Engineering Commons^™

Analysis Of Mechanical And Deformation Characteristics Of Karst Tunnel Structure And Research On Treatment Technology, Huang Haifeng, Chang Zhenchao, Luo Junhui, Zhou Xiang, Ceng Fuquan, Tian Fapai

Journal of China & Foreign Highway

Combined with the construction process of Nongmo Karst Tunnel on Du’an–Bama Expressway, this paper used Midas-GTS finite element calculation software to conduct numerical simulation research on the stability of surrounding rock and treatment structure of tunnel with karst caves on either side, analyzed the influence of tunnel excavation on the stress and deformation characteristics of surrounding rock and supporting structure, and probed into the treatment effect of biased wall and root pile on the treatment of karst tunnel. The results show that the surrounding rock at the bottom of the tunnel, the top of the composite foundation, and the top …

Effect Of Temperature And Light On Characteristics Of Asphalt Emissions, Zhu Xuwei, Tian Bo

Journal of China & Foreign Highway

In order to study the effects of temperature and light on the characteristics of asphalt emissions, atmospheric pressure chemical ionization–time-of-flight mass spectrometer (APCI‑TOF MS) and electron impact ionization mass spectrometry (EI‑MS) were used to quantitatively characterize the composition information of PG 62-22 asphalt emissions at different temperatures (40–200 °C). The effects of different temperatures and light on total emission factor, SOA conversion factor, intermediate volatile organic compound (IVOC)/semi-volatile organic compound (SVOC) volume fraction, and aromatics volume fraction of asphalt emissions were studied. The results show that the components of asphalt emissions change with temperature, and the components are complex and …

Study On Triaxial Mechanical Properties Of Glass Fiber Reinforced Cement Soil In Short Age, Wang Wei, Dai Mengdan, Yu Wenjie

Journal of China & Foreign Highway

In order to evaluate the improvement effect of fiber on the brittle damage of cement soil, a triaxial unconsolidated undrained (UU) test was carried out on glass fiber cement soil (GCS) with a curing age of 7 d and a mass fraction of glass fiber (GF) of 0, 2‰, 4‰, 6‰, and 8‰, respectively. The results show that: ① GCS retains the original strain softening characteristics of cement soil; ② For the same mass fraction of GF, the peak stress, peak strain, and residual strength of GCS samples increase gradually with the increase in confining pressure, but the brittleness index …

Study On Experimental Application Of Xinjiang Steel Slag In Cement Stabilized Base, Chen Wei, Yu Haiming, Li Qian, Huang Yong, Si Yi

Journal of China & Foreign Highway

Based on the experimental study of Xinjiang steel slag in cement-stabilized base, the physical and chemical characteristics of steel slag were analyzed, and the unconfined compressive strength, splitting strength, and dry shrinkage performance of cement-stabilized steel slag and gravel mixture with different cement dosages (4% and 5%) and steel slag contents (30%, 40%, and 60%) were analyzed. The test results show that steel slag can be used as a good engineering aggregate in a cement-stabilized base, and with the addition of steel slag, the unconfined compressive strength and splitting strength of steel slag and gravel mixture are increased to varying …

Mechanical Properties And Micro Analysis Of Cement Stabilized Steel Slag Macadam Base, Wan Tianbao

Journal of China & Foreign Highway

With steel slag as coarse aggregate, cement-stabilized steel slag macadam base material was designed and prepared by selecting three kinds of cement dosage and three kinds of steel slag content. The mechanical properties of cement-stabilized steel slag macadam base were studied through compaction and unconfined compressive strength tests, and XRD and SEM microscopic tests were carried out to analyze the mineral composition and microscopic morphology of steel slag and mixture and clarify the internal mechanism of hydration product formation and microstructure and strength formation. The results show that the maximum dry density and optimum moisture content of cement-stabilized steel slag …

Analysis Of Influence Of Moisture Content ⁃Temperature Dual Factor On Mechanical Properties Of Red Clay, Wang Jiangtao, Bao Temenbaiyila, Yang Weiguang, Zhou Qi, Fu Helin

Journal of China & Foreign Highway

Under the new climatic environment and engineering construction requirements, engineering problems involving red clay are becoming more and more prominent, and it is urgent to deeply grasp the mechanical and engineering properties of residual slope red clay. The typical red clay in Hunan Province was studied in this paper. Based on the unconsolidated undrained direct shear test, this paper studied the mechanical properties of residual slope red clay under the influence of moisture content and temperature, focusing on the most unfavorable conditions affecting the mechanical properties of red clay. The results show that: ① The shear strength of red clay …

Traffic Conflict Analysis Of Multila Neexpressway Based On Simulation, Ceng Yuekai, Zhou Tao, Chen Yazhen

Journal of China & Foreign Highway

In order to prevent traffic accidents on multi-lane expressways, the VISSIM traffic simulation model was established based on three types of multi-lane traffic conflicts: mixed passenger and cargo type, separated passenger and cargo type, and separated main and auxiliary type. SSAM software was used to obtain traffic conflict data, and the form, quantity, and location of the conflicts were analyzed. The results show that traffic conflicts are the most under the mixed passenger and cargo type, which are mainly distributed in the upper 100 m range of the innermost lane, outermost lane, and deceleration lane. The traffic conflicts under the …

Risk Analysis Of Highway Nighttime Maintenance Operation Based On Sem, Fan Jinhua, Zou Leping, Qi Shaoren, Tian Zhen

Journal of China & Foreign Highway

In order to analyze the factors affecting the risk of nighttime expressway maintenance operation and quantitatively assess the degree of influence of various factors on the risk of nighttime maintenance operation, this paper extracted five first-level indicators and 36 second-level indicators that affect the risk of operation through literature review, accident data, and questionnaire survey and built an evaluation system. The first-order and second-order confirmatory factor analysis models were constructed by using a structural equation model (SEM) based on 343 questionnaires of the nighttime maintenance operation risks. The results show that the driver factor has the greatest effect on the …

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 …

Research On Crack And Permeability Characteristics Of Cement ⁃Modified Expansive Soil Under Dry ⁃Wet Cycles, Bao Guiyong, Xu Yangshaojun, Jiang Zhijie, Rong Hongliu, Wang Jinlong

Journal of China & Foreign Highway

In order to study the engineering permeability characteristics of cement-modified expansive soil under dry and wet cycles, the mix ratio of cement-modified expansive soil was designed, and the orthogonal design test method was adopted. Image analysis software PACS, unconfined compressive strength test, and laboratory permeability test were used to study the crack development, strength attenuation characteristics, and permeability changes of cement-modified expansive soil under dry and wet cycle conditions. The results show that soil permeability and strength are greatly affected by the number of dry and wet cycles. Under the condition of dry and wet cycles, the moisture content of …

Regulating The Size And Assembled Structure Of Graphene Building Blocks For High-Performance Silicon Nanocomposite Anodes, Bo Nie, David Sanchez, Mataz Alcoutlabi, Tengxiao Liu, Saurabh Basu, Soundar Kumara, Gongkai Wang, Hongtao Sun

Mechanical Engineering Faculty Publications

Silicon-based composites have received significant interest as a high-capacity anode material for high-performance lithium-ion batteries. However, the large volume change during prolonged charge/discharge cycles, poor electric conductivity, and unstable solid electrolyte interface of the Si electrodes lead to performance degradations, such as fast capacity decay and low coulombic efficiency (CE). It's promising but challenging to fabricate Si-based composite anodes with a high Si active material, which enables high energy density, high-rate capability, and good cycling stability. Herein, the size effect of mechanically robust and highly conductive graphene sheets was investigated to effectively regulate the charge transport kinetics, volume changes, first …

Analytical Advances In Homeowner Flood Risk Quantification Considering Insurance And Hazard Mitigation, Md Adilur Rahim

LSU Doctoral Dissertations

Accurate economic loss assessment for natural hazards is vital for planning, mitigation, and actuarial purposes. The widespread and costly nature of flood hazards, with the economically disadvantaged disproportionately victimized, makes flood risk assessment and mitigation particularly important. Recent studies have made advancements in assessing flood risk at individual building level. But these methods require solving an integral equation every time the analysis is run, which is computationally intensive. In addition, analyses to date do not consider insurance (i.e., coverage, deductible) information and thus do not estimate the portion of risk that homeowner and insurer bear. Although existing research does consider …

Digital Challenges And Opportunities Of Addressing On-Site Productivity And Safety On Construction Job Sites: An International Perspective, Ahmed Hassan, Ankur Mitra, Mark Mulville, Alan Hore

Conference papers

The slow pace of digital transformation in construction remains an impediment to the industry’s evolution. Despite rapid developments in digital technologies, the vast bulk of data generated on construction job sites remains underutilised due to the limited use of real-time data capture. The diffusion of digital solutions in construction depends on successfully capturing critical real-time data that can inform and contribute to more productive work patterns and safer job sites. Nevertheless, the construction industry’s fragmented nature has segregated the digital solutions offered by technology providers from the volatile challenges facing on-site construction practitioners.

This paper will present the early development …

Wave Attenuation Through Mangrove Forest Using Lidar Representation, Elizabeth Bogan

LSU Master's Theses

Mangrove forests can be found along the world’s intertidal tropical and sub-tropical coastlines. These forested wetlands provide many ecosystem services, including supporting coastal food chains, trapping sediment, and shoreline stabilization. Mangroves are also known for flood damage mitigation by dissipating waves and surge during flooding events. Thus, coastal communities declare a vested interest in the performance of the forest to mitigate flood damage. Physical models using artificial mangrove structures have shown that red mangrove-dominated fringe forests can protect built infrastructure by reducing wave height due to increased drag. One way to estimate the contribution of red mangrove (Rhizophora mangle) prop …

Size Effects In Additively Manufactured Inconel-718 Thin Elements And Cellular Structures, Reem Abdelkarim Abo Znemah

LSU Doctoral Dissertations

A current focus in the additive manufacturing (AM) research community is the production of complex shaped metallic parts and cellular structures. Many researchers went on analyzing and simulating these structures without considering the effect of the element thickness and heterogeneous printing parameters on the resulting material behavior. To advance the application of laser powder bed fusion (LPBF), an AM process, in producing Inconel718 (IN718) complex shaped parts and cellular structures, this study aimed to investigate the effect of thin-walled elements thickness on the mechanical characteristics of both the individual elements and overall cellular structure. A multiscale experimental evaluation of the …

Complex Systems Methods Characterizing Nonlinear Processes In The Near-Earth Electromagnetic Environment: Recent Advances And Open Challenges, Georgios Balasis, Michael A. Balikhin, Sandra C. Chapman, Giuseppe Consolini, Ioannis A. Daglis, Reik V. Donner, Jürgen Kurths, Milan Paluš, Jakob Runge, Bruce T. Tsurutani, Dimitris Vassiliadis, Simon Wing, Jesper W. Gjerloev, Jay Johnson, Massimo Materassi, Tommaso Alberti, Constantinos Papadimitriou, Pouya Manshour, Adamantia Zoe Boutsi, Mirko Stumpo

Faculty Publications

Learning from successful applications of methods originating in statistical mechanics, complex systems science, or information theory in one scientific field (e.g., atmospheric physics or climatology) can provide important insights or conceptual ideas for other areas (e.g., space sciences) or even stimulate new research questions and approaches. For instance, quantification and attribution of dynamical complexity in output time series of nonlinear dynamical systems is a key challenge across scientific disciplines. Especially in the field of space physics, an early and accurate detection of characteristic dissimilarity between normal and abnormal states (e.g., pre-storm activity vs. magnetic storms) has the potential to vastly …

Computational Design Of Electro-Organocatalysts And Transition Metal Sulfides For The Electrochemical Reduction Of Co2, Foroogh Khezeli

LSU Doctoral Dissertations

Abstract

Electrochemical CO₂ reduction (ECO₂RR) has emerged as a promising approach for generating carbon-neutral liquid fuels by utilizing excess renewable electricity to convert CO₂. This thesis aims to employ atomistic simulations by using Density Functional Theory (DFT) to investigate the mechanistic details of how transition metal sulfides and electro-organocatalysts can enhance the activity and selectivity towards desired products, including those containing C-H bonds and molecules with C-C bonds. For this project, three different electrocatalysts were designed computationally.

Firstly, MoS₂ was chosen as a transition metal sulfide catalyst with the objective of understanding the kinetics …

Controls On The Stratiform Copper Mineralization In The Western Syncline, Upper Peninsula, Michigan, William C. Williams, Theodore J. Bornhorst

Michigan Tech Publications

The Western Syncline hosts reduced-facies, or Kupferschiefer-type, sedimentary rock-hosted stratiform Cu deposits (SSC) in the lowermost meters of the Nonesuch Formation, which is part of a thick section of clastic sedimentary rocks that comprise the upper fill of the Mesoproterozoic Midcontinent Rift of North America. Located in the Porcupine Mountains Cu district in Upper Peninsula, Michigan, these blind deposits were discovered in 1956, but are not yet developed, although recent renewed interest may result in near-term production. The deposits are distinguished by their relatively undeformed nature and lack of superposed hydrothermal events. Prior to lithification, chalcocite mineralization replaced diagenetic pyrite …

Measurements Of Scintillation Light Quenching For Protons In Rare-Earth Inorganic Scintillators, Tatiana Nathaly Espinoza

Nuclear Engineering ETDs

Scintillator detectors have become a leading choice of radiation detectors for a variety of applications, including space science. Due to their intrinsic characteristics, rare-earth inorganic scintillators provide the capability to detect both gamma and charged particles in a small detector. The response of these detectors is typically characterized using isotropic gamma sources. However, the light output produced in the scintillator from an incident gamma of a particular energy differs from the light output produced from an incident charged particle of the same energy; a phenomenon known as quenching. Using two types of rare-earth inorganic scintillators, Y2SiO5(YSO:Ce), and Gd₃Al₂Ga₃O₁₂(GAGG:Ce), we measured …

Exploration Of Efficient Dewatering Methods In Stimulus-Responsive Hydrogels And Their Potential For Desalination, Weiliang Sun

LSU Doctoral Dissertations

Addressing global freshwater scarcity is a pressing challenge, and desalination has emerged as a viable solution to generate high-quality water without compromising natural freshwater ecosystems. In comparison to conventional desalination methods such as thermal distillation and membrane-based processes, hydrogels offer distinct advantages including strong water absorption, water retention, well-defined pore structures, customizable functional groups, and responsive properties to external stimuli. These unique characteristics position hydrogels as promising candidates for water treatment applications. Hydrogel-based desalination involves the utilization of hydrogels to absorb water from saltwater, and then discharge low-concentration solutions to obtain reclaimed water. The fundamental principle underlying the desalination ability …

Ecg Recordings As Predictors Of Very Early Autism Likelihood: A Machine Learning Approach, Deepa Tilwani, Jessica Bradshaw, Amit Sheth, Christian O'Reilly

Publications

In recent years, there has been a rise in the prevalence of autism spectrum disorder (ASD). The diagnosis of ASD requires behavioral observation and standardized testing completed by highly trained experts. Early intervention for ASD can begin as early as 1–2 years of age, but ASD diagnoses are not typically made until ages 2–5 years, thus delaying the start of intervention. There is an urgent need for non-invasive biomarkers to detect ASD in infancy. While previous research using physiological recordings has focused on brain-based biomarkers of ASD, this study investigated the potential of electrocardiogram (ECG) recordings as an ASD biomarker …

The Characteristics Of Successful Military It Projects: A Cross-Country Empirical Study, Helene Berg, Jonathan D. Ritschel

Faculty Publications

In the armed forces, successful digitalization is crucial to ensure effective operations. Much of the existing literature on project factors during the planning and execution phases of public IT projects do not focus specifically on military sector projects. Therefore, the paper aims to provide empirical insights into the characteristics of successful military IT projects. Data from such projects in NATO countries and agencies were collected through interviews and project documents. The findings relating to the main variable of interest, “delivery of client benefit,” supported previous findings on IT project performance. Medium-sized projects performed better than small and large projects, and …

Multiple Ways To Implement And Infer Sentience, Nicolas Rouleau, Michael Levin

Animal Sentience

Segundo-Ortin & Calvo’s (S&C’s) thorough review of “plant neurobiology” presents evidence supporting the possibility of plant sentience. They make a compelling case that plants anticipate, assess risk, cooperate, mimic, and pursue goals, as do their animal counterparts. S&C point out that there is a double standard: behavioural patterns associated with subjective experiences in humans are considered valid for inferring cognition in non-human animals but not in diverse other systems including plants. We argue that cognitive functions, including sentience, can potentially be achieved by very different systems and their disparate substrates. We offer some context from the basal cognition literature and …

Mitigating Landslide Hazards In Qena Governorate Of Egypt: A Gis-Based Neutrosophic Paprika Approach, Nabil M. Abdelaziz, Safa Al-Saeed

Neutrosophic Systems with Applications

This paper presents a novel approach to landslide susceptibility assessment in the Qena Governorate, Egypt, integrating the neutrosophic Multi-Criteria Decision-Making (MCDM) method, the Potentially All Pairwise RanKings of all possible Alternatives (PAPRIKA), and the ArcGIS weighted overlay technique. The research focuses on the quantification and prioritization of eight criteria: slope, aspect, proximity to road, soil type, proximity to river, land cover, elevation, and Lithology. These factors are evaluated under the uncertainty and indeterminacy of the neutrosophic environment by employing the PAPRIKA method. The results of the analysis are visualized and interpreted using ArcGIS weighted overlay, offering spatially explicit insights into …

Tailoring The Inherent Properties Of Biobased Nanoparticles For Nanomedicine, Alap Ali Zahid, Aishik Chakraborty, Wei Luo, Ali Coyle, Arghya Paul

Chemical and Biochemical Engineering Publications

Biobased nanoparticles are at the leading edge of the rapidly developing field of nanomedicine and biotherapeutics. Their unique size, shape, and biophysical properties make them attractive tools for biomedical research, including vaccination, targeted drug delivery, and immune therapy. These nanoparticles are engineered to present native cell receptors and proteins on their surfaces, providing a biomimicking camouflage for therapeutic cargo to evade rapid degradation, immune rejection, inflammation, and clearance. Despite showing promising clinical relevance, commercial implementation of these biobased nanoparticles is yet to be fully realized. In this perspective, we discuss advanced biobased nanoparticle designs used in medical applications, such as …

Effect Of Internal Curing And Shrinkage-Mitigating Materials On Microstructural Characteristics Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Internal curing (IC) and other shrinkage mitigating materials are employed to reduce shrinkage and risk of cracking. This study investigates the efficiency of individual versus combined use of IC and shrinkage mitigating materials on key characteristics of fiber-reinforced mortar (FRM). The investigated mixtures include a 25% pre-saturated lightweight sand (LWS) that is added individually and combined with 10% CaO-based expansive agent (EA) and 2% shrinkage reducing admixture (SRA). This elucidates the synergistic effect of high content IC and EA/SRA on macro- and micro-mechanical characteristics of FRM, especially at the interface of the matrix with fibers. Mechanical properties, microstructural characteristics, and …

Effects Of Poloxamers As Excipients On The Physicomechanical Properties, Cellular Biocompatibility, And In Vitro Drug Release Of Electrospun Polycaprolactone (Pcl) Fibers, Addison Fagile, Rachel Emerine, Shih-Feng Chou

Mechanical Engineering Faculty Publications and Presentations

Electrospun microfibers are emerging as one of the advanced wound dressing materials for acute and/or chronic wounds, especially with their ability to carry drugs and excipients at a high loading while being able to deliver them in a controlled manner. Various attempts were made to include excipients in electrospun microfibers as wound dressing materials, and one of them is poloxamer, an amphiphilic polymer that exhibits wound debridement characteristics. In this study, we formulated two types of poloxamers (i.e., P188 and P338) at 30% (w/w) loading into electrospun polycaprolactone (PCL) fibers to evaluate their physicomechanical properties, biocompatibility, and in vitro drug …

Triverus Infiltration And Cleaning Report 2023, Unh Stormwater Center

UNH Stormwater Center

No abstract provided.

Neural Network Models For Generating Synthetic Flight Data, Nathaniel Sisson

Doctoral Dissertations and Master's Theses

Flight test data is a valuable resource used in many aerospace applications. However, procuring a sufficiently large database of flight test data poses several challenges. Nominal flight tests can be expensive and time-consuming and require much post-processing depending on the availability of sensors and the quality of the sensor output. Flight test performed outside of nominal flight conditions, or flight tests in which failures are introduced, add to the inherent risk and danger associated with flight tests. The most popular alternative to flight test, numerical simulations, may fail to fully capture all non-linear behavior. While flight tests will always be …

Quantifying Uncertainties In Direct-Numerical-Simulation Statistics Due To Wall-Normal Numerics And Grids, Peng E. S. Chen, Xiaowei Zhu, Yipeng Shi, Xiang I. A. Yang

Mechanical and Materials Engineering Faculty Publications and Presentations

This paper takes the perspective of a user of direct-numerical-simulation (DNS) data and quantifies the uncertainties in DNS statistics for plane channel flows. We focus on high-order statistics, such as skewness, kurtosis, and viscous dissipation, and quantify the uncertainties due to wall-normal numerics and grids while minimizing the sampling error and the discretization error in the wall-parallel directions. Two grid distributions and four discretization methods are considered, which are representative of the existing DNSs. Our results show that the available DNS data contain at least a 7% uncertainty in the computed mean viscous dissipation in the buffer layer. Moreover, since …