Modelling the coefficient of thermal expansion in Ni-based superalloys and bond coatings

The coefficient of thermal expansion (CTE) of nickel-based superalloys and bond coat layers was modelled by considering contributions from their constituent phases. The equilibrium phase composition of the examined materials was determined using thermodynamic equilibrium software with an appropriate database for Ni-based alloys, whereas the CTE and elastic properties of the principal phases were modelled using published data. The CTEs of individual phases were combined using a number of approaches to determine the CTE of the phase aggregate. As part of this work, the expansion coefficients of the superalloy IN-738LC and bond coat Amdry-995 were measured as a function of temperature and compared with the model predictions. The predicted values were also validated with the published data for the single-crystal superalloy CMSX-4 and a number of other Ni-based alloy compositions at 1000 K. A very good agreement between experiment and model output was found, especially up to 800  $$^\circ$$ � C. The modelling approaches discussed in this paper have the potential to be an extremely useful tool for the industry and for the designers of new coating systems

Doxorubicin loaded magnesium oxide nanoflakes as ph dependent carriers for simultaneous treatment of cancer and hypomagnesemia

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Doxorubicin (DOX) is an anticancer drug commonly used in treating cancer; however, it has severe cytotoxicity effects. To overcome both the adverse effects of the drug and mineral deficiency (i.e., hypomagnesemia) experienced by cancer patients, we have developed magnesium oxide (MgO) nanoflakes as drug carriers and loaded them with DOX for use as a targeted drug delivery (TDD) system for potential application in cancer therapy. The synthesis employed herein affords pure, highly porous MgO nanoparticles that are void of the potentially harmful metal contaminants often discussed in the literature. Purposed for dual therapy, the nanoparticles exhibit an impressive 90% drug loading capacity with pH dependent drug releasing rates of 10% at pH 7.2, 50.5% at pH 5.0, and 90.2% at pH 3. Results indicate that therapy is achievable via slow diffusion where MgO nanoflakes degrade (i.e., dissolve) under acidic conditions releasing the drug and magnesium ions to the cancerous region. The TDD system therefore minimizes cytotoxicity to healthy cells while supplying magnesium ions to overcome hypomagnesemia

Modelling of microstructural evolution in multi-layered overlay coatings

Functionally graded, multi-layered coatings are designed to provide corrosion protection over a range of operating conditions typically found in industrial gas turbines. A model incorporating diffusion, equilibrium thermodynamics and oxidation has been developed to simulate the microstructural evolution within a multi-layered coating system. The phase and concentration profiles predicted by the model have been compared with an experimental multi-layered system containing an Al-rich outer layer, a Cr-enriched middle layer and an MCrAlY-type inner layer deposited on a superalloy substrate. The concentration distribution and many microstructural features observed experimentally can be predicted by the model. The model is expected to be useful for assessing the microstructural evolution of multilayer coated systems which can be potentially used on industrial gas turbine aerofoils

Values and Diversity of Organisational Work Ethicality: Lessons Learnt from Sri Lankan Entrepreneurs

The aim of this paper is to examine values as a component of organisational work ethicality, uncovering the contextual realities of values and explore the diversity of work ethicality in the entrepreneurial context in Sri Lanka. Organisational work ethicality is explained through egoistic work ethicality, utilitarian work ethicality and deontological work ethicality. With a view to get a deeper understanding of the diversity of organisational work ethicality, a qualitative approach is adopted. Twelve entrepreneurs were selected for in-depth interviews. A thematic analysis was carried out for field notes with the support of NVivo 6 version. Findings of this study reveal that the entrepreneurial thinking and their interpretations derived different social meanings of organisational work ethicality. The final outcome shows that rather than single dominant work ethicality, a combination of work ethicalities was preferred by most of the entrepreneurs. Within this mix of ethicalities, deontological ethicality and egoistic work ethicality seem to be equally practised by the entrepreneurs. The utilitarian ethicality seems to be practised at a minimum level. As a result, the implicational value of this study lies on at the organisational level and policy making level to rethink and reestablish a mechanism to improve ethical aspects of the businesses in order to maximise social well-being while doing the right things for the society and strengthening shareholders’ protection. KeywordsBusiness Ethics, Business Practices, Deontological Work Ethicality,Egoistic Work Ethicality, Entrepreneur, Utilitarian Work Ethicality, Value

Modelling the coefficient of thermal expansion in Ni based superalloys and bond coatings

The coefficient of thermal expansion (CTE) of nickel based superalloys and bond coat layers was modelled by considering contributions from their constituent phases. The equilibrium phase composition of the examined materials was determined using thermodynamic equilibrium software with an appropriate database for Ni-based alloys, whereas the CTE and elastic properties of the principal phases were modelled using published data. The CTEs of individual phases were combined using a number of approaches to determine the CTE of the phase aggregate. As part of this work, the expansion coefficients of the superalloy IN-738LC and bond coat Amdry-995 were measured as a function of temperature and compared with the model predictions. The predicted values were also validated with the published data for the single-crystal superalloy CMSX-4 and a number of other Ni based alloy compositions at 1000 K. Very good agreement between experiment and model output was found, especially up to 800°C. The modelling approaches discussed in this paper have the potential to be an extremely useful tool for the industry and for the designers of new coating systems

Development of photo catalytic active building materials using zno nanorods

In many urban cities, the pollutants concentration at street level is quite high because of the dispersion of the exhaust generated by a large number of vehicles is hindered by surrounding tall buildings. Control of these pollutions has become a pressing need for the well-being of society. Many methods have been developed to control these pollutions. Currently, there is an increasing interest in the control of urban pollution level by using construction materials containing photocatalytic nanomaterials, without changing original performance of the building structure. The photocatalytic materials used in the building materials for the purification process are efficient to remove the contaminants such as NOx and VOC. Many works have been concerned with the application of different types of nanomaterials in photocatalytic processes. This paper presents the systematic study on the photocatalytic activity of ZnO nanorods on construction materials. In this method, ZnO nanorods were successfully synthesized by a wet chemical route. Systematic experiments were carried out to investigate the photocatalytic activity of the samples. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). It has been found that the ZnO nanoflowers contain many radial nanorods with the diameter of 100 nm and the length of 1–1.5 μm and these ZnO single-crystalline nanorods with wurtzite structure grow along the [ 0 0 1] direction. The formation mechanism of ZnO nanoflowers and nanorods was initially interpreted in terms of the general theory of the crystal nucleation and crystal growth direction. ZnO with flower-like morphology exhibited improved ability on the photocatalytic degradation

Advances in Natural Language Question Answering: A Review

Question Answering has recently received high attention from artificial intelligence communities due to the advancements in learning technologies. Early question answering models used rule-based approaches and moved to the statistical approach to address the vastly available information. However, statistical approaches are shown to underperform in handling the dynamic nature and the variation of language. Therefore, learning models have shown the capability of handling the dynamic nature and variations in language. Many deep learning methods have been introduced to question answering. Most of the deep learning approaches have shown to achieve higher results compared to machine learning and statistical methods. The dynamic nature of language has profited from the nonlinear learning in deep learning. This has created prominent success and a spike in work on question answering. This paper discusses the successes and challenges in question answering question answering systems and techniques that are used in these challenges

Thermal Conductivity Enhancement of Al2O3 Nanofluid in Ethylene Glycol and Water Mixture

AbstractThe ability of nanofluids that exhibits enhanced thermal performance is acknowledged by researchers through studies since decades ago. However, the observation of thermal properties for nanofluids in water and ethylene glycol based is not fully explored yet. Hence, this paper presents the thermal conductivity of water and ethylene glycol (EG) based Al2O3 nanofluid. The 13 nm sized Al2O3 nanoparticles were dispersed into three different volume ratio of water: EG such as 40:60, 50:50 and 60:40 using a two-step method. The measurement of thermal conductivity was performed using KD2 Pro Thermal Properties Analyzer at working temperatures of 30 to 70 ̊C for volume concentration of 0.5 to 2.0%. The results indicate that the thermal conductivity increases with the increase of nanofluid concentration and temperature. While the percentage of ethylene glycol increase, the range of thermal conductivity decreases due to ethylene glycol properties. The measurement data of the nanofluids give maximum enhancement of thermal conductivity at condition 2.0% volume concentration, temperature of 70 ̊C and for all base fluid

Deterministic processes vary during community assembly for ecologically dissimilar taxa

The continuum hypothesis states that both deterministic and stochastic processes contribute to the assembly of ecological communities. However, the contextual dependency of these processes remains an open question that imposes strong limitations on predictions of community responses to environmental change. Here we measure community and habitat turnover across multiple vertical soil horizons at 183 sites across Scotland for bacteria and fungi, both dominant and functionally vital components of all soils but which differ substantially in their growth habit and dispersal capability. We find that habitat turnover is the primary driver of bacterial community turnover in general, although its importance decreases with increasing isolation and disturbance. Fungal communities, however, exhibit a highly stochastic assembly process, both neutral and non-neutral in nature, largely independent of disturbance. These findings suggest that increased focus on dispersal limitation and biotic interactions are necessary to manage and conserve the key ecosystem services provided by these assemblages