A Mössbauer study of the oxidation of Fe-Ni alloys at 535 and 635°C

Fe⁵⁷ transmission Mössbauer spectroscopy, supported by metallography, SEM and X-ray diffraction analysis, has been employed to study the oxidation of Fe-Ni alloys at 535 and 635° C in 1 atm. of air. With increasing Ni content of the alloy, the composition of the scale changed and the oxidation rate decreased. For an alloy containing 0.9% Ni, the oxide scale produced at 535° C was Fe₃O₄ covered by a thin outer layer of-Fe₂O₃, while at 635° C FeO was additionally present as a major phase. The scale formed on a 10% Ni alloy at both 535 and 635° C was similar to that observed for the 0.9% Ni alloy oxidized at 535° C (i.e. of Fe₃O₄ and-Fe₂O₃), although the-Fe₂O₃ layer tended to be relatively thicker. For a 49% Ni alloy, the scale at both 535 and 635° C comprised an inner layer of Ni _x Fe_3–x O₄ (withx0.5, on average) and an outer layer of-Fe₂O₃, of similar thickness. Finally, on an 83% Ni alloy oxidized at 635° C, the scale consisted of roughly equally thick layers of NiO (next to the metal) and NiFe₂O₄, and a thin outer covering of-Fe₂O₃. The decrease in oxidation rate with increasing Ni content of the alloy is discussed briefly in relation to the changing composition of the scale and diffusion in the alloy.     

New insights into the hardening and pitting corrosion mechanisms of thermally aged duplex stainless steel at 475℃:A comparative study between 2205 and 2101 steels

In this study,the relationship between spinodal decomposition and the formation of Ni-rich clusters and G-phase in the ferrite on hardening and pitting corrosio...     

Does digital imaging decrease patient dose? A pilot study and review of the literature

The potential for decreasing patient dose is one of the main arguments for the justification of the cost of digital imaging equipment. However, the literature review with respect to patient doses using digital imaging modalities, presents conflicting results. During this study, patients' entrance surface doses were measured for three simple radiographic examinations, in European centres equipped with a computed radiography digital system. Results showed that doses between centres varied from 30% for chest LAT to 250% for chest PA examination. With the digital image quality criteria still under discussion, and with the post-processing parameters and/or image documentations varying, any dose comparisons between conventional/digital systems, as well as dose comparisons between different centre using digital units, are difficult. Clinical trials are required in order to define reference levels associated with quality of digital image necessary to address specific clinical requirements.     

A comparison of primary stakeholders’ views on the deployment of biometric technologies in border management: Case study of SMart mobILity at the European land borders

Advances in technology have a substantial impact on every aspect of our lives, ranging from the way we communicate to the way we travel. The Smart mobility at the European land borders (SMILE) project is geared towards the deployment of biometric technologies to optimize and monitor the flow of people at land borders. However, despite the anticipated benefits of deploying biometric technologies in border control, there are still divergent views on the use of such technologies by two primary stakeholders–travelers and border authorities. In this paper, we provide a comparison of travelers' and border authorities' views on the deployment of biometric technologies in border management. The overall goal of this study is to enable us to understand the concerns of travelers and border guards in order to facilitate the acceptance of biometric technologies for a secure and more convenient border crossing. Our method of inquiry consisted of in-person interviews with border guards (SMILE project's end users), observation and field visits (to the Hungarian-Romanian and Bulgarian-Romanian borders) and questionnaires for both travelers and border guards. As a result of our investigation, two conflicting trends emerged. On one hand, border guards argued that biometric technologies had the potential to be a very effective tool that would enhance security levels and make traveler identification and authentication procedures easy, fast and convenient. On the other hand, travelers were more concerned about the technologies representing a threat to fundamental rights, personal privacy and data protection.     

How accurate are policy document mentions? A first look at the role of altmetrics database

Scientometrics - Policy document mention is considered to indicate the significance and societal impact of scientific product. However, the accuracy of policy document altmetrics data needs to be...     

Digitalization of agriculture: A way to solve the food problem or a trolley dilemma?

The high potential of digital applications for agriculture generates enthusiasm about the future of food production. Some view the intelligence offered by digital tools as a way to solve the still pressing food problem. Nevertheless, social, ethical, political, cultural, and environmental concerns associated with digitalization loom large. In this article, using as a framework the artificial trolley dilemma – a situation in which one has to decide about the rightness of putting at risk someone trying to avoid some obvious and imminent noxious effects to a larger group of people – we present the promises and perils of agricultural digitalization. We also point out the need to develop new trajectories for the digital agricultural revolution that ensure the increase of food production without severe negative societal impacts. Although digitalization is sometimes viewed as a panacea for boosting the transition of agrifood production towards more sustainable paradigms, the trade-off may be complicated and requires in-depth analyses excavating the multiple rationales in digitalizing farming. Today, there is a need for science to prove that digitalization does have society-wide positive impacts. On the other side of the coin, the assessment and the estimation of the magnitude of the externalities that digital technologies may have require the development and application of robust evaluation methods. Finally, policies must emphasize the need to provide inclusive and open spaces for agricultural digitalization.     

Home institution bias in the New England Journal of Medicine? A noninferiority study on citation rates

Scientometrics - Recently, in the four top journals of humanities, an institutional bias towards publication of authors from Harvard and Yale was shown. The New England Journal of Medicine (NEJM)...     

A histomorphometric study on collagen-apatite composite as a graft material: the influence of gap size at the titanium–bone interface in animal model

The purpose of this study was to evaluate the healing process of collagen-apatite composite (CAC) at the titanium–bone interface in animal model. Small gaps (0.5 or 1.0 mm-sized wells) were prepared in the epoxy-resin block implants coated with pure titanium. The gaps were filled with CAC or demineralized freeze-dried bone (DFDB). The titanium-coated epoxy-resin block implants were inserted in the tibia of rabbit for 4 weeks or 8 weeks. The microscopic features of bony healing process in the grafted gaps were examined and analyzed. In the histomorphometric analysis, CAC group showed higher fraction of newly-formed bone than DFDB group in both 0.5 and 1.0 mm gap subgroup at 4-week specimen (P < 0.05). In the transmission electron microscopic examinations, osteoblasts of the newly-formed bone of CAC group showed more cellular activity than that of DFDB group. From the results, it was expected that CAC had more beneficial property on early bony healing process than DFDB at the titanium–bone interface.     

How well does the Rayleigh model describe the E-vector distribution of skylight in clear and cloudy conditions? A full-sky polarimetric study

We present the first high-resolution maps of Rayleigh behavior in clear and cloudy sky conditions measured by full-sky imaging polarimetry at the wavelengths of 650 nm (red), 550 nm (green), and 450 nm (blue) versus the solar elevation angle thetas. Our maps display those celestial areas at which the deviation deltaalpha = /alphameas - alphaRyleigh/ is below the threshold alphathres = 5 degrees, where alphameas is the angle of polarization of skylight measured by full-sky imaging polarimetry, and alphaRayleigh is the celestial angle of polarization calculated on the basis of the single-scattering Rayleigh model. From these maps we derived the proportion r of the full sky for which the single-scattering Rayleigh model describes well (with an accuracy of deltaalpha = 5 degrees) the E-vector alignment of skylight. Depending on thetas, r is high for clear skies, especially for low solar elevations (40% < r < 70% for thetas < or = 13 degrees). Depending on the cloud cover and the solar illumination, r decreases more or less under cloudy conditions, but sometimes its value remains remarkably high, especially at low solar elevations (rmax = 69% for thetas = 0 degrees). The proportion r of the sky that follows the Rayleigh model is usually higher for shorter wavelengths under clear as well as cloudy sky conditions. This partly explains why the shorter wavelengths are generally preferred by animals navigating by means of the celestial polarization. We found that the celestial E-vector pattern generally follows the Rayleigh pattern well, which is a fundamental hypothesis in the studies of animal orientation and human navigation (e.g., in aircraft flying near the geomagnetic poles and using a polarization sky compass) with the use of the celestial alpha pattern.     

Going Green at West Point: Is It Economically Beneficial? A Cost-Benefit Analysis of Installing a Wind Farm at the United States Military Academy

Abstract:

In 2007, BQ Energy communicated an idea to the United States Military Academy (USMA) at West Point, NY, about the construction of a 12.5 MW wind farm for electricity production on the western edge of its property in the training grounds near Camp Buckner. Such a project would bring educational, strategic, and potentially economic benefits to USMA, in addition to the obvious environmental benefits that would be realized by the Hudson Valley region. This article describes a quantitative approach to answer why it is financially beneficial for West Point to allow the installation of a wind farm on its property.     

On the influence of nanoparticles as addition to the A356 aluminum-alloy: Is it acting as a refining or strengthening mechanism?

The effect induced by adding nanoparticles to cast hypo-eutectic aluminum 7 % silicon alloys (A356) is continually reported to show enhanced mechanical properties. The experimental results show a strengthening effect associated with an increase in ductility and/or toughness, induced by adding nanoparticles. The aim of this work is to add a contribution towards understanding the strengthening effect observed in the nanoparticles-reinforced A356 alloy. This is done by calculating the conventional incremental summation of several strengthening mechanisms contributing to strengthening and reinforcement in composites. The results obtained by applying the mathematical calculations are compared with the experimental results reported in literature. Based on the mathematical approach, this work shows that the main strengthening mechanisms acting for metal matrix nano composites (MMNCs) are those contributing to the strengthening of the matrix. These result from contributions by Orowan strengthening and coefficient of thermal expansion (CTE) and elastic modulus (EM) mismatch.     

What advantages of blockchain affect its adoption in the elderly care industry? A study based on the technology–organisation–environment framework

Blockchain technology is considered a logical solution to the problems of security, privacy and trust in the collection, storage and sharing of data related to the elderly in the elderly care industry (ECI); however, its adoption in the ECI remains in its initial stage. To improve the efficiency of adopting this technology in the ECI and to facilitate decision-making by managers, this study combines the diffusion of innovation theory and the technology–organisation–environment framework models to study the factors affecting blockchain adoption intention in the ECI. In addition, the direct predictors of the relative advantages of blockchain technology in the ECI are explored. Through a questionnaire survey of 124 elderly care institutions in China, we collected 181 valid questionnaires and analysed them using a partial least squares regression structural equation model. The results show that relative advantage, corporate social responsibility, top management support and organisational readiness have a positive effect on blockchain adoption intention in the ECI, while the effects of complexity, government support and competitive pressure are insignificant. However, competitive pressure and government support can indirectly promote blockchain adoption intention by influencing top management support. Furthermore, technology trust and information security positively affect the relative advantages of blockchain technology and indirectly affect blockchain adoption intention, while privacy protection is insignificant.     

Are aggressive people aggressive drivers? A study of the relationship between self-reported general aggressiveness, driver anger and aggressive driving

In this study the relationships among self-reported general aggressiveness, impulsiveness, driver anger, and aggressive responses to anger-provoking situations on the road were studied. The British version of a driver anger scale (UK DAS), aggression questionnaire (AQ), and an impulsiveness questionnaire (I7) together with background questions (gender, age, annual mileage) were administered to a sample of 270 British drivers. Variation in strength of correlations between anger and aggressive reactions in the 21 UK DAS items showed that the relationship between driver anger and aggression depends in part on the characteristics of the situation. In addition, three path models for describing the relationships among the measures were constructed separately for women and men. The models suggested that the effects of verbal aggressiveness on self-reported driver aggression were mediated by driver anger whereas physical aggressiveness was directly related to aggressive behaviour. Age was negatively related to both driver anger and aggression among men whereas annual mileage was negatively related to aggression among women. The models constructed indicate that aggressive driver behaviour is a complex phenomenon with a range of psychological causes.     

How to investigate the historical roots and evolution of research fields in China? A case study on iMetrics using RootCite

Scientometrics - This paper aimed to provide an approach to investigate the historical roots and evolution of research fields in China by extending the reference spectroscopy year spectroscopy...     

Bringing the doctoral thesis by published papers to the Social Sciences and the Humanities: A quantitative easing? A small study of doctoral thesis submission rules and practice in two disciplines in the UK

Scientometrics - This paper examines how an alternative to the traditional monograph form of the doctoral thesis is emerging that reflects a new approach to the valuation and designation of...     

A study on the oxidation behavior of HVOF sprayed NiCrAlY–0.4 wt.% CeO2 coatings on superalloys at elevated temperature

The high temperature oxidation behavior of HVOF sprayed ceria added NiCrAlY coatings on superalloys has been studied. Oxidation kinetics of the bare and coated superalloys in air at 900 °C under cyclic conditions was investigated. X-ray diffraction, field emission scanning electron microscope with energy dispersive spectroscopy and X-ray mapping were used to analyse the scales formed on the surface of the oxidised samples. The NiCrAlY–0.4 wt.% CeO₂ coated specimen showed negligible microspalling of the scales. The incorporation of ceria in NiCrAlY powder has contributed to the development of adherent oxide scale, in the coating, at elevated temperature and provided the better oxidation resistance.