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Articles 6121 - 6150 of 27415

Full-Text Articles in Engineering

Lldpe Film Development Surface With Nucleating Agents To Reduce Fat Stains From Food Adherence On The Film Surface For Easy Rinsing Before Recycling, Nattapong Pinpru, Chiranicha Ninthap, Supang Sripraphot, Supharada Khaisaat Jan 2024

Lldpe Film Development Surface With Nucleating Agents To Reduce Fat Stains From Food Adherence On The Film Surface For Easy Rinsing Before Recycling, Nattapong Pinpru, Chiranicha Ninthap, Supang Sripraphot, Supharada Khaisaat

Journal of Metals, Materials and Minerals

The purpose of this research was to enhance the surface of linear low-density polyethylene (LLDPE) film by using single and hybrid nucleating agents to reduce fat stains from food adherence on the film surface for easy rinsing before recycling, consequently reducing energy consumption before recycling. The process begins with the preparation of a high-concentration masterbatch of LLDPE with nucleating agents and polyethylene glycol (PEG), followed by blown film and test analysis. The results showed that both single and hybrid nucleating agents resulted in substantial modifications in the surface characteristics of the film. The altered surface texture of the film makes …

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Fast Microwave Synthesis Of High-Silica Natural Soil Based Porous Geopolymer, Naritsara Toobpeng, Sirithan Jiemsirilers Jan 2024

Fast Microwave Synthesis Of High-Silica Natural Soil Based Porous Geopolymer, Naritsara Toobpeng, Sirithan Jiemsirilers

Journal of Metals, Materials and Minerals

This study describes a simple microwave process for fabricating porous geopolymer-polymer based Shirasu soil. The porous geopolymer samples were synthesized using sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution as alkaline solution in range of 0.5 M to 9 M. After mixing process, the geopolymer slurry was heated and stimulated geopolymerization reaction by different microwave powers at 200 W, 500 W and 700 W for 30 s, 60 s, 90 s and 120 s. The influence of NaOH concentration, microwave powers and heating times on the apparent bulk density, the water adsorption was focused. Results showed that the microwave powers …

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Investigating The High-Impact Deformation Behavior Of Induced-Nano Precipitation Hardened In718 Alloy, Harrison Okechukwu Onovo, Muideen Adebayo Bodude, David Ehigie Esezobor, Thaddeus Tochukwu Akano Jan 2024

Investigating The High-Impact Deformation Behavior Of Induced-Nano Precipitation Hardened In718 Alloy, Harrison Okechukwu Onovo, Muideen Adebayo Bodude, David Ehigie Esezobor, Thaddeus Tochukwu Akano

Journal of Metals, Materials and Minerals

Superalloys are the preferred materials for modern high-rotational complex components due to their exceptional ability to maintain critical properties such as strength, oxidation/corrosion resistance, even under extreme temperatures and dynamic impacts. This study investigates the dynamic impact response of nanoprecipitation-hardened 718 alloy (NPH-718 alloy) under various loading conditions. The wrought nickel-based NPH-718 alloy was transformed into a nanostructured state through a precise heat treatment process involving controlled cooling rates (28℃∙s‒1 to 30℃∙s‒1). A mechanical compression test, leading to failure, was employed to assess the alloy's ability to withstand dynamic impacts. The compressive dynamic behavior of the alloy at high strain …

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Atmospheric Hydrochloric And Nitric Acid Leaching Of A Limonite Ore From The Wolo Mine Area, Southeast Sulawesi, Indonesia, Sufriadin -, Malyanus Yepta, Irzal Nur, Purwanto -, Rizky Amalia, Ulva Ria Irfan, Djabal Nur Basir, Tsubasa Otake Jan 2024

Atmospheric Hydrochloric And Nitric Acid Leaching Of A Limonite Ore From The Wolo Mine Area, Southeast Sulawesi, Indonesia, Sufriadin -, Malyanus Yepta, Irzal Nur, Purwanto -, Rizky Amalia, Ulva Ria Irfan, Djabal Nur Basir, Tsubasa Otake

Journal of Metals, Materials and Minerals

The atmospheric acid leaching studies of a limonite ore sample from the Wolo mine area, Southeast Sulawesi, Indonesia, have been performed using hydrochloric acid (HCl) and nitric acid (HNO3). The objectives of these studies were to compare the leaching degree of metals (Ni, Co, Fe, and Al) and to analyze the dissolution behavior of minerals under different acid concentrations. Mineralogical characterization of the ore sample was conducted using optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction, whereas chemical composition was determined by X-ray fluorescence (XRF) spectrometry and atomic absorption spectroscopy (AAS), respectively. An atmospheric leaching test was done with …

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In Vitro And Vivo Biocompatibility And Degradability Of Low-Alloyed Mg-Zn-Ca-Mgo Composite As Bone Repair Biomaterials, Shuquan Zhang, Jiangtao Feng, Chaokun Tang, Ran Pang, Xinglong Zhang, Chenguang Li, Weihao Zhang, Fengxin Zhou, Feng Xue, Shaoyuan Lyu, Minfang Chen, Hao Wang Jan 2024

In Vitro And Vivo Biocompatibility And Degradability Of Low-Alloyed Mg-Zn-Ca-Mgo Composite As Bone Repair Biomaterials, Shuquan Zhang, Jiangtao Feng, Chaokun Tang, Ran Pang, Xinglong Zhang, Chenguang Li, Weihao Zhang, Fengxin Zhou, Feng Xue, Shaoyuan Lyu, Minfang Chen, Hao Wang

Journal of Metals, Materials and Minerals

Magnesium alloys have gained attention as biodegradable bone repair biomaterials. Unlike non-biodegradable materials like titanium and tantalum, biodegradable implants offer advantages in promoting bone healing and minimizing chronic inflammatory reactions. However, the impact of the implant's degradation on the osteogenic environment remains a concern. The Mg-Zn-Ca-MgO composite, being biocompatible and containing osteogenic ions, is a promising candidate. This study assesses the degradability and in vitro/in vivo biocompatibility of two Mg-Zn-Ca-MgO composites with varying degradation rates. The Mg-1Zn-0.2Ca-1.0MgO composite was prepared, and leaching solutions were created following standard protocols. MC3T3-E1 cell cultures were conducted to assess cell toxicity, alkaline phosphatase (ALP) …

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Virtual Reality & Pilot Training: Existing Technologies, Challenges & Opportunities, Tim Marron, Niall Dungan, Brian Mac Namee, Anna Donnla O'Hagan Jan 2024

Virtual Reality & Pilot Training: Existing Technologies, Challenges & Opportunities, Tim Marron, Niall Dungan, Brian Mac Namee, Anna Donnla O'Hagan

Journal of Aviation/Aerospace Education & Research

The introduction of virtual reality (VR) to flying training has recently gained much attention, with numerous VR companies, such as Loft Dynamics and VRpilot, looking to enhance the training process. Such a considerable change to how pilots are trained is a subject that warrants careful consideration. Examining the effect that VR has on learning in other areas gives us an idea of how VR can be suitably applied to flying training. Some of the benefits offered by VR include increased safety, decreased costs, and increased environmental sustainability. Nevertheless, some challenges ahead for developers to consider are negative transfer of learning, …

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Training Methods Research Opportunities For A Pilot Workforce In Transition: A Literature Review, James Birdsong, Kurt L. Reesman Jan 2024

Training Methods Research Opportunities For A Pilot Workforce In Transition: A Literature Review, James Birdsong, Kurt L. Reesman

Journal of Aviation/Aerospace Education & Research

Over the next 15 years, 50% of the U.S. commercial air carrier workforce will retire, making way for younger pilots from Generations Y and Z. This review identifies the emerging pilot workforce and training methods, including emerging technologies and learning methods, as well as research gaps.

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Interpersonal Skills In A Sociotechnical System: A Training Gap In Flight Decks, Kimberly Perkins, Sourojit Ghosh, Crystal Hall Jan 2024

Interpersonal Skills In A Sociotechnical System: A Training Gap In Flight Decks, Kimberly Perkins, Sourojit Ghosh, Crystal Hall

Journal of Aviation/Aerospace Education & Research

This research analyzed the perceptions of interpersonal skills on established aviation safety models, Crew Resource Management (CRM), and Threat and Error Management (TEM) using feedback from industry pilots. The flight deck is a sociotechnical system where much research has focused on the technical aspect, whereas we spotlight its socio aspect. The aviation industry must invest in training pilots on interpersonal skills to enhance safety through increased efficacy of safety models integrated throughout existing training programs. A 34-question survey was disseminated across both commercial and business aviation pilots (N=822). We explored three research questions regarding pilots’ perceived training on interpersonal skills …

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Assessing Past Airworthiness Directives And How Safety Management Systems May Benefit Aviation Product Design And Manufacturing, Damon Lercel, Manoj Patankar, Richard Steckel Jan 2024

Assessing Past Airworthiness Directives And How Safety Management Systems May Benefit Aviation Product Design And Manufacturing, Damon Lercel, Manoj Patankar, Richard Steckel

Journal of Aviation/Aerospace Education & Research

The European Union Aviation Safety Agency (EASA) continues to promulgate Safety Management Systems (SMS) across aviation organizations when it recently issued SMS requirements for EASA certificated Part 145 maintenance, repair and overhaul (MRO) organizations and Part 21 Design & Manufacturing (D&M) organizations. Currently, the Federal Aviation Administration (FAA) has no such rule in place for these U.S.-based organizations, which may challenge those doing business in countries where EASA policies apply. Given that a majority of the United States’ D&M and MRO population is made up of smaller organizations, it is likely a U.S. SMS regulation will require justification of the …

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History’S Slowest Digital Transformation: The Long Road To Flight Data Monitoring, Michael Ott Jan 2024

History’S Slowest Digital Transformation: The Long Road To Flight Data Monitoring, Michael Ott

Journal of Aviation/Aerospace Education & Research

Flight data monitoring (FDM) began in the flight test community in 1939 and entered the airline industry in 1974. In the 48 years since, however, very few operators have chosen to adopt this practice, which has shown clear safety benefits where it has found acceptance. While technical issues have created some obstacles, cultural issues have proven the greatest hindrance to wider FDM adoption. These cultural issues originated in the traits associated with pilots’ personalities, especially distrust of the regulators and operators who would administer flight data analysis programs (FDAP) that used FDM information. U.S. regulators have relied on voluntary adoption, …

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Application Of Density Altitude Climatology To General Aviation Impacts, Thomas A. Guinn, Daniel J. Halperin, Sarah Strazzo Jan 2024

Application Of Density Altitude Climatology To General Aviation Impacts, Thomas A. Guinn, Daniel J. Halperin, Sarah Strazzo

Journal of Aviation/Aerospace Education & Research

Density altitude (DA) plays a key role in flight safety because it helps pilots anticipate poor aircraft performance when temperatures are warmer than standard. In this study, a 30-year climatology of DA for the conterminous United States was created using the fifth-generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis of the global climate (ERA5) dataset was applied to four separate DA-based, aircraft-performance, rules-of-thumb for general aviation (GA) flight. The goal was to demonstrate a technique to create educational visualization tools showing the variation of operational flight impacts with both month and location. Four such parameters were chosen to show …

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Integrated Organizational Machine Learning For Aviation Flight Data, Michael J. Pritchard, Austin T. Walden, Paul J. Thomas Jan 2024

Integrated Organizational Machine Learning For Aviation Flight Data, Michael J. Pritchard, Austin T. Walden, Paul J. Thomas

Journal of Aviation/Aerospace Education & Research

Increased availability of data and computing power has allowed organizations to apply machine learning techniques to various fleet monitoring activities. Additionally, our ability to acquire aircraft data has increased due to the miniaturization of small form factor computing machines. Aircraft data collection processes contain many data features in the form of multivariate time series (continuous, discrete, categorical, etc.) which can be used to train machine learning models. Yet, three major challenges still face many flight organizations: 1) integration and automation of data collection frameworks, 2) data cleanup and preparation, and 3) developing an embedded machine learning framework. Data cleanup and …

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Review Of Vr Technical Specification Requirements For A Procedural Training Task, Stephanie G. Fussell Jan 2024

Review Of Vr Technical Specification Requirements For A Procedural Training Task, Stephanie G. Fussell

Journal of Aviation/Aerospace Education & Research

Many aviation education and training programs are expanding their learning materials to include virtual learning environments (VLEs) that utilize virtual reality (VR) technology. While developing training materials and the VLE, an understanding of technical specification requirements is needed to inform stakeholders who need to choose a headset for a given training scenario. As part of a larger initiative to compare the usability of multiple VR headsets for implementation into procedural training, a review of the extant literature was conducted to identify technical specifications of VR head-mounted displays, followed by a pilot test of a head-mounted display (HMD) comparison methodology that …

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High-Flying Results: A Case Study In A Pilot Development Mentor Program, Catherine G. Cordova, Barron Parsons-Daisley, Emma Fox Captain Jan 2024

High-Flying Results: A Case Study In A Pilot Development Mentor Program, Catherine G. Cordova, Barron Parsons-Daisley, Emma Fox Captain

Journal of Aviation/Aerospace Education & Research

Consistently considered one of the world’s most stressful occupations, the job of an airline pilot requires increasingly specific skills and responsibilities, especially amidst the global pandemic (Cullen, et al., 2020; Sew, et al., 2022). Given the severity and implications of their decisions and actions, airline pilots must continuously undergo training and practices to ensure proper procedure. In 2020, the Federal Aviation Administration (FAA) augmented qualifications by enacting Pilot Professional Development requirements (85 FR 10923), including mentoring for newly hired pilots in command (PIC’s). In complement with 85 FR 10923, CFR 121-N ensures “techniques for reinforcing the highest standards of technical …

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Diversity, Equity, And Inclusion: Trends In Representation Of Women Professionals In The Aviation Industry, Caroline K. Marete, Cheng Wang Jan 2024

Diversity, Equity, And Inclusion: Trends In Representation Of Women Professionals In The Aviation Industry, Caroline K. Marete, Cheng Wang

Journal of Aviation/Aerospace Education & Research

Diversity, equity, and inclusion (DEI) stands as an integral component of any successful organization. Historically, society has overlooked and underplayed DEI matters, resulting in the underrepresentation of minority groups, including women and people of color. In the past decade, underrepresentation of women and other minority groups in the aviation workforce has received attention and raised concerns among industry stakeholders. To gain insight into the status of women in aviation, the authors analyzed the participation of females in aviation professions between 2016 and 2021. Data used in this study were retrieved from the 2023 U.S. Civil Airmen Statistics published by the …

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Computational Cognitive Modeling Of Pilot Performance In Pre-Flight And Take-Off Procedures, Rongbing Xu, Shi Cao, Suzanne K. Kearns, Ewa Niechwiej-Szwedo, Elizabeth Irving Jan 2024

Computational Cognitive Modeling Of Pilot Performance In Pre-Flight And Take-Off Procedures, Rongbing Xu, Shi Cao, Suzanne K. Kearns, Ewa Niechwiej-Szwedo, Elizabeth Irving

Journal of Aviation/Aerospace Education & Research

While the current practice of pilot training relies on flight instructors’ subjective assessment, computational cognitive modeling may be used to support future objective assessment and diagnosis of pilot performance. We built two models in a cognitive architecture to simulate pilot flight performance during pre-flight and take-off tasks. Modeling results were compared with human results collected from the same tasks using X-Plane 11 flight simulator. The models were able to capture human pilot performance and workload results from both tasks with good levels of fitness (percentage errors ranging from 0.8% to 13.2%). This work demonstrated the capability and advantage of this …

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Machine Learning - Hail Awareness Spatial Analysis Toolkit (Hasat), Haoruo Fu, Joseph P. Hupy, Chien-Tsung Lu, Zhenglei Ji Jan 2024

Machine Learning - Hail Awareness Spatial Analysis Toolkit (Hasat), Haoruo Fu, Joseph P. Hupy, Chien-Tsung Lu, Zhenglei Ji

Journal of Aviation/Aerospace Education & Research

The National Airspace System (NAS) is a sophisticated network of air traffic control, navigation, and communication systems that play a critical role in ensuring the safe and efficient flow of air traffic across the United States. However, the occurrence of severe weather conditions, particularly hailstorms, poses a significant threat to flight safety within the NAS. To mitigate the risks associated with hail, aviation organizations have implemented a range of safety measures. This study utilized Esri’s ArcGIS as a mapping software to conduct a geospatial analysis of the impact of severe weather, particularly hail, on the NAS. The Hail Awareness Spatial …

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An Exploratory Single-Case Study Unveiling The Promise Of Artificial Intelligence In Aviation Education, Jorge L. D. Albelo, Stacey Mcintire Jan 2024

An Exploratory Single-Case Study Unveiling The Promise Of Artificial Intelligence In Aviation Education, Jorge L. D. Albelo, Stacey Mcintire

Journal of Aviation/Aerospace Education & Research

Higher education institutions continuously seek ways to improve teaching methods and enhance student learning experiences by leveraging emerging technologies in the classroom. One such technology is ChatGPT, an artificial intelligence (AI) application. The integration of this AI technology in aviation education has the potential to transform teaching and learning experiences. This study aims to investigate the acceptance and integration of ChatGPT in aviation education and understand the benefits and challenges associated with integrating such technology. The study employs a mixed methods approach, combining qualitative focus group discussions with aviation professors and a quantitative survey administered to students. The study included …

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A New Trajectory In Uav Safety: Leveraging Reinforcement Learning For Distance Maintenance Under Wind Variations, Xiaolin Xu, Jeffrey Sun Jan 2024

A New Trajectory In Uav Safety: Leveraging Reinforcement Learning For Distance Maintenance Under Wind Variations, Xiaolin Xu, Jeffrey Sun

Journal of Aviation/Aerospace Education & Research

In the field of aviation, safety is a critical cornerstone, and the operation of Unmanned Aerial Vehicle (UAV) systems is deeply connected with this principle. A thorough analysis and rigorous simulation and testing of aircraft systems are essential to avoid severe safety hazards. This paper delves into the safety issue in UAV operations, specifically regarding maintaining minimum safety distances under fluctuating wind conditions. The study introduces a novel solution based on a Deep Deterministic Policy Gradient (DDPG) model, a reinforcement learning method. The DDPG model was trained using a simulated environment created through the Gazebo simulator, with values for wind …

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Human-Ai Teams In Aviation: Considerations From Human Factors And Team Science, Jenna Korentsides, Joseph R. Keebler, Crystal M. Fausett, Sabina M. Patel, Elizabeth H. Lazzara Jan 2024

Human-Ai Teams In Aviation: Considerations From Human Factors And Team Science, Jenna Korentsides, Joseph R. Keebler, Crystal M. Fausett, Sabina M. Patel, Elizabeth H. Lazzara

Journal of Aviation/Aerospace Education & Research

Artificial Intelligence (AI) has transformed the way human-computer interaction (HCI) teams can collaborate and coordinate in various domains, including aviation and crew resource management (CRM). AI's transformative capabilities enhance teamwork, efficiency, and safety, particularly in risk management. AI's ability to process vast amounts of data and provide real-time insights enables informed decision-making and automation of repetitive tasks in aviation. By combining the strengths of AI and humans, outlined in our modified version of the ‘HABA-MABA’ framework, a dynamic teamwork relationship emerges, provided roles are successfully allocated. AI systems are able to act as intelligent assistants, offering timely recommendations, fostering effective …

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Low-Resource Automatic Speech Recognition Domain Adaptation – A Case-Study In Aviation Maintenance, Nadine Amin, Tracy L. Yother, Julia Rayz Jan 2024

Low-Resource Automatic Speech Recognition Domain Adaptation – A Case-Study In Aviation Maintenance, Nadine Amin, Tracy L. Yother, Julia Rayz

Journal of Aviation/Aerospace Education & Research

With timeliness and efficiency being critical in the aviation maintenance industry, the need has been growing for smart technological solutions that optimize and streamline the different underlying tasks (Bergkvist & Sabbagh, 2021). One such task is the technical documentation of the performed maintenance operations (Chandola et al., 2022). Instead of manual documentation, voice tools that transcribe spoken logbook entries allow technicians to document their work right away in a hands-free and time efficient manner. However, an accurate automatic speech recognition (ASR) model requires large training corpora (Siyaev & Jo, 2021a), which are lacking in the domain of aviation maintenance. In …

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An Enhanced Deep Autoencoder For Flight Delay Prediction, Desmond B. Bisandu, Dan Andrei Soviani-Sitoiu, Irene Moulitsas Jan 2024

An Enhanced Deep Autoencoder For Flight Delay Prediction, Desmond B. Bisandu, Dan Andrei Soviani-Sitoiu, Irene Moulitsas

Journal of Aviation/Aerospace Education & Research

Accurate and timely flight delay prediction cannot be overemphasized because of the ever-increasing demand for air travel and its importance in deploying intelligent transportation systems. Nonetheless, there has not been a universal solution to the problem, as more intelligent flight decision systems are required for the aviation industry's future growth. Existing flight delay classification and prediction approaches are mainly shallow traffic models and do not satisfy many applications in the real world. Our motivation to rethink the deep architecture model for predicting flight delays emanates from the problem. In this research, we proposed a technique that modified stacked autoencoder architecture …

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Real-Time Detection Of Sea Turtles Using Uav And Neural Networks On Edge Devices, Jose A. Gonzalez Nunez, Jose G. Gonzalez Nunez, Mustafa I. Akbas, Patrick Currier, Nickolas D. Macchiarella Jan 2024

Real-Time Detection Of Sea Turtles Using Uav And Neural Networks On Edge Devices, Jose A. Gonzalez Nunez, Jose G. Gonzalez Nunez, Mustafa I. Akbas, Patrick Currier, Nickolas D. Macchiarella

Journal of Aviation/Aerospace Education & Research

Sea turtle populations continue to diminish around the globe for various reasons. Therefore, the need for innovative solutions to monitor sea turtles has been increasing. This research paper focuses on an innovative application of artificial intelligence (AI) and machine learning (ML) together with unmanned aerial vehicles (UAV) to improve sea turtle conservation efforts. We outline the design, implementation, and evaluation of a system that deploys UAVs equipped with high-resolution cameras, coupled with a purpose-built neural network to recognize, classify, and monitor sea turtles. This project thus serves as a platform for understanding the wider applicability and limitations of this technology …

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User Experience, Motivation And Self-Efficacy Comparisons Between Virtual Reality And Conventional Pc-Based Flight Simulation Training, Tianxin Zhang, Christina Frederick, Andrew Dattel, Elizabeth Blickensderfer, Barbara Chaparro Jan 2024

User Experience, Motivation And Self-Efficacy Comparisons Between Virtual Reality And Conventional Pc-Based Flight Simulation Training, Tianxin Zhang, Christina Frederick, Andrew Dattel, Elizabeth Blickensderfer, Barbara Chaparro

Journal of Aviation/Aerospace Education & Research

The current project investigated the effect of utilizing Virtual Reality (VR) technologies for flight training by comparing user experience, motivation, and self-efficacy when using conventional desktop flight simulation versus VR flight simulation. This research employed a quasi-transfer of training experiment with 48 participants. Findings showed that VR flight simulation could provide a better user experience and generate a higher level of training motivation than traditional training technologies, while maintaining trainees’ perceptions of self-efficacy. This work contributed positive evidence that VR flight simulation has great potential to be an effective means of flight training and provided a foundation for future research …

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Air Jet Assisted Combustion Of Oil Diffusion Flames: Effects Of Injection Location And Excess Air Factor, Moustafa Ahmed Gamaleldin, Neama Youssef Ramadan, Ahmed Mohamed Abdulnaim, Ahmed Abdelnasser Adam, Ahmed Abdulrazik Emara, Hany Ahmed Moneib Jan 2024

Air Jet Assisted Combustion Of Oil Diffusion Flames: Effects Of Injection Location And Excess Air Factor, Moustafa Ahmed Gamaleldin, Neama Youssef Ramadan, Ahmed Mohamed Abdulnaim, Ahmed Abdelnasser Adam, Ahmed Abdulrazik Emara, Hany Ahmed Moneib

Trends in advanced sciences and technology

This study investigates a novel methodology for a coaxial disc stabilized burner with a central jet oil spray. It introduces multiple air injection jets within the burner gun's exit section, promoting earlier fuel vaporization and rapid fuel-air mixture formation in the premixing zone. This directly contributes to improved overall combustion efficiency and reduced exhaust emissions. The focus lies on identifying the optimal location for the air injection jets (fixed load, constant jet momentum, and angle) within the exiting premixing zone of the burner gun. In-flame measurements are conducted inside a cylindrical combustor at different air injection locations and varying excess …

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Energy And Exergy Analysis Of Multi-Stage Axial Flow Compressor: Degree Of Reaction, Inlet Temperature, And Pressure Ratio Impacts, Mohamed Abdelaal, Rafea Mohamed Abd El-Maksoud, Nazih Noaman Bayomi Jan 2024

Energy And Exergy Analysis Of Multi-Stage Axial Flow Compressor: Degree Of Reaction, Inlet Temperature, And Pressure Ratio Impacts, Mohamed Abdelaal, Rafea Mohamed Abd El-Maksoud, Nazih Noaman Bayomi

Trends in advanced sciences and technology

This paper presents a comprehensive energy and exergy analysis of a multistage axial compressor, specifically examining a 12-stage model to assess the impact of varying inlet temperatures, degrees of reaction, and pressure ratios. This study contributes to the ongoing efforts to optimize compressor technology for better performance and reduced energy consumption, emphasizing the importance of parameter selection in achieving desired operational outcomes. In the current research, the performance of the axial compressor was studied from an energy and exergy point of view while changing the parameters previously mentioned in detail as stages and rotors due to the lack of previous …

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Impact Of Glottis Area On Airflow Dynamics In The Human Trachea Using A Simplified Stenosis Pipe Model, Amany M. Kamal, Momtaz Sedrak, Abouelmagd Abdelsamie Jan 2024

Impact Of Glottis Area On Airflow Dynamics In The Human Trachea Using A Simplified Stenosis Pipe Model, Amany M. Kamal, Momtaz Sedrak, Abouelmagd Abdelsamie

Trends in advanced sciences and technology

A complex transitional flow is produced in the larynx during air inhalation process, pivotal for fundamental comprehension and medical advancements in treatment methodologies. This study delves into the influence of the glottis region utilizing a simplified stenosis pipe geometry, examining two distinct cases: (1) the axisymmetric case and (2) the eccentric case. Reynolds-averaged Navier–Stokes equations with shear stress transport (SST) 𝑘 − 𝜔 turbulence model with intermittency transition activated with steady, Newtonian, and incompressible airflow have been used. The analysis underscores the significant impact of the eccentricity on the velocity by increasing 0.6% comparing with axisymmetric case, also particularly affecting …

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Dynamic Analysis And Experimental Verification Of Flexible Unbalance Rotor Supported By Two Identical Journal Bearings, Omar Ahmed, Hussein Sayed, T.A. El-Sayed Jan 2024

Dynamic Analysis And Experimental Verification Of Flexible Unbalance Rotor Supported By Two Identical Journal Bearings, Omar Ahmed, Hussein Sayed, T.A. El-Sayed

Trends in advanced sciences and technology

Abstract BACKGROUND: Analyzing the vibrations for rotor-bearing systems is a critical issue in the field of rotor dynamics. It is crucial to identify rotary machine vibrations, behaviors, and stability conditions. The main causes of vibration in rotating machinery are unbalanced masses, misalignment, mechanical looseness, shaft cracks, and other defects. METHODS: This paper investigates the experimental verification of a theoretical model, using a steel shaft with a disc set at the midpoint, supported by two symmetric fluid film bearings. The study examines the effect of unbalance on the dynamic behavior of the rotor and its vibration characteristics. The experimental investigation involved …

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Laboratory Characteristics, Performance Evaluation, And Agency Cost Analysis Of Cold-Recycled Asphalt Mixtures, Marwa B. Elaskary, Ahmed M. Awed, Alaa R. Gabr, Sherif M. El-Badawy Jan 2024

Laboratory Characteristics, Performance Evaluation, And Agency Cost Analysis Of Cold-Recycled Asphalt Mixtures, Marwa B. Elaskary, Ahmed M. Awed, Alaa R. Gabr, Sherif M. El-Badawy

Mansoura Engineering Journal

This technical study offers a comprehensive investigation into the utilization of Cold Recycled Asphalt Mixtures (CRAMs) with varying proportions of Reclaimed Asphalt Pavement (RAP) in the context of pavement maintenance applications. The study encompasses a multi-faceted analysis, encompassing laboratory mix design requirements, mix performance evaluations, and a thorough assessment of economic benefits, with the overarching goal of promoting the sustainable adoption of CRAMs in pavement maintenance. To achieve the objectives of the research, five ratios of RAP to virgin aggregates (VA) of (0%:100%), (25%:75%), (50%:50%), (75%:25%), and (100%: 0%). The research encompasses a wide array of laboratory tests and investigations …

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Influence Of Macro-Synthetic Fibers On The Flexural Behavior Of High Strength Concrete Beams Reinforced With Gfrp Bars, Maryam M. Koura, Ahmed M. Tahwia, Mohamed H. Matthana Jan 2024

Influence Of Macro-Synthetic Fibers On The Flexural Behavior Of High Strength Concrete Beams Reinforced With Gfrp Bars, Maryam M. Koura, Ahmed M. Tahwia, Mohamed H. Matthana

Mansoura Engineering Journal

Rusting of steel reinforcement in marine environments causes the overall destruction of reinforced concrete constructions; steel rebars in concrete members have been replaced with fiber-reinforced polymer (FRP) bars in recent years. To enhance the shear behavior of glass (GFRP) bars reinforced concrete (RC), macro-synthetic polyolefin (PO) fiber was added. These materials have a low modulus of elasticity, a high tensile strength, and a linear stress-strain response to full failure. This study investigates the effect of macro synthetic structural fibers on the post-cracking and deformability properties of high strength concrete reinforced with FRP bars without transverse reinforcement. Eight full-scale RC beams …

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