Experimental Research Data Research Articles

On the active deformations of hybrid specimens

Purpose The purpose of this study concerns numerical studies and experimental validation of the mechanical behavior of hybrid specimens. These kinds of composite specimens are made up of thin carbon and glass substrates on which some Macro Fiber Composite® (MFC) piezoelectric patches are glued. A proper design and manufacturing of the hybrid specimens as well as testing activities have been performed. The research activity has been carried out under the FutureWings project, funded by the European Commission within the 7th Framework. Design/methodology/approach The paper describes the basic assumptions made to define specimen geometries and to carry out experimental tests. Finite element (FE) results and experimental data (laser technique measurements) have been compared: it shows very good agreement for the displacements’ distribution along the specimens. Findings Within the objectives of the project, the study of passive and active deformation characteristics of the hybrid composite material has provided reference technical data and has allowed for the correct adaptation of the FE models. More in particular, using the hybrid specimens, both the bending deformations and the torsion deformations have been studied. Practical implications The deformation capability of the hybrid specimens will be used in the development of prototypical three-dimensional structures, that, through the electrical control of the MFC patches, will be able to change the curvature of their cross section or will be able to change the angle of torsion along their longitudinal axis. Originality/value The design of nonstandard specimens and the tests executed represent a novelty in the field of structures using piezoelectric actuators. The numerical and experimental data of the present research constitute a small step forward in the field of smart materials technology.

Strength research of rock cores after high-energy electron beam irradiation

The data of experimental research into mechanical properties of limestone, hornfels and sandstone cores after treatment by accelerated electrons show that the irradiation changes the strength and deformation characteristics of the tested rocks. In limestone and hornfels, uniaxial compression strength and elasticity modulus decrease, and ratio of P- and S- wave velocities changes; in sandstone tensile strength decreases, while uniaxial compression strength, P- and S-wave velocities and dynamic Young’s modulus grow. Modification of the minerals after accelerated electron irradiation opens ways of creating efficient energy-saving technologies for pre-treatment and processing of complex ores.

Publishing descriptions of non-public clinical datasets: proposed guidance for researchers, repositories, editors and funding organisations.

Sharing of experimental clinical research data usually happens between individuals or research groups rather than via public repositories, in part due to the need to protect research participant privacy. This approach to data sharing makes it difficult to connect journal articles with their underlying datasets and is often insufficient for ensuring access to data in the long term. Voluntary data sharing services such as the Yale Open Data Access (YODA) and Clinical Study Data Request (CSDR) projects have increased accessibility to clinical datasets for secondary uses while protecting patient privacy and the legitimacy of secondary analyses but these resources are generally disconnected from journal articles—where researchers typically search for reliable information to inform future research. New scholarly journal and article types dedicated to increasing accessibility of research data have emerged in recent years and, in general, journals are developing stronger links with data repositories. There is a need for increased collaboration between journals, data repositories, researchers, funders, and voluntary data sharing services to increase the visibility and reliability of clinical research. Using the journal Scientific Data as a case study, we propose and show examples of changes to the format and peer-review process for journal articles to more robustly link them to data that are only available on request. We also propose additional features for data repositories to better accommodate non-public clinical datasets, including Data Use Agreements (DUAs).

Analysis of isothermal and cooling-rate-dependent immersion freezing by a unifying stochastic ice nucleation model

Abstract. Immersion freezing is an important ice nucleation pathway involved in the formation of cirrus and mixed-phase clouds. Laboratory immersion freezing experiments are necessary to determine the range in temperature, T, and relative humidity, RH, at which ice nucleation occurs and to quantify the associated nucleation kinetics. Typically, isothermal (applying a constant temperature) and cooling-rate-dependent immersion freezing experiments are conducted. In these experiments it is usually assumed that the droplets containing ice nucleating particles (INPs) all have the same INP surface area (ISA); however, the validity of this assumption or the impact it may have on analysis and interpretation of the experimental data is rarely questioned. Descriptions of ice active sites and variability of contact angles have been successfully formulated to describe ice nucleation experimental data in previous research; however, we consider the ability of a stochastic freezing model founded on classical nucleation theory to reproduce previous results and to explain experimental uncertainties and data scatter. A stochastic immersion freezing model based on first principles of statistics is presented, which accounts for variable ISA per droplet and uses parameters including the total number of droplets, Ntot, and the heterogeneous ice nucleation rate coefficient, Jhet(T). This model is applied to address if (i) a time and ISA-dependent stochastic immersion freezing process can explain laboratory immersion freezing data for different experimental methods and (ii) the assumption that all droplets contain identical ISA is a valid conjecture with subsequent consequences for analysis and interpretation of immersion freezing. The simple stochastic model can reproduce the observed time and surface area dependence in immersion freezing experiments for a variety of methods such as: droplets on a cold-stage exposed to air or surrounded by an oil matrix, wind and acoustically levitated droplets, droplets in a continuous-flow diffusion chamber (CFDC), the Leipzig aerosol cloud interaction simulator (LACIS), and the aerosol interaction and dynamics in the atmosphere (AIDA) cloud chamber. Observed time-dependent isothermal frozen fractions exhibiting non-exponential behavior can be readily explained by this model considering varying ISA. An apparent cooling-rate dependence of Jhet is explained by assuming identical ISA in each droplet. When accounting for ISA variability, the cooling-rate dependence of ice nucleation kinetics vanishes as expected from classical nucleation theory. The model simulations allow for a quantitative experimental uncertainty analysis for parameters Ntot, T, RH, and the ISA variability. The implications of our results for experimental analysis and interpretation of the immersion freezing process are discussed.

Estimating More Precise Treatment Effects in Natural and Actual Experiments

The importance of using natural experiments and experimental data in economic research has long been recognized. Yet, it is only in recent years that these approaches have become an integral part of the economist's analytical toolbox, thanks to the efforts of Meyer, Card, Peters, Krueger, Gruber, and others. This use has shed new light on a variety of public policy issues and has already caused a major challenge to some tightly held beliefs in economics, most vividly illustrated by the finding of a positive effect of a minimum wage increase on the employment of low-wage workers. Although currently in vogue in economic research, the analysis of experimental data and natural experiments could be substantially strengthened. This paper discusses how analysts could increase the precision with which they measure treatment effects. An underlying theme is how best to measure the effect of a treatment on a variable, as opposed to explaining a level or change in a variable.

Analysis of stress-strain state of a steel rope wound on a drum using finite element method

In the article the analysis of the stress-strain state of a steel rope wound on a drum usingfinite element method.The analysis of 26 literature of foreign and domestic researchers, whose work is devoted tothe study of ropes, the stress-strain state, finite element method, modeling and research inSolidWorks and ANSYS software fields.In the program SolidWorks 2015 constructed geometric model of the rope drum and, as aprototype of which was used the rope drum and applied in experimental studies, in accordance withtheir geometric dimensions and physical properties of the materials from which they are made.In the program ANSYS 17 carried out a study of three-dimensional models ¼ rope coil in bendingon a segment of the drum shell. As well as the study of three-dimensional model with 14 coiling coils ofrope on the drum. In the study of the smallest models have been applied in the construction of elementaryfigures staked grid. An convergence graph of the solution in the calculation model.It made a graphical comparison of the results obtained from the calculation formulas anddata of experimental research data obtained by finite element method.

New Approach in Investigating the Role of Interaction between an Organism and Physical Factors in Complex Patient Therapy

This work is dedicated to the new approach in applying physical factors in complex patient therapy. Based on experimental research data the author believes it is necessary to reconsider technical characteristics and exposition of physiotherapeutic factor influencing on the organism taking into account nosological form of disease and individual patient’s specifics. In this regard the author developed new tasks of the clinical physiotherapy and suggested seven principles of new classification of physical factors in complex patient therapy. On the basis of the research the author provided new concepts in medicine: 1) human organism as “biological scanning tunneling microscope”; 2) human as a part of “Nature” corresponds to universe general law: “singularity and indivisibility of time, matter and form”, as well as the forces of their interaction under constant endless motion.

On the Transformation of Economic Analysis of Tort Law

The Research Handbook on the Economic of Torts (Edward Elgar, 2013), edited by Jennifer Arlen, contains a very impressive collection of contributions written by leading tort scholars. The major theme that runs through the Handbook's diversified chapters is that the economic analysis of tort law has developed, as it should have, from ideal and generalized models into more realistic, informed and context-related analysis. The traditional, canonical, models were ideal and generalized in the sense that they tended to focus on two parties (victim and injurer), in a world of perfect information, of optimal courts, of no litigation costs and of no insurance. They assumed that the threat of tort liability can induce due (efficient) care by both (solvent) injurers and victims, and that same economic analysis models are applicable to different types of accident and harms. More recent and more mature economic analysis, it is demonstrated, has acknowledged, and has been adjusted to, the realities of imperfect and asymmetrical information, courts' errors, significant litigation costs, the complexity of multi-party litigation and the limits of tort law as an efficient deterrent given cognitive biases, limited ability to control inadvertence and insolvency. Economic analysis according to this theme has developed to be much more sensitive to context, to insurance, to institutional liability, to the importance of experimental research and empirical data, and to the alternatives to tort liability. Other traits of the mature economic analysis are recognition, even by its proponents, that actual tort law is sometimes inefficient, and that different economic models have to be synthesized. This review has two major parts. The first part illustrates, by comparing different topics and contributions, how important factors that were previously disregarded or understated are integrated into present economic analysis. These factors are: imperfect and asymmetrical information, adjustments of the deterrent effect of tort liability, institutional liability, context-based analysis, and experimental legal studies and their implications on tort reforms and tort theory. The second part comments on and criticizes the Chapters on medical malpractice, causation, fault and insurance, challenging some of the claims and proposals made there. It concludes with two reflections on the economic analysis of tort law.

Óleo vegetal – um substituto do óleo mineral para uso em transformadores: revisão do estado da arte

The importance of the role played by insulating liquids in the good performance of transformers, associated to the increase of environmental concerns, in case of fire, explosion, or possible oil leaks, explains the increased interest in the research about the use of vegetable oils (an earth friendly and fire resistant product), in electrical industry, as substitute of minerals oils. This paper presents the comparison of vegetable oils with mineral oils, in terms of their properties including their influence in the degradation of paper immersed in those oils. It is also presented here, the main advantages of vegetable oils, and the most important improvements that have been recently introduced in such oils, based mainly on experimental research data from laboratory. In spite of the fact that some hundreds of transformers filled with vegetable oils have been working worldwide with good performance, these oils have, until now, a limited use. So, there is a high potential increase for their application, as substitutes of mineral oils, playing the role of electrical insulating, coolant and arc quenching fluid, in electrical transformers, what demands a better knowledge about these fluids. So, the clarification of some doubts, in this field, is one of the main goals of this paper.

Research Data of Turbine Nozzles of 5-9 Degree Outlet Angles

The article presents experimental data of microturbines nozzle boxes research. It describes mathematical models of nozzle outlet gas angle. Research results are analyzed and recommendations on design of nozzle boxes with small constructive outlet gas angle are given.

Ellipsometry method application in optics of inhomogeneous media

Physico-mathematical methods of modeling and measurements of polarization optical characteristics of “inhomogeneous surface layer – inhomogeneous medium” reflective system have been improved based on generalization of the polarized light reflection theory in the Born approximation from inhomogeneous media interface. Theoretical and experimental justification for simultaneous application of multi-angular and scanning ellipsometry methods is given for gradient optics elements in inhomogeneous layer presence on the surface of the optical detail. The measurement of the main ellipsometric parameters – linear reduced polarization azimuth Ψand phase difference Δbetween mutually orthogonal p– and s– components of a reflected polarized light beam – was carried out on a dual-channel installation, in which the scheme of measurements of polarization parameters Ψand Δby balanced (null) ellipsometry method is used in the first channel; the photometric scheme of measurements of parameters Ψand Δby Fourier method of output detection is used in the second channel. Such separation of channels gives the possibility for measuring of polarization parameters of reflected light beam separately and, thereby, improving the accuracy of ellipsometric measurements in relation to observable physical quantity of measurements object. The values of refractive index n(r) and absorption index k(r) were calculated by axial section of selfoc on the basis of measurements of polarization parameters Ψand Δwith angle of incidence of the light beam φ=45о within the limits of scanning ellipsometry method and a model of geometrically flat interface of homogeneous media. Empirical data indicated the model incorrectness of the geometrically flat interface for polarization measurements of refractive index distributionn(r) and absorption index k(r) in gradient optical engineering elements. For the reflective system “inhomogeneous surface layer – inhomogeneous medium” the refractive index n(r) change by axial section of an element r is proportional to phase difference Δ(r) between mutually orthogonal components of a reflected light beam. At the same time the linear reduced polarization azimuth Ψ(r) in the section gradient optical element varies slightly. The main proportions for calculation of refractive index nсand thickness dсof superficial layer in each local point r of selfoc are adduced on the basis of the ellipsometry equation, obtained within the framework of the polarized light reflection Born theory. Empirical data of experimental researches make it possible to give quantitative assessment of surface processing quality for optical engineering elements. Elaborated ellipsometric techniques are recommended in technological production of optical base assemblies with gradient and fiber optics elements.

Experimental research on a THGEM-based thermal neutron detector**Supported by National Natural Science Foundation of China (11127508, 11175199), NPL, CAEP (2013DB06) and State Key Laboratory of particle Detection and Electronics (H9294206TD)

A new thermal neutron detector with a domestically produced THGEM (Thick Gas Electron Multiplier) was developed as an alternative to 3He to meet the needs of the next generation of neutron facilities. One type of Au-coated THGEM was designed specifically for neutron detection. A detector prototype has been developed and the preliminary experimental tests are presented, including the performance of the Au-coated THGEM working in Ar/CO2 gas mixtures and the neutron imaging test with 252Cf source, which can provide the reference for experimental data for research in the future.

Characteristics and Calculation of Cavitation Mixers

It is shown that one of the most efficient ways to obtain emulsion is cavitation treatment of the mixed stream in the jet boundary layer. The authors offer a model for calculating the operational process in the hydrodynamic mixer with multiple-jet nozzle as agitator of cavitation, based on hydrodynamic equations and data of experimental research on jet pumps. There has been considered and analyzed the characteristic of the cavitation mixer, which shows how relative loss of total stream pressure depends on relative nozzle square, and hydraulic resistance coefficient of flow-part elements. It is shown that gradual reduction of hydraulic resistance coefficient allows to decrease considerably the loss of total stream pressure. Besides, there exists the range of optimal relative square values where losses of total pressure are minimized. If the elements of the mixer flow-part are made hydraulically proper then the optimal values of the nozzle relative square are 0,66…0,76, whereas minimum losses of relative pressure don’t exceed 0,22.

Simultaneous Quantitative Determination of Nine Bufadienolides in Traditional Chinese Medicinal Toad Skin from Different Regions of China by High-Performance Liquid Chromatography–Photodiode Array Detection

Toad skin is a traditional Chinese medicine for the treatment of various tumors. The major active components in toad skin are bufadienolides. In this paper, a simple, accurate and reliable method for the simultaneous separation and determination of nine active components (gamabufotalin, arenobufagin, telocinobufagin, desacetylcinobufotalin, bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogeni) in toad skin was developed using High-Performance Liquid Chromatography (HPLC) coupled with Photodiode Array Detection (PDA) detection. The chromatographic separation was performed on a SinoChrom ODS-BP C18 column with gradient elution using acetonitrile and 0.1% acetic acid-0.5% potassium dihydrogen phosphate aqueous solution at a flow rate of 0.8 mL min-1. All compounds showed good linearity in a wide concentration range with the values of r2 higher than 0.9994, and their limits of detection were at the range of 0.06-0.10 μg mL-1. The separation and identification of the nine bufadienolides in this paper may provide important experimental data for further research and application of toad skin.

Hydraulic Bipedal Robots Locomotion Mathematical Modeling

The paper delivered describes a new approach into kinematics and dynamics of the robots with a tree-like kinematic structure based on the elements of graph theory. Block-matrix equation for robot's movement within generalized coordinates is valid for different tree-like kinematic structures with no change in tracing. It permits to develop generalized software for the whole class of tree-like kinematic structure. Some of the modelling details in hydraulic actuator of bipedal robot are submitted. Experimental research data of robot's walking based on mathematical modelling are compared to those of a pilot model.

Contemporary perspective on endogenous myocardial regeneration.

Considering the complex nature of the adult heart, it is no wonder that innate regenerative processes, while maintaining adequate cardiac function, fall short in myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well as restricted regeneration. In this review, the background as well as potential mechanisms of endogenous myocardial regeneration are summarized. We present and analyze the available evidence in three subsequent steps. First, we examine the experimental research data that provide insights into the mechanisms and origins of the replicating cardiac myocytes, including cell populations referred to as cardiac progenitor cells (i.e., c-kit+ cells). Second, we describe the role of clinical settings such as acute or chronic myocardial ischemia, as initiators of pathways of endogenous myocardial regeneration. Third, the hitherto conducted clinical studies that examined different approaches of initiating endogenous myocardial regeneration in failing human hearts are analyzed. In conclusion, we present the evidence in support of the notion that regaining cardiac function beyond cellular replacement of dysfunctional myocardium via initiation of innate regenerative pathways could create a new perspective and a paradigm change in heart failure therapeutics. Reinitiating cardiac morphogenesis by reintroducing developmental pathways in the adult failing heart might provide a feasible way of tissue regeneration. Based on our hypothesis "embryonic recall", we present first supporting evidence on regenerative impulses in the myocardium, as induced by developmental processes.

Experimental Research Data Quality in Materials Science

In materials sciences, a large amount of research data is generated through a broad spectrum of different experiments. As of today, experimental research data including meta-data in materials science is often stored decentralized by the researcher(s) conducting the experiments without generally accepted standards on what and how to store data. The conducted research and experiments often involve a considerable investment from public funding agencies that desire the results to be made available in order to increase their impact. In order to achieve the goal of citable and (openly) accessible materials science experimental research data in the future, not only an adequate infrastructure needs to be established but the question of how to measure the quality of the experimental research data also to be addressed. In this publication, the authors identify requirements and challenges towards a systematic methodology to measure experimental research data quality prior to publication and derive different approaches on that basis. These methods are critically discussed and assessed by their contribution and limitations towards the set goals. Concluding, a combination of selected methods is presented as a systematic, functional and practical quality measurement and assurance approach for experimental research data in materials science with the goal of supporting the accessibility and dissemination of existing data sets.

Development of Testing Machine for Measuring Unsteady State EHL Film under Heavy Load

In order to study elastohydrodynamic lubrication characteristics of cylindrical roller under heavy load and unsteady state, a testing machine is designed for measuring line contact film thickness and shape according to optical interference principle. The experimental apparatus is mainly made of glass block reciprocating motion systems, ball or roller rolling rotation system, loading system, speed control systems, lighting systems and image acquisition system. Moving parts is formed by the slider-crank mechanism. Specimen is accompanied by a pair of floating trial roller bearing. Specimen load is applied by leverage. The entrainment velocity of roller is approximate sinusoidal variation during a cycle. Experiment interference image is satisfactory, can provide reliable experimental data for future research.

Seismic Response Analysis on the Repaired HSC Structure after Fire

With the extensive use of HSC in the tall building and super high-rise building, the harm of HSC subjected to fire has also been increasing. For the concrete structure in the seismic region after fire, its seismic performance after repair directly relates to the structure safety under the action of possible earthquake in the future. Based on the experimental data in the preliminary research, seismic response analysis on the repaired HSC structure after fire was made according to the principle of uniform section. The results indicate that the seismic performance of HSC frame structure repaired by the principle of uniform section can be restored to the level before fire. But we should pay more attention to the interlaminar maximum displacement of fire storey, which should be partly strengthened when necessary.

RESEARCH OF PARAMETERS PRISMATIC PLACEHOLDER WITH THE STATIC LOADING

The work is devoted to experimental research of parameters of prismatic aggregate at static loading. The data of experimental researches allow to use them in the design of three-layer structures in space, aviation techniques, as well as in construction and machinery that is of interest for technical workers and designers.