Micromechanical Behaviour in Shearing of Reproduced Flat LBS Grains with Strong and Weak Artificial Bonds

The shearing behaviour of reproduced flat LBS grains artificially bonded with ordinary Portland cement (OPC) and plaster of Paris (PP) was examined using micromechanical experiments. Monotonic shearing tests showed a distinct variation in the load–displacement relationship at low, medium and high normal loads, and a nonlinear shear strength envelope was proposed. For OPC-bonded sand grains, a brittle–ductile transition at 20–30 N normal load was observed and three breakage mechanisms in shearing (chipping, shear cracks and crushing) were distinguished in accordance with the changes in the load–displacement curves. OPC-bonded sands showed a predominant dilation at lower normal loads, whereas PP-bonded sands were highly compressive. Based on previously published works using element-scale tests, a new mechanism for dilation under micromechanical testing was proposed in the study. Cyclic shearing tests were conducted on OPC-bonded sands, and the effects of increased displacement amplitude and normal load were highlighted

Superabsorbent polymers (SAP) enhance efficient and eco-friendly production of corn (Zea mays L.) in drought affected areas of northern China

In arid and semiarid regions of northern China, there is an increasing interest in using reduced rate of chemical fertilizer along with water-saving superabsorbent polymer (SAP) for field crop production. The objective was to evaluate the effectiveness of different rates of SAP (low, 0.75; medium, 11.3 and high, 15.0 kg ha-1) against half amount of conventional standard rate of chemical fertilizer for summer corn (Zea mays L.) production in a drought-affected field of northern China. Corn yield increased following SAP application by 11.2% under low 18.8% under medium and 29.2% under high rate with only half amount (150 kg ha-1) of fertilizer compared with control plants, which received conventional standard fertilizer rate (300 kg ha-1). At the same time plant height, stem diameter, leaf area, biomass accumulation and relative water content as well as protein and sugar contents in the grain also increased significantly following SAP treatments. The optimum application of SAP in the study area would be 15 kg ha-1 as it brings progressive increase in corn growth and also maintain proper nutrients balance in the soil after harvest. Other rates are not sufficient to maintain proper plant growth or soil nutrient balance against half fertilizer. We suggest that, the application of SAP at 15 kg ha-1 plus only half the amount of conventional fertilizer rate (150 kg ha-1) would be a more appropriate practice for sustainable corn production under arid and semiarid conditions of northern China or the areas with similar ecologies.Key words: Corn, drought stress, fertilizer use efficiency, northern China, superabsorbent polymer

Statistical GGP Game Decomposition

International audienceThis paper presents a statistical approach for the decomposition of games in the General Game Playing framework. General game players can drastically decrease game search cost if they hold a decomposed version of the game. Previous works on decomposition rely on syn-tactical structures, which can be missing from the game description, or on the disjunctive normal form of the rules, which is very costly to compute. We offer an approach to decompose single or multi-player games which can handle the different classes of compound games described in Game Description Language (parallel games, serial games, multiple games). Our method is based on a statistical analysis of relations between actions and fluents. We tested our program on 597 games. Given a timeout of 1 hour and few playouts (1k), our method successfully provides an expert-like decomposition for 521 of them. With a 1 minute timeout and 5k playouts, it provides a decomposition for 434 of them

Application of Deep Learning Long Short-Term Memory in Energy Demand Forecasting

The smart metering infrastructure has changed how electricity is measured in both residential and industrial application. The large amount of data collected by smart meter per day provides a huge potential for analytics to support the operation of a smart grid, an example of which is energy demand forecasting. Short term energy forecasting can be used by utilities to assess if any forecasted peak energy demand would have an adverse effect on the power system transmission and distribution infrastructure. It can also help in load scheduling and demand side management. Many techniques have been proposed to forecast time series including Support Vector Machine, Artificial Neural Network and Deep Learning. In this work we use Long Short Term Memory architecture to forecast 3-day ahead energy demand across each month in the year. The results show that 3-day ahead demand can be accurately forecasted with a Mean Absolute Percentage Error of 3.15%. In addition to that, the paper proposes way to quantify the time as a feature to be used in the training phase which is shown to affect the network performance

Adsorption and Dissociation of a Bicyclic Tertiary Diamine, Triethylenediamine, on a Si(100)-2 x 1 Surface

This study investigates the adsorption and thermal transformations of a bicyclic tertiary amine, triethylenediamine, on the clean Si(100)-2 × 1 surface. Below room temperature, triethylenediamine adsorption leads to the formation of a strong dative bond between one of the nitrogen atoms of this compound and the silicon surface. In contrast to previously studied amines, the datively adsorbed triethylenediamine features a second tertiary amine entity that is not bonded to the surface, with a lone pair orbital that is directed away from the surface and is available for further reactions. The thermal chemistry and electronic properties of triethylenediamine on silicon are studied using thermal desorption spectroscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. Near-edge X-ray absorption fine structure measurements are utilized to clarify the geometry of the adsorbates at room temperature. Density functional theory calculations are used to describe the binding geometry and electronic properties of the resulting surface species and the likely reaction paths at elevated temperatures

The Search for Higher TcT_c in Houston

It is a great pleasure to be invited to join the chorus on this auspicious occasion to celebrate Professor K. Alex Mueller's 90th birthday by Professors Annette Bussman-Holder, Hugo Keller, and Antonio Bianconi. As a student in high temperature superconductivity, I am forever grateful to Professor Alex Mueller and Dr. Georg Bednorz "for their important breakthrough in the discovery of superconductivity in the ceramic materials" in 1986 as described in the citation of their 1987 Nobel Prize in Physics. It is this breakthrough discovery that has ushered in the explosion of research activities in high temperature superconductivity (HTS) and has provided immense excitement in HTS science and technology in the ensuing decades till now. Alex has not been resting on his laurels and has continued to search for the origin of the unusual high temperature superconductivity in cuprates.Comment: Dedicated to Alex Mueller, whose "important breakthrough in the discovery of superconductivity in ceramic materials" in 1986 has changed the world of superconductivit

First report of Wiwaxia from the Cambrian Chengjiang Lagerstätte

AbstractThe robust spines and sclerites of the early to middle Cambrian ‘mollusc’ Wiwaxia are ubiquitous in suitably preserved deposits, but are strikingly absent from the Chengjiang Lagerstätte (Cambrian Stage 3, Yunnan Province, SW China). Here we provide the first record of Wiwaxia sclerites from this rich deposit, extending the record of the genus to the earliest Cambrian Series 2. This reinforces the cosmopolitan distribution of this iconic Cambrian lophotrochozoan and demonstrates the strong faunal continuity that unites distant Cambrian Lagerstätten.Research was supported by the Chinese Academy of Sciences (KZZD-EW-02-2); the National Basic Research Program of China (2013CB835006); the National Natural Science Foundation of China (41472012); the Natural Science Foundation of Jiangsu Province (BK2012893); and Clare College, Cambridge.This is the accepted manuscript. The final version is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9545141&fileId=S0016756814000648

GT2003-38568 MODELING AND COST OPTIMIZATION OF COMBINED CYCLE HEAT RECOVERY GENERATOR SYSTEMS

ABSTRACT The combined cycle power plant is made up of three major systems, the gas turbine engine, the heat recovery steam generator and the steam turbine. Of the major systems the gas turbine engine is a fixed design offered by a manufacturer, and the steam turbine is also a fairly standard design available from a manufacturer, but it may be somewhat customized for the project. In contrast, the heat recovery steam generator (HRSG) offers many different design options, and its design is highly customized and integrated with the steam turbine. The objective of this project is to parametrically investigate the design and cost of the HRSG system, and to demonstrate the impact on the overall cost of electricity (COE) of a combined cycle power plant. There are numerous design parameters that can affect the size and complexity of the HRSG, and it is the plan for the project to identify all the important parameters and to evaluate each. For this study, the design parameter chosen for evaluation is the exhaust gas pressure drop across the HRSG. This parameter affects the performance of both the gas turbine and steam turbine and the size of the heat recovery unit. Single-pressure, two-pressure and three-pressure HRSGs are all investigated, with the tradeoffs between design point size, performance and cost evaluated for each system. A genetic algorithm is used in the design optimization process to minimize the investment cost of the HSRG. Several system level metrics are employed to evaluate a design. They are gas turbine net power, steam turbine net power, fuel consumption of the power plant, net cycle efficiency of the power plant, HRSG investment cost, total investment cost of the power plant and the operating cost measured by the cost of electricity (COE). The impacts of HRSG exhaust gas pressure drop and system complexity on these system level metrics are investigated

Water footprint of Jing-Jin-Ji urban agglomeration in China

A rapidly expanding economy and increasing water demand for agricultural and industrial production is placing enormous stress on water quantity and the aquatic environment in Northern China, especially the so-called Jing-Jin-Ji (Beijing-Tianjin-Hebei) urban agglomeration, home to over 110 million people producing 10% of China's overall GDP. Several studies have focused on energy consumption, air pollution, CO₂ emissions and regional blue water footprint (WF) following release of the Jing-Jin-Ji Integration Strategy by the China government in 2013. However, a comprehensive assessment distinguishing blue, green and grey WF amongst different industrial sectors, ascertaining how WF transfers internally and beyond the region and final demand consumption is not available. We consider this to be crucial in understanding and addressing the deteriorating water situation in the Jing-Jin-Ji. In this study, we quantified the WF and virtual water flow on a sectoral basis for the year 2010 through coupling the multi-regional input-output model (MRIO) with WF assessment. The results showed that Beijing and Tianjin are net importers of green, blue and grey water from Hebei and other China provinces to support their needs. Conversely, Hebei exports all WF colors to Beijing, Tianjin and other provinces in China, and more than 60% of WF is transferred as virtual water. For the overall Jing-Jin-Ji region a small amount of blue water (2086 million m³) is exported, but huge amounts of green water (15,573 million m³) and grey water (30,620 million m³) are outsourced. A “Virtual Water Strategy” is one measure which could alleviate water stress at the regional scale, with consideration of financial compensation from water receiving regions made to water supplying regions in the context of achieving water management targets. We also found that physical water transfer to Jing-Jin-Ji could not balance virtual blue water exports, not to mention compensating for internal water consumption. Our research suggests that a continuation of an export-based economic development model will worsen Hebei's water stress. Reducing the dependency of Hebei's sectoral economy on export of water intensive and low value added agricultural products may be one strategy to reduce the pressure on regional water resources. In addition, the Beijing-Tianjin-Hebei Integration Strategy drives industrial transfer from Beijing to Hebei resulting in the transfer of enterprises with low water utilization efficiency and producing heavy pollution. As a result, the government should consider incentivizing corporations to adopt technologies that reduce water consumption and pollution