Digital Commons Network^™

Legally Speaking- Music Modernization Act 2018, Anthony Paganelli, Bruce Strauch, Bryan M. Carson, Jack Montgomery

Against the Grain

No abstract provided.

Gender, Work-Family Overload, And Stigmatization: Academia As A Revealing Organizational Case, Mary Frank Fox

NSF Workshop Fostering Gender and Work-Life Inclusion for Faculty in Understudied Contexts: An Organizational Science Lens

No abstract provided.

Blind Spots In Work-Life Research Through A Global Lens: Toward A Model Of Intersectionality, Diversity And Inclusion, Michalle Mor Barak

NSF Workshop Fostering Gender and Work-Life Inclusion for Faculty in Understudied Contexts: An Organizational Science Lens

No abstract provided.

Marketing Study Of Parrish Library Of Management And Economics, Shan Lin, Bhuvan Jindal, Mrithula Suresh Babu, Kelly Adams, Tanner Mellon, Sairam Venkatasubramanian, Alexander Batta

Libraries Reports

No abstract provided.

Development And Impact Of Teacher Social Capital In An Engineering Education Teacher Professional Development Program, Wei Zakharov

Libraries Faculty and Staff Scholarship and Research

Teacher social capital is a set of social interaction assets such as collegiality and collaboration that enable teachers to work with each other in groups to improve teaching and learning. This results in instructional improvement and student success in school reform.

This study discusses how an engineering education teacher professional development program has developed an environment for long-term collegiality and collaboration among its teachers. Furthermore, the study presents an empirical evidence of the impact of teacher social capital on students’ engineering knowledge learning.

Ninety teachers and 621 students are examined in this program. The participants are from fifteen elementary schools …

A Quick Look At Nvivo, Margaret Phillips, Jing Lu

Libraries Faculty and Staff Scholarship and Research

NVivo (QSR International, n.d.a) is software developed by QSR International for qualitative data analysis, such as content analysis and narrative analysis. The software provides a workspace for researchers to store, manage, query, and analyze unstructureddata, including text, images, audio, video, and other data types. NVivo has been used inmany library and information science studies, including to analyze interview data (Wiley& Mischo, 2016), student assignments (Insua, Lantz, & Armstrong, 2018; Phillips & Zwicky, 2017), and survey data (Gibbs, Boettcher, Hollingsworth & Slania, 2012). NVivo allows users to complete multiple qualitative analysis functions on the platform, including sorting and filtering raw data, …

Mapping Information Literacy Using The Business Research Competencies, Heather A. Howard, Nora Wood, Ilana Stonebraker

Libraries Faculty and Staff Scholarship and Research

Purpose

Librarians in higher education have adopted curriculum mapping in an effort to determine where effective information literacy instruction can help fill gaps in curriculum and prepare students both for coursework and for future research demands. While curriculum mapping has been utilized widely across academia, few studies have considered business curriculum and the development of information literacy instruction. This paper will provide an overview of the current landscape of curriculum mapping across business courses at two institutions and will provide a replicable methodology for other institutions.

Design/methodology/approach

In this paper, the authors will examine two case studies at large research …

Effective Methods Of Engineering Information Literacy: Initial Steps Of A Systematic Literature Review And Observations About The Literature, Margaret Phillips, Amy Van Epps, Nastasha Johnson, Dave Zwicky

Libraries Faculty and Staff Scholarship and Research

Background – There is a body of information literacy (IL) literature applied to undergraduate engineering students, much of which discusses different methods for teaching, such as classes/one-shots, online tutorials, gaming, and other interventions. It is important for librarians to know which methods of teaching engineering information literacy (EIL) are most effective for student learning, in order to make efficient and effective use of student and librarian time.

Purpose/Hypothesis – The authors reviewed the existing literature to find indications of the most effective methods for teaching and/or integrating EIL, both in face-to-face and online instruction.

Design/Method – The authors have completed …

Information Literacy In Engineering Technology Education: A Case Study, Margaret Phillips, Dave Zwicky

Libraries Faculty and Staff Scholarship and Research

Information literacy is a vital component of engineering and engineering technology programs, as evidenced by its alignment with the engineering design process, and as required by ABET, the body that accredits all engineering and many engineering technology undergraduate programs. However, information literacy in engineering technology and applied engineering curricula is understudied when compared with information literacy in engineering programs. This paper describes a case study of information literacy integration into an undergraduate mechanical engineering technology design course, with a focus on patent information and patent searching. Online pre- and post-assessment data for four semesters were analyzed, showing improvements in student …

Informed Learning Design: Teaching And Learning Through Engagement With Information, Clarence Maybee, Christine Susan Bruce, Mandy Lupton, Ming Fai Pang

Libraries Faculty and Staff Scholarship and Research

While higher education teachers are able to use information in sophisticated ways to learn and communicate within their disciplines, they may not be accustomed to teaching their students to use information creatively and reflectively to support their work in a course. This paper introduces informed learning design, a curriculum design model by which teachers specifically enable students to learn course content through intentionally design engagement with information. Drawing from informed learning pedagogy and the variation theory of learning, the design model outlines an instructional pattern for enabling student awareness of critical aspects and features of the object being studied related …

Priests, Churros, And Treadles: Beyond The Trope Of Spanish Superiority, Dawn G. Marsh

Library Scholars Grant Program

No abstract provided.

Yale University Special Collections: Kevin Roche And John Dinkeloo, Jennifer Kaufmann-Buhler

Library Scholars Grant Program

No abstract provided.

Fred Waring And The Use Of Technology For Choral Singing, Cristopher Cayari

Library Scholars Grant Program

No abstract provided.

Frost Porosity Measurement Using Capacitive Sensor, Yuchen Shen, Yuheng Zhang, Xiaofei Wang

International Refrigeration and Air Conditioning Conference

Frosting is a dynamic process because of the changes in the frost-air interface temperature as the frost layer grows. The frost properties, such as frost density and frost porosity, are highly dependent on the frosting conditions and vary with time even under a constant environmental and operational conditions. Precise detection of frost properties is important for understanding frosting mechanisms and predicting frost growth, and it is also important for defrost control in many applications. So far there have been very few research reports on dynamic frost porosity measurement, and most work reports an average measurement approach, which is undertaken by …

Effect Of Fin Geometries On Condensation Heat Transfer And Pressure Drop Inside Horizontal Small-Diameter 4 Mm Microfin Tubes, Norihiro Inoue, Masataka Hirose, Daisuke Jige

International Refrigeration and Air Conditioning Conference

In the refrigeration and air-conditioning fields, small-diameter microfin tubes with an outside diameter of 5 mm or less have been developed; these tubes enhance energy savings by improving the performance of the heat exchanger and by reducing the charge amount of the refrigerant for downsizing the heat exchanger. Small-diameter microfin tubes with 4 mm outer diameters have been utilized as a part of practical applications. It is important to investigate heat transfer and pressure drop characteristics at lower mass velocities. Furthermore, hydrofluoroolefin (HFO) refrigerants have been recently attracting attention as low global warming potential (GWP) refrigerants. However, only limited studies …

Optimization Of Microgroove Copper Tube Coil Designs For Flammable Refrigerants, Nigel Cotton, Adam Rhoads, Anderson Bortoletto, Yoram Shabtay

International Refrigeration and Air Conditioning Conference

The ultralow Global Warming Potential (GWP) of propane (R290) and isobutane (R600a) refrigerants make them highly attractive for refrigerator and freezer applications, although their flammability necessitates strict use conditions with respect to refrigerant charge. Copper tubes with smaller diameters are widely used to reduce refrigerant charge. The process of downsizing copper-tube diameters involves detailed simulations and prototype construction as well as testing and validation. A proprietary heat exchanger design and simulation software tool (Jiang et al., 2006) was used to evaluate the performance of and optimize the design of domestic refrigerator condenser coils made with 5-mm outer-diameter copper tubes. Optimization …

Transient Simulation Of Secondary Loop Mobile Air Conditioning Systems, Zhenyuan Mei, Yunho Hwang, Jaeyeon Kim

International Refrigeration and Air Conditioning Conference

Since the conventional refrigerant R-134a is being phased down due to its high GWP, finding a suitable replacement refrigerant with low GWP and a system design is of great importance. However, most of the alternatives are either flammable or more expensive. Therefore, to ensure the safety of passenger and reduce the refrigerant charge, a secondary loop system with coolant loop on both condenser- and evaporator-side was proposed. In the secondary loop system, the evaporator and condenser exchange heat with air through cabin cooler and radiator, respectively. The secondary loop system has more advantages than the direct expansion system such as …

Separate Sensible And Latent Cooling Systems: A Critical Review Of The State-Of-The-Art And Future Prospects, Kashif Nawaz, Kyle Gluesenkamp

International Refrigeration and Air Conditioning Conference

Dehumidification is a major contributor to the energy consumed by residential and commercial buildings. The emergence of separate sensible and latent cooling (SSLC) systems have provided energy-efficient solutions to control moisture when compared to traditional vapor compression systems. However, a strong need has emerged to categorize and to characterize the performance of SSLC systems. The current study provides a critical review of major developments including components, systems and processes pertaining to SSLC systems. Additionally, various working media (solid and liquid desiccants and ionic fluids) have been explored to determine the potential merits and demerits. The review effort focuses on highlighting …

Design And Testing Of A Microchannel Heat Exchanger Working As Condenser And Evaporator, Emanuele Zanetti, Marco Azzolin, Stefano Bortolin, Giulio Busato, Davide Del Col

International Refrigeration and Air Conditioning Conference

In the recent years, international agreements and regulations urge for a reduction of production and utilization of Hydrofluorocarbons (HFCs), while achieving high efficiency remains a crucial aspect for refrigeration and air conditioning systems. One of the possible candidates to replace the high global warming potential (GWP) fluid currently employed in heat pump systems (R410A) is the refrigerant R32, which belongs to A2L class. In addition to adopting low-GWP refrigerants, charge minimization is a major design objective for such systems, mainly in the case of flammable refrigerants. In the case of reversible heat pumps, a reduced volume of the heat exchangers …

Steady-State Modeling Of Condensing Units With An Economizer Loop, Haithem Murgham, David Myszka, Vijay Bahel, Nathan Burns, Kyaw Wynn, Mike Saunders, Rajan Rajendran

International Refrigeration and Air Conditioning Conference

This paper presents an engineering model that simulates the steady-state operation of air-cooled condensing units. Packaged, air-cooled, condensing units includes a compressor, condensing coil, tubing, and fans, fastened to a base or installed within an enclosure. To increase capacity, modern condensing units are being equipped with a brazed-plate heat exchanger for an economizer loop, configured in either upstream or downstream extraction schemes.

Experimental Design And Laboratory Characterization Of A Medium- And High-Efficiency Rooftop Unit For Use In Building Energy Simulations, Grant Wheeler, Eric Kozubal, Ron Judkoff

International Refrigeration and Air Conditioning Conference

Commercial rooftop units (RTUs) that incorporate variable-speed components are quickly entering the marketplace; however, the design and modeling tools that calculate the energy benefits of these units cannot properly estimate performance. This is because 1) there are insufficient measured performance data of real systems that can be input into these simulations, and 2) building energy simulators are unable to properly interpret performance data. Therefore, publicly available data sets designed to encompass the entire performance map coupled with control sequence information are needed as inputs for these modeling programs to accurately estimate energy savings and promote the benefits of variable-speed RTUs. …

Cfd Case Study: Heat Exchanger Inlet Air Velocity Distribution For Ducted Tests In A Psychrometric Chamber (Ashrae Rp-1785), Juseok{Abraham} Lee, Christian K. Bach, Craig Bradshaw

International Refrigeration and Air Conditioning Conference

This paper presents the airside analysis of coil duct configurations using Computational Fluid Dynamics (CFD) to determine which configuration best mitigates airside maldistribution for ASHRAE RP-1785. RP-1785 has a global objective of providing accurate refrigerant charge and oil retention data for residential coils, collected in a controlled experiment. The final test matrix of the study includes several representative residential indoor and outdoor coils to be tested at various refrigerant and airside inlet conditions. The coil performance, charge, and oil retention behavior is strongly influenced by the airflow; therefore the uniform airflow distribution to coils is critical to RP-1785 to maintain …

Development Of A Fast Method For Retrieving Thermodynamic Properties To Accelerate Transient Vapor Compression Cycle Simulation, Jiacheng Ma, Donghun Kim, James E. Braun

International Refrigeration and Air Conditioning Conference

It has been previously demonstrated that the most significant computational requirements for vapor compression system models are associated with evaluation of thermodynamic properties. This is particularly important for transient models because properties are evaluated at each time step and the overall model can often run less than real time. The typical approach for evaluating thermodynamic properties involves the use of complicated equations of state (EOS), such as utilized in standard software tools such as RefProp and CoolProp. Overall computation speed can be significantly enhanced using interpolation methods that are based on pre-calculated thermodynamic properties. This paper presents an improved interpolation …

Novel Vapor Compression Cycles With High Energy Efficiency Using Natural Refrigerants For Three Kinds Of Appliances, Jianhua Wu, Jiachen Li

International Refrigeration and Air Conditioning Conference

Natural refrigerants are eco-friendly substitutes for HCFCs and HFCs in vapor compression cycles, such as refrigeration or heat pump cycles. In this paper, three appliance systems are analyzed based on refrigerants characteristics for performance improvement, and novel and practical cycles are proposed and briefly analyzed. Dual-evaporator (DE) cycle for refrigerator can reduce the irreversible thermodynamic loss in one-stage cycle. Rotary compressors which have advantages in efficiency and dynamic balance capability are highly suitable to DE cycles. The improvement of theoretical refrigeration coefficient for DE cycle is up to 24.4% comparing with conventional one-stage cycle under refrigerator condition. Vapor injection heat …

Application Of Bifurcated Bare-Tube Heat Exchanger On Water-Based Hybrid Vrf System, Zhiwei Huang, Ransisi Huang, Jiazhen Ling, Vikrant Chandramohan Aute, Yunho Hwang

International Refrigeration and Air Conditioning Conference

Variable refrigerant flow (VRF) system can achieve higher efficiency by modulating the flow of refrigerant according to individual area’s cooling and heating load than traditional central air conditioning unit. A water-based hybrid VRF system is a combination of traditional VRF system and water chiller system. Instead of using refrigerant inside building, hybrid VRF system utilizes water (or any heat transfer fluid) coils as indoor units. Compared with traditional VRF system, it has the advantages of reduced refrigerant charge, wider selection of refrigerants including flammability and lower maintenance cost since there is no concern for indoor refrigerant leakage . A field …

All-Year Vehicle Simulation With Analysis Of Capacity Control Of R-134a And R-744 Piston Compressors For Coach Hvac Systems, Nicholas Carsten Lemke, Christian Kaiser, Wilhelm Tegethoff, Jürgen Köhler

International Refrigeration and Air Conditioning Conference

The reheating of cooled air is the state-of-the-art for controlling the air-side cooling capacity in conventional omnibus HVAC systems. This method is pragmatic, albeit highly energy-inefficient. This paper deals with the structured analysis and improvement of capacity regulation for a conventional system using the example of a coach air conditioning system. Piston compressors are typically used in the air conditioning systems for conventional buses. This compressor type belongs to the group of reciprocating compressors and is a common standard in the constant displacement version for large refrigerant systems in the omnibus sector. The compressor is usually driven directly by the …

Thermoeconomic Diagnosis Of Air Conditioning Systems: Experimental Assessment Of Performance And New Developments For Improved Reliability, Pietro Catrini, James E. Braun, Antonio Piacentino, Andrew L. Hjortland, Akash Patil

International Refrigeration and Air Conditioning Conference

In the last two decades, great progress has been made in improving the efficiency of air-conditioning equipment. In addition to improved performance of new equipment, there has been an increasing interest in technologies that can maintain performance over time. This has led to research and development of Fault Detection and Diagnosis (FDD) techniques for air conditioning systems, that can support building owners in scheduling cost-effective maintenance and repairs. Among FDD techniques, thermoeconomic diagnosis is a novel method for the identification of faults occurring in air conditioning systems. A very limited number of papers have focused on this topic, and the …

New Solutions For Household Refrigerator Performance Improvement, Andre Morriesen, Marcio Roberto Thiessen, Adriano Francisco Ronzoni, Daniel Hense, Jackson Karnopp, João Lemos Junior, Fabio Allan Schulze

International Refrigeration and Air Conditioning Conference

This paper presents some experimental results of two alternative solutions to improve household refrigerators energy consumption, the flooded evaporator architecture and the pulse width modulation (PWM) control logic for a variable capacity compressor. The experiments were carried out in a 360-liters bottom-mounted refrigerator-freezer, with natural draft evaporators, at two different ambient temperatures: 16°C and 32°C. The flooded evaporator solution can imply the same performance of the parallel circuit but with the simplicity of the serial-hybrid circuit, demanding no check valve nor need for pump out. The flooded evaporator circuit has a liquid accumulator connecting the evaporator’s outlet, which allows working …

Heat Transfer Enhancement Using Approximation Assisted Optimization For Pillow Plate Heat Exchangers, Radia Eldeeb, Jiazhen Ling, Vikrant Chandramohan Aute, Reinhard Radermacher

International Refrigeration and Air Conditioning Conference

Optimization is a powerful mathematical methodology that can be employed to miniaturize and improve the performance of plate heat exchangers in order to achieve higher levels of energy efficiency. Achieving these goals means less material used, and less charge, and thus a lower impact on the environment Plate heat exchangers (PHXs) are favored by the HVAC&R industry since they combine between the advantages of compactness, and desirable thermal-hydraulic characteristics due to their small approach temperature. However, the challenge with plate heat exchangers lies within the costly new designs. Pillow plate heat exchanger (PPHX) is a promising type of PHXs which …

Efficiency Enhancement By Subcooling The Carbon Dioxide Process With Water As Refrigerant, Florian Hanslik, Juergen Suess, Juergen Koehler

International Refrigeration and Air Conditioning Conference

As a consequence of the F-Gas regulation R404A is no longer an option for commercial refrigeration applications. Therefore, this paper focuses on natural refrigerants. There are a few options like carbon dioxide, which has an efficiency loss with increasing ambient temperatures. A promising option is subcooling of the carbon dioxide process with a chiller using water as the refrigerant. This will result in a new optimized high pressure of the carbon dioxide process depending on the ambient temperature. Finally the annual COP values of the standard transcritical and subcooled system will be discussed.