Search results for " engineering"

Electrical conductivity of glass fiber-reinforced plastic with nanomodified matrix for damage diagnostic

2021

The electrical conductivity of glass fiber-reinforced plastic (GFRP) with epoxy matrix modified by multiwall carbon nanotubes (MWCNT) was studied. The electrical conductivity of nanomodified lamina and multi-layered GFRP was investigated on several levels using a structural approach. Components of the electrical conductivity tensor for unidirectional-reinforced monolayer were calculated similarly as in micromechanics using the conductivity of the nanomodified matrix. The electrical conductivity of multilayer composite was calculated using laminate theory and compared with values measured experimentally for various fiber orientation angles. Calculated and experimental data were in good agree…

Decoupled control scheme of grid-connected split-source inverters

2017

Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, e.g., the high efficiency, the reduced cost and complexity, and, quite often, the boost capabilities that is usually achieved using a front-end dc–dc boost converter before the inversion stage, leading to a two-stage architecture. Meanwhile, single-stage power conversion systems, which perform the boosting operation within the inversion one, offer some potential advantages, in terms of reducing the complexity and the volume of the whole system. Among several proposed options, the split-source inverter (SSI) has been recently proposed by Abdelhakim et al. as an alternative option with some…

Cybersecurity Attacks on Software Logic and Error Handling Within ADS-B Implementations: Systematic Testing of Resilience and Countermeasures

2022

Automatic Dependent Surveillance-Broadcast (ADS-B) is a cornerstone of the next-generation digital sky and is now mandated in several countries. However, there have been many reports of serious security vulnerabilities in the ADS-B architecture. In this paper, we demonstrate and evaluate the impact of multiple cyberattacks on ADS-B via remote radio frequency links that affected various network, processing, and display subsystems used within the ADS-B ecosystem. Overall we implemented and tested 12 cyberattacks on ADS-B in a controlled environment, out of which 5 attacks were presented or implemented for the first time. For all these attacks, we developed a unique testbed that consisted of 1…

Developing response-ability in human-wasp encounters

2023

Learning to live with unloved others is crucial in the ecological crisis. Unloved wasps are feared and disliked for their sting. Understanding of their ecological importance is increasing, however. Human-wasp encounters are changing with environmental changes, and strategies for multispecies cohabitation are needed. This multispecies study highlights features of wasp biology affecting human-wasp encounters and analyzes how conflicted human-wasp relations could be mitigated. The geographical focus is Finland, in the Northern boreal region. Biological analysis specified spatiotemporal aspects affecting human-wasp encounters: human and wasp habitats and preferences overlap ubiquitously. From a…

Force transmission and interactions between synergistic muscles

2023

The classical view of muscles as independent motors has been challenged over the past decades. An alternative view has emerged in which muscles are not isolated but embedded in a three-dimensional connective tissue network that links them to adjacent muscles and other non-muscular structures in the body. Animal studies showing that the forces measured at the distal and proximal ends of a muscle are not equal have provided undisputable evidence that these connective tissue linkages are strong enough to serve as an extra pathway for muscular force transmission. In this historical review, we first introduce the terminology and anatomy related to these pathways of muscle force transmission and …

Intentiolähtöinen lähestymistapa käytettävyyttä koskevien vaatimusten määrittelyyn : kuluttajamarkkinoille suunnatun innovatiivisen ohjelmistotuottee…

2012

Sysmä Community Currency: An Analysis of its Success from the Perspectives of Purposes, Stakeholders and Promotion

2019

Artikkeli on tapaustutkimus paikallisrahajärjestelmästä, jota kokeiltiin äskettäin maalaisympäristössä Sysmän kunnassa. Paikallisraha on yksi innovaatiivisista aloitteista, joita kunta on tehnyt tällä vuosituhannella torjuakseen jo 1960-luvulta alkaen käynnissä ollutta väestökatoa. Tässä artikkelissa tutkitaan paikallisrahan käynnistysvaihetta siihen sisältyneiden ristiriitojen näkökulmasta. Artikkelissa todetaan, että järjestelmä kärsi epäselvästä tavoitteenasettelusta, ja että eri osallisilla oli tavoittesta vaihtelevia ja ristiriitaisia käsityksiä. Paikallisrahan sosiaalista hyväksyntää heikensivät päätös rajoittaa rahaa vastaanottavien yritysten joukko kunnassa kirjoilla oleviin yrityks…

Physico-Chemical Properties and Use of Waste Biomass-Derived Activated Carbons

2017

Activated carbons are widely used in different industrial processes for example as adsorbents or as support materials. Advantageously these carbons can be prepared from residual or waste biomass materials. Different raw material type and activation procedure plays an important role in the physico-chemical characteristics of activated carbon e.g. surface area, porosity and pore distribution. In this study, activated carbon has been prepared from lignocellulosic waste materials (e.g. saw dust, lignin residue) and characterized by a number of methods. Further, adsorption properties of carbons were evaluated. Adsorption capacity of dyes and metals was high (methylene blue dye 86 % and zinc meta…

Waste heat recovery from a marine waste incinerator using a thermoelectric generator

2012

Published version of an article published in the journal: Journal of Electronic Materials. Also available from the publisher at: http://dx.doi.org/10.1007/s11664-012-2009-6 A marine waste incinerator has been evaluated for waste heat harvesting using thermoelectric generators (TEG). The application has been evaluated using mathematical modeling to optimize the heat exchanger and some vital design parameters of the TEG. The calculation shows that it is possible to extract 58 kW el at a price of 6.6 US$/W from an 850-kW th incinerator when optimizing for maximum power. However, minimizing the cost, it is possible to get 25 kW el at a price of 2.5 US$/W. A trade-off between the two targets lea…

Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems

2007

The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The results indicated the feasibility of the UASB-septic tank for (pre)treatment of black water at low temperatures with respect to removal of suspended solids and dissolved organic material. Inoculum sludge had little effect on COD(ss) removal, though in the start-up phase some poorly adapted inoculum disintegrated and washed out, thus requiring consideration when designing the process. Removal of …