Engineering Commons^™

Samplemaskinginellipsometerand The Like Systems Including Detection Of Substrate Backside Reflections, Martin M. Liphardt, James D. Welch, Corey L. Bungay, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

A system and method of preventing substrate backside reflected components in a beam of electromagnetic radiation caused to reflect from the surface of a sample in an ellipsometer or polarimeter system, involving placing a mask adjacent to the surface of the sample which allows electromagnetic radiation to access the sample over only a limited area, wherein to access the sample over only a limited area, wherein the mask can include detector elements for collecting electromagnetic radiation reflected from the sample backside.

Doe Climate Change Research Program: Strategic Plan

United States Department of Energy: Publications

Advance the forefront of climate change research to provide the nation with the scientific knowledge it needs about the effects of greenhouse gas emissions on Earth's climate and biosphere to support effective energy and environmental decision making.

Mineralogical Transformations Controlling Acid Mine Drainage Chemistry, T. Peretyazhko, John M. Zachara, J.-F. Boily, Y. Xia, P.L. Gassman, B.W. Arey, W.D. Burgos

United States Department of Energy: Publications

The role of Fe(III) minerals in controlling acid mine drainage (AMD) chemistry was studied using samples from two AMD sites [Gum Boot (GB) and Fridays-2 (FR)] located in northern Pennsylvania. Chemical extractions, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to identify and characterize Fe(III) phases. The mineralogical analysis revealed schwertmannite and goethite as the principal Fe(III) phases in the sediments. Schwertmannite particles occurred as sub-micron sized spheroids. Their transformation into goethite occurred at the GB site where poorly-crystallized goethite rich in surface-bound sulfate was initially formed. In contrast, no schwertmannite transformation occurred …

Electrical Properties Of Zno–Batio3–Zno Heterostructures With Asymmetric Interface Charge Distribution, V. M. Voora, Tino Hofmann, M. Brandt, M. Lorenz, N. Ashkenov, M. Grundmann, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

We report on capacitance-voltage, current-voltage, Sawyer–Tower, and transient current switching measurements for a ZnO–BaTiO₃–ZnO heterostructure deposited on (001) silicon by using pulsed laser deposition. The triple-layer structure reveals asymmetric capacitance- and current-voltage hysteresis and cycling-voltage dependent Sawyer–Tower polarization drift. We explain our findings by coupling of the ferroelectric (BaTiO₃) and piezoelectric (ZnO) interface charges and parallel polarization orientation of the ZnO layers causing asymmetric space charge region formation under positive and negative bias. The transient current characteristics suggest use of this structure as nonvolatile memory device.

Managing Livestock Manure To Protect Environmental Quality, Brian L. Benham, Richard B. Ferguson, Christopher G. Henry, Michael A. Reynolds, Charles A. Shapiro, James P. Stack, Charles S. Wortmann

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Proper utilization of livestock manure is a major environmental concern. Livestock manure has typically been considered a ‘waste product’ of livestock production. A more accurate name for this material is a ‘recycled resource’ from the production of livestock. By managing livestock manure, the producer has a second chance to utilize the nutrients that have already been paid for but not fully utilized by the animal. Collecting, containing, and properly spreading livestock manure will incur additional costs for the producer. However, these costs can be offset or justified by the producer in terms of the yield enhancement and nutrient credits that …

Integrated Capture And Spectroscopic Detection Of Viruses, Crystal A. Vargas, Allison A. Wilhelm, Jeremy Williams, Pierre Lucas, Kelly A. Reynolds, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this work is to develop an online monitoring scheme for detection of viruses in flowing drinking water. The approach applies an electrodeposition process that is similar to the use of charged membrane filters previously employed for collection of viruses from aqueous samples. In the present approach, charged materials are driven onto a robust optical sensing element which has high transparency to infrared light. A spectroscopic measurement is performed using the evanescent wave that penetrates no more than 1 m from the surface of an infrared optical element in an attenuated total reflectance measurement scheme. The infrared measurement …

Rubric For Project Self-Evaluation, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

I have developed this rubric to allow each member of a project team to offer a self-assessment of their own performance on the projects. It is my attempt to develop a standardized evaluation linked to specified criteria, making the grading process simpler and more transparent.

Ruberic For Project Team Member Evaluation, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

I have developed this rubric to allow team members for course projects to offer an evaluation or assessment of the fellow members of their team. It is my attempt to develop a standardized evaluation linked to specified criteria, making the grading process simpler and more transparent.

Thin Films Formed By Selenization Of CuinXB1−X Precursors In Se Vapor, C. A. Kamler, Rodney J. Soukup, Natale J. Ianno, J. L. Huguenin-Love, J. Olejníček, S. A. Darveau, C. L. Exstrom

Department of Electrical and Computer Engineering: Faculty Publications

Previous attempts in producing light absorbing materials with bandgaps near the 1.37 eV efficiency optimum have included the partial substitution of gallium or aluminum for indium in the CIS system. The most efficient of these solar cells to date have had absorber layers with bandgaps < 1.2 eV. It is logical that an even smaller substitutional atom, boron, should lead to a wider bandgap with a smaller degree of atomic substitution. In this study, copper–indium–boron precursor films are sputtered onto molybdenum coated glass substrates and post-selenized. In the selenized films, although X-ray diffraction (XRD) measurements confirm that a CIS phase is present, Auger electron spectroscopy (AES) results indicate that boron is no longer homogeneously dispersed throughout the film as it was in the case of the unselenized precursor.

Magnitude And Variability In Emissions Savings In The Corn-Ethanol Life Cycle From Feeding Co-Products To Livestock, Virgil R. Bremer, Adam Liska, Terry J. Klopfenstein, Galen E. Erickson, Haishun Yang, Daniel T. Walters, Kenneth G. Cassman

Adam Liska Papers

Conclusions

• Co-product GHG emissions credit varied by >2-fold, from 11.5 to 28.3 gCO₂e per MJ of ethanol produced

• Co-product GHG emissions credit depend on
-types of co-products produced
-proportion fed to beef cattle vs. diary or swine
-location of corn production; the CP credit is highest in regions where GHG kg^-1grain are highest

• Depending on CP production types and feeding livestock classes, corn-ethanol net life cycle GHG intensity is 44-56 gCO₂e per MJ

• Midwest corn-ethanol reduces GHG emissions compared to gasoline by 47% on average, with co-products offsetting 23% of …

Rapidly Solidified Sm–Co–V Nanocomposite Permanent Magnets, R. S. K. Valiveti, A. Ingmire, Jeffrey E. Shield

Nebraska Center for Materials and Nanoscience: Faculty Publications

Alloys around the Sm–Co eutectic composition provide an opportunity to form two-phase nanocomposite permanent magnets consisting of nanoscale Co fibers embedded in Sm₂Co₁₇.While ternary alloying elements may refine the scale of the structure, they may also disrupt the eutectic growth and lead to the formation of primary Co. Thus, microstructural selection maps were constructed for conventionally solidified Sm–Co–V alloys. It was found that V additions enlarged the primary Sm₂Co₁₇-forming region and, at (Sm_0.09Co_0.91)₉₇ V₃, resulted in a eutectic structure. Upon rapid solidification, this alloy was …

Free Electron Behavior In Inn: On The Role Of Dislocations And Surface Electron Accumulation, V. Darakchieva, Tino Hofmann, Mathias Schubert, B. E. Sernelius, B. Monemar, P. O. A. Persson, F. Giuliani, E. Alves, H. Lu, W. J. Schaff

Nebraska Center for Materials and Nanoscience: Faculty Publications

The free electron behavior in InN is studied on the basis of decoupled bulk and surface accumulation electron densities in InN films measured by contactless optical Hall effect. It is shown that the variation in the bulk electron density with film thickness does not follow the models of free electrons generated by dislocation-associated nitrogen vacancies. This finding, further supported by transmission electron microscopy results, indicates the existence of a different thickness-dependent doping mechanism. Furthermore, we observe a noticeable dependence of the surface electron density on the bulk density, which can be exploited for tuning the surface charge in future InN …

Hole Diffusion Profile In A P-P+ Silicon Homojunction Determined By Terahertz And Midinfrared Spectroscopic Ellipsometry, Tino Hofmann, C. M. Herzinger, T. E. Tiwald, John A. Woollam, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

The noncontact and nondestructive optical determination of spatial distributions of free-charge-carriers in low-doped semiconductor homo- and heterojunctions addresses fundamental physical properties of device related structures. For low-density free-charge-carriers, particularly for hole densities with their intrinsically lower mobility parameters than electron densities, optical characterization is a challenge. The carrier density plasma frequencies are located at long wavelength equivalents within the terahertz spectral region.

Resistive Hysteresis And Interface Charge Coupling In Batio3-Zno Heterostructures, V. M. Voora, Tino Hofmann, M. Brandt, M. Lorenz, M. Grundmann, N. Ashkenov, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

We report on temperature, time, and voltage dependent resistive hysteresis measurements of BaTiO₃-ZnO heterostructures grown on (001) Si substrates by pulsed laser deposition. We observe a diodelike behavior and cycling-voltage dependent hysteresis formation under forward bias. We explain these effects with depletion layer formation between the ZnO and BaTiO₃ layers, an additional barrier due to the spontaneous polarization of ZnO and the ferroelectric nature of BaTiO₃. The disappearance of the resistive hysteresis above the ferroelectric-paraelectric phase transition temperature of BaTiO₃ conformed that the hysteresis is related to the ferroelectricity of BaTiO₃. Time …

Computational Model For Predicting Nonlinear Viscoelastic Damage Evolution In Materials Subjected To Dynamic Loading, Flavio V. Souza, Yong-Rak Kim, George A. Gazonas, David H. Allen

Department of Mechanical and Materials Engineering: Faculty Publications

Many inelastic solids accumulate numerous cracks before failure due to impact loading, thus rendering any exact solution of the IBVP untenable. It is therefore useful to construct computational models that can accurately predict the evolution of damage during actual impact/dynamic events in order to develop design tools for assessing performance characteristics. This paper presents a computational model for predicting the evolution of cracking in structures subjected to dynamic loading. Fracture is modeled via a nonlinear viscoelastic cohesive zone model. Two example problems are shown: one for model validation through comparison with a one-dimensional analytical solution for dynamic viscoelastic debonding, and …

Development Of Novel Microwave Cooking Model For Not-Ready-To Eat Foods, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Recently safety of microwave cooked food has come under scrutiny because of recent outbreak and recalls associated with some of these not-ready-to-eat (NRTE) frozen foods. Heating uniformity of these foods is paramount in rendering the foods safe for consumption. Degree of uneven microwave heating is influenced by both microwave oven and characteristics of food load which decides the electric field distribution within the food load. Given the complexity of parameters, a computer model is always desirable to optimize heating uniformity by proper selection of food shape, proportions, plating, packaging selection and more. Earlier many researchers have made one or more …

Process Simulation Of Dilute Acid Pretreatment Of Coastal Bermudagrass For Bioethanol Production, Arthur Redding, Deepak R. Keshwani, Jay J. Cheng

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Coastal bermudagrass is a promising lignocellulosic feedstock for bioethanol production. It is well suited for the Southeastern United States where it is currently grown for hay production and nutrient management in animal farming operations. Prior experiments have generated sugar and sugar degradation data from the dilute acid pretreatment and enzymatic hydrolysis of bermudagrass over a range of pretreatment conditions. Experimentally, the yield of total glucose and xylose was maximized at 93 % of the theoretical value for the pretreatment conditions 140 °C and 1.2 % sulfuric acid (w/w) for a residence time of 30 minutes. To explore further potential optimum …

Test 1952: John Deere 7330 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S712 Challenger Mt455b, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S705 Massey Ferguson 5455, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S744 Massey Ferguson 8660 Iegr, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S746 Massey Ferguson 8680 Iegr, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary S709: Massey Ferguson 5475, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Effects Of Aggregate Structure On Hot-Mix Asphalt Rutting Performance In Low Traffic Volume Local Pavements, Yong-Rak Kim, Hee Mun Park, Francisco Thiago Sacramento Aragão, Jamilla Emi Sudo Lutif

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this study is to evaluate the effect of mix gradations associated with the Superpave restricted zone on rutting potential specifically for low traffic volume roadways. Although the elim-ination of the restricted zone requirement in Superpave mix design is highly recommended, some questions still remain unanswered as the research conclusions supporting the elimination of the re-stricted zone were largely made for medium to high traffic volume roadways, where aggregates are highly crushed and of good quality. The applicability of such research conclusions based on high traffic volume mixes needs to be verified for low volume mixes because many …

Farming Systems Education: Case Study Of Swedish Test Pilots, Lennart Salomonsson, Anna Nilsson, Sofia Palmer, Adam Roigart, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

We describe and analyze a pedagogical experiment that introduced a broad and holistic perspective on complete farming systems, systemic learning tools, and a participatory learning strategy at an early stage in agronomy education. The paper describes the adventure of three students, who came from a conventional agronomy program at the Swedish University of Agricultural Sciences (SLU), who were frustrated with the lack of integrated approaches to the study of agricultural systems and a strong focus on molecular-level processes in their first year of education. They encountered a narrow focus in most courses and the overall curricula of agricultural education that …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2009, 129th Anniversary Year, One Hundred-Nineteenth Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Collegiate Academy: Biology

Earth Science

Collegiate Academy: Chemistry and Physics

Biological and Medical Sciences

Nebraska Wesleyan University Health and Sciences Graduate School Fair

Junior Academy: Senior High Competition

Aeronautics and Space Science, Poster Session

History and Philosophy of Science

Teaching of Science and Math

Maiben Memorial Lecture: Donald Frey, Department of Family Practice, Creighton University Medical Center

Anthropology

Chemistry and Physics

Junior Academy, Junior High Competition

Test 1950 John Deere 6130d Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Feynman’S Relativistic Electrodynamics Paradox And The Aharonov-Bohm Effect, Adam Caprez, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

An analysis is done of a relativistic paradox posed in the Feynman Lectures of Physics involving two interacting charges. The physical system presented is compared with similar systems that also lead to relativistic paradoxes. The momentum conservation problem for these systems is presented. The relation between the presented analysis and the ongoing debates on momentum conservation in the Aharonov-Bohm problem is discussed.

Steel Box System Monitoring Of N-2 Over I-80 Bridge, Atorod Azizinamini

Mid-America Transportation Center: Final Reports and Technical Briefs

The previously performed market analysis of bridge material in the range of short to medium span length indicates a declining trend for steel girders during the last two decades. The “simple for dead, continuous for live load” is a new method of bridge construction aiming at reducing the steel girder construction expenses and in essence enhancing the steel girders’ competitiveness in the short to medium span length bridges. This method of construction takes the advantage of the simple span construction as well as reduction of the forces in the bridge elements due to the continuous span behavior. The continuity of …

Moisture Sensitivity Of Hot Mix Asphalt (Hma) Mixtures In Nebraska – Phase Ii, Yong-Rak Kim, Hoki Ban, Ingryd Pinto

Mid-America Transportation Center: Final Reports and Technical Briefs

As a consequential effort to the previous NDOR research project (P564) on moisture damage, this report presents outcomes from this project incorporated with the previous project. Performance changes and fundamental material characteristics associated with moisture damage due to various anti-stripping additives in asphalt mixtures are studied through various experimental approaches and a numerical simulation. Three additives (i.e., one reference additive, hydrated lime, and two alternative additives: fly ash and cement) are investigated by adding them into two types of mixes (SP2 for low-traffic-volume roadways and SP5 for high-traffic-volume roadways) where two different asphalt binders (PG 64-22 for the SP2 mix …