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2019

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Articles 1111 - 1140 of 1657

Full-Text Articles in Earth Sciences

Miocene Glacial Dynamics Recorded By Variations In Magnetic Properties In The Andrill-2a Drill Core, Luigi Jovane, Fabio Florindo, Gary Acton, Christian Ohneiser, Leonardo Sagnotti, Eleonora Strada, Kenneth L. Verosub, Gary S. Wilson, Francesco Iacoviello, Richard H. Levy, Sandra Passchier Mar 2019

Miocene Glacial Dynamics Recorded By Variations In Magnetic Properties In The Andrill-2a Drill Core, Luigi Jovane, Fabio Florindo, Gary Acton, Christian Ohneiser, Leonardo Sagnotti, Eleonora Strada, Kenneth L. Verosub, Gary S. Wilson, Francesco Iacoviello, Richard H. Levy, Sandra Passchier

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

During the 2007 ANtarctic geological DRILLing (ANDRILL) campaign in the Ross Sea, Antarctica, the AND-2A core was recovered through a stratigraphic succession spanning 1,138.54 m of Neogene sedimentary rocks that include an expanded early to middle Miocene sequence. The study reported here focuses on the magnetic properties of the interval from 778.63 m below sea floor (mbsf) to 1,138.54 mbsf, which comprises a time interval spanning 1.5 Myr, from ~18.7 to ~20.2 Ma. We recognize three main pulses of increased input of magnetic materials to the drill site between 778.34–903.06, 950.55–995.78, and 1,040–1,103.96 mbsf. Trends in the magnetic mineral concentration …


Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust And Local Anthropogenic Sources, Michael Max Goodman Mar 2019

Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust And Local Anthropogenic Sources, Michael Max Goodman

Theses and Dissertations

Dust originating from dry lakes contributes harmful and toxic elements to downwind urban areas and mountain snowpack that is compounded by local contaminant inputs from anthropogenic sources. To evaluate dust contributions to an urban area from regional playas, we sampled playa dust sources, urban dust deposition, and snow dust deposition in central Utah, USA. Samples were analyzed for grain size, mineralogy, and chemistry. Bulk mineralogy between playa, urban, and snow dust samples was similar, with silicate, carbonate, and evaporite minerals. Grain size distribution between fine playa, urban, and snow dust particles was also similar. Elements found at high concentrations in …


Umphlett Qci March 2019, Natalie Umphlett Mar 2019

Umphlett Qci March 2019, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature Anomalies

Plains Snowpack

Agriculture

Energy

Transportation

Temperature

Precipitation


Multivariate Analysis Of Hydrochemical Data For Jewel Cave, Wind Cave, And Surrounding Areas, Andrew J. Long, James B. Paces, William G. Eldridge Mar 2019

Multivariate Analysis Of Hydrochemical Data For Jewel Cave, Wind Cave, And Surrounding Areas, Andrew J. Long, James B. Paces, William G. Eldridge

United States National Park Service: Publications

Abstract

Jewel Cave National Monument and Wind Cave National Park in South Dakota contain two of the six longest caves worldwide. These caves contain subterranean lakes that are important points of intersection between the water table of the Madison aquifer and the caves. During 2015 to 2017, several subterranean lakes were discovered in Jewel Cave, which previously was thought to be above the regional water table. The objectives of this study were to better understand the hydrology of the recently discovered subterranean lakes in Jewel Cave and to evaluate their relation or possible connection to similar lakes in Wind Cave. …


Mechanical Significance Of Morphological Variation In Diprotodont Incisors, Philip J.R. Morris, Philip G. Cox, Samuel N. Cobb Mar 2019

Mechanical Significance Of Morphological Variation In Diprotodont Incisors, Philip J.R. Morris, Philip G. Cox, Samuel N. Cobb

School of Geosciences Faculty and Staff Publications

All rodents possess a single pair of enlarged incisors that grow throughout life. This condition (diprotodonty) is characteristic of Rodentia, but is also found in other mammals such as lagomorphs, hyraxes, the aye-aye and common wombat. This study surveyed lower incisor morphology across extant diprotodonts to examine shape variation within and between rodents and other diprotodonts, and to determine if tooth shape varies in a manner predictable from mechanics. Six linear and area variables were recorded from microCT scans of the mandibles of 33 diprotodont mammals. The curvature of the rodent lower incisors, as measured by the proportion of a …


Ice-Cliff Failure Via Retrogressive Slumping, Byron R. Parizek, Knut Christianson, Richard B. Alley, Denis Voytenko, Irena Vaňková, Timothy H. Dixon, Ryan T. Walker, David M. Holland Mar 2019

Ice-Cliff Failure Via Retrogressive Slumping, Byron R. Parizek, Knut Christianson, Richard B. Alley, Denis Voytenko, Irena Vaňková, Timothy H. Dixon, Ryan T. Walker, David M. Holland

School of Geosciences Faculty and Staff Publications

Retrogressive slumping could accelerate sea-level rise if ice-sheet retreat generates ice cliffs much taller than observed today. The tallest ice cliffs, which extend roughly 100 m above sea level, calve only after ice-flow processes thin the ice to near flotation. Above some ice-cliff height limit, the stress state in ice will satisfy the material-failure criterion, resulting in faster brittle failure. New terrestrial radar data from Helheim Glacier, Greenland, suggest that taller subaerial cliffs are prone to failure by slumping, unloading submarine ice to allow buoyancy-driven full-thickness calving. Full-Stokes diagnostic modeling shows that the threshold cliff height for slumping is likely …


Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle Mar 2019

Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle

Civil and Environmental Engineering Faculty Publications and Presentations

Ecosystem water-use efficiency (WUE) is defined as the ratio of carbon gain (i.e., gross primary productivity; GPP) to water consumption (i.e., evapotranspiration; ET). WUE is markedly influential on carbon and water cycles, both of which are fundamental for ecosystem state, climate and the environment. Drought can affect WUE, subsequently disturbing the composition and functionality of terrestrial ecosystems. In this study, the impacts of drought on WUE and its components (i.e., GPP and ET) are assessed across the Contiguous US (CONUS) at fine spatial and temporal resolutions. Soil moisture simulations from land surface modeling are utilized to detect and characterize agricultural …


Wayne E. Sabbe Arkansas Soil Fertility Studies 2018, Nathan A. Slaton Mar 2019

Wayne E. Sabbe Arkansas Soil Fertility Studies 2018, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.


Nebraska Statewide Groundwater-Level Monitoring Report 2018, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, Sue Olafsen Lackey, Robert Matthew Joeckel Mar 2019

Nebraska Statewide Groundwater-Level Monitoring Report 2018, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the State. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

The personnel of the Conservation and Survey Division (CSD) are pleased …


Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith Mar 2019

Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. We characterize the seasonal origins of waters in soils and trees by comparing their midsummer isotopic signatures (δ2H) to seasonal isotopic cycles in precipitation, using a new seasonal origin index. Across 182 Swiss forest sites, xylem water isotopic signatures show that summer rain was not the predominant water source …


A New Direction For Salinity Management In Western Australia: A Consultative Review, Ghd Mar 2019

A New Direction For Salinity Management In Western Australia: A Consultative Review, Ghd

Natural resources commissioned reports

In May 2018, the Office of the Auditor General (OAG) published an audit into the management of salinity and recommended that the Department of Primary Industries and Regional Development (DPIRD), in consultation with the Department of Biodiversity, Conservation and Attractions (DBCA) and the Department of Water and Environmental Regulation (DWER), set a strategic direction for salinity management for WA and improve monitoring, cooperation, coordination, promotion of soil conservation, and compliance of salinity impacts and its management.

The OAG’s audit focused on two questions:

  1. Do agencies know the extent and impact of dryland salinity in the South West agricultural regions?
  2. Are …


Uwrl Faculty Member Randy Martin Gives First Usu Research Landscapes Lecture, Utah Water Research Laboratory Feb 2019

Uwrl Faculty Member Randy Martin Gives First Usu Research Landscapes Lecture, Utah Water Research Laboratory

News

On February 26th, Dr. Randy Martin, a Utah Water Research Laboratory faculty member and Associate Research Professor in the USU Department of Civil and Environmental Engineering, gave Utah State University’s first Research Landscapes lecture in Salt Lake City.


High-Resolution Record Reveals Climate-Driven Environmental And Sedimentary Changes In An Active Rift, Lisa C. Mcneill, Donna J. Shillington, Gareth D. O. Carter, Jeremy D. Everest, Robert L. Gawthorpe, Clint Miller, Marcie P. Phillips, Richard E. Ll. Collier, Aleksandra Cvetkoska, Gino De Gelder, Paula Diz, Mai-Linh Doan, Mary Ford, Maria Geraga, Jack Gillespie, Romain Hemelsdael, Emilio Herrero-Bervera, Mohammad Ismaiel, Liliane Janikian, Katerina Kouli, Erwan Le Ber, Shunli Li, Marco Maffione, Carol Mahoney, Malka L. Machlus, Georgios Michas, Casey W. Nixon, Sabire Asli Oflaz, Abah P. Omale, Kostas Panagiotopoulos, Sofia Pechlivanidou, Simone Sauer, Joana Seguin, Spyros Sergiou, Natalia V. Zakharova, Sophie Green Feb 2019

High-Resolution Record Reveals Climate-Driven Environmental And Sedimentary Changes In An Active Rift, Lisa C. Mcneill, Donna J. Shillington, Gareth D. O. Carter, Jeremy D. Everest, Robert L. Gawthorpe, Clint Miller, Marcie P. Phillips, Richard E. Ll. Collier, Aleksandra Cvetkoska, Gino De Gelder, Paula Diz, Mai-Linh Doan, Mary Ford, Maria Geraga, Jack Gillespie, Romain Hemelsdael, Emilio Herrero-Bervera, Mohammad Ismaiel, Liliane Janikian, Katerina Kouli, Erwan Le Ber, Shunli Li, Marco Maffione, Carol Mahoney, Malka L. Machlus, Georgios Michas, Casey W. Nixon, Sabire Asli Oflaz, Abah P. Omale, Kostas Panagiotopoulos, Sofia Pechlivanidou, Simone Sauer, Joana Seguin, Spyros Sergiou, Natalia V. Zakharova, Sophie Green

Publications and Research

Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvinronmental changes when a young rift connects to the global concerns. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift shows 10s-100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and …


A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak Feb 2019

A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak

Computer Information Technology Faculty Publications

The realization of Internet of Underground Things (IOUT) relies on the establishment of reliable communication links, where the antenna becomes a major design component due to the significant impacts of soil. In this paper, a theoretical model is developed to capture the impacts of change of soil moisture on the return loss, resonant frequency, and bandwidth of a buried dipole antenna. Experiments are conducted in silty clay loam, sandy, and silt loam soil, to characterize the effects of soil, in an indoor testbed and field testbeds. It is shown that at subsurface burial depths (0.1-0.4m), change in soil moisture impacts …


Effect Of Stoniness On The Hydraulic Properties Of A Soil From An Evaporation Experiment Using The Wind And Inverse Estimation Methods, Nerea Arias, Iñigo Virto, Alberto Enrique, Paloma Bescansa, Riley Walton, Ole O. Wendroth Feb 2019

Effect Of Stoniness On The Hydraulic Properties Of A Soil From An Evaporation Experiment Using The Wind And Inverse Estimation Methods, Nerea Arias, Iñigo Virto, Alberto Enrique, Paloma Bescansa, Riley Walton, Ole O. Wendroth

Plant and Soil Sciences Faculty Publications

Stony soils are distributed all over the world. The study of their characteristics has gained importance lately due to their increasing use as agricultural soils. The effect that rock fragments exert on the soil hydraulic properties is difficult to measure in situ, and is usually derived from the fine earth properties. However, the corrections used so far do not seem accurate for all types of stony soils. Our objective was to assess the adequacy of estimating the hydraulic properties of a stony soil from the fine earth ones by correcting the latter by the volume occupied by rock fragments. To …


Limits To The World’S Green Water Resources For Food, Feed, Fiber, Timber, And Bioenergy, Joep F. Schyns, Arjen Y. Hoekstra, Martijn J. Booij, Rick J. Hogeboom, Mesfin Mekonnen Feb 2019

Limits To The World’S Green Water Resources For Food, Feed, Fiber, Timber, And Bioenergy, Joep F. Schyns, Arjen Y. Hoekstra, Martijn J. Booij, Rick J. Hogeboom, Mesfin Mekonnen

Daugherty Water for Food Global Institute: Faculty Publications

Green water––rainfall over land that eventually flows back to the atmosphere as evapotranspiration––is the main source of water to produce food, feed, fiber, timber, and bioenergy. To understand how freshwater scarcity constrains production of these goods, we need to consider limits to the green water footprint (WFg), the green water flow allocated to human society. However, research traditionally focuses on scarcity of blue water––groundwater and surface water. Here we expand the debate on water scarcity by considering green water scarcity (WSg). At 5 × 5 arc-minute spatial resolution, we quantify WFg and the maximum sustainable level to this footprint (WFg,m), …


Research On Key Technology Of The 15 000 N·M High-Power Directional Drilling Rig, Fang Peng Feb 2019

Research On Key Technology Of The 15 000 N·M High-Power Directional Drilling Rig, Fang Peng

Coal Geology & Exploration

According to the actual demand for ultra-long distance directional drilling in coal seam and large diameter directional drilling in seam roof, and the function of compound directional drilling technology for drilling rig, the technical idea of modular development for the functional development and design of high-power directional drilling rig are put forward. Combined with the contradiction among high-power matching, large capacity output and compact layout design of drilling rig, the key technologies of 15 000 N·m high-power directional drilling rig are researched in this paper, including overall layout design, large capacity rotary head design and layer board analysis, large opening …


Hole-Bottom Hydraulic Pressurization Technology For Directional Drilling In Hard Rock In Underground Coal Mines, Xu Baolong, Yao Ningping, Wang Li, Cao Jing, Dou Xuqian Feb 2019

Hole-Bottom Hydraulic Pressurization Technology For Directional Drilling In Hard Rock In Underground Coal Mines, Xu Baolong, Yao Ningping, Wang Li, Cao Jing, Dou Xuqian

Coal Geology & Exploration

In order to solve the problem of large feeding pressure, low drilling efficiency and limited hole depth caused by the backing effect of drill string during directional drilling of deep hole in underground coal mines, a technical idea of using hydraulic tool to increase WOB was proposed. The structural design of the hydraulic pressurizer at the bottom of the hole was carried out by drawing on the structure of the hydraulic pressurizer in the field of oil drilling and combining the nearly horizontal drilling conditions in underground coal mines. The hydraulic parameters were designed by the theoretical calculation and the …


Progress And Prospects Of Coal Geological Work In Tibet, Qiao Junwei, Ning Shuzheng, Song Shiyu, Yang Cheng Feb 2019

Progress And Prospects Of Coal Geological Work In Tibet, Qiao Junwei, Ning Shuzheng, Song Shiyu, Yang Cheng

Coal Geology & Exploration

Through the summary of the coal geological work and achievements in Tibet for nearly 70 years, the current status and main results of coal geological exploration in the main coal mines in the region were reviewed. The formation age, distribution range, coal content and coal quality characteristics of coal-bearing strata in major coal mines in the region were found out. The division of coal-bearing tectonic units and coal-accumulating basins in Tibet was summarized, and the sedimentary systems and sedimentary environments of coal-bearing strata in the main coal-forming periods were preliminarily summarized. It is generally believed that the overall degree of …


Analysis Of Diffusion Properties Of Methane In Low Rank Coal, Meng Zhaoping, Zhang Guiyuan, Li Guoqing, Liu Jinrong Feb 2019

Analysis Of Diffusion Properties Of Methane In Low Rank Coal, Meng Zhaoping, Zhang Guiyuan, Li Guoqing, Liu Jinrong

Coal Geology & Exploration

Diffusion properties of methane in coal is an important reservoir parameter affecting CBM production. Using the lignite samples from the Xiaolongtan Formation of the Miocene Neogene in southeastern Yunnan Province, the isothermal adsorption experiments of methane in low rank coal were carried out. Based on the relationship between adsorption amount and time obtained from isothermal adsorption experiment, the diffusion coefficient of methane in coal was calculated by using an unipore model of unsteady gas diffusion. The diffusion law of methane in coal and its control mechanism were revealed. The results show that gas diffusion law in coal obeys Langmuir equation; …


Study On Complex Resistivity Of Artificial Sandstone Containing Conductive Mineral Under High Pressure, Tian Gang, Tang Xingong, Xiang Kui, Chi Meiyao Feb 2019

Study On Complex Resistivity Of Artificial Sandstone Containing Conductive Mineral Under High Pressure, Tian Gang, Tang Xingong, Xiang Kui, Chi Meiyao

Coal Geology & Exploration

Due to the complex pore structure and non-single skeleton composition, natural rock samples are more difficult to study than artificial rock samples. The standard rock samples with different mineral content and volume content were artificially synthesized by using brass powder, pyrite sand, graphite powder, epoxy resin, etc. Complex resistivity measurements were taken to the samples by using AutoLab-1000 equipment under different formation pressure conditions. The complex resistivity and the parameters of zero frequency resistivity, polarizability, and time constant of the artificial sandstone standard were derived based on Debye decomposition model. Made a discussion on relationship between parameters of the model, …


Theoretical Research On The Ploughing Rock Breaking Properties Of New Conical Pdc Cutter, Ju Pei, Wang Chuanliu Feb 2019

Theoretical Research On The Ploughing Rock Breaking Properties Of New Conical Pdc Cutter, Ju Pei, Wang Chuanliu

Coal Geology & Exploration

The researches on the conical PDC cutter are now focused on numerical simulation, field and laboratory tests, the theoretical analysis on its mechanical properties has not been reported. Therefore, the tensile shear rock breaking mechanism and cutting load distribution characteristics of the conical PDC cutter are described by numerical simulation, the theoretical formula of the cutting load is derived according to the energy balance principle. Results show that comparing with the conventional cylindrical PDC cutter, the rock breaking process of conical PDC cutter is more stable, the cutting load is influenced by the rock properties, the parameters of cutter structure, …


Model Of Gas-Bearing Coal Permeability Prediction Based On Apso-Wls-Svm, Mao Zhiyong, Huang Chunjuan, Lu Shichang, Han Rongyue Feb 2019

Model Of Gas-Bearing Coal Permeability Prediction Based On Apso-Wls-Svm, Mao Zhiyong, Huang Chunjuan, Lu Shichang, Han Rongyue

Coal Geology & Exploration

In order to predict gas-bearing coal permeability accurately and prevent gas accidents effectively, a weighted least square support vector machine(WLS-SVM) algorithm based on Adaptive Particle Swarm Optimization(APSO) is proposed. Based on the related theory and literature research on gas-bearing coal permeability, the effective stress, gas pressure, temperature and compressive strength were selected as the main characteristic indexes. The APSO algorithm was used to optimize the combination parameters(C, σ) of the WLS-SVM model and APSO-WLS-SVM gas-bearing coal permeability prediction model was established. According to the field data, 40 sets of data were used as training samples and the remaining …


Study On Development Height Of Permeable Fractured Zone Based On Overburden Failure Transfer, Zhao Gaobo, Guo Wenbing, Lou Gaozhong, Ma Zhibao Feb 2019

Study On Development Height Of Permeable Fractured Zone Based On Overburden Failure Transfer, Zhao Gaobo, Guo Wenbing, Lou Gaozhong, Ma Zhibao

Coal Geology & Exploration

It is extremely significant for coal mining under water bodies and water conservation mining to research overburden failure and the height of permeable fractured zone. The processes of overburden failure transfer were analyzed, which could be divided into transmission development stage and transmission termination stage. Through theoretical analysis, mechanical model of strata suspended integrity and overhanging stability were established. The limited suspension distance and overhang distance of each stratum were proposed to judge the damage of each layer. A new theoretical method to predict the development height of permeable fractured zone was put forward. The project example was compared with …


Data Modeling And Analysis Of Coal Resources Based On 3dmine Software, Liu Xiaoning, Luo Jinhui, Ma Xiaoli, Dong Zhibo Feb 2019

Data Modeling And Analysis Of Coal Resources Based On 3dmine Software, Liu Xiaoning, Luo Jinhui, Ma Xiaoli, Dong Zhibo

Coal Geology & Exploration

Taking No.3 coal in Gucheng coal mine, Shandong Province as the target, 3D coal seam entity models were built in 3DMine software, coaly quality indices' distributions were analyzed and coal reserve was calculated and compared to the reserve estimation in method of geological block. Firstly, a boreholes database is established using the geological data and borehole data of the target, and a 3D surface model of the coal seam with faults embedded was constructed. Then, the surface model was interpolated into an entity blocks model through the algorithm of inverse distance weighted(IDW) interpolation. Finally, the recoverable coal reserve of the …


Research On Collapsibility Of A Loess Site In Pakistan, Liu Chunlong, Zhang Zhiqiang, Liu Fengyin, Liu Naifei, Sun Hongchao, Lyu Wenjun Feb 2019

Research On Collapsibility Of A Loess Site In Pakistan, Liu Chunlong, Zhang Zhiqiang, Liu Fengyin, Liu Naifei, Sun Hongchao, Lyu Wenjun

Coal Geology & Exploration

The loess of an area in Pakistan is the Quaternary Holocene alluvium. The study and existing geological data in this area are relatively few, and special research is needed. In order to determine the distribution and collapsibility of the lo-ess, based on the construction distribution of the loess site, undisturbed soil sample was selected at the typical location. The unconfined compression strength tests and compressive tests were carried out. The structural characteristics of loess were quantitatively described by structural index. The self-weight collapsible coefficient and collapsible coefficient of loess were determined, the self-weight settlement and the total settlement were calculated …


Table Of Contents, The Editors Feb 2019

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Technology And Method Of Cbm Concurrent Exploration During Coal Resources Exploration, Lin Yabing, Qin Yong, Duan Zhonghui, Ma Dongmin Feb 2019

Technology And Method Of Cbm Concurrent Exploration During Coal Resources Exploration, Lin Yabing, Qin Yong, Duan Zhonghui, Ma Dongmin

Coal Geology & Exploration

The coal seam serves as a geological carrier for CBM, and exploration of CBM and coal resources is a man-datory requirement for the management of national mineral resources. Based on the practice of project exploration in recent years, it analyzed the evaluation criteria of CBM resources in the process of coal resources exploration. On this basis, the exploration ideas, exploration methods, tasks, report preparations have proposed a method system for CBM in the ex-ploration of coal resources. According to the particularity of CBM exploration work methods, CBM seismic, well logging, drilling, well log, gas drainage, and engineering quality acceptance methods …


Timing And Rates Of Events In The Generic Volcanic Earthquake Swarm Model, Tianyu Rong Feb 2019

Timing And Rates Of Events In The Generic Volcanic Earthquake Swarm Model, Tianyu Rong

USF Tampa Graduate Theses and Dissertations

In this thesis I combine data from 29 volcanic earthquake swarms that follow the pattern predicted by the Generic Volcanic Earthquake Swarm Model (GVESM; Benoit and McNutt, 1996) to investigate whether the relative timing of various parameters of pre-eruptive volcanic earthquake swarms could be used to forecast the time of an impending eruption. Based on the analysis of seismic unrest preceding many eruptions, the GVESM suggests that it is common to see an increase first in high-frequency earthquakes, then low-frequency earthquakes, then the onset of volcanic tremor. While this pattern is useful to volcano-seismologists, the relative timing and durations of …


Experimental Of Water Unlocking Stimulation Mechanism On Surfactant Fracturing Fluid, Song Jinxing, Yu Shiyao, Su Xianbo, Wang Qian Feb 2019

Experimental Of Water Unlocking Stimulation Mechanism On Surfactant Fracturing Fluid, Song Jinxing, Yu Shiyao, Su Xianbo, Wang Qian

Coal Geology & Exploration

This paper presents an experimental study of water unlocking stimulation mechanism on surfactant fracturing fluid based on the measurements of surface tension, contact angle, gas-phase permeabilities and desorption of nitrogen on synthetic coal samples. The coking coal in Liulin zone of Hedong coal field was used as testing object in this study. Active water and surfactant fracturing fluids were used as testing liquids in this study. Results show that the surfactant fracturing fluid(1.5%KCl+0.05%AN) reduces the surface tension of active water fracturing fluid(1.5%KCl) and increases the wettabil-ity of active water fracturing fluid to coal reservoir; the surfactant fracturing fluid reduces the …