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Articles 18781 - 18810 of 294508

Full-Text Articles in Physical Sciences and Mathematics

Advanced Machine Learning Techniques For Cardiovascular Disease Risk Prediction, Godfred Ahenkroa Kesse Jan 2025

Advanced Machine Learning Techniques For Cardiovascular Disease Risk Prediction, Godfred Ahenkroa Kesse

Data Science and Data Mining

of mortality, necessitating advanced predictive models to aid early detection and prevention. This study explores the application of machine learning techniques, including Lo- gistic Regression, K-Nearest Neighbors (KNN), Random Forest, and XGBoost, to predict CVD risk using a dataset of 69,997 observations encompassing demographic, clinical, and lifestyle factors. Data preprocessing involved one-hot encoding of cat- egorical variables and scaling to ensure compatibility with all models. Model performance was evaluated using metrics such as accuracy, precision, recall, F1-score, and AUC-ROC. Among the models, XGBoost demonstrated the highest accuracy at 74%, leveraging its gradient-boosting framework to effectively handle feature interactions and imbalanced …

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Predicting Blood Glucose Levels: A Linear Regression Approach For Non-Invasive Monitoring, Godfred Ahenkroa Kesse Jan 2025

Predicting Blood Glucose Levels: A Linear Regression Approach For Non-Invasive Monitoring, Godfred Ahenkroa Kesse

Data Science and Data Mining

Accurate monitoring of blood glucose levels is vital for the management of diabetes, a chronic condition affecting millions worldwide. This study explores a linear regression approach to estimate glucose levels non-invasively using a dataset enriched with demographic, physiological, and sensor-based variables. Following rigorous data preparation, including normalization and encoding, a Box-Cox transformation was applied to address violations of regression assumptions, stabilizing variance and improving model validity. Stepwise selection and hypothesis testing were employed to refne the model, retaining signifcant predictors such as AGE, GENDER, HEARTRATE, and DIABETIC, while excluding variables like NIR Reading and LAST EATEN for their minimal contribution. …

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Handwritten Digit Recognition Using Naive Bayes And K-Nearest Neighbor Models, Godfred Ahenkroa Kesse Jan 2025

Handwritten Digit Recognition Using Naive Bayes And K-Nearest Neighbor Models, Godfred Ahenkroa Kesse

Data Science and Data Mining

This paper explores the performance of two fundamental classifcation algorithms. It uses Naive Bayes and K-Nearest Neighbors (KNN), framing it within the context of digit recognition of the MNIST dataset. The MNIST dataset has 70,00 grayscale images of handwritten digits, offering a standard for assessing classifcation models. This paper focuses on key performance metrics such as precision, accuracy, recall, and F1score to examine the effciency of each model. The results reveal that Naive Bayes has moderate accuracy and misclassifcations because of its notion of feature independence. The paper concludes that the KNN model performs better with the optimal k-value of …

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Variable Selection Using Lasso Regression, Godfred Ahenkroa Kesse Jan 2025

Variable Selection Using Lasso Regression, Godfred Ahenkroa Kesse

Data Science and Data Mining

This study employs Lasso regression to analyze highdimensional genetic data for predicting flowering time in maize, specifically Days to Anthesis (DtoA). Lasso, or Least Absolute Shrinkage and Selection Operator, is a form of linear regression that introduces an L1 penalty to the model, encouraging sparsity by shrinking some coefficients to zero. This attribute makes Lasso ideal for feature selection in large datasets, as it highlights the most influential predictors while discarding irrelevant variables. Unlike Ridge regression, which applies an L2 penalty to minimize the squared magnitude of coefficients, Lasso’s L1 penalty induces sparsity, providing a clearer interpretation of the selected …

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Classification And Evaluation Of Machine Learning Algorithms On The Mnist Dataset, Felix Yeboah Jan 2025

Classification And Evaluation Of Machine Learning Algorithms On The Mnist Dataset, Felix Yeboah

Data Science and Data Mining

This paper discusses the use of machine learning algorithms in classifying the MNIST handwritten dataset. The MNIST dataset consists of 28x28 grayscale handwritten images with 10 classes from 0 to 9. The dataset was normalized by scaling the pixel values to a range between 0 and 1 by dividing each pixel value by 255. We compare and evaluate the K-nearest Neighbor and Naive Bayes algorithm based on performance metrics such as accuracy, error rate, f1-score, and precision. The K-nearest Neighbor algorithm achieved better performance in all the evaluation criteria.

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2025 January 16 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jan 2025

2025 January 16 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

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Exhibit 2 “Basement Iswp” 122 W. Daly St. Butte, Mt 59701 January 16, 2025 Database Residential Identifier: R-00845, Butte-Silver Bow Department Of Reclamation And Environmental Services Jan 2025

Exhibit 2 “Basement Iswp” 122 W. Daly St. Butte, Mt 59701 January 16, 2025 Database Residential Identifier: R-00845, Butte-Silver Bow Department Of Reclamation And Environmental Services

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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Racial Disparities Of Type 2 Diabetes Through Exercise: The Multi-Ethnic Study Of Atherosclerosis, Tong Xia, Roch A. Nianogo, Qingzhao Yu, Tamara Horwich, Preethi Srikanthan, Kosuke Inoue, Matthew Allison, Zuo-Feng Zhang, Karol E. Watson, Liwei Chen Jan 2025

Racial Disparities Of Type 2 Diabetes Through Exercise: The Multi-Ethnic Study Of Atherosclerosis, Tong Xia, Roch A. Nianogo, Qingzhao Yu, Tamara Horwich, Preethi Srikanthan, Kosuke Inoue, Matthew Allison, Zuo-Feng Zhang, Karol E. Watson, Liwei Chen

School of Public Health Faculty Publications

Introduction: Persistent racial and ethnic disparities exist for Type 2 diabetes in the U.S. Racial and ethnic minorities have a higher risk of Type 2 diabetes, and studies suggest that they engage in less exercise than White population. This study examined whether and to what degree racial differences in Type 2 diabetes were explained by exercise. Methods: Adults aged 45–84 years without Type 2 diabetes at baseline (2000–2002) were included from the Multi-Ethnic Study of Atherosclerosis cohort and followed through 2020. Associations between race and Type 2 diabetes were examined using multivariable Cox proportional hazard regression. The effects of exercise …

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Nrdp Comments On Bp-Atlantic Richfield (Bp-Ar’S) Draft Materials Management Plan And Associated Documents At Butte Priority Soils Operable Unit Of The Silver Bow Creek/Butte Area Superfund Site, Jim Ford Jan 2025

Nrdp Comments On Bp-Atlantic Richfield (Bp-Ar’S) Draft Materials Management Plan And Associated Documents At Butte Priority Soils Operable Unit Of The Silver Bow Creek/Butte Area Superfund Site, Jim Ford

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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The Influence Of The Un Watercourses Convention On The Development Of A Policy Design In The Nile River Basin, Zienab Ali Abdelhady Jan 2025

The Influence Of The Un Watercourses Convention On The Development Of A Policy Design In The Nile River Basin, Zienab Ali Abdelhady

Theses and Dissertations

The adoption in 1997 of the United Nations Convention on the Law of the Non-navigational Uses of International Watercourses (UN Watercourses Convention or UNWC) marked a milestone in the codification and progressive development of international water law. Similarly, the signature in 2010 by the majority of the Nile Basin states of the Nile River Basin Cooperative Framework Agreement (CFA) was a major step towards a permanent legal and institutional framework as well as a significant shift from the currently applicable legal regime in the basin. The research concludes that the principles enshrined in the UNWC can assist future regional treaty …

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The Frequency Of Elliptic Curves Over $\Mathbb{Q}[I]$ With Fixed Torsion, Alan S. Zhao Jan 2025

The Frequency Of Elliptic Curves Over $\Mathbb{Q}[I]$ With Fixed Torsion, Alan S. Zhao

Rose-Hulman Undergraduate Mathematics Journal

Mazur\textsc{\char13}s Theorem states that there are precisely 15 possibilities for the torsion subgroup of an elliptic curve defined over the rational numbers. It was previously shown by Harron and Snowden that the number of isomorphism classes of elliptic curves of height up to $X$ that have a specific torsion subgroup $G$ is on the order of $X^{1/{d(G)}}$, for some positive $d(G)$ depending on $G$. We compute $d(G)$ for these groups over $\Qi$. Furthermore, in a collection of recent papers it was proven that there are 9 more possibilities for the torsion subgroup in the base field $\Qi$. We compute the …

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Aftdc 2025_02 Presentación: La Noción De Comunicación Transdisciplinaria En La Educación Por Marcos O. Cabobianco, Cristo Leon, Marcos O. Cabobianco Jan 2025

Aftdc 2025_02 Presentación: La Noción De Comunicación Transdisciplinaria En La Educación Por Marcos O. Cabobianco, Cristo Leon, Marcos O. Cabobianco

Trans-Disciplinary Communication

No abstract provided.

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Aftdc 2025_01 Kickoff: Welcome And Opening Remarks On Trans-Disciplinary Communication In Games And Education, Cristo Leon Jan 2025

Aftdc 2025_01 Kickoff: Welcome And Opening Remarks On Trans-Disciplinary Communication In Games And Education, Cristo Leon

Trans-Disciplinary Communication

This session sets the stage for the 2nd Annual Meeting of the Association for Trans-Disciplinary Communication (AFTDC). Join us as we introduce this year’s theme, "Trans-Disciplinary Communication for Games and Education," and highlight the importance of fostering innovative, collaborative approaches across disciplines. Opening remarks will outline the goals for the event, key initiatives, and opportunities for engagement, laying the foundation for meaningful discussions and shared learning throughout the day.

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Meditation In Qualitative Research For Bracketing And Beyond, Katalin Grajzel Jan 2025

Meditation In Qualitative Research For Bracketing And Beyond, Katalin Grajzel

Research Methods and Statistics: Graduate Student Scholarship

In this study, I recounted my experience using mantra meditation during a phenomenological study for the purposes of bracketing. The efficacy and purpose of bracketing have been debated from Husserl (1931), whose aimed was to achieve objectivity, to Heidegger (1962) who advocated for immersion of the researcher, through the French school (Merleau-Ponty, 1964) of middle ground, by whom bracketing was seen as the process to unearth and suspend biases for the better understanding of participants’ experiences (Arsel, 2017; Creswell & Creswell, 2017; Creswell & Poth, 2016; Fischer & Guzel, 2023). In this study, however, I propose another approach to bracketing …

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Coal Mining-Induced Composite Damage To Geological Bodies And Geological Guarantee Against Damage Reduction, Wang Shuangming, Sun Qiang, Hu Xin, Geng Jishi, Hou Enke, Wang Shengquan, Zhou Shutao, Shi Qingmin, Yuan Shihao, Chen Kai, Song Shijie Jan 2025

Coal Mining-Induced Composite Damage To Geological Bodies And Geological Guarantee Against Damage Reduction, Wang Shuangming, Sun Qiang, Hu Xin, Geng Jishi, Hou Enke, Wang Shengquan, Zhou Shutao, Shi Qingmin, Yuan Shihao, Chen Kai, Song Shijie

Coal Geology & Exploration

Objective and Background Coals have long served as a predominant energy source in China. With an increase in mining scale and intensity in recent years, the correlations between rocks, soils, hydrosphere, and ecological environment in coal mining areas have been strengthened. Given this, there is an urgent need to, from the perspective of Earth system science, understand the coupling relationships and chain characteristics among factors including the movement and deformations of surrounding rocks, rock bursts, coal and gas outbursts, water inrushes, ground subsidence, water and soil erosion, and damage to ecological environments, aiming to achieve safe, green coal mining. Methods …

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Fracture-Seepage Characteristic Zones Of The Overburden Of Extra-Thick Coal Seams: Evolutionary Patterns And Their Engineering Applications, Kong Xiangguo, Zhao Tianshuo, Lin Haifei, Zhao Pengxiang, Wang Xu, Cai Yuchu, Ji Pengfei, He Di, Li Ke, Xu Chuanyu Jan 2025

Fracture-Seepage Characteristic Zones Of The Overburden Of Extra-Thick Coal Seams: Evolutionary Patterns And Their Engineering Applications, Kong Xiangguo, Zhao Tianshuo, Lin Haifei, Zhao Pengxiang, Wang Xu, Cai Yuchu, Ji Pengfei, He Di, Li Ke, Xu Chuanyu

Coal Geology & Exploration

Objective and Methods Given that the overburden’s structure significantly influences pressure relief gas extraction, this study aims to explore the gas migration patterns of the overburden of thick coal seams during coal seam mining. To this end, this study analyzed the evolutionary patterns of the fracture morphology and seepage capacity of the overburden using physical similarity simulation experiments. Accordingly, this study investigated the mechanisms behind the evolution of fracture-seepage characteristic zones of the overburden of extra-thick coal seams and proposed a method for identifying fracture-seepage characteristic zones of the overburden. Using this method, this study conducted gas extraction along the …

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Experimental Study Of The Piezoelectricity Of Middle Pleistocene Loess In The Weibei Region, China, Jing Yanlin, Liu Jie, Liu Qingying, Duan Xiaoxiao, Xie Na, Yang Dengke Jan 2025

Experimental Study Of The Piezoelectricity Of Middle Pleistocene Loess In The Weibei Region, China, Jing Yanlin, Liu Jie, Liu Qingying, Duan Xiaoxiao, Xie Na, Yang Dengke

Coal Geology & Exploration

Objective Quartz, the piezoelectric material discovered the earliest, has found widespread applications in industry, military fields, and daily life due to its piezoelectricity. The widely distributed loess worldwide is composed primarily of quartz, accounting for 37.0% to 69.9%. However, there is a lack of studies on the piezoelectricity of loess both domestically and internationally. Methods This study investigated the ${\mathrm{Q}}_2^{{\mathrm{eol}}} $ loess from the Weibei Loess Tableland in Shaanxi Province as an example to explore the piezoelectricity of loess. The piezoelectric coefficient of the loess was measured, and its piezoelectric voltage under the action of static loading and vibration was …

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Deformations And Seepage-Induced Erosion Of Fractured Rocks In Fault Under Confined Settings, Sun Wenbin, Tian Dianjin, Ma Cheng, Xue Yanchao, Yang Can, Zhu Kaipeng Jan 2025

Deformations And Seepage-Induced Erosion Of Fractured Rocks In Fault Under Confined Settings, Sun Wenbin, Tian Dianjin, Ma Cheng, Xue Yanchao, Yang Can, Zhu Kaipeng

Coal Geology & Exploration

Objective Most of the mining areas in China have entered the deep mining stage. In this case, the risks of mine water inrushes increase significantly due to the complex deep hydrogeological conditions, a significant increase in the number of hidden disaster-causing factors, and the existence of faults. Methods Using a deformation-seepage experiment system for fractured rocks, this study investigated the characteristics of compressive deformations and seepage-induced erosion of fractured rocks in faults. By analyzing the impacts of particle-size distribution combinations, saturation state, and seepage pressure, on the deformation-permeability characteristics of fractured rocks under confined axial compression, this study investigated the …

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An Intelligent Lithology Identification Method For Sandstone And Mudstone Strata And Its Applications: A Case Study Of The Jurassic Strata In The Lunnan Area, Xinjiang, China, Cai Ming, Zhou Qingwen, Yang Cong, Chen Feng, Wu Dong, Lin Wang, Zhang Chengguang, Zhang Yuanjun, Miao Yuxin Jan 2025

An Intelligent Lithology Identification Method For Sandstone And Mudstone Strata And Its Applications: A Case Study Of The Jurassic Strata In The Lunnan Area, Xinjiang, China, Cai Ming, Zhou Qingwen, Yang Cong, Chen Feng, Wu Dong, Lin Wang, Zhang Chengguang, Zhang Yuanjun, Miao Yuxin

Coal Geology & Exploration

Objective Lithology identification lays the foundation for fine-scale reservoir evaluation. However, traditional identification methods generally utilize the interactive relationships between only 2‒3 logging parameters, suffering from low utilization rates of logging information and low identification accuracy for strata with small differences in logging responses. This seriously restricts the effects of old well reexamination. The efficient, intelligent CatBoost classification algorithm can fully mine the correlations between multi-source logging information and lithology. Methods This study investigated the Jurassic sandstone and mudstone reservoirs in the Lunnan area, Xinjiang, China. Using five logging parameters determined through sensitivity analysis, i.e., natural gamma-ray value, spontaneous potential, …

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A Dehazing And Enhancement Algorithm For Heterogeneous Images Of Underground Mining Environments In Coal Mines, Zhang Xuhui, Xie Yanbin, Yang Wenjuan, Zhang Chao, Wan Jicheng, Dong Zheng, Wang Yanqun, Jiang Jie, Li Long Jan 2025

A Dehazing And Enhancement Algorithm For Heterogeneous Images Of Underground Mining Environments In Coal Mines, Zhang Xuhui, Xie Yanbin, Yang Wenjuan, Zhang Chao, Wan Jicheng, Dong Zheng, Wang Yanqun, Jiang Jie, Li Long

Coal Geology & Exploration

Objective In coal mines, the uneven distribution of dust haze and complex illumination conditions caused by underground coal mining and dust removal lead to blurred video images, as well as the loss of information and details. Hence, this study proposed a dehazing and enhancement algorithm for heterogeneous images of underground mining environments. Methods Initially, hazy images were segmented into zones with different brightness values, for which the average ambient light intensity of global dark channels was calculated. The calculation results were integrated through weighting with the ambient light of local bright channels, which was obtained using adaptive gamma correction and …

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An Analytical Method For The Desorption Superposition Effect In Commingled Production Of Coalbed Methane And Its Application: A Case Study Of The Xiaotun Mine Field In Western Guizhou Province, China, Guo Chen, Ji Yan, Zhao Chenyi, Lu Lingling, Yu Xinhang, Gao Junzhe, Li Houqiang, Zhang Xuyang, Wang Xiang, He Hongbin, Zhang Runhan Jan 2025

An Analytical Method For The Desorption Superposition Effect In Commingled Production Of Coalbed Methane And Its Application: A Case Study Of The Xiaotun Mine Field In Western Guizhou Province, China, Guo Chen, Ji Yan, Zhao Chenyi, Lu Lingling, Yu Xinhang, Gao Junzhe, Li Houqiang, Zhang Xuyang, Wang Xiang, He Hongbin, Zhang Runhan

Coal Geology & Exploration

Objective The commingled production of coalbed methane (CBM) serves as a significant means to increase single-well production. However, production practices reveal that the commingled production of CBM exhibits complex and varied effects and controlling factors, facing technical challenges of identifying gas-producing contributions, predicting gas-producing potential, and optimizing pay interval combinations. The superposition of desorption for gas production among different coal seams determines whether high CBM production can be achieved using commingled production. Methods This study proposed an analytical method for the desorption superposition effect in the commingled production of CBM, involving determining desorption sequences, analyzing the superposition of desorption intervals …

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Optical-Electrical-Acoustic Wave Multiparameter Response Characteristics Of Typical Rocks In Coal-Bearing Strata Throughout The Loading Process, Zhang Pingsong, Liu Chang Jan 2025

Optical-Electrical-Acoustic Wave Multiparameter Response Characteristics Of Typical Rocks In Coal-Bearing Strata Throughout The Loading Process, Zhang Pingsong, Liu Chang

Coal Geology & Exploration

Objective The deformations and rupture of rocks under loading will cause potential changes in parameters. Dynamic parameter capture assists in characterizing the generation, propagation, and closure processes of fractures, serving as a significant method for assessing rock quality. Methods Using a multiparameter test system, this study synchronously acquired strain measured using distributed optic fibers, electrode current, and compressional wave (P-wave) velocities of rock specimens under uniaxial loading. Accordingly, this study determined strength vs. parameter characteristic relationship graphs and parametric tomography results, finely describing the multiparameter spatiotemporal evolutionary characteristics of three typical rocks (i.e., sandstone, limestone, and mudstone) throughout the loading …

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A U-Net-Based Denoising Method For Semi-Airborne Transient Electromagnetic Data And Its Application, Liu Dong, Feng Hao, Wang Yongxin, Zhou Xiaosheng, Yao Yuhong, Sun Huaifeng Jan 2025

A U-Net-Based Denoising Method For Semi-Airborne Transient Electromagnetic Data And Its Application, Liu Dong, Feng Hao, Wang Yongxin, Zhou Xiaosheng, Yao Yuhong, Sun Huaifeng

Coal Geology & Exploration

Objective and Methods The semi-airborne transient electromagnetic (SATEM) method, an efficient geophysical exploration technique, has been extensively applied to mineral resource exploration, groundwater surveys, and geothermal resource surveys. However, the collected data are frequently susceptible to noise interference, significantly affecting the accuracy of subsequent data processing and interpretation. To address issues such as residual noise and the loss of effective signals, enhance denoising effects, and reduce the influence of subjective factors, this study proposed a denoising method for SATEM data based on the U-Net deep learning architecture (also referred to as the U-Net-based method) by applying U-Net to SATEM data …

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Wind And Topography Underlie Correlation Between Seasonal Snowpack, Mountain Glaciers, And Late-Summer Streamflow, Elijah N. Boardman, Andrew G. Fountain, Joseph W. Boardman, Thomas H. Painter, Evan W. Burgess, Laura Wilson, Adrian A. Harpold Jan 2025

Wind And Topography Underlie Correlation Between Seasonal Snowpack, Mountain Glaciers, And Late-Summer Streamflow, Elijah N. Boardman, Andrew G. Fountain, Joseph W. Boardman, Thomas H. Painter, Evan W. Burgess, Laura Wilson, Adrian A. Harpold

Geology Faculty Publications and Presentations

In a warming climate, net mass loss from perennial snow and ice (PSI) contributes a temporary source of unsustainable streamflow. However, the role of topography and wind in mediating the streamflow patterns of deglaciating watersheds is unknown. We conduct lidar surveys of seasonal snow and PSI elevation change for five adjacent watersheds in the Wind River Range, Wyoming (WRR). Between 2019 and 2023, net mass loss from PSI is equivalent to ~10-36% of August-September streamflow. Across 338 manually classified PSI features >0.01 km2, glaciers contribute 68% of the total mass loss, perennial snowfields contribute 8%, rock glaciers contribute 1%, buried …

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Model-Theoretic Properties Of Nilpotent Groups And Lie Algebras, Christian D'Elbée, Isabel Müller, Nicholas Ramsey, Daoud Siniora Jan 2025

Model-Theoretic Properties Of Nilpotent Groups And Lie Algebras, Christian D'Elbée, Isabel Müller, Nicholas Ramsey, Daoud Siniora

Faculty Journal Articles

We give a systematic study of the model theory of generic nilpotent groups and Lie algebras. We show that the Fraïssé limit of 2-nilpotent groups of exponent p studied by Baudisch is 2-dependent and NSOP1. We prove that the class of c-nilpotent Lie algebras over an arbitrary field, in a language with predicates for a Lazard series, is closed under free amalgamation. We show that for 2c.

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The Role Of Α-Inequalities In Examining The Singular Version Of The Big Bang Model, Samane Ijadi, S. Mansour Vaezpour, Mehdi Shabibi, Shahram Rezapour Jan 2025

The Role Of Α-Inequalities In Examining The Singular Version Of The Big Bang Model, Samane Ijadi, S. Mansour Vaezpour, Mehdi Shabibi, Shahram Rezapour

Turkish Journal of Mathematics

In this article, by extending Friedmann's equation, we propose a singular fractional differential system for the Big Bang model. In this model, the rate of increase in the size of the universe tends to infinity at time near to zero and causes the emergence of a singular differential equation,which physically justifies the near-infinity energy of the universe in the near-zero volume of the universe in the early moments of the Big Bang. Then, we investigate this type of strong singular boundary value problem, by using $\alpha$-inequalities. In the sequel, some examples, describe the main results. Moreover, we present numerical and …

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China’S Cbm Exploration And Production And Associated Technological Advancements: A Review And Reflections, Ye Jianping Jan 2025

China’S Cbm Exploration And Production And Associated Technological Advancements: A Review And Reflections, Ye Jianping

Coal Geology & Exploration

Objective and Methods Based on extensive scientific and technical literature and technical data on coalbed methane (CBM) exploration and production projects, this study conducted a comparative analysis of the development process and latest advances in China’s critical technologies for CBM exploration and production and reviewed the CBM exploration and production history of this country over the past three decades. Accordingly, this study discussed the theoretical and technical challenges in CBM exploration and production and proposed future development directions. Advances The results indicate that the insights into conversion between adsorbed and free deep CBM prove to be a significant theoretical understanding. …

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Critical Technologies And Geology-Engineering Integration Practices For Deep Cbm Production In The Yanchuannan Cbm Field, Chen Zhenlong, Wang Yunhai, Liu Xiao, Cui Bin, Yang Song, Li Xin, Fang Qilong Jan 2025

Critical Technologies And Geology-Engineering Integration Practices For Deep Cbm Production In The Yanchuannan Cbm Field, Chen Zhenlong, Wang Yunhai, Liu Xiao, Cui Bin, Yang Song, Li Xin, Fang Qilong

Coal Geology & Exploration

Objective and Methods This study introduces the adjustments for coalbed methane (CBM) production in the Yanchuannan CBM field‒the first deep CBM field in China. Deep CBM production in this CBM field faces challenges including strong heterogeneity of reservoirs, single arrangement mode of production well patterns, low applicability of conventional hydraulic fracturing, excessively long conventional production cycles, and a high proportion of inefficient wells. To address these challenges, a production capacity construction model for efficient deep CBM production of the field was developed through in-depth geology-engineering integration. Results and Conclusions The results indicate that the production capacity construction process of the …

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Connotation, Research Status, And Development Directions Of Clean Coal Geology In China, Tang Yuegang, Wang Shaoqing, Wang Xiaoshuai, Guo Xin, Wang Yafeng, Xue Liping, Harold H. Schobert Jan 2025

Connotation, Research Status, And Development Directions Of Clean Coal Geology In China, Tang Yuegang, Wang Shaoqing, Wang Xiaoshuai, Guo Xin, Wang Yafeng, Xue Liping, Harold H. Schobert

Coal Geology & Exploration

Objective The exploration and assessment of low-carbon, zero-emission, and maximized utilization of coal resources, emerge as a focus of coal geology in the 21st century. [Research Advances] Based on the research content of coals and coal geology, along with the domestic and international development trends of clean coal technology (CCT), this study defines clean coal geology in the broad and narrow sense. Clean coal geology in the narrow sense focuses on the geological and geochemical issues related to efficiency enhancement and emission reduction in coal processing and utilization. In contrast, clean coal geology in the broad sense emphasizes …

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Asymptotic Behavior Of The Kirchhoff Index For Square Lattice With Boundary Conditions, Fati̇h Ecevi̇t, Arzu Boysal Jan 2025

Asymptotic Behavior Of The Kirchhoff Index For Square Lattice With Boundary Conditions, Fati̇h Ecevi̇t, Arzu Boysal

Turkish Journal of Mathematics

We determine leading asymptotic behavior of the Kirchhoff index for the square lattice under free, cylindrical and toroidal boundary conditions. Our results provide correct forms of the eleven false theorems/results published in the following papers: L. Ye, On the Kirchhoff index of some toroidal lattices, Linear Multilinear Algebra, 59:6 (2011), 645--650; J.-B. Liu, X.-F. Pan, J. Cao, X. Huang, The Kirchhoff index of toroidal meshes and variant networks, Math. Probl. Eng., Article ID 286876, 8 pages (2014); J.-B. Liu, X.-F. Pan, A unified approach to the asymptotic topological indices of various lattices, Appl. Math. Comput., 270 (2015), 62--73.

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