Digital Commons Network^™

Investigation Of Insertion Loss In Inkjet-Printed Coplanar Waveguide Based On Drying Temperature, Jun Ho Yu, Sung Min Sim, Jin Woo Choi, Sang Ho Lee, Jung Mu Kim

Michigan Tech Publications

In this study, we propose an optimized inkjet printing process to improve the insertion loss of inkjet-printed coplanar waveguide (CPW) transmission lines. The process involves varying the drying temperature and adjusting the number of printing steps to investigate their effects on the electrical characteristics of the printed CPW. The relationships between surface roughness, surface cavities, morphological changes, and insertion loss are studied by conducting atomic force microscopy analysis and by examining the insertion loss up to 3 GHz. The printed CPW that underwent low-temperature drying after the first printing and high-temperature drying after the second printing before sintering showed improved …

Historical Context In Mathematics Education: Improving Student Engagement And Achievement, Colette Chilton-Carr

Electronic Theses and Dissertations 2020 - Present

There are many informational gaps in contemporary mathematics education. Students see the mathematical topics they are being taught as facts and procedures unrelated to each other or to themselves as mathematicians. Many ancient developments in the realm of mathematics are still relevant today, showcasing the needs that motivated their longstanding evolution. By including the stories behind the formulas in mathematics classrooms, students from diverse backgrounds can feel seen and connected to their education. The inclusion of the holistic background of mathematics cannot be nurtured in the classroom without buy-in on the parts of both students and instructors, as well as …

Reducing Emergency Department To Medical Icu Boarding Times: Implementing A Standardized Escalation Protocol At A Large Medical Center Hospital, Taylor A. Robbins-Ethridge

Doctor of Nursing Practice Final Project Abstract

Prolonged emergency department (ED) boarding of critically ill patients awaiting transfer to the medical intensive care unit (MICU) delays access to definitive care and is associated with increased mortality and longer hospital stays. This quality improvement project aimed to reduce ED boarding times for MICU patients by implementing the Bed Ready in 30: Just Say Yes escalation protocol. The Plan–Do–Study–Act (PDSA) framework guided the implementation of a structured escalation process to standardize nurse-to-nurse communication once a MICU bed was marked as ready in the electronic health record. A pre–post observational study was used to evaluate the intervention using electronic health …

Optimizing Zeolite Catalysts For Efficient Ldpe Plastic Waste Pyrolysis, Hilda Porawati, Mazwan Mazwan, Sukadi Sukadi

Journal of Mechanical Engineering Science and Technology (JMEST)

The problem of plastic waste, particularly from low-density polyethylene (LDPE) plastic bags, poses a significant challenge in environmental management due to its non-biodegradable nature and widespread use in daily life. This study evaluates the influence of catalyst types on the characteristics and energy efficiency of liquid fuel products produced from LDPE waste pyrolysis. The three treatments compared were no catalysts, natural zeolite catalyst, and synthetic zeolite catalysts, each subjected to three different temperature variations: 250°C, 300°C, and 350°C. The observed parameters in this study were volume, product mass, cetane index, density, sulfur content, viscosity, flash point, calorific value, and energy …

One-Way Thermal-Fluid-Solid Coupling Analysis Of Helicopter Tail Reducer With Spiral Bevel Gear, Dongping Sheng, Zhongyuan Ma, Chenqi Zhou, Haidong Feng, Hun Guo, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

This research focuses on investigating the thermal-fluid-solid coupling behavior within spiral bevel gears to enhance the bearing capacity and extend the operational service life of the gear reducer located in the helicopter tail gearbox. The study commences by constructing detailed, parametrically defined threedimensional digital models. These models accurately represent the critical components: the spiral bevel gear itself, the surrounding gearbox housing, and the supporting gear shaft, based directly on the specifications of an actual helicopter tail reducer assembly. Subsequently, the analysis proceeds with a one-way, steadystate thermal-solid coupling simulation performed on the established model assembly. This critical simulation phase aims …

Thermophysical, Rheological And Wear Resistance Of Canola Oil Biolubricant With Calcium Carbonate Additive Nanoparticle As Coolant In Cnc Machining, Alfandi Jaelani, Poppy Puspitasari, Diki Dwi Pramono, Alief Muhammad, Muhammad Kozin, Muhammad Kashif

Journal of Mechanical Engineering Science and Technology (JMEST)

Vegetable oil-based cutting fluids are of great importance in supporting green and sustainable manufacturing. This research introduces a new groundbreaking vegetable lubricant formulated with canola oil as the base material, coupled with CaCO3 nanoparticles synthesized from scallop shell waste and used as a cutting fluid in the AISI 1045 CNC machining process steel sprayed with minimum quantity lubrication (MQL). This investigation delves into the thermophysical, rheological, and wear resistance of the developed bio-lubricant. The results of this analysis show density value increased in the canola + CaCO3 0.15% sample by 3.28% of the pure canola sample, as did the viscosity …

Improvement Of Thermal Energy Storage Performance In Al-Al2o3 Composites Through Additions Of Copper: Evaluation Of Microstructure And Thermal Properties, Muhammad Hasan Basri, Ramang Magga, Muhammad Syaiful Fadly, Zikri Arifansyah Djaba, Muhammad Iqbal Ibrahim, Hidayat Hidayat, Yandi Yandi

Journal of Mechanical Engineering Science and Technology (JMEST)

The study aims to evaluate the influence of adding copper aluminum–alumina composite (Al–Al₂O₃) against characteristic thermal properties through metallurgical powder. Three variations of the composition of weight copper were used, namely 5%, 10%, and 15%, with aluminum as the matrix and alumina as the reinforcement. Thermal test covering analysis of thermal conductivity, specific heat, and microstructure characterization using SEM-EDX. The results show that adding Cu increases thermal conductivity significantly, with the highest mark achieved in the 15% Cu composite (6.47 W/m.°C). However, the increase in Cu content above 10% causes the agglomeration of particles and enhancements in porosity, which harms …

Numerical Investigation Of Ethanol-Enriched Diesel And Biodiesel Fuels In A Diesel Engine, Annisa Bhikuning, Hezron Elyakim Potto, Sandi Apriandi Setiawan, Jamal F. Jati

Journal of Mechanical Engineering Science and Technology (JMEST)

This study explores the effects of ethanol blending on the performance and emissions of a compression ignition (CI) engine using both diesel and biodiesel as base fuels. Motivated by increasing environmental concerns regarding pollutant emissions from conventional diesel engines, ethanol was introduced as an oxygenated additive to improve combustion characteristics and reduce the formation of harmful exhaust emissions. Ethanol’s high oxygen content promotes more complete combustion, potentially lowering carbon-based emissions such as carbon monoxide (CO), particulate matter (PM), and unburned hydrocarbons. In this study, performance and emission parameters were simulated using Diesel-RK software at various engine speeds of 1500, 2000, …

The Effect Of Preheater On Heat And Mass Transfer Efficiency Using Rotating Drum Roaster, Melisa Surya Andini, Retno Wulandari, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Indonesia is the third-largest coffee producer globally, facing challenges including rising raw material costs, increased energy consumption, and unpredictable weather conditions. One potential solution is optimizing energy efficiency during roasting. This study investigates the effect of preheating on time and energy efficiency in heat and mass transfer by utilizing waste heat to preheat green Robusta coffee beans. The experiment was conducted on a laboratory scale using a rotating drum roaster with a double-layer drum made of stainless steel and clay, at 200 °C under atmospheric pressure. Two treatments were applied: roasting with a preheater and without, each repeated three times …

Numerical Analysis Of The Effect Of Vortex Generator On The Aerodynamic Performance Of Naca 6412 Airfoils Using Large Eddy Simulation, Dedet Hermawan Setiabudi, Joan Bayuaji Nugroho, Eli Kumolosari, Lazuardy Rahendra Pinandhita, Okto Dinaryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Aerodynamic performance of an airfoil is significantly affected by flow separation, especially at high angles of attack. One common strategy to control flow separation is adding a triangular vortex generator (VG), which creates small vortices that help keep the airflow attached. The present study investigated the impact of triangular vortex generators on a NACA 6412 airfoil using Computational Fluid Dynamics (CFD) method. Large Eddy Simulation (LES) was applied due to its ability to show the vortices more clearly than other methods. It can also accurately capture the flow separation. To obtain the lift, drag, and lift-to-drag ratio (CL/CD) data, four …

Surface Modification Of Local Natural Fibers Via Alkali Treatment For Improved Mechanical And Molecular Properties Of Bamboo Fiber, Pineapple Leaf Fiber, And Sisal Fiber, Jibril Maulana, Muhammad Ilman Nur Sasongko, Dewi Izzatus Tsamroh, Muchammad Yafis, Syekhan Maulana

Journal of Mechanical Engineering Science and Technology (JMEST)

A major development in materials science toward reinforcement materials in biopolymer composites has been caused by a worldwide trend toward sustainable manufacturing and the rise of the circular economy. However, their mechanical properties can often be affected by their hydrophilic properties, lack of surface compatibility, and their presence of molecular bonding, such as lignin and hemicellulose. Alkaline surface modification has been widely reported as an effective technique to increase structural stability and fibermatrix adhesion. This study evaluated the effects of alkalizing three types of local natural fibers—bamboo fiber (BF), pineapple leaf fiber (PALF), and sisal (SF)—with sodium hydroxide (NaOH) at …

Full Factorial Design Of Carbon Content And Heating Temperature On Height Reduction In Bonnell Springs, Yurida Ekawati, Cendana Anggun Sasmitha, Mochamad Syamsul Ma’Arif

Journal of Mechanical Engineering Science and Technology (JMEST)

The durability of Bonnell springs, which are widely used in the manufacture of spring beds, is often compromised by height reduction during use, which negatively impacts product comfort and quality. This study aims to minimize spring height reduction by investigating the effects of heating temperature and carbon content in the spring steel. A full factorial experimental design was applied using two factors: heating temperature (250°C, 260°C, and 270°C) and carbon content (0.72%, 0.73%, and 0.74%). Nine treatment combinations were tested, with five replicates each, and the height reduction values were measured after 100 compression cycles. The data were analyzed using …

Young Adults And Early-Onset Psychosis: A Grounded Theory Study Of Experiences Of Identity Development, Katherine Hayden-Lewis, Deborah Rubel

The Qualitative Report

While identity development is a crucial task for young individuals ages 15-25, current research inadequately centralizes identity development in the context of first-time psychosis related to schizophrenia spectrum disorders. This study addresses the knowledge gap by exploring the grand research question, “How does a young person experience their identity development after the first episode of psychosis?”. Constructivist grounded theory methods influenced by critical frameworks were used to collect and analyze data with seven young adults engaged in first episode psychosis programs. Participants were young adults, between the ages of 19-24, that at the time of the study were enrolled in …

Potential Mechanisms Of Influence Between Spiritual Practices And Cognitive Health: A Systematic Review And Conceptual Model, Katherine Carroll Britt, Hayoung Oh, Augustine Cassis Obeng Boateng, Sherry Morgan, Sato Ashida, Corey Nagel, Roland J Thorpe, Harold G Koenig

Staff and Researcher Publications

Background/Objectives: This systematic review summarizes the evidence regarding potential mechanisms underlying the relationship between spiritual practices and cognitive health in adults. The review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist.

Methods: An extensive search of six electronic databases (i.e., PubMed, PsycINFO, Embase, Sociological Abstracts, ATLA, CINAHL) was conducted using keywords related to spiritual practices, religious activities, and cognitive health from 1 January 2000 to December 2025. The quality of the included studies was assessed using the Mixed Methods Appraisal tool aligned with the study design.

Results: A total of …

Jhtdb-Wind: A Web-Accessible Large-Eddy Simulation Database Of A Wind Farm With Virtual Sensor Querying, Xiaowei Zhu, Shuolin Xiao, Ghanesh Narasimhan, Luia A. Martinez-Tossas, Michael Schnaubelt, Gerard Lemson, Hanxun Yao, Alexander S. Szalay, Dennice F. Gayme, Charles Meneveau

Mechanical and Materials Engineering Faculty Publications and Presentations

This paper introduces JHTDB-wind (https://turbulence.idies.jhu.edu/datasets/windfarms), a publicly accessible database containing large-eddy simulation (LES) data from wind farms. Building on the framework of the Johns Hopkins Turbulence Database (JHTDB), which hosts direct numerical and some large-eddy simulation datasets of canonical turbulent flows, JHTDB-wind stores the full space-time (4D) history of the flow and provides users the ability to access and query the data via a web-based virtual sensor interface. The initial dataset comprises LES results from a large wind farm with 6 X 10 turbines, modeled using a filtered actuator line method, under conventionally neutral atmospheric conditions. This data comprises one …

Teachers’ Experiences With Physical Or Verbal Aggression In The Aftermath Of Covid-19, Juana M. Lang, Lucinda A. Hines, Karen Johnson

The Qualitative Report

This hermeneutical phenomenology study explored teachers’ lived experiences facing verbal or physical aggression from students after schools reopened post-COVID-19. Grounded in Bandura’s Social Learning Theory, Heider’s Attribution Theory, and Lazarus and Folkman’s Transactional Stress Theory, the study addressed the research question: What were teachers’ lived experiences with verbal or physical aggression from students after the first wave of COVID-19? Purposive and snowball sampling strategies were used in the study. The sample included four teachers (two middle schools and two high schools) from the Southeastern U.S. Data were collected through open-ended iterative interviews and analyzed thematically. Findings revealed four themes: teachers …

Physics Teachers' Perceptions About Diagnostic Assessment Of Students' Physics Misconception: A Phenomenological Study, Mutmainna Mutmainna, Edi Istiyono, Haryanto Haryanto, Heri Retnawati, Caly Setiawan

The Qualitative Report

Physics learning needs to be designed by teachers to minimize misconceptions. Different diagnostic tools have been developed and used by researchers to identify student misconceptions. However, each tool has advantages and disadvantages. Therefore, teachers play a crucial role, including their understanding of misconceptions and their ability to select the most effective tools according to their purpose. This study sought to uncover the experiences of eight physics teachers through phenomenological studies. Physics teachers involved in this research had diversity based on the period of experience teaching physics, geographical area, and education level. A virtual semi-structured interview (40 to 60 minutes) for …

Navigating The Storm: A Qualitative Metaphor-Based Analysis Of Resilience And Identity Reconstruction Among Displaced Professionals, Erhan Atay, Serkan Bayraktaroglu, Leo Johannesberg

The Qualitative Report

Building on previous management scholarship, this paper explains how Conceptual Metaphor Theory (CMT) and metaphorical expressions inform organizational resilience and leadership communication in employee support strategies. It tries to capture the interplay between personal sensemaking and collective adaptation. The study aims to provide practitioners with hands-on insights into developing inclusion, resilience, and identity reconstruction in organizational and societal contexts of disruption. The analysis identifies three critical metaphorical themes: resilience, which is likened to "climbing a mountain;" isolation, which is likened to being "trapped in a bubble;" and identity reconstruction, which is likened to "picking up the shattered pieces of a …

Navigating The Ethical Landscape: A Field Reflection On The Dynamics Of Informed Consent In Qualitative Research, Khim Raj Subedi, Peshal Khanal

The Qualitative Report

Our paper analyses the practical dimensions of obtaining informed consent in qualitative research, drawing on the reflective insight from fieldwork conducted as part of a study on the professional identity of primary (elementary) teachers in community schools in Nepal. Our study builds on and extends the understanding of informed consent as a legal and ethical requirement (Kadam, 2017) while considering the complexities of fieldwork. Drawing on interactions with six teachers and using the first author's detailed fieldnotes and reflexive memos, our study explores the challenges researchers face in securing consent during qualitative interviews. We argue that the consent-seeking process should …

Reflections On Researching Second-Generation Migrant Youths Amidst Covid-19 And Beyond: Challenges And Lessons For Future Researchers, Betty Chiyangwa

The Qualitative Report

The COVID-19 pandemic highlighted the need for researchers to adapt to innovative methodologies in qualitative research. I reflect on my doctoral experiences, examining the challenges I faced and lessons I learned during data collection amidst the COVID-19 pandemic and beyond. I explore the hurdles faced, mitigation measures adopted, and lessons for future researchers, using a reflective qualitative design that integrates my personal narrative and thematic analysis. The analysis included a systematic coding process, underpinned by critical narrative inquiry, reflections, observations and an analysis of my field notes. Six hurdles emerged during the data analysis process amidst COVID-19: (1) experiences of …

Association Between Cholecystectomy And Colorectal Cancer: Results From The National Health And Nutrition Examination Survey (Nhanes) 2017–2023 And Mendelian Randomization Analyses, Shunchen Zhou, Bosen Zhao, Jiaying Qu, Xingyu Gao, Xiaolin Wang, Chunhui Yang, Qiangsong Tong, Liduan Zheng

Faculty, Staff and Students Publications

Background: Cholecystectomy is widely used to treat gallbladder disease, but its link to colorectal cancer (CRC) remains controversial. This study aimed to assess the association between cholecystectomy and CRC by combining cross-sectional analysis with Mendelian randomization (MR).

Methods: We analyzed 12,490 adults from the National Health and Nutrition Examination Survey (NHANES) 2017-2023 for the association between cholecystectomy and CRC. Weighted logistic regression models with progressive adjustments were applied: Model 1 was unadjusted, Model 2 accounted for sociodemographic factors, while Model 3 was further controlled for lifestyle, diet, and comorbidities. Subgroup and sensitivity analyses were conducted to evaluate the results' robustness. …

Application Of The Surgical Apgar Score To Predict Intensive Care Unit Admission And Post-Operative Outcomes In Cesarean Hysterectomy For Placenta Accreta Spectrum, Emily Root, Jacqueline Curbelo, Patrick Ramsey, Jessian L Munoz

Faculty, Staff and Students Publications

Background and Objective: Placenta Accreta Spectrum (PAS) encompasses a continuum of abnormal placentation conditions associated with significant maternal and fetal morbidity. Management of PAS requires coordinated cesarean hysterectomy. Associated morbidities include blood transfusion, coagulopathy, and intensive care unit (ICU) admission. Accurate prediction of ICU admission allows for enhanced multidisciplinary management, coordination of care and utilization of resources. Scoring systems exist in other surgical specialties that can predict the likelihood of ICU admission, but these have not been applied to an obstetric population. The SAS is a 10-point scale that has been validated for the prediction of ICU-level care requirements within …

Ai-Driven Innovations For Sustainable Healthcare Architecture In Developing Countries And Remote Areas: Enhancing Efficiency Through Futuristic Design, Esraa Elazab, Ahmed Eltawil

HBRC Journal

Access to healthcare in developing countries and remote areas remains a critical challenge due to geographic isolation, inadequate infrastructure, and limited medical resources. Communities in these regions face significant barriers in obtaining timely and adequate healthcare services, exacerbating public health issues. In response, artificial intelligence (AI) has emerged as a transformative technology, offering solutions that enhance healthcare systems by optimizing operational workflows, reducing human error, and improving resource management. When combined with sustainable design principles, AI-driven innovations provide a comprehensive approach to healthcare access and environmental sustainability. This paper presents a conceptual design proposal for a futuristic healthcare station aimed …

Cycling Network Planning Through Urban Form Analysis: A Contextual Gis Model, Nora Osama Ahmed, Rania Adham Sayed, Mona Mahrous Abdel Wahed

HBRC Journal

Promoting cycling as a sustainable mode of urban mobility requires a deep understanding of how urban form influences cyclists’ route choices. This study investigates the influence of urban form on cyclists’ route selection in an attempt to enhance context-sensitive cycling network planning. Five factors of urban form density, transportation infrastructure, housing/building type, land use, and street layout are examined to determine if any of them have a contributing factor to route selection. Based on an extensive review of the literature, the research develops an Urban Form–Cyclist Route Priority Matrix (UF-CRP Matrix) that categorizes urban conditions into three levels of desirability …

Performance Evaluation Of Sustainable Hot Mix Asphalt Using Construction Waste Materials, Mohamed A. Zaid, Ahmed E. Abu El-Maaty, Mohamed S. Ouf

HBRC Journal

This study aims to enhance sustainability, reduce environmental impact, minimize rutting, and improve performance by evaluating the use of construction material wastes. Ceramic waste powder (CWP), brick waste powder (BWP), and glass waste powder (GWP) were used as alternative fillers to conventional dolomite powder (DP) in hot-mix asphalt (HMA). The research investigates the effectiveness of these waste materials in improving asphalt performance, with the filler percentage fully replaced by these alternatives. Marshall Stability (MS), Marshall Quotient (MQ), moisture susceptibility, indirect tensile strength (IDT), and wheel tracking tests (WTT) were conducted to evaluate the impact of these waste materials on asphalt …

Eco Friendly Synthesis Of Copper Oxide Nanoparticles From Orange Peel Extract And Its Antimicrobial Studies, Rehab G. Hassan, Marwa M. El-Tyieb, N.Y Mohamed

HBRC Journal

The synthesis and stabilization of CuONPs at room temperature by using an aqueous extract of orange peel are described. The reason for the appearance of UV-vis absorption spectra peak at (∼439 nm) may be given as the evidence for forming CuONPs. In general, the XRD spectrum of the CuONPs agrees with the previous studies for Cu metal. Transmission Electron Microscopy exhibits irregular crystalline particles. Thus, the average particle size is ∼17 nm. CuONPs have shown potent bactericidal activities. The prepared CuONPs were applied against four pathogenic bacterial strains and three fungal strains as an antimicrobial agent. The inhibition growth zone …

Investigating Affordability Of Eco Housing With Ceb And Clustered Urban Form, Mohammad Fahmy, Ayman Ibrahim, Omar Galal

HBRC Journal

This study examines the affordability of eco-housing through the integration of Compressed Earth Blocks (CEB) and clustered urban form. It hypothesizes that the combined approach of sustainable building materials and climate-responsive neighbourhood planning enhances cost and energy efficiency while maintaining social housing accessibility. By assessing economic feasibility alongside environmental and urban design strategies, the research aims to provide insights into sustainable solutions towards future urban developments and a 5th generation for Egyptian cities. Computational simulations utilizing ENVI-met for urban microclimate assessment and Design Builder for indoor environment evaluation demonstrated improved results for outdoor and indoor environments. For outdoor assessment, design …

Correlations Between Geotechnical Parameters And Electrical Resistivity For Limestone At Beni Suef, Egypt, Gihan E. Abdelrahman, Elsayed A. Issawy, Walid I. Hammad, Ahmed A. Moheb

HBRC Journal

This study presents an integrated geotechnical–geophysical investigation of limestone formations in Ezbet Deir El-Hadid, Egypt. The research combines conventional geotechnical testing with two-dimensional (2D) electrical resistivity tomography (ERT) to develop a cost-effective subsurface characterization methodology. Forty-one boreholes (15–30 m depth) provided direct measurements of unconfined compressive strength (q_u) and rock quality designation (RQD), while twenty-five ERT profiles enabled spatial resistivity mapping. Three distinct geological conditions were identified: (1) intact limestone exhibiting resistivity of 21–602 Ω·m, (2) water-saturated zones with reduced resistivity (14–37 Ω·m), and (3) cavities showing higher resistivity (1,038–4,035 Ω·m). An optimized investigation protocol …

Factors Affecting The Cost Of Dynamic Architecture During The Execution Phase, Lamiaa Mohamed Said Elsherif, Eman N. Shaqour, Abdullah Badawy Mohammed, Sherif Mohamed Sabry El Attar

HBRC Journal

This study is part of a larger study on the factors affecting the cost of dynamic architecture during three phases (design, execution and operation), A research paper on the design phase has been published. and we will specialize in this research by studying the execution phase.

This research study is based on identifying the main factors affecting the cost of dynamic, buildings by conducting a questionnaire and analyzing it statistically by using IBM SPSS Statistics 25. To get to the definition of dynamic architecture and Types of movement directions in dynamic buildings.

By studying each of the principles of movement …

Assessment Of Urban Resiliance By Using (Ahp) In Relation With (Anp), Sara Mahmood Al-Jawari

HBRC Journal

Urban resilience is an important part of the sustainable urban development agenda, providing a proactive approach to the growing challenges within cities and making them more responsive and safer for the future. Therefore, the research problem was to ask: How can the integration of the Analytical Hierarchy Process (AHP) and Analytical Network Process (ANP) be used to determine which cities have the most resilient systems in the event of an emergency? It is assumed that the use of integration between the AHP and ANP will facilitate the initial assessment of the resilience of city systems and the development of policies …