Direct programming of a central pattern generator for periodic motions by touching

Much of the literature shows that Central Pattern Generators (CPGs) are a good approach for generating periodic motions for legged robots. In most of the presented works the numerous CPG parameters are set by automatic techniques like genetic algorithms. This gives the user little control over the resulting motions, since all of the desired features of the motion must be encoded by a fitness/score function. In this paper we present the idea of setting the CPG parameters by interaction with the user, in particular by using the tactile interaction. Key elements of the system are a CPG network, a touch protocol and a self-collision prevention system. In this paper we present a practical implementation of each element that confirms the feasibility of the method.     

Extracellular Matrix Composition Modulates the Responsiveness of Differentiated and Stem Pancreatic Cancer Cells to Lipophilic Derivate of Gemcitabine

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease. Gemcitabine (GEM) is used as the gold standard drug in PDAC treatment. However, due to its poor efficacy, it remains urgent to identify novel strategies to overcome resistance issues. In this context, an intense stroma reaction and the presence of cancer stem cells (CSCs) have been shown to influence PDAC aggressiveness, metastatic potential, and chemoresistance. Methods: We used three-dimensional (3D) organotypic cultures grown on an extracellular matrix composed of Matrigel or collagen I to test the effect of the new potential therapeutic prodrug 4-(N)-stearoyl-GEM, called C18GEM. We analyzed C18GEM cytotoxic activity, intracellular uptake, apoptosis, necrosis, and autophagy induction in both Panc1 cell line (P) and their derived CSCs. Results: PDAC CSCs show higher sensitivity to C18GEM treatment when cultured in both two-dimensional (2D) and 3D conditions, especially on collagen I, in comparison to GEM. The intracellular uptake mechanisms of C18GEM are mainly due to membrane nucleoside transporters’ expression and fatty acid translocase CD36 in Panc1 P cells and to clathrin-mediated endocytosis and CD36 in Panc1 CSCs. Furthermore, C18GEM induces an increase in cell death compared to GEM in both cell lines grown on 2D and 3D cultures. Finally, C18GEM stimulated protective autophagy in Panc1 P and CSCs cultured on 3D conditions. Conclusion: We propose C18GEM together with autophagy inhibitors as a valid alternative therapeutic approach in PDAC treatment.     

Secure printing

Business and transaction documents printed by users or in captive printing and mailing operations are susceptible to security breaches. Awareness of the related risks is crucial for corporations.     

Air flow in a tube with a diverging inlet: I. Development of the turbulent velocity profile

The results from an experimental study of the development of air velocity profiles in a vertical 6.25-in. I. D., 28.5-ft. long aluminum tube with a diverging conical entrance are reported. Using the axial development of centerline velocity as a starting-length criterion, a maximum and asymptotic value was approached at 40 diameters from the tube entrance. The starting length was found to increase with increasing Reynolds number. The large center-line velocity associated with the jetting of air from a 1-in. I. D. tube into the diverging conical entrance enabled a more rapid development of the velocity profile than for the well known case of a converging rounded entrance. A limited comparison of undeveloped and fully developed velocity profiles in the turbulent core region of the 6.25-in. tube was also made over Reynolds numbers from 9,000 to 55,000.     

Photoluminescence of carbon-induced Ge islands in silicon

Reducing the size of germanium islands improves their optical properties. The spatially strong localised holes in the islands are more uncertain in momentum and thereby the probability of direct optical transitions is enhanced. Carbon predepositon onto Si has been shown to reduce the size of germanium islands. We have studied such islands grown by molecular beam epitaxy. The germanium islands show an intense PL-signal, which is typically more than one order of magnitude larger in intensity than the PL from silicon–germanium quantum wells. Reducing the amount of Ge from 3.4 monolayer (ML) to 1.0 ML results in a PL blueshift from 0.81 to 1.08 eV in conjunction with a narrowing of the PL peak. The blueshift indicates a reduction in the size of the germanium islands, which was confirmed by TEM. Increasing the C coverage from 0.2 to 0.3 ML leads to a red shifted PL. This is attributed to a change in the aspect ratio of the islands with the result of an increased vertical island height.     

High-performance PIN photodiodes on TMAH thinned silicon wafers

The electro-optical characteristics of PIN photodiodes fabricated on high-resistivity silicon substrates locally thinned by bulk micromachining techniques are discussed. Experimental results and numerical simulations demonstrate that devices fabricated by the proposed approach have leakage current, quantum efficiency and speed performance comparable to the best commercially available Si PIN photodiodes, with the additional advantage of possible back-side illumination, making them suitable for the implementation of two-dimensional arrays having a read-out electronic chip connected to the front-side.     

Optimization of Vacuum Impregnation with Calcium Lactate of Minimally Processed Melon and Shelf‐Life Study in Real Storage Conditions

Vacuum impregnation (VI) is a processing operation that permits the impregnation of fruit and vegetable porous tissues with a fast and more homogeneous penetration of active compounds compared to the classical diffusion processes. The objective of this research was to investigate the impact on VI treatment with the addition of calcium lactate on qualitative parameters of minimally processed melon during storage. For this aim, this work was divided in 2 parts. Initially, the optimization of process parameters was carried out in order to choose the optimal VI conditions for improving texture characteristics of minimally processed melon that were then used to impregnate melons for a shelf‐life study in real storage conditions. On the basis of a 2³ factorial design, the effect of Calcium lactate (CaLac) concentration between 0% and 5% and of minimum pressure (P) between 20 and 60 MPa were evaluated on color and texture. Processing parameters corresponding to 5% CaLac concentration and 60 MPa of minimum pressure were chosen for the storage study, during which the modifications of main qualitative parameters were evaluated. Despite of the high variability of the raw material, results showed that VI allowed a better maintenance of texture during storage. Nevertheless, other quality traits were negatively affected by the application of vacuum. Impregnated products showed a darker and more translucent appearance on the account of the alteration of the structural properties. Moreover microbial shelf‐life was reduced to 4 d compared to the 7 obtained for control and dipped samples.     

Piezo-valve controller for the gas inlet system of the fusion experiment Wendelstein 7-X

The gas inlet system of the fusion experiment Wendelstein 7-X (W7-X) comprises eleven gas inlets around the torus for controlled provision with working gases in the torus. This fast gas inlet system is designed for different operating modes of W7-X, from short discharges with only a few seconds durations to steady state plasma operation with operation time of 30 min. Piezo valves of type FGIS (FGIS: Fast Gas Injection System from General Atomics) are used as actuators for the W7-X gas inlet system.The design of an intelligent control unit for the FGIS Piezo valves are introduced and discussed. The integration of the valve controller units into the W7-X control component “W7-X gas inlet” and their planned application in an experiment run is described.     

Low-energy district heating in energy-efficient building areas

This paper presents an innovative low-energy district heating (DH) concept based on low-temperature operation. The decreased heating demand from low-energy buildings affects the cost-effectiveness of traditionally-designed DH systems, so we carried out a case study of the annual energy performance of a low-energy network for low-energy houses in Denmark. We took into account the effect of human behaviour on energy demand, the effect of the number of buildings connected to the network, a socio-economic comparison with ground source heat pumps, and opportunities for the optimization of the network design, and operational temperature and pressure. In the north-European climate, we found that human behaviour can lead to 50% higher heating demand and 60% higher heating power than those anticipated in the reference values in the standard calculations for energy demand patterns in energy-efficient buildings. This considerable impact of human behaviour should clearly be included in energy simulations. We also showed that low-energy DH systems are robust systems that ensure security of supply for each customer in a cost-effective and environmentally friendly way in areas with linear heat density down to 0.20 MWh/(m year), and that the levelized cost of energy in low-energy DH supply is competitive with a scenario based on ground source heat pumps. The investment costs represent up to three quarters of the overall expenditure, over a time horizon of 30 years; so, the implementation of an energy system that fully relies on renewable energy needs substantial capital investment, but in the long term this is sustainable from the environmental and socio-economic points of view. Having demonstrated the value of the low-energy DH concept, we evaluated various possible designs with the aim of finding the optimal solution with regard to economic and energy efficiency issues. Here we showed the advantage of low supply and return temperatures, their effect on energy efficiency and that a DH design that relies on low-temperature operation is superior to a design based on low-flow operation. The total primary energy use in the best design was 14.3% lower than the primary energy use for standard, recently designed networks, and distribution heat losses were halved. Moreover, the exploitation of the entire available pressure by means of careful network design decreased the average pipe size required, which slightly lowers the investment costs for purchasing and laying the pipelines in the ground. This low-temperature DH concept fits the vision of the future energy-sustainable society.