Engineering Commons^™

Exploring The Impact Of Socio-Demographic Characteristics, Health Concerns, And Product Type On Home Delivery Rates And Expenditures During A Strict Covid-19 Lockdown Period: A Case Study From Portland, Or, Miguel Figliozzi, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

E-commerce volumes and home deliveries have experienced steady growth in the last two decades. Strict COVID-19 lockdowns made home delivery an essential service and a lifeline for many households that, for travel restrictions or health concerns, were not able to utilize traditional shopping methods. This research studies the impact of socio-demographic variables and e-commerce attitudes on household deliveries for seven product categories (groceries, meals, electronics, household and office goods, recreational items, and fashion, beauty and personal care products, and medicine/health-related products) during the lockdown period in the greater Portland metropolitan region. To understand these impacts, exploratory factor analysis and …

An Investigation Of The Potential Adoption Of Anaerobic Digestion For Energy Production In Irish Farms, Niamh Power, Sean O'Connor, Ehiaze Ehimen, Suresh C. Pillai, Gary A. Lyons, John Bartlett

Publications

Anaerobic digestion (AD) has been recognised as an effective means of simultaneously producing energy while reducing greenhouse gas (GHG) emissions. Despite having a large agriculture sector, Ireland has experienced little uptake of the technology, ranking 20th within the EU-28. It is, therefore, necessary to understand the general opinions, willingness to adopt, and perceived obstacles of potential adopters of the technology. As likely primary users of this technology, a survey of Irish cattle farmers was conducted to assess the potential of on-farm AD for energy production in Ireland. The study seeks to understand farmers’ motivations, perceived barriers, and preferred business model. …

Accurate Measurement Of Healthy Joint Kinematics To Inform Diagnosis And Treatment, Vasiliki Kefala

Electronic Theses and Dissertations

The description of human motion has a primary importance in different scientific areas such as medicine, sports, physical therapy. Kinematics specifically studies pure motion without reference to the causes of motion such as forces. Understanding the kinematics of human movement is of critical importance in medicine and biology. Motion measure­ment can be used in order to to evaluate functional performance of limbs under normal and abnormal conditions. Kinematic knowledge is also important for diagnosis and surgi­cal treatment of joint disease and the design of implants to rehabilitate function. Accurate joint kinematics is essential to protect articular functionality. An alteration may …

Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang

Electronic Theses and Dissertations

Cemented and cementless fixation in total knee arthroplasty (TKA) have been successfully used for decades. As the number of younger and more active patients treated with TKA continues to increase, long-term implant survivorship is of increasing importance. One of the most common complications and hence the reason for revision is mechanical loosening (23.1% of all revised TKA). The loosening mechanisms have been proposed for different fixation types. For cemented fixation, bone remodeling after surgery is regulated by the changes in strain energy density (SED). The recruitment of osteoclasts and osteoblasts is controlled by SED-related signals. Insufficient stimuli can promote bone …

Cybersecurity Analysis Of Load Frequency Control In Power Systems: A Survey, Sahaj Saxena, Sajal Bhatia, Rahul Gupta

School of Computer Science & Engineering Faculty Publications

Today, power systems have transformed considerably and taken a new shape of geographically distributed systems from the locally centralized systems thereby leading to a new infrastructure in the framework of networked control cyber-physical system (CPS). Among the different important operations to be performed for smooth generation, transmission, and distribution of power, maintaining the scheduled frequency, against any perturbations, is an important one. The load frequency control (LFC) operation actually governs this frequency regulation activity after the primary control. Due to CPS nature, the LFC operation is vulnerable to attacks, both from physical and cyber standpoints. The cyber-attack strategies ranges from …

Nanomaterials In The Environment, Human Exposure Pathway, And Health Effects: A Review, Arindam Malakar, Sushil R. Kanel, Chittaranjan Ray, Daniel D. Snow, Mallikarjuna N. Nadagouda

Daugherty Water for Food Global Institute: Faculty Publications

Nanomaterials (NMs), both natural and synthetic, are produced, transformed, and exported into our environment daily. Natural NMs annual flux to the environment is around 97% of the total and is significantly higher than synthetic NMs. However, synthetic NMs are considered to have a detrimental effect on the environment. The extensive usage of synthetic NMs in different fields, including chemical, engineering, electronics, and medicine, makes them susceptible to be discharged into the atmosphere, various water sources, soil, and landfill waste. As ever-larger quantities of NMs end up in our environment and start interacting with the biota, it is crucial to understand …

Baseflow Nitrate Dynamics Within Nested Watersheds Of An Agricultural Stream In Nebraska, Usa, Galen Richards, Troy E. Gilmore, Aaron R. Mittelstet, Tiffany Messer, Daniel D. Snow

Daugherty Water for Food Global Institute: Faculty Publications

There is a need to evaluate high surface nitrate concentrations across agricultural watersheds, both spatially and temporally, to increase understanding of source and timing of nitrogen loads in streams and rivers. Bazile Creek is a high-nitrate stream originating in the agriculturally intensive Bazile Groundwater Management Area of Eastern Nebraska, USA. It is a gaining stream that receives groundwater with high nitrate concentrations originating from nonpoint sources. The objective of this study was to determine spatial and temporal variability of baseflow nitrate concentrations in Bazile Creek and its tributaries and to relate this variability to watershed characteristics. Surface-water nitrate samples were …

Surveillance Of Plasticizers, Bisphenol A, Steroids And Caffeine In Surface Water Of River Ganga And Sundarban Wetland Along The Bay Of Bengal: Occurrence, Sources, Estrogenicity Screening And Ecotoxicological Risk Assessment, Paromita Chakraborty, Nancy W. Shappell, Moitraiyee Mukhopadhyay, Sathaporn Onanong, Daniel D. Snow

Daugherty Water for Food Global Institute: Faculty Publications

The transboundary River Ganga serves as a conduit for meltwater from the Himalayas and is a major freshwater source for two thirds of Indian population before emptying into the Sundarban Delta, the largest estuary in the Bay of Bengal. Endocrine disrupting compounds (EDCs) such as phthalic acid esters (PAEs) and bisphenol A (BPA) used as organic plastic additives can pollute the aquatic environment receiving plastic litter. Hence, we have investigated these EDCs in water samples from Ganga and Sundarban wetland of India. Since these compounds exhibit estrogenic potential, we have further measured steroids and evaluated the estrogenic activity (estradiol equivalents, …

Transmission Routes Of The Microbiome And Resistome From Manure To Soil And Lettuce, Yuepeng Sun, Daniel D. Snow, Harkamal Walia, Xu Li

Daugherty Water for Food Global Institute: Faculty Publications

The land application of animal manure can introduce manure microbiome and resistome to croplands where food crops are grown. The objective of this study was to characterize the microbiome and resistome on and in the leaves of lettuce grown in manured soil and identify the main transmission routes of microbes and antibiotic resistance genes (ARGs) from soil to the episphere and endosphere of lettuce. Shotgun metagenomic results show that manure application significantly altered the composition of the microbiome and resistome of surface soil. SourceTracker analyses indicate that manure and original soil were the main source of the microbiome and resistome …

An Estimate Of The Pitting Strength Of Steel Materials, Edward E. Osakue, Lucky Anetor, Kendall Harris

Faculty Publications

A single expression for estimating the nominal pitting strength of steel materials, based on surface hardness, is developed from first principles for a reliability of 99% at 107 load cycles. It requires the hardness values to be measured in Vicker’s hardness scale. The expression may be used for any steel material processed by hot rolling, cold drawing, quenching and tempering or case-hardening. The formulation incorporates a nominal design factor at 99% reliability which is estimated from a probabilistic model based on the lognormal probability density function. Pitting strength estimates from the expression are compared with those of American Gear Manufacturers …

Kinetics Study Of The Hydrodeoxygenation Of Xylitol Over A ReoX-Pd/Ceo2 Catalyst, Blake Macqueen, Michael Royko, Bradie S. Crandall, Andreas Heyden, Yomaira J. Pagán-Torres, Jochen A. Lauterbach

Faculty Publications

In this study, we elucidate the reaction kinetics for the simultaneous hydrodeoxygenation of xylitol to 1,2-dideoxypentitol and 1,2,5-pentanetriol over a ReOx-Pd/CeO2 (2.0 weight% Re, 0.30 weight% Pd) catalyst. The reaction was determined to be a zero-order reaction with respect to xylitol. The activation energy was elucidated through an Arrhenius relationship as well as non-Arrhenius kinetics. The Arrhenius relationship was investigated at 150–170◦ C and a constant H2 pressure of 10 bar resulting in an activation energy of 48.7 ± 10.5 kJ/mol. The investigation of non-Arrhenius kinetics was conducted at 120–170◦ C and a sub-Arrhenius relation was elucidated with activation energy …

Microstructural And Chemical Characterization Of A Purple Pigment From A Faiyum Mummy Portrait, Glenn Gates, Yaqiao Wu, Jatuporn Burns, Jennifer Watkins, Darryl P. Butt

Materials Science and Engineering Faculty Publications and Presentations

Results are presented from analyses that were conducted to explain the presence of chromium, detected noninvasively using energy-dispersive X-ray fluorescence (XRF), in the unusually large (2-3mm diameter) rough gem-like purple pigment particles in the paint used for a Faiyum mummy portrait. An approximately 50 μm diameter particle of the chromium-containing purple pigment was extracted from the Portrait of a Bearded Man, dated to Roman Imperial Egypt in the second century, circa 170-180 CE, accession #32.6 in the Walters Art Museum collection. The particle was characterized using energy-dispersive X-ray fluorescence analysis, electron microscopy, diffraction, and atom probe tomography. It is …

Influence Of The Inas Coverage On The Performance Of Submonolayer-Quantum-Dot Infrared Photodetectors Grown With A (2×4) Surface Reconstruction, Ahmad Alzeidan, Tiago F. De Cantalice, Kevin D. Vallejo, Paul J. Simmonds, Alain A. Quivy

Materials Science and Engineering Faculty Publications and Presentations

Two infrared photodetectors based on submonolayer quantum dots, having a different InAs coverage of 35% and 50%, were grown, processed and tested. The detector with the larger coverage yielded a specific detectivity of 1.13×10 ¹¹ cm Hz ^1/2 W ^-1 at 12K, which is among the highest values reported in the literature for that kind of device.

Low-Level Groundwater Atrazine In High Atrazine Usage Nebraska Counties: Likely Effects Of Excessive Groundwater Abstraction, Moses New-Aaron, Olufemi Abimbola, Raheleh Mohammadi, Oluwaseun Famojuro, Zaeema Naveed, Azar Abadi, Jesse E. Bell, Shannon Bartelt-Hunt, Eleanor G. Rogan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting …

Improvements In Sub-Catchment Fractional Snowpack And Snowmelt Parameterizations And Hydrologic Modeling For Climate Change Assessments In The Western Himalayas, Vishal Singh, Francisco Muñoz-Arriola

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The present work proposes to improve estimates of snowpack and snowmelt and their assessment in the steep Himalayan ranges at the sub-catchment scale. Temporal variability of streamflow and the associated distribution of accumulated snow in catchments with glacier presence in the Himalayas illustrates how changes in snowpack and snowmelt can affect the water supply for local water management. The primary objective of this study is to assess the role of elevation, temperature lapse rate (TLR), and precipitation lapse rate (PLR) in the computation of snowpack (or snowfall) and snowmelt in sub-catchments of the Satluj River basin. Modeling of snowpack and …

การประเมินรูปแบบธุรกิจสับเปลี่ยนแบตเตอรี่สำหรับจักรยานยนต์ไฟฟ้าในประเทศไทย, นันทพงศ์ นิรมลนุรักษ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

การสับเปลี่ยนแบตเตอรี่ (Battery Swapping) จะมาส่งเสริมและสนับสนุนอุตสาหกรรมยานยนต์ไฟฟ้า โดยเฉพาะกลุ่มจักรยานยนต์ไฟฟ้า (Electric Motorcycles) เนื่องจากจักรยานยนต์ไฟฟ้าต้องใช้เวลาในการเติมพลังงานนานกว่าจักรยานยนต์ (Motorcycles) การสับเปลี่ยนแบตเตอรี่จึงเป็นสิ่งที่จะมาแก้ปัญหาเรื่องนี้ แต่เนื่องจากรูปแบบธุรกิจนี้ยังอยู่ในช่วงส่งเสริมและผลักดัน งานวิจัยนี้จึงมีวัตถุประสงค์เพื่อวิเคราะห์ความเป็นไปได้ของธุรกิจสับเปลี่ยนแบตเตอรี่ในประเทศไทย โดยการวิเคราะห์เชิงคุณภาพเพื่อนำองค์ประกอบต่างๆที่มีผลต่อการดำเนินธุรกิจด้วย โมเดลสำหรับการวิเคราะห์ธุรกิจ (Business model canvas) และ การวิเคราะห์ความเป็นไปได้ทางการเงินด้วยการคิดลดกระแสเงินสด (Discount Cash Flow) เพื่อประเมินความคุ้มค่าในการลงทุนธุรกิจนี้ 4 รูปแบบกรณีศึกษา คือ รูปแบบปกติ, รูปแบบที่มีอัตราการใช้บริการสูง, รูปแบบที่ได้รับการสนับสนุนเงินลงทุน และ รูปแบบที่เทคโนโลยีมีการพัฒนาอย่างรวดเร็ว โดยผลจากการวิเคราะห์เชิงธุรกิจ มีองค์ประกอบต่างๆ ที่เหมาะสมในประเทศไทย ซึ่งอยู่บนพื้นฐานความต้องการของผู้ใช้บริการ อาทิเช่น การจัดโปรโมชั่นต่างๆ การพัฒนาระบบซอฟแวร์ หรือ การมีตัวเลือกในการใช้บริการ เป็นต้น และผลจากการวิเคราะห์ทางด้านการเงิน แสดงให้เห็นว่าการลงทุนในรูปแบบที่มีการปรับอัตราการใช้บริการ (Utilization rate) ที่ 21%, การได้รับเงินสนับสนุน อย่างน้อย 25% ของต้นทุนดำเนินงาน และ การใช้เทคโนโลยีในการผลิตแบตเตอรี่ส่งผลให้ต้นทุนดำเนินงานลดลง 37% ทำให้โครงการมีความคุ้มค่าในการลงทุน ซึ่งมีมูลค่าปัจจุบันสุทธิ, อัตราผลตอบแทนภายใน และระยะเวลาคืนทุนที่แตกต่างกัน เนื่องจากปัจจัยต้นทุนและผลประโยชน์ของแต่ละรูปแบบกรณีศึกษาที่แตกต่างกัน เพื่อเป็นแนวทางในการศึกษาต่อไป ข้อเสนอแนะบางประการได้รับการเสนอให้พิจารณาปัจจัยอื่นๆเพิ่มเติมเพื่อส่งเสริมการพัฒนาธุรกิจ และสามารถนำไปใช้อ้างอิงสำหรับผู้มีอำนาจในการตัดสินใจและนักลงทุน

Simultaneous Wound Border Segmentation And Tissue Classification Using A Conditional Generative Adversarial Network, Salih Sarp, Murat Kuzlu, Manisa Pipattanasomporn, Ozgur Guler

Engineering Technology Faculty Publications

Generative adversarial network (GAN) applications on medical image synthesis have the potential to assist caregivers in deciding a proper chronic wound treatment plan by understanding the border segmentation and the wound tissue classification visually. This study proposes a hybrid wound border segmentation and tissue classification method utilising conditional GAN, which can mimic real data without expert knowledge. We trained the network on chronic wound datasets with different sizes. The performance of the GAN algorithm is evaluated through the mean squared error, Dice coefficient metrics and visual inspection of generated images. This study also analyses the optimum number of training images …

The Enlightening Role Of Explainable Artificial Intelligence In Chronic Wound Classification, Salih Sarp, Murat Kuzlu, Emmanuel Wilson, Umit Cali, Ozgur Guler

Engineering Technology Faculty Publications

Artificial Intelligence (AI) has been among the most emerging research and industrial application fields, especially in the healthcare domain, but operated as a black-box model with a limited understanding of its inner working over the past decades. AI algorithms are, in large part, built on weights calculated as a result of large matrix multiplications. It is typically hard to interpret and debug the computationally intensive processes. Explainable Artificial Intelligence (XAI) aims to solve black-box and hard-to-debug approaches through the use of various techniques and tools. In this study, XAI techniques are applied to chronic wound classification. The proposed model classifies …

Opportunistic Maintenance Strategy Of A Heave Compensation System For Expected Performance Degradation, Chao Zhang, Yujie Qian, Hongyan Dui, Shaoping Wang, Rentong Chen, Mileta M. Tomovic

Engineering Technology Faculty Publications

In the marine industry, heave compensation systems are applied to marine equipment to compensate for the adverse effects of waves and the hydraulic system is usually used as the power system of heave compensation systems. This article introduces importance theory to the opportunistic maintenance (OM) strategy to provide guidance for the maintenance of heave compensation systems. The working principle of a semi-active heave compensation system and the specific working states of its hydraulic components are also first explained. Opportunistic maintenance is applied to the semi-active heave compensation system. Moreover, the joint integrated importance measure (JIIM) between different components at different …

Development Of An Undergraduate Welding Laboratory For Research And Education, Hamid Eisazadeh, Alok K. Verma

Engineering Technology Faculty Publications

The shortage of welders in Hampton Roads area, where many shipyards are located, is becoming severe for shipbuilding in coming years. Many welding engineers graduated from universities located out of state, tend to go back to companies near their home, after receiving couple years of welding experience at Hampton Roads shipyards. Therefore, it is critical to train local welders. In order to address the welding workforce needs of Hampton Roads, the Department of Engineering Technology at Old Dominion University has recently launched an initiative for developing a laboratory for welding processes (LWP) for supporting educational and research activities in its …

Pedagogical Methods And Advances For Synchronous/Asynchronous Instruction Of Laboratories In Engineering Technology Programs, Nestor Escobales, Alok Verma

Engineering Technology Faculty Publications

Significant research has been done on the subject of distance learning (DL) instruction for many academic disciplines. However, when it comes to engineering technology (ET) programs, particularly, engineering laboratory work, limited studies are available. It is unquestionable that engineering laboratory work is essential for the successful preparation of individuals enrolled in ET programs. The focus of ET programs is on the correct use and application of engineering principles with a direct focus on practical application rather than on theory alone. The difficulties increase significantly when laboratories are offered in DL mode, particularly for ET programs. It is well known that …

Engineering Technology Programs Outreach To K-12, Alok Verma

Engineering Technology Faculty Publications

The Engineering Technology (ET) degree emphasizes hands-on application and implementation. Graduates holding this degree play a valuable role in economically growing the US and keeping it internationally competitive. However, “engineering and engineering technology, are widely misunderstood… the public sector (employers, students, high-school counselors, politicians and the general public) needs to be educated as to the particular value of each,” according to Engineering.com [1]. The National Academy of Engineering states, “Unlike the much better-known field of engineering, engineering technology is unfamiliar to most Americans and goes unmentioned in most policy discussions about the US technical workforce. This is even though workers …

Mentoring Prospective Engineering Students Through The After School Program "Girls In Engineering" Focused On Building An Underwater Remotely Operated Vehicle, Vukica M. Jovanović, Deborah Marshall, Jeff Warren Larson Jr., Abdul Rahman Badawi, Neil R. Stclair, Otilia Popescu, Murat Kuzlu, Petros J. Katsioloudis, Linda Vahala, Michael Anthony Crespo

Engineering Technology Faculty Publications

A number of studies by engineering education researchers have pointed out that all-female teams, rather than mixed teams, result in better forms of participation and interaction in engineering related after-school programs and clubs. In particular, for after-school programs or clubs that form in response to a STEM competition, all-female teams have better chances of developing. One such competition, which will be discussed in this paper, is a regional Marine Advanced Technology Education (MATE) competition in which students from Blind_Review High School have been participating for many years.For each year’s competition, an all-female team of students enrolled in the Career and …

Biocybersecurity: A Converging Threat As An Auxiliary To War, Lucas Potter, Orlando Ayala, Xavier-Lewis Palmer

Engineering Technology Faculty Publications

Biodefense is the discipline of ensuring biosecurity with respect to select groups of organisms and limiting their spread. This field has increasingly been challenged by novel threats from nature that have been weaponized such as SARS, Anthrax, and similar pathogens, but has emerged victorious through collaboration of national and world health groups. However, it may come under additional stress in the 21st century as the field intersects with the cyberworld-- a world where governments have already been struggling to keep up with cyber attacks from small to state-level actors as cyberthreats have been relied on to level the playing field …

Osteocyte Activity And Skeletal Muscle Relative Gene Expression Profiling After Short-Term Muscle Paralysis, Michelle Gelbs

Dissertations and Theses

Mechanical loading is essential for maintaining bone tissue. Reduced mechanical loading has been shown to have a negative effect on bone, and can result in the development of disuse osteoporosis. Disuse models of muscle inactivity and immobilization, like the Botox model used in this study, result in changes in the bone microarchitecture, the mechanisms behind which are not fully understood. In a previous four-week Botox disuse study, skeletally mature 20- week-old rats experienced degradation of intracortical bone, increased vascular porosity, and decreased osteocyte lacunar density in the tibiae. The focus of this study was to explicate a potential source of …

On The Improvements Of Boundary-Layer Representation For High Resolution Weather Forecasting In Costal-Urban Environments, David Melecio-Vazquez

Dissertations and Theses

As large urban centers around the world become more densely populated, the global conversion from natural to man-made land surfaces will only increase. These land-use changes affect the urban surface energy budget which in turn changes the structure of the planetary boundary layer (PBL) above. With current high-performance computing systems, meteorological and built environment information can be better utilized to quantify the anthropogenic effects of these modifications. Although these systems have improved forecasting near-surface weather conditions, a comprehensive approach to represent urban impacts on the PBL is still limited. Improved PBL representation can lead to better weather and climate forecasts, …

Analyzing Freight Congestion And Transportation Performance Measures Using The National Performance Management Research Data Set (Npmrds), Yaxin Zhang

Dissertations and Theses

Traffic congestion is common in urban areas. It results in loss of productivity, increased risk of passenger safety, increased fuel consumption, environment pollution, etc. Improving performance measurement is a tool to improve traffic flow and capacity planning.

The main data source in this research is the National Performance Management Research Data Set (NPMRDS) for 2018. NPMRDS is a form of commercial GPS probe data, obtained from vehicles with on-board probe technologies. This dataset is licensed by the Federal Highway Administration and is made available to State Departments of Transportation (DOTs) and Metropolitan Planning Organizations (MPOs) for the purpose of federally …

Development Of An Injectable Methylcellulose Hydrogel System For Nucleus Pulposus Repair And Regeneration, Nada A. Haq-Siddiqi

Dissertations and Theses

Low back pain is the most common cause of disability in the world and is often caused by degeneration or injury of the intervertebral disc (IVD). The IVD is a complex, fibrocartilaginous tissue that allows for the wide range of spinal mobility. Disc degeneration is a progressive condition believed to begin in the central, gelatinous nucleus pulposus (NP) region of the tissue, for which there are few preventative therapies. Current therapeutic strategies include pain management and exercise, or surgical intervention such as spinal fusion, none of which address the underlying cause of degeneration. With an increasingly aging population, the socioeconomic …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Alternate Load Paths And Retrofits For Long-Span Truss Bridges Under Sudden Member Loss And Blast Loads, Huihui Li

Dissertations and Theses

In current bridge design practices, due to the existence of alternate load paths (ALPs), continued stability and progressive collapse-resistance of long-span bridges following the initialed loss of a critical member can be attributed to “redundancy”. However, “redundancy”, also indicated as the post member failure behavior of long-span bridges is not well understood and is not explicitly considered, especially for long-span truss bridges. As one of the most famous collapse events that took place recently, collapse of the I-35W truss bridge has demonstrated the vulnerabilities of long-span truss bridges, and their societal and economic consequences under the abnormal events, such as …