Search results for "Renewable"
showing 10 items of 2395 documents
IEA EBC Annex83 Positive Energy Districts
2021
At a global level, the need for energy efficiency and an increased share of renewable energy sources is evident, as is the crucial role of cities due to the rapid urbanization rate. As a consequence of this, the research work related to Positive Energy Districts (PED) has accelerated in recent years. A common shared definition, as well as technological approaches or methodological issues related to PEDs are still unclear in this development and a global scientific discussion is needed. The International Energy Agency’s Energy in Buildings and Communities Programme (IEA EBC) Annex 83 is the main platform for this international scientific debate and research. This paper describes the challeng…
Pathways for the amplification of agroecology in African sustainable urban agriculture
2020
A growing awareness that highly intensified agricultural systems have made a substantial worldwide contribution to the worsening of the resilience capacity of natural ecosystems has, over the last twenty years, brought general attention to agroecological management models. This aspect is even more evident in industrial agriculture, which is based on the use of multiple chemical products derived from non-natural synthesis. In more developed countries, a new idea of ecology linked to agricultural production has been increasingly developed and, for this reason, there has been a greater diffusion of differentiated agricultural models taking into consideration the environmental impact of product…
An Economic Assessment of Micro-Scale Use of Renewable Energy Sources: Two Case Studies
2015
During recent times, renewable energy technologies have shown a relative fast growth in the global energy investment, global energy capacity and their integration within multiple sectors, particularly in the electricity sector. Renewable energy technologies have also experienced notorious declining costs on their manufacturing production. Nevertheless, while this growth is widely acknowledged, the share of renewables with respect total energy production has been moderate. Technological advancements in renewable energy have demonstrated the potential of renewables in energy generation and also that renewables can provide direct and indirect advantages over their counterparts. This thesis inv…
Applicability of hybrid aspen (Populus tremula L. × P. tremuloides Michx.) bark extract as a precursor of rigid carbon foam and activated carbon
2023
Hybrid aspens have long attracted scientific interest, but the research on their use as feedstocks for chemical applications are still very limited. The bark biomass of the poplar species contains many valuable extractives that can be utilized as value-added products. This paper examines the applicability of hybrid aspen (Populus tremula L. × P. tremuloides Michx.) bark extract as a precursor of rigid carbon foam and activated carbon. To explore this, the study considers 1) the basic chemical composition of the bark in terms of added value potential, 2) the basic chemical composition of the bark extract and the effect of its pretreatment on the extract composition, 3) the production of rigi…
Roczna wydajność instalacji PV zamontowanej na dachu budynku dydaktycznego Uniwersytetu Opolskiego
2018
Celem badań była analiza i ocena sprawności pracy instalacji fotowoltaicznej zamontowanej na dachu budynku dydaktycznego Uniwersytetu Opolskiego mieszczącego się przy ul. Kominka 6 w Opolu. Zakres pracy obejmował ocenę: energetyczną - uzysku energetycznego (ilość wyprodukowanego prądu a położenie geograficzne paneli fotowoltaicznych) i ekologiczną - redukcja emisji szkodliwych substancji niewyemitowanych do aerozolu atmosferycznego z powodu produkcji prądu przez instalację PV, a niedostarczonej przez elektrownię opalaną węglem. Badania wykazały dobry wynik uzysku energetycznego w ciągu roku - 5,30 MWh energii z tego systemu oraz znaczną redukcję emisji CO2 do atmosfery - 4,27 Mg/rok, co pot…
An intergenerational competency framework : Competencies for knowledge sustainability and start‐up development in the digital age
2022
In this study, we looked at the competencies and changes in the competency spectrum required for global start-ups in the digital age. Specifically, we explored intergenerational collaboration as an intervention in which experienced business-people from senior adult groups support young entrepreneurs. We conducted a Delphi study with 20 experts from different disciplines, considering the study context. The results of this study shed light on understanding the necessary competencies of entrepreneurs for intergenerationally supported start-up innovation by providing 27 competencies categorized as follows: intergenerational safety facilitation, cultural awareness, virtues for growth, effectual …
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…
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 …
The role of microbial ecology during biogas production from renewable energy sources. Characterizing microbial community structures in bioenergy prod…
2019
La Microbiología tiene un rol fundamental en la integración de procesos para la recuperación de nutrientes, energía y agua durante el tratamiento biológico del agua residual. La identificación de los grupos microbiológicos clave, así como de sus dinámicas, ecología y estructuras microbianas, mejorará el entendimiento de los procesos que integran las futuras plantas de recuperación de recursos, conocidas por sus siglas en inglés como Water Resource Recovery Facilities (WRRF). Este conocimiento podría ser de gran utilidad durante la optimización de sistemas anaerobios que recuperan energía a partir de fuentes de biomasa renovables. Hasta la fecha, diferentes estudios han demostrado que la com…
A Comparative Eye Tracking Study of Usability—Towards Sustainable Web Design
2021
Websites are one of the most frequently used communication environments, and creating sustainable web designs should be an objective for all companies. Ensuring high usability is proving to be one of the main contributors to sustainable web design, reducing usage time, eliminating frustration and increasing satisfaction and retention. The present paper studies the usability of different website landing pages, seeking to identify the elements, structures and designs that increase usability. The study analyzed the behavior of 22 participants during their interaction with five different landing pages while they performed three tasks on the webpage and freely viewed each page for one minute. Th…