A study on cavitation erosion behavior of AlSi10Mg fabricated by selective laser melting (SLM)

Cavitation erosion causes serious problems for hydraulic machinery. Selective laser melting (SLM), is a type of additive manufacturing that can produce metal parts directly and it has begun to be used in various industrial settings. However, the erosion properties of the SLM processed parts have only rarely been reported. The paper addresses the cavitation erosion behavior of AlSi10Mg samples fabricated by SLM at different laser scanning speeds. A wrought sample was also tested to provide a basis for comparison. Sample hardness and microstructure were investigated. Results showed the cavitation erosion behaviors of SLM samples to differ greatly from that of the wrought sample. The erosion rate of SLM samples was found to peak in the first 30 s. This was accompanied by the removal of particles inside pores. After peaking, the erosion rate of the SLM samples decreased significantly. SLM samples showed an extremely low erosion rate entering the steady-state period. Large, deep craters which were common wear marks on the wrought sample, were not present on the SLM samples. Different scanning speeds resulted in different max erosion rates

Extreme Precipitation Estimation with Typhoon Morakot Using Frequency and Spatial Analysis

Typhoon Morakot lashed Taiwan and produced copious amounts of precipitation in 2009. From the point view of hydrological statistics, the impact of the precipitation from typhoon Morakot using a frequency analysis can be analyzed and discussed. The frequency curve, which was fitted mathematically to historical observed data, can be used to estimate the probability of exceedance for runoff events of a certain magnitude. The study integrates frequency analysis and spatial analysis to assess the effect of Typhoon Morakot event on rainfall frequency in the Gaoping River basin of southern Taiwan. First, extreme rainfall data are collected at sixteen stations for durations of 1, 3, 6, 12, and 24 hours and then an appropriate probability distribution was selected to analyze the impact of the extreme hydrological event. Spatial rainfall patterns for a return period of 200-yr with 24-hr duration with and without Typhoon Morakot are estimated. Results show that the rainfall amount is significantly different with long duration with and without the event for frequency analysis. Furthermore, spatial analysis shows that extreme rainfall for a return period of 200-yr is highly dependent on topography and is smaller in the southwest than that in the east. The results not only demonstrate the distinct effect of Typhoon Morakot on frequency analysis, but also could provide reference in future planning of hydrological engineering

Rechecking the Centrality-Lethality Rule in the Scope of Protein Subcellular Localization Interaction Networks

Essential proteins are indispensable for living organisms to maintain life activities and play important roles in the studies of pathology, synthetic biology, and drug design. Therefore, besides experiment methods, many computational methods are proposed to identify essential proteins. Based on the centrality-lethality rule, various centrality methods are employed to predict essential proteins in a Protein-protein Interaction Network (PIN). However, neglecting the temporal and spatial features of protein-protein interactions, the centrality scores calculated by centrality methods are not effective enough for measuring the essentiality of proteins in a PIN. Moreover, many methods, which overfit with the features of essential proteins for one species, may perform poor for other species. In this paper, we demonstrate that the centrality-lethality rule also exists in Protein Subcellular Localization Interaction Networks (PSLINs). To do this, a method based on Localization Specificity for Essential protein Detection (LSED), was proposed, which can be combined with any centrality method for calculating the improved centrality scores by taking into consideration PSLINs in which proteins play their roles. In this study, LSED was combined with eight centrality methods separately to calculate Localization-specific Centrality Scores (LCSs) for proteins based on the PSLINs of four species (Saccharomyces cerevisiae, Homo sapiens, Mus musculus and Drosophila melanogaster). Compared to the proteins with high centrality scores measured from the global PINs, more proteins with high LCSs measured from PSLINs are essential. It indicates that proteins with high LCSs measured from PSLINs are more likely to be essential and the performance of centrality methods can be improved by LSED. Furthermore, LSED provides a wide applicable prediction model to identify essential proteins for different species

1,2-Bis(1H-tetra­zol-5-yl)benzene dihydrate

The asymmetric unit of the title compound, C8H6N8·2H2O, contains one half-mol­ecule, with the benzene ring on a centre of symmetry, and two uncoordinated water mol­ecules. The benzene ring is oriented at a dihedral angle of 34.43 (12)° with respect to the tetra­zole ring. Strong O—H⋯N hydrogen bonds link the water mol­ecules to the N atoms of the tetra­zole ring. In the crystal structure, strong inter­molecular O—H⋯O and O—H⋯N hydrogen bonds link the mol­ecules into a network. One of the water H atoms is disordered over two positions and was refined with occupancies of 0.50

Topological superradiance in a degenerate Fermi gas

We predict the existence of a topological superradiant state in a two-component degenerate Fermi gas in a cavity. The superradiant light generation in the transversely driven cavity mode induces a cavity-assisted spin-orbit coupling in the system and opens a bulk gap at half-filling. This mechanism can simultaneously drive a topological phase transition in the system, yielding a topological superradiant phase. We map out the steady-state phase diagram of the system in the presence of an effective Zeeman field, and identify a critical quadracritical point beyond which the topological and the conventional superraidiant phase boundaries separate. We also propose to detect the topological phase transitions based on the unique signatures in the momentum-space density distribution.Comment: 12 pages, 8 figures, latest versio

Antioxidant activities of protein hydrolysates obtained from the housefly larvae

The housefly is an important resource insect and the housefly larvae are ideal source of food additives. The housefly larvae protein hydrolysates were obtained by enzymatic hydrolysis by alcalase and neutral proteinase. Their antioxidant activities were investigated, including the superoxide and hydroxyl radicalscavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and metal chelating activity. The antioxidant activities of both hydrolysates increased with their increasing concentrations. The alcalase hydrolysate (AH) showed higher scavenging activities against hydroxyl radical and superoxide anion radical at low concentrations and higher metal-chelating activity than the neutral proteinase hydrolysate (NPH). The NPH exhibited higher scavenging activity against DPPH free radical and higher reducing power than the AH. Both hydrolysates showed more than 50% superoxide anion radical-scavenging activity at 10 μg/mL. These results indicate that both housefly larvae protein hydrolysates display high antioxidant activities and they could serve as potential natural antioxidant food additives