A monolithic computational approach to thermo‐structure interaction

In the present work, a monolithic solution approach for thermo‐structure interaction problems motivated by the challenging application of the behaviour of rocket nozzles is proposed. Structural and thermal fields are independently discretised via finite elements. The resulting system of equations is solved via a monolithic thermo‐structure interaction scheme, which is constructed by a block Gauss–Seidel preconditioner in combination with algebraic multigrid methods. The proposed method is tested for four numerical examples, the second Danilovskaya problem, a simplified rocket nozzle configuration, an internally loaded hollow sphere, and a fully three‐dimensional nozzle configuration of a subscale thrust chamber. Good agreement of the numerical results with results from the literature is observed. Furthermore, it is shown that the monolithic solution algorithm can handle the complete range of the parameter spectrum, whereas partitioned algorithms are limited to a certain parameter range only. Moreover, the monolithic algorithm exhibits improved efficiency and robustness compared to partitioned algorithms. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparing Transition-Edge Sensor Response Times in a Modified Contact Scheme with Different Support Beams

We present measurements of the thermal conductance, G, and effective time constants, \(\tau \) , of three transition-edge sensors (TESs) populated in arrays operated from 80–87 mK with T \(_\mathrm{C}\)   \(\sim \)  120 mK. Our TES arrays include several variations of thermal architecture enabling determination of the architecture that demonstrates the minimum noise equivalent power, the lowest \(\tau \) , and the trade-offs among designs. The three TESs we report here have identical Mo/Cu bilayer thermistors and wiring structures, while the thermal architectures are: (1) a TES with straight support beams of 1 mm length, (2) a TES with meander support beams of total length 2 mm and with two phonon-filter blocks per beam, and (3) a TES with meander support beams of total length 2 mm and with six phonon-filter blocks per beam. Our wiring scheme aims to lower the thermistor normal state resistance R \(_{N}\) and increase the sharpness of the transition \(\alpha =\)  dlogR/dlogT at the transition temperature T \(_\mathrm{C}\) . We find an upper limit of \(\alpha \) given by ( \(25\pm 10\) ), and G values of 200 fW/K for (1), 15 fW/K for (2), and 10 fW/K for (3). The value of \(\alpha \) can be improved by slightly increasing the length of our thermistors.     

A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality

Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.     

Spin-Wave Optics in YIG Realized by Ion-Beam Irradiation

Direct focused-ion-beam writing is presented as an enabling technology for realizing functional spin-wave devices of high complexity, and demonstrate its potential by optically-inspired designs. It is shown that ion-beam irradiation changes the characteristics of yttrium iron garnet films on a submicron scale in a highly controlled way, allowing one to engineer the magnonic index of refraction adapted to desired applications. This technique does not physically remove material, and allows rapid fabrication of high-quality architectures of modified magnetization in magnonic media with minimal edge damage (compared to more common removal techniques such as etching or milling). By experimentally showing magnonic versions of a number of optical devices (lenses, gratings, Fourier-domain processors) this technology is envisioned as the gateway to building magnonic computing devices that rival their optical counterparts in their complexity and computational power.     

Permeation Through Plastic Dangerous Goods Packaging During Transport in Freight Containers – Detection of Potentially Explosive Mixtures in Containers Under Normal Conditions of Carriage

The key point within the scope of this research project was to find out whether there was a risk of creating an explosive atmosphere by permeation of flammable liquid compounds during transport of dangerous goods in freight containers under normal conditions of carriage. Therefore, all aspects that had an influence on the formation of such an atmosphere had to be considered. The most important influencing factors were permeation, air change in the freight container and ambient temperature. The first step was to investigate the permeation with different packaging materials, charge and temperatures. Furthermore, the air change rates of different freight containers were measured. A few climate tests with containers on ships, e.g. to Singapore, were performed to assess normal conditions of carriage. Another important point was measuring the solvent (toluene) concentration in the gas phase in a freight container loaded with plastic intermediate bulk containers (IBCs) filled with toluene. To confirm that the measured values were in the right range, the toluene concentration in the gas phase in a container was calculated with different packaging materials, air change rates and temperatures. The results of the measurements and calculations have shown that safety layers in the packaging wall, e.g. the copolymer of ethylene and vinyl alcohol (EVOH) and polyamide, can reduce the rate of permeation by more than a decimal power, but the lower explosive limit of toluene is easily reached within a few hours at 40°C charge temperature if there is no barrier. Copyright © 2012 John Wiley & Sons, Ltd.     

Open innovation in Russian state-owned enterprises

ABSTRACT

This paper studies open innovation practices in Russian state-owned enterprises (SOEs). In 2011, the Russian Government set ambitious goals in science, technology and innovation, and uses its large SOEs as channels to achieve these targets. These initiatives focus on the collaboration among innovation actors and introduce open innovation (OI) principles. Based on a large-scale innovation survey, we compare private enterprises to state-owned peers and present selected case studies. Our data support the claim that Russian SOEs are driving the demand for technology and mainly absorb incoming OI activities. Different to their peers, SOEs extend their OI activities to the country’s knowledge producers, such as research and technology organisations (RTOs), and leading universities. They work on incorporating scientific knowledge that could, indeed, hold the key to globally competitive technological innovations, but also have better capabilities to include business partners.

Abbreviation : OI: Open innovation; SOE: State-owned enterprise; RTO: Research and technology organisation; STI: Science, technology and innovation.     

Polymer-Based Batteries—Flexible and Thin Energy Storage Systems

Batteries have become an integral part of everyday life—from small coin cells to batteries for mobile phones, as well as batteries for electric vehicles and an increasing number of stationary energy storage applications. There is a large variety of standardized battery sizes (e.g., the familiar AA-battery or AAA-battery). Interestingly, all these battery systems are based on a huge number of different cell chemistries depending on the application and the corresponding requirements. There is not one single battery type fulfilling all demands for all imaginable applications. One battery class that has been gaining significant interest in recent years is polymer-based batteries. These batteries utilize organic materials as the active parts within the electrodes without utilizing metals (and their compounds) as the redox-active materials. Such polymer-based batteries feature a number of interesting properties, like high power densities and flexible batteries fabrication, among many more.     

Insights into Theranostic Properties of Titanium Dioxide for Nanomedicine

Titanium dioxide(TiO2)nanostructures exhibit a broad range of theranostic properties that make them attractive for biomedical applications.TiO2 nanostructures promise to improve current theranostic strategies by leveraging the enhanced quantum confinement,thermal conversion,specific surface area,and surface activity.This review highlights certain important aspects of fabrication strategies,which are employed to generate multifunctional TiO2 nanostructures,while outlining post-fabrication techniques with an emphasis on their suitability for nanomedicine.The biodistribution,toxicity,biocompatibility,cellular adhesion,and endocytosis of these nanostructures,when exposed to biological microenvironments,are examined in regard to their geometry,size,and surface chemistry.The final section focuses on recent biomedical applications of TiO2 nanostructures,specifically evaluating therapeutic delivery,photodynamic and sonodynamic therapy,bioimaging,biosensing,tissue regeneration,as well as chronic wound healing.