Search results for "Polygene"
showing 10 items of 14 documents
Inheritance patterns of photoperiodic diapause induction inLeptinotarsa decemlineata
2016
Photoperiod is a reliable indicator of season and an important cue that many insects use for phenological synchronization. Undergoing range expansion insects can face a change in the local photoperiod to which they need to resynchronize. Rapid range expansion can be associated with rapid photoperiodic adaptation, which can be associated with intense selection on strongly heritable polygenic traits. Alternatively, it is proposed that, in insects with an XO sex-determination system, genes with large effect residing on the sex chromosome could drive photoperiodic adaptation because the gene or genes are exposed to selection in the sex carrying only a single X-chromosome. The present study seek…
A novel solar-geothermal trigeneration system integrating water desalination: Design, dynamic simulation and economic assessment
2016
Abstract In this paper, an innovative solar-geothermal polygeneration system is investigated. The system supplies a small community with electricity, desalinated water and space heating and cooling through a district network. The hybrid multi-purpose plant, based on an Organic Rankine Cycle (ORC) supplied by medium-enthalpy geothermal energy and by solar energy; this latter is provided by Parabolic Trough Collectors (PTC). The geothermal brine is first used to drive the ORC loop, then to provide space heating at around 85÷90 °C (in the winter), or cooling (in the summer, by means of a single-effect absorption chiller). Finally, the geothermal brine drives a Multi-Effect Distillation (MED) s…
Promotion of polygeneration for buildings applications through sector- and user-oriented “high efficiency CHP” eligibility criteria
2014
Abstract The eligibility criteria adopted to assess polygeneration plants as “highly efficient” can play a determinant role in favouring or discouraging the market growth of polygeneration systems, especially for buildings applications where economic viability is often more difficult to achieve. Based on the current European framework, in this paper the opportunity to adopt sector- and user-oriented criteria is discussed. After having identified three buildings with different uses (a large hotel, a hospital and an office building), the optimal lay-out and operation strategy of a polygeneration plant serving each building is determined; then, ex-post processing of economic and energetic resu…
A comprehensive tool for efficient design and operation of polygeneration-based energy μgrids serving a cluster of buildings. Part II: Analysis of th…
2013
Abstract The potential of polygeneration systems, in terms of profitability, energy saving and pollutant emissions reduction, highly depends on several factors such as plant efficiency, local normative and tariff conditions and reference technologies adopted to compare the results. In Part I of this paper a reliable tool was described, capable of optimizing the lay-out, design and operation of an integrated polygeneration system serving a cluster of buildings with their heat, cooling and power demand; the tool represents an excellent instrument to perform sensitivity analyses, thus enabling the analyst to formulate general design criteria and predict the effects of any change in the boundar…
A comprehensive tool for efficient design and operation of polygeneration-based energy μgrids serving a cluster of buildings. Part I: Description of …
2013
Polygeneration systems with thermal energy storage represent promising solutions to achieve energy saving and emissions reduction in the civil sector. The definition of customer-oriented design and operation strategies represents a most challenging task, in order to maximize the profitability and make the investment attractive. A large potential is often recognized for the installation of centralized plants serving a cluster of buildings located over a small area; in such cases the design problem becomes extremely complex and the analyst needs reliable instruments to identify the optimal solution. This paper in two parts presents a scientific tool for the optimization of design and operatio…
Trigeneration and Polygeneration Configurations for Desalination and Other Beneficial Processes
2018
Abstract The integration of renewable energy sources (geothermal, biomass, and solar) and desalination systems into novel polygeneration plants is investigated. Two main arrangements are considered: geothermal (GP) and biomass (BP) polygeneration. Both systems include concentrating photovoltaic/thermal solar collectors, a multieffect distillation system for seawater desalination, a single-effect LiBr-H2O absorption chiller, storage tanks, heat exchangers, balance-of-plant devices; a biomass auxiliary heater and geothermal wells are also included, in BP and GP, respectively. The systems can provide electricity and hot water, used for space heating, cooling, domestic hot water production, and…
Recent advances in methods, policies and technologies at sustainable energy systems development
2022
Following the 2015 Paris Agreement and other agreements which have been signed after, sustainable energy development is becoming the major goal in many countries. EU have set the targets to reduce the annual greenhouse gas emission by 40% in 2030 and 80% for 2050 compared with 1990 levels. For achieving this ambitious energy policy, three major technological changes are available: energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Also, for realization cited three major technological changes the support of the multi-disciplinary scientific knowledge is needed. Therefore, from the beginn…
Genetic polymorphism and high detrimental load in natural populations of Drosophila melanogaster from cellar and vineyard
1987
Two Spanish natural populations of Drosophila melanogaster have been analysed with respect to genetic variability in third chromosome viability. The two populations, although from the same locality, belong to relatively different habitats: the inside of a cellar and a vineyard. The patterns of homozygote and heterozygote viability are similar in both populations. The homozygous detrimental loads estimated are very high and the values for the D:L (detrimental/lethal) ratio close to 2.5, which is higher than any previously found. The environmental variance of viability, average degrees of dominance of lethal genes and of viability polygenes and effective population sizes were estimated in eac…
Criteri e metodi per l'ottimizzazione di sistemi di poligenerazione di piccola e media taglia - Criteria and methodologies for the optimization of sm…
2011
L'Unione Europea ha individuato nella produzione combinata di energia elettrica e calore una delle tecnologie ad alta efficienza di maggior interesse, fissando per il 2010 il target del 18% della produzione elettrica totale dell'Unione da sistemi cogenerativi (COM/97/0514). Dati recenti rivelano la non attualità di tale target (al 2005 si è raggiunto il 12% di penetrazione); rimane tuttavia evidente la volontà, esistente sia a livello comunitario che in molti Stati Membri, di perseguire la via della promozione della poligenerazione. Le ragioni di questo interesse sono evidenti: l'elevata efficienza di conversione garantita dal recupero dei cascami termici di un ciclo diretto consente, a par…
OPTIMIZATION OF POLYGENERATION SYSTEMS SERVING A CLUSTER OF BUILDINGS
2012
The optimization of combined energy systems for the production and distribution of warm and cold fluids to civil users is very complex; two possible configurations, i.e. the small single units for individual buildings and the large plants integrated with district heating networks, can be essentially considered, especially in cold climates. Dealing with such a complex problem, involving a very large number of variables, requires efficient algorithms and resolution techniques. The present chapter illustrates a Mixed Integer Linear Program (MILP)1 approach to the optimization of synthesis, design and operation for CHCP-based μ-grids including thermal energy storages. A novel approach is presen…