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2021

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Articles 4321 - 4350 of 9983

Full-Text Articles in Engineering

Three-Dimensional Laser-Assisted Printing Of Structures From Nanoparticles, Heng Pan, Chinmoy Podder, Wan Shou, Xiaowei Yu Jun 2021

Three-Dimensional Laser-Assisted Printing Of Structures From Nanoparticles, Heng Pan, Chinmoy Podder, Wan Shou, Xiaowei Yu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A method for manufacturing a component comprising bombarding nanoparticles in a dispersion with a laser to transform the ligand and cause the nanoparticles to drop out of the dispersion and deposit onto a substrate; and bombarding additional nanoparticles in the dispersion with the laser to transform the ligand and cause the nanoparticles to drop out of the dispersion and deposit onto the nanoparticles previously deposited out of the dispersion.


Fatigue And Its Management In The Aviation Industry, With Special Reference To Pilots, Rajee Olaganathan, Timothy B. Holt, Jackie Luedtke, Brent D. Bowen Jun 2021

Fatigue And Its Management In The Aviation Industry, With Special Reference To Pilots, Rajee Olaganathan, Timothy B. Holt, Jackie Luedtke, Brent D. Bowen

Journal of Aviation Technology and Engineering

Abstract Fatigue is a significant contributing factor that reduces human ability and leads to accidents and threatens the safety of aircraft and human lives. Approximately 70% of fatal accidents that occur in commercial aviation operations are due to human factors. More specifically, crew fatigue contributes to nearly 15 to 20% of the accidents (Akerstedt, 2000). These accidents and incidents are associated with pilot fatigue because of the long duty periods, disruption of circadian rhythms, and inadequate sleep that are common among both commercial and military pilots. Though fatigue is seen in all the disciplines associated with the aviation industry, this …


Martha: Offline Streaming Media For Cameroonian Refugees, Sarah Ahmed, Marco Marenzi, Leila Scola Jun 2021

Martha: Offline Streaming Media For Cameroonian Refugees, Sarah Ahmed, Marco Marenzi, Leila Scola

Computer Science and Engineering Senior Theses

MARTHA is a mobile application intended to deliver educational content to refugees from Cameroon currently residing in Nigeria. Refugees were forced to flee after advocating for educational freedom, so education is of utmost importance to those residing in these refugee camps. Parents want their children to benefit from learning general educational content, as well as vocational content which is important for social mobility. Our application will display files that can be followed at the users’ pace. While the project entails two phases, the final goal is to have a Raspberry Pi act as a server and local database, allowing local …


Detection Methods And Clinical Applications Of Circulating Tumor Cells In Breast Cancer, Hongyi Zhang, Xiaoyan Lin, Yuan Huang, Minghong Wang, Chunmei Cen, Shasha Tang, Marcia R. Dique, Lu Cai, Manuel A. Luis, Jillian Smollar, Yuan Wan, Fengfeng Cai Jun 2021

Detection Methods And Clinical Applications Of Circulating Tumor Cells In Breast Cancer, Hongyi Zhang, Xiaoyan Lin, Yuan Huang, Minghong Wang, Chunmei Cen, Shasha Tang, Marcia R. Dique, Lu Cai, Manuel A. Luis, Jillian Smollar, Yuan Wan, Fengfeng Cai

Publications and Research

Circulating Tumor Cells (CTCs) are cancer cells that split away from the primary tumor and appear in the circulatory system as singular units or clusters, which was first reported by Dr. Thomas Ashworth in 1869. CTCs migrate and implantation occurs at a new site, in a process commonly known as tumor metastasis. In the case of breast cancer, the tumor cells often migrate into locations such as the lungs, brain, and bones, even during the early stages, and this is a notable characteristic of breast cancer. Survival rates have increased significantly over the past few decades because of progress made …


Investigations Into Size And Surface Control Of Silicon Nanocrystals For Improved Optical Properties, James Donald Barnes Jun 2021

Investigations Into Size And Surface Control Of Silicon Nanocrystals For Improved Optical Properties, James Donald Barnes

Dissertations and Theses

The discovery of visible photoluminescence (PL) from nanocrystalline porous silicon in 1990 led to extensive research into the mechanisms of the emergent properties, and optimization of these properties, for use in applications. The widespread use of silicon nanoparticles (Si NPs) in commercial applications is currently limited by three main factors: 1) poor radiative recombination efficiency of the interband transition, 2) instability of the interband photoluminescence, and 3) a lack of scalable methods for producing Si NPs that are both highly crystalline and size monodisperse.

To address these limitations, this dissertation correlates changes in the photoluminescence properties of hydrogen passivated silicon …


Incorporating Conditional Ss-Mean Based Equity Metric In Coverage Based Facility Location Problems, Rohan Sirupa Jun 2021

Incorporating Conditional Ss-Mean Based Equity Metric In Coverage Based Facility Location Problems, Rohan Sirupa

Dissertations and Theses

A classical maximum coverage facility location problem (MCLP) tries to maximize the coverage by serving all possible demands within the specified coverage radius. Depending on the applications, several families of MCLP variants have been developed - each with its unique set of additional constraints. One specific application is locating Emergency medical service (EMS) units. EMS units such as ambulances or drones with emergency supplies are located using models such as the maximum expected survival location problem (MEXSLP). However, a classical MEXSLP model tends to locate EMS units near densely populated regions, resulting in increased response times for lowly populated regions. …


The Impact Of Human Factors And Maintenance Documentation On Aviation Safety: An Analysis Of 15 Years Of Accident Data Through The Pear Framework, Flavio A. C. Mendonca, Natalie Zimmermann Jun 2021

The Impact Of Human Factors And Maintenance Documentation On Aviation Safety: An Analysis Of 15 Years Of Accident Data Through The Pear Framework, Flavio A. C. Mendonca, Natalie Zimmermann

Publications

Regardless of the type of maintenance performed on aircraft, instructions are to be used to provide the aviation technicians completing the maintenance activities with guidance on, and an outline of, the maintenance items to be performed and completed. However, the use of instructions does not guarantee the correct and proper completion of the maintenance activities as the instructions may be erroneous and/or maintenance personnel can misunderstand, misinterpret, or improperly follow the procedures outlined. Resulting maintenance errors can potentially result in aircraft accidents, as illustrated by Air Midwest Flight 5481. With the purpose of understanding how human factors associated with written …


Research Productivity Of Wadia Institute Of Himalayan Geology, Devendra Singh Rawat, Kunwar Singh, Madan Singh, Avadhesh Kumar Patel, Ayush Kumar Patel Jun 2021

Research Productivity Of Wadia Institute Of Himalayan Geology, Devendra Singh Rawat, Kunwar Singh, Madan Singh, Avadhesh Kumar Patel, Ayush Kumar Patel

Library Philosophy and Practice (e-journal)

Bibliometric analysis was used to assess the research productivity of the Wadia Institute of Himalayan Geological (WIHG) during 1991-2020. Data was collected from the Scopus database, and VOSviewer software used for visualization. The study focused on various bibliometrics parameters like year-wise research growth, Authors productivity, Growth rates measures (AGR, RGR, Dt), Collaboration measures (DC and CC), subject-wise distributions, most prolific authors, highly collaborative institutions, most cited documents, top funding agency, types of documents, etc. The results showed that the maximum number of documents, 93 (7.21%), were published in 2017. India and the United States of America contributed the highest numbers …


Recent Trends In Software-Defined Networking: A Bibliometric Review, Jones Jefferson, Harikrishnan R Jun 2021

Recent Trends In Software-Defined Networking: A Bibliometric Review, Jones Jefferson, Harikrishnan R

Library Philosophy and Practice (e-journal)

Software-Defined Networking is referred to as the next big thing in the field of networking. Legacy networks contain various components such as switches, routers, etc. with a variety of complex protocols. A network administrator is responsible for configuring all these various components. Apart from complex network management, network security is also a persistent issue in the field of networking. SDN promises simplicity in network management while also dramatically improving the security of networks. This paper gives an analysis of the current trends in in SDN as well as Security challenges with SDN. A bibliometric review on SDN has also been …


Effect Of Synergistic Aging On Bauxite Residue Dust Reduction Performance Via The Application Of Colloids, An Orthogonal Design‐Based Study, Xuhan Ding, Guang Xu, Dengfei Wang, Zhenmin Luo, Tao Wang Jun 2021

Effect Of Synergistic Aging On Bauxite Residue Dust Reduction Performance Via The Application Of Colloids, An Orthogonal Design‐Based Study, Xuhan Ding, Guang Xu, Dengfei Wang, Zhenmin Luo, Tao Wang

Mining Engineering Faculty Research & Creative Works

The application of polymer colloids is a promising approach for bauxite residue dust pollution control. However, due to the existence of synergistic aging, the efficiency of colloid dynamic viscosity to predict the dust control performance of bauxite residue is unclear. Previous studies were also rarely performed under synergistic aging conditions. Thus, this paper investigates the relationship between colloids' viscosity and dust control performance under synergistic aging modes. Results illustrated that the binary colloid achieved better dust control performance than unitary colloid for their higher viscosity and penetration resistance. For both unitary and binary colloid, higher viscosity results in better crust …


Bibliometric Analysis On Artificial Compressibility Method Based Cfd Simulations, Bhavna Hemraj Joshi Miss, Chandrakant R. Sonawane Dr, Priyambada Bada Praharaj Mrs, Anand Kumar Pandey Dr Jun 2021

Bibliometric Analysis On Artificial Compressibility Method Based Cfd Simulations, Bhavna Hemraj Joshi Miss, Chandrakant R. Sonawane Dr, Priyambada Bada Praharaj Mrs, Anand Kumar Pandey Dr

Library Philosophy and Practice (e-journal)

This bibliometric analysis in this paper aims to study the quantitative progress done in the artificial compressibility (AC) method-based CFD simulation and analyze its potential in solving incompressible flow simulations in computational fluid dynamics smoothly. The sector of CFD is enhancing more and more maturely due to advancements in computing architecture, numerical methods, and simulation tools. There have been various attempts to solve the pressure-velocity coupling issue in the Navier-Stokes equation. The artificial compressibility method (ACM), as opposed to pressure-correction methods, solves the incompressible equation in a non-segregated manner. With the introduction of the ACM, the system of the equation …


Splitting The Scatter: Distinguishing Marine Organisms From Oceanographic Structures Using Acoustic Monitoring, Zhen Lu, Daisuke Hasegawa, Takahiro Tanaka, David M. Spencer, Yuji Okazaki, Takeshi Okunishi Jun 2021

Splitting The Scatter: Distinguishing Marine Organisms From Oceanographic Structures Using Acoustic Monitoring, Zhen Lu, Daisuke Hasegawa, Takahiro Tanaka, David M. Spencer, Yuji Okazaki, Takeshi Okunishi

Journal of Marine Science and Technology–Taiwan

In the northwest Pacific Ocean, off the Sanriku coast of Japan, convergence between the Tsugaru Warm Current (TWC) and the cold Oyashio Current (OC) results in the formation of highly dynamic oceanographic features that promote high biodiversity and generate hotspots for a range of commercially important fisheries. However, their effects on local biodiversity over much smaller spatiotemporal scales ( < 1 km) remains unclear. With the development of acoustic technology in recent years, echo-sounders are increasingly being used to conduct high-precision fishery resource assessments and detect small-scale variability in the oceanic thermohaline structure. In this study, we conducted a simultaneous hydrographic and dual-frequency echo-sounder survey to discriminate oceanographic features and marine organisms in the TWC-OC confluence zone. Echograms of acoustic backscatter measured at 38 kHz detected similar oceanographic features that were obtained from our hydrographic survey observations, but these features were less pronounced in the 120 kHz echograms. The dynamic oceanographic structure in the TWC-OC zone returned a large amount of backscatter, making it difficult to identify marine organisms from the scatter. The frequency differences of volume backscattering strength (SV) were, however, able to distinguish oceanographic structures from zooplankton detections. Outcomes from this study highlight the difficulty of distinguishing between hydrographic and biological detections in dynamic oceanographic environments. Further research into the acoustic frequency characteristics of heterogeneous hydrographic features will help better understand how species distributions are affected, so that the acoustic method can be used to provide more accurate estimates of species abundance.


Fine-Scale Vertical Movements And Behavior Of Immature Skipjack Tuna (Katsuwonus Pelamis) Off Eastern Taiwan, Wei-Chuan Chiang, Takayuki Matsumoto, Shian-Jhong Lin, Qi-Xuan Chang, Michael K. Musyl, Yuan-Shing Ho, Fumio Ohta Jun 2021

Fine-Scale Vertical Movements And Behavior Of Immature Skipjack Tuna (Katsuwonus Pelamis) Off Eastern Taiwan, Wei-Chuan Chiang, Takayuki Matsumoto, Shian-Jhong Lin, Qi-Xuan Chang, Michael K. Musyl, Yuan-Shing Ho, Fumio Ohta

Journal of Marine Science and Technology–Taiwan

Skipjack tuna are globally distributed in tropical and temperate seas but little is known about their fine-scale diving patterns and how fish size and (or) maturity influences patterns off eastern Taiwan. A total of 211 immature skipjack (36 e 47 FL cm) in the study were caught by trolling near subsurface fish aggregating devices (FADs) near Green Island (southeastern Taiwan) and were tagged with Lotek LAT-2910 archival tags. The low rate of recovery (2.4%) suggests a high post-release mortality but this low rate could also be consistent with large population sizes, dispersal, tag loss or uncooperative fishers. Five individuals were …


Evaluating The Fish Aggregation Effect Of Wind Turbine Facilities By Using Scientific Echo Sounder In Nanlong Wind Farm Area, Western Taiwan, Ting-Chieh Huang, Hsueh-Jung Lu, Jia-Rong Lin, Shih-Hsuan Sun, Kou-Wei Yen, Jing-Yi Chen Jun 2021

Evaluating The Fish Aggregation Effect Of Wind Turbine Facilities By Using Scientific Echo Sounder In Nanlong Wind Farm Area, Western Taiwan, Ting-Chieh Huang, Hsueh-Jung Lu, Jia-Rong Lin, Shih-Hsuan Sun, Kou-Wei Yen, Jing-Yi Chen

Journal of Marine Science and Technology–Taiwan

During the stages of construction and operation of the wind power facilities, fishery and fishery resources in the wind farm areas will certainly be changed greatly. One of the major concern is the aggregation effect of wind turbines facility. We use scientific echo sounder together with scuba diving to survey fish aggregations in the wind farm areas. In order to obtain echoes very near the facility, we use tilt beam angle instead of traditional vertical one. Variation of target strength varies while using tilted beam angle were discussed both by ex-situ and in-situ experiment. In ex-situ experiment, we measured TS …


Funds Of Knowledge As Pre-College Experiences That Promote Minoritized Students’ Interest, Self-Efficacy Beliefs, And Choice Of Majoring In Engineering, Dina Verdín, Jessica M. Smith, Juan Lucena Jun 2021

Funds Of Knowledge As Pre-College Experiences That Promote Minoritized Students’ Interest, Self-Efficacy Beliefs, And Choice Of Majoring In Engineering, Dina Verdín, Jessica M. Smith, Juan Lucena

Journal of Pre-College Engineering Education Research (J-PEER)

Pre-college experiences both inside and outside of the classroom inform students’ interest in science, technology, engineering, and mathematics (STEM)-related activities, help them evaluate their knowledge and skills in various tasks, and shape their perceptions of themselves as individuals who can participate in STEM. Yet little empirical research examines the valuable pre-college knowledge, practices, and skills that minoritized students acquire through their home experiences and how they can support students’ transition into an engineering pathway. This study addresses this gap by investigating how students’ funds of knowledge support their interest in engineering, self-efficacy beliefs, and certainty of pursuing an engineering major. …


The Production Of Epistemic Culture And Agency During A First-Grade Engineering Design Unit In An Urban Emergent School, Heidi B. Carlone, Alison K. Mercier, Salem R. Metzger Jun 2021

The Production Of Epistemic Culture And Agency During A First-Grade Engineering Design Unit In An Urban Emergent School, Heidi B. Carlone, Alison K. Mercier, Salem R. Metzger

Journal of Pre-College Engineering Education Research (J-PEER)

Primary school practices are often bound by traditions that perpetuate compliance and skills-based, decontextualized, rote memorization activities. These histories of practice, prevalent in schools serving mostly Black and Brown children, make it inordinately difficult for students to author themselves as knowledge builders (i.e., with epistemic agency), which is a form of injustice. Engineering is a potentially fertile context to support the creation of epistemic culture, whereby young students’ assets are recognized, named, and leveraged as they create and shape the group’s disciplinary knowledge. The authors investigated this potential. The primary research question was: How do first-grade students in an urban …


Equitable Pre-College Engineering Education: Teaching With Racism In Mind, James Holly Jr Jun 2021

Equitable Pre-College Engineering Education: Teaching With Racism In Mind, James Holly Jr

Journal of Pre-College Engineering Education Research (J-PEER)

Engineering educators must consider how the cultural backgrounds of students coincide (or diverge) with the epistemological and ontological formation of an engineer. Hence, this work is presented as an exhortation to engineering educators, particularly in a pre-college context, to critically evaluate how race-conscious pedagogies can be exerted in this field. In this autoethnographic study, I convey my attempt to teach engineering with explicit consideration of the sociopolitical context of the Black male youth I taught. As a Black male, I have an insider perspective into the realities that must be navigated to succeed in a racialized society, where Black males …


Site Fidelity And Return Trips Of Visually And Olfactorily Inhibited Black Rockfish (Sebastes Schlegelii) Individuals Tracked By Acoustic Telemetry, Mitsuki Kuroda, Yoshinori Tatsu, Yuya Ueda, Hokuto Shirakawa, Kenji Minami, Kazushi Miyashita, Makoto Tomiyasu Jun 2021

Site Fidelity And Return Trips Of Visually And Olfactorily Inhibited Black Rockfish (Sebastes Schlegelii) Individuals Tracked By Acoustic Telemetry, Mitsuki Kuroda, Yoshinori Tatsu, Yuya Ueda, Hokuto Shirakawa, Kenji Minami, Kazushi Miyashita, Makoto Tomiyasu

Journal of Marine Science and Technology–Taiwan

For fish of the genus Sebastes, which have strong site fidelity, understanding the characteristics of their return trips and how their sensory cues influence behavior will be useful for conservation and resource management. Here, we conducted a behavioral tracking study for the black rockfish Sebastes schlegelii using acoustic telemetry and sensory inhibition. We compared aspects of the return process for individuals in a control group (CNT), and fish in blind (BLD) and olfactory inhibition (OLF) conditions. Nine individuals were released 850 m from the fishing site, and all of them returned. However, the time taken to complete the return varied, …


Geospatial And Acoustic Application In An Artificial Reef Site Of South Korea, Myounghee Kang, Rina Fajaryanti, Kyounghoon Lee, Eun-A Yoon, Woo-Seok Oh, Eunbi Min, Young-Jae Shin, Yong-Suk Choi, Byung-Ho Yi, Hui Zhang, Doojin Hwang Jun 2021

Geospatial And Acoustic Application In An Artificial Reef Site Of South Korea, Myounghee Kang, Rina Fajaryanti, Kyounghoon Lee, Eun-A Yoon, Woo-Seok Oh, Eunbi Min, Young-Jae Shin, Yong-Suk Choi, Byung-Ho Yi, Hui Zhang, Doojin Hwang

Journal of Marine Science and Technology–Taiwan

Artificial reefs are important since they provide additional habitat leading to increasing abundance and biomass of marine biota. In a Bukchon artificial reef, Jeju Island, South Korea, environment data, artificial reef properties, and acoustic data in four seasons were integrated to visualize and examine their connections using a geographic information system (GIS). As a result, regarding the spatial and temporal distributions of fishes, January had the lowest Nautical Area Scattering Coefficient (NASC, m2/nm2) and June had the highest NASC, and relatively high NASC was observed from 5 to 30 m deep throughout seasons. The influential circle (effective distance from reef) …


Milkguard: Predictive Modeling And Mobile App Development For Affordable, Usable Breast Milk Diagnostic, Beau Hsia, Emma Mccurry Jun 2021

Milkguard: Predictive Modeling And Mobile App Development For Affordable, Usable Breast Milk Diagnostic, Beau Hsia, Emma Mccurry

Bioengineering Senior Theses

Breast milk is considered the gold standard of infant nutrition, but some infants around the world lack access to it due to maternal health complications or other considerations. Human breast milk banks do exist to try to alleviate this problem, but most are underfunded and have high operational costs, making it difficult for some infants to obtain safe, reliable donated breast milk.

Existing methods of testing breast milk are expensive, so the MilkGuard project was conceptualized in 2017 as a fast, economical, and highly usable bacterial contamination detection system. Prior to this year, previous MilkGuard teams had developed a system …


A Method For Monitoring Operating Equipment Effectiveness With The Internet Of Things And Big Data, Carl D. Hays Iii Jun 2021

A Method For Monitoring Operating Equipment Effectiveness With The Internet Of Things And Big Data, Carl D. Hays Iii

Master's Theses

The purpose of this paper was to use the Overall Equipment Effectiveness productivity formula in plant manufacturing and convert it to measuring productivity for forklifts. Productivity for a forklift was defined as being available and picking up and moving containers at port locations in Seattle and Alaska. This research uses performance measures in plant manufacturing and applies them to mobile equipment in order to establish the most effective means of analyzing reliability and productivity. Using the Internet of Things to collect data on fifteen forklift trucks in three different locations, this data was then analyzed over a six-month period to …


Modeling Action Potential Propagation During Hypertrophic Cardiomyopathy Through A Three-Dimensional Computational Model, Julia Elizabeth Kelley Jun 2021

Modeling Action Potential Propagation During Hypertrophic Cardiomyopathy Through A Three-Dimensional Computational Model, Julia Elizabeth Kelley

Master's Theses

Hypertrophic cardiomyopathy (HCM) is the most common monogenic disorder and the leading cause of sudden arrhythmic death in children and young adults. It is typically asymptomatic and first manifests itself during cardiac arrest, making it a challenge to diagnose in advance. Computational models can explore and reveal underlying molecular mechanisms in cardiac electrophysiology by allowing researchers to alter various parameters such as tissue size or ionic current amplitudes. The goal of this thesis is to develop a computational model in MATLAB and to determine if this model can accurately indicate cases of hypertrophic cardiomyopathy. This goal is achieved by combining …


A Half Yearly Newsletter -Department Of Aeronautical And Automobile Engineering, Mohammad Zuber Dr Jun 2021

A Half Yearly Newsletter -Department Of Aeronautical And Automobile Engineering, Mohammad Zuber Dr

Faculty work

No abstract provided.


Electromagnetic Wave Propagation For Industry And Biomedical Applications, Fred Lacy Jun 2021

Electromagnetic Wave Propagation For Industry And Biomedical Applications, Fred Lacy

Faculty Publications

Superconductors have a wide array of applications, such as medical imaging, supercomputing, and electric power transmission, but superconducting materials only operate at very cold temperatures. Thus, the quest to engineer room temperature superconductors is currently a hot topic of research. To accomplish this mission, it is important to have a complete understanding of the material properties that are being used to create these superconductors. Understanding the atomic and electromagnetic properties of the prospective materials will provide tremendous insight into the best choice for the materials. Therefore, a theoretical model that incorporates electromagnetic field theory and quantum mechanics principles is utilized …


Music For Me, Zachary Graber, William Henrion Jun 2021

Music For Me, Zachary Graber, William Henrion

Computer Science and Engineering Senior Theses

Music For Me is an online web application that enables users to compose improvised music alongside an AI. Users have an array of understandable, easy to use yet powerful options available to them. While previous AI-collaborative music improvisation tools exist, they are either limited in scope, with minimal structure and user customization or completely overwhelming with a large amount of provided options so as to be inaccessible except to those dedicated to learning the program. This web application provides an intersection between these two extremes, providing a pick-up and play model that allows for a rich improvisational experience while still …


Non-Ribosomal In Vivo Protein Ligation, Sarah Desautel, Kenneth Joseph, Victorino Miguel Francisco Jun 2021

Non-Ribosomal In Vivo Protein Ligation, Sarah Desautel, Kenneth Joseph, Victorino Miguel Francisco

Bioengineering Senior Theses

Protein ligation is a process integral to many biomedical applications, however the current industry standard, expressed protein ligation (EPL), is highly error prone and time-and-cost inefficient. Our team sought to improve this integral process by proving the efficacy of a new method of protein ligation using the transpeptidase Sortase A. Sortase A is known to efficiently bind two peptide fragments so long as they are attached to LPXTG motifs, which signal and activate the enzyme’s ligation abilities. Previous studies affirm Sortase A’s binding ability and efficacy in in vitro situations, however none have yet confirmed its abilities in vivo. Operating …


Warming Enabled Upslope Advance In Western Us Forest Fires, Mohammad Reza Alizadeh, John T. Abatzoglou, Charles H. Luce, Jan F. Adamowski, Arvin Farid, Mojtaba Sadegh Jun 2021

Warming Enabled Upslope Advance In Western Us Forest Fires, Mohammad Reza Alizadeh, John T. Abatzoglou, Charles H. Luce, Jan F. Adamowski, Arvin Farid, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Increases in burned area and large fire occurrence are widely documented over the western United States over the past half century. Here, we focus on the elevational distribution of forest fires in mountainous ecoregions of the western United States and show the largest increase rates in burned area above 2,500 m during 1984 to 2017. Furthermore, we show that high-elevation fires advanced upslope with a median cumulative change of 252 m (−107 to 656 m; 95% CI) in 34 y across studied ecoregions. We also document a strong interannual relationship between high-elevation fires and warm season vapor pressure deficit (VPD). …


Minimizing Leakage In Thin Walled Structures Printed Through Selective Laser Melting, Andrew Spencer Yap Jun 2021

Minimizing Leakage In Thin Walled Structures Printed Through Selective Laser Melting, Andrew Spencer Yap

Master's Theses

In this project, the scan strategy of selective laser melting (SLM) for thin walled structures was investigated by changing laser parameters and tool path. Producing thin walled structures is difficult due to defects such as warpage and porosity. A layer on the SLM 125 consists of hatch volume, fill contours, and borders, however, for thin walls, hatch volume can become unavailable, resulting in a solely border/fill contour laser tool path.

Three central composite designs (CCD) were created to optimize the laser parameters of borders to minimize leakage rate and porosity. The two factors changed were border laser power and scanning …


Anthropogenic Drought: Definition, Challenges, And Opportunities, Mojtaba Sadegh Jun 2021

Anthropogenic Drought: Definition, Challenges, And Opportunities, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions …


The Thermal Conductivity Of Polar Firn, Simon Oster Jun 2021

The Thermal Conductivity Of Polar Firn, Simon Oster

ENGS 88 Honors Thesis (AB Students)

A custom device is designed, validated, and used to make the first reported direct measurements of the effective thermal conductivity of polar firn. The firn cores spanned depths from 8 to 47 m from an undisturbed site near the South Pole in Antarctica. The thermal conductivity varies with depth, with values ranging from 0.617 to 1.018 W/mK, and the associated thermal diffusivities range from 20.95 to 25.68 m2/a. Density and porosity contribute to the variation in thermal conductivity but cannot be used to completely prescribe the conductivity. Initial analyses indicate that firn microstructure relates to conductivity through Euler-Poincaré …