Design of Optimal Real Time Emulators for Steam and Wind Turbines for Avoiding Risky Severe Conditions

Modern energy infrastructures may face critical impacts on distributed generation and microgrids in presence of renewable and conventional energy sources. Fast restorations for these networks through proposing convenient proactive protection systems become mandatory for securing energy particularly after severe faults. This paper deals with presenting a descriptive modelling and comprehensive analysis of both steam and wind turbines using optimal real time emulators with unique testbench. Based on the dynamics of each turbine, both emulators are performed using 4kW, 180V, 1500r.p.m separately exited DC motor coupled to 2kW, 380V, 50Hz, 1500r.p.m three-phase synchronous generator. For real-time interface implementation, the mathematical models of steam and wind turbines are realized using LabVIEWTM software. The characterization and verification of both emulated steam and wind turbines are examined at different normal operating conditions in terms of steam valve position and wind speed, respectively. To regulate the current for both systems despite their diverse dynamics, a simple industrial proportional-integral (PI) controller is considered. Unlike other artificial intelligence-based controllers, the offline-controller gains are scheduled using genetic algorithm (GA) via MatlabTM software to ensure the due fast response to cope with unexpected faults. The experimental validity of both emulators is tested at the most severe abnormal operating conditions. The three-phase short circuit is considered at the generator terminals with different fault periods until reaching out-of-step conditions. From numerical analysis and experimental results, the characterization of both emulated steam and wind turbines explicitly mimics their real large-scale turbines in normal conditions. The emulators’ fast responses using the proposed GA-PI control approach are verified. Besides, the experimental dynamic behavior convergence and interoperability between the emulated and real systems for both steam and wind turbines are validated under severe conditions. The practical results confirm the fast-nature performance of the GA in avoid risky instability conditions.

Experimental practices and objectivity in the social sciences: re-embedding construct validity in the internal–external validity distinction

The experimental revolution in the social sciences is one of the most significant methodological shifts undergone by the field since the ‘quantitative revolution’ in the nineteenth century. One of the often valued features of social science experimentation is precisely the fact that there are (alleged) clear methodological rules regarding hypothesis testing that come from the methods of the natural sciences and from the methodology of RCTs in the biomedical sciences, and that allow for the adjudication among contentious causal claims. We examine critically this claim and argue that some current understandings of the practices that surround social science experimentation overestimate the degree to which experiments can actually fulfil this role as “objective” adjudicators, by neglecting the importance of shared background knowledge or assumptions and of consensus regarding the validity of the constructs involved in an experiment. We take issue with the way the distinction between internal and external validity is often used to comment on the inferential import of experiments, used both among practitioners and among philosophers of science. We describe the ways in which the more common (dichotomous) use of the internal/external distinction differs from Cook and Campbell’s original methodological project, in which construct validity and the four-fold validity typology were all important in assessing the inferential import of experiments. We argue that the current uses of the labels internal and external, as applied to experimental validity, help to encroach a simplistic view on the inferential import of experiments that, in turn, misrepresents their capacity to provide objective knowledge about the causal relations between variables.

Numerical transient responses of cut-out borne composite panel and experimental validity

The effect of cut-out parameters (shapes: square and circular; position: concentric/eccentric) on the dynamic deflection values of the curved/flat layered composite panel are verified experimentally with the higher-order finite element solutions first-time. The solutions are obtained using the linear finite element model in the framework of cubic-order displacement filed functions. The necessity of higher-order kinematic model is verified by comparing the experimental transient data by conducting the different test to show the accuracy of the finite element solution. Moreover, the theoretical finite element solutions are obtained using the own experimental elastic property data for the comparison (numerical and experimental) purpose. Finally, the critical behaviour of the proposed numerical model for the dynamic analysis of damaged composite structure is examined by solving different types of example by varying the design constraint parameter including the cut-out factors (shape, size, location and eccentricity). The inclusiveness of each parameter on the time-dependent deflections is expressed in details from the various example including the comparison.

Methods to evaluate the twin formation energy: comparative studies of the atomic simulations and in-situ TEM tensile tests

Deformation twinning, one of the major deformation modes in a crystalline material, has typically been analyzed using generalized planar fault energy (GPFE) curves. Despite the significance of these curves in understanding the twin nucleation and its effect on the mechanical properties of crystals, their experimental validity is lacking. In this comparative study based on the first-principles calculation, molecular dynamics simulation, and quantitative in-situ tensile testing of Al nanowires inside a transmission electron microscopy system, we present both a theoretical and an experimental approach that enable the measurement of a part of the twin formation energy of the perfect Al crystal. The proposed experimental method is also regarded as an indirect but quantitative means for validating the GPFE theory.

Methods to evaluate the twin formation energy: comparative studies of the atomic simulations and in-situ TEM tensile tests

Deformation twinning, one of the major deformation modes in a crystalline material, has typically been analyzed using generalized planar fault energy (GPFE) curves. Despite the significance of these curves in understanding the twin nucleation and its effect on the mechanical properties of crystals, their experimental validity is lacking. In this comparative study based on the first-principles calculation, molecular dynamics simulation, and quantitative in-situ tensile testing of Al nanowires inside a transmission electron microscopy system, we present both a theoretical and an experimental approach that enable the measurement of a part of the twin formation energy of the perfect Al crystal. The proposed experimental method is also regarded as an indirect but quantitative means for validating the GPFE theory.

Medical English vs. Literary English: A Contrastive Analysis

The present study tends to determine what kinds of linguistic features and styles distinguish Medical English from literary English. Corpus analyses of both the varieties were taken into account. Ten scientific research papers drawn from each genre were linguistically analyzed. It was found that the kind of English used in Medical sciences is marked with accuracy, precision and hybridized language mixed with Latin and French. Medical scientists reveal proven facts and findings whereas literary writers just illustrate their creative thoughts with illusions, allusions and figurative language. Literary language contains non universal features and represents the artist's inner self which doesn't at all need extraneous and empirical evidence to put forth his spontaneous overflow of powerful feeling. On the contrary, medical language needs empirical experience and experimental validity. The investigation also suggests that medical English contains more passivation, nominalization, lexical density and foregrounding which are found far less in literary English. Moreover, medical scientists unlike literary artists , are adhered to a clearly defined IMRAD structure which contains Introduction, Methods, Result and Discussion sections.

SILVER RECOVERY FROM END-OF-LIFE PHOTOVOLTAIC PANELS

The growth of the photovoltaic sector has stood out among renewable sources of energy, due to technological innovations that have brought about cost reductions. Thus, this paper aimed to analyze the technical feasibility of silver recovery from photovoltaic cells using acid leaching, followed by an evaluation of the chemical and electrochemical precipitation processes to analyze their efficiencies. As a primary objective of this work, the gravimetric composition and the metal concentration (Ag, Al, Pb, Cu, and Fe) in the photovoltaic cells were first determined, developing the basis for future research on photovoltaic panels recycling Subsequently, the influence of HNO3 concentration (1-10 mol/L), temperature (25-60ºC), and reaction time were evaluated. A new research application used a statistical tool, the Central Composite Rotational Design (CCRD), as well as samples of different brands and models of photovoltaic panels, in order to ensure the experimental validity. As a highlight, the analysis of the composition of the photovoltaic cells, applying the HNO2CO3, as well as electroprecipitation, made it possible to extract more than 99% of silver in solution, being a primary novelty of this study. Therefore, the studied pathway allowed for the recovery of 99.98% of the silver present in the photovoltaic cells.

Addressing selective reporting of experiments – the case for predefined exclusion criteria

Articles describing experimental data in the life sciences are meant to tell a clear story to the reader. This means that not every experimental attempt ends up published, as failed experiments and uninformative data are typically filtered out by researchers. Freedom to exclude data from an article, however, can lead to reporting bias when exclusion decisions are made after results are in. We discuss how to balance clarity and thoroughness in biomedical research reporting, and suggest that predefined criteria for experimental validity might help in solving this conflict.