Physical Sciences and Mathematics Commons^™

A Method For Calculating Lateral Surface Area Of Bistatic Radar Beam Overlap, James I. Murray, Fredrick A. Jenet

Physics & Astronomy Faculty Publications

It has been shown that bistatic radars using radio telescopes as receivers can be used to increase the sensitivity of orbital debris measurements over traditional terrestrial monostatic radar. A method to calculate the lateral surface area of a bistatic radar is needed to evaluate the efficacy of a proposed bistatic radar configuration for orbital debris measurements. For over three decades, models of the orbital debris (OD) environment in low Earth orbit (LEO) have been developed to assess the risk posed by OD to spacecraft. While terrestrial radar measures debris 3 mm and larger and in situ measurements provide data for …

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

Assessing Ecological Relationships Among Late Triassic Vertebrates In Petrified Forest National Park, Alexandra Davis Apgar

Earth and Planetary Sciences ETDs

The complex vertebrate ecosystem of the Late Triassic has not yet been fully understood, largely due to oversimplification of hypothesized trophic hierarchies and limited preservation of direct evidence of faunal interaction. Paleocommunity reconstruction attempts can also fall victim to taphonomic biases, time-averaging inaccuracies, and non-analogue paleoecologies. Utilizing a combination of PAIRS analysis and NMDS ordination, we highlight vertebrate faunal relationships within the Adamanian and Revueltian faunachrons of Petrified Forest National Park, assess the likelihood that these patterns have ecological rather than preservational drivers, and examine how these potential interactions may have been impacted by the Adamanian-Revueltian turnover event. We are …

An Interactional Account Of Empathy In Human-Machine Communication, Shauna Concannon, Ian Roberts, Marcus Tomalin

Human-Machine Communication

Efforts to develop empathetic agents, or systems capable of responding appropriately to emotional content, have increased as the deployment of such systems in socially complex scenarios becomes more commonplace. In the context of human-machine communication (HMC), the ability to create the perception of empathy is achieved in large part through linguistic behavior. However, studies of how language is used to display and respond to emotion in ways deemed empathetic are limited. This article aims to address this gap, demonstrating how an interactional linguistics informed methodological approach can be applied to the study of empathy in HMC. We present an analysis …

Geophysical Imprint Of Mining-Induced Rock Mass Deformation In The Area Of Construction Disaster In Bytom (Poland), Andrzej Kotyrba, Łukasz Kortas

Journal of Sustainable Mining

The paper presents the analysis of the results of geophysical surveys conducted in the mining area located in Bytom – Karb (USCB, Poland) in the aspect of identifying the causes of significant damage to the complex of inhabited tenement houses which occurred in 2011. The surveys were carried out by microgravimetric and GPR methods. The construction disaster was caused by the exploitation of one of the hard coal seams at a depth of about 800 m along the mining longwall running underneath the settlement. The terrain deformation parameters exceeded the forecasted values, and in several places discontinuities took linear forms …

Concurrent Reduction And Stabilization Of Graphene Oxide Dispersion By Silk-Inspired Polymer, Zoren Valmonte, Zeyad Baker, Jianna Loor, Amrita Sarkar

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Silk, a popular biomaterial, is used as a greener alternative of toxic reducing agent in biocompatible graphene synthesis. However, silk often forms gel uncontrollably due to its heavy-chain molecular weight and faces significant challenges in the reduction, stabilization, and dispersion process of graphene. In this contribution, we report a rapid chemical synthesis approach for a low-molecular-weight silk-inspired polymer via ring-opening and microwave-assisted Diels-Alder-aided step-growth polymerizations. This synthetic polymer with periodic sequences of hydrophilic and hydrophobic moieties not only reduces graphene oxide efficiently but also enhances the dispersibility of hydrophobic reduced graphene oxide in aqueous media.

Photophysical Properties Of Synthetic Oligomeric Phenylene Ethynylene, Hugh F. Fritz Jr.

Chemistry and Chemical Biology ETDs

Oligomeric Phenylene Ethynylenes (OPEs) are a class of synthetically prepared compounds with the basic structure of phenylene rings connected by triple-bonded carbon atoms, also known as an ethyne link. This structure can be modified by incorporating functional groups onto one or more of the phenylene rings. The addition of functional groups, such as sulfoxide or imidazole, may alter the photophysical properties in detectable ways. The photophysical techniques used in this report include fluorescence, spectroscopy in the ultraviolet and visible light range (UVVIS), and photon-based excitation using a photo chamber.

One attractive function of OPEs is their antimicrobial property. Previously published …

Draft Final Revised Residential Metals Abatement Program (Rmap) Quality Assurance Project Plan (Qapp) (Residential Parcels), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Research Progress On Properties Of Fiber Modified Asphalt Mixture, Liang Bo, Zhang Haitao, Liu Zheng, Liao Wei

Journal of China & Foreign Highway

As a kind of asphalt mixture additive and stabilizer, fiber can effectively improve the performance index of asphalt pavement and extend the service life of asphalt pavement. Based on the analysis of relevant literature in China and abroad, this paper summarized the action mechanism of fiber modified asphalt and asphalt mixture, the effect of fiber content on properties, and the characteristics of different types of fiber modified asphalt. Fiber can effectively improve the high temperature property, low temperature property, and fatigue property of asphalt mixture, especially the resistance to low temperature and fatigue cracking of asphalt mixture. The modification effect …

Review Of Research Progress Of Frame Beam Anchore D Structure In Slope Supporting, Zhang Junhui, Zhou Qinwei, Li Feng, Zhang Shiping

Journal of China & Foreign Highway

This paper summarized the research status of frame beam anchored structures in slope supporting and reinforcement engineering in China and abroad. It analyzed the results of structural design, model test, and field construction. Through induction and analysis, it is found that the current design of frame beam anchored structure has certain limitations, and it is necessary to form a universal design theory and method. The model test of frame beam anchored structure in slope supporting is limited by the test equipment and conditions and fails to be carried out on a large scale. The key points and standards of the …

Numerical Analysis Of Structural Characteristics Of Prefabricated Ecological Grid Retaining Walls, Wang Xinquan, Zhu Cong, Huang Tianyuan, Diao Hongguo, Peng Xijian

Journal of China & Foreign Highway

The retaining wall is a common slope protection structure. In view of the current insufficient greening and high prefabricated retaining walls, prefabricated ecological grid retaining walls with high construction efficiency and greening features emerge. In order to explore the mechanical characteristics and influencing factors of prefabricated ecological grid retaining walls, Abaqus finite element software was used to discuss the mechanical characteristics of prefabricated ecological grid retaining wall columns and inclined shelves with different embankment heights and different fillings. The results show that different fill heights have different effects on the lateral displacement of the column, and the effect of fill …

Study On Effectiveness Evaluation Method Of Expressway Drainage System In Rainy Area, Luo Datian, Li Jiayi, Zou Jingrong

Journal of China & Foreign Highway

In order to comprehensively evaluate the effectiveness of expressway drainage systems in rainy areas and comprehensively analyze the factors affecting the effectiveness of drainage systems, this paper took the perfection of drainage system, stability of drainage facilities, and road traffic safety as the first-level evaluation index and six kinds of influencing factors such as the degree of integrity as the second-level index, and it put forward the evaluation criteria of the effectiveness of expressway drainage system in rainy areas. The fuzzy comprehensive evaluation method was used to determine the membership degree of expert scoring through the trapezoid membership function, and …

Macro And Micro Analysis Of Influence Mechanism Of Anti⁃Slide Pile Position On Slope Stability, Liu Ping, Wang Meijing, Zhang Shaoqiang, Zhang Yongsheng, Wang Denghua, Li Dongdong

Journal of China & Foreign Highway

In order to study the influence mechanism of anti-slide pile position on the stability of the slope and optimize the supporting parameters of anti-slide piles reasonably, a three-dimensional continuous and discrete coupled numerical model of the slope was established based on the finite difference theory and discrete element theory of a highway cut slope in southwest China. The influence mechanism of anti-slide pile position on the stability of the cut slope was analyzed from macro and micro perspectives. The results show that the force chain of particles on the sliding surface is thin at the top and dense at the …

Experimental Study On Interface Fatigue C Haracteristics Of Asphalt P Avement Pothole Patch Under External Factors, Ai Changfa, Shao Zhutao, Huang Yangquan, Ren Dongya

Journal of China & Foreign Highway

After the asphalt pavement patch for potholes is put into use, the interface joints around it are prone to fatigue and durability problems under the action of external factors such as the natural environment and driving load effect. In order to analyze the fatigue characteristics of the repaired interface joints under the action of external factors, the four-point bending fatigue test and pull-out test, combined with the results of orthogonal analysis, were used to determine the best bonding scheme of the repaired interface. The influence of external factors such as temperature, frequency, and strain level on the fatigue life of …

Study On Improvement Of Early Skid Resistance Of Sma Asphalt Pavement Based On Spreading Grit, Jiang Zhaowei, Wei Jincheng, Liu Hang, Sun Qiang, Li Xia

Journal of China & Foreign Highway

The early skid resistance of SMA 13 pavement is poor. To address this issue, the existing research results were analyzed, and physical detection was conducted. It was found that the large structure pavement failed to provide good early skid resistance detection value. Based on the principle of spreading abrasive materials, two methods to improve the early skid resistance of SMA pavement were proposed. The particle size of abrasive material was determined to be 2.36–4.75 mm, and the spreading amount was 0.82 kg/m2, which verified the safety of the methods. The test results show that the two methods can slightly improve …

Crack Resistance Of Basalt Fiber Asphalt Pavement Under The Coupling Effect Of Low Temperature⁃Load In Heavy Freezing Area, Guo Yinchuan, Hao Chenwei, Guo Han, Fan Li, Shen Aiqin, Wang Lusheng

Journal of China & Foreign Highway

In view of the cold working environment and road diseases of asphalt pavement in the heavy freezing area of Inner Mongolia, a control index of pavement structure based on crack resistance was proposed. The calculation models of the newly built basalt fiber asphalt pavement structure and the pavement after cracks were established by using Ansys finite element software. The mechanical parameters, thermophysical parameters, and other parameters of the basalt fiber asphalt pavement were determined through laboratory tests, and the crack resistance indexes under the coupling action of low temperature and load were calculated, respectively. The fatigue life of basalt fiber …

Detailed Structure Of Double ⁃Layer Porous Asphalt Pavement Under Three Paving Technologies, Zhang Zhenshan, Liao Gongyun, Wang Can, Zhang Yi, Cai Yang, Fang Xin, Wu Wei

Journal of China & Foreign Highway

For three kinds of construction technologies of double-layer drainage pavement (traditional “hot + cold” paving technology, “hot + warm” paving technology, and “hot + hot” integrated molding technology), the discrete element method and laboratory test were used to make plate specimens and cylindrical specimens, respectively, and the interlayer morphology of double-layer drainage pavement under the three kinds of construction technologies was compared. Based on the virtual shear test and laboratory direct shear test, the effects of construction technologies and amount of adhesive oil on the interlayer shear strength of double-layer drainage pavement were analyzed. By means of visualization, the distribution …

Design And Stress Analysis Of Baqiutian Jointless Arch Br Idge In Yunnan, Chen Baochun, Sun Tongqing, Huang Qingwei, Han Yu, Shi Zhi

Journal of China & Foreign Highway

The bridge without expansion joints, with the expansion device removed, can completely solve the maintenance problem of the expansion device and is sustainable. Its application is mainly in beam bridges and relatively few in arch bridges. In this paper, the Baqiutian Bridge in Yunnan Province was taken as an example, which is an upper bearing arch bridge. The arch path structure is directly connected with the two approach spans to form a continuous structure and extends to the guide plate (approach slab) behind the platform, thus eliminating the expansion joints of the whole bridge floor and making it an arch …

Optimization Design Of Uhpc ⁃Nc Continuous Box Girder Bridge Based On Response Surface Method, Guan Weiyi, Duan Luqi

Journal of China & Foreign Highway

In order to solve the two major problems of mid-span deflection and cracking in the late stage of the long-span bridge, a UHPC-NC hybrid beam design scheme was proposed, and some design parameters were optimized based on the response surface method. By optimizing the local parameters, namely the thickness of the roof, web, and bottom plates of the mid-span section, and the overall parameters, such as the UHPC replacement ratio, the number of beam curves, and the height of the mid-span beam, the optimal parameter combination was obtained as follows: roof thickness of 22 cm, web plate thickness of 25 …

Analysis And Optimal Adjustment Of Manufacturing Errors Of Main Girder Of Long ⁃Span Steel Box Cable ⁃Stayed Bridge, Tu Guangya, Zhou Zhizhe

Journal of China & Foreign Highway

In order to study the influence of the random manufacturing error of the main girder permitted by the research specification on the alignment of the finished long-span steel box cable-stayed bridge, guided by the adaptive stress-free configuration construction control theory, the Shishou Yangtze River Highway Bridge, a long-span twin-tower cable-stayed bridge, was studied. The influence and propagation characteristics of the random error effect of the main girder members on the main structure of the cable-stayed bridge were analyzed. The adverse effects of random manufacturing errors of the main girder on the structure of the cable-stayed bridge were studied. The results …

Research On Budget Quota Of Highway Bridge Crack Treatment, Chang Ding, Yu Licun

Journal of China & Foreign Highway

In view of the lack of a unified budget quota for concrete structure crack treatment, a large number of measured data and fuzzy analytic hierarchy process were used to calculate the consumption of budget quota through the amplitude difference coefficient of construction quota. According to the technical specifications of highway bridge reinforcement engineering, reasonable crack treatment methods and engineering contents were determined, and the quota of structure crack treatment was prepared by using the physical quantity. The quota cost was compared with actual engineering cases. The results show that the quota cost and the actual project cost are basically at …

Case Study Of Steel Wire Corrosion In Hoist Cable Of Half ⁃Through Arch Bridge, Xu Hongsheng, Jiang Lei, Yan Donghuang

Journal of China & Foreign Highway

In order to understand the causes and development rules of steel wire corrosion diseases inside the hoist cable of half⁃through and through arch bridges, this paper systematically studied the defects and loopholes of the protection system for the hoist cable of two half⁃through steel arch bridges by disintegrating the old hoist cables of Yuehai Bridge in Yinchuan and Xiangjiang Bridge in Heishipu Street in Changsha City. It probed into the distribution rules of corrosion diseases of steel wire inside the hoist cables. The main reasons leading to the difference in steel wire corrosion disease inside the old hoist cables of …

Design Of Super Large Cantilever Wing ⁃Box Girder Bridge, Zhong Hao

Journal of China & Foreign Highway

In recent years, with the rapid development of urban bridge construction, the bridge inevitably needs to cross the existing railway and road in the construction project. This kind of bridge has the characteristics of a large span and limited pier space. At the same time, in order to meet the increasing traffic demand, the transverse width of the bridge is increasing, so the application of large cantilever wing-box girder structures is becoming more and more extensive. Based on the overspan railway bridge project of the northern section of the Wuhan Fourth Ring Line (Wuhu–Wujiashan), this paper introduced the design difficulties …

Study On Reasonable Seismic System Of Long ⁃Span Concrete Beam Bridge In Strong Earthquake Areas, Yu Deen, Han Shanjian, Sun Pingkuan

Journal of China & Foreign Highway

In this paper, a three-dimensional finite element dynamic model of the Longtang Nandujiang Bridge in Hainan Province was established. Firstly, the selection of ground motion input and the establishment of the finite element model were introduced. Secondly, the influence of different design parameters (support radius) of the friction pendulum bearing on the seismic response of the bridge was discussed, and the optimal bearing parameters suitable for the bridge were obtained. Finally, the seismic responses of the bridge under three different constraint structures, namely conventional constraint system, seismic isolation system of friction pendulum bearing, and rigid frame bridge system, were compared. …

Calculation Of Arch Rib Installation Alignment Of Large Span Cable Hoisting Arch Bridge, Xiong Shaohui, Guo Xin, You Zuoqiao

Journal of China & Foreign Highway

Cable hoisting method is the most important construction method for long-span arch bridges. In the process of arch rib lifting, the partial consolidation of the joint caused by temporary bolt connection, the deflection of the tower caused by the temporary construction load of the main cable, and the free expansion of the anchor cable and the buckle cable caused by temperature change will have a great influence on the installation alignment of the arch rib. In this paper, a two-element model method considering stiffness loss was used to calculate the correction value of the arch rib installation alignment more accurately …

Thickness Detection Of Reinforced Concrete Protective Layer Based On Environ Mental Calibration, Hong Hua, Xu Jianhong, Cao Sugong, Fu Junlei

Journal of China & Foreign Highway

In order to solve the problem of inaccurate detection of reinforced concrete protective layer thickness in engineering, this paper studied and formed a reasonable and perfect method and calibration procedure for the detection of reinforced concrete protective layer thickness in highway and water transportation engineering by using the analysis of influencing factors. The results show that the accuracy of measuring the protective layer thickness of reinforced concrete in practical engineering can be effectively improved. The production of standard instrument calibration specimens can be saved, and the testing process can be standardized.

Correlation Analysis Between External Damages And Transverse Load Distribution Capacit Y Of Hollow Slab Bridges, Cao Hao, Sun Dunhua, Wang Zichen, Zhao Fuli, Sun Haipeng, Xiong Wen

Journal of China & Foreign Highway

To correctly evaluate the service status of prefabricated hollow slab girder bridge, based on the measured data of apparent disease and load test of hollow slab girder bridge in reconstruction and expansion project, this paper first analyzed the data characteristics of the beam body, hinge joints, and support disease samples and obtained their statistical distribution rules. Then, according to the typical diseases (transverse cracks and hinge cracks at the bottom of the beam), the BP neural network was used to build a correlation model for them, and the close correlation between the two typical diseases of hollow slab girder bridge …

Research Of Disease Analysis And Reinforcement Technology For Typical Orthotropic Bridge Deck, Guo Fukuan, Zhou Shangmeng

Journal of China & Foreign Highway

In order to effectively solve the disease problem of orthotropic steel bridge decks, this paper relied on a steel box girder cable-stayed bridge deck reinforcement project to carry out steel bridge deck disease analysis and reinforcement technology research. The results show that the main disease of steel bridge decks is fatigue cracking. The fatigue cracks are numerous, short, and deep, and they continuously grow and cause more severe disease. The excessive fatigue stress amplitude is the main factor leading to the fatigue cracking of steel bridge decks. Once the crack occurs, the stress amplitude of the crack tip increases continuously, …

Analysis Of Installation Method And Error Control Of Steel Girder Of Steel ⁃Concrete Composite Girder Cable ⁃Stayed Bridge, Xiong Xianyong, Fu Yajun, Huang Gen

Journal of China & Foreign Highway

Compared with cable-stayed bridges with pure steel girders, the installation of a steel main girder of the steel⁃concrete composite girder cable⁃stayed bridge is more complicated, and the installation error control is more difficult. In this paper, the composite girder with a double box section was taken as the research object, and a finite element model was established to compare the installation methods of steel main girders. The best installation method was selected according to the principle of safety loading, and the causes of the installation errors of steel main girders were analyzed. The corresponding error control methods were proposed.

Cable⁃Stayed Bridge Of Cable Auxiliary Beam Arch Pylon ⁃Key Technologies Design Of Meishan Minjiang Bridge, Ma Zhendong, Lai Yaping, Chen Jiayong

Journal of China & Foreign Highway

The newly built Minjiang Bridge in Meishan City, Sichuan Province applies the concept of cable-assisted girder bridge. P4 steel arch tower combined with three-stage balanced double-plane cable and P3 and P5 auxiliary towers combined with thin cable of single cable plane were used to assist the load on the beam body, making the 2.5 m-high concrete main beam meet the requirements of the main span of 2 × 120 m. Through the analysis of the bearing force, the angle between the double-limb arch tower was 43.6°, and two pairs of cables were set in the auxiliary tower to achieve the …