Corrosion-Induced Concrete Cracking Model Considering Corrosion-Filled Paste

A TCP–TCL model is established to describe the relationship between the thickness of the corrosion-filled paste (CP) and that of the corrosion layer (CL). This model can describe the phenomenon that the corrosion filling in the concrete pores and accumulating at the steel/concrete interface occur synchronously. Based on the TCP–TCL model, a corrosion-induced concrete cracking model, which can quantitatively consider corrosion-filled paste at concrete/steel interface, is proposed. Combined with damage analysis in corrosion-induced cracking process of concrete cover, the model is developed to describe the quantity of steel corrosion required to crack the concrete surface

Nano-Porous Light-Emitting Silicon Chip as a Potential Biosensor Platform

Nano-porous silicon (PS) offers a potential platform for biosensors with benefits both in terms of light emission and the large functional surface area. A light emitting PS chip with a stable and functional surface was fabricated in our laboratory. When protein was deposited on it, the light emission was reduced in proportion to the protein concentration. Based on this property, we developed a rudimentary demonstration of a label-free sensor to detect bovine serum albumin (BSA). A serial concentration of BSA was applied to the light chip and the reduction in light emission was measured. The reduction of the light intensity was linearly related to the concentration of the BSA at concentrations below 10-5 M. The detection limit was 8×10-9 M

Engineering Scheffersomyces segobiensis for palmitoleic acid‐rich lipid production

Palmitoleic acid (POA; C16:1) is an essential high- value ω- 7- conjugated fatty acid with beneficial bioactivities and potential applications in the nu-traceutical and pharmaceutical industries. Previously, the oleaginous yeast Scheffersomyces segobiensis DSM27193 has been identified as a promis-ing production host as an alternative for POA extraction from plant or animal sources. Here, the POA-producing capacity of this host was further expanded by optimizing the fermentation process and molecular strain engineering. Specifically, a dual fermentation strategy (O-S dynamic regulation strategy) focused on the substrate and dissolved oxygen concentration was designed to eliminate ethanol and pyruvate accumulation during fermentation. Key genes influencing POA production, such as jen, dgat, ole were identified on the transcriptional level and were subsequently over-expressed. Furthermore, the phosphoketolase (Xpk)/phosphotransacetylase (Pta) pathway was intro-duced to improve the yield of the precursor acetyl-CoA from glucose. The resulting cell factory SS-12 produced 7.3 g/L of POA, corresponding to an 11-fold increase compared to the wild type, presenting the highest POA titre reported using oleaginous yeast to date. An economic evaluation based on the raw materials, utilities and facility-dependent costs showed that microbial POA production using S. segobiensis can supersede the current extraction method from plant oil and marine fish. This study reports the construction of a promising cell factory and an effective microbial fermentation strategy for commercial POA production

Rotation Symmetry Spontaneous Breaking of Edge States in Zigzag Carbon Nanotubes

Analytical solutions of the edge states were obtained for the (N, 0) type carbon nanotubes with distorted ending bonds. It was found that the edge states are mixed via the distortion. The total energies for N=5 and N>=7 are lower in the asymmetric configurations of ending bonds than those having axial rotation symmetry. Thereby the symmetry is breaking spontaneously. The results imply that the symmetry of electronic states at the apex depends on the occupation; the electron density pattern at the apex could change dramatically and could be controlled by applying an external field.Comment: 19 pages, 3 figure

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

A liquid progressive multifocal lens adjusted by the deformation of a non-uniform elastic membrane due to the variation of liquid pressure

Abstract Background In this paper, a liquid progressive multifocal lens with solid-liquid structure is demonstrated, which mainly consists of two elastic polydimethylsiloxane (PDMS) membranes, a solid substrate and liquid. Methods To realize the adjustment of the focuses progressively, the thickness of one of the membrane is designed non-uniform. By controlling the liquid pressure working on the membranes, the curvature of the membrane can be changed continuously and the power of the lens can be altered simultaneously. In this paper, the structure and a fabrication method of the lens is introduced, and a power distribution model is built for the calculation of the power distribution characteristics. Moreover, the deformation of the non-uniform elastic membrane of the lens under different pressures is analysed with finite element method (FEM). Results Finally, a prototype of the lens is developed and tested by applying a micro laser displacement sensor, and it is demonstrated that the progressive multifocal lens is feasible. Conclusion A novel liquid progressive multifocal lens with a non-uniform thickness elastic membrane is proposed. From the simulation and experimental investigation, it can be concluded that the proposed liquid lens can realize progressive multifocal through using non-uniform elastic membrane and the power can be adjusted by the pressure which is controlled by the liquid volume filled in the lens

A liquid progressive multifocal lens adjusted by the deformation of a non-uniform elastic membrane due to the variation of liquid pressure

Background: In this paper, a liquid progressive multifocal lens with solid-liquid structure is demonstrated, which mainly consists of two elastic polydimethylsiloxane (PDMS) membranes, a solid substrate and liquid. Methods: To realize the adjustment of the focuses progressively, the thickness of one of the membrane is designed non-uniform. By controlling the liquid pressure working on the membranes, the curvature of the membrane can be changed continuously and the power of the lens can be altered simultaneously. In this paper, the structure and a fabrication method of the lens is introduced, and a power distribution model is built for the calculation of the power distribution characteristics. Moreover, the deformation of the non-uniform elastic membrane of the lens under different pressures is analysed with finite element method (FEM). Results: Finally, a prototype of the lens is developed and tested by applying a micro laser displacement sensor, and it is demonstrated that the progressive multifocal lens is feasible. Conclusion: A novel liquid progressive multifocal lens with a non-uniform thickness elastic membrane is proposed. From the simulation and experimental investigation, it can be concluded that the proposed liquid lens can realize progressive multifocal through using non-uniform elastic membrane and the power can be adjusted by the pressure which is controlled by the liquid volume filled in the lens

Overpressuring Mechanisms in the Yinggehai Basin, South China Sea

Yinggehai Basin is an elongate Cenozoic rift basin on the northwestern margin of the South China Sea continental shelf. Its thick (~17 km) basin fill is characterized by high geothermal gradient and high overpressure. Overpressure associated with nonequilibrium compaction mainly occurs at depths more than 2800 m at the basin center and more than 4000 m at the basin margin because the shallow-buried Neogene and Quaternary strata lack effective seals. This regional overpressure distribution, however, is disrupted at basin center where high overpressure occurs in permeable formations at a depth as shallow as 1400 m on top of a series of deep-seated faults and fractures. We studied the processes and mechanisms of overpressuring via numerical modeling that couples basin filling, sediment compaction, and thermal and pressure fields to approach the origin of the shallow high overpressure. Model results indicated that an increase of fluid volume due to natural-gas generation by organic cracking is not large enough to generate the overpressure because of the limited amount of organic matter. The shallow over-pressure has probably been generated allogenically. Deep open faults have served as vertical hydraulic conduits and channeled the deep high pressure into shallow permeable formations