Engineering Commons^™

Safety And Optimality Monitors For Learning-Enabled Systems Using Conformal Prediction, Jackson Cox

McKelvey School of Engineering Graduate Student Theses & Dissertations

The use of machine learning to create data-driven plant models and controllers has led to an increased need for safety and optimality monitors for model-based systems. System plant models are subject to uncertainty due to learning constraints such as unseen data and overfitting or physical constraints such as unknown dynamics and noise. This uncertainty is detrimental to safety-critical systems and must be properly regulated. To curb this uncertainty, we create prediction sets using the guarantees provided by Conformal Prediction. With a user-specified high probability, these prediction sets contain the true plant system states for an entire prediction horizon, which we …

Pyrophosphate-Free Glycolysis In Clostridium Thermocellum Increases Both Thermodynamic Driving Force And Ethanol Titers, Bishal Dev Sharma, Shuen Hon, Eashant Thusoo, David M. Stevenson, Daniel Amador-Noguez, Adam M. Guss, Lee R. Lynd, Daniel G. Olson

Dartmouth Scholarship

Background

Clostridium thermocellum is a promising candidate for production of cellulosic biofuels, however, its final product titer is too low for commercial application, and this may be due to thermodynamic limitations in glycolysis. Previous studies in this organism have revealed a metabolic bottleneck at the phosphofructokinase (PFK) reaction in glycolysis. In the wild-type organism, this reaction uses pyrophosphate (PPi) as an energy cofactor, which is thermodynamically less favorable compared to reactions that use ATP as a cofactor. Previously we showed that replacing the PPi-linked PFK reaction with an ATP-linked reaction increased the thermodynamic driving force of glycolysis, but only had …

Beyond The Surface: Understanding Temperature Polarisation In Dcmd Membranes Through Varied Operational Parameters, Hiras Ahamed Hijaz, Masoumeh Zargar, Abdellah Shafieian, Amir Razmjou, Mehdi Khiadani

Research outputs 2022 to 2026

Conventionally, a single Temperature Polarisation Coefficient (TPC) value is calculated to quantify Temperature Polarisation (TP). In this research, the extent of polarisation is investigated by capturing temperature profiles at specific points along a MD membrane using miniature thermocouples, eliminating the need for TPC calculations. The extent of polarisation at a point is affected by two contributory factors, namely the proximity of flow inlets and the difference in vapour pressure across the membrane at that point. Under this direction, this work examined the influence of permeate temperature, feed salinity, and flow direction on the development of the temperature profiles. Our analysis …

Kinetics Model Of Cananga (Cananga Odorata) Fresh Flower Extraction Using Microwave Hydrodistillation Method, Darnengsih Darnengsih, Hikmatun Ni’Mah, Mahfud Mahfud, Ayu Chandra Kartika Fitri

Makara Journal of Science

Recent studies have focused on improving essential oil extraction methods by incorporating advanced technologies, such as microwave-assisted hydrodistillation (MHD). Despite these advancements, further research is necessary to fully understand how different kinetic models influence extraction efficiency. This study evaluates several kinetic models for extracting essential oil from fresh Cananga flowers using MHD, examining how varying microwave power affects extraction rates and correlates with kinetic model parameters. The extraction process involved introducing 200 grams of fresh Cananga flowers in 400 mL of distilled water and subjecting the mixture to microwave power levels of 200 W, 400 W, and 600 W. The …

Optimization Of Construction Scheme Of Ultra‑Large Special‑Shaped Foundation Pit Adjacent To Existing Station And Temporary Steel Bridge, Chen Dengwei

Journal of China & Foreign Highway

With the intensifying development density of urban underground space in China，the impact of ultra-large foundation pit construction on the normal operation of adjacent structures cannot be ignored.Relying on the Huangmugang Comprehensive Transportation Hub Project in Shenzhen，this paper studied the deformation of the envelope structure and soil caused by the excavation of the ultra-large special-shaped foundation pit，as well as the structural response of the deformation of the adjacent existing station and the temporary steel bridge.The paper optimized the construction scheme of the special-shaped foundation pit excavation.The results show that the deformation trend of the envelope structure on the north and south …

Friction‑ 1d Transformer ： A 1d Vision Transformer Hybrid Model For Skid Resistance Prediction On Asphalt Pavements, Pei Feifei, Nie Zilong, Xu G Uomin, Zhan You, Gong Xianqi, Ai Changfa, Deng Yuan, Ji Zhengyun, Wang Shifa

Journal of China & Foreign Highway

The friction performance of road surfaces is an important indicator of highway safety，which is closely related to road texture.In this paper，a set of three-dimensional denoising methods for road texture data with different noise levels was proposed，which could effectively remove noise while preserving local texture features.In addition，a skid resistance prediction model named Friction- 1D Transformer was developed based on the design concept of Vision Transformer （VIT） for skid resistance evaluation of asphalt pavements.Unlike traditional convolutional neural networks，the Friction- 1D Transformer utilized positional encoding structures and multi-head attention mechanisms to extract global features from one-dimensional （1D） texture signals along the direction of …

Phosphorus Adsorption Capacity Of Volcanic Scoria, Easton Jeffrey Perkins

Theses and Dissertations

Phosphorus (P) pollution in stormwater runoff poses a significant threat to water quality, contributing to eutrophication and ecosystem degradation. This research evaluates the potential of volcanic scoria (VSco), an abundant and cost-effective resource in Utah, USA, to influence P concentrations in urban stormwater systems. Batch adsorption experiments examined the behavior of VSco across three particle sizes—fine (<0.841 mm), medium (0.841–2 mm), and granular (2.38–9.5 mm)—under conditions mimicking stormwater scenarios. The results reveal that fine VSco exhibited higher adsorption efficiency than medium and granular sizes, achieving notable P removal at higher concentrations. However, at lower concentrations, fine VSco showed potential for P release due to desorption of pre-existing P. Medium and granular VSco showed minimal adsorption capacity and, in some cases, acted as P sources, highlighting a dual potential depending on stormwater conditions. Adsorption isotherms indicate that the adsorption behavior of fine VSco aligns with the Langmuir model, with a finite and relatively low adsorption capacity. Calculated distribution coefficient (Kd) values for fine VSco ranged from 0.04 to 0.005 L/g, indicating weak adsorption efficiency compared to materials like activated carbon (1–10 L/g) or soils with moderate adsorption capacity (0.1–0.5 L/g). Loss-on-ignition tests confirmed that VSco’s performance is driven by its physical and chemical properties, particularly its calcium content, rather than organic matter. The study emphasizes caution in applying fine VSco for stormwater remediation due to its potential to release P under typical runoff conditions. However, fine VSco may still be viable in specific scenarios where P levels are higher, such as in stormwater hotspots or localized areas with elevated concentrations, allowing for targeted remediation. The research underscores the need for further testing to refine VSco’s applications, particularly in low-impact development (LID) practices, such as infiltration basins and rain gardens, to effectively manage P levels while supporting ecological and aesthetic goals. These findings contribute to understanding the complex role of VSco in urban stormwater systems, offering insights for sustainable water quality management and nutrient cycling in urban landscapes.

Developing A New Liquefaction Ejecta Prediction Model Considering Soil Properties Of Non-Liquifiable Surface Layers Using New Large Database From The 2012 Emilia Romagna, Italy Earthquakes, Jonah Bradley Dundas

Theses and Dissertations

The presence of a non-liquefied crust overlying a liquefied layer has been found to have a significant effect on sand ejecta and surficial liquefaction damage, as observed by Ishihara (1985). Following the 2010-2011 Canterbury seismic sequence in New Zealand, almost no foundation deformation occurred in areas with liquefaction susceptible soils overlain by at least a 3 meter thick crust [1]. In contrast, the 2012 Emilia-Romagna earthquake in Italy provided surface evidence of liquefaction despite 6+ meter thick crusts. Several researchers have proposed liquefaction prediction models [e.g. LPI [2], Ishihara Curves [3], LSN [4], LPIISH [5] and the methods proposed by …

Experimental Investigation On Shrinkage Effect Of Ultra‑High Performance Concrete Under Steam Curing, Li Bing, Yang Tengyu, Fang Changle, Luo Zirun, Li Chuanxi, Tan Ke

Journal of China & Foreign Highway

Determining the free shrinkage of U HPC is an important basis for analyzing the shrinkage effect of steel UHPC composite bridge deck.Therefore，based on the UHPC materials to be used in a project，three batches of UHPC free shrinkage specimens were made，and three specimens were made in each batch.By testing the strain and temperature of specimens during curing，the free shrinkage strain-age curve and temperature-age curve of UHPC were obtained.The development and variation law of UHPC shrinkage strain are discussed.Based on the experimental results，the equivalent time is introduced on the basis of Arrhenius empirical formula，and a modified model of free shrinkage is proposed.Finally，based …

Mechanical And Vegetative Performance Of Bamboo Fiber‑Reinforced Eco‑Concrete With Recycled Aggregate, Li Tao, Deng Bofan, He Maolin, Liu Ting, Chen Houde

Journal of China & Foreign Highway

In response to the current common urban construction waste disposal issue，this study utilized processed recycled construction waste aggregate and bamboo waste materials to produce bamboo fiber-reinforced eco-concrete with recycled aggregate.By adjusting the dosage of bamboo fiber，the effects of the dosage of bamboo fiber on the mechanical and vegetative performance of the concrete were systematically analyzed by means of orthogonal tests and verification methods.The test results indicate that bamboo fiber enhances the toughness of eco-concrete significantly.Particularly，when the dosage of bamboo fiber exceeds 3.0 kg/m3，there is a significant enhancement in the tensile performance of the eco-concrete with recycled aggregate.Due to the spatial …

Curing Law And Road Performance Of Polyurethane Mixture, Sun Shengkai, Zheng Mao, Tang Xiong, Liu Li, Zhong Shengran, Si Te

Journal of China & Foreign Highway

Polyurethane mixture is composed of polyurethane binder，rubber particles，and stones.Compared with ordinary asphalt mixture，it has the characteristics of a higher content of rubber particles and large void ratios.This article first tested the viscosity-time curve and viscosity-temperature curve of one-component polyurethane and determined the compaction temperature of the polyurethane mixture.Based on the rutting test，three-point bending test，water immersion Marshall test，freeze-thaw splitting test，and pendulum friction test，the road performance of the polyurethane mixture under different replacement amounts of rubber particles was tested.The research results show that the mixing temperature of PU- 1 polyurethane mixture can be basically controlled between 73 ℃ and 81 ℃，and it …

Elimination Method Of Temperature Lag Effect In Deformation Monitoring Data Of Cable‑Stayed Bridge Structures, Liu Hongshuang, Zhai Wenqiang, Zeng Guoliang

Journal of China & Foreign Highway

There is a temperature lag effect in the deformation monitoring data of the bridge structure.Eliminating the temperature lag effect is of great significance in the health monitoring of the bridge structure.Based on the linear correlation between the deformation of the bridge structure and the temperature，this paper applied the goodness of fit test and proposed a time-domain translation elimination method.On this basis，by taking the long-term synchronous monitoring of the tower inclination，beam end displacement，main girder deflection，and temperature data of a cable-stayed bridge as an example，this method was used to eliminate the temperature lag effect in the deformation monitoring data and compared with …

Sensitivity Analysis Of Parameters Of Cable‑Stayed Bridges With Full Floating Spatial Frame, Liu Anqing, Yan Tengfei, Zheng Pengju, Gu Yanlin, Li Jie, Wang Qiang

Journal of China & Foreign Highway

In order to clarify the influence of design parameters on the mechanical behavior of a cable-stayed bridge of a floating system，a finite element model of the bridge was established by using the finite element analysis software MIDAS/Civil based on a single-tower double-cable plane steel-concrete composite beam cable-stayed bridge with full floating spatial frame.The sensitivity of parameters such as temperature effect，secondary dead load，and support system in the completed bridge state was analyzed and compared with the semi-floating system of the bridge.The results show that temperature and secondary dead load have a significant impact on the deflection and stress of the main …

Segment Connection Mod E For Stiffening Girder Hoisting Construction Of Long‑Span Steel Truss Girder Suspension Bridge, Shao Guangmiao, Pan Q Uan, Yan Donghuang, Xu Hongsheng

Journal of China & Foreign Highway

In the process of stiffening girder construct ion of a long-span steel truss girder suspension bridge，different connection modes of stiffening girder segments will directly affect the internal force，alignment，and bridge state of the structure during construction.By taking the construction of the stiffening girder of a bridge as the research background，the finite element model of the whole process of the bridge was established.The advantages and disadvantages of the segmented hinge method and the segmented rigid connection method were compared，and the two-two segmented rigid connection scheme was proposed.On this basis，according to the changing law of steel truss section alignment and lower chord opening …

Linkage Control Method For Expressway Toll Stations And Plane Intersections, Lei Qing, Wang Zhaoyong, Wu Yurong, Jiang Weiwei, Luo Zhongbin

Journal of China & Foreign Highway

In order to solve the problem of vehicle queuing overflow caused by the mismatch between the expressway toll stations and the capacity of plane intersections，the formula for calculating the maximum queue length was given by analyzing the traffic operation characteristics between toll stations and plane intersections and considering vehicles ’ lane-changing behavior.Due to the strong coupling of the traffic operation between toll stations and plane intersections caused by a short distance between them，a unified linkage control optimization model was established.The research shows that if the queue length in the connecting direction of the plane intersections exceeds the allowable maximum queue …

Research On T‑Beam System With Diaphragm Based On Intelligent Construction, Liu Lang, Tao Qiyu, Xu Qigang

Journal of China & Foreign Highway

The traditional precast T-beam faces issues such as excessive diaphragms，difficult formwork installation and removal，and low levels of intelligence in intelligent bridge construction.To address these issues，this paper focused on the optimization of the number of diaphragms and the application of prefabricated diaphragms.By analyzing different diaphragm configuration schemes and comparing the contributions of prefabricated diaphragms and precast diaphragms to the lateral stiffness of the bridge，this paper deeply explored the impact of diaphragms on bridge performance.The research results indicate that the T-beam system with fewer diaphragms is feasible in intelligent construction，but the system without diaphragms places higher demands on the performance of bridge …

3d Reconstruction Method Of Tunnel Surrounding Rock Fracture Based On Vtk, Liu Houxiang, Su Heng

Journal of China & Foreign Highway

Fracture parameters are important reference factors for surrounding rock stability analysis.To realize the visualization analysis of surrounding rock fractures，this paper proposed a three-dimensional （3D） reconstruction method of surrounding rock fractures based on the visualization toolkit （VTK）.Firstly，the collected tunnel surrounding rock images were preprocessed by OpenCV for image grayscale and noise reduction.Secondly，the Otsu method and the open operation in morphology were used to segment the image，and the complete surrounding rock fracture map was obtained.Then，the median method was used to replace the linear interpolation method with the traditional Marching Cubes algorithm in VTK to calculate the equivalent point，and the improved Marching Cubes …

Experimental Study On Deformation Characteristics Of High Liquid Limit Soil Considering The Effect Of Temperature, Li Bangwu, Shen Xuning, Zhang Rui, Chen Yanrong

Journal of China & Foreign Highway

In order to study the influence of temperature on the absorbed bound water and deformation characteristics of high liquid limit soil，the high liquid limit soil in Hunan and Hainan provinces were selected for test.The influence of temperature on the content of bound water was measured by a temperature-controlled water bath volumetric flask test.The consolidation test was carried out on the samples with a one-dimensional temperature-controlled consolidometer，and the variation law of high liquid limit soil deformation affected by temperature was analyzed under the modified pore ratio considering the bound water content.The results show that the absorbed bound water in the high …

Surface Grouting Reinforcement Technology For Shallowly Buried Tunnel In Coastal Zone, Xiang Ze, Deng Shiping, Sheng Zhang, Zhou Ye, Wang Wei, Pei Yabing

Journal of China & Foreign Highway

The Ⅵ level surrounding rock section of a project water intake tunnel is located in the coastal zone，with thick overlying sand layers，broken surrounding rock，and other characteristics.To address these issues，laboratory tests were conducted to explore the effect of water glass volume dosing on the final setting time and strength of cement-sodium silicate （CS） liquid slurry，and field tests were carried out for a comprehensive analysis of grouting methods.The constraint-dispersion mode was finally determined to divide the grouting area into several small grouting units.Advance plastic pipe grouting reinforcement was performed according to the grouting sequence of the outermost circle hole interval first，followed by …

Comparison Analysis Of Different Settlement Prediction Models Under Small Post‑ Constructio N Load On Soft Foundation, Han S Hanpeng, Fu Wei, Zhang Junhui, Lin Chen

Journal of China & Foreign Highway

Settlement deformatio n is a key conc ern in soft foundation construction.Since there is still a small load applied after the filling of soft foundation in the actual project,based on the settlement monitoring data of the high-fill section of Zhaoyang West Ring Expressway in Zhaotong City,Yunnan Province,three settlement prediction methods,namely the hyperbolic method,the three-point method,and the Hoshino method,were used to predict,compare,and analyze the settlement of the fill foundation,and the fitting characteristics of each model were summarized.By comparing the fitting curves and the actual settlement curves,it was found that the loading on the roadbed will cause large errors in the prediction …

Dynamic Response Analysis Of Bridge Under Combined Action Of Random Traffic Flow And Wind Based On Simpack Platform, Xiong Tao, Han Yan, Ma Xingchuan, Li Qianming, Yan Naijie, Zhang Fei, Hu Peng

Journal of China & Foreign Highway

To deal with the time-consuming problem of calculating the dynamic responses of the bridge under the combined action of random traffic flow and wind，a steel box continuous girder bridge was taken as the engineering background，and the finite element model of the bridge and the vehicle model were established in the commercial software Ansys and SIMPACK，respectively.Then，the dynamic responses of the bridge subjected to the single vehicle load，wind loads，and multiple vehicle loads were calculated to verify the superposability of the dynamic responses of the bridge.On this basis，the Monte Carlo method was used to generate the random traffic flow samples.By using the verified …

Research Progress Of Rubber‑Modified Asphalt By Wet Process, Ge Dongdong, Jiang Xiangyang, Lyu Songtao, Zhang Honggang, Song Xiaojin

Journal of China & Foreign Highway

The application of waste tires in asphalt pavements can not only effectively reduce resource consumption but also significantly reduce environmental pollution.Crumb rubber could be obtained by processing waste tires and used as a modifier by mixing with asphalt through the wet process to improve the performance of asphalt.This paper reviewed the research progress of rubber-modified asphalt by wet process and discussed its preparation process，influencing factors of performance，and modification mechanism.By reviewing the relevant studies，the critical conditions in the preparation process and their effects on storage stability were summarized.Furthermore，the effects of rubber dosage，particle size，matrix asphalt type，and preparation parameters on the physical and …

Skid Resistance Detection Technology Of Highway Pavement Based On Tie‑Pavement Coupling Noise, Ye Wei, Chen Fei, Hu Xiaoyang, Xu Zhengwei, Li Liguo

Journal of China & Foreign Highway

In order to improve the skid resistance detection technology of highway pavement，this paper summarized the advantages and disadvantages of the traditional pavement noise measurement methods，adopted the vehicle-following method to collect the tie-pavement coupling noise，and optimized the specific positional parameters of the microphone.The speed correction of the equivalent continuous A-weighted sound level was realized through the fitting of driving speed and equivalent continuous A-weighted sound level.The characteristic signal of the tie-pavement coupling noise was extracted by the principal component analysis method，and it can effectively suppress interference signals such as traffic noise，wind noise，and engine noise.The envelope noise energy （ENE） was obtained by …

Effect Of Corn Stover Oil On Rheological Properties Of Aged Asphalt And Its Regeneration Effect, Cheng Peifeng, Bai Yue, Li Yiming, Zhang Zhanming

Journal of China & Foreign Highway

Corn stover oil，as a kind of bio-oil，is low-carbon and renewable.At the same time，it may restore the performance of aged asphalt.In order to further promote the application of corn stover oil in road engineering，this study explored the effect of corn stover oil as a kind of regeneration agent on the rheological properties of aged asphalt through laboratory experiments and analyzed the regeneration effect.On this basis，the regeneration mechanism of corn stover oil regeneration agent was revealed by using an infrared spectroscopy test and gel permeation chromatography test.The results show that the addition of corn stover oil changes the proportion of aged asphalt …

Research And Practice On Demolition Of Lane Separator In Same Direction Along Zhengzhou‒Luoyang Section Of Lianyungang‒Khorgos Expressway, Zhang Nan, Ji Xiang, Ma Gang

Journal of China & Foreign Highway

In order to solve the problem arising after the demolition and closure of the lane separator in the same direction along the expressway，this paper systematically introduced the reconstruction method of the lane separator in the same direction by studying the overhaul project along Zhengzhou-Luoyang section of Lianyungang‒Khorgos Expressway.The paper explored the main diseases and potential safety hazards existing in the lane separator in the same direction by checking the compliance of specifications，analyzing the traffic operation status，exploring the characteristics of traffic accidents，and investigating the traffic safety facilities.On this basis，it demonstrated the feasibility of demolishing the lane separator in the same direction.According …

Mechanical Properties Of Alkali‑Activated Slag‑Fly Ash Geopolymers, Liu Yang, Wang Jizhao, Lu Naiwei, Wang Bowen

Journal of China & Foreign Highway

In order to respond to the national strategy of energy saving and emission reduction and improve the comprehensive utilization rate of industrial waste，the influence of slag content，alkali equivalent，sodium silicate modulus，and water-cement ratio on the compressive strength of slag-fly ash geopolymers was investigated by single variable and orthogonal experiment method.The compressive strength of geopolymers was analyzed by combining XRD，SEM，and porosity.The results show that the gel formation is promoted with the increase in slag content，and the structure of geopolymers is more compact，which is conducive to the development of strength.After 28 days of standard curing，the influence of various factors on the compressive strength …

Mechanical Properties Of Geopolymer‑Stabilized Recycled Aggregates From Construction Solid Wastes, Yuan Kaixin, He Yongjian, Zhang Laijun, Li Hai, Xu Gewei

Journal of China & Foreign Highway

In order to solve the problem of a sharp increase in construction solid wastes and insufficient utilization rate，this paper took slag-fly ash-based geopolymer as an inorganic binder，replaced natural gravels with recycled aggregates from construction solid wastes，and set urban road base layer as the target scene to study the mechanical properties of geopolymer-stabilized recycled aggregates at different contents.The results show that with the increase in geopolymer content，the maximum dry density of the mixture increases.The optimum moisture content increases.The unconfined compressive strength of the mixture increases with the increase in geopolymer content and curing age and decreases with the increase in recycled …

Comparative Experimental Study On Deformation Characteristics Of High Liquid Limit Soil Under Different Dry And Wet States, Qin Lingwei, Zhang Rui, Li Lu, Xiao Yupeng

Journal of China & Foreign Highway

In order to further reveal the internal mechanism of the influence of solid-like bound water on the deformation characteristics of high liquid limit soil，the difference in the influence of different bound water contents on the deformation of soil samples was analyzed through the comparison of dry and wet sides.Four types of high liquid limit soil with different water contents at the same dry density were used，and a low liquid limit soil was used as a comparison sample to carry out a deformation test.The volumetric flask method was used to test the content of adsorbed bound water in each test soil …

Influence Of Loading Methods On Compression Modulus Of Red Sandstone Soil Solidified With Biological Enzyme And Cement, He Liang, Zhang Haixiang, Guan H Ongxin, Li Huili, Yang Hairong, Liu Hongfu

Journal of China & Foreign Highway

There are various methods to test the modulus of cement-stabilized mixtures.The stiffness performance of cement-stabilized materials will be affected after adding biological enzymes.In order to systematically analyze the influence of loading conditions on the compression modulus of the red sandstone soil solidified with biological enzyme and cement，compressive modulus tests were conducted on the red sandstone soil solidified with biological enzyme and cement by using three static modulus test methods including monotonic loading method of middle section，stepwise loading and unloading method of top surface，and stepwise loading and unloading method of middle section，as well as dynamic modulus method of top surface and …

Optimization Of Mix Proportion For New Jersey Precast Concrete Safety Barriers And Performance Tests Under Integral Concrete Vibrating, Chen Lin, Li Beian, Li Yuanrui, Zhao Zixiang

Journal of China & Foreign Highway

New Jersey safety barriers are the most commonly used form of guardrails in highway median separators due to their excellent safety protection.In response to the cost reduction and quality improvement，efficient and rapid preparation process，and quality issues of New Jersey precast concrete safety barriers，this article adopted the automation production process of New Jersey precast safety barriers，optimized concrete mix proportion for precast safety barriers，and studied their performance.The experimental results show that in the designed C 30 concrete，the compressive strength of the concrete mixed with 15% fly ash reaches 39.2 MPa，and th e slump reaches 185 mm.The concrete performance meets the requirements of …