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,

Book review: Everything Sad Is Untrue

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

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,

An Analysis of Sportsman Activity Data Collection Methods for North Dakota

Resource /Energy Economics and Policy,

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

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

Passado, Presente e Futuro: questões sobre o regime de historicidade em Étienne Pasquier na década de 1560

Resumo: Neste artigo[1] busca-se analisar as concepções de história empreendidas por Étienne Pasquier em três textos da década de 1560 na França, e a relação entre estas concepções e as ideias sobre política e religião concebidas pelo autor a fim de apontar possíveis explicações para as alterações nesta relação. Acredita-se que o primeiro e terceiro texto analisado (1560 e 1564) estão de acordo com as concepções de história relacionados com o regime de historicidade da Historia Magistra Vitae, enquanto o segundo texto (1561) rompe de maneira significativa com esta maneira de pensar a história. Ao invés de somente apontar as diferenças entre estas perspectivas históricas o presente texto procura criar uma linha argumentativa que coloca os três textos sob a mesma perspectiva, ou seja, a busca por uma maior concentração do poder político na mão da coroa Francesa.Palavras-chave: Étienne Pasquier. Paris-França. Regime de historicidade. Espaços de experiência. Horizonte de expectativas.[1] O presente artigo foi primeiramente apresentado no VII colóquio Sonho e Razão no mundo Ibérico - A crise da consciência europeia: teologia moral, razão e ocidente

Economic Analysis of Grid Level Energy Storage for the Application of Load Leveling

The benefits that exist on behalf of energy storage appear to be nearly limitless and there is no exception to this in power systems. Energy storage can be used to flatten an electrical load by charging the storage when the system load is low and discharging the storage when the system load is high. This technique is known as load leveling and is the storage application of interest in this thesis. One of the biggest benefits that load leveling can yield is the elimination of expensive gas turbine generators. Gas turbine generators are used because they can react to drastic changes in the system load that other generators can’t. Their downfall however, is that they are more expensive than the other generators. But if the load is level enough, there is no need to use gas turbine generators because there aren’t any drastic changes in the load. Load leveling requires a storage device to have a very large capacity. In this thesis several different large storage types are studied to see which ones are best suited for the application of load leveling. Ultimately both NaS batteries and pumped hydro storage are chosen to use for this study and the results for each is compared. A theoretical double peak system load with a peak value of 1950 megawatts is used for this study. The load is leveled by discretizing the energy storage’s charging and discharging profiles and allocating the stored energy by means of dynamic programming. An economic analysis of both the original case and the case in which energy storage is used to level the load is carried out. This study shows that energy storage used for the application of load leveling can be economically beneficial depending on the type of storage that is used. Battery storage is not quite ready to be used for this application but with some improvements to the technology it could be soon. Pumped storage on the other hand is the cheapest form grid level energy storage and can generate a great deal of economic gain in today’s power systems

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)

Estimation of Harmonics, InterHarmonics and Sub-Harmonics in Motor Drive Systems

Harmonic analysis in power systems is a challenge that is always evolving due to a constantly changing power grid. Advances in power electronics have led to the installation of many new non-linear power loads, such as power converters, arc furnaces and motor drive systems, which in turn change the existing infrastructure and inject new types of harmonics. This study analyzes a static Kramer drive system for its harmonic behavior. The system is broken down component-by-component and analyzed. The analysis includes classical harmonics of integer multiple of the fundamental frequency as well as sub-harmonics and interharmonics. This paper shows that there are significant harmonic issues in a static Kramer drive that are likely to be present in similar drive systems. Due to the unknown frequencies at which interharmonics and sub-harmonics arise it is difficult to estimate the magnitude and phase of these harmonics. It is proposed that state estimation techniques such as digital filtering coupled with windowing techniques can be used to properly pinpoint the frequency components, magnitudes and phases of harmonics, interharmonics and sub-harmonics in the motor drive systems. Once identified, the harmonics, interharmonics and sub-harmonics can be eliminated by means of passive filtering or self-tuning active filtering. The optimal methods of estimation of harmonics, interharmonics and sub-harmonics will be both developed analytically and through the means of simulation with the use of CAD tools such as PSCAD and MATLAB. The development of the optimal techniques for estimation of harmonics, interharmonics and sub-harmonics for that static Kramer drive will aid in estimation of harmonics, interharmonics and sub-harmonics in similar motor drive systems