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Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim 2019 Singh Center for Nanotechnology

Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim

Tool Data

S1805 positive photoresist has been deposited on single crystalline Si wafers using a Suss MicroTec Alta Spray. The influence of flow rate, nozzle speed, pitch and number of passes on the thickness of the photoresist was studied. Results show that the thickness of S1805 is linearly proportional to the flow rate and number of passes, and inversely proportional to the nozzle speed and pitch.


Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng 2019 Iowa State University and Ames Labortory

Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng

Valery I. Levitas

Various phenomena (fracture, phase transformations, and chemical reactions) studied under extreme pressures in diamond anvil cell are strongly affected by fields of all components of stress and plastic strain tensors. However, they could not be measured. Here, we suggest a coupled experimental−theoretical−computational approach that allowed us (using published experimental data) to refine, calibrate, and verify models for elastoplastic behavior and contact friction for tungsten (W) and diamond up to 400 GPa and reconstruct fields of all components of stress and large plastic strain tensors in W and diamond. Despite the generally accepted strain-induced anisotropy, strain hardening, and path-dependent ...


Nurbs-Based Microstructure Design For Organic Photovoltaics, Ramin Noruzi, Sambit Ghadai, Onur Rauf Bingol, Adarsh Krishnamurthy, Baskar Ganapathysubramanian 2019 Iowa State University

Nurbs-Based Microstructure Design For Organic Photovoltaics, Ramin Noruzi, Sambit Ghadai, Onur Rauf Bingol, Adarsh Krishnamurthy, Baskar Ganapathysubramanian

Baskar Ganapathysubramanian

The microstructure – spatial distribution of electron donor and acceptor domains – plays an important role in determining the photo current in thin film organic solar cells (OSCs). Optimizing the microstructure can lead to higher photo current generation, and is an active area of experimental research. There has been recent progress in framing OSC microstructure design as a computational design problem. However, most current approaches to microstructure optimization are based on volumetric distribution of material, which makes the design space very large. In contrast, we frame the microstructure design optimization problem in terms of designing the interface between the donor and acceptor ...


Interpretable Deep Learning For Guided Microstructure-Property Explorations In Photovoltaics, Balaji Sesha Sarath Pokuri, Sambuddha Ghosal, Apurva Kokate, Soumik Sarkar, Baskar Ganapathysubramanian 2019 Iowa State University

Interpretable Deep Learning For Guided Microstructure-Property Explorations In Photovoltaics, Balaji Sesha Sarath Pokuri, Sambuddha Ghosal, Apurva Kokate, Soumik Sarkar, Baskar Ganapathysubramanian

Baskar Ganapathysubramanian

The microstructure determines the photovoltaic performance of a thin film organic semiconductor film. The relationship between microstructure and performance is usually highly non-linear and expensive to evaluate, thus making microstructure optimization challenging. Here, we show a data-driven approach for mapping the microstructure to photovoltaic performance using deep convolutional neural networks. We characterize this approach in terms of two critical metrics, its generalizability (has it learnt a reasonable map?), and its intepretability (can it produce meaningful microstructure characteristics that influence its prediction?). A surrogate model that exhibits these two features of generalizability and intepretability is particularly useful for subsequent design exploration ...


A Multi-Stage Optimization Model For Flexibility In Engineering Design, Ramin Giahi, Cameron A. MacKenzie, Chao Hu 2019 Iowa State University

A Multi-Stage Optimization Model For Flexibility In Engineering Design, Ramin Giahi, Cameron A. Mackenzie, Chao Hu

Cameron A. MacKenzie

Engineered systems often operate in uncertain environments. Understanding different environments under which a system will operate is important in engineering design. Thus, there is a need to design systems with the capability to respond to future changes. This research explores designing a hybrid renewable energy system while taking into account long-range uncertainties of 20 years. The objective is to minimize the expected cost of the hybrid renewable energy system over the next 20 years. A design solution may be flexible, which means that the design can be adapted or modified to meet different scenarios in the future. The value of ...


Achieving Energy Justice In Low Income Communities: Creating A Community-Driven Program For Residential Energy Savings, Anya Galli Robertson, Kevin Hallinan, Jennifer Hoody 2019 University of Dayton

Achieving Energy Justice In Low Income Communities: Creating A Community-Driven Program For Residential Energy Savings, Anya Galli Robertson, Kevin Hallinan, Jennifer Hoody

Conference: The Social Practice of Human Rights

The cost of residential energy the U.S. is unequally distributed, with low income households paying higher rates and spending 16.8% of their income on utility bills compared to 3.5% of all U.S. Residents.[1] Researchers have found that bringing the housing stock up to the efficiency of the median household would reduce excess energy cost by as much as 68%.[2] However, access to opportunities to reduce residential energy consumption and costs such as tax incentives and utility rebate programs tends to be biased toward wealthier, white homeowners. Additionally, low income residents are most likely to ...


Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang 2019 The University of Texas Rio Grande Valley

Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang

Mechanical Engineering Faculty Publications and Presentations

A new humidification-dehumidification (HDH) desalination process is proposed and analyzed. Being ocean based, the process does not produce any brine. It is largely powered jointly by solar energy, wind energy, and various types of ocean energies in a nearly natural way. A vacuum pump is employed to drive the air circulation throughout the HDH process. It is the only unit that consumes electricity. The HDH process is analyzed under various conditions, including using a low pressure (as low as to 0.2 atm) for humidification and the ambient pressure for dehumidification, running the entire HDH process around a low pressure ...


Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng 2019 Iowa State University and Ames Labortory

Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng

Aerospace Engineering Publications

Various phenomena (fracture, phase transformations, and chemical reactions) studied under extreme pressures in diamond anvil cell are strongly affected by fields of all components of stress and plastic strain tensors. However, they could not be measured. Here, we suggest a coupled experimental−theoretical−computational approach that allowed us (using published experimental data) to refine, calibrate, and verify models for elastoplastic behavior and contact friction for tungsten (W) and diamond up to 400 GPa and reconstruct fields of all components of stress and large plastic strain tensors in W and diamond. Despite the generally accepted strain-induced anisotropy, strain hardening, and path-dependent ...


Interpretable Deep Learning For Guided Microstructure-Property Explorations In Photovoltaics, Balaji Sesha Sarath Pokuri, Sambuddha Ghosal, Apurva Kokate, Soumik Sarkar, Baskar Ganapathysubramanian 2019 Iowa State University

Interpretable Deep Learning For Guided Microstructure-Property Explorations In Photovoltaics, Balaji Sesha Sarath Pokuri, Sambuddha Ghosal, Apurva Kokate, Soumik Sarkar, Baskar Ganapathysubramanian

Mechanical Engineering Publications

The microstructure determines the photovoltaic performance of a thin film organic semiconductor film. The relationship between microstructure and performance is usually highly non-linear and expensive to evaluate, thus making microstructure optimization challenging. Here, we show a data-driven approach for mapping the microstructure to photovoltaic performance using deep convolutional neural networks. We characterize this approach in terms of two critical metrics, its generalizability (has it learnt a reasonable map?), and its intepretability (can it produce meaningful microstructure characteristics that influence its prediction?). A surrogate model that exhibits these two features of generalizability and intepretability is particularly useful for subsequent design exploration ...


The Improvement Of The Solar Air Heater Duct By Wired Ribs Utilization, Osamah Raad skheel/alkhafaji 2019 Middle Technical University, Baghdad, Iraq

The Improvement Of The Solar Air Heater Duct By Wired Ribs Utilization, Osamah Raad Skheel/Alkhafaji

Karbala International Journal of Modern Science

Abstract Heat transfer coefficient of the solar air heater duct (SAH) is low due increasing the thermal performance of its absorber. The present study tends to enhance the thermal characteristics of the SAH by adopting the wired ribs on the absorber under different ribs dimensions and arrangements. A rectangular duct is used to form the SAH with length L=1500mm, width w=100mm and height H=30mm. The used heat fluxes over the absorber are 1000W/m2 and 500W/m2 while the operated Reynolds number range is 708 ~ 6375. The utilized wired ribs are arranged over the absorber so as ...


Analytical Approach To Investigation Of Free Vibration Of Thin Rectangular Plate Immersed In Fluid, Resting On Winkler And Pasternak Foundations, Obanishola Sadiq, Gbeminiyi Sobamowo, Saheed Salawu 2019 University of Lagos

Analytical Approach To Investigation Of Free Vibration Of Thin Rectangular Plate Immersed In Fluid, Resting On Winkler And Pasternak Foundations, Obanishola Sadiq, Gbeminiyi Sobamowo, Saheed Salawu

Karbala International Journal of Modern Science

Dynamic behaviour of free vibration of rectangular plate is investigated. This study considered an analytical approach to investigation of free vibration of thin rectangular plate immersed in fluid, resting on Winkler and Pasternak foundations.The governing nonlinear partial differential equation is analyzed using two-dimensional differential transform method. The accuracy of the analytical solutions obtained is verified with existing results in literature and confirmed in excellent agreement. Thereafter, the analytical solutions are used for investigation of effect of elastic foundation, fluid and aspect ratio on vibrating plate.From the result, it is observed that, increase elastic foundation parameters increases natural frequency ...


Crash Safety In The Introductory Physics Lab, Daniel Ludwigsen, Janet Brelin-Fornari, Joseph Neal 2019 Kettering University

Crash Safety In The Introductory Physics Lab, Daniel Ludwigsen, Janet Brelin-Fornari, Joseph Neal

Daniel Ludwigsen

Crash Safety in the Introductory Physics Lab Abstract In the field of vehicle occupant protection and crash safety, the Deceleration Sled offers researchers a controlled, repeatable, and relatively cost-effective means to test interior parts such as safety restraint systems. The sled can accelerate a 2000 lb payload to achieve a speed of 40 mph before a hydraulically controlled deceleration models the deformation of the vehicle structure during a crash. Understanding the dynamics of the sled and interpreting test results incorporates many of the core concepts of a first course in introductory physics. This application of physics principles is the inspiration ...


Developing A Workflow To Integrate Tree Inventory Data Into Urban Energy Models, Farzad Hashemi, Breanna L. Marmur, Ulrike Passe, Janette R. Thompson 2019 Iowa State University

Developing A Workflow To Integrate Tree Inventory Data Into Urban Energy Models, Farzad Hashemi, Breanna L. Marmur, Ulrike Passe, Janette R. Thompson

Ulrike Passe

Building energy simulation is of considerable interest and benefit for architects, engineers, and urban planners. Only recently has it become possible to develop integrated energy models for clusters of buildings in urban areas. Simulating energy consumption of the built environment on a relatively large scale (e.g., such as a neighborhood) will be necessary to obtain more reliable results, since building energy parameters are influenced by characteristics of the nearby environment. Therefore, the construction of a 3-D model of urban built areas with detail of the near-building environment should enhance simulation approaches and provide more accurate results. This paper describes ...


The Use Of Sacrificial Support Structures In A Rapid Machining Process, Wutthigrai Boonsuk, Matthew C. Frank 2019 Iowa State University

The Use Of Sacrificial Support Structures In A Rapid Machining Process, Wutthigrai Boonsuk, Matthew C. Frank

Wutthigrai Boonsuk

Rapid prototyping techniques for CNC machining have been developed in an effort to produce functional prototypes in appropriate materials. One of the major challenges is to develop an automatic fixturing system for the part during the milling process. The current proposed method, sacrificial support fixturing, is similar to the support structures used in existing rapid processes, such as Stereolithography. During the machining process, the sacrificial supports emerge incrementally and, at the end of the process, are the only entities connecting the part to the stock material. In this paper, we propose methodologies for the design of sacrificial support structures for ...


Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson 2019 Singh Center for Nanotechnology

Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson

Protocols and Reports

The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.


The Hydrodynamics And Heat Transfer Of Impinging Jet Flow And Circular Hydraulic Jump, Yunpeng Wang 2019 The University of Western Ontario

The Hydrodynamics And Heat Transfer Of Impinging Jet Flow And Circular Hydraulic Jump, Yunpeng Wang

Electronic Thesis and Dissertation Repository

The laminar axisymmetric flow and heat transfer of a circular impinging jet and hydraulic jump on a solid surface is analyzed theoretically using boundary-layer and thin-film approaches. Liquid jet impingement features many applications such as jet rinsing, jet cooling, liquid atomization and chemical reactors. The associated hydraulic jump dramatically affects the performance of the heat and mass transfer in such applications. In the current thesis, the effects of inertia, surface tension, surface rotation, gravity and heat transfer are comprehensively explored for impinging jet flow and the formation of hydraulic jump.

The boundary-layer heights and film thickness are found to diminish ...


Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown 2019 Iowa State University

Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown

Sarah Cady

In this study, we methylated hydroxyl groups (phenolic hydroxyl: Phe-OH and aliphatic hydroxyl: Aliph-OH) in soda lignin (SL) prior to solvent liquefaction to improve storage stability of the resulting oil. We investigated two methylating reagents, dimethyl sulfate (DMS) and dimethyl carbonate (DMC), for selective Phe-OH and total hydroxyl group (Phe-OH and Aliph-OH) blocking. Samples of SL, DMS-SL, and DMC-SL were depolymerized into oils under supercritical ethanol (350 °C). Both methylated lignins produced higher amounts of oils and smaller amounts of char compared to untreated SL due to suppressed charring reactions. Oil produced from SL had relatively higher functional group contents ...


The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg 2019 Rowan University

The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg

Theses and Dissertations

Acute Myocardial Infarction (AMI) is the leading cause of worldwide death and disability, and approximately 720,000 Americans will experience an AMI in 2018. Studies have shown that rapid hypothermia therapy (<35°C) before reperfusion in patients with AMI can reduce infarct size by 37%. Localized therapeutic hypothermia has proven the potential to cool heart tissue rapidly following AMI, 3°C in 5 minutes. Using Materialise Mimics digital imaging software and the finite volume method we analyzed temperature distributions in six patient-specific left main coronary artery (LMCA) models. A mock circulatory loop was used to determine the exiting temperatures of a standard 7 Fr catheter to feed into our model with flow rates ranging from 29.2 ml/min to 68.85 ml/min. Our work showed that therapeutic hypothermia (TH) temperatures were evident at the outlets of three out of all six heart models, which varied in each left anterior descending (LAD) and left circumflex (LCX) artery depending on flowrate. Results of this study indicate that biovariability in patient-specific vascular structures significantly impacts therapeutic hypothermia (TH) treatment methods. These results indicate that further research is needed to examine more accurate physiological effects, such as pulsatile flow and vessel wall thickness. Future models will be used to provide insight to guide more efficient TH device designs and operation parameters to optimize patient outcomes following AMI.


Quantification Of Heat Flows Through Building Entrance Doors On A Winter Day, Daeho Kang 2019 CUNY New York City College of Technology

Quantification Of Heat Flows Through Building Entrance Doors On A Winter Day, Daeho Kang

Publications and Research

The current methods for the prediction of the heat flow through building entrance doors have been used for years while involved with a certain degree of uncertainty. This paper describes an experimental method that accurately quantified such heat flow. The experiment monitored local environmental parameters in a college building on a cold winter day. The results of the experiment demonstrated that the experimental method is viable to accurately estimate the heat flow throughout the entrance doors and the presence of a vestibule moderated heat losses from the conditioned area. The results will be used for validating the existing methods.


Competence Of A Spray Passive Down-Draft Evaporative Cooling (Pdec) System For Space Cooling, Daeho Kang, Richard K. Strand 2019 CUNY New York City College of Technology

Competence Of A Spray Passive Down-Draft Evaporative Cooling (Pdec) System For Space Cooling, Daeho Kang, Richard K. Strand

Publications and Research

A spray PDEC system has been relatively less considered than other passive cooling strategies as one of the viable low-energy solutions in the cooling of buildings while having a great potential in energy savings. This study is intended to evaluate the capability of a spray PDEC system for space cooling. It comprises four simulation scenarios to see the system response and influence of indoor thermal environment when a spray PDEC system is adopted as a primary cooling system in two different climates. The simulation results show that a spray PDEC system causes a substantial variation in the indoor thermal environment ...


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