Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 29911 - 29940 of 195926

Full-Text Articles in Engineering

Knn Fault Detection Based On Reconstruction Error And Multi-Block Modeling Strategy, Jing Zheng, Weili Xiong, Xiaodong Wu Jan 2023

Knn Fault Detection Based On Reconstruction Error And Multi-Block Modeling Strategy, Jing Zheng, Weili Xiong, Xiaodong Wu

Journal of System Simulation

Abstract: For the fault monitoring algorithm based on k-nearest neighbor (kNN), the abnormal information that caused the fault is easy to be overwhelmed by the normal operating condition information, which leads to the problem of untimely fault detection and low alarm rate. A kNN fault monitoring method based on reconstruction error is proposed using auto-encoder and multi-block modeling strategy. The method uses the normal working condition data set to train the auto-encoder model, and extracts the reconstruction error based on the model to solve the problem that abnormal information is easy to be overwhelmed. Further considering the fault characteristics such …


Performance Of Rubberized Concrete And The Effect Of Temperature And Stainless Steel Fibers, Ayman El-Zohairy, Matthew Sanchez, Bahram Abediniangerabi, Perry Moler Jan 2023

Performance Of Rubberized Concrete And The Effect Of Temperature And Stainless Steel Fibers, Ayman El-Zohairy, Matthew Sanchez, Bahram Abediniangerabi, Perry Moler

Faculty Publications

Rubberized concrete is widely used in construction by utilizing the advantages of partially replacing fine or coarse aggregate with rubber to enhance several properties of concrete and provide an environmentally friendly solution. This paper experimentally explores the influence of utilizing crumb rubber (CR) as an alternate coarse aggregate in concrete. Concrete specimens were prepared with different percentages of rubber (0%, 5%, 10%, 15%, and 20%). Additionally, other parameters, such as freezing–thawing cycles, temperature, and stainless steel fibers (SSFs), were investigated. The workability of fresh concrete and the compression properties of hardened concrete were examined. Reductions in the mechanical properties of …


Chameleon Swarm Algorithm For Segmental Variation Learning Of Population And S-Type Weight, Damin Zhang, Yi Wang, Linna Zhang Jan 2023

Chameleon Swarm Algorithm For Segmental Variation Learning Of Population And S-Type Weight, Damin Zhang, Yi Wang, Linna Zhang

Journal of System Simulation

Abstract: It is the best choice for intelligent algorithms to be applied to specific fields to explore strong searching ability, good reliability and stability.In this paper, aiming at the defects of chameleon swarm algorithm, such as unstable solution, low convergence accuracy and unbalanced search and development, a chameleon swarm algorithm (RMSCSA) based on population diversity segmental mutation learning and S-type weight is proposed. The refraction mirror learning strategy (RML) is introduced to make the chameleon more consistent with the observation in nature and enhance its diversity. The introduction of segmental variation of population diversity can keep the individuals with poor …


Large-Scale Multi-Objective Natural Computation Based On Dimensionality Reduction And Clustering, Weidong Ji, Yuqi Yue, Xu Wang, Ping Lin Jan 2023

Large-Scale Multi-Objective Natural Computation Based On Dimensionality Reduction And Clustering, Weidong Ji, Yuqi Yue, Xu Wang, Ping Lin

Journal of System Simulation

Abstract: In multi-objective optimization problems, as the number of decision variables increases, the optimization ability decreases significantly. To solve "dimension disaster", a large-scale multi-objective natural computation method based on dimensionality reduction and clustering is proposed. The decision variables are optimized by locally linear embedding(LLE) to obtain the representation of high-dimensional variables in the low-dimensional space, then the individuals are grouped through K-means to select the appropriate guide individuals for the population to strengthen the convergence and diversity. To verify the effectiveness, the method is applied to the multi-objective particle swarm optimization algorithm and the non-dominated sorting genetic algorithm. The convergence …


Research On Multiple Filter Signal Compensation For Washout Algorithm Optimization Of Flight Simulator, Weichao Liu, Hui Wang Jan 2023

Research On Multiple Filter Signal Compensation For Washout Algorithm Optimization Of Flight Simulator, Weichao Liu, Hui Wang

Journal of System Simulation

Abstract: Aiming at the defects of signal loss and poor adaptability of the classical washout algorithm when applied to flight simulator, an optimization scheme of washing algorithm based on multiple filtering signal compensation is proposed. Analyzing the lost signal in classical washout algorithm, intercepting the lost signals to the depth filter with depth filtering strategy, basing on human perception errors and platform movement margin, after multiple filtering signal to certain proportion respectively compensation to the three channel of washout algorithm to achieve the maximum reduction of signal loss, thus reducing human perception error. The classical washing algorithm and the improved …


Scheduling Optimization Of Aluminum Extrusion Production Line Based On Timed Petri Net And Bso Algorithm, Yali Wu, Shuting He, Yanxi Yang, Lianqiang Feng, Fuqiang Wang, Yulu Chen Jan 2023

Scheduling Optimization Of Aluminum Extrusion Production Line Based On Timed Petri Net And Bso Algorithm, Yali Wu, Shuting He, Yanxi Yang, Lianqiang Feng, Fuqiang Wang, Yulu Chen

Journal of System Simulation

Abstract: For the problems of long production period and low efficiency caused by the complicated processes and large scheduling capacity of aluminum extrusion production line in industrial production, a timed Petri net (TdPN) scheduling model of aluminum extrusion production line is proposed and analyzed for reasonableness. The brain storm optimization (BSO) algorithm is introduced into the model, and an optimized scheduling algorithm for aluminum extrusion scheduling problems is proposed based on the individual encoding and decoding methods. The simulated annealing local search mechanism is used to improve the performance of BSO algorithm in the later stage, which can achieve the …


Dynamic Risk Assessment Of Vocs Cross Regional Flow Based On Petri Nets, Guangqiu Huang, He Wang Jan 2023

Dynamic Risk Assessment Of Vocs Cross Regional Flow Based On Petri Nets, Guangqiu Huang, He Wang

Journal of System Simulation

Abstract: In order to evaluate the interaction between regions due to the cross regional flow of VOCs(volatile organic compounds) under polluted weather, a dynamic risk assessment method of cross regional flow of VOCs is proposed by using Petri net modeling method. The migration paths of VOCs between multiple potential pollution sources and contaminated areas are determined by HYSPLIT model, and the relationship between each migration path is described by Petri net; the dynamic risk assessment method is defined, and the calculation of dynamic risk is integrated into the operation of functional Petri net; through case analysis, the dynamic risk assessment …


Research On System Of Virtual-Reality Fusion And Inquiry-Based Learning, Yongning Zhu, Zeru Lou, Tianxiang Wu, Jianmin Wang Jan 2023

Research On System Of Virtual-Reality Fusion And Inquiry-Based Learning, Yongning Zhu, Zeru Lou, Tianxiang Wu, Jianmin Wang

Journal of System Simulation

Abstract: With the increasing interest in personalized and self-motivated education, emphasizing active learning and practical experiences, inquiry-based learning (IBL) is attracting interest in education. Considering the requirement for inquiry-based education, a framework of full process inquiry-based learning environment in the real-virtual worlds is designed. As an example, a mixed-reality chemical experiment system is developed. The metadata including user behavior data, interactive suite status and interactive interface status is collected through physical sensing. By mapping real-world status to the virtual world avatar, virtual experiments are simulated with computational dynamic solvers and real-time rendering. The generated images are sent back to the …


Drosophila Retina Simulation System And The Emergence Of Orientation Selectivity, Ziyu Liu, Yiran Zhuo, Zhuoyi Song Jan 2023

Drosophila Retina Simulation System And The Emergence Of Orientation Selectivity, Ziyu Liu, Yiran Zhuo, Zhuoyi Song

Journal of System Simulation

Abstract: To investigate the biophysical mechanisms underlying the Drosophila retinal computations, a piece of simulation software is constructed. By constructing the connectivity of the optical structure of the Drosophila compound eye with the neural network and retinal neuronal information encoding processes,, the retinal transformation from the light to the electrical signals is simulated. The photo-transduction model is optimized by a stochastic process. The generating mechanism of orientation selectivity (OS) is explored in the Drosophila retina's output neurons through a simulation system. Experiments show that with comparable simulation accuracy, the simulation speed increases by 40 times. The software can now be …


Short-Time Human Activity Recognition Based On Wavelet Features Matching, Benyue Su, Li Zhang, Qingxuan He, Min Sheng Jan 2023

Short-Time Human Activity Recognition Based On Wavelet Features Matching, Benyue Su, Li Zhang, Qingxuan He, Min Sheng

Journal of System Simulation

Abstract: The selection of features is the key problem in the study of human activity recognition. In order to obtain sufficient and stable behavioral features, long-time behavioral data that exceed one behavior cycle are often processed, while short-time behavioral data with less than one behavioral cycle are usually unstable, making it difficult to achieve accurate and stable identification. This paper proposes a short-time human activity recognition method based on the combination of wavelet transform and template matching. Coefficient features are extracted using wavelet transform method. The features of the short-time test samples are matched with the features in the template …


Research On Vr Experience Comfort Based On Motion Perception, Wei Quan, Chao Wang, Xuena Geng, Cheng Han Jan 2023

Research On Vr Experience Comfort Based On Motion Perception, Wei Quan, Chao Wang, Xuena Geng, Cheng Han

Journal of System Simulation

Abstract: A VR video comfort evaluation model based on motion perception is proposed for viewers who will feel discomfort such as vertigo and nausea after a virtual reality (VR) experience. By performing dense optical flow estimation on stereoscopic VR video and calculating the video frame velocity matrix by analyzing the horizontal and vertical motions in the scene, the frame acceleration feature extraction methods based on frame difference method and based on time domain are proposed. Taking the extracted velocity, acceleration and other motions features as input, a model is established using the support vector regression algorithm, and VR video experience …


A Multi-Resolution Simulation Modeling Method, Zhaopeng Liu, Xinhai Xu, Bowen Yuan, Jinlu Zhang Jan 2023

A Multi-Resolution Simulation Modeling Method, Zhaopeng Liu, Xinhai Xu, Bowen Yuan, Jinlu Zhang

Journal of System Simulation

Abstract: Aiming at the resolution gap between the operation task issued by the high-level commanders and the simulation system model instructions in the human-in-the-loop simulation deduction, a multi-resolution modeling method based on behavior tree is proposed. By improving the behavior tree syntax, the low-resolution combat missions are disaggregated into high-resolution simulation system instructions. By designing a decision model embedded in the behavior tree, the problem of resource uncertainty and execution effect uncertainty faced in the execution of model instructions is solved. A combat scenario for seizing air supremacy is designed to verify the effectiveness of the method.


Research On Intelligent Prediction Method Of Wargaming Air Mission, Dayong Zhang, Jingyu Yang, Xi Wu Jan 2023

Research On Intelligent Prediction Method Of Wargaming Air Mission, Dayong Zhang, Jingyu Yang, Xi Wu

Journal of System Simulation

Abstract: The efficient, accurate and automatic judgment of the combat mission or intention of the enemy's air targets in the battlefield is the basis of situation awareness and the key to the allocation of auxiliary combat resources. Combined with the calculation characteristics of feed forward deep neural network and long-term and short-term memory network model, two targeted basic index learners are designed, and then the weighted combination is carried out according to the cross entropy of the basic index, which can be used to further train the evaluation index of the learner. It can not only effectively prevent the model …


Research On Intelligent Optimization Method Of Combat Sos Based On Gabc Algorithm, Hucheng Zhang, Jingyu Yang Jan 2023

Research On Intelligent Optimization Method Of Combat Sos Based On Gabc Algorithm, Hucheng Zhang, Jingyu Yang

Journal of System Simulation

Abstract: In order to solve the problem that exploratory simulation can not traverse the solution space quickly, and provide the auxiliary decision-making scheme in real time, a genetic algorithm based on classifier is proposed. The framework of simulation optimization method based on the algorithm is established. It can find the optimal solution according to the dynamic changes of key factors and decision targets of the system, which is suitable for such as seeking the best efficiency-cost ratio scheme and the optimization of the optimal power deployment and other systems. Based on the simulation bed system of the National Defense …


Application Of Neural Networks For Hydrologic Process Understanding At A Midwestern Watershed, Annushka Aliev, Sinan Rasiya Koya, Incheol Kim, Jongwan Eun, Elbert Traylor, Tirthankar Roy Jan 2023

Application Of Neural Networks For Hydrologic Process Understanding At A Midwestern Watershed, Annushka Aliev, Sinan Rasiya Koya, Incheol Kim, Jongwan Eun, Elbert Traylor, Tirthankar Roy

Department of Civil and Environmental Engineering: Faculty Publications

The Shell Creek Watershed (SCW) is a rural watershed in Nebraska with a history of chronic flooding. Beginning in 2005, a variety of conservation practices have been employed in the watershed. Those practices have since been credited with attenuating flood severity and improving water quality in SCW. This study investigated the impacts of 13 different controlling factors on flooding at SCW by using an artificial neural network (ANN)-based rainfall-runoff model. Additionally, flood frequency analysis and drought severity analysis were conducted. Special emphasis was placed on understanding how flood trends change in light of conservation practices to determine whether any relation …


Comparing The Performance Of Different Machine Learning Models In The Evaluation Of Solder Joint Fatigue Life Under Thermal Cycling, Jason Scott Ross Jan 2023

Comparing The Performance Of Different Machine Learning Models In The Evaluation Of Solder Joint Fatigue Life Under Thermal Cycling, Jason Scott Ross

Dissertations and Theses

Predicting the reliability of board-level solder joints is a challenging process for the designer because the fatigue life of solder is influenced by a large variety of design parameters and many nonlinear, coupled phenomena. Machine learning has shown promise as a way of predicting the fatigue life of board-level solder joints. In the present work, the performance of various machine learning models to predict the fatigue life of board-level solder joints is discussed. Experimental data from many different solder joint thermal fatigue tests are used to train the different machine learning models. A web-based database for storing, sharing, and uploading …


Coriolis Forces On Wind Turbine Wakes Within A Wind Farm, Natalie Violetta Frank Jan 2023

Coriolis Forces On Wind Turbine Wakes Within A Wind Farm, Natalie Violetta Frank

Dissertations and Theses

As wind plant footprints and turbine scales grow larger, understanding the interactions between mesoscale physical phenomena, such as Earth's rotation, and large-scale farm wakes become increasingly important. Current field research notes spatial and temporal influences on the global farm wakes caused by Coriolis forces. However, using field experiments to study this is notoriously difficult as there is additional influence from wind veer in the atmospheric boundary layer caused by many factors ranging from terrain to the diurnal cycles. Experiments are performed on a wind plant under the influence of Coriolis forces. This is achieved by placing the wind plant on …


Data Integration Based Human Activity Recognition Using Deep Learning Models, Basamma Umesh Patil, D V Ashoka, Ajay Prakash B. V Jan 2023

Data Integration Based Human Activity Recognition Using Deep Learning Models, Basamma Umesh Patil, D V Ashoka, Ajay Prakash B. V

Karbala International Journal of Modern Science

Regular monitoring of physical activities such as walking, jogging, sitting, and standing will help reduce the risk of many diseases like cardiovascular complications, obesity, and diabetes. Recently, much research showed that the effective development of Human Activity Recognition (HAR) will help in monitoring the physical activities of people and aid in human healthcare. In this concern, deep learning models with a novel automated hyperparameter generator are proposed and implemented to predict human activities such as walking, jogging, walking upstairs, walking downstairs, sitting, and standing more precisely and robustly. Conventional HAR systems are unable to manage real-time changes in the surrounding …


Effect Of Blank Moisture Content On Forming Behaviour And Mechanical Properties Of Paperboard Tray Packages, Arvo Niini, Lena Berthold, Tobias Müller, Panu Tanninen, Jens-Peter Majschak, Juha Varis, Ville Leminen Jan 2023

Effect Of Blank Moisture Content On Forming Behaviour And Mechanical Properties Of Paperboard Tray Packages, Arvo Niini, Lena Berthold, Tobias Müller, Panu Tanninen, Jens-Peter Majschak, Juha Varis, Ville Leminen

Journal of Applied Packaging Research

Tray blanks were moisturised to study the effect of different blank moisture content levels on forming behaviour and mechanical properties of paperboard tray packages. The blank moisturisation was done by spraying water to the blanks before their three-dimensional (3D) forming. The trays were 3D formed by press forming or deep drawing. Visual quality and punch force values were used as indicators to evaluate the forming behaviour of the trays. The mechanical properties of the trays were investigated with compression, torsion, and storing tests. A high blank moisture content reduced the punch force, and the elevated blank moisture was connected to …


Water Quality Engineering And Wastewater Treatment Ii, Yung-Tse Hung, Rehab Abdel Rahman, Hamidi Abdul Aziz, Issam A. Al-Khatib, Tsuyoshi Imai Jan 2023

Water Quality Engineering And Wastewater Treatment Ii, Yung-Tse Hung, Rehab Abdel Rahman, Hamidi Abdul Aziz, Issam A. Al-Khatib, Tsuyoshi Imai

Civil and Environmental Engineering Faculty Publications

In this respect, the modeling of the organic matter removal kinetics from municipal sewerage in horizontal subsurface flow CWs was carried out using a conventional first-order model and sigmoidal k-n model [[12]]. Water is an essential natural compound on earth; all life forms on our planet need water to function properly. The presented water management research in this Special Issue aimed to assess natural water quality in different areas, i.e., Brazil, Palestine, and China. [Extracted from the article]


Aircraft Communication Systems - Topologies, Protocols, And Vulnerabilities, Tyler Przybylski, Niroop Sugunaraj, Prakash Ranganathan Jan 2023

Aircraft Communication Systems - Topologies, Protocols, And Vulnerabilities, Tyler Przybylski, Niroop Sugunaraj, Prakash Ranganathan

Electrical Engineering Student Publications

Aviation systems are facing fierce competition driven by private investments promoting the development of new avionics suites (AS). With these new AS comes the need for a faster and larger bandwidth requirement for next generation communication systems. The legacy military (MIL) standard 1553 communication system (e.g., 1Mbps) can no longer keep up with the surge in bandwidth demand requirements. The new communication systems need to be designed with a system architecture background that can enable simplistic integration with Information Technology (IT) controlled groundnetworks, military, and commercial payloads. To facilitate a seamless integration with communication architecture, the current system is highly …


Anaerobic Toluene Biodegradation Potential At A Superfund Site Where Toluene Biosynthesis Was Observed, George Carson Jan 2023

Anaerobic Toluene Biodegradation Potential At A Superfund Site Where Toluene Biosynthesis Was Observed, George Carson

LSU Master's Theses

At a Superfund site near Baton Rouge, LA, the subsurface injection of molasses has been used to stimulate anerobic reductive dechlorination of halogenated organic compounds (e.g., 1,2-dichloroethane and vinyl chloride) present in the groundwater. Following some molasses injections, temporary accumulation of toluene and p-cresol was observed in the groundwater. Accumulation of these aromatic hydrocarbons, which were not detected in the molasses, has been attributed to anaerobic biotransformation of the amino acids phenylalanine and tyrosine. Experiments reported here were conducted in support of an effort to determine if toluene biodegrading bacteria were present in the area where anaerobic toluene accumulation was …


The Security And Cyber Defence Realities And Difficulties In Algeria, Kada Aicha Jan 2023

The Security And Cyber Defence Realities And Difficulties In Algeria, Kada Aicha

Journal of Police and Legal Sciences

This research paper aims to shed light on the digital challenge faced by Algeria as it enters the world of the knowledge society, which qualifies it to achieve cybersecurity and cyber defense against various forms and types of security threats, including cyber threats. The researcher used an analytical approach to understand the phenomenon under study and trace its causes, in addition to a case study method to study all aspects of the studied phenomenon and identify the characteristics of the case study - Algeria was chosen as the analysis unit. The study concluded several important results, including:

The deficiency of …


Social Networks And Their Impact On Social Values In The United Arab Emirates, Muhammad Al-Naqbi Jan 2023

Social Networks And Their Impact On Social Values In The United Arab Emirates, Muhammad Al-Naqbi

Journal of Police and Legal Sciences

The aim of the study was to measure the impact of social media networks on societal values in the United Arab Emirates (UAE). To achieve this objective, a questionnaire was used as a data collection tool, and a social survey method was employed within the study's community. A simple random sample of 50 individuals was selected from the employees of the Social Support Center and the Department of Social Care in the Emirate of Sharjah. The study found several results, including that social media networks contribute to learning unethical behaviors and the spread of extremist ideas that affect societal values. …


Acknowledgments Of Reviewers Jan 2023

Acknowledgments Of Reviewers

Journal of Sustainable Mining

No abstract provided.


Data-Driven Nonparametric Joint Chance-Constrained Programming For Power Systems Scheduling, Chutian Wu Jan 2023

Data-Driven Nonparametric Joint Chance-Constrained Programming For Power Systems Scheduling, Chutian Wu

LSU Doctoral Dissertations

This dissertation is dedicated to implementing data-driven nonparametric joint chance constraints (JCC) to power system optimization problems. Power generated by renewable sources, such as solar farms, is an uncertain parameter. Several approaches solve optimization under uncertainty, including stochastic programming, robust programming, and chance-constrained programming. Uncertain parameters may not belong to any parametric class of probability functions. Thus, methods that consider such uncertainty as a random variable that fits in a known probability density function (PDF) have limitations. This study focuses on chance-constrained programming under nonparametric or data-driven distributionally robust uncertainty settings.

Studies based on chance-constrained programming usually focus on individual …


Studying The Compressive, Tensile And Flexural Properties Of Binary And Ternary Fiber-Reinforced Uhpc Using Experimental, Numerical And Multi-Target Digital Image Correlation Methods, Behrooz Dadmand, Hamed Sadaghian, Sahand Khalilzadehtabrizi, Masoud Pourbaba, Milad Shirdel, Amir Mirmiran Jan 2023

Studying The Compressive, Tensile And Flexural Properties Of Binary And Ternary Fiber-Reinforced Uhpc Using Experimental, Numerical And Multi-Target Digital Image Correlation Methods, Behrooz Dadmand, Hamed Sadaghian, Sahand Khalilzadehtabrizi, Masoud Pourbaba, Milad Shirdel, Amir Mirmiran

Civil Engineering Faculty Publications and Presentations

Compressive, tensile, and flexural properties of ultra-high-performance concrete (UHPFRC) specimens were studied in this research. Binary and ternary combinations of micro steel (MS), round crimped (RC), crimped (C), hooked-end (H), and polypropylene (PP) fibers were used in overall ratios of 2% by volume of concrete. For this purpose, 100 x 200 mm cylindrical specimens, dog-bone specimens (length: 330 mm, width: 80 mm, thickness: 40 mm), and prismatic beams with a dimension of 100 x 100 x 500 mm (clear span: 450 mm) were cast and tested under compressive, tensile, and four-point bending tests (4PBT). A digital image correlation (DIC)-based method …


Real Depth-Correction In Ground Penetrating Radar Data Analysis For Bridge Deck Evaluation, Sepehr Pashoutani, Jinying Zhu Jan 2023

Real Depth-Correction In Ground Penetrating Radar Data Analysis For Bridge Deck Evaluation, Sepehr Pashoutani, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

When ground penetrating radar (GPR) is used for the non-destructive evaluation of concrete bridge decks, the rebar reflection amplitudes should be corrected for rebar depths to account for the geometric spreading and material attenuation of the electromagnetic wave in concrete. Most current depth-correction methods assume a constant EM wave velocity in the entire bridge deck and correct GPR amplitudes based on the two-way travel time (TWTT) instead of the actual rebar depth. In this paper, we proposed a depth-correction algorithm based on the real rebar depths. To compare different depth-correction methods, we used gprMax software to simulate GPR signals in …


Numerical Study Of Owls’ Leading-Edge Serrations, Asif Shahriar Nafi Jan 2023

Numerical Study Of Owls’ Leading-Edge Serrations, Asif Shahriar Nafi

Electronic Theses and Dissertations

The silent flight ability of owls is often attributed to their unique wing morphology and its interaction with their wingbeat kinematics. Among these distinctive morphological features, leading-edge serrations stand out – these are rigid, miniature, hook-like patterns located at the leading edge of the primary feathers of their wings. It had been hypothesized that these leading-edge serrations serve as a passive flow control mechanism, influencing the aerodynamic performance and potentially affecting the boundary layer development over the wing, subsequently influencing wake flow dynamics. Despite being the subject of research spanning multiple decades, a consensus regarding the aerodynamic mechanisms underpinning owls’ …


Network Structures And The Properties Of Na-Ca-Sr-Borophosphate Glasses, Parker T. Freudenberger, Rebekah L. Blatt, Randall E. Youngman, Richard K. Brow Jan 2023

Network Structures And The Properties Of Na-Ca-Sr-Borophosphate Glasses, Parker T. Freudenberger, Rebekah L. Blatt, Randall E. Youngman, Richard K. Brow

Materials Science and Engineering Faculty Research & Creative Works

Borophosphate glasses were prepared with the nominal molar compositions 16Na2O-(24-y)CaO-ySrO-xB2O3-(60-x)P2O5 (mol%), where 0≤x≤60 and y=0, 12, and 24. Information about the compositional dependence of borate and phosphate site speciation and next nearest neighbor linkages was obtained by 11B and 31P MAS NMR and Raman spectroscopies, and by high pressure liquid chromatography (HPLC). With the initial replacement of P2O5 by B2O3, tetrahedral borate sites linked to four phosphate anions, B(ØP)4, are created in the glass structure, and the average phosphate anion becomes smaller as bridging PØP bonds are replaced by bridging PØB bonds. With further increases in the B2O3 content, borate …