Sustainability Commons^™

A New Instability Criterion Of Double Strength Reduction Method For Slope, Fang Hongwei, Wu Jianxun, Hou Zhenkun

Coal Geology & Exploration

Based on the slip line field theory(SLFT), a new instability criterion of strength reduction method with double re-duction factors for homogeneous slopes was proposed. It is judged that the slope is in the limit equilibrium state when the slope contour under limit equilibrium state(abbreviated as the critical slope contour) calculated by the SLFT intersects with the slope line at the toe. The critical curve was constructed in the plane of the inverse of the double reduction factors, and the comprehensive safety factor was derived. The slope calculation results show that three relative position relationships between the initial point and the …

The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei

Coal Geology & Exploration

The coal seam is a typical thin bed characterized by much lower elastic impedance than that of the surrounding rock. Coal seam has viscoelasticity and velocity anisotropy and its reflection amplitude changes with frequency. In order to analyze the effect of viscoelasticity and velocity anisotropy on seismic responses of a thin bed, this paper aims at a thin-bed model with strong impedance contrast and simulates seismic responses under three different assumptions, elastic and velocity isotropy, viscoelastic and velocity isotropy, and viscoelastic and velocity anisotropy, through numerical simulation method based on wave equations. Comparison of these seismic reflections shows that the …

Acquisition Platform Of Frequency Domain Ip Signal, Fu Guohong, Zhang Qianfeng, Cheng Hui, Xie Tiancai

Coal Geology & Exploration

In order to improve the versatility of the induced polarization(IP) signal receiver of traditional frequency domain, a signal acquisition platform was designed, which can acquire and process IP signals of frequency domain such as variable-frequency signals, dual-frequency IP signals, and pseudo-random multi-frequency IP signals and so on. Hardware circuits were established based on STM32 to execute low-pass filtering, program-controlled amplification, analog-to-digital conversion, and data communication. The host computer was developed in LabVIEW to achieve parameter settings, digital filtering, spectrum analysis, amplitude measurement and calculation to obtain target parameters such as PFE, and has waveform display and playback, data storage and …

The Influence Of Grounding Grid On Electromagnetic Detection Of Goaf, Xu Xing, Weng Ling, Li Shiqiang, Liu Guoqiang

Coal Geology & Exploration

The existence of underground goaf can easily cause tilting and settlement of power towers, which is a major hidden factor in the safe and stable operation of power grid. To detect the mine goaf under the power transmission corridor is of great significance. When there is a grounding grid in the detection area, the grounding grid will have certain influence on the measured value. In this paper, the detection of mine goaf in the presence of a grounding grid is presented. Based on the theoretical analysis, the mathematical model is built, and the simulation model is conducted. The influence of …

Design And Application Of Multi-Section Bundled Bag Wire-Line Coring Drilling Tools, Han Yi, Zhang Shaohe, Bai Rui, Sun Pinghe, Shu Biao, Cao Han, Zhang Xinxin

Coal Geology & Exploration

Because the existing conventional wire-line coring drilling tool lacks the water-proof and core-protecting device, the broken core is easily eroded when the core is drilled in a complicated layer such as loose, weak, broken layers and the core is easy to fall off during the lifting process, so that the coring rate and core quality are not up to the design requirements, and even core can not be taken to. In response to the above problems, a bag-type wire-line coring drilling tool was designed. The drill adds a multi-section bundled bag assembly structure to the conventional wire-line coring drilling tool …

Study On Local Volume Breakage Of Diamond-Impregnated Bit, Sun Jiwei, Shen Lina, Yang Gansheng, Ye Jichao

Coal Geology & Exploration

To solve the problem of high energy consumption and slow drilling speed of impregnated diamond drill in hard rock, the method of volume crushing to improve drilling efficiency was put forward. In order to study the crushed volume of impregnated diamond bit in hard rock, firstly, an test of single diamond pressed into rock was designed. According to the experimental data, the first partial broken volume when single diamond was pressed into rock was the volume breakage type of impregnated diamond bit. Then the mathematical model of optimal drilling pressure and speed in first partial broken volume was deduced. By …

Evaluation Technology For Key Monitoring Area Of Early Warning Of Water Inrush From The Floor Of Working Face In Coal Mine, Liu Demin, Yin Shangxian, Lian Huiqing

Coal Geology & Exploration

Accurately delineating the key monitoring areas for water inrush warning of the floor of working face in coal mine and realizing the spatial matching of the monitoring position of the early warning system and the location of potential water inrush points are one of the urgent problems to be solved in the warning of water inrush from the floor of working face in coal mine. In order to study the evaluation technology for key monitoring area of water inrush warning of the floor of working face in coal mine, hydrogeological analysis, GIS spatial analysis and ANN prediction were used to …

Spatial Distribution And Formation Of Groundwater Hydrochemistry In Huainan Coalfield, Wang Zitao, Liu Qimeng, Liu Yu

Coal Geology & Exploration

In order to study the spatial distribution of groundwater in Huainan coalfield and the intensity of various hydrochemical actions, the coalfied is divided into the northern district with thicker loose beds and the southern district with thinner loose beds. Hydrochemical test data of main water-inrushing aquifers in 16 mines in these two areas were collected and statistically analyzed, ion combination method and Gibbs diagram were used to study the groundwater hydrochemical characteristics of each aquifer in north and south areas. The results indicate that TDS of aquifer is positively correlated with the burial thickness of unconsolidated formation. With the increase …

Influence Of The Freezing-Thawing Cycles On Soil-Water Characteristics Of Soil In Open-Pit Mine Dumping Sites, Wang Xuedong, Li Shiyu, Sun Yanfeng, Ye Guo

Coal Geology & Exploration

In order to study the unsaturated soil-water characteristics of soil under freezing-thawing cycles, the soil in Yuanbaoshan open-pit mine dumping site was selected as the research object. The variation of matrix suction and structure of soil under different water content after different freezing-thawing cycles was studied. The results show that during the same freezing-thawing cycles, the matrix suction increases with the decrease of water content, and the range increases gradually. The soil-water characteristic curve can be divided into sensitive stage, sub-sensitive stage and insensitive stage. With the increase of freezing-thawing cycles, the curvature of soil-water characteristic curve increases first and …

Similar Model Test And Mechanical Analysis Of Fault Structure, Song Yanqi, Wang Shilei, Sun Chuan, Hao Liangjun

Coal Geology & Exploration

The pre-existing fault specimens were made to confirm the actual stratum mechanical properties based on the similarity theory. Then the mechanism of failure mode of pre-existing fault was analyzed under the crack tip stress field theory. The results show that with the increase of load, the microcracks develop gradually and propagate, and the propagation path tends to the loading direction. In the process of crack propagation, multiple branch paths are generated, and then the cracks merge with each other to destroy the specimen. The stress field theory can be used to determine the newly generated fracture direction, which is consistent …

Fractal Theory-Based Investigation Of The Optimal Interval Of Minimum Pore Radius Of Sandstone, Xu Lulu, Dong Shuning, Dai Zhenxue, Xu Bin, Yin Shangxian, Zhou Yan, Chen Junjun

Coal Geology & Exploration

Permeability is a main parameter for evaluation of water conductivity of porous media, and it is a macroscopic feature of micro-pore structure of water-conducting media. To obtain the geometry parameters of microscopic pores, we performed scanning electron microscopy(SEM) on sandstone samples. The image processing techniques were also applied in calculation of different statistical parameters(e.g., fractal dimensions) and geometrical parameters. Then, fractal theory was introduced to investigate the influence of micro pore structure on permeability. At the same time, the minimum pore radius r_min interval acting on the seepage was obtained by the measured permeability values. This interval can be …

Stability Of Cement-Based Grouting Slurry And Test Of Its Bleeding Law, Xu Bin, Dong Shuning, Xu Lulu, Zhou Yan, Chen Junjun, Dai Zhenxue, Wang Hao

Coal Geology & Exploration

To better understand the stability performance and bleeding property of cement-based grouting slurry, a new test device was improved to get the separated-water thickness value of slurry samples at every time, and these samples were made and sorted according to the certain proportion of the water-solid ratio(0.6:1 to 3:1), fly ash content(0-90%) and sodium silicate content(0-12%). The growth theory for separated-water thickness was introduced, and the growth curves for all formulations were plotted. The slurry stability measurement method was classified, and the equivalence relation between the direct measurement method of slurry stability and the indirect measurement method was verified. The …

Experimental Study Of Three-Component Down-Hole Tem For Detecting Water-Filled Goaf, Yao Weihua, Wang Peng, Li Mingxing, Su Chao, Cheng Siyuan

Coal Geology & Exploration

The borehole geophysical prospecting method is a research hotspot in recent years. Considering that the down-hole transient electromagnetic method used in metal mines has the characteristics of long radial detection distance and less susceptible to surface electromagnetic interference, it is applied to the exploration of water-filled goaf in coal mines. Three-dimensional finite-difference time-domain(FDTD) algorithm is used to simulate the total field response and abnormal response of the goaf model with different orientations of boreholes. The total field three-component could reflect the water-filled goaf obviously, and the abnormal field three-component shape combination can distinguish the azimuth of the abnormal body. Based …

Fractal Characteristics Of Pores And Microfractures Of Coals With Different Structure And Their Effect On Permeability, Ye Zhenni, Hou Enke, Duan Zhonghui, Wen Qiang, Huang Meitao, He Dan

Coal Geology & Exploration

The characteristics of pores and fractures in coal are the basis to study permeability. In this study, the micro-pores and fractures of coal samples with different structure taken from Guojiahe coal mine were analyzed using mercury injection experiment and scanning electron microscope. The micro-pores and fractures of intact coal and cataclastic coal samples were quantitatively analyzed by using Menger sponge and box-counting dimension. The comprehensive fractal dimension was calculated by pore volume weights. Based on fractal theory, the relationship between fractal dimension of coal samples and coal permeability have been discussed. The results show that brittle deformation adds complexity of …

The Discovery And Geological Significance Of Coal-Formed Graphite In Chongyi Coal Mine In Jiangxi Province, Li Yang, Wang Lu, Cao Daiyong, Du Xin, Zhao Meng, Liu Liming, Wei Yingchun

Coal Geology & Exploration

In order to study the characteristics of coal-formed graphite in Chongyi mine, Jiangxi Province, the coal in Laoshan Section of Upper Permian Longtan Formation in Chongyi mining area was tested and analyzed by means of optical microscope, X-ray diffraction(XRD), Raman spectroscopy and HRTED. The test results showed that the graphitization maceral could be observed under the optical microscope. The XRD diffraction pattern showed a graphite diffraction peak of d₀₀₂, and the Raman spectrum showed a characteristic peak of graphite(G peak) with sharp peak shape. Multilayer ordered structure of carbon layer was observed by high resolution transmission electron microscope, …

Evaluation Method Of Compressibility Of Shale Gas Reservoir In Consideration Of The Influence Of Fracture Toughness, Zhang Chenqing, Xu Jiang, Peng Shoujian, Yan Fazhi, Wu Bin, Yue Yuqing

Coal Geology & Exploration

Compressibility is an important basis for measuring the response of shale gas reservoirs to hydraulic fracturing. Currently, the brittleness index commonly used for shale compressibility has been evaluated. However, in practice, there are problems in which the brittleness index is similar and the actual fracturing effect is far different. In order to make up for the lack of brittleness index for the evaluation of compressibility of shale gas reservoirs, this study incorporated critical mechanical energy release rate in consideration of the influence of fracture toughness, and defined the average critical mechanical energy release rate of the integrated modes I and …

Test Of The Influence Of Dynamic Water Grouting Diffusion Radius Of Fractures In Rock, Gu Shuancheng, Sun Guanlin, Su Peili, Li Jinhua

Coal Geology & Exploration

Water-cement ratio and grouting pressure are the key factors in the design of hydrodynamic grouting. In this paper, based on the self-designed simulated fissure hydrodynamic grouting indoor test platform, the dynamic water grouting test was carried out, the diffusion mode of the slurry in fractures was discussed. The relationship among the diffusion radius of pure cement slurry, the grouting pressure and water-cement ratio was analyzed. The experimental results were verified by computational fluid dynamics software. The results show that the diffusion mode of the slurry is partition diffusion. When the grouting pressure is constant, the diffusion radius is inversely proportional …

Lbfgs Csamt 1d Inversion Of Limited Memory Based On Boundary Constraint And Its Application, Tang Chuanzhang, Cheng Jianzhong, Yan Liangjun, Feng Guangye, Zhou Lei, Xu Fengjiao

Coal Geology & Exploration

CSAMT is characterized by time-consuming calculation and low accuracy. The conventional inversion method has simple boundary processing, needs big memory, it is difficult to have accurate search direction, influencing severely the effect of inversion. In order to achieve rapid and high-precision forward modeling of CSAMT, to improve the boundary processing method, to reduce memory usage, to optimize the searching direction to reduce the times of iterative inversion, LBFGS CSAMT 1D inversion method based on boundary constraint and limited memory was proposed. Firstly in CSAMT forward modeling, double-precision and parallel algorithm was adopted, realizing rapid and high-precision calculation of the horizontal …

Calibration And Experiment Of Mine Electromagnetic Lwd Gamma Logging Tool, Wang Xiaolong, Jiang Bici, Wang Kaibin

Coal Geology & Exploration

In order to effectively identify coal seam, roof and floor, mine electromagnetic LWD gamma logging tool was developed for directional drilling in coal mine. The calibration coefficient of the instrument can be obtained by natural gamma logging scale, and various measurement curves of mine electromagnetic LWD gamma logging tool can be obtained by standard well test and crossing borehole test in coal mine. Through comparing with the gamma curve of standard well and analyzing the geological data of the crossing borehole, the measurement result accuracy of mine electromagnetic LWD gamma logging tool is verified. The application test in underground coal …

Development Of Impact Screw Motor, Wang Siyi, Li Quanxin, Liu Jianlin, Zhao Jiangpeng, Yang Dongdong

Coal Geology & Exploration

Aiming at the problems of low efficiency and high consumption of bits and drilling tools in drilling hard rock with conventional single bend screw motor, an impact screw motor is developed by adding an impact mechanism between the universal shaft of a common screw motor and the drill bit. The impact screw motor has dual functions of impact and orientation. The structure and the working principle of impact mechanism, the design of key components and the characteristics of the impact screw motor are introduced. Laboratory tests were carried out on the φ89 mm impact mechanism, and the peak impact …

Investing In The New Blue Economy: The Changing Role Of International Development Organizations In Catalyzing Private Sector Investment In Support Of Regional Strategic Action Programmes For The Sustainable Development Of Coasts And Oceans, Ryan Whisnant, Veerle Vandeweerd

Journal of Ocean and Coastal Economics

Over the last 20 years, governments sharing common coastal and ocean ecosystems have developed and agreed on concrete regional action programs to stop and, in some cases, reverse a trend of deteriorating coastal and ocean resources. Implementation of these action programs requires significant investments by the public and private sectors alike, with the potential for substantial economic growth and enhanced social well-being. For this to happen, new institutional arrangements, technologies, and financial vehicles and asset classes are needed to mainstream innovative “blue economy” projects that have the potential to transition economies and communities to more sustainable development paths.

This paper …

High Functional Diversity Of Contaminated Soils From Liberty State Park, Nina M. Goodey

Sustainability Seminar Series

Urban brownfields present an opportunity to study the functioning of degraded ecosystems. We investigated the soils of Liberty State Park in Jersey City, New Jersey, which once supported a major rail yard and port facility with docks for shipping cargo to New York City. ICP-MS and pyrolysis-GC-MS studies were used to show that our study site is contaminated with heavy metals and organic contaminants, including polycyclic aromatic hydrocarbons. We used fluorescence spectroscopy to measure soil enzymatic function at multiple locations within the brownfield and found the following types of sites: 1.) hotspots with high heavy metal concentrations and high extracellular …

Magnetocaloric Effect Near Room Temperature In Quintenary And Sextenary Heusler Alloys, Benjamin D. White, R. I. Barabash, O. M. Barabash, I. Jeon, M. B. Maple

All Faculty Scholarship for the College of the Sciences

An inverse magnetocaloric effect is studied in Ni₂Mn_1+xX_1-x-type Heusler alloys. Principally known for their shape-memory properties, these alloys also exhibit significant entropy and temperature changes (ΔS and ΔT_Ad, respectively) under adiabatic conditions when a modest magnetic field is applied. We investigated the impact on magnetocaloric properties of introducing substantial chemical disorder on the X-site (X = Si, Ga, In), of replacing Ni with nonmagnetic Ag, and of replacing a small amount of Mn with Gd. While a reduction in ΔS is observed in the first two cases, we observe a significant enhancement …

Growing Local: The Role Of Urban Gardening In Fostering Food Security, Sustainability, And Community, Franklin Wagner, Lindsey Payne

Purdue Journal of Service-Learning and International Engagement

The downtown center of Lafayette, Indiana is situated in a food desert where access to healthy, nutritious food can be limited. Urban gardens are an effective way to increase access to healthy alternatives while also providing a number of benefits to the surrounding area, including opportunities for community growth, education, and physical activity. In summer 2016, researchers from Purdue University collaborated with Lafayette’s GrowLocal Urban Gardens Network (GrowLocal) to perform a baseline analysis of the current community gardening initiatives, and explore the possibilities for expansion, development, and future community involvement through urban gardening.

Both qualitative and quantitative data collection methods …

Dam Removal In New Jersey: Ecological Uplift, Public Safety, And Building Ecosystem Resilience In Advance Of Climate Change, Beth Styler Barry

Sustainability Seminar Series

Dam removals are often the subject of controversy. We’ll explore dam removals from planning to (de)construction and see examples of ecosystem changes that follow. New Jersey has over 1700 dams, the average age of these dams is over 50 years. Many dams have a public use, they may provide a potable water supply or create economically important recreational lakes. However, many dams have outlived their intended use, have fallen into serious disrepair and negatively impact ecosystems.

A Look Under The Hood: Energy & Sustainability Initiatives At New Jersey Transit, John Geitner

Sustainability Seminar Series

New Jersey Transit (NJT) is the nation's largest statewide public transportation provider. To move its nearly one million daily customers, NJT operates Rail, Bus and Light Rail systems. Finding ways to use that energy efficiently and with an eye on sustainability is the focus of the Environment, Energy & Sustainability team at NJT. Join us for a detailed discussion on NJT's operations and how the agency works to incorporate various technologies and programs into those operations with the goal of using energy wisely. This presentation will discuss current capital projects and how they work to incorporate resiliency, reliability and sustainability …

Seeing With A Climate Lens, Jane Ganion

Year on Climate Change: Events

Join Jana Ganion from the Blue Lake Rancheria and Kit Batten, an independent climate change consultant previously at Pacific Gas & Electric to talk about a zero-emission future and your role in it. We will discuss insights and lessons learned from the clean energy and sustainability field through our work to shape a grid of the future. If you don’t yet know exactly what you want to do or you are have been working in these fields for decades, join us to talk about sustainability, electrical grids, climate, international diplomacy, the future, and you.

Living Landscapes: Combining Education And Ecology For A More Resilient New York Harbor, Murray Fisher, Brad Howe

Year on Climate Change: Events

This session will highlight a unique partnership between a landscape architecture firm, an environmental group, and a public high school that are working together in New York Harbor to increase the area’s resiliency as the climate changes, and to engage and train the next generation of environmental and Harbor stewards.

Study Group On Climate Change Recommendations Progress Report, Dano Weisbord

Year on Climate Change: Other Materials

Climate change is an urgent, complex problem. Human activities are pushing the climate beyond the range of conditions experienced over the last few million years and toward abrupt, unpredictable, highly damaging and potentially irreversible impacts. Effective responses will require ambitious, multifaceted plans of action.

Blue Economy And Climate Change: Bangladesh Perspective, Subrata Sarker, Firdaus Ara Hussain, Mohammad Assaduzzaman, Pierre Failler

Journal of Ocean and Coastal Economics

Blue Economy is related to economic growth through the sustainable utilization of ocean resources with technological inputs to improve livelihoods. Economically important coastal and marine resources are the main components of the Blue Economy for Bangladesh. These resources are categorized into living, non-living, renewable resources and trade and commerce. As Bangladesh is vulnerable to climate change, related extreme events are making the coastal and marine resources vulnerable which may hamper the smooth Blue Economy development in Bangladesh. Climate change extreme events include warming trend, cyclone, sea level rise, droughts, erosion, tidal surge, saline water intrusion, flood, change in precipitation trend …