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Fractal Theory-Based Permeability Model Of Fracture Networks In Coals, Xia Binwei, Liao Chuanbin, Luo Yafei, Ji Kainan

Coal Geology & Exploration

Fractures in coal reservoirs, which act as the major seepage pathways for coalbed methane (CBM), determine the permeability and CBM productivity of coal reservoirs. Research on the relationships between fracture structures and reservoir permeability is of great theoretical and practical significance for the accurate prediction of CBM productivity. Based on the classical cubic law-based permeability model, as well as the fractal theory, fracture network structures, and effective stress, this study built a permeability model containing complex bending fractures, which was then combined with the S & D (Shi-Durucan) model to build the permeability model of fractured coals under the action …

A Method For Classification Of Surrounding Rock Based On The Excavatability Performance And Adaptability Of Tunnel Boring Machines And Its Applications, Liu Jiawei, Zhang Sheng, Chen Zhao, Yang Zhanbiao, Ji Panjun, Wei Yonghui

Coal Geology & Exploration

The varying geological conditions of the surrounding rocks of coal mine roadways influence the wide application of full-face rock tunnel boring machines (TBMs). Therefore, accurately assessing the excavatability of rock masses in coal mines and the rock adaptability of TBMs is crucial for the efficient operation of TBMs. Based on the evaluation results of the parameters and excavatability of rock masses, this study built a classification model for rock mass excavatability using the technique for order preference by similarity to ideal solution (TOPSIS). Furthermore, combining the correlation analysis between the [BQ] values of different geological conditions and the utilization ratio …

Drillability And Mechanical Parameters Of Laser Hot Cracking Sandstones, Yang Lei, Yang Bengao, Liu Junjun, Zhou Xuemin, Xie Jing, Wang Chen, Guo Chenchen, Gao Mingzhong

Coal Geology & Exploration

Over recent years, shallow coal resources that can be easily mined have been gradually exhausted. As a result, conventional drilling techniques tend to face challenges such as low rock-breaking efficiency, high drilling costs, and environmental pollution in the exploration and exploitation of deep coal resources. Therefore, there is an urgent need to introduce a new auxiliary rock-breaking technique for drilling. Focusing on the new laser-assisted rock-breaking technology, this study systematically conducted mechanical and drillability tests on sandstones after laser irradiation for different durations, aiming to explore the temporal and spatial evolution of the temperature field of hard sandstones, the propagation …

Physical And Mechanical Properties Of Thermal Insulation Materials For In-Situ Temperature-Preserved Coring Of Deep Rocks, Xue Shouning, He Zhiqiang, Li Cong, Yu Bo, Lu Xuelian, Liu Wenyue, Yang Jianping, Wei Zijie

Coal Geology & Exploration

High temperature affects deep coal mining and other engineering activities. However, conventional coring methods for terrestrial hard rocks lack temperature-preserved measures, ignoring the effects of temperature on the physical and mechanical properties of rocks. Consequently, the parameters obtained are subjected to distortion, affecting the safe and efficient mining of resources such as deep coals. To make breakthroughs in the development of in-situ temperature-preserved coring technologies for deep rocks, this study proposed using the hollow glass microsphere/epoxy resin (HGM/EP) as thermal insulation materials and the physical and mechanical properties. The results are as follows: (1) With an increase in the HGM …

Evaluation Of Site-Specific, Zone Management In Northeast Arkansas Cotton, Nelson Ray Benson

Student Theses and Dissertations

Temporal and spatial variations in crop performance are common in agricultural production fields in northeastern Arkansas. With the alluvial soils of the Mississippi Delta region, within-field soil texture can range from coarse sand to heavy clay. Such variability influences chemical and physical soil properties that affect yield potential of the region’s commercial cropping systems. With advances in precision management, delineating large commercial fields into zones of homogenous production potential could increase profitability and improve efficiency. Standardized criteria for defining homogeneity within potential delineation zones have not been developed or field-tested in the region, which includes Mississippi County, Arkansas, the largest …

Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong

Coal Geology & Exploration

The in-situ gas pressure and content of coal seams are critical for the safe production of deep coal mines and the accurate evaluation of coalbed methane resources. To address the technical challenges of accurately determining in-situ gas content in deep coal seams, this study proposed brand-new principles of in-situ pressure coring and the tests of in-situ gas content and pressure. It also derived a calculation method for in-situ gas content in coal seams and a method for determining the in-situ gas pressure while considering the effects of moisture content and multiple gas components. Given the in-situ stress environment deep in …

A Preliminary Study Of Pressure-Preserved Coring Calculation Principle And Method For In-Situ Pressure In Deep Coal Seams, Cui Pengfei, Gao Mingzhong, Shang Delei, Li Jianhua, Chu Peng, Song Jie, Li Yongcheng, Hao Haichun

Coal Geology & Exploration

The accurate acquisition of in-situ gas pressure in coal seams is a key link in the chain of the prevention and control of gas disasters. Presently, it is still necessary to explore accurate, low-cost, and time-saving methods for determining gas pressure. Based on the in-situ pressure-preserved coring for deep coal seams, this study proposed a calculation method for in-situ gas pressure in deep coal seams and developed the calculation process. Using the constructed numerical model of the gas pressure evolution in the pressure-preserved space, this study verified the reliability of the proposed method by comparison with the theoretical and numerical …

Influence Of Gas Components On The Determination Of Gas Pressure In Coal Seams Under In-Situ Pressure-Preserved Coring, Chu Peng, Shang Delei, Li Jianhua, Ma Shaoming, Zhu Guodong, Cui Pengfei

Coal Geology & Exploration

Determining the pressure and content of coal seam gas based on pressure-preserved coring is an effective method for quickly and accurately calculating gas parameters. Coal seam gas is a multi-component gas mixture dominated by methane. Given that coals show different adsorption capacities for different gases and that the components in the mixed gas exhibit different partial pressures, the proportions of gas components can influence the calculation results of the content and pressure of coal seam gas. To accurately determine the in-situ gas pressure in coal seams based on the pressure-preserved coring, this study investigated the influence of gas components on …

Exploring The Wetting Mechanism Of Surfactants For Coals Based On Molecular Simulations, Tong Yanjun, Yang Zundong, Song Jie, Li Yongcheng, Liu Yiting

Coal Geology & Exploration

With a gradual increase in the depth and mechanization degree of coal mining, secondary explosions of gas and coal dust have become increasingly severe. Chemical dust suppressants such as surfactants can reduce these explosions by effectively inhibiting the generation and diffusion of coal dust. To explore the inhibition mechanism of nonionic surfactants for hydrophobic coal dust, this study analyzed the basic physicochemical properties of typical hydrophobic coal dust at a depth of 1050 m using FT-IR, XRF, and XRD. This study built a molecular structure model of coal dust by combining test techniques such as EA, XPS, and ¹³C …

The Patchwork Governance Of Ecologically Available Water: A Case Study In The Upper Missouri Headwaters, Montana, United States, Amanda E. Cravens, Julia B. Goolsby, Theresa Jedd, Deborah J. Bathke, Shelley Crausbay, Ashley E. Cooper, Jason Dunham, Tonya Haigh, Kimberly R. Hall, Michael J. Hayes, Jamie Mcevoy, Rebecca L. Nelson, Markéta Poděbradská, Aaron Ramirez, Elliot Wickham, Dionne Zoanni

National Drought Mitigation Center: Faculty Publications

Institutional authority and responsibility for allocating water to ecosystems (“ecologically available water” [EAW]) is spread across local, state, and federal agencies, which operate under a range of statutes, mandates, and planning processes. We use a case study of the Upper Missouri Headwaters Basin in southwestern Montana, United States, to illustrate this fragmented institutional landscape. Our goals are to (a) describe the patchwork of agencies and institutional actors whose intersecting authorities and actions influence the EAW in the study basin; (b) describe the range of governance mechanisms these agencies use, including laws, policies, administrative programs, and planning processes; and (c) assess …

Applications Of Observational Seismology: Insights Into Volcanic And Near Surface Processes, Justin T. Wilgus

Earth and Planetary Sciences ETDs

The field of observational seismology has made tremendous progress in the past two decades. This progress has been multi-faceted in form, but significant contributions emanated from 1) increases in both the quality and the quantity of seismic data 2) advances in computational power 3) advances in algorithmic capability, including machine learning. In this dissertation I report on three distinctly different seismic applications made possible by the aforementioned progress and discuss the insights these applications have provided in understanding volcanic and near surface processes of the Earth.

In the first chapter titled, “Shear Velocity Evidence of Upper Crustal Magma Storage Beneath …

Insar Time Series Analysis To Evaluate Subsidence Risk Of Monumental Chandigarh City (India) And Surroundings, Jungrack Kim, Shih-Yuan Lin, Tejpal Singh, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Groundwater depletion is one of the serious geo-environmental issues causing ground subsidence, which damage buildings, infrastructures and causes loss of life. The quantitative and qualitative evaluation of groundwater variability requires multiple approaches to measure hydraulic head level and geodetic deformation. In this study, we have made efforts to integrate multiple hierarchical space-borne data, including Gravity Recovery and Climate Experiment (GRACE), Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR), geological and hydrological data, to quantify subsidence in Chandigarh city and its surroundings. First, we conducted New-Small BAseline Subsets (NSBAS) and pointwise persistent scatterer (PS) InSAR techniques in parallel, using three-years Sentinel-1 data showing …

Season, Not Long-Term Warming, Affects The Relationship Between Ecosystem Function And Microbial Diversity, Melissa S. Shinfuku, Luiz A. Domeignoz-Horta, Mallory J. Choudoir, Serita D. Frey, Kristen M. Deangelis

Faculty Publications

Across biomes, soil biodiversity promotes ecosystem functions. However, whether this relationship will be maintained under climate change is uncertain. Here, using two long-term warming experiments, we investigated how warming affects the relationship between ecosystem functions and microbial diversity across seasons, soil horizons, and warming duration. The soils in these warming experiments were heated +5 °C above ambient for 13 or 28 years. We measured seven different ecosystem functions representative of soil carbon cycling, soil nitrogen cycling, or nutrient pools. We also surveyed bacterial and fungal community diversity. We found that the relationship between ecosystem function and bacterial diversity and the …

Detection And Identification Of Pre-Seismic Thermal Anomalies In Cloudy Conditions Associated With The 2022 Luding (China) Mw 6.6 Earthquake, Feng Jing, Meng Jiang, Lu Zhang, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Over the past three decades, thermal anomalies from satellite infrared data have been widely discussed and associated with earthquakes. Besides infrared satellite data, the recent use of passive microwave satellite data has emerged as an important dataset to detect the potential thermal anomalies prior to earthquakes in all weather conditions due to its capability to monitor the earth in cloudy and foggy conditions and has been applied to the numerous strong earthquake events around the world. On 5 September 2022, an Mw 6.6 earthquake occurred in Luding county, nearby Mt. Gongga, China, with heavy cloud coverage over the epicenter and …

Grounding Line And Calving Front Retreat In Glomar Challenger Basin And Pennell Trough Of Ross Sea, Antarctica Reconstructed From Diatom Abundances And Assemblages, Jaren Bradford

LSU Master's Theses

Previous studies showed that West Antarctic Ice Sheet (WAIS) retreat from the Whales Deep Basin continental shelf edge in eastern Ross Sea was underway by 14.7 ± 0.4 cal kyr BP. Following an ice-shelf breakup at 12.3 ± 0.6 cal kyr BP, a calving cliff margin remained within 60 km of the shelf edge until 11.5 ± 0.3 cal kyr BP. McGlannan et al. (2017) inferred that an ice shelf reformed immediately during a subsequent rapid retreat. That interpretation of grounding-line retreat with an intact ice shelf is being reevaluated by Sivils (in prep.). Here, we conducted a similar synthesis …

Response Of Four Local Cassava Accessions To Bio-Mulch Application Time, Bayu Suwitono, Muhamad Achmad Chozin, Dwi Guntoro, Suwarto

Jurnal Kultivasi

Cassava (Manihot esculenta Crantz) is widely planted on marginal land with low soil fertility. During the initial growth phase, cassava often loses competition against weeds. Legume cover crops are widely used to increase soil fertility, prevent erosion, and suppress weeds. This study aimed to determine the effect of Arachis pintoi bio-mulch application time on the growth and yield of cassava. This study was conducted using a factorial randomized block design. The first factor was four cassava accessions: Ketan Malang, Genjah Bayam, IR Jonggol, and Mangu. The second factor was six levels of bio-mulch planting time: manual weeding (without bio-mulch applications), …

Effectiveness Of Modified Nitrogen Fertilizer On Soil Chemical Properties And Rice Plant Growth In The Textile Industrial Area, Rija Sudirja, Santi Rosniawaty, Sri Muji Rahayu, Budy Frasetya Taufik Qurrohman

Jurnal Kultivasi

The imbalance of nutrients and heavy metal contamination is a challenge in increasing plant growth surround the textile industry area. This study aimed to determine the effectiveness of the dosage of Biologically Agent N Organo Mineral Fertilizer (Biomix-N) as a fertilizer and an ameliorant in paddy soil contaminated with textile liquid waste. This study used a randomized block design of eight treatments with four replications. Parameters observed were soil chemical properties after application of Biomix-N (Na-ex, total N, EC, Cd, and pH), rice plant growth (plant height and tiller number), Cd concentration in the plant, and relative agronomic effectiveness (RAE). …

Scaling Up Of Site Carbon Dynamics To Predict The Carbon Dynamics In Kazakhstan, Central Asia, B. K. Wylie, Tagir Gilmanov, S. L. Stensaas, N. Z. Saliendra, D. A. Johnson, K. Akshalov, S. B. Frank, L. Zhang, R. F. Doyle, E. A. Laca, Montague W. Demment

IGC Proceedings (1977-2023)

Climate and management determine whether rangelands are net carbon sources or carbon sinks. Regional carbon dynamics of the Kazakh Steppe has not previously been documented. The objective of this study is to quantify the regional carbon flux dynamics of these extensive steppes.

A New System For Plant Experiments On Biodiversity Or Multi-Species Competition, John Connolly, L. Kirwan

IGC Proceedings (1977-2023)

Considerable discussion in recent years has focused on the design of competition and biodiversity experiments (Connolly et al., 2001a; Allison, 1999). Few agronomic experiments with >2 plant species have been conducted in greenhouse conditions (Gibson et al, 1999) or in the field (Connolly et al., 2001b). In many experiments the effects of density and initial species size have been confounded. The effects of species richness and evenness also are confounded frequently. The proposed system provides a framework of design and analysis, in which to address questions of function at community level and of structure and competition at …

Native Grasses Seeded Into A Cool-Season Pasture Encouraged By Low Resource Availability, J. E. Doll, R. L. Cates, R. D. Jackson

IGC Proceedings (1977-2023)

Native prairie of the Upper Midwest, which was dominated by warm-season (C₄) grasses, now exists as relatively small relict and restored patches (Curtis 1959). Re-introduction of natives into grazed agroecosystems would promote genetic, species, and landscape diversity. Extensive re-introduction of C₄ grasses will require a shift away from the paradigm of maximizing production because C₄ grasses have higher C:N ratios than C₃ grasses rendering them inferior forage species. Nonetheless, there is great interest amongst the grazing community of the Upper Midwest in establishing native grasses as a means of improving wildlife habitat and increasing belowground …

The Ag-Biota Project: A Preliminary Assessment Of Potential Indicators Of Biodiversity In Agricultural Grasslands, Gordon Purvis, A. Anderson, A. J. Helden, L. Kirwan

IGC Proceedings (1977-2023)

In compliance with European commitments to the Convention on Biological Diversity, the conservation and enhancement of biodiversity within agricultural land is a primary objective of current agri-environmental measures. However, there is a widespread lack of information concerning the effectiveness of agri-environmental schemes in Europe, (Kleijn & Sutherland, 2003). In large part, this is due to uncertainties about selection of appropriate biological indicators of biodiversity (Buchs, 2003; Duelli & Obrist, 2003).

Effects Of Plant Species Diversity In Multifunctional Grasslands On Avian Communities, K. K. Bakker, K. F. Higgins

IGC Proceedings (1977-2023)

Grasslands, planted or native sod, can provide multiple simultaneous functions (e.g., hay-forage production, biomass fuel products, bird nesting cover, soil and water conservation). Bird use of and abundance in grasslands is dependent on vegetation structure, size, and surrounding landscape (Bakker et al., 2002) but little is known about avian relationships to plant species diversity. We evaluated the relationship between plant species diversity and avian community structure in 5 grassland types. The results have application to grazing, haying, burning, and conservation practices applied to native and sown grassland stands and to conservation strategies for declining grassland bird populations.

Diversity And Adaptation Of Perennial Plants From North Africa: Legumes And Grasses, Aissa Abdelguerfi, M. Laouar, K. Abbas, M. M'Hammedi Bouzina

IGC Proceedings (1977-2023)

A variety of climates, soil types and reliefs characterise North Africa (Algeria, Morocco, and Tunisia). These natural conditions have produced a large diversity of environments, landscapes, plant formations and flora. Several factors have contributed to the spread of a wide floristic variety: the influence of the Mediterranean in the north and in the north-east, the Atlantic in the west, and the Sahara in the south, as well as the presence of mountain ranges, particularly the Rif, the Tell Atlas, the Sahara Atlas, the Middle Atlas, the High Atlas, and the Anti-Atlas. This diversity of landscapes, environments and ecosystems has generated …

Comparison Of Compositional Changes In Multi-Species Grass/Legume Mixture Experiments Across Three Nordic Countries (Iceland, Sweden And Finland) Over Two Years, Caroline Brophy, Anne-Maj Gustavsson, A. Helgadottir, Oiva Nissinen, J. Connolly

IGC Proceedings (1977-2023)

A multi-site experiment was established at 39 sites across Europe, Australia and Canada within COST Action 852 to: (1) assess the benefits of grass/legume mixtures over monocultures, (2) test the stability of mixtures and (3) evaluate the consistency of the observed patterns over broad environmental gradients. This paper compares the results from 3 Nordic sites using the same plant species: Korpa Experimental Station in Iceland, Lapland Research Station in Finland and Piteå in Sweden to investigate if compositional changes in mixtures are consistent across the sites.

Site Effects On The Composition Of Multi-Species Grass/Legume Mixtures During Sward Establishment, Rosemary P. Collins, M. Fothergill, John Connolly

IGC Proceedings (1977-2023)

Under the auspices of COST Action 852, a multi-site experiment investigated issues of community structure, function and their interrelationships in multi-species grass/legume mixtures (Collins et al., 2004; Sebastià et al., 2004). We describe the effects of 2 contrasting sites on forage yield and species composition during sward establishment.

Unplanned Fires And Sustainability Of A Semi-Arid Rangeland In South Africa, Hennie A. Snyman

IGC Proceedings (1977-2023)

Whether due to lightning or human negligence, large-scale unplanned fires affect large areas of the semi-arid southern African rangelands during the dormant winter (June-August) period (Everson 1999). These fires cause enormous fodder flow problems, and also influence ecosystem functioning (Snyman 2003). The short-term impact (2 years) of an unplanned fire on the sensitivity of above- and belowground productivity of a semi-arid rangeland was therefore investigated.

Effects Of Burning On Grassland Vegetation Cover On The Northeastern Side Of The Alborz Ranges In Iran, F. Amiri, M. R. Chaichi, A. Atrakchali

IGC Proceedings (1977-2023)

Golestan National Park is located on the northeastern side of the Alborz ranges, Golestan province, Iran. Because of the special vegetation cover and being located close to two wet and dry weather areas, this park is vulnerable to fire hazards. Between 1957 and 2004 more than 67 fires have been reported in the park. The international importance of the park requires a careful study on fire effects on vegetation cover, phytomass production, grass diversity and successional process after fires.

The Influence Of Tree Thinning And Subhabitat Differentiation On Panicum Maximum And Urochloa Mosambicensis Of A Bush Encroached Semi-Arid Savanna In South Africa, G. N. Smit

IGC Proceedings (1977-2023)

The productivity of grasses is most important for herbivores in extensive semi-arid savannas. In these areas an increase in woody plant abundance, commonly referred to as bush encroachment, suppresses grasses. This is the main reason why landowners often consider thinning or even total clearing of all woody plants. The aims of this study were to investigate the influence of different intensities of tree thinning and subhabitat differentiation on the grass layer of a semi-arid South African savanna.

The Effect Of Different Utilisation Methods On Composition Of Semi-Natural Grassland, J. Jančovič, L'. Vozár, L'. Jančovičová

IGC Proceedings (1977-2023)

There has been much research on application of mineral fertilisers to permanent grasslands to maximise production of above-ground phytomass (Folkman & Jančovič 1990), but the changes arising after exclusion of fertilisers have not been studied in Slovak Republic up to now despite current interest in low input ststems. This paper reports on the effects of cessation of fertiliser inputs for an eight-year period.

Impact Of The Agricultural Use On The Biodiversity Of A Festuca Rubra Meadow, I. Rotar, F. Păcirar, R. Vidican, N. Sima

IGC Proceedings (1977-2023)

Technological inputs into meadow ecosystems trigger significant changes in the sward. In this paper we present the effect of organic and mineral fertilisation on the biodiversity of a Festuca rubra meadow.