Digital Commons Network^™

Characterization Of Coherent Quantum Frequency Combs Using Electro-Optic Phase Modulation, Poolad Imany, Ogaga D. Odele, Jose A. Jaramillo-Villegas, Daniel E. Leaird, Andrew M. Weiner

Department of Electrical and Computer Engineering Faculty Publications

We demonstrate a two-photon interference experiment for phase coherent biphoton frequency combs (BFCs), created through spectral amplitude filtering of biphotons with a continuous broadband spectrum. By using an electro-optic phase modulator, we project the BFC lines into sidebands that overlap in frequency. The resulting high-visibility interference patterns provide an approach to verify frequency-bin entanglement even with slow single-photon detectors; we show interference patterns with visibilities that surpass the classical threshold for qubit and qutrit states. Additionally, we show that with entangled qutrits, two-photon interference occurs even with projections onto different final frequency states. Finally,we showthe versatility of this scheme for …

High-Order Coherent Communications Using Modelocked Dark-Pulse Kerr Combs From Microresonators, Attila Fülöp, Mikael Mazur, Abel Lorences-Riesgo, Óskar B. Helgason, Pei-Hsun Wang, Yi Xuan, Daniel E. Leaird, Minghao Qi, Peter A. Andrekson, Andrew M. Weiner, Victor Torres-Company

Department of Electrical and Computer Engineering Faculty Publications

Microresonator frequency combs harness the nonlinear Kerr effect in an integrated optical cavity to generate a multitude of phase-locked frequency lines. The line spacing can reach values in the order of 100 GHz, making it an attractive multi-wavelength light source for applications in fiber-optic communications. Depending on the dispersion of the microresonator, different physical dynamics have been observed. A recently discovered comb state corresponds to the formation of mode-locked dark pulses in a normal-dispersion microcavity. Such dark-pulse combs are particularly compelling for advanced coherent communications since they display unusually high power-conversion efficiency. Here, we report the first coherent-transmission experiments using …

Measurement Of The Lifetime Of The 7s2s1/2 State In Atomic Cesium Using Asynchronous Gated Detection, George Toh, Jose A. Jaramillo-Villegas,, Nathan Glotzbach, Jonah Quirk, Ian C. Stevenson, Andrew M. Weiner

Department of Electrical and Computer Engineering Faculty Publications

We report a measurement of the lifetime of the cesium 7s 2S1/2 state using time-correlated single-photon counting spectroscopy in a vapor cell. We excite the atoms using a Doppler-free two-photon transition from the 6s 2S1/2 ground state, and detect the 1.47-μm photons from the spontaneous decay of the 7s 2S1/2 to the 6p 2P3/2 state. We use a gated single-photon detector in an asynchronous mode, allowing us to capture the fluorescence profile for a window much larger than the detector gate length. Analysis of the exponential decay of the photon count yields a 7s 2S1/2 lifetime of 48.28 ± 0.07 …

Observation Of Breathing Dark Pulses In Normal Dispersion Optical Microresonators, Chengying Bao, Yi Xuan, Cong Wang, Attila Fülöp, Daniel E. Leaird, Victor Torres-Company, Minghao Qi, Andrew M. Weiner

Department of Electrical and Computer Engineering Faculty Publications

Breathers are localized waves in nonlinear systems that undergo a periodic variation in time or space. The concept of breathers is useful for describing many nonlinear physical systems including granular lattices, Bose-Einstein condensates, hydrodynamics, plasmas, and optics. In optics, breathers can exist in either the anomalous or the normal dispersion regimes, but they have only been characterized in the former, to our knowledge. Here, externally pumped optical microresonators are used to characterize the breathing dynamics of localized waves in the normal dispersion regime. High-Q optical microresonators featuring normal dispersion can yield mode-locked Kerr combs whose time-domain waveform corresponds to circulating …

A Validated Time-Stepping Analytical Model For 3d Transient Vapor Chamber Transport, G. Patankar, J. A. Weibel, S V. Garimella

CTRC Research Publications

Advances in the computational performance of electronic devices have created a clear need for improved methods of passive thermal management. This has led to renewed interest in the use of vapor chambers as heat spreaders in applications ranging from mobile devices to high-performance-computing and power electronics systems. While there has been significant effort to develop vapor chambers for these applications, their designs have largely relied on steady-state analyses and performance prediction. In many applications, however, the heat load is inherently transient in nature. Heat spreader design must consider transient performance in response to these use-case scenarios. While detailed numerical models …

Expanding The Global Reach Of The Twenty-First-Century Research University, S V. Garimella

CTRC Research Publications

No abstract provided.

Tears Of An Evaporating Meniscus On A Silicon Substrate, M. Chakraborty, J. A. Weibel, S V. Garimella

CTRC Research Publications

We identify the formation of an unstable rim at the three-phase contact line of an evaporating methanol meniscus due to the autophobic nature of the liquid. Undulations along the rim rupture at a consistent frequency, leaving behind a regular pattern of droplet tears as the contact line recedes. We characterize the geometry and undulation dynamics of the rim. The rim movement exhibits slip at the contact line; the measured ratio of rim width to undulation wavelength matches the critical unstable Rayleigh ratio for an intermediate slip regime. Unlike previously observed rim instabilities, the rim volume here is replenished from the …

Characterization Of Hierarchical Manifold Microchannel Heat Sink Arrays Under Simultaneous Background And Hotspot Heating Conditions, K. P. Drummond, D. Back, M. D. Sinanis, D. B. Janes, D. Peroulis, J. A. Weibel, S V. Garimella

CTRC Research Publications

A hierarchical manifold microchannel heat sink array is fabricated and experimentally characterized for uniform heat flux dissipation over a footprint area of 5 mm x 5 mm. A 3 x 3 array of heat sinks is fabricated into the silicon substrate containing the heaters for direct intrachip cooling, eliminating the thermal resistances typically associated with the attachment of a separate heat sink. The heat sinks are fed in parallel using a hierarchical manifold distributor that delivers flow to each of the heat sinks. Each heat sink contains a bank of high-aspect-ratio microchannels; five different channel geometries with nominal widths of …

Metallized Compliant Three-Dimensional Microstructures For Dry Contact Thermal Conductance Enhancement, J. Cui, J. Wang, Y. Zhong, L. Pan, J. A. Weibel

CTRC Research Publications

Microstructured three-dimensional (3D) materials can be engineered to enable new capabilities for various engineering applications; however, microfabrication of large 3D structures is typically expensive due to the conventional top-down fabrication scheme. Herein we demonstrated the use of projection micro-stereolithography and electrodeposition as cost-effective and high-throughput methods to fabricate compliant 3D microstructures as a thermal interface material (TIM). This novel TIM structure consists of an array of metallized micro-springs designed to enhance the dry contact thermal conductance between nonflat surfaces under low interface pressures (10s–100s kPa). Mechanical compliance and thermal resistance measurements confirm that this dry contact TIM can achieve conformal …

High‐Frequency Thermal‐Fluidic Characterization Of Dynamic Microchannel Flow Boiling Instabilities: Part 2 ‐ Impact Of Operating Conditions On Instability Type And Severity, T. A. Kingston, J. A. Weibel, S V. Garimella

CTRC Research Publications

Dynamic instabilities during flow boiling in a uniformly heated microchannel are investigated. The focus of this Part 2 of the study is on the effect of operating conditions on the instability type and the resulting time-periodic hydrodynamic and thermal oscillations, which have been established after the initial boil- ing incipience event. Part 1 of this study investigated the rapid-bubble-growth instability at the onset of boiling in the same experimental facility. Fluid is driven through the single 500 μm-diameter glass mi- crochannel by maintaining a constant pressure difference between a pressurized upstream reservoir and a reservoir downstream that is open to …

Physiological And Behavioral Effects Of Animal-Assisted Interventions For Therapy Dogs In Pediatric Oncology Settings, Amy Mccullough, Molly Jenkins, Ashleigh Ruehrdanz, Mary Jo Gilmer, Janice Olson, Anjali Pawar, Leslie Holley, Shirley Sierra-Rivera, Deborah E. Linder, Danielle Pinchette, Neil J. Grossman, Cynthia Hellman, Noémie Guérin, Marguerite O'Haire

Department of Comparative Pathobiology Faculty Publications

Over the past two decades, animal-assisted interventions (AAIs), defined as the purposeful incorporation of specially trained animals in services to improve human health, have become increasingly popular in clinical settings. However, to date, there have been few rigorously-designed studies aimed at examining the impact of AAIs on therapy animals, despite a notable potential for stress. The current study measured physiological and behavioral stress indicators in therapy dogs who participated in AAI sessions in pediatric oncology settings, while also examining the psychosocial effects for patients and their parents. This manuscript describes the study’s canine stress findings. Methods: A total of 26 …

Enabling Highly Effective Boiling From Superhydrophobic Surfaces, T. Allred, J. A. Weibel, S V. Garimella

CTRC Research Publications

Avariety of industrial applications such as power generation, water distillation, and high-density cooling rely on heat transfer processes involving boiling. Enhancements to the boiling process can improve the energy efficiency and performance across multiple industries. Highly wetting textured surfaces have shown promise in boiling applications since capillary wicking increases the maximum heat flux that can be dissipated. Conversely, highly nonwetting textured (superhydrophobic) surfaces have been largely dismissed for these applications as they have been shown to promote formation of an insulating vapor film that greatly diminishes heat transfer efficiency. The current Letter shows that boiling from a superhydrophobic surface in …

Research On The Application Of Rotary Compressor With Two Independent Suction Pressures On Fresh Air-Conditioning System, Lei Zhang, Chunhui Liu

International Compressor Engineering Conference

A compressor with two independent suction pressures is presented in this paper, which can be applied to the household fresh air conditioning system of independent control temperature and humidity (two evaporation temperature). This paper introduces the working principle, structural characteristics and the characteristics of working conditions. Through simulation calculation and experimental verification, the energy efficiency of the fresh air conditioning system with two suction pressures compressor is much higher than that of the traditional fresh air air-conditioning system. There is a broad application market in the field of household fresh air-conditioning system for the rotary compressor of two independent suction …

Parallel Vs. Serial Noise Suppression Method For Positive Displacement (Pd) Compressors & Internal Combustion Engines (Ice), Paul Xiubao Huang Dr., Eckhard A. Groll, Sean Yonkers

International Compressor Engineering Conference

Positive displacement (PD) compressors and internal combustion engines (ICEs) are major energy consumers. For example, a typical US household may have as many as 7 compressors (2 in house AC, 2 in auto AC, 1 each for refrigerator or freezer or shop compressed air) and 4 ICEs (2 in auto, 1 each for lawn mower and auxiliary power generator). However, they both generate high amplitude pulsating pressures1 (up to 180-200 dB) and discharge flows that demand a silencer or muffler to suppress the noise but leads to high energy costs: up to 5-7% shaft power for PD compressors and up …

Three-Dimensional Navier-Stokes Simulations Of Working Of Scroll Compressors, Alain Picavet, David Genevois

International Compressor Engineering Conference

Danfoss Commercial Compressors is going on with detailed studies of the compression process in scroll compressors. Three-dimensional Navier-Stokes simulations are performed from the intake of the wraps until the exit of the machines, using moving meshes and a real gas equation for the R410A. Various operating points and rotation velocities are computed. The results are compared with detailed pressure measurements realized previously and already exposed at the Purdue Conference. The new technique of meshing, with generation of high quality structured grids for the mobile part, allows to compute quickly and with accuracy. The comparisons between computed and measured data show …

Cfd Simulation Of A Two Stage Twin Screw Compressor Including Leakage Flows And Comparison With Experimental Data, Rainer Andres, Jan Hesse, Farai Hetze, Donald Low

International Compressor Engineering Conference

Computational Fluid Dynamics (CFD) is a common and validated simulation method in research and industry for the analysis of fluid systems. In the past years, it has proven to become more and more applicable for modeling the flow physics inside positive displacement (PD) machines. The working chamber and thus the discretized flow domain of PD machines is changing in time and characterized by complex thermodynamics. Compressible fluids, real-gas properties and leakage flows with trans- or supersonic characteristics are phenomena which have to be accounted for in order to properly model the behavior of the machine. As CFD methods evolve in …

Development Of An Evolutionary Three-Dimensional Scroll Compressor, Hajime Sato, Youhei Hotta, Yoshiyuki Kimata, Takahide Ito, Takuma Yamashita

International Compressor Engineering Conference

A novel three-dimensional scroll compressor was developed. The authors have produced 3D scroll compressor since 2004. The 3D scroll is able to compress refrigerant in axial direction as well as in existing radial direction by employing steps at the bottom and the tip of the scroll which change the height of compression chamber on the middle of the compression process. For the purpose of further performance improvement, the authors developed an evolutionary three-dimensional compression mechanism, named "e-3D scroll". The e-3D scroll is equipped with a sloped tip and a sloped end plate in each scroll instead of the steps in …

The Effect Of Lateral Thermal Coupling Between Parallel Microchannels On Two‐Phase Flow Distribution, T. Van Oevelen, J. A. Weibel, S V. Garimella

CTRC Research Publications

Evaporating flows in parallel channels occurring in a variety of industrial heat exchange processes can encounter non-uniform flow distribution between channels as a result of two-phase flow instabilities. Such flow maldistribution can have a negative impact on the performance, robustness and predictability of these systems. Two-phase flow modeling can assist in understanding the mechanistic behavior of this flow maldistribution, as well as determine parametric trends and identify safe operating conditions.

The work described in this paper expands on prior two-phase flow distribution modeling efforts by including and assessing the effect of thermal conduction in the walls surrounding the parallel channels. …

Calibration And Uncertainty Analysis Of A Fixed-Bed Adsorption Model For Co2 Separation, K. N. Son, J. A. Weibel, J. C. Knox, S V. Garimella

CTRC Research Publications

Fixed-bed adsorption is widely used in industrial gas separation and is the primary method for atmosphere revitalization in space. This paper analyzes the uncertainty of a one-dimensional, fixed-bed adsorption model due to uncertainty in several model inputs, namely, the linear-driving-force (LDF) mass transfer coefficient, axial dispersion, heat transfer coefficients, and adsorbent properties. The input parameter uncertainties are determined from a comprehensive survey of experimental data in the literature. The model is first calibrated against experimental data from intra-bed centerline concentration measurements to find the LDF coefficient. We then use this LDF coefficient to extract axial dispersion coefficients from mixed, downstream …

High‐Frequency Thermal‐Fluidic Characterization Of Dynamic Microchannel Flow Boiling Instabilities: Part 1 ‐ Rapid‐Bubble‐Growth Instability At The Onset Of Boiling, T. A. Kingston, J. A. Weibel, S V. Garimella

CTRC Research Publications

Dynamic flow boiling instabilities are studied experimentally in a single, 500 μm-diameter glass mi- crochannel subjected to a uniform heat flux. Fluid flow is driven through the microchannel in an open- loop test facility by maintaining a constant pressure difference between a pressurized upstream reservoir and a reservoir at the exit that is open to the ambient; the working fluid is HFE-7100. This hydrodynamic boundary condition resembles that of an individual channel in a parallel-channel heat sink where the channel mass flux can vary in time. Simultaneous high-frequency measurement of reservoir, inlet, and outlet pressures, pressure drop, mass flux, inlet …

Pumpkin Variety Performance With And Without Treatment For Powdery Mildew In Northern Indiana, 2017, Elizabeth Maynard, Erin A. Bluhm

Purdue Fruit and Vegetable Research Reports

Pumpkins are grown on 5,000 acres in Indiana with an average yield of 6.75 tons per acre. Successful pumpkin production requires the use of varieties that yield well and produce pumpkins of the size, shape, color, and quality demanded by the market. Genetic resistance to the fungal disease powdery mildew is present in some varieties. This trial was designed to evaluate performance of pumpkin varieties in northern Indiana with and without treatment for powdery mildew. The trial included fourteen orange jack-o-lantern size pumpkins, one small or 'pie' pumpkin and one specialty yellow pumpkin.

A Longitudinal Analysis On The Feasibility Of Iris Recognition Performance For Infants 0-2 Years Old, Torrey Hutchison

Purdue Polytechnic Masters Theses

The focus of this study was to longitudinally evaluate iris recognition for infants between the ages of 0 to 2 years old. Image quality metrics of infant and adult irises acquired on the same iris camera were compared. Matching performance was evaluated for four groups, infants 0 to 6 months, 7 to 12 months, 13 to 24 months, and adults. A mixed linear regression model was used to determine if infants’ genuine similarity scores changed over time. This study found that image quality metrics were different between infants and adults but in the older group, (13 to 24 months old) …

Engineering Technology And Engineering Program Comparison Of Underrepresented Students In The Same Institution, Anne M. Lucietto, Lesley M. Berhan

School of Engineering Technology Faculty Publications

Engineering programs include far fewer African American students than engineering technology students enrolled in four-year programs at universities offering both ABET accredited programs. Several studies show this contrast, suggesting that further research in this area is warranted. The rationale for the higher population of students consistently in one program over the other is generally unknown. While researchers study the engineering population, the engineering technology population goes relatively unnoticed. The effects of a student’s past and current environments in engineering technology are relatively unknown. Researchers developed a survey to gather data from underrepresented populations in universities that meet the noted criteria. …

International Experience Of Engineering Technology Students Learning About Renewable Energy, Anne M. Lucietto

School of Engineering Technology Faculty Publications

Cultural exposure is said to be an enhancement to collegial learning. With this in mind, students in an engineering technology program were given the opportunity to go to Germany to a regional university, experience education in that setting, and visit sites dedicated to renewable energy. The students were given a two-week experience that taught them through both formal and informal means. Ultimately, students experienced curiosity, openness to different cultural norms, and were able to identify components of other cultural perspectives responding with their own worldviews. The researchers utilized the Miville-Guzman Universality Diversity Scale (M-GUDS-S) to assess pre and post activity …

Engineering Technology Students: Do They Approach Capstone Courses Differently Than Other Students?, Frederick Berry, Anne M. Lucietto, Andrew Scott

School of Engineering Technology Faculty Publications

Using data collected from students in engineering technology, engineering, and other areas such as computer science a comparison of student reactions to the capstone course are coded and sorted. Using content analysis methods, the researchers compare and contrast the various student groups and their reactions to assigned capstone projects. They are also able to assess student interaction with faculty and industry mentors. Researchers strive to learn more about these various student approaches to the capstone experience and to further our understanding of best practices in capstone courses.

Stem Educators: Who Are They?, Anne M. Lucietto, Liza Ann Russell

School of Engineering Technology Faculty Publications

Technical education or STEM (Science, Technology, Engineering, and Mathematics) education is often touted as the way for students to succeed, for corporations to move forward, and to gain prominence in the world economy. With all this promotion, do we know who is teaching these subjects to our students? This question urged researchers to develop a survey and distribute it to those teaching STEM subjects. The survey collected a variety of information, the results of the demographic section being reported here. The survey responses are from a population of STEM educators teaching at all levels, found to be male and generally …

Incorporating Engineering And Renewable Technologies Into The K-5 Classroom Through Culturally Relevant Literature And Design Challenges, Lisa Bosman, Kelli L. Chelberg, Greg Strimel

Technology Leadership and Innovation Faculty Publications

No abstract provided.

Performance Modeling And Valuation Of Snow-Covered Pv Systems: Examination Of A Simplified Approach To Decrease Forecasting Error, Lisa Bosman, Seth B. Darling

Technology Leadership and Innovation Faculty Publications

The advent of modern solar energy technologies can improve the costs of energy consumption on a global, national, and regional level, ultimately spanning stakeholders from governmental entities, to utility companies, corporations, and residential homeowners. For those stakeholders experiencing the four seasons, accurately accounting for snow-related energy losses is important for effectively predicting photovoltaic performance energy genreation and valuation. This paper provides an examination of a new, simplified approach to decrease snow-related forecasting error, in comparison to current solar energy performance models. A new method is proposed to allow model designers, and ultimately users, the opportunity to better understand the return …

Optimizing Library Services — The Natural Role Of The Public Library In Emergency Management, Lindsay Wertman, Caroline J. Campbell, Michael R. Mabe, Jeffrey M. Kenton

Against the Grain

No abstract provided.

Teaming Up With Faculty: A New Tactic In The Textbook Battle, Christa Bailey, Adriana Poo

Against the Grain

No abstract provided.