Civil and Environmental Engineering Commons^™

Translating Soil Salinity To Agricultural Salt Stress: Key Salt-Tolerance Mechanisms For Agrohydrologic Models, Josh Gottlieb, Dvir Ochman, Cheng-Wei Huang, Jean-Christophe Domec, Nimrod Schwartz, Samantha Hartzell

Civil and Environmental Engineering Faculty Publications and Presentations

Summary:

Salt stress has a detrimental impact on crop yield and survival rates, which salt-tolerant cultivars can resist through numerous adaptive mechanisms. Most models of salt stress impacts on productivity and water use employ empirical or simplified schemes to represent salt-adaptive traits. However, with an increased understanding of these physiological tolerance mechanisms and emergent measurement techniques for monitoring key salinity dynamics, the potential for developing mechanistic agrohydrological models of the soil-plant-atmosphere continuum has grown. This perspective highlights strategies for modeling salt tolerance mechanisms, including root system architecture adaptation, salt filtration, adaptation of plant hydraulics, ion compartmentalization, and stomatal responses, to …

Towards A Robust Hydrologic Data Assimilation System For Hurricane-Induced River Flow Forecasting, Peyman Abbaszadeh, Fatemah Gholizadeh, Keyhan Gavahi, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The Hybrid Ensemble and Variational Data Assimilation framework for Environmental Systems (HEAVEN) is a method developed to enhance hydrologic model predictions while accounting for different sources of uncertainties involved in various layers of model simulations. While the effectiveness of this data assimilation in forecasting streamflow has been proven in previous studies, its potential to improve flood forecasting during extreme events remains unexplored. This study aims to demonstrate this potential by employing HEAVEN to assimilate streamflow data from United States Geological Survey (USGS) stations into a conceptual hydrologic model to enhance its capability to forecast hurricane-induced floods across multiple locations within …

Levels Of The Nicotine Analog 6-Methyl Nicotine As A Naturally Formed Tobacco Alkaloid In Tobacco And Tobacco Products, James F. Pankow, Wentai Luo, Kevin J. Mcwhirter, Mohana Sengupta, Robert M. Strongin

Civil and Environmental Engineering Faculty Publications and Presentations

S-6-methyl nicotine (S-6MN) has appeared as a nicotine substitute in commercial electronic e-cigarette products and pouches, including with the claim that such use is not regulated under current U.S. law. This work describes an analytical chemistry based search for the natural S/R presence of 6MN and three other MN compounds in additive-free cured leaf tobaccos and in multiple commercial tobacco products. The samples were extracted using 5 N NaOH, then methyl t-butyl ether. The extracts were analyzed using gas chromatography (GC) with mass spectrometric (MS) detection, and liquid chromatography (LC) with high resolution MS/MS detection. GC peaks with the correct …

Geotechnical Centrifuge Test Of A Pile-Supported Wharf In Silt (Test Aep01), Andrew Earl Parrott

Dissertations and Theses

There have been many documented cases in the U.S. and elsewhere of failure to ports, wharves, and bridges during seismic events due to liquefaction of soils adjacent to foundations. The major design guidelines for surface and maritime transportation structures, such as those offered in ASCE 61-14, Port of Anchorage Seismic Design Manual (POA 2017), AASHTO (2020), Caltrans (2012), and many others, differ considerably on the recommendations for combining the expected inertial and kinematic loads on the pile system. This knowledge gap becomes wider for pile foundations embedded in low plasticity silt, as varying opinions exist on the appropriate characterization of …

Confirmation Of The Scanpyramids North Face Corridor In The Great Pyramid Of Giza Using Multi-Modal Image Fusion From Three Non-Destructive Testing Techniques, Thomas Schumacher, Polina Pugacheva, Hussien Allam, Alejandro Ramirez-Pinero, Benedikt Maier, Johannes Rupfle, Khalid Helal, Olga Popovych, Amr G. Hamza, Mohamed Sholqamy, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

Abstract While non-destructive testing (NDT) measurements have been reported individually for archeological surveys of cultural heritage structures, only a few studies to date have attempted to combine NDT images by means of image fusion (IF). In this article, novel multimodal IF results from three different NDT techniques collected at the Chevron located on the Great Pyramid of Giza (aka. as Khufu’s Pyramid) are presented. The Chevron is an assembly of limestone blocks located in front of the recently confirmed ScanPyramids North Face Corridor (SP-NFC), which had been previously hidden for 4500 years. Under the research activities of the ScanPyramids mission, …

Combining Passive And Active Ultrasonic Stress Wave Monitoring For The Characterization Of The Early-Age Properties Of A Uhpfrc Beam, Numa Bertola, Thomas Schumacher, Ernst Niederleithinger, Eugen Bruhwiler

Civil and Environmental Engineering Faculty Publications and Presentations

This article focuses on the characterization of the early-age properties of Ultra-High-Performance Fiber-Reinforced Cementitious Composite (UHPFRC), which is becoming popular for designing lightweight and durable structures. Due to the large proportion of cement in the mix, the hardening of UHPFRC is significantly faster than conventional concrete. Therefore, the development of UHPFRC properties, such as the elastic modulus, is difficult to monitor as it happens while elements are within the formwork. For this reason, the hydration process of UHPFRC elements is not fully understood yet. A combined passive (or acoustic emission) and active ultrasonic stress wave monitoring approach has the potential …

Life Safety In The Reliability-Based Design And Assessment Of Structures, Mahesh Pandey, Celeste Viljoen, Andrew Way, Katharina Fischer, Miroslav Sykora, Dimitris Diamantidis, Raphael D. J. M. Steenbergen, Niels Lind, Dan M. Frangopol, David Y. Yang, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

We review the developments in life safety and the incorporation thereof in the design and assessment of structures over the last 50 years. Various measures of life safety are presented that have been developed according to the marginal life saving cost principle based on individual, societal and economic considerations. Target probabilities of failure, or target reliabilities, are central to modern structural design and assessment. These are derived either through back-calibration to existing practice or through life cycle cost minimisation, both of which yield comparable safety levels, and are underpinned by lower bounds from life safety. Life cycle cost minimisation is …

Scshm Benchmark Study On Bridge In-Service Structural Monitoring, Maria Pina Limongelli, Doug Thomson, Screenevas Alampalli, Aftab Mufti, Thomas Schumacher, Luca Martinelli, Othmane Lasri, Harry Shenton, Genda Chen, Mohammad Noori, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

The mission of the Society of Civil Structural Health Monitoring (SCSHM, previously known as ISHMII) is to advance the understanding and application of structural monitoring methodologies for the management of civil infrastructure systems. To enable comparative and contrasting studies of various monitoring issues and technologies, the SCSHM Committee on Data-Enhanced Infrastructures Management (DEIMC) identified the need for benchmark problems in the areas of bridge and building structural monitoring. This article reports and briefly discusses the first benchmark study on in-service structural monitoring of bridges that was developed in collaboration with the University of Manitoba, and presents the structure details, study …

Integrating The Interconnections Between Groundwater And Land Surface Processes Through The Coupled Nasa Land Information System And Parflow Environment, Fadji Z. Maina, Dan Rosen, Peyman Abbaszadeh, Chen Yang, Sujay V. Kumar, Matthew Rodell, Reed Maxwell

Civil and Environmental Engineering Faculty Publications and Presentations

Understanding the interactions between the atmosphere, the land, and the subsurface is fundamental to hydrology and is critical for a better assessment of the impacts of climate change and human management on hydrological systems. However, many land surface models simplify the subsurface hydrology and thereby these interactions. In this study, we couple the land surface model Noah‐MP included in the NASA Land Information System (LIS) with the integrated hydrologic model ParFlow (ParFlow‐LIS) using the Earth System Modeling Framework (ESMF) and the National United Operational Prediction Capability (NUOPC). This coupling improves the simulation of water and energy cycle processes by adding …

How Was Your Crossing Experience? Development Of A Pedestrian Satisfaction With Unsignalized Crossings Scale, Seth Lajeunesse, Wesley Kumfer, Sirisha Kothuri, Krista Nordback, Nathan Mcneil

Civil and Environmental Engineering Faculty Publications and Presentations

Unsignalized pedestrian crossing accommodations can improve pedestrian safety, yet their quality of service for pedestrians remains understudied. The present study explored whether and how pedestrians’ satisfaction with crossing unsignalized crossings varied according to the type of crossing accommodation used, that is, the rectangular rapid-flashing beacon (RRFB) with median island, median island alone, marked crosswalk, and unmarked crosswalk. The research team collected intercept survey and video observation data from 358 pedestrians across a total of 40 sites in two different cities. Structural equation models illustrated how pedestrians’ crossing-oriented satisfaction was shaped by their positive perceptions of safety and low levels of …

Risk-Based Methodology For Structural Evaluation Of Bridge-Sized Culverts, David Yang, Kevin White, Timothy Wood

Civil and Environmental Engineering Faculty Publications and Presentations

This report presents the results of the project sponsored by the Federal Highway Administration (FHWA), “Risk Based Methodology for Structural Evaluation of Bridge-Sized Culverts”. The goal of this project was to develop general methodology to (a) quantify uncertainty, especially live load uncertainty, unique to bridge-sized RC box culverts and (b) analyze and calibrate reliability of culverts rated under different rating loads. Over 344 combinations of culvert designs and backfill depths were analyzed based on the AASHTO Manual for Bridge Evaluation as well as the three-dimensional finite element models (FEMs) of the soil-culvert systems. For each combination, a wide range of …

Structural Earthquake Resiliency Of Rocking Core Systems With Floor Enabled Recentering, S. Taban Hajimirza

Dissertations and Theses

The growing need for structural earthquake resiliency, coupled with increasing demands for environmentally sustainable construction, has driven architects and engineers to emphasize the importance of earthquake-resistant mass timber multistory construction in regions prone to high seismic activity. With advancements in building technologies, cross-laminated timber (CLT) has emerged at the forefront of this movement by unlocking new potentials for urban development.

Motivated by the aforementioned demands, this PhD dissertation investigated lateral behavior and earthquake response of a novel lateral force-resisting structural system, known as Floor Recentering Rocking Core (FLR-ROCR). FLR-ROCR is a low-damage recentering mass-timber system that leverages restoring interactions between …

Identification And Analysis On Surface Deformation In The Urban Area Of Nanchang Based On Ps-Insar Method, Mengping Zhang, Jiayi Pan, Peifeng Ma, Hui Lin

Civil and Environmental Engineering Faculty Publications and Presentations

Interferometric Synthetic Aperture Radar (InSAR) technology has emerged as a vital tool for monitoring surface deformation due to its high accuracy and spatial resolution. With the rapid economic development of Nanchang, extensive infrastructure development and construction activities have significantly altered the urban landscape. Underground excavation and groundwater extraction in the region are potential contributors to surface deformation. This study utilized Sentinel-1 satellite data, acquired between September 2018 and May 2023, and applied the Permanent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) technique to monitor surface deformation in Nanchang’s urban area. The findings revealed that surface deformation rates in the study area …

Identifying Opportunities For Nature-Based Solutions With Geospatialized Life Cycle Assessments And Fine-Scale Socioecological Data, Gabriela Shirkey, Annick Anctil, Ranjeet John, Venkatesh Kolluru, Leah Mungai, Herve Kashongwe, Lauren T. Cooper, Ilke Celik, Joshua B. Fisher, Jiquan Chen

Civil and Environmental Engineering Faculty Publications and Presentations

As we increasingly understand the impact that land management intensification has on local and global climate, the call for nature-based solutions (NbS) in agroecosystems has expanded. Moreover, the pressing need to determine when and where NbS should be used raises challenges to socioecological data integration as we overcome spatiotemporal resolutions. Natural and working lands is an effort promoting NbS, particularly emissions reduction and carbon stock maintenance in forests. To overcome the spatiotemporal limitation, we integrated life cycle assessments (LCA), an ecological carbon stock model, and a land cover land use change model to synthesize rates of global warming potential (GWP) …

Sustainability Assessment Of Photovoltaic Cells In Cross-Functional Applications, Achyuth Ravilla

Dissertations and Theses

Achieving the G7 countries' net-zero emissions target by 2050 requires integrating photovoltaic (PV) systems into diverse cross-functional applications that support sustainable energy transitions across multiple sectors. This dissertation explores the economic and environmental sustainability of three such applications: agrivoltaics, lower-dimensional materials in perovskite solar cells, and PV-electrochemical water-splitting technologies for hydrogen production. Employing life cycle assessment (LCA) and techno-economic analysis (TEA), we address the knowledge gap in comprehensive evaluations of PV-integrated solutions.

The first chapter assesses agrivoltaic systems (AVS), which combine PV systems with agriculture to mitigate land-use conflicts while enhancing food and energy production. Findings indicate that AVS designs, …

A Novel Maximum Likelihood Based Probabilistic Behavioral Data Fusion Algorithm For Modeling Residential Energy Consumption, Tanmoy Bhowmik, Naveen Chandra Iraganaboina, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

The current research effort is focused on improving the effective use of the multiple disparate sources of data available by proposing a novel maximum likelihood based probabilistic data fusion approach for modeling residential energy consumption. To demonstrate our data fusion algorithm, we consider energy usage by fuel type variables (for electricity and natural gas) in residential dwellings as our dependent variable of interest, drawn from residential energy consumption survey (RECS) data. The national household travel survey (NHTS) dataset was considered to incorporate additional variables that are not available in the RECS data. With a focus on improving the model for …

Editorial: Advances In Ecological Environment Changes In Coastal And Estuarine Waters In Response To Hydrodynamic Variability, Jiayi Pan, Yeqiang Shu, Zhe-Wen Zheng, Adam T. Devlin, Majid Nazeer, Andrew M. Fischer

Civil and Environmental Engineering Faculty Publications and Presentations

Over the past few decades, coastal and estuarine ecological environments have undergone significant and rapid transformations, driven by a range of factors, with the variability in hydrodynamic conditions being one of the most prominent (Elliott et al., 2019; Statham, 2012; Da et al., 2024). These dynamic forces influence water movement, sediment transport, and nutrient cycling, all of which are critical components affecting the health and stability of these ecosystems (van Vliet et al., 2023; Li et al., 2023). Consequently, understanding and interpreting hydrodynamic processes in coastal and estuarine waters are fundamental to unraveling the mechanisms behind ecological changes. This task …

Exploring The Relationship Between Covid-19 Transmission And Population Mobility Over Time, Tanmoy Bhowmik, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

This study explores the dynamic relationship between COVID-19 transmission and transportation mobility, with an emphasis on understanding the time-varying bidirectional interplay across the different phases of the pandemic. To gain insight into this relationship, we analyzed county-level data on transmission and mobility patterns from the United States over a 74-week period using a comprehensive list of factors including: temporal factors, socio-demographics, health indicators, health care infrastructure attributes, and spatial factors. For our analysis, we proposed a simultaneous econometric model system that explicitly accounts for the bidirectional relationship between COVID-19 transmission and mobility patterns while also accounting for the influence of …

A Systematic Unified Approach For Addressing Temporal Instability In Road Safety Analysis, Kazi Redwan Shabab, Tanmoy Bhowmik, Mohamed H. Zaki, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Multivariate models are widely employed for crash frequency analysis in traffic safety literature. In the context of analyzing data for multiple instances (such as years), it becomes essential to evaluate the stability of parameters over time. The current research proposes a novel approach, labelled the mixed spline indicator pooled model, that offers significant enhancement relative to current approaches employed for capturing temporal instability. The proposed approach entails carefully creating independent variables that allow us to measure parameter slope changes over time and can be easily integrated into existing methodological frameworks. The current research effort compares four multivariate model systems: year …

Comparing The Performance Of Different Missing Data Imputation Approaches In Discrete Outcome Modeling, Md Istiak Jahan, Tanmoy Bhowmik, Lauren Hoover, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Although several approaches exist for data imputation, these approaches are not commonly applied in transportation. The current paper is geared toward assisting transportation researchers and practitioners in developing models using datasets with missing data. The study begins with a data simulation exercise evaluating different solutions implemented for missing data. The dimensions considered in our analysis include: the nature of independent variables, different types of missing variables, different shares of missing values, multiple data sample sizes, and evaluation of single imputation (SI), multiple imputation (MI) and complete case data (CCD) approach. The comparison is conducted by adopting the appropriate inference process …

Predicting Hurricane Evacuation Behavior Synthesizing Data From Travel Surveys And Social Media, Tanmoy Bhowmik, Naveen Eluru, Samiul Hasan, Aron Culotta, Kamol Chandra Roy

Civil and Environmental Engineering Faculty Publications and Presentations

Evacuation behavior models estimated using post-disaster surveys are not adequate to predict real-time dynamic population response as a hurricane unfolds. With the emergence of ubiquitous technology and devices in recent times, social media data with its higher spatio-temporal coverage has become a potential alternative for understanding evacuation behaviour during hurricanes. However, these data are often associated with selection bias and population representativeness issues. To that extent, the current study proposes a novel data fusion algorithm to combine heterogeneous data sources from transportation systems and social media, in a unified framework to understand and predict real-time population response during hurricanes. Specifically, …

Ultrasonic Cigarettes: Chemicals And Cytotoxicity Are Similar To Heated-Coil Pod-Style Electronic Cigarettes., Esther E. Omaiye, Wentai Luo, Kevin J. Mcwhirter, Prue Talbot

Civil and Environmental Engineering Faculty Publications and Presentations

Our purpose was to test the hypothesis that ultrasonic cigarettes (u-cigarettes), which operate at relatively low temperatures, produce aerosols that are less harmful than heated-coil pod-style electronic cigarettes (e-cigarettes). The major chemicals in SURGE u-cigarette fluids and aerosols were quantified, their cytotoxicity and cellular effects were assessed, and a Margin of Exposure risk assessment was performed on chemicals in SURGE fluids. Four SURGE u-cigarette flavor variants ("Blueberry Ice," "Watermelon Ice," "Green Mint," and "Polar Mint") were evaluated. Flavor chemicals were quantified in fluids and aerosols using gas chromatography/mass spectrometry. Cytotoxicity and cell dynamics were assessed using the MTT assay, live-cell …

Examining Driver Injury Severity In Motor Vehicle Crashes: A Copula-Based Approach Considering Temporal Heterogeneity In A Developing Country Context, Shahrior Pervaz, Tanmoy Bhowmik, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Using data from a developing country, the current study develops a copula-based joint modeling framework to study crash type and driver injury severity as two dimensions of the severity process. To be specific, a copula-based multinomial logit model (for crash type) and generalized ordered logit model (for driver severity) is estimated in the study. The data for our analysis is drawn from Bangladesh for the years of 2000 to 2015. Given the presence of multiple years of data, we develop a novel spline variable generation approach that facilitates easy testing of variation in parameters across time in crash type and …

Framework And Methodology For Risk-Based Bridge And Tunnel Asset Management: Objective Risk Assessment And Network Level Evaluation, David Y. Yang, Arash Khosravifar, Diane Moug, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

This report presents the results of the project on establishing a general framework and methodology for risk-based bridge and tunnel asset management. The research was carried out at Portland State University in collaboration with engineers and officials at Oregon Department of Transportation (ODOT) and Federal Highway Administration (FHWA). The primary goal of the research is to achieve risk-based transportation asset management based on (a) objective and consistent risk assessment and (b) effective prioritization and optimization of intervention strategies. Volume I of this report presents methods and findings in the base phase (Phase I) of the project, which is focused on …

Differentiating Dynamic System Outcomes In Cam Photosynthesis Through Sonification, Duncan Turley

Civil and Environmental Engineering Undergraduate Honors Theses

Sonification is a powerful tool that is harnessed by modern engineers to represent information through audio, and is beginning to be used to interpret more complex data sets. Sonification can be used to facilitate the listeners' ability to grasp microscopic or complex changes in the state of a system. This study uses the assigning of sound patterns to model outputs that indicate chaotic or non-chaotic systems in Crassulacean acid metabolism photosynthesis. Using sound allows the interpretation of chaotic data without the more time intensive processes typically used, such as of Fast Fourier Transformations. Based on past research, it is known …

Early Detection Of Structural Damage In Uhpfrc Structures Through The Combination Of Acoustic Emission And Ultrasonic Stress Wave Monitoring, Numa Bertola, Thomas Schumacher, Ernst Niederleithinger, Eugen Brühwiler

Civil and Environmental Engineering Faculty Publications and Presentations

Ultra-High-Performance Fiber-Reinforced Cementitious Composite (UHPFRC) offers several advantages compared to concrete, notably due to the strain hardening behavior under tensile actions. Structures made of this composite material are lightweight and highly durable, thanks to the UHPFRC waterproofing quality. Nonetheless, the tensile behavior leads to a different cracking pattern than conventional concrete and is not fully understood yet. This paper presents a combined approach using both passive ultrasonic (US) stress wave (or acoustic emission) and active US stress wave monitoring to localize and quantify damage progression in a full-scale UHPFRC beam during experimental load testing. The proposed monitoring approach involves 24 …

Advanced Acoustic Emission-Based Shm For Concrete Structures: Real-Time, High-Precision Imaging Of Crack Geometry And Damage Sourcetype Using Moment Tensor Inversion, Seyyedmaalek Momeni, Thomas Schumacher, Lindsay Linzer, Brice Lecampion

Civil and Environmental Engineering Faculty Publications and Presentations

In this paper, we introduce a novel automated and high-precision acoustic emission (AE) monitoring algorithm and the software SIMORGH, which is suitable for structural health monitoring (SHM) of civil structures. Initially developed for laboratory-scale hydraulic fracture monitoring, this core software has been effectively scaled up to meter-level applications and is compatible with heterogeneous media such as concrete. It is designed to work with various standard data formats and is handles both trigger-based and continuous data. We present initial results from implementing this software in the AE monitoring of two 4.88-meter-long concrete beams in a laboratory setting, comparing it with manually …

Combined Passive And Active Ultrasonic Stress Wave Monitoring Of Concrete Structures: An Overview Of Data Analysis Techniques And Their Applications And Limitations, Thomas Schumacher, Numa Bertola, Niklas Epple, Eugen Bruehwiler, Ernst Niederleithinger

Civil and Environmental Engineering Faculty Publications and Presentations

Combined passive ultrasonic (US) stress wave [better known as acoustic emission (AE)] and active US stress wave monitoring has been shown to provide a more holistic picture of ongoing fracture processes, damage progression, as well as slowly occurring aging and degradation mechanisms in concrete structures. Traditionally, different data analysis techniques have been used to analyze the data generated from these two monitoring techniques. For passive US stress wave monitoring, waveform amplitudes, hit rates, source localization, and b-value analysis, among others, have been used to detect and locate cracking. On the other hand, amplitude tracking, magnitude squared coherence (MSC), and coda …

Processes For Depositing Functionalized Nanoparticles Upon A Substrate, Erik T. Thostenson, Thomas Schumacher

Civil and Environmental Engineering Faculty Publications and Presentations

Processes for depositing functionalized nanoparticles upon a non-conductive substrate are disclosed herein. The processes may include the step of aerosolizing one or more particles into suspension within a gas, each of the one or more particles comprising functionalized nanoparticles having an electric charge. The processes may include the step the step of attracting the one or more particles onto a non-conductive substrate by a static electric charge opposite of the electric charge, wherein at least portions of the non-conductive substrate are having the static electric charge. The processes may include the step of depositing the functionalized nanoparticles onto the non-conductive …

Investigation Of Piezocone Dissipation Test Interpretation In Clay Accounting For Vertical And Horizontal Porewater Pressure Dissipation With A Large Deformation Axisymmetric Penetration Model, Diane Moug, Andrew Huffman, Jason T. Dejong

Civil and Environmental Engineering Faculty Publications and Presentations

The piezocone (CPTu) dissipation test is used to characterize how the applied load from the penetrating cone is distributed between the soil and pore fluid during both penetrometer advancement and when penetration is paused. The coefficient of consolidation is often estimated from CPTu dissipation tests by interpreting the rate of excess porewater pressure (∆u) decay to static conditions during a pause in cone penetration. Most CPTu dissipation test interpretation methods are based on Terzaghi consolidation theory for ∆u dissipation at the cone shoulder (u₂ position) or cone face (u₁ position) and assume that radial ∆u dissipation dominates the …