An Analysis of Sportsman Activity Data Collection Methods for North Dakota

Resource /Energy Economics and Policy,

A REVIEW AND AN ANNOTATED BIBLIOGRAPHY OF STUDIES OF SOIL CONSERVATION PROGRAMS, PRACTICES AND STRATEGIES

This paper provides a brief synthesis of articles, papers and studies concerned with soil conservation programs, practices and strategies and their effects on income and water quality. The emphasis is on publications during the 1970's to help bring researchers up to date on some of the current literature.Land Economics/Use,

AGRICULTURAL LAND DRAINAGE COSTS AND RETURNS IN MINNESOTA

The objectives of this study are to (1) introduce some of the topics relative to on-farm drainage decisions in rural Minnesota, (2) briefly describe on-farm drainage methods, (3) estimate the current costs of constructing on-farm drains, (4) estimate the returns to agricultural land drainage, and (5) examine the economic feasibility of on-farm drainage in Minnesota.Land Economics/Use,

Transformational Solar Array Option I Final Report

This report summarizes the work performed under NASA contract NNC16CA19C from May 2, 2017 through April 2, 2018. This work is directed toward meeting the goals of the associated NASA NRA and, of course, the requirements of the contract. In brief, the goals are: (1) Over 47% beginning of life cell efficiency at 5 AU and -125 C (2) Over 32% end of life efficiency at the blanket level at 50 W m-2, -125 C and 4E15 1 MeV e cm-2 (3) Over 8 W kg-1 at EOL for the entire array including structure, deployment, and pointing mechanisms using beginning of life performance. (4) A stowed packaging density of greater than 66 kW m-3 (5) An ability to survive launch and numerous deploy retract cycles without degradation (6) An output higher than 300 V (7) An ability to operate in a plasma generated by xenon thrusters, typically 1E8 cm-3 ions with an average energy of 2 eV (8) A design compatible with electrostatic and magnetic cleanliness (9) Record breaking inverted metamorphic (IMM) 6 junction solar cells (10) IMM solar cells that have no anomalous flat spot behavior at low irradiance and low temperature (11) A mock-up production line for the low-cost manufacture of spacecraft blanket arrays. The Option I phase of the project continued efforts, started in the base-phase, to eliminate or reduce to very low levels the flat spots that reduce power to an unacceptable value in a significant percentage of cells and to reduce outgassing contamination of the concentrators to acceptable levels. Option I adds tasks to increase the efficiency of IMM cells from those produced in the Base Phase, to eliminate delamination of the coatings that were present in previous versions of the concentrator mirrors, to evaluate pressure sensitive adhesive as a method of fixing solar cell assemblies to blankets, to design a magnetically clean brake for ROSA, to test the robustness of a sample blanket in deploy and retract, to test for the adequate performance of a blanket in vibration and thermal environments, and to define the capital equipment needed to optimize production of the Transformational Array. 5 Work for this Final Report showed that the greatest likely improvement in the solar cells would be by emphasizing the effort for the IMM4 solar cells and stopping work on other IMM cells. For this phase, the solar cell work was primarily on the IMM4 cells with little work on IMM5 and none on IMM6 cells

Solar Arrays for Low-Irradiance Low-Temperature and High-Radiation Environments

This is the Base Period final report DRAFT for the JPL task 'Solar Arrays for Low-Irradiance Low-Temperature and High-Radiation Environments', under Task Plan 77-16518 TA # 21, for NASA's Extreme Environments Solar Power (EESP) project. This report covers the Base period of performance, 7/18/2016 through 5/2/2017.The goal of this project is to develop an ultra-high efficiency lightweight scalable solar array technology for low irradiance, low temperature and high-radiation (LILT/Rad) environments. The benefit this technology will bring to flight systems is a greater than 20 reduction in solar array surface area, and a six-fold reduction in solar array mass and volume. The EESP project objectives are summarized in the 'NRA Goal' column of Table 1. Throughout this report, low irradiance low temperature (LILT) refers to 5AU -125 C test conditions; beginning of life (BOL) refers to the cell state prior to radiation exposure; and end of life (EOL) refers to the test article condition after exposure to a radiation dose of 4e15 1MeV e(-)/cm(exp 2)

Book Review: American Shoes - A Refugee’s Story

A review of the book American Shoes: A Refugee’s Story, a memoir of a German girl’s journey as a refugee in Nazi Germany as told through her nightmares during her journey back to America

Book review: Everything Sad Is Untrue

A review of the book “Everything Sad is Untrue (A True Story), by Daniel Nayeri, is presented

Using Unsupervised Machine Learning to Reduce the Energy Requirements of Active Flow Control

It is generally accepted that there exist two types of laminar separation bubbles (LSBs): short and long. The process by which a short LSB transitions to a long LSB is known as bursting. In this research, large eddy simulations (LES) are used to study the evolution of an LSB that develops along the suction surface of the L3FHW-LS at low Reynolds numbers. The L3FHW-LS is a new high-lift, high-work low-pressure turbine (LPT) blade designed at the Air Force Research Laboratory. The LSB is shown to burst over a critical range of Reynolds numbers. Bursting is discussed at length and its effect on transition, vortex shedding, and profile loss development are analyzed in depth. The results of these analyses make one point very clear: the effects of bursting are non-trivial. That is, long LSBs are not just longer versions of short LSBs. They are phenomena unto themselves, distinct from short LSBs in terms of their vortex dynamics, profile loss footprint, time-averaged topology, etc. This work culminates in a demonstration of how, with the aid of unsupervised machine learning, these differences can be leveraged to reduce the energy requirements of steady vortex generator jets (VGJs). Relative to pulsed VGJs, steady VGJs require significantly more energy to be effective but are more realistic to implement in actual application. By tailoring VGJ actuation to LSB type (i.e., actuating differently in response to a long LSB than to a short LSB), it is shown that significant energy savings can be realized

Investigation of Spalart-Allmaras Turbulence Model for Vortex Flows

Conventional turbulence models often predict behaviors opposite as to what is observed in flows subject to rotation. In this type of flow scenario, rotation typically induces turbulence suppression. To address this limitation, a modification to the Spalart Allmaras Model with Rotation Correction (SA-R) was proposed to enhance the original Spalart Allmaras Model’s sensitivity to rotation and curvature. To test the validity and accuracy of this modification, two cases were investigated. The first case involved an axisymmetric rotating pipe. A Reynolds Number of 37,000 was implemented and the initial and boundary conditions established by Zaets et. al. were utilized. Initially non-rotating, the flow transitioned to full rotation at N=0.6 at 9 m. Results demonstrated strong alignment with experimental data, showcasing improvements over the SA , SA-R, SARC, and SA-R23 models. In the second case, a vortex, surrounded by irrotational flow, was studied. This case used a Reynolds number of 10^5, and implemented the initial and boundary conditions outlined by Spalart and Garbaruk. While the modified model showed improvement over the SA model, it still displayed slight circulation overshoot, a behavior considered unphysical. However, it notably reduced the magnitude of eddy viscosity. The SARC model did produce a laminar state solution. Other vortex parameters also indicated circulation overshoot of the modified SA-R model. Overall, the modified SA-R model showed significant improvement for rotational flow scenarios and holds potential for further refinement to improve accuracy

Comparing the Iowa and Soochow Gambling Tasks in Opiate Users

The Iowa Gambling Task (IGT) is in many respects the gold standard for demonstrating decision making in drug using groups. However, it is not clear how basic task properties such as the frequency and magnitude of rewards and losses affect choice behavior in drug users and even in healthy players. In this study, we used a variant of the IGT, the Soochow Gambling Task (SGT), to observe choice behavior in opiate users and healthy decision makers in a task where reward frequency is not confounded with the long-term outcome of each alternative. In both opiate users (n = 26) and healthy controls (n = 27), we show that reward frequency strongly influences choice behavior in the IGT and SGT. Neither group showed a consistent preference across tasks for alternatives with good long-term outcomes, but rather, subjects appeared to prefer alternatives that win most frequently. We interpret this as evidence to suggest that healthy players perform better than opiate users on the IGT because they are able to utilize gain–loss frequencies to guide their choice behavior on the task. This challenges the previous notion that poorer performance on the IGT in drug users is due to an inability to be guided by future consequences