Suchergebnisse

ekmekci, ismail/0000-0002-2247-2549; ; WOS: 000570077700012 ; For next generation aircraft, Adaptive Cycle Engine (ACE) is a candidate to fulfill the multi-mission requirements of flight. This new concept is promising to complete deficiencies of conventional low by-pass mixed turbofan engines because the ACE model incorporates different thermodynamic cycles (turbojet and turbofan) on the same air vehicle system. Firstly, performance and design results of the ACE model are compared with those of fixed cycle low by-pass turbofan engine by using specific fuel consumption (SFC), specific thrust (ST), power and efficiency parameters. Moreover, verification of the newly developed ACE model is performed. Secondly, considering some design parameters, ST and SFC values of the ACE model are analyzed for double by-pass mode (DBM) and single by-pass mode (SBM). Considering performance analysis of the ACE, SFC value is determined as 17.85 g/kN.s at DBM and 42.18 g/kN.s at SBM. According to results of energy analysis, overall efficiency of the ACE is calculated as 23% for DBM and 9% for SBM whereas fixed cycle engine has 18% for military mode and 7% for afterburner mode. Finally, minimization of (SFC) is obtained with genetic algorithm approach. Based on the design variables such as by-pass ratio and turbine inlet temperature, minimum SFC value for the ACE model is calculated as 17.41 g/kN.s at DBM and 40.45 g/kN.s at SBM. (C) 2020 Elsevier Ltd. All rights reserved. ; Eskisehir Tehnical University in Turkey; Eskisehir Tehnical University Scientific Research Projects Commission [20DRP056] ; Authors would like to thanks Eskisehir Tehnical University in Turkey for financial and technical support. This study was supported by Eskisehir Tehnical University Scientific Research Projects Commission under the grant no: 20DRP056.

Assessing the dynamics of resilience could help insurers and governments reduce the costs of climate-risk insurance schemes and secure future insurability in the face of an increase in extreme hydro-meteorological events related to climate change.

Purpose
This paper aims to understand why higher education institutions (HEIs) struggle to become sustainable institutions themselves despite providing relevant teaching and research on sustainability.


Design/methodology/approach
Using 17 open-ended, semistructured interviews to determine common themes (codes) regarding sustainability, the authors mapped those codes to the adaptive cycle from social innovation theory.


Findings
Using the adaptive cycle offered a framework for understanding sustainability at HEIs as a cyclical process where innovation occurs in ebbs and flows. Differing perceptions of power by students and faculty slow down the process, and cross-collaboration is the key to further sustainability.


Practical implications
Insights from the adaptive cycle can contribute to HEI assessment of its sustainability initiatives by identifying the stage of the adaptive cycle relevant to the institution's present sustainability work.


Originality/value
Applying the adaptive cycle is an original way of understanding the process of anchoring sustainability at HEIs providing concrete insights into advancing this process.

We used the adaptive cycle as a heuristic to conceptualize the changes in ecosystem services between its phases (growth, conservation, collapse, and reorganization) for Chiloé Island (southern Chile), analyzed as a social-ecological system. We generated hypothetical relationships between services and phases based on literature articles, testing them with secondary databases for 1826– 2016 and interviews with local actors. Results show that the island is currently either in a late conservation phase or already in a collapse phase. Only provisioning ecosystem services corresponded with the proposed phases' relationships, while regulation-maintenance and cultural services showed long-term decreasing trends. We discuss cross-scale interactions and political centralism as the main factors preventing a local adaptive scheme that may start a reorganization phase. ; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1170532 Aparece en contenido como:CONICYT-Chile (Proyecto Fondecyt)

© 2021 The Authors. While mangroves are increasingly described as social-ecological systems (SESs), performing SES research is so much more than merely documenting local resource utilisation patterns in case studies. The aim of this paper is to review and show how ecological, human and institutional resilience could be understood and fostered in an era of uncertainty, through the adaptive cycle (AC) heuristic. Uncertainties come in many forms and shapes: climate change, social and economic dynamics, natural disasters, political and institutional disruption and ever-increasing public demands for participation. Social-ecological studies form windows of experimentation that can provide insights beyond their case-specific context. In order to synthesise and structure the cumulative knowledge base arising from existing and future studies, the need for a suitable overarching framework arose. Here, the AC heuristic represents the connectedness between variables of the mangrove SES versus the mangrove's accumulated capital (natural, built, human and social). We posit that the AC heuristic can be used to interpret spatial and temporal changes (ecological, social, economic, political) in mangrove SESs and we exemplify it by using the 2004 Indian Ocean tsunami as well as a century-long silviculture case. The AC, combined with the SES scheme, allows integration of the spato-temporal dynamics and the multi-dimensional character of mangrove SESs. We also reviewed the ecosystem functions, services and disservices of mangrove SESs, linking each of them to SES capital and variable (fast or slow) attributes, which in turn are closely linked to the different axes and phases of the AC. We call upon mangrove scientists from the natural, applied, social and human sciences to join forces in fitting diversified empirical data from multiple case studies around the world to the AC heuristic. The aim is to reflect on and understand such complex dynamic systems with stakeholders having various (mutual) relationships at risk of breaking down, and to prepare for interactive adaptive planning for mangrove forests. ; Belgian Science Policy Office 'EVAMAB – Economic valuation of ecosystem services in Man & Biosphere Reserves' - BELSPO (BL/58/UN32); Erasmus Mundus Masters Course in Tropical Biodiversity and Ecosystems (TROPIMUNDO); VLIR-UOS-funded GREENDYKE Project (ZEIN2008PR347); BELSPO-funded MAMAFOREST-Project (SR/00/323); ZMT Academy travel grant; Singapore National Parks Board (NParks); TUYF Charitable Trust; HKU Seed Fund for Research; International Coral Reef Initiative (ICRI); UNEP/GEF Blue Forest Project; Pew Charitable Trust; Department of Science and Technology, India INSPIRE Faculty scheme (IFA18-LSPA111);