The Optimization of Power Dispatch for Hydro-thermal Power Systems

AbstractA model in power market for hydro-thermal-nuclear power system has been proposed in this paper. Nuclear units, hydropower units and coal-fired power units are considered to have the renewable energy best used. The model contains two sub-models: Model1 and Model2. Model1 is used to solve the problem of allocating hydro loads and thermal loads, while Model2 is used to solve the problem of optimal power dispatch within hydro units and coal-fired units. Simulation and sensitivity analysis have been done in a case study. The results reveil that the proposed model is correct and the solution approach is effective

Electrified Fracture of Nanotube Films

Strong and conductive carbon nanotube films are ideal candidates for lightning-strike protection. Understanding their failure mechanisms by considering the anisotropic and single-fiber nature is essential to improve performance. Our experimental studies show that the single-layer, nanometer-thick films fail under electrification by crack nucleation and propagation, reminiscent of brittle and ductile fracture of materials under mechanical loads. Sharp and diffuse patterns of fracture are identified in aligned and non-woven films, respectively, signaling the strong effect of material anisotropy that is absent in common engineering materials. The fracture is driven by local Joule heating concentrated at the crack fronts instead of force-induced breakage, which is validated by experimental characterization and simulation results at both continuum and atomistic levels

Dual-Function Conductive Copper Hollow Fibers for Microfiltration and Anti-biofouling in Electrochemical Membrane Bioreactors

Membrane bioreactors (MBRs) with polymeric/ceramic microfiltration (MF) membranes have been commonly used for wastewater treatment today. However, membrane biofouling often results in a dramatically-reduced service life of MF membranes, which limits the application of this technology. In this study, Cu hollow fiber membranes (Cu-HFMs) with low resistivity (104.8–309.8 nΩ·m) and anti-biofouling properties were successfully synthesized. Further analysis demonstrated that Cu-HFMs reduced at 625°C achieved the bimodal pore size distribution of ~1 μm and a porosity of 46%, which enable high N2 permeance (1.56 × 10−5 mol/m2 s pa) and pure water flux (5812 LMH/bar). The Cu-HFMs were further applied as the conductive cathodes, as well as MF membranes, in the electrochemical membrane bioreactor (EMBR) system that was enriched with domestic wastewater at an applied voltage of 0.9 V. Excellent permeate quality (Total suspended solids (TSS) = 11 mg/L) was achieved at a flux of 9.47 LMH after Cu-HFM filtration, with relatively stable transmembrane pressure (TMP) and low Cu2+ dissolvability (<25 μg/L). The anti-biofouling over time was demonstrated by SEM characterization of the rare biofilm formation on the Cu-HFM cathode surface. By using Cu-HFMs in EMBR systems, an effective strategy to control the membrane biofouling is developed in this study

The Effect of Iron Oxide Magnetic Nanoparticles on Smooth Muscle Cells

Recently, magnetic nanoparticles of iron oxide (Fe3O4, γ-Fe2O3) have shown an increasing number of applications in the field of biomedicine, but some questions have been raised about the potential impact of these nanoparticles on the environment and human health. In this work, the three types of magnetic nanoparticles (DMSA-Fe2O3, APTS-Fe2O3, and GLU-Fe2O3) with the same crystal structure, magnetic properties, and size distribution was designed, prepared, and characterized by transmission electronic microscopy, powder X-ray diffraction, zeta potential analyzer, vibrating sample magnetometer, and Fourier transform Infrared spectroscopy. Then, we have investigated the effect of the three types of magnetic nanoparticles (DMSA-Fe2O3, APTS-Fe2O3, and GLU-Fe2O3) on smooth muscle cells (SMCs). Cellular uptake of nanoparticles by SMC displays the dose, the incubation time and surface property dependent patterns. Through the thin section TEM images, we observe that DMSA-Fe2O3is incorporated into the lysosome of SMCs. The magnetic nanoparticles have no inflammation impact, but decrease the viability of SMCs. The other questions about metabolism and other impacts will be the next subject of further studies

MiR-128 Inhibits Tumor Growth and Angiogenesis by Targeting p70S6K1

MicroRNAs are a class of small noncoding RNAs that function as critical gene regulators through targeting mRNAs for translational repression or degradation. In this study, we showed that miR-128 expression levels were decreased in glioma, and identified p70S6K1 as a novel direct target of miR-128. Overexpression of miR-128 suppressed p70S6K1 and its downstream signaling molecules such as HIF-1 and VEGF expression, and attenuated cell proliferation, tumor growth and angiogenesis. Forced expression of p70S6K1 can partly rescue the inhibitory effect of miR-128 in the cells. Taken together, these findings will shed light to the role and mechanism of miR-128 in regulating glioma tumor angiogenesis via miR-128/p70S6K1 axis, and miR-128 may serve as a potential therapeutic target in glioma in the future

Multi-tissue integrative analysis of personal epigenomes

Evaluating the impact of genetic variants on transcriptional regulation is a central goal in biological science that has been constrained by reliance on a single reference genome. To address this, we constructed phased, diploid genomes for four cadaveric donors (using long-read sequencing) and systematically charted noncoding regulatory elements and transcriptional activity across more than 25 tissues from these donors. Integrative analysis revealed over a million variants with allele-specific activity, coordinated, locus-scale allelic imbalances, and structural variants impacting proximal chromatin structure. We relate the personal genome analysis to the ENCODE encyclopedia, annotating allele- and tissue-specific elements that are strongly enriched for variants impacting expression and disease phenotypes. These experimental and statistical approaches, and the corresponding EN-TEx resource, provide a framework for personalized functional genomics

Significant Reduction in the Switching Time of Solid-State Electrochemical Thermal Transistors

Thermal transistors have the remarkable ability to electrochemicallyswitch the thermal conductivity (& kappa;) of an active material. Severalthermal transistors have been reported to control heat flow, but theyare impractical because they use liquid electrolytes. Recently, werealized a solid-state thermal transistor that electrochemically controlsthe & kappa; of SrCoO x (2 & LE; x & LE; 3) using 0.5-mm-thick yttria-stabilized zirconia(YSZ) single crystal substrates as a solid electrolyte at 280 & DEG;C.The applicable electric current is low (50 & mu;A) due to the highelectrical resistivity of YSZ at 280 & DEG;C. Consequently, & kappa;switching is slow (& SIM;3 min). Herein, we aim to reduce the switchingtime by examining several SrCoO x -basedthermal transistors using YSZ substrates with varied thicknesses.The x in SrCoO x is controlledbetween 2 and 3, and the & kappa; switches between 0.97 and 3.86 Wm(-1) K-1. The overall electricalresistance decreases as the YSZ thickness decreases. For a 0.1-mm-thickYSZ substrate, the applicable current increases to 1 mA and the switchingtime is significantly reduced to & SIM;10 s