A Statistical Investigation of the Earthquake Predictions Using LURR

In terms of the spatial scanning of LURR (Load-Unload Response Ratio), we have been predicting the seismic tendency within the next year for the mainland of China from 1995 to 2003. In order to make the quantitative retrospective assessment of LURR metho

A flow cytometer based protocol for quantitative analysis of bloom-forming cyanobacteria (Microcystis) in lake sediments

A quantitative protocol for the rapid analysis of Microcystis cells and colonies in lake sediment was developed using a modified flow cytometer, the CytoSense. For cell enumeration, diluted sediment samples containing Microcystis were processed with sonication to disintegrate colonies into single cells. An optimized procedure suggested that 5 mg dw (dry weight)/mL dilution combined with 200 W x 2 min sonication yielded the highest counting efficiency. Under the optimized determination conditions, the quantification limit of this protocol was 3.3x10(4) cells/g dw. For colony analysis, Microcystis were isolated from the sediment by filtration. Colony lengths measured by flow cytometry were similar to those measured by microscopy for the size range of one single cell to almost 400 mu m in length. Moreover, the relationship between colony size and cell number was determined for three Microcystis species, including Microcystis flos-aquae, M. aeruginosa and M. wessenbergii. Regression formulas were used to calculate the cell numbers in different-sized colonies. The developed protocol was applied to field sediment samples from Lake Taihu. The results indicated the potential and applicability of flow cytometry as a tool for the rapid analysis of benthic Microcystis. This study provided a new capability for the high frequency monitoring of benthic overwintering and population dynamics of this bloom-forming cyanobacterium.A quantitative protocol for the rapid analysis of Microcystis cells and colonies in lake sediment was developed using a modified flow cytometer, the CytoSense. For cell enumeration, diluted sediment samples containing Microcystis were processed with sonication to disintegrate colonies into single cells. An optimized procedure suggested that 5 mg dw (dry weight)/mL dilution combined with 200 W x 2 min sonication yielded the highest counting efficiency. Under the optimized determination conditions, the quantification limit of this protocol was 3.3x10(4) cells/g dw. For colony analysis, Microcystis were isolated from the sediment by filtration. Colony lengths measured by flow cytometry were similar to those measured by microscopy for the size range of one single cell to almost 400 mu m in length. Moreover, the relationship between colony size and cell number was determined for three Microcystis species, including Microcystis flos-aquae, M. aeruginosa and M. wessenbergii. Regression formulas were used to calculate the cell numbers in different-sized colonies. The developed protocol was applied to field sediment samples from Lake Taihu. The results indicated the potential and applicability of flow cytometry as a tool for the rapid analysis of benthic Microcystis. This study provided a new capability for the high frequency monitoring of benthic overwintering and population dynamics of this bloom-forming cyanobacterium

Intentional islanding method based on community detection for distribution networks

Complex network theory is introduced to solve the islanding problem in an emergency of distribution networks. In this study, the authors put forward an intentional islanding method based on community detection. In this method, a new index has been defined called electrical edge betweenness, on the strength of edge betweenness in complex networks, which fuses electrical characteristics with topological features of actual power lines. Based on the index, the Girvan–Newman algorithm is employed to detect the community structure of distribution networks. Through referring to the modularity value (function Q) and coherent generator groups, they can get a reasonable amount and regions of communities. Then the whole distribution network can be partitioned into several self-sustainable islands meeting the stable operation constraints. The effectiveness of the authors’ proposed method is tested on a standard IEEE 118-bus system.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Intelligent Electrical Power Grid

Zum Stand der Entwicklung geistiger Faehigkeiten in der Klassenstufe 3 Kurzbericht zur LSF-3

UuStB Koeln(38)-910106522 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Risk analysis on cascade breaching of the Tangjiashan landslide dam and two smaller downstream landslide dams

The 2008 Mw 7.9 Wenchuan earthquake triggered at least 257 landslide dams, most of which formed in series along rivers. The failure of an upstream dam could cause the failure of dams downstream one after another. The cascade dam breaching may result in sharp increase of flood and more serious damage downstream. This paper aims to analyze the risks on cascade breaching of the Tangjiashan landslide dam and two smaller downstream landslide dams, which were triggered by the Wenchuan earthquake. The paper first simulates the cascade breaching of these three landslide dams. A modified DABA model is applied for this purpose, in which the water-soil interactions are simulated with erosion and shallow water flow theory. A human risk analysis model, named HURAM, is applied to analyze the cascade breach risks of these three dams. Two scenarios, namely, the simulated real case and the case with the highest flood with overlapping effect, will be considered to show the characteristics of the cascade dam breaching risks. It is found that cascading dam breaching is very likely to form multiple-peak floods which may cause multi-round impact to the people downstream. The overlapping effect of cascading dam breaching would amplify the breach flood risk to the people downstream

Influence of liquid-binder ratio on the performance of alkali-activated slag mortar with superabsorbent polymer

The influences of liquid-binder ratio and mixing sequence on the performance of superabsorbent polymer (SAP)-containing alkali-activated slag (AAS) mortar are investigated in this study. It is found that the SAP absorbs much less liquid in upper supernatant of AAS than in water. Mixing SAP with liquid first induces a larger absorption capacity of the SAP than mixing it with solid first. Increasing the liquid-binder ratio improves the flowability but reduces the strength of AAS mortar with SAP. Nonetheless, the strength of internally cured mixtures is higher than that of the reference even with an extra liquid-binder ratio of 0.09. The reason behind lies in the refinement of capillary and gel porosity by internal curing, despite the presence of large voids originated from SAP. The autogenous shrinkage of AAS paste is reduced significantly by the incorporation of SAP but the further mitigating effect of increased liquid-binder ratio is limited.Materials and Environmen

An analysis of acquisition-related subsampling effects on Marchenko focusing, redatuming, and primary estimation

Marchenko methods can retrieve both Green’s functions and focusing functions from single-sided reflection data and a smooth velocity model, as essential components of a redatuming process. Recent studies also show that a modified Marchenko scheme can reconstruct primary-only reflection responses directly from reflection data without requiring a priori model information. To provide insight into the artifacts that arise when input data are not ideally sampled, we study the effects of subsampling in both types of Marchenko methods in 2D earth and data — by analyzing the behaviour of Marchenko-based results on synthetic data subsampled in sources or receivers. We show with a layered model that for Marchenko redatuming, subsampling effects jointly depend on the choice of integration variable and the subsampling dimension, originated from the integrand gather in the multidimensional convolution process. When reflection data are subsampled in a single dimension, integrating on the other yields spatial gaps together with artifacts while integrating on the subsampled dimension produces aliasing artifacts but without spatial gaps. Our complex subsalt model shows the subsampling may lead to very strong artifacts, which can be further complicated by having limited apertures. For Marchenko-based primary estimation (MPE), subsampling below a certain fraction of the fully-sampled data can cause MPE iterations to diverge, which can to some extent be mitigated by using more robust iterative solvers, such as LSQR. Our results, covering redatuming and primary estimation in a range of subsampling scenarios, provide insights that can inform acquisition sampling choices as well as processing parameterization and quality control, e.g., to set up appropriate data filters and scaling to accommodate the effects of dipole fields, or to help ensuring that the data interpolation achieves the desired levels of reconstruction quality that minimize subsampling artifacts in Marchenko-derived fields and images.Applied Geophysics and Petrophysic

Effect of superabsorbent polymer introduction on properties of alkali-activated slag mortar

Internal curing by superabsorbent polymer (SAP) has been applied in alkali-activated slag (AAS) systems by a few previous studies with the purpose to mitigate the autogenous shrinkage. However, the effects of SAP on other properties of AAS have been rarely studied. In this paper, the workability, strength, permeability, and frost resistance of AAS mortar with synthesized SAP are investigated besides the autogenous shrinkage. Two SAP introducing ways (dry mixing and wet mixing) are considered. It is found that the flowability of AAS mortar decreases with the increase of SAP dosage regardless of the introducing way. The strength and permeability increase with the SAP dosage when it is below a certain amount depending on the mixing way. The autogenous shrinkage can be mitigated significantly by the incorporation of SAP and the mitigating effect is more pronounced by wet mixing. The frost resistance becomes better when more SAP is introduced in either way. The mechanisms behind these phenomena are explained based on the characterization results on the reaction kinetics, reaction products and pore structure of the mixtures with SAP.Materials and Environmen

背景音樂對輕度､中度智能不足者輿普通學生在反覆性組合工作之影響

[[abstract]]本研究旨在探討不同背景音樂情境下，三組不同智能程度之受試，於反覆性組合工作 上所表現之生產量與正確率的差異情形。三組受試選自台北市西湖國中普通學生一組 、內湖國中輕度智能不足學生一組、陽明教養院中度智能不足者一組，每組各22名， 合計66名。 本研究採3×4二因子重覆量數實驗設計。其自變項有二：(1) 不同智能組別 (分別普 通學生、輕度智能不足組、中度智能不足組等三組) (2) 不同背景音樂 (分為無音樂 、古典音樂、disco 節奏古典音樂、流行音樂等四類) 。每一組受試皆參與四種背景 音樂的實驗處理，係屬於重覆量數。依變項是計算每一位受試在四類背景音樂的實驗 情境中，所從事的積木組合工作之生產量，及其正確率。特於實驗前及實驗完成後， 分別實施奧卡納手指靈巧測驗，前測所得資料作為共變量，進行二因子重覆量數共變 數分析，後測資料做為評估三組受試視覺動作能力的進步情形。 本研究的主要結果如下： 1.在反覆性組合工作的生產量上，三組受試的成績均達顯著差異。其中以普通學生組 最佳、輕度智障組次之、中度智障組最差。輕度智障組及中度智障組標準差很大，顯 示其個別差異極大。 2.不論是那組受試，在有背景音樂的情境下，其反覆性組合工作之生產量，均高於無 音樂的情境。而音樂類別間則無明顯差異。 3.在反覆性組合工作之正確率上，三組受試的差異，均未達顯著水準。 4.不同組別和不同音樂類別間，不論在生產量或正確率上，均無交互作用存在。 5.在正確率的表現上，只有流行音樂和無音樂間及流行音樂和古典音樂間，具有顯著 差異。 6.不論在何種音樂情境下，生產量與正確率間皆未達顯著相關。不因生產量高，正確 率就低；生產量低，正確率就高。 7.三組受試在視覺動作能力測驗的前測表現上，均具有顯著差異。其中以普通學生組 表現較好，輕度智能不足組次之，中度智能不足組較差。 8.三組受試在視覺動作能力測驗的後表現上，亦均達到顯著差異。仍以普通學生組表 現較好，輕度智能不足組次之，中度智能不足組較差。 9.經過40次實驗後，只有中度智能不足組在前後測表現上達到顯著差異，視覺動作能 力明顯的進步。此種反覆性組合工作，運用在中度智能不足者的識訓，或視覺動作能 力訓練上，頗值得參考。 最後，根據上述之研究發現做進一步的討論，並提出若干建議與本研究之限制，以供 參考。