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2016

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Articles 6631 - 6660 of 9606

Full-Text Articles in Engineering

Finite Element Modeling Of Shallow Embedded Connection Stiffness, Trevor Jones, Dr. Paul Richards Jan 2016

Finite Element Modeling Of Shallow Embedded Connection Stiffness, Trevor Jones, Dr. Paul Richards

Journal of Undergraduate Research

Shallowly embedded connections are a common and important connection of steel columns to reinforced concrete foundations, which can increase the building’s overall stiffness and strength. Until now, their contributions have been neglected because they are hard to quantify and study. Previous research at BYU (Barnwell 2015) has shown that the strength and stiffness available in these connections is greater than was previously assumed. A thorough understanding of these desirable properties would allow engineers to design buildings that are more cost-effective.


Development Of Pvdf Membrane Nanocomposites Via Various Functionalization Approaches For Environmental Applications, Douglas M. Davenport, Minghui Gui, Lindell E. Ormsbee, Dibakar Bhattacharyya Jan 2016

Development Of Pvdf Membrane Nanocomposites Via Various Functionalization Approaches For Environmental Applications, Douglas M. Davenport, Minghui Gui, Lindell E. Ormsbee, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

Membranes are finding wide applications in various fields spanning biological, water, and energy areas. Synthesis of membranes to provide tunable flux, metal sorption, and catalysis has been done through pore functionalization of microfiltration (MF) type membranes with responsive behavior. This methodology provides an opportunity to improve synthetic membrane performance via polymer fabrication and surface modification. By optimizing the polymer coagulation conditions in phase inversion fabrication, spongy polyvinylidene fluoride (PVDF) membranes with high porosity and large internal pore volume were created in lab and full scale. This robust membrane shows a promising mechanical strength as well as high capacity for loading …


Free And Open-Source Control Software For 3-D Motion And Processing, Bas Wijnen, G. C. Anzalone, Amberlee S. Haselhuhn, Paul G. Sanders, Joshua M. Pearce Jan 2016

Free And Open-Source Control Software For 3-D Motion And Processing, Bas Wijnen, G. C. Anzalone, Amberlee S. Haselhuhn, Paul G. Sanders, Joshua M. Pearce

Department of Materials Science and Engineering Publications

RepRap 3-D printers and their derivatives using conventional firmware are limited by: 1) requiring technical knowledge, 2) poor resilience with unreliable hardware, and 3) poor integration in complicated systems. In this paper, a new control system called Franklin, for CNC machines in general and 3-D printers specifically, is presented that enables web-based three dimensional control of additive, subtractive and analytical tools from any Internet connected device. Franklin can be set up and controlled entirely from a web interface; it uses a custom protocol which allows it to continue printing when the connection is temporarily lost, and allows communication with scripts.


Bioenergy From Wastewater-Based Biomass, Ronald C. Sims, Sean K. Bedingfield, Reese Thompson, Judith L. Sims Jan 2016

Bioenergy From Wastewater-Based Biomass, Ronald C. Sims, Sean K. Bedingfield, Reese Thompson, Judith L. Sims

Biological Engineering Faculty Publications

The U.S. Department of Energy (DOE) has stated that biomass is the only renewable resource that can supplant petroleum-based liquid transportation fuels in the near term. Wastewater is beginning to be viewed as a potential resource that can be exploited for biomass production and conversion to bioenergy. We suggest that using wastewater from municipalities and industries as a resource for cultivating biomass and combining wastewater treatment with the production of biomass for bioenergy would provide benefits to both industries. Two waste-based biomass production systems that currently have large nationwide infrastructures include: (1) wastewater treatment systems that can be used to …


Asee Best Practices Retention, Matt Badura Jan 2016

Asee Best Practices Retention, Matt Badura

ASEE Best Practice Series Presentations

No abstract provided.


Calpoly 2015 Transportation Survey Report, William Riggs Jan 2016

Calpoly 2015 Transportation Survey Report, William Riggs

City and Regional Planning Studios and Projects

In the spring of 2015, City & Regional Planning faculty conducted a campus-wide transportation survey as part of work on the campus Climate Action Plan. The survey represented spring 2014 commutes and was issued to a sample of full and part-time CalPoly faculty, staff, students and auxiliaries with assistance from Facilities Services and the Vice President for Administration and Finance.

The total number of responses was 3,961, roughly 17% of the entire campus population of roughly 23,000. Unsurprisingly, the majority of respondents were students, totaling 68.6%, while the rest were made up of faculty, staff, and visitors. Results are significant …


Wireless Communication In Data Centers: A Survey, Abdelbaset S. Hamza, Jitender Deogun, Dennis R. Alexander Jan 2016

Wireless Communication In Data Centers: A Survey, Abdelbaset S. Hamza, Jitender Deogun, Dennis R. Alexander

School of Computing: Faculty Publications

Data centers (DCs) is becoming increasingly an integral part of the computing infrastructures of most enterprises. Therefore, the concept of DC networks (DCNs) is receiving an increased attention in the network research community. Most DCNs deployed today can be classified as wired DCNs as copper and optical fiber cables are used for intra- and inter-rack connections in the network. Despite recent advances, wired DCNs face two inevitable problems; cabling complexity and hotspots. To address these problems, recent research works suggest the incorporation of wireless communication technology into DCNs. Wireless links can be used to either augment conventional wired DCNs, or …


A Literature Review Of The Beneficial Use Of Dredged Material And Sediment Management Plans And Strategies, Portland State University. Hatfield School Of Government. Center For Public Service, Michelle Welch, Eric Thomas Mogren, Lauren Beeney Jan 2016

A Literature Review Of The Beneficial Use Of Dredged Material And Sediment Management Plans And Strategies, Portland State University. Hatfield School Of Government. Center For Public Service, Michelle Welch, Eric Thomas Mogren, Lauren Beeney

Center for Public Service Publications and Reports

This report identifies lessons learned from the body of existing literature on dredge sediment beneficial uses. It also examines the constructive role collaborative processes can play in development of sediment management plans. The authors reviewed approximately 100 documents and reports for this project. Seventeen of those were reviewed in detail based on their relevance in identifying sediment beneficial uses and/or the use of collaborative processes in the development of sediment management plans. A number of these documents were sediment management plans and strategies for specific projects and programs in other locations. The report presents findings and lessons for the consideration …


Development Of A Glucose-Powered Biobattery For Implantation And Use In Humans, Carson Sparks, Cody Maughan, Lucas Smith, Carson Sparks Jan 2016

Development Of A Glucose-Powered Biobattery For Implantation And Use In Humans, Carson Sparks, Cody Maughan, Lucas Smith, Carson Sparks

Research on Capitol Hill

With current demands for implantable electrical devices increasing, the need for a more stable and biocompatible source of power is becoming increasingly necessary. Several battery types and materials were evaluated. Ultimately, an abiotic biobattery was designed with the goal of implantation in the human body. Nafion, single-walled carbon nanotubes (SWCNTs), and gold were used to create an abiotic biobattery that is powered by glucose.

The SWCNTs were used to create the cathode, the gold was used to fabricate the anode, and the Nafion acted as the separator between the cathode and anode. A thin Nafion membrane was evaluated for overlaying …


Improved Production Of Promising Antioxidant, Resveratrol, In Escherichia Coli, Chad Skidmore Jan 2016

Improved Production Of Promising Antioxidant, Resveratrol, In Escherichia Coli, Chad Skidmore

Research on Capitol Hill

Resveratrol is a promising antioxidant natural product. Studies have shown that it is effective against heart disease, cancer, Alzheimer's disease, diabetes, and harmful UV rays. This health-benefiting molecule is present in plants such as peanuts, berries, and the skin of red grapes.

A growth time of 10 months makes Japanese knotweed an impractical source of resveratrol. A more efficient way to produce resveratrol has been found by using E. coli as tiny biological factories.


Zeta Potential: Key To Harvesting Algae For Biofuels And Bioproducts, Celeste Hancock, Michael Flores Jan 2016

Zeta Potential: Key To Harvesting Algae For Biofuels And Bioproducts, Celeste Hancock, Michael Flores

Research on Capitol Hill

  • Algae is an effective and sustainable resource for creating a broad spectrum of bioproducts.
  • Scientists have found it challenging to harvest algae due to the difficulty of collecting algae when in an aqueous solution such as wastewater.
  • Rotating Algal Biofilm Reactors (RABRs) coated with carbon nanotubes have proved effective. The RABR floats in an aqueous environment and attracts charged algal particles in suspension.
  • The tendency for algae to favor suspension over coagulation occurs only when particles of algae are sufficiently charged. This charge can be measured by analyzing the electric potential at the interface between the surface of a particle …


Beyond The Fiber: Novel Spider Silk Coatings And Adhesives, Danielle A. Gaztambide, Breton A. Day Jan 2016

Beyond The Fiber: Novel Spider Silk Coatings And Adhesives, Danielle A. Gaztambide, Breton A. Day

Research on Capitol Hill

Natural spider silks have long been recognized for their combination of incredible strength and elasticity. Spider silk is more elastic than nylon, tougher than Kevlar, and stronger than steel by weight. Due to an inability to farm spiders, much work has been done to produce spider silks in transgenic hosts for large -scale production. Our work was done using recombinant spider silk proteins produced in transgenic goats and the bacteria E. coli.

More recently spider silks have also been recognized for their biocompatibility and lack of immunogenicity. Spider silks' incredible strength and ability to be implanted safely within the body …


Dr. Regan Zane Presenting At 2016 Ite Annual Conference | Utah State University Power Electronics Lab, Usu College Of Engineering Jan 2016

Dr. Regan Zane Presenting At 2016 Ite Annual Conference | Utah State University Power Electronics Lab, Usu College Of Engineering

College of Engineering News

Dr. Regan Zane will be presenting at the 2016 ITE Annual Conference. The ITE conference this year will focus on issues with transportation by studying and understanding future trends. Dr. Zane will be presenting with Zach Kahn and Blake Thomas on Vehicle Electrification & Energy.


Wavelet Coherence Analysis Of Dynamic Cerebral Autoregulation In Neonatal Hypoxic–Ischemic Encephalopathy, Fenghua Tian, Takashi Tarumi, Hanli Liu, Rong Zhang, Lina Chalak Jan 2016

Wavelet Coherence Analysis Of Dynamic Cerebral Autoregulation In Neonatal Hypoxic–Ischemic Encephalopathy, Fenghua Tian, Takashi Tarumi, Hanli Liu, Rong Zhang, Lina Chalak

Bioengineering Faculty Publications - Archive

Cerebral autoregulation represents the physiological mechanisms that keep brain perfusion relatively constant in the face of changes in blood pressure and thus plays an essential role in normal brain function. This study assessed cerebral autoregulation in nine newborns with moderate-to-severe hypoxic–ischemic encephalopathy (HIE). These neonates received hypothermic therapy during the first 72 h of life while mean arterial pressure (MAP) and cerebral tissue oxygenation saturation (SctO2) were continuously recorded. Wavelet coherence analysis, which is a time-frequency domain approach, was used to characterize the dynamic relationship between spontaneous oscillations in MAP and SctO2. Wavelet-based metrics of phase, coherence and gain were …


Making Civilian Drones Safe: Performance Standards, Self-Certification, And Post-Sale Data Collection, Henry Perritt, Albert Plawinski Jan 2016

Making Civilian Drones Safe: Performance Standards, Self-Certification, And Post-Sale Data Collection, Henry Perritt, Albert Plawinski

All Faculty Scholarship

With millions of small drones in private hands, the FAA continues its struggle to develop an effective regulatory regime to comply with Congress’s mandate to integrate them into the national airspace system. Thousands of individuals and small businesses have obtained authorization from the FAA—"section 333 exemptions"—allowing them to fly their drones commercially. Farmers, TV stations, surveyors, construction-site supervisors, real estate agents, people selling their properties, and managers seeking cheaper and safer ways to inspect their facilities, want to hire the exemption holders, but many are holding back until the FAA clarifies the groundrules.The FAA understands that its traditional approach for …


College Of Engineering News, Georgia Southern University Jan 2016

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

  • Adel El Shahat in Who’s Who


Performance Metrics For Depth-Based Signal Separation Using Deep Vertical Line Arrays, Gabriel Paul Kniffin, John Kenneth Boyle, Lisa Zurk, Martin Siderius Jan 2016

Performance Metrics For Depth-Based Signal Separation Using Deep Vertical Line Arrays, Gabriel Paul Kniffin, John Kenneth Boyle, Lisa Zurk, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

A recent publication by McCargar and Zurk [(2013). J. Acoust. Soc. Am. 133(4), EL320–EL325] introduced a modified Fourier transform-based method for passive source depth estimation using vertical line arrays deployed below the critical depth in the deep ocean. This method utilizes the depth-dependent modulation caused by the interference between the direct and surface-reflected acoustic arrivals, the observation of which is enhanced by propagation through the reliable acoustic path. However, neither the performance of this method nor its limits of applicability have yet been thoroughly investigated. This paper addresses both of these issues; the first by identifying and analyzing the factors …


Relationship Between The Home Energy Score (Hes) And The Home Energy Rating System (Hers), Florida Solar Energy Center, Philip W. Fairey Jan 2016

Relationship Between The Home Energy Score (Hes) And The Home Energy Rating System (Hers), Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

A significant cohort of approximately 2,900 registered home energy ratings using the REM/Rate HERS software tool, as reported to RESNET, are subjected to statistical analysis by the Dillon Group, Inc. The statistical analysis determines the distribution of HES results as a function of home energy efficiency as measured by the minimum standards of the 2009 IECC and by EPA’s ENERGY STAR program.

In addition, a parametric simulation analysis is conducted by the Florida Solar Energy Center using EnergyGauge® USA version 5.0, a RESNET-accredited HERS software tool, to determine the relationship between HES scores and the HERS Index. The parametric analysis …


Influence Of Oxygen Concentration On The Performance Of Ultra-Thin Rf Magnetron Sputter Deposited Indium Tin Oxide Films As A Top Electrode For Photovoltaic Devices, Jephias Gwamuri, Murugesan Marikkannan, J. Mayandi, Patrick Bowen, Joshua M. Pearce Jan 2016

Influence Of Oxygen Concentration On The Performance Of Ultra-Thin Rf Magnetron Sputter Deposited Indium Tin Oxide Films As A Top Electrode For Photovoltaic Devices, Jephias Gwamuri, Murugesan Marikkannan, J. Mayandi, Patrick Bowen, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The opportunity for substantial efficiency enhancements of thin film hydrogenated amorphous silicon (a-Si:H) solar photovoltaic (PV) cells using plasmonic absorbers requires ultra-thin transparent conducting oxide top electrodes with low resistivity and high transmittances in the visible range of the electromagnetic spectrum. Fabricating ultra-thin indium tin oxide (ITO) films (sub-50 nm) using conventional methods has presented a number of challenges; however, a novel method involving chemical shaving of thicker (greater than 80 nm) RF sputter deposited high-quality ITO films has been demonstrated. This study investigates the effect of oxygen concentration on the etch rates of RF sputter deposited ITO films to …


Thermal Properties Of Natural-Colored And Darkened Portland Cement Concrete Pavement, Tenli Waters, W. Spencer Guthrie Jan 2016

Thermal Properties Of Natural-Colored And Darkened Portland Cement Concrete Pavement, Tenli Waters, W. Spencer Guthrie

Journal of Undergraduate Research

The purpose of this project was to measure thermal properties of natural-colored and darkened portland cement concrete in order to explain observations from field data already collected. While portland cement concrete pavement offers a durable surface and long service life when designed and constructed properly, selected concrete pavement sections require expensive winter maintenance treatments to clear snow and ice. One method of potentially reducing winter maintenance costs is darkening the concrete pavement. Darkening the concrete reduces its albedo, or whiteness, and should therefore promote higher pavement surface temperatures through increased absorption of radiation energy from the sun. In winter, darkened …


Girl’S Cybersecurity Camp, Sarah Cunha, Dale Rowe Jan 2016

Girl’S Cybersecurity Camp, Sarah Cunha, Dale Rowe

Journal of Undergraduate Research

In 2015, the BYU Cybersecurity Research Lab (CSRL) held its first annual summer camp for Girls aged 14-18. A total of 38 girls attended the week’s activities and workshops. While over 75% of girls indicated they had taken a computing-related class, only 40% reported any significant interest in cybersecurity prior to the summercamp with 10% believing they had some experience in the field. At the conclusion of the camp, 80% of attendees reported a significant interest in the field with 100% of attendees interested in attending a similar event again.


Multimodal, Biomaterial-Focused Anticoagulation Via Superlow Fouling Zwitterionic Functional Groups Coupled With Anti-Platelet Nitric Oxide Release, Kagya Amoako, Harihara S. Sundaram, Ahmed Suhaib, Shaoyi Jiang, Keith E. Cook Jan 2016

Multimodal, Biomaterial-Focused Anticoagulation Via Superlow Fouling Zwitterionic Functional Groups Coupled With Anti-Platelet Nitric Oxide Release, Kagya Amoako, Harihara S. Sundaram, Ahmed Suhaib, Shaoyi Jiang, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

The functions of anti-fouling, zwitterionic polycarboxybetaine (pCB) and anti-platelet nitric oxide (NO) release replicate key anticoagulant properties of the endothelium. The two approaches, only tested separately thus far, were paired on gas permeable polydimethylsiloxane (PDMS) membranes and evaluated for anti-coagulation. Uncoated PDMS (control) and PDMS coated with pCB were screened for fibrinogen (Fg) fouling followed by platelet adsorption testing to evaluate the effects of coating and/or NO using bioreactors. Bare or coated PDMS membranes separated sheep plasma (108 platelets/ml) and gas flow chambers within the bioreactors. Either 100 or 0 ppm of NO/N2 flowed through the gas chamber for NO …


Service-Learning And Engineering: Design Projects That Promote Inclusion And Independence, Matthew T. Siniawski Jan 2016

Service-Learning And Engineering: Design Projects That Promote Inclusion And Independence, Matthew T. Siniawski

Faculty Pub Night

No abstract provided.


Sustainable P2 Design For Batch-Based Specialty Chemical Manufacture, Brigitte Pastore Jan 2016

Sustainable P2 Design For Batch-Based Specialty Chemical Manufacture, Brigitte Pastore

Theses and Dissertations

A case study has been conducted on the reduction of n-methyl-2-pyrrilodone (NMP) solvent waste in the manufacture of polyimide and polybenzoxazole precursors. The evaluation includes the environmental and economic assessment of solvent recovery and substitution strategies. A two-step distillation process proved effective in recovering 95% of the NMP at a purity of 99.97% from the aqueous solvent waste stream. Yearly operating costs were reduced by 83% and total life cycle emissions were reduced by 44%, due to reduction in virgin NMP use and hazardous waste disposal. With capital acquisition, the recovery option would still result in a net present value …


Switchgrass (Panicum Virgatum) Fermentation By Clostridium Thermocellum And Clostridium Saccharoperbutylacetonicum Sequential Culture In A Continuous Flow Reactor, Noelia M. Elia, Sue E. Nokes, Michael D. Flythe Jan 2016

Switchgrass (Panicum Virgatum) Fermentation By Clostridium Thermocellum And Clostridium Saccharoperbutylacetonicum Sequential Culture In A Continuous Flow Reactor, Noelia M. Elia, Sue E. Nokes, Michael D. Flythe

Biosystems and Agricultural Engineering Faculty Publications

The study was conducted to evaluate fermentation by Clostridium thermocellum and C. saccharoperbutylacetonicum in a continuous-flow, high-solids reactor. Liquid medium was continuously flowed through switchgrass (2 mm particle size) at one of three flow rates: 83.33 mL h−1 (2 L d−1), 41.66 mL h−1 (1 L d−1), and 20.833 mL h−1 (0.5 L d−1). The cellulolytic phase was initiated by culturing C. thermocellum (63 °C, 24 h). The temperature was decreased (35) and C. saccharoperbutylacetonicum was inoculated. When metabolism decreased (96 h), the temperature was increased (63 °C; 24 h) …


High-Resolution Soil Moisture Estimation Using Ascat, Kevin Tew, Michael Scott Jan 2016

High-Resolution Soil Moisture Estimation Using Ascat, Kevin Tew, Michael Scott

Journal of Undergraduate Research

NASA’s Decadal Survey emphasizes the importance of soil moisture measurements, citing their significance in predicting natural hazards and the role of soil moisture levels in the water and carbon cycles [1]. Soil moisture estimates are used for a variety of applications including drought detection, flood and landslide forecasts, crop yield monitoring, and rain precipitation models [1]–[4]. Orbiting sensors provide an effective way to measure soil moisture globally because measurements of each area can be taken at a relatively high revisit frequency (typically one to two days). These sensors are generally able to measure soil moisture parameters despite cloud coverage and, …


Single Ion Detection For Mass Spectrometry Using Low Capacitance Mosfets, Matthew Hamblin, Aaron Hawkins Jan 2016

Single Ion Detection For Mass Spectrometry Using Low Capacitance Mosfets, Matthew Hamblin, Aaron Hawkins

Journal of Undergraduate Research

Mass spectrometry is an important tool for analytical chemistry that allows the chemical composition of a compound to be determined. In order to do so, it separates the compound into ions, and then detects the number of ions of different masses.

The charge on a single ion is very small, making it difficult to measure. In order to overcome this, current mass spectrometers must use methods such as electron multipliers to create a cascading effect of electrons until a measurable charge is reached or cryodetectors that measure the thermal change of an ion hit at low temperatures.1 Using methods …


Post-Eruption Deformation Processes Measured Using Alos-1 And Uavsar Insar At Pacaya Volcano, Guatemala, Lauren Schaefer, Zhong Lu, Thomas Oommen Jan 2016

Post-Eruption Deformation Processes Measured Using Alos-1 And Uavsar Insar At Pacaya Volcano, Guatemala, Lauren Schaefer, Zhong Lu, Thomas Oommen

Michigan Tech Publications, Part 1

Pacaya volcano is a persistently active basaltic cone complex located in the Central American Volcanic Arc in Guatemala. In May of 2010, violent Volcanic Explosivity Index-3 (VEI-3) eruptions caused significant topographic changes to the edifice, including a linear collapse feature 600 m long originating from the summit, the dispersion of ~20 cm of tephra and ash on the cone, the emplacement of a 5.4 km long lava flow, and ~3 m of co-eruptive movement of the southwest flank. For this study, Interferometric Synthetic Aperture Radar (InSAR) images (interferograms) processed from both spaceborne Advanced Land Observing Satellite-1 (ALOS-1) and aerial Uninhabited …


Life Cycle Assessment And Optimization-Based Decision Analysis Of Construction Waste Recycling For A Leed-Certified University Building, Murat Kucukvar, Gokhan Egilmez, Omer Tatari Jan 2016

Life Cycle Assessment And Optimization-Based Decision Analysis Of Construction Waste Recycling For A Leed-Certified University Building, Murat Kucukvar, Gokhan Egilmez, Omer Tatari

Mechanical and Industrial Engineering Faculty Publications

The current waste management literature lacks a comprehensive LCA of the recycling of construction materials that considers both process and supply chain-related impacts as a whole. Furthermore, an optimization-based decision support framework has not been also addressed in any work, which provides a quantifiable understanding about the potential savings and implications associated with recycling of construction materials from a life cycle perspective. The aim of this research is to present a multi-criteria optimization model, which is developed to propose economically-sound and environmentally-benign construction waste management strategies for a LEED-certified university building. First, an economic input-output-based hybrid life cycle assessment model …


Impurity Resonant States P-Type Doping In Wide-Band-Gap Nitrides, Zhiqiang Liu, Xiaoyan Yi, Zhiguo Yu, Gongdong Yuan, Yang Liu, Junxi Wang, Jinmin Li, Na Lu, Ian Ferguson, Yong Zhang Jan 2016

Impurity Resonant States P-Type Doping In Wide-Band-Gap Nitrides, Zhiqiang Liu, Xiaoyan Yi, Zhiguo Yu, Gongdong Yuan, Yang Liu, Junxi Wang, Jinmin Li, Na Lu, Ian Ferguson, Yong Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, a new strategy for achieving efficient p-type doping in high bandgap nitride semiconductors to overcome the fundamental issue of high activation energy has been proposed and investigated theoretically and demonstrated experimentally. Specifically, in an Al x Ga 1-x N/GaN superlattice structure, by modulation doping of Mg in the Al x Ga 1-x N barriers, high concentration of holes is generated throughout the material. A hole concentration as high as 1.1 x 10 18 cm -3 has been achieved, which is about one order of magnitude higher than that typically achievable by direct doping GaN. Results from first-principal …