Pressure Drops and Energy Consumption Model of Low-Scale Closed Circuit Cooling Towers

Heat transfer models of closed-circuit cooling towers are available in the literature. Using these models, traditional parametric studies show how the inlet conditions of the streams influence the cooling capacity. This type of analysis could yield to suboptimal operation of the cooling tower since optimal heat and mass transfer processes do not necessarily imply an energy efficient cooling device. The optimal design of closed-circuit cooling towers should include any evaluation of pressure loses associated with the three streams involved. Air-water biphasic pressure drop across tube bundles in such devices was not sufficiently investigated in literature. The proposed literature correlations depend on geometry parameters, and these parameters are not known. In this work, an experimental device has been designed and constructed to study pressure drops, and an energy consumption model has been developed. The pressure drop was successfully calculated modifying a general correlation proposed for two phase flow across tube bundles. The energy model results show that the optimum was obtained where the intube water Reynolds number is near the transition region, and at air velocities near 1 m/s

Spatial productivity spillovers across Spanish municipalities

Whilst a great deal of e¤ort has been dedicated to identification of agglomeration effects on labour productivity, the measurement of spatial productivity spillovers is a question that has been addressed only occasionally along the New Economic Geography literature. We estimate agglomeration effects, nonetheless conditioned to the possible existence of spatial productivity spillovers across Spanish municipalities in year 2001. To this respect, we find that agglomeration effects are in the same order of magnitude than thoseencountered when measured in the standard way. Further, these agglomeration efects coexist with very strong spatial productivity spillovers in a close neighbourhood of 10 km. Finally, these spatial e¤ects are shown to quickly diminish as distance increases.IV estimation, elevation, spatial externalities, productivity, neighbourhood, Spain

The European Map of Job Flows

The European Map of Job Flows (EMJF) is a term used to denote a dataset of meso- and macro-level variables describing different aspect of labour mobility within national labour markets in Europe. In this paper, EMJF is centred on the notion of job “flows”, namely the changes in the level of employment at different breakdowns and levels of aggregation. EMJF is very rich in information content due to the wide variety of possible breakdown of the data and in this sense it is a “map” mostly in the virtual sense, namely, that it is not possible to visualise in the form of geographic maps all the wealth of available information. In terms of its value as a research product and tool, EMJF is mostly an intermediate product in the sense that it is a convenient means to organise the relevant information, which could subsequently be used for different analytical and research purposes. It provides both for cross-sections/snapshots of job flows at different point in time but also it allows their assessment and analysis over longer periods of time. In this sense, EMJF can be widely used for various types of labour-market analysis and research. EMJF’s visual components can also be a convenient tool for policy makers dealing with labour market policies at different level (regional, national or supra-national) in the decision-making process. Here we present a Compilation of a EMJF on the basis of firm-level data In this sense the job flows are built up on the basis of firm-level data for individual countries, following a common methodology. We adopt an approach of establishing such a EMJF on the basis of the AMADEUS dataset developed by the consultancy Bureau van Dijk. The dataset in its most extended version contains balance sheet data and ownership data for almost 14 million firms from 43 different European countries (September 2009 update). For many EU countries the dataset has in principle access to the entire universe of firms which have to report a balance sheet. In terms of countries, the geographic coverage of AMADEUS encompasses information for all the 27 members of the European Union (albeit with different qualities in terms of national coverage) as well as other 16 European countries that complete the geographical and political definition of the continent. Another interesting feature of the database is given by the detailed definition of a firm's location, with data available on the region (NUTS2) and the city in which the firm operates. This project deliverable presents the main results from the final stage of MICRO-DYN work on the EMJF. It discusses the approach to building the EMJF on the basis of AMADEUS data and illustrates the analytical potential of the EMJF as a research tool with a range of Europe-wide analytical exercises. Probably the most important outcome of this research effort is the demonstrated capability to perform meta-analysis at the European level of important labour market characteristics on the basis of firm-level data.job flows, europe, labor market, microdata

Forest Ecosystem Services: An Analysis of Worldwide Research

The relevance of forests to sustain human well-being and the serious threats they face have led to a notable increase of research works on forest ecosystem services during the last few years. This paper analyses the worldwide research dynamics on forest ecosystem services in the period from 1998 to 2017. A bibliometric analysis of 4284 articles was conducted. The results showed that the number of published research articles has especially increased during the last five years. In total, 68.63% of the articles were published in this period. This research line experiences a growing trend superior to the general publishing trend on forest research. In spite of this increase, its relative significance within the forest research is still limited. The most productive subject areas corresponded to Environmental Science, Agricultural and Biological Sciences and Social Sciences Economic topics are understudied. The scientific production is published in a wide range of journals. The three first publishing countries are United States, China and the United Kingdom. The most productive authors are attached to diverse research centres and their contributions are relatively recent. A high level of international cooperation has been observed between countries, institutions and authors. The findings of this study are useful for researchers since they give them an overview of the worldwide research trends on forest ecosystem services

The Sustainable Management of Metals: An Analysis of Global Research

The objective of this study was to analyze research trends in the field of sustainable management of metals on a global level between 1993 and 2017. To do so, a bibliometric analysis was carried out on a total of 6967 articles. The results revealed the growing interest in this research field, particularly over the last five year-period during which 63% of all articles were published. The three journals in which most articles had been published were the Journal of Cleaner Production, ACS Sustainable Chemistry and Engineering, and Chemsuschem. The countries that published the most articles were China, the United States, India, Germany, and the United Kingdom. A sizeable network of collaboration has been established between countries for the joint publication of studies. The main lines of research have been focused on metal decontamination in water and soil, waste management oriented towards reuse and recycling, and the innovation of processes for cleaner and more efficient production. The results revealed the need for comprehensive studies that integrate different disciplines within the same analytical framework, and to promote research that contributes to the different dimensions of sustainability (environmental, economic, and social)

Phoretic relationship between the myceliophagous mite Microdispus lambi (Acari: Microdispidae) and mushroom flies in Spanish crops

We studied the role played by the phorid Megaselia halterata (Wood) and the sciarid Lycoriella auripila (Winnertz) in the phoretic dispersion of the myceliophagous mite Microdispus lambi (Acari: Pygmephoridae). Twenty‐four crops were monitored during 18 months in commercial mushroom farms in Castilla‐La Mancha (Spain). Adults of both species were collected weekly and the mites they carried were counted and identified. Both phorids (19.6%) and sciarids (4.4%) carried the mite M. lambi. The calculated load of each was 3.4 M. lambi mites per phorid and 1.9 per sciarid. The same percentage of male and female phorid was used as vector, but the load was slightly higher for females (1.86 mites per female compared with1.48 mites per male). A mean of 7.2% of the phorids examined in winter were vectors of M. lambi, while in spring and autumn of the first year the average was more than 22%. The mean load did not vary significantly between seasons. Inside the mushroom farms, less than 10% of a small initial population of phorids carried mites (less than two mites per phorid). As the cycle progressed, more than 35% of a larger population of emerging flies did so (average 3.5 mites per phorid vector). At the end of the growth cycle, the flies may fly off to colonise nearby farms, favouring the propagation of M. lambi from infested to uninfested crops. Megaselia halterata is the principal vector of M. lambi in the mushroom farms of Castilla‐La Mancha due to their high numbers, the high percentage carrying mites and the number of M. lambi they carry.info:eu-repo/semantics/acceptedVersio