Towards a hydrogen economy in Romania: Statistics,technical and scientific general aspects

The present work features an analysis of the current state of Romania's current policy in the context of hydrogen economy. The possibilities and limitations concerning the transition towards the hydrogen economy in Romania are discussed taking into account a number of aspects, including: the degree of development of the electric power infrastructure, aspects from petrochemical and agrochemical industry, transport infrastructure, socioeconomic development indicators, activity and dynamics of the scientific community and attitude of central authorities. All these are important aspects that contribute to technology deployment. The article presents both advantages and disadvantages from Romania, provides concrete examples, gives information, makes comparisons and provides recommendations, taking into account national aspects. Key areas of promise for hydrogen technologies in Romania are identified. The paper concludes with recommendations for actions in order to begin the process of transition towards a hydrogen economy.     

A mathematical model for skin burn injury induced by radiation heating

We modify the Pennes model by taking into account the thermal relaxation time of biological tissue. Specifically, we employ the Maxwell–Cattaneo thermal flux law, in conjunction with the fourth power law, to model the effects of high thermal radiation on such skin. The skin is considered to be a 3D triple-layered structure with embedded dendritic countercurrent multi-level blood vessels, artery and vein, where the dimensions and blood flow of the multi-level blood vessels are determined based on the constructal theory of multi-scale tree-shaped heat exchangers. The method is illustrated by a numerical example.     

Solution-processed single walled carbon nanotube electrodes for organic thin-film transistors

Airbrushed single walled carbon nanotube (SWCNT) thin films with sheet resistivity <1 kΩ/sq. and transparency >80% are used as electrodes for pentacene and regioregular poly(3-hexylthiophene) (P3HT) thin-film transistors (TFTs). Airbrushed SWCNT electrodes show low contact resistance in a bottom-contact configuration, comparable to (in the case of P3HT) or lower than (in the case of pentacene) Au bottom-contacts. The results show that airbrushed CNT electrodes yield similar performance to CVD-grown CNT electrodes.     

Scalable Microgravity Simulator Used for Long-Term Musculoskeletal Cells and Tissue Engineering

We introduce a new benchtop microgravity simulator (MGS) that is scalable and easy to use. Its working principle is similar to that of random positioning machines (RPM), commonly used in research laboratories and regarded as one of the gold standards for simulating microgravity. The improvement of the MGS concerns mainly the algorithms controlling the movements of the samples and the design that, for the first time, guarantees equal treatment of all the culture flasks undergoing simulated microgravity. Qualification and validation tests of the new device were conducted with human bone marrow stem cells (bMSC) and mouse skeletal muscle myoblasts (C2C12). bMSC were cultured for 4 days on the MGS and the RPM in parallel. In the presence of osteogenic medium, an overexpression of osteogenic markers was detected in the samples from both devices. Similarly, C2C12 cells were maintained for 4 days on the MGS and the rotating wall vessel (RWV) device, another widely used microgravity simulator. Significant downregulation of myogenesis markers was observed in gravitationally unloaded cells. Therefore, similar results can be obtained regardless of the used simulated microgravity devices, namely MGS, RPM, or RWV. The newly developed MGS device thus offers easy and reliable long-term cell culture possibilities under simulated microgravity conditions. Currently, upgrades are in progress to allow real-time monitoring of the culture media and liquids exchange while running. This is of particular interest for long-term cultivation, needed for tissue engineering applications. Tissue grown under real or simulated microgravity has specific features, such as growth in three-dimensions (3D). Growth in weightlessness conditions fosters mechanical, structural, and chemical interactions between cells and the extracellular matrix in any direction.     

Size-controllable synthesis of chromium oxyhydroxide nanomaterials using a soft chemical hydrothermal route

Chromium oxyhydroxide nanomaterials were synthesised through a simple soft chemical hydrothermal method. The chromium oxyhydroxide materials display platelet morphology with clear edges, ~11 nm in diameter. CrO(OH) nanomaterials synthesised under different conditions were fully characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM) combined with selected area electron diffraction (SAED), scanning electron microscopy (SEM), BET specific surface area analysis, X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA). Bonding of the trivalent chromium from the oxyhydroxide nanomaterials was defined through the analysis of their high resolution XPS spectra for Cr 2p_3/2 and O 1s. The thermal stability of the nanomaterials CrO(OH) was established. This research has developed methodology for the synthesis of chromium oxyhydroxide nanoplates.     

On the optimum support size in meshfree methods: A variational adaptivity approach with maximum‐entropy approximants

We present a method for the automatic adaption of the support size of meshfree basis functions in the context of the numerical approximation of boundary value problems stemming from a minimum principle. The method is based on a variational approach, and the central idea is that the variational principle selects both the discretized physical fields and the discretization parameters, here those defining the support size of each basis function. We consider local maximum‐entropy approximation schemes, which exhibit smooth basis functions with respect to both space and the discretization parameters (the node location and the locality parameters). We illustrate by the Poisson, linear and non‐linear elasticity problems the effectivity of the method, which produces very accurate solutions with very coarse discretizations and finds unexpected patterns of the support size of the shape functions. Copyright © 2009 John Wiley & Sons, Ltd.     

Assessing the potential for a wind power incentive for remote villages in Canada

This paper discusses the uptake potential for a wind–diesel production incentive designed specifically for Canadian northern and remote communities. In spite of having over 300 remote communities with extremely high electricity costs, Canada has had little success in developing remote wind energy projects. Most of Canada’s large-scale wind power has been developed as a direct result of a Federal production incentive implemented in 2002. Using this incentive structure as a successful model, this paper explores how an incentive tailored to remote wind power could be deployed. Micro-power simulations were done to demonstrate that the production incentive designed by the Canadian Wind Energy Association would cost on average $4.7 $Cdn million and could be expected to result in 14.5 MW of wind energy projects in remote villages in Canada over a 10 year period, saving 11.5 $Cdn million dollars in diesel costs annually, displacing 7600 tonnes of CO_2eq emissions and 9.6 million litres of diesel fuel every year.     

Unifying running-key approach and logistic map to generate enciphering sequences

The paper presents a new approach to generating enciphering sequences useful in information protection, with an illustration on images. The procedure is both theoretically and experimentally supported by combining elements derived from the running-key cipher, information theory and statistics. The enciphering key generator is based on the logistic map, and its theoretical properties are demonstrated by statistical tests. The new enciphering sequences comply with the fair coin model, and the randomly chosen initial conditions of the logistic map (defining the enciphering sequence) can be part of the secret key. Although dealing with a particular case of chaotic system, the paper contains the necessary elements so that the overall procedure can be applied to other chaotic maps (e.g., tent map).