Engineering Commons^™

Approach To Problem Solving And Use Of Intuition By Engineering Technology Students, Meher R. Taleyarkhan, Anne M. Lucietto, Natalie L. F. Hobson, Therese M. Azevedo

Journal of Global Education and Research

Engineering technology students often forgo a methodical approach of solving or answering questions on assignments or exams in favor of an intuition-based approach, emphasizing educated guessing (Broberg et al., 2008). Faculty observations have noted these student solutions often provide explanations, usually sans calculations, to support answers the students believe to be reasonable when in reality deviated from the correct answer. An extensive study was developed to assess several distinctions between student intuition and use of cognition in problem solving, as related to a generalized student population. The study was comprised of a survey and interview. The survey utilized two instruments ...

Like You Search, Gipson Bachman

LMU/LLS Theses and Dissertations

As consumers continue to make their purchases solely online without visiting brick-and-mortar stores, they increasingly look for ways to “touch, feel and try on” products without actually doing so. We believe social media influencers provide a way to do this, with the influencers themselves acting as “stand-ins” for consumers in their place. Finding influencers that look like you in 2022 sounds like it would be easy, but it isn’t. Until now.

LIKE YOU aims to answer this gap in the market by creating a proprietary search engine that, through answering a few questions, recommends a list of influencers that ...

A Review On Nanomaterials And Nanohybrids Based Bio-Nanocomposites For Food Packaging, Kalpani Y. Perera, Amit K. Jaiswal, Swarna Jaiswal

Articles

With an increasing demand for a novel, eco-friendly, high-performance packaging material “bio-nanocomposites” has attracted great attention in recent years. The review article aims at to evaluating recent innovation in bio-nanocomposites for food packaging applications. The current trends and research over the last three years of the various bio-nanocomposites including inorganic, organic nanomaterials, and nanohybrids, which are suitable as food packaging materials due to their advanced properties such as high mechanical, thermal, barrier, antimicrobial, and antioxidant are described in detail. In addition, the legislation, migration studies, and SWOT analysis on bio-nanocomposite film have been discussed. It has been observed that the ...

Live Imaging Of Micro And Macro Wettability Variations Of Carbonate Oil Reservoirs For Enhanced Oil Recovery And Co/ Trapping/Storage, Anastasia Ivanova, A. Orekhov, S. Markovic, Stefan Iglauer, P. Grishin, A. Cheremisin

Research outputs 2022 to 2026

Carbonate hydrocarbon reservoirs are considered as potential candidates for chemically enhanced oil recovery and for CO² geological storage. However, investigation of one main controlling parameter—wettability—is usually performed by conventional integral methods at the core-scale. Moreover, literature reports show that wettability distribution may vary at the micro-scale due to the chemical heterogeneity of the reservoir and residing fluids. These differences may profoundly affect the derivation of other reservoir parameters such as relative permeability and capillary pressure, thus rendering subsequent simulations inaccurate. Here we developed an innovative approach by comparing the wettability distribution on carbonates at micro and macro-scale by ...

A Novel Microgrid Fault Detection And Classification Method Using Maximal Overlap Discrete Wavelet Packet Transform And An Augmented Lagrangian Particle Swarm Optimization-Support Vector Machine, Masoud Ahmadipour, Muhammad Murtadha Othman, Rui Bo, Zainal Salam, Hussein Mohammed Ridha, Kamrul Hasan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an intelligent method for fault detection and classification for a microgrid (MG) was proposed. The idea was based on the combination of three computational tools: signal processing using the maximal overlap discrete wavelet packet transform (MODWPT), parameter optimization by the augmented Lagrangian particle swarm optimization (ALPSO), and machine learning using the support vector machine (SVM). The MODWPT was applied to preprocess half cycle of the post-fault current samples measured at both ends of feeders. The wavelet coefficients derived from the MODWPT were statistically evaluated using the mean, standard deviation, energy, skewness, kurtosis, logarithmic energy entropy, max, min ...

Learning To Automate Follow-Up Question Generation Using Process Knowledge For Depression Triage On Reddit Posts, Shrey Gupta, Anmol Agarwal, Manas Gaur, Kaushik Roy, Vignesh Narayanan, Ponnurangam Kumaraguru, Amit Sheth

Publications

Conversational Agents (CAs) powered with deep language models (DLMs) have shown tremendous promise in the domain of mental health. Prominently, the CAs have been used to provide informational or therapeutic services (e.g., cognitive behavioral therapy) to patients. However, the utility of CAs to assist in mental health triaging has not been explored in the existing work as it requires a controlled generation of follow-up questions (FQs), which are often initiated and guided by the mental health professionals (MHPs) in clinical settings. In the context of `depression', our experiments show that DLMs coupled with process knowledge in a mental health ...

Preparation And Wear Properties Of High-Vanadium Alloy Composite Layer, Fangfang Wang, Liujie Xu, Shizhong Wei, Xi Wang, Chong Chen, Yucheng Zhou

Friction

A high-vanadium alloy composite layer was prepared on the surface of a carbon steel using cast composite technology, and the wear properties of the composite layer were investigated. The results showed that the microstructure of the composite layer was composed of primary vanadium carbides (VC), flake martensite, residual austenite, and fine VC. The hardness of the cast alloy layer was 63 HRC. The abrasive wear resistance and impact wear resistance were increased by 60% and 26%, respectively, compared with those of high-chromium cast iron. The excellent wear resistance of the cast alloy layer is attributed to the high-hardness primary vanadium ...

An Advanced Efficient Model For Adhesive Wear In Elastic–Plastic Spherical Contact, Haibo Zhang, Izhak Etsion

Friction

A finite element (FE) model combining submodel technique is presented for the adhesive wear in elastic–plastic spherical contact. It consists of a global model, showing the potential location of fracture under combined normal and tangential loading, and a refined mesh submodel covering only the region near the potential fracture. This allows to describe the morphology of wear particle more accurately than that in a previously developed model by the authors. A range of normal loading is studied to show its effect on the shape and volume of wear particles. Two main regimes of mild and severe wear (along with ...

Unlocking The Secrets Behind Liquid Superlubricity: A State-Of-The-Art Review On Phenomena And Mechanisms, Tianyi Han, Shuowen Zhang, Chenhui Zhang

Friction

Superlubricity, the state of ultralow friction between two sliding surfaces, has become a frontier subject in tribology. Here, a state-of-the-art review of the phenomena and mechanisms of liquid superlubricity are presented based on our ten-year research, to unlock the secrets behind liquid superlubricity, a major approach to achieve superlubricity. An overview of the discovery of liquid superlubricity materials is presented from five different categories, including water and acid-based solutions, hydrated materials, ionic liquids (ILs), two-dimensional (2D) materials as lubricant additives, and oil-based lubricants, to show the hydrodynamic and hydration contributions to liquid superlubricity. The review also discusses four methods to ...

Bio-Inspired Smart Surface To Achieve Controllable Locomotion Through Adjustable Anisotropic Friction, Zhongying Ji, Shiyu Qin, Shuanhong Ma, Xin Jia, Xiaolong Wang, Feng Zhou

Friction

Anisotropic friction generated by microstructured surfaces is crucial for performing functions such as directional locomotion and adhesion in biological systems. Hence, an epoxy-based shape memory polymer (SMP) incorporating Fe₃O₄ nanoparticles is used in this study to create a smart surface with oriented structures to mimic anisotropic friction and exploit human-developed controllable locomotion systems. Applying the specific properties of the epoxy-based SMP, fast switching friction can be achieved by adjusting the topography and stiffness of the microstructures on the surface. In addition, the photothermogenesis effect of Fe₃O₄ nanoparticles induces changes in the asymmetric topography and ...

Robust Scalable Reversible Strong Adhesion By Gecko-Inspired Composite Design, Xiaosong Li, Pengpeng Bai, Xinxin Li, Lvzhou Li, Yuanzhe Li, Hongyu Lu, Liran Ma, Yonggang Meng, Yu Tian

Friction

Bio-inspired reversible adhesion has significant potential in many fields requiring flexible grasping and manipulation, such as precision manufacturing, flexible electronics, and intelligent robotics. Despite extensive efforts for adhesive synthesis with a high adhesion strength at the interface, an effective strategy to actively tune the adhesion capacity between a strong attachment and an easy detachment spanning a wide range of scales has been lagged. Herein, we report a novel soft-hard-soft sandwiched composite design to achieve a stable, repeatable, and reversible strong adhesion with an easily scalable performance for a large area ranging from ~1.5 to 150 cm² and a ...

Role Of Capillary Adhesion In The Friction Peak During The Tacky Transition, Tianyan Gao, Jiaxin Ye, Kaisen Zhang, Xiaojun Liu, Yan Zhang, Kun Liu

Friction

The friction peak that occurs in tire–road sliding when the contact changes from wet to dry was previously attributed to capillary cohesion, van der Waals attraction, and surface roughness, but the detailed mechanisms have yet to be revealed. In this study, friction and static contact experiments were conducted using a custom-built in situ optical microtribometer, which allowed us to investigate the evolution of the friction, normal load, and contact area between a polydimethylsiloxane (PDMS) film and a silicon nitride ball during water volatilization. The friction coefficient increased by 100%, and the normal force dropped by 30% relative to those ...

Optimization Of Several Surface Treatment Processes For Alleviating Fretting Damage Of A Locking Pin, Jifan He, Zhenbing Cai, Yanping Ren, Jinfang Peng, Jianhua Liu, Minhao Zhu

Friction

The operational safety and reliability of a variable gauge train are affected by the anti-fretting wear performance of the locking mechanism. The main purpose of this study is to optimize the surface treatment process for a locking pin material under actual service conditions to alleviate fretting damage. Based on the two basic principles of surface strengthening and friction reduction, a substrate (AISI 4135 steel) surface was treated by laser quenching (LQ), plasma nitriding (PN), and bonded MoS₂ coating. Systematic fretting wear tests were conducted, and the wear behavior and damage mechanism of various treated surfaces were comprehensively investigated. The ...

Laser Pattern-Induced Unidirectional Lubricant Flow For Lubrication Track Replenishment, Chenglong Liu, Feng Guo, Patrick Wong, Xinming Li

Friction

Effective oil replenishment to the lubrication track of a running bearing is crucial to its sustainable operation. Reliable practical solutions are rare despite numerous theoretical studies were conducted in the last few decades. This paper proposes the use of surface effect, wettability gradient, to achieve the goal. This method is simple and can be nicely implemented using femtosecond laser ablation. A periodic comb-tooth-shaped pattern with anisotropic wetting capability is devised and its effect on the anisotropic spreading behaviour of an oil droplet is studied. Results show that the comb-tooth-shaped pattern enables the rearrangement of oil distribution, thereby escalating oil replenishment ...

Tribological Performance And Scuffing Behaviors Of Several Automobile Piston Rings Mating With Chrome-Plated Cylinder Liner, Zeyu Ma, Ruoxuan Huang, Xiaoshuai Yuan, Yan Shen, Jiujun Xu

Friction

The friction and wear properties, as well as the scuffing resistance, of different piston-ring coatings mating with a chrome-plated cylinder liner were investigated. Interrupted wear tests under the lubricant starvation condition were conducted to examine the wear behavior of Cr-diamond coating (GDC) and diamond-like coating (DLC). The results indicated that the DLC coating had outstanding tribological properties (small coefficient of friction and wear loss) at 150 °C, while the GDC coating exhibited better performance at an elevated temperature (240 °C). The DLC coating had a better scuffing resistance; no material adhesion occurred for 70 min under the unlubricated condition. The ...

Load Dependent Microstructural Evolution In An As-Cast 26% Cr High Chromium Cast Iron During Unlubricated Sliding, U. Pranav Nayak, Sebastian Suárez, Valentin Pesnel, Frank Mücklich, María Agustina Guitar

Friction

In the current study, an as-cast 26% Cr high chromium cast iron (HCCI) alloy was subjected to dry-sliding linear wear tests, under different loads. The loads were selected based on analytically computing the critical load (P_C) i.e., the load necessary to induce plastic deformation. The P_C was calculated to be 15 N and accordingly, a sub-critical load (5 N) and an over-critical load (20 N) were chosen. The influence of increasing the load during the wear test was investigated in terms of the matrix microstructural behaviour and its ability to support the surrounding carbides. The morphological aspects ...

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rockfalls and unstable slopes pose a serious threat to people and property along roads/highways in the southwestern mountainous regions of Saudi Arabia. In this study, the application of terrestrial light detection and ranging (LiDAR) technology was applied aiming to propose a strategy to analyze and accurately depict the detection of rockfall changes, calculation of rockfall volume, and evaluate rockfall hazards along the Habs Road, Jazan Region, Saudi Arabia. A series of temporal LiDAR scans were acquired at three selected sites. Our results show that these three sites have different degrees of hazard due to their geological differences. The mean ...

Effects Of Imu Sensor Location And Number On The Validity Of Vertical Acceleration Time-Series Data In Countermovement Jumping, Dianne Althouse

All Graduate Plan B and other Reports

Many devices are available for measuring the height of a CMJ. An inertial measurement unit (IMU) measures linear acceleration, orientation, and angular velocity. As an alternative to using IMU estimates of flight time, CMJ height could be estimated by integrating the IMU time-series signal for vertical acceleration to derive CMJ take-off velocity in order to track whole-body center of mass (WBCoM) movement, yet this approach would require valid IMU acceleration data. Thus, the purpose of this study was to quantify the effects of IMU sensor location and number on the validity of vertical acceleration estimation in CMJ. Thirty young adults ...

Submodularity And Local Search Approaches For Maximum Capture Problems Under Generalized Extreme Value Models, Tien Thanh Dam, Thuy Anh Ta, Tien Mai

Research Collection School Of Computing and Information Systems

We study the maximum capture problem in facility location under random utility models, i.e., the problem of seeking to locate new facilities in a competitive market such that the captured user demand is maximized, assuming that each customer chooses among all available facilities according to a random utility maximization model. We employ the generalized extreme value (GEV) family of discrete choice models and show that the objective function in this context is monotonic and submodular. This finding implies that a simple greedy heuristic can always guarantee a (1−1/e) approximation solution. We further develop a new algorithm combining ...

The Effects Of Host-Like Environmental Signals And Gene Expression On Capsule Growth In Cryptococcus Neoformans, Yu Min Jung

McKelvey School of Engineering Theses & Dissertations

Cryptococcus neoformans is a fungal pathogen that causes cryptococcosis, a disease that kills almost 200,000 people worldwide each year. A unique feature of this deadly yeast is its polysaccharide capsule, which is known to be associated with its virulence. Here, we systematically explore the effects of all possible combinations of 4 capsule-inducing signals on gene expression, cell size, and capsule size. These signals are medium (YPD, DMEM or RPMI), temperature (30°C or 37°C), CO₂ (room air or 5%), cAMP (0 mM or 20 mM), and pH buffer (HEPES/no HEPES). We explore the effects of exogenous ...