303 research outputs found
Baseline marine benthic surveys in the Maltese Islands (Central Mediterranean)
Extract from: MEDCOAST 97 : Proceedings of the Third International Conference on the Mediterranean Coastal Environment, Qawra, Malta / E. Ozhan (editor), (1997)During the period 1991 to 1997, extensive baseline studies of the submarine
geomorphology, infralittoral habitats, macrobenthic assemblages, and demersal fish
fauna, were carried out in 14 different sites around the Maltese Islands, using
conventional SCUBA diving techniques. These were made as part of assessments of the
environmental impact of existing or proposed projects, or in order to produce an inventory
of coastal resources. In total, these surveys covered a sea-bed area of ca. 7.55Km² and
a coastline length of ca 24 km, and represent the most extensive biological surveys
of the marine environment carried out to date in the Maltese Islands. The results of these
surveys have been presented as maps showing the type, location, and spatial extent of
these physical and biological features. The Peres & Picard (1964) scheme, as adapted
by Pen~s (1967; 1982) was used to classify and characterize the benthic assemblages
recorded during the surveys.
Our results show that, in tenus of spatial extent, the most important
macrobenthic assemblages are the communities of photophilic 'algae on hard substrata,
meadows of the sea-grass Posidonia oceanica and communities of bare well-sorted
sand. For all these, many subtypes and facies exist, depending on the light intensity,
hydrodynamic conditions, microtopography, sediment granulometry and other edaphic
factors, and anthropic influences, including pollution.
Other assemblages with a limited spatial distribution include meadows of the
sea-grass (vmodocea nodosa and of the Lessepsian immigrant Halophila stipu/acea on
sandy bottoms, the assemblages of boulder fields which are complexes of photophilic
and sciaphilic communities, and those of marine caves. Our maps are supplemented by
descriptions of the different habitats and macrobenthjc assemblages, species lists, and
semi-quantitative data on percentage cover for the dominant macroalgae, shoot density
counts for sea-grass meadows, and population density counts for the main macrofaunal
species.
These maps and data-sets are intended to be used (i) for assessing the status of
habitats, species assemblages, and individual species, around the Maltese Islands in
order to recommend appropriate measures for their conservation, including inclusion in
red data lists; (ii) for designation of marine protected areas; and (iii) as baselines against
which future monitoring studies and surveys can be compared.peer-reviewe
Genetic basis of between-individual and within-individual variance of docility
Funded by Alces Software UCLA Academic Senate Division of Life Sciences National Geographic Society National Science Foundation. Grant Numbers: IDBR-0754247, DEB-1119660, DBI-0242960, DBI-0731346 University of Aberdeen Data deposited at Dryad: doi:10.5061/dryad.11vf0.Peer reviewedPostprin
Environmental consequences of Maltese MSW incineration
The intensity of Municipal Solid Waste (MSW) generation by human and economic activities causes
environmental impacts, particularly critical in small insular countries, such as Malta. Thus, an investigation of
the potential of Maltese MSW incineration with energy recovery was performed in this work focused on
thermodynamic and land use aspects. The electricity potential of an MSW incinerator with associated electrical
power plant to be built in Malta can be estimated as 5% of the total energy consumed in 2010 in the
archipelago; alternatively, in a CHP configuration, it can also supply all the thermal energy required in 2010 for
Multi-Effect Desalination. During its lifespan the plant can reduce deposition in landfills by at least 270,000 m2
(0.09% of the archipelago total area), diminishing also the potential for water and soil contamination. Last but
not least, it can contribute to decrease the dependence on imported fossil fuels
Energy recovery and impact on land use of Maltese municipal solid waste incineration
An investigation of the potential of Maltese Municipal Solid Waste (MSW) for energy recovery is carried in this work together with a preliminary assessment of the corresponding economic and land use impacts. MSW composition data was collected to evaluate the waste combustion enthalpy. Data from 1997 to 2010 allowed the conclusion that an incinerator with a capacity of 32,500kg/h can treat all the waste expectably generated in Malta during next 20 years. The thermodynamics of the steam cycle combined with elemental analysis were applied to study the contribution for power (PG) and Combined Heat and Power (CHP) generation. The thermal energy was analyzed assuming its use in desalination. The best scenario considered corresponds to a potential electric power of 10 MW (PG) or to a maximum 4.8 million m3/year of desalinated water combined with and 7.25 MW (CHP). It was concluded that incineration and CHP have the greatest potential to maximize revenues, due to the optimal combination of heat production and electricity generation. Finally, a calculation of the savings in land use due to the MSW incineration implementation was performed. Those savings could represent from 13,500 to 17,000 m2 per year, a decisive benefit for Malta.The authors acknowledge the financial support of IPC through project PEst-C/CTM/LA0025/2011 (Strategic Project-LA 25-2011-2012) for the execution of the work described herein. The work would not have been possible without the support of various individuals and institutions in Portugal and in the Maltese islands. In Portugal, we are grateful for the information provided by LIPOR - Central de Valorizacao Energetica, at Maia, which allowed us to validate the incineration data gathered in the literature. Our sincere thanks are also addressed to Prof. Toste de Azevedo, Viriato Semiao, Zdena Zsigraiova, Gilberto Tavares and Rui Martins, of the Mechanical Engineering Department at the Instituto Superior Tecnico, who helped us with the thermodynamic calculations and with other important incineration related information. We acknowledge the help of Prof. Godfrey Pirotta, Edward Mallia, Tonio Sant and Maria Attard of the University of Malta for their availability to explain and contextualize the islands' energy and environment policies. Finally, the assistance of WasteServ Malta Corporation, which provided actual information about MSW generation and further details about the Maltese waste management system, should also be acknowledged
Central place foragers and moving stimuli : a hidden-state model to discriminate the processes affecting movement
We thank Orkney Islands Council for access to Eynhallow and Talisman Energy (UK) Ltd for fieldwork and equipment support. Marine Scotland provided access to anonymized VMS data. Handling and tagging of fulmars was conducted under licenses from the British Trust for Ornithology and the UK Home Office. EE was funded by a Marine Alliance for Science and Technology for Scotland/University of Aberdeen College of Life Sciences and Medicine studentship. We are grateful to Jason Matthiopoulos, Thomas Cornulier, Beth Scott, David Lusseau, Julien Martin and Tiago Marques for suggestions on model development, and to the many colleagues who assisted with fieldwork. We thank Emer Rogan and University College Cork for providing desk space to EP. Finally, we thank Editor-in-Chief Ben Sheldon, Associate Editor Luca Borger and three anonymous reviewers for their useful comments on the paper. Data available from the Dryad Digital Repository: https://doi:10.5061/dryad.0d377r6 (Pirotta et al., 2018)Peer reviewedPostprintPostprintPostprintPostprin
Potential for energy recovery from maltese MSW: a thermodynamic analysis
An investigation of the Maltese Municipal Solid Waste (MSW) potential for energy recovery is carried in this work. In a first step, MSW composition data was collected to evaluate the waste combustion enthalpy by a weighted average of each fraction, using the corresponding Low Heat Value (LHV). Results indicate that each kilogram of Maltese MSW releases circa 8,726 kJ of energy when combusted. Data from 1997 to 2009 allowed the conclusion that an incinerator with a capacity of 32.5 tonnes per hour can treat the waste expectably generated in Malta during the plant life span. In a second step, MSW elemental analysis was used to evaluate (i) the necessary stoichiometric air (152.4%) and (ii) the temperature of the flue gas (915.5 ºC), respecting the 6% ratio (voxygen/vfluegas) imposed by EU regulations. Finally, the thermodynamics of the steam cycle was applied to study the possible contribution of energy recovery for electrical power generation (PG) and co-generation (CHP). The thermal energy was analyzed assuming its use in desalination (multi effect distillation, MED), by means of the so-called gain output ratio (GOR) index. The final results lead to a potential power of 10 MW (PG) or a minimum of 7.25 and 4.85 millions m3/year of desalinated water MW (CHP)
A preliminary report on the marine Macrobenthos and the Demersal fish fauna of the island of Filfla (Maltese Islands, Central Mediterranean)
The nature, distribution, and abundance of the main component species of the supralittoral, mediolittoral and upper infralittoral marine macrobenthic assemblages of Filfla were studied during a series of expeditions to the islet between 1990 and J 994. The demersal fish fauna was censused by direct observation. The distribution of sponges was studied along two 2m-wide belt transects laid along a gently sloping and a steep sloping bottom, respectively. In general, the same type of benthic assemblages as found on other exposed rocky coasts in the Maltese Islands occurred at Filfla. However, at Filfla, the littoral zones were compressed, and species richness and abundance in the littoral and sublittoral were generally low compared to other exposed rocky shores in the Maltese Islands. In spite of the extensive infralittoral sandy bottoms present at Filfla, no sea-grass meadows were encountered. Most of these differences are probably attributable to the high exposure, the extensive boulder shores and submarine boulder fields that surround the islet, and to bottom turbulence. Large differences in species composition and abundance of sponges were found between the two transects. Crambe crambe and Agelas oroides were the most abundant sponges on the steep bottom, while Sarcotragus spinosula was the most abundant species on the more gently sloping one. Compared to that of mainland sites, the demersal fish fauna of Filfla was impoverished in terms of both species richness and abundance.peer-reviewe
Propensity for Risk in Reproductive Strategy Affects Susceptibility to Anthropogenic Disturbance
Relative difficulty of subjects at secondary education certificate level
It is commonly held that an examination body should maintain a standard level of difficulty across different years, tiers, and subjects. Grade setting does depend, to a certain extent, on expert judgement and, not surprisingly, different studies have suggested that the same standard of difficulty is not maintained across different examination boards and subjects. In this study the level of difficulty of subjects is measured by comparing the mean general ability of candidates who obtain the same grades in the different subjects at Secondary Education Certificate (SEC), which are offered by the MATSEC Examinations Board of the University of Malta. The research method and the ensuing results are explained in detail and discussed. The outcomes show that although some differences between subjects are present, with one subject in particular being flagged as being possibly graded much easier than other subjects, differences between most subjects were not significant enough to allow a clear ordering in terms of difficulty.peer-reviewe
Resistance to thrips (Enneothrips flavens) in wild and amphidiploid Arachis species.
Thrips (Enneothrips flavens) is a pest that causes severe damage and yield losses to peanut crop if not properly controlled. The main control method currently used by farmers is biweekly application of insecticides during crop development, which, in addition to its toxicity, is very costly. Thus, new sources of resistance must be identified in order to reduce the use of insecticides and effectively manage the pest. This study aimed to evaluate the occurrence and symptoms of E. flavens infestations in 12 accessions of 10 wild species of Arachis and nine amphidiploids, as well as to compare their morphoagronomic characteristics to those of commercial cultivars. To this end, we conducted experiments during two summer seasons, using a randomized block design with four replications. We conducted evaluations of the severity of infestation, noting visual symptoms of E. flavens and morphological and reproductive characteristics of the Arachis plants. Results indicated that wild accessions V 7635 (A. vallsii), V 13250 (A. kempff-mercadoi), K 9484 (A. batizocoi), Wi 1118 (A. williamsii), V 14167 (A. duranensis) and V 13751 (A. magna) are the most promising for obtaining useful new amphidiploids. Among the amphidiploids, An 12 (A. batizocoi x A. kempff-mercadoi) 4x, An 9 (A. gregoryi x A. stenosperma) 4x, and An 8 (A. magna x A. cardenasii) 4x showed high level of resistance to E. flavens. The identified thrips resistant wild and amphidiploid Arachis species may be used in future breeding program to produce thrips resistant peanut cultivars
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