Improved TARP development based upon mine specific data

The trigger action response plans(TARPs) are inherent to managing the multiple hazards such as: high gas content with multiple coal seams, high spontaneous combustion(sponcom) propensity, heat and ventilation. TARPs aim to provide assurance and guidance when the situation deviates from the original plan or there is a change conditions that could be hazardous. Over the years, learnings from various incidents has continuously required the coal operations to re-visit the TARP trigger values that were based on historic data or based on guidance values from the industry. In most cases, the background to the basis of TARP statistical data, viz., average, maximum, hourly, daily for the monitoring or sampling location is also unknown. Introduction of real-time monitoring devices to monitor the gases and airflows has provided greater understanding of the hazard scenarios and their controls. This paper analyses the carbon monoxide data from operating longwall mines and compares these with the historic trigger values to understand the changes and determine improvement opportunities while setting trigger levels in the TARPs.As an example of setting trigger values, those used in during the sealing of a panel are explored in terms of setting values based upon the sampling location and the level of risk. It is envisaged that the learning's shared herein would further enhance the understanding and management of multiple hazards in Australian coal mines.     

论西部历史文化名城的保护与建设

本文首先提出了历史文化名城的保护作用和保护目的,确定历史文化名城的保护范畴及保护方式,阐述了历史文化名城建设中所面临的实际问题与解决对策.在此基础上,再引伸出西部历史文化名城的特点与风貌,重点对平遥、西安等城市作了较为详细的介绍和分析。文章最后提出了对西部历史文化名城的建设与发展的一些意见和看法.     

Estimating Displacement of Periodic Motion With Inertial Sensors

Inertial sensors, like accelerometers and gyroscopes, are rarely used by themselves to measure displacement. Accuracy of inertial sensors is greatly handicapped by the notorious integration drift, which arises due to numerical integration of the sensors zero bias error. A solution is proposed in this paper to provide drift free estimation of displacement from inertial sensors.     

In vitro Digestibility of Raw Starches Extracted from five Yam (Dioscorea spp.) Species Grown in Jamaica

Starch granules from Round leaf yellow yam, Negro yam, Sweet yam, Bitter yam and Chinese yam grown in Jamaica were isolated and characterized. The amylose content, granular size, crystallinity, and digestibility by α‐amylase were determined. The granules obtained were of three crystalline types. Round leaf yellow yam, Negro yam and Sweet yam were found to be type‐B, while Chinese yam and Bitter yam were type‐C and type‐A, respectively. Round leaf yellow yam had the highest amylose content (26.5%) while Chinese yam had the lowest (11.1%). The granule size varied between 1–3 μm for Chinese yam and 16–42 μm for Round leaf yellow yam. Significant variations in digestibility of the granules were observed. Raw starches from Chinese yam and Bitter yam were the most susceptible to α‐amylase digestion (porcine pancreatic α‐amylase, pH 5.5, 0.02% CaCl₂, 40°C, 24 h) with 21.27 ± 0.01% and 18.11 ± 0.02% degradation, respectively, while Round leaf yellow yam, Negro yam and Sweet yam starches were the least susceptible, with 13.74 ± 0.03%, 14.98 ± 0.08%, and 15.32 ± 0.04% enzymatic degradation, respectively.     

Integration of a particle-based homogenization theory into a general damage-based constitutive model to improve the modelling of void nucleation to coalescence

A novel framework and integration scheme has been developed to implement a secant-based homogenization theory for particle-reinforced plasticity into an existing damage-based constitutive model. In this approach, the material is envisaged as a three-phase composite composed of voids and particles embedded in a ductile matrix. Two successive homogenization theories (damage- and particle-based) are then applied to determine the macro-mechanical response of the material as well as the average stress state within the constituents as a function of the particle shape, composition and volume fraction. By identifying the stress state within the particles and the matrix, void nucleation can be accurately represented and the void growth and coalescence models are improved through knowledge of the stress state within the matrix. The performance of this loosely coupled model is analytically evaluated using idealized composite materials that contain inclusions of various shapes to elucidate the influence of the inclusion morphology on damage evolution and coalescence. The present work provides an efficient, albeit approximate, algorithm that can be readily included into existing damage-based constitutive models to improve their predictions of damage evolution, particularly related to void nucleation.      

Growth of Cu2ZnSnS4 thin films on Si (100) substrates by multisource evaporation

Cu₂ZnSnS₄ films were grown on Si (100) by vacuum evaporation using elemental Cu, Sn, S and binary ZnS as sources. X-ray diffraction patterns of films grown at different substrate temperatures indicated that polycrystalline growth was suppressed and the orientational growths were relatively induced in a film grown at higher temperatures. Tetragonal structure of Cu₂ZnSnS₄ films was confirmed by studying RHEED patterns. The existence of c-axis ([001] direction) growth, two kinds of a-axis (〈100〉 direction) growth and four kinds of {112} twins which can be classified as two symmetrical pairs is proposed. Broad emissions at around 1.45 eV and 1.31 eV were observed in the photoluminescence spectrum measured at 13 K.     

Strategies for Planned Project Acceleration

Departments of transportation in the United States are under increasing pressure to accelerate projects to meet user-defined constraints and reduce the inconvenience to the traveling public. Although there is information about acceleration projects in other industries, there has been little specifically aimed at highway projects. A domestic scan sponsored by the National Cooperative Highway Research Program was tasked with providing information in this area. The objective of this paper is to synthesize the resulting information into fundamentals that support successful planned accelerated highway project delivery. Case studies of how departments of transportation successfully accelerated the construction of four very different projects in California, Florida, and Texas serve as the basis for identifying these fundamentals. The fundamentals include upfront and detailed planning, designs that facilitate accelerated construction, a collaborative environment for project stakeholders, and incentives and disincentives to motivate construction contractors.     

Evolution and kinetics of monosaccharides,disaccharides and α-galactosides during germination of lentils

The effect of light and seed rinsing during the germination of lentil seeds (Lens culinaris var. vulgaris, cultivar Magda-20) on the level of monosaccharides, disaccharides and α-galactosides (raffinose, ciceritol and stachyose) was investigated. The total soluble sugar content corresponded to about 9% of the mature seed weight, about 65% of which was α-galactosides. Germination brought about a large decrease in α-galactosides: 18% to 40% losses after 3 days and 100% after 6 days. However, glucose, which was not detected in ungerminated seeds, as well as fructose and sucrose gradually increased during germination. The content of α-galactosides decreased more rapidly when germinating seeds were given 6 h light per day, but under these conditions there was also a major reduction in the levels of fructose, glucose and sucrose. Seeds rinsed daily showed a greater reduction of α-galactosides and an increase in the levels of fructose, glucose and sucrose. When seeds were germinated for 10 days in the dark with daily rinsing, the content of α-galactosides decreased gradually during the first 4 days and they were not detected after 6 days. Under these conditions, fructose, glucose and sucrose, which represented about 3% of the mature seed weight, started increasing after day 2 and represented more than 13% of the germinated seed dry weight after 10 days.     

Improved cure optimization in pultrusion with pre-heating and die-cooler temperature

Optimization studies are performed on the pultrusion of a thermosetting composite. The three-dimensional finite element/nodal control volume procedure developed for simulation and optimization of the process is employed for this purpose. The aim of optimization is to achieve the desired degree of cure with minimum local variations across the pultrudate cross-section. The die-heating environment is optimized for a few cases with different initial temperatures for a glass/epoxy wet preform and for the cooler installed within the pultrusion die near its entrance. The role of these temperature parameters in moderating the optimization constraints is examined. Simultaneous optimization of die-heater temperatures and pull-speed is also considered. It is observed that the temperature overshoot within the composite pultrudate can be reduced and better optimization results can be achieved by a proper choice of a pre-die temperature for the composite and the die-cooler temperature.