variety of physical form factors,NFC-compatible tags(wireless transponders)are currently available in many locations with applications going from smart posters,contactless tokens,tap-and-go payments or transport ticketing to automated device configuration,patient identification at hospitals or inventory management within supply chains.Most of these applications handle sensitive processes or data.This paper proposes a complete security threat model for the read/write operation mode of NFC used in Next Generation Industrial IoT(Nx-IIoT)contexts.This model,based on a wellknown methodology,STRIDE,allows developers and users to identify NFC applications vulnerabilities or weaknesses,analyze potential threats,propose risk management strategies,and design mitigation mechanisms to mention only some significant examples.
基金This work was supported by the Empresa Brasileira de Pesquisa Agropecuária(EMBRAPA)and the Fundacao Universidade Federal de Rondônia(UNIR)specially to the Environmental Biogeochemistry Wolfgang C.Pfeiffer Research Groupwhich provided laboratory space and supplies for carrying out the research.The first author also thanks the Fundacao de AmparoàPesquisa de Rondônia(FAPERO)for the financial support granted through a scholarship(MSc and PhD scholarship program-MS/DR-CALL 010/2016).
文摘Portable diagnostic devices are a viable and low-cost alternative for the detection of pathogens, since they reduce the time of analysis of results availability. Ease of sample collection and quick diagnosis allow this new input to be applied in the diagnosis of the main contaminating microorganisms present in the water. Laboratory tests evaluated the technical viability of the diagnostic device, using commercial strains which were inoculated and optimized in the devices and their growth compared to the conventional method in Petri dishes. Samples of 100 μL bacterial suspension were tested and compared with the traditional sample inoculation method. The device viability was determined by detecting characteristic bacterial colonies in a specific culture medium through the colorimetric development of the obtained colonies. The feasibility assessments allow us to affirm that the device enables both qualitative and quantitative detection of the target bacteria present in liquid samples, and is promising to be applied to assess the quality of water, food and environmental surfaces.
基金the financial support from EPSRC(EP/P024807/1,EP/M014045/1,EP/S000933/1 and EP/N009924/1)by the EPSRC energy storage for low carbon grids project(EP/K002252/1)+3 种基金the EPSRC Joint UK-India Clean Energy center(JUICE)(EP/P003605/1)the Integrated Development of Low-Carbon Energy Systems(IDLES)project(EP/R045518/1)the Innovate UK BAFTA project,the Innovate UK for Advanced Battery Lifetime Extension(ABLE)project for funding underthe China Scholarship Council。
文摘Mixed ionic electronic conductors(MIECs)have attracted increasing attention as anode materials for solid oxide fuel cells(SOFCs)and they hold great promise for lowering the operation temperature of SOFCs.However,there has been a lack of understanding of the performance-limiting factors and guidelines for rational design of composite metal-MIEC electrodes.Using a newly-developed approach based on 3 D-tomography and electrochemical impedance spectroscopy,here for the first time we quantify the contribution of the dual-phase boundary(DPB)relative to the three-phase boundary(TPB)reaction pathway on real MIEC electrodes.A new design strategy is developed for Ni/gadolinium doped ceria(CGO)electrodes(a typical MIEC electrode)based on the quantitative analyses and a novel Ni/CGO fiber-matrix structure is proposed and fabricated by combining electrospinning and tape-casting methods using commercial powders.With only 11.5 vol%nickel,the designer Ni/CGO fiber-matrix electrode shows 32%and 67%lower polarization resistance than a nano-Ni impregnated CGO scaffold electrode and conventional cermet electrode respectively.The results in this paper demonstrate quantitatively using real electrode structures that enhancing DPB and hydrogen kinetics are more efficient strategies to enhance electrode performance than simply increasing TPB.
基金The authors acknowledge the Agência Nacional deÁguas(ANA),Companhia de Pesquisa de Recursos Minerais(CPRM)Instituto Nacional de Meteorologia(INMET)+2 种基金SERLA Fundação Superintendência Estadual de Rios e Lagoas and Light Serviços de Eletricidade S/A by gently give in the data for composing the rainfall time seriesthe CAPES for granting Doctorate scholarshipThe second author thanks Brazilian National Council for Scientific and Technological Development(CNPq)for granting the Research Productivity Fellowship level 2(309681/2019-7).
文摘The goal was to perform the filling,consistency and processing of the rainfall time series data from 1943 to 2013 in five regions of the state.Data were obtained from several sources(ANA,CPRM,INMET,SERLA and LIGHT),totaling 23 stations.The time series(raw data)showed failures that were filled with data from TRMM satellite via 3B43 product,and with the climatological normal from INMET.The 3B43 product was used from 1998 to 2013 and the climatological normal over the 1947-1997 period.Data were submitted to descriptive and exploratory analysis,parametric tests(Shapiro-Wilks and Bartlett),cluster analysis(CA),and data processing(Box Cox)in the 23 stations.Descriptive analysis of the raw data consistency showed a probability of occurrence above 75%(high time variability).Through the CA,two homogeneous rainfall groups(G1 and G2)were defined.The group G1 and G2 represent 77.01%and 22.99%of the rainfall occurring in SRJ,respectively.Box Cox Processing was effective in stabilizing the normality of the residuals and homogeneity of variance of the monthly rainfall time series of the five regions of the state.Data from 3B43 product and the climatological normal can be used as an alternative source of quality data for gap filling.
基金European Commission(CZ.10.03.01/00/22-003/0000048)Fundacao para a Ciencia e a Tecnologia(PTDC/EEI-EEE/0415/2021),CICECO(UIDB/50011/2020,UIDP/50011/2020,LA/P/0006/2020)+1 种基金VSB-Technical University of Ostrava(SP2025/039)FCT/MCTES(UI/BD/153066/2022)。
文摘In the food production sector,quickly identifying potential hazards is crucial due to the resilience of many pathogens,which could lead to wasted production results and,more severely,epidemic outbreaks.E.coli monitoring is essential;however,traditional quality control methods in fish farming are often slow and intrusive,thus promoting an increase in fish stress and mortality rates.This paper presents an alternative method by utilizing a prototype inspired by polarized optical microscopy(POM),constructed with a Raspberry Pi microprocessor to assess pixel patterns and calculate analyte levels.
基金This work is part of the‘Intelligent and Cyber-Secure Platform for Adaptive Optimization in the Simultaneous Operation of Heterogeneous Autonomous Robots(PICRAH4.0)’with reference MIG-20232082,funded by MCIN/AEI/10.13039/501100011033supported by the Universidad Internacional de La Rioja(UNIR)through the Precompetitive Research Project entitled“Nuevos Horizontes en Internet de las Cosas y NewSpace(NEWIOT)”,reference PP-2024-13,funded under the 2024 Call for Research Projects.
文摘This work evaluates an architecture for decentralized authentication of Internet of Things(IoT)devices in Low Earth Orbit(LEO)satellite networks using IOTA Identity technology.To the best of our knowledge,it is the first proposal to integrate IOTA’s Directed Acyclic Graph(DAG)-based identity framework into satellite IoT environments,enabling lightweight and distributed authentication under intermittent connectivity.The system leverages Decentralized Identifiers(DIDs)and Verifiable Credentials(VCs)over the Tangle,eliminating the need for mining and sequential blocks.An identity management workflow is implemented that supports the creation,validation,deactivation,and reactivation of IoT devices,and is experimentally validated on the Shimmer Testnet.Three metrics are defined and measured:resolution time,deactivation time,and reactivation time.To improve robustness,an algorithmic optimization is introduced that minimizes communication overhead and reduces latency during deactivation.The experimental results are compared with orbital simulations of satellite revisit times to assess operational feasibility.Unlike blockchain-based approaches,which typically suffer from high confirmation delays and scalability constraints,the proposed DAG architecture provides fast,cost-free operations suitable for resource-constrained IoT devices.The results show that authentication can be efficiently performed within satellite connectivity windows,positioning IOTA Identity as a viable solution for secure and scalable IoT authentication in LEO satellite networks.
基金OstravskáUniverzita v Ostravě(CZ.10.03.01/00/22_003/0000048)Fundacao para a Ciência e a Tecnologia(LA/P/0006/2020,UIDB/50011/2020 UIDP/50011/2020,LA/P/0037/2020,UIDB/50025/2020,UIDP/50025/2020,PTDC/EEI-EEE/0415/2021,UI/BD/153066/2022,UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020)。
文摘The consumption of contaminated food may cause serious illnesses,and traditional methods to detect Escherichia coli are still associated with long waiting times and high costs given the necessity to transport samples to specialized laboratories.There is a need to develop new technologies that allow cheap,fast,and direct monitoring at the site of interest.Thus,in this work,we developed optical immunosensors for the selective detection of E.coli,based on liquid crystal technology,whose molecules can align in different manners depending on the boundary conditions (such as substrates) as well as the environment that they experience.Each glass substrate was functionalized with anti-E.coli antibody using cysteamine as an intermediate,and a vertical alignment was imposed on the liquid crystal molecules by using DMOAP during functionalization.The presence of bacteria disrupts the alignment of the liquid crystal molecules,changing the intensity of light emerging between cross polarizers,measured using a polarized optical microscope and a monochromator.It was possible to detect E.coli in suspensions in the concentration range from 2.8 cells/mL to 2.8×10^(9) cells∕mL.Selectivity was also evaluated,and the sensors were used to analyze contaminated water samples.A prototype was developed to allow faster,in-situ,and easier analysis avoiding bulky instruments.
