Physical Sciences and Mathematics Commons^™

Study On Compliance Assessment Of Ship Exhaust Emissions In China's Eca (Emission Control Area), Yahan Hu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Pollution Causes And Prevention Measures In Bohai Sea, Yiqiao Wang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Damage Mechanism And Countermeasures Of Reservoir With Abnormal Pickup Of Cbm Flow Pressure In Well, Jia Huimin, Hu Qiujia, Qi Kongjun, Qin Mengfu, Mao Chonghao, Zhang Guangbo

Coal Geology & Exploration

The reasonable control of the casing pressure and the bottom-hole pressure and the reasonable depressurization of reservoir pressure is the key technology for the CBM development. The pickup of the bottom-hole flow pressure(BHFP) will restrain CBM' desorption, lead to reservoir permeability damage and reduce the production of CBM wells. Based on production practice of Fanzhuang block in Qinshui basin, this paper puts forward the cause of a CBM abnormal well type, pickup of the BHFP, clarifies the damage mechanism of the pickup of the BHFP through theoretical research and field data analysis, and puts forward the evaluating method of the …

Analysis Of Reservoir Conditions Of Shale Gas In Middle Permian Wenbishan Formation In Fujian Province, Chen Quanlin

Coal Geology & Exploration

This study is performed on the geological conditions of shale gas in Middle Permian Wenbishan Formation in Fujian Province. It is based on organic geochemistry, rock minerals and reservoir physical property after geology survey and drilling. The results indicate that kerogen is Ⅲ-type, organic carbon is usually between 1% to 2%, R_ran is between 3.76% to 4.91% in the shale of Wenbishan Formation, and the shale is in the mature stage. The content of brittle minerals is generally low. The shale has medium porosity and extremely low permeability, the micro and meso-pores constitute the major space for gas adsorption. …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Numerical Simulation On Mechanism Of Thrust Fault Reactivation During Mining, Min Feihu, Xiang Biwei, Liu Hui, Zhu Xiaojun

Coal Geology & Exploration

It is a hot issue in mine disaster research about the activation of faults during the process of coal mining and excavation. In order to reveal the influence of coal mining on fault activation under different fault dip conditions, Xinji No.2 mine in Huainan coalfield was taken as an example, and numerical simulation with FLAC^3D was used to systematically study the dynamic activation law of thrust faults during mining beside the faults, and to clarify the relationship among fault activation position and fault dip angle and excavated distance of working face. The results show that the fault activation is …

Accurate Test Technology And Device For Coal Seam Gas Content In Long Boreholes In Underground Coal Mines, Sun Siqing, Zhang Qun, Long Weicheng, Zheng Kaige, Hei Lei

Coal Geology & Exploration

In order to get actual gas content of underground coal mine during large-scale advanced detection, the sealed coring method for gas content was proposed. The sealed coring device of "three-cylinders, single motion and ball valve sealing" suitable for accurate test of gas content of long boreholes in underground coal mines was designed and trial-produced, the outer diameter of the device is 89 mm, and the diameter of the coal core can reach 38 mm, the pressure holding capacity of the sealed coring device is above 11 MPa, which satisfies the requirement of sealing sampling for the determination of coal seam …

Coal Control Factors Of Middle Jurassic Shimengou Formation In Beidatan Area, East Part Of The Northern Qaidam Basin, Peng Minghong, Tian Jingchun, Zhang Xiang, Chen Lei, Zeng Jianqiang, Wang Suying

Coal Geology & Exploration

The key of the coal exploration in Beidatan area of Qinghai Province is the coal accumulation environment in the sedimentary period and the control of coal seam occurrence by tectonic action before and after sedimentation. To identify Shimengou Formation coal controlling factors in Beidatan area, east part of the northern Qaidam basin, effectively guide the coal exploration of the coal bearing area, through field outcrops, drilling, geophysical prospecting and other geological information system, based on the analysis of coal accumulating environment and structural function of Shimengou Formation in Beidatan area, the control factors of coal were deeply discussed from coal …

Water Inflow Law Of The First Working Face Based On Water Pre-Draining From Roof, Li Yongtao, Yang Jian

Coal Geology & Exploration

In order to establish water control technology system in Inner Mongolia-Shaanxi contiguous area, we carried out some researches(e.g. overburden failure law, hydrogeological conditions, prediction of water inflow and pre-drainage of roof water) in Nalinhe No.2 coal mine. The results showed that three methods(i.e. coring, drilling fluid leakage observation and borehole color TV detection) were used to explore water-conducting fracture zone(103.23 m), and the ratio of the height of the fractured zone to the mining height was 18.8. Water-conducting fracture zone could connect three aquifers, and the Zhiluo Formation bottom aquifer was the main aquifer threatening safety mining. Water inflow and …

Influencing Factors Of Surface Gas Extraction Effect In Wangpo Minefield Of Jincheng Mining Area, Du Zhiqiang

Coal Geology & Exploration

The effect of surface gas extraction in Wangpo minefield of Jincheng mining area is poor. In order to find out the causes and to guide the construction of future surface gas extraction, the occurrence conditions of CBM resources in the study area were analyzed and compared with those of adjacent Chengzhuang minefield where the extraction effect is good, the quality of the produced water was tested, at the same time the fracture forms were observed underground. The comprehensive analysis indicated that the abundance of coal gas resources and the reservoir conditions were the major intrinsic basic factors influencing the gas …

Study On Uniaxial Compression Mechanical Properties Of Sandstone With Different Moisture Content And Wave Velocity Method, Duan Tianzhu, Ren Yaping

Coal Geology & Exploration

In order to investigate the mechanical properties and damage of sandstone under different uniaxial compression, the static uniaxial compression tests of five sandstones with different moisture content were carried out, and the physical and mechanical parameters were obtained. And the wave velocity of the sandstone samples with different moisture content were measured by ultrasonic detector. Then the sandstone was loaded to 80% peak intensity and then unloaded to 0. The acoustic wave velocity of sandstone was measured at this time. The damage was determined by acoustic wave method. The results show that the peak strength of sandstone under uniaxial compression …

Technology And Application Of Indirect Fracturing In Cbm Vertical Well Of Broken And Soft Coal Seam With Low Permeability, Zhou Jiajia

Coal Geology & Exploration

In order to solve the problems of pulverized coal output and fracturing fracture not easy to extend during fracturing operation in the broken and soft coal seam with low permeability, the adaptability and fracturing fracture distribution of CBM during indirect fracturing are studied by means of in-situ stress and numerical simulation, and the engineering practice of indirect fracturing has been tested in Hongshandian mining area of Hunan Province. The results show that indirect fracturing can effectively improve the fracturing effect of the broken and soft coal seam with low permeability, and increase the fracture length. When the roof and floor …

Analysis And Application Of Key Influencing Factors Of Cbm Well Fracturing Effects In Shizhuang Area, Qinshui Basin, Xue Haifei, Zhu Guanghui, Wang Wei, Lu Xiaoxia, Wang Minghao, Wang Yanbin

Coal Geology & Exploration

CBM fracturing effect has many influencing factors. Development effect with the same technology is different in different area. Based on a large amount of geological and engineering data in Shizhuang block, it was found that high geo-stress affects fracture extension and support in CBM fracturing, and difference between horizontal stress affects fracture direction and morphology. Coal seam with poor coal structure can produce large amount of gum during fracturing, which will block the diversion channel and result in poor fracturing effect. Engineering factors affecting fracturing effect mainly include the fracturing fluids performance, displacement, prepad fluid proportion and hole enlargement ratio. …

Corrosion Behavior Analysis Of Sucker Rod For Coalbed Methane Wells In The Eastern Block Of Ordos Basin, Pang Bin, Wang Hanxiang, Lan Wenjian

Coal Geology & Exploration

In order to make clear the corrosion rule of sucker rod for coalbed methane wells in the eastern block of Ordos basin, the paper summarizes the corrosion types and corrosion intensities of the sucker rod, based on the test of produced gas, produced water, corrosion products and weight loss of sucker rod. The paper analyzes the effect of different drainage stages, coal seam and mineralization degree of water on the corrosion. The results of the research indicate that corrosion is mainly caused by CO₂ and H₂S originated from No.5 coal seam and No.11 coal seam. The corrosion …

Shale Gas Potential Of Yanguanjie Formation And Longtan Formation In Central And Southeastern Hunan Province, Cao Taotao, Deng Mo, Liu Hu, Huang Yanran, Stefan Andrew Hurssthouse

Coal Geology & Exploration

In order to reveal the shale gas potential and exploration direction of the marine-continental transitional shale in central and southeastern Hunan, samples were collected from the Lower Carboniferous Yanguanjie Formation and Upper Permian Longtan Formation, measurements were conducted on TOC, R_ran, kerogen carbon isotope, maceral composition, X-ray diffraction, scanning electron microscopy, porosity, permeability and methane sorption capacity. The results indicate that Yanguanjie Formation and Longtan Formation shale are at the mature stage, and mainly dominated by type Ⅲ kerogen. The Longtan shale generally has higher TOC content, while Yanguanjie shale has usually low TOC content. The minerals are …

Application Of Seismic Exploration Technology In Forecasting Unconventional Gas Enrichment Area Of Coal Measures, Wang Shuwei

Coal Geology & Exploration

For forecasting unconventional gas enrichment area in coal measures of eastern Ordos basin, seismic exploration was used to forecast the gas in this new field. First of all, it took the post-stack impedance inversion to forecast the lithology of the reservoir, it can get the number of sample points from the impedance threshold, and get the thickness of time by cal-culating the sampling rate, after that it can get the strata thickness by multiplying the thickness of time and the velocities of strata; second, it took the pre-stack AVO inversion to forecast the lithology gas-bearing properties of the reservoir, based …

A Method Of Random Noise Suppression Based On Compressed Sensing, Yang Liangang, Li Lingyun, Yang Yumei, Qu Yuanji, Yan Ke

Coal Geology & Exploration

With the development of high precision seismic exploration technology, the use of high fidelity methods to improve the SNR of seismic data becomes the key to denoising. Curvelet threshold method can effectively suppress random noise, but at the same time the method is easy to produce pseudo Gibbs shock phenomenon, resulting in local distortion of the signal, thus affecting the processing effect. To solve this problem, a method of seismic signal denoising based on compressing sensing(CS) is presented in this paper. The method uses the difference between sparse representation of random noise and effective signal in curvelet sparse domain to …

Structural Optimization And Simulation Analysis Of High Reliability Wire-Line Coring Drilling Tools For Submarine Drilling Rigs, Wang Jialiang, Peng Fenfei, Wan Buyan, Zhou Yun

Coal Geology & Exploration

In order to improve the working reliability of wire-line coring drilling tools used in submarine drilling rigs, based on the particularity of submarine environment, from the aspect of improvement of the single action performance of the single action mechanism and the working reliability of the suspension mechanism, the structural optimization of the single action mechanism was carried out, the numerical simulation analysis of the suspension mechanism was conducted by using ABAQUS simulation. The results show that the improved bearing assembly structure can restrain sea water corrosion, improve the centering effect of arbor and enhance the flexibility of bearing assembly. The …

A Pipeline Robot Detection Image Enhancement Method Based On Image Fusion And Improved Threshold, Yuan Mingdao, Tan Cai, Li Yang, Xu Yunqian, Zhang Xuhui, Yang Jingxue

Coal Geology & Exploration

Pipeline robot detection technology can quickly, accurately and intuitively identify the structure and hidden functional troubles of pipeline. However, due to the restriction of the pipeline environment, the detected images have problems such as uneven illumination, low contrast and blurred details. Therefore, an enhancement technique for detected image of pipeline robot is proposed. First, the contrast limited adaptive histogram equalization(CLAHE) and homomorphic filtrate(HF) are applied to deal with the problem of uneven illumination and low contrast, and the result images of the two methods are fused. Secondly, the fusion images are transformed by the Nonsubsampled Contourlet Transform(NSCT), and the improved …

“A Thousand Words”: How Shannon Entropy Perspective Provides Link Among Exponential Data Growth, Average Temperature Of The Earth, Declining Earth Magnetic Field, And Global Consciousness, Victor Christianto, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

The sunspot data seems to indicate that the Sun is likely to enter Maunder Minimum, then it will mean that low Sun activity may cause low temperature in Earth. If this happens then it will cause a phenomenon which is called by some climatology experts as “The Little Ice Age” for the next 20-30 years, starting from the next few years. Therefore, the Earth climate in the coming years tend to be cooler than before. This phenomenon then causes us to ask: what can we do as human being in Earth to postpone or avoid the worsening situation in terms …

A Geometric Generalizaion Of The Planar Gale-Nikaidô Theorem, Eduardo C. Balreira

Eduardo Cabral Balreira

The Gale-Nikaidô Theorem establishes global injectivity of maps defined over rectangular regions provided the Jacobian matrix is a P-matrix. We provide a purely geometric generalization of this result in the plane by showing that if the image of each edge of the rectangular domain is realized as a graph of a function over the appropriate axis, then the map is injective. We also show that the hypothesis that the Jacobian matrix is a P-matrix is simply one way to analytically check this geometric condition.

Global Stability Of Higher Dimensional Monotone Maps, Eduardo C. Balreira, Saber Elaydi, Rafael Luis

Eduardo Cabral Balreira

We develop a notion of monotonicity for maps defined on Euclidean spaces R^k₊, of arbitrary dimension k. This is a geometric approach that extends the classical notion of planar monotone maps or planar competitive difference equations. For planar maps, we show that our notion and the classical notion of monotonicity are equivalent. In higher dimensions, we establish certain verifiable conditions under which Kolmogorov monotone maps on R^k₊ have a globally asymptotically stable fixed point. We apply our results to two competition population models, the Leslie–Gower and the Ricker models of two- and three-species. It …

The History Of Mathematics: A Source-Based Approach, Volume 1 (Book Review), Calvin Jongsma

Faculty Work Comprehensive List

Reviewed Title: The History of Mathematics: A Source-based Approach, Volume 1 by June Barrow-Green, Jeremy Gray, and Robin Wilson. Providence : American Mathematical Society, 2019. 488 pp. ISBN: 9781470443528.

Pi+ Cross Section On Argon For The Lariat Experiment, Gregory Pulliam

Dissertations - ALL

LArIAT (Liquid Argon in a Testbeam) was a LArTPC experiment exposed to a charged-particle beam at the test-beam facility at Fermi National Accelerator Laboratory. This analysis measures the $\pi^+$-Ar cross section over an interacting energy range of 50-1100 MeV, accounting for background species and reconstruction effects. This is the first such measurement of this process. The result can be useful in tuning simulations for future liquid argon experiments such as DUNE and SBN.

Modeling The Defects That Exists In Crystalline Structures, Kiet A. Tran

REU Final Reports

This paper focuses on modeling defects in crystalline materials in one-dimension using field dislocation mechanics (FDM). Predicting plastic deformation in crystalline materials on a microscopic scale allows for the understanding of the mechanical behavior of micron-sized components. Following Das et al (2013), a one dimensional reduction of the FDM model is implemented using Discontinuous Galerkin method and the results are compared with those obtained from the finite difference implementation. Test cases with different initial conditions on the position and distribution of screw dislocations are considered.

Innovations In (U–Th)/He, Fission Track, And Trapped Charge Thermochronometry With Applications To Earthquakes, Weathering, Surface‐Mantle Connections, And The Growth And Decay Of Mountains, Alexis K. Ault, Cécile Gautheron, Georgina E. King

Geosciences Faculty Publications

A transformative advance in Earth science is the development of low‐temperature thermochronometry to date Earth surface processes or quantify the thermal evolution of rocks through time. Grand challenges and new directions in low‐temperature thermochronometry involve pushing the boundaries of these techniques to decipher thermal histories operative over seconds to hundreds of millions of years, in recent or deep geologic time and from the perspective of atoms to mountain belts. Here we highlight innovation in bedrock and detrital fission track, (U–Th)/He, and trapped charge thermochronometry, as well as thermal history modeling that enable fresh perspectives on Earth science problems. These developments …

Sevucas: A Novel Gis-Based Machine Learning Software For Seismic Vulnerability Assessment, Saro Lee, Mahdi Panahi, Hamid Reza Pourghasemi, Himan Shahabi, Mohsen Alizadeh, Ataollah Shirzadi, Khabat Khosravi, Assefa M. Melesse, Mohamad Yekrangnia, Fatemeh Rezaie, Hamindreza Moeini, Binh Thai Pham, Baharin Bin Ahmad

Department of Earth and Environment

Since it is not possible to determine the exact time of a natural disaster’s occurrence and the amount of physical and financial damage on humans or the environment resulting from their event, decision-makers need to identify areas with potential vulnerability in order to reduce future losses. In this paper, a GIS-based open source software entitled Seismic-Related Vulnerability Calculation Software (SEVUCAS), based on the Step-wise Weight Assessment Ratio Analysis (SWARA) method and geographic information system, has been developed to assess seismic vulnerability by considering four groups of criteria (i.e., geotechnical, structural, socio-economic, and physical distance to needed facilities and away from …

Improving The Sensitivity Of Advanced Ligo Through Detector Characterization, Derek Davis

Dissertations - ALL

This dissertation focuses on the impact of detector characterization work on searches for gravitational waves from compact binary coalescences (CBCs) in Ad- vanced LIGO’s second observing run (O2). This observing run started on November 30, 2016, and lasted until August 25, 2017, and resulted in the identification of 8 unambiguous gravitational-wave signals, including the first observation of a binary neutron star merger. The role of detector characterization is to leverage knowledge of both the interferometers and the data in order to improve aLIGO’s ability to observe gravitational-waves.

I focus on the construction of the O2 noise subtracted data set that …

The Shape Of Soft Matter: Geometry And Defects, Francesco Serafin

Dissertations - ALL

How does shape emerge at macroscopic scales from the spontaneous self-organization of building blocks at smaller scales? In this thesis, I will address this question in the context of closed soft two-dimensional membranes with internal order. Soft matter represents a good arena to identify simple universal mechanisms for shape selection. In fact, a distinctive property of soft materials is that they can undergo dramatic changes in geometric conformation at relatively low energetic cost. Thus, shape itself becomes a statistically fluctuating degree of freedom, and in some cases it can be found as the ground state of an appropriate free energy …

Synergistic Development Of Shipping Center And Technological Innovation, Mingze Du

World Maritime University Dissertations

No abstract provided.