The Impact of Worker Effort on Public Sentiment Towards Temporary Migrants

Temporary and circular migration programs have been devised by many destination countries and supported by the European Commission as a policy to reduce welfare and social costs of immigration in destination countries. In this paper we present an additional reason for proposing temporary migration policies based on the characteristics of the foreign labor-effort supply. The level of effort exerted by migrants, which decreases over their duration in the host country, positively affects production, real wages and capital owners' profits. We show that the acceptance of job offers by migrants result in the displacement in employment of national workers. However it increases the workers‟ exertion, decreases prices and thus can counter anti-immigrant voter sentiment. Therefore, the favorable sentiment of the capital owners and the local population towards migrants may rise when temporary migration policies are adopted.Migration, Exertion of effort, Contracted Temporary Migration

The Impact of Worker Effort on Public Sentiment Towards Temporary Migrants

Temporary and circular migration programs have been devised by many destination countries and supported by the European Commission as a policy to reduce welfare and social costs of immigration in destination countries. In this paper we present an additional reason for proposing temporary migration policies based on the characteristics of the foreign labor-effort supply. The level of effort exerted by migrants, which decreases over their duration in the host country, positively affects production, real wages and capital owners' profits. We show that the acceptance of job offers by migrants result in the displacement in employment of national workers. However it increases the workers' exertion, decreases prices and thus can counter anti-immigrant voter sentiment. Therefore, the favorable sentiment of the capital owners and the local population towards migrants may rise when temporary migration policies are adopted.migration, exertion of effort, contracted temporary migration

The Impact of Worker Effort on Public Sentiment Towards Temporary Migrants

Temporary and circular migration programs have been devised by many destination countries and supported by the European Commission as a policy to reduce welfare and social costs of immigration in destination countries. In this paper we present an additional reason for proposing temporary migration policies based on the characteristics of the foreign labor-effort supply. The level of effort exerted by migrants, which decreases over their duration in the host country, positively affects production, real wages and capital owners\' profits. We show that the acceptance of job offers by migrants result in the displacement in employment of national workers. However it increases the workers\' exertion, decreases prices and thus can counter anti-immigrant voter sentiment. Therefore, the favorable sentiment of the capital owners and the local population towards migrants may rise when temporary migration policies are adopted.Migration, Exertion of effort, Contracted Temporary Migration

Memecry: tracing the repetition-with-variation of formulas on 4chan/pol

In this article we propose a new theoretical framework to conceptualise Internet memes and to trace their temporal variation on 4chan/pol/. We draw from literature on primary and secondary orality to conceptualise the repetition-with-variation of Internet memes as a form of memecry, which we argue is specifically pertinent to the collectivity of online subcultures. We operationalise its study through formulas: mnemonic phrases that encapsulate important elements of oral cultures, which have arguably regained prominence in ephemeral and fast-paced online environments. While Internet memes have often been studied as single images or words, formulas provide a more complex unit for tracing variation and not only circulation. We offer a quali-quantitative protocol to investigate memecry and visualise the spread and variability of 65 prominent formulas on 4chan/pol/, a far-right space known for its reliance on memes. By discussing several cases, we demonstrate how 4chan’s collective identity indeed features typical of secondary oral cultures, while revealing how the memecry of its formulas is entwined with reactionary sentiments and a subcultural struggle for distinction

Hardware-In-The-Loop Assessment of Robust Fuzzy Control Solutions for Hydroelectric and Wind Turbine Models

The interest towards renewable energy resources is increasing, and in particular it concerns wind and hydro powers, where the key point regards their efficient conversion into electric energy. To this end, control techniques can be used to meet this purpose, especially the ones relying on fuzzy models, due to their capabilities to manage nonlinear dynamic processes working in different conditions, and affected by faults, measurement errors, uncertainty and disturbances. The design methods addressed in this paper were already developed and validated for wind turbine plants, and important results can be achieved from their appropriate design and application to hydroelectric plants. This is the key issue of the paper, which recalls some considerations on the proposed solutions, as well as their validation to these energy conversion systems. Note that works available in the related literature that consider both wind and hydraulic energy conversion systems investigate a limited number of common issues, thus leading to little exchange opportunities and reduced common research aspects. Another important point addressed in the paper is that the proposed control design solutions are able to take into account the different working conditions of these power plants. Moreover, faults, uncertainty, disturbance and model reality mismatch effects are also considered when analyzing the reliability and robustness features of the derived control schemes. To this end, proper hardware in the loop tools are considered to verify and validate the developed control schemes in more realistic environments. Copyright (C) 2022 The Authors

Comparison of different approaches to predict the performance of pumps as turbines (PATs)

This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs). The considered approaches are four, i.e., one physics-based simulation model ("white box" model), two "gray box" models, which integrate theory on turbomachines with specific data correlations, and one "black box" model. More in detail, the modeling approaches are: (1) a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2) a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3) the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4) an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53-5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed.This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs). The considered approaches are four, i.e., one physics-based simulation model ("white box" model), two "gray box" models, which integrate theory on turbomachines with specific data correlations, and one "black box" model. More in detail, the modeling approaches are: (1) a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2) a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3) the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4) an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53-5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed

Energy production by means of pumps as turbines in water distribution networks

This paper deals with the estimation of the energy production by means of pumps used as turbines to exploit residual hydraulic energy, as in the case of available head and flow rate in water distribution networks. To this aim, four pumps with different characteristics are investigated to estimate the producible yearly electric energy. The performance curves of Pumps As Turbines (PATs), which relate head, power, and efficiency to the volume flow rate over the entire PAT operation range, were derived by using published experimental data. The four considered water distribution networks, for which experimental data taken during one year were available, are characterized by significantly different hydraulic features (average flow rate in the range 10-116 L/s; average pressure reduction in the range 12-53 m). Therefore, energy production accounts for actual flow rate and head variability over the year. The conversion efficiency is also estimated, for both the whole water distribution network and the PAT alone.This paper deals with the estimation of the energy production by means of pumps used as turbines to exploit residual hydraulic energy, as in the case of available head and flow rate in water distribution networks. To this aim, four pumps with different characteristics are investigated to estimate the producible yearly electric energy. The performance curves of Pumps As Turbines (PATs), which relate head, power, and efficiency to the volume flow rate over the entire PAT operation range, were derived by using published experimental data. The four considered water distribution networks, for which experimental data taken during one year were available, are characterized by significantly different hydraulic features (average flow rate in the range 10-116 L/s; average pressure reduction in the range 12-53 m). Therefore, energy production accounts for actual flow rate and head variability over the year. The conversion efficiency is also estimated, for both the whole water distribution network and the PAT alone

Comparison of different approaches to predict the performance of pumps as turbines (PATs)

This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs). The considered approaches are four, i.e., one physics-based simulation model ("white box" model), two "gray box" models, which integrate theory on turbomachines with specific data correlations, and one "black box" model. More in detail, the modeling approaches are: (1) a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2) a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3) the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4) an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53-5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed.This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs). The considered approaches are four, i.e., one physics-based simulation model ("white box" model), two "gray box" models, which integrate theory on turbomachines with specific data correlations, and one "black box" model. More in detail, the modeling approaches are: (1) a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2) a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3) the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4) an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53-5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed