Dynamic Monitoring and Life Prediction of Internal Strain-Gage Balances

Wind tunnel test customers continue to push the limits by producing air vehicle designs that produce high aerodynamic loads at the desired test conditions. These loads are a combination of steady aerodynamic, unsteady aerodynamic, and inertial forces. A methodology to monitor the health of a wind tunnel strain-gage balance has been developed. The objective of this methodology is to define the stress limits of the balance and monitor these limits so the balance can be safely tested without failure of the balance. A balance failure could result in costly damage to the wind tunnel model, support system, and the wind tunnel facility itself. The health monitoring method incorporates elements of signal processing, finite element analysis (FEA), cycle counting in fatigue analysis, and cumulative damage model theory. From these areas a new balance monitoring methodology that is capable of computing balance loads and stresses, factors of safety, counting fatigue cycles, and providing guidance for inspection of the balance. An example of implementation of this methodology using dynamic balance readings collected from a wind tunnel test is discussed. Results show a maximum load calculation error reduction of 71% and an overall accuracy of at least 95%. Additionally, the new methodology identified 17% more exceedances than the legacy method

The Economic Value of Biochar in Crop Production and Carbon Sequestration

This paper estimates the economic value of biochar application on agricultural cropland for carbon sequestration and its soil amendment properties. In particular, we consider the carbon emissions avoided when biochar is applied to agricultural soil, instead of agricultural lime, the amount of carbon sequestered, and the value of carbon offsets, assuming there is an established carbon trading mechanism for biochar soil application. We use winter wheat production in Eastern Whitman County, Washington as a case study, and consider different carbon offset price scenarios and different prices of biochar to estimate a farm profit. Our findings suggest that it may be profitable to apply biochar as a soil amendment under some conditions if the biochar market price is low enough and/or a carbon offset market exists.Biochar, Carbon sequestration, Crop, Farm profitability, Soil amendment

EMPLOYER SIZE, HUMAN CAPITAL, AND RURAL WAGES: IMPLICATIONS FOR SOUTHERN RURAL DEVELOPMENT

A recent trend in rural development policy emphasizes small business development in place of industrial recruitment. To analyze some of the likely effects of expanding the proportion of small firms in local economies, an empirical wage rate model incorporating employer size was developed, and parameters were estimated using household date from rural Putnam County, Georgia. The estimates indicated that large employers offered higher wages than small employers and that the wage premium they offered was greater for blacks than for whites. These results support Thomas Till's argument that southern rural counties with relatively large black populations should not abandon efforts to attract large employers. Other factors associated with higher wages included level of education, previous labor force experience, and employment in certain occupations and industries.Community/Rural/Urban Development, Labor and Human Capital,

Contracting Out Government Procurement Functions: An Analysis

Proceedings Paper (for Acquisition Research Program)The Deputy Assistant Secretary of the Navy for Research, Development & Acquisition (DASN (RDA) (Acquisition Management)), asked the Naval Postgraduate School (NPS) to analyze the contracting out of procurement functions currently being accomplished by Navy, Marine Corps, and other Department of Defense (DOD) Activities. The request specifically focused on assessing the degree of effectiveness and shortcomings of such contracting out efforts. This research sought to answer these questions: Which contracting functions are now being contracted out by Navy and other DOD organizations? How effectively have contractors performed on these contracts? What metrics are being used and could be used to assess the quality of contractor performance? Although the primary focus of this study is the effectiveness of contracts used to procure contracting services, several interrelated subjects have been explored. Aspects of inherently governmental functions, personal service relationships, conflicts of interest, and legal/ethical issues were included. Further, questions regarding the impact on the contracting system, the development of Contracting Officers, the participation of competing companies in the marketplace, training and experience qualifications, and agency procurement decision-making and policies were also examined.Naval Postgraduate School Acquisition Research ProgramApproved for public release; distribution is unlimited

Economic tradeoff between biochar and bio-oil production via pyrolysis

This paper examines some of the economic tradeoffs in the joint production of biochar and bio-oil from cellulosic biomass. The pyrolysis process can be performed with different final temperatures, and with different heating rates. While most carbonization technologies operating at low heating rates result in higher yields of charcoal, fast pyrolysis is the technology of choice to produce bio-oils. Varying operational and design parameters can change the relative quantity and quality of biochar and bio-oil produced for a given feedstock. These changes in quantity and quality of both products affect the potential revenue from their production and sale. We estimate quadratic production functions for biochar and bio-oil. The results are then used to calculate a product transformation curve that characterizes the yields of bio-oil and biochar that can be produced for a given amount of feedstock, movement along the curve corresponds to changes in temperatures, and it can be used to infer optimal pyrolysis temperature settings for a given ratio of biochar and bio-oil prices.biochar, bio-oil, pyrolysis, biomass conversion, economic tradeoff

PRIOR REGULATION AND POST LIABILITY AS COMPLEMENTS: AN APPLICATION TO PRESCRIBED BURNING LAW IN THE UNITED STATES

Prescribed burning is increasingly being recognized as a useful land management and conservation tool, but with it comes the risk of fire and smoke damage to the property of others. All but two states have codified laws specifying criminal penalties or liability rules for prescribed burning, but the laws in a number of states have changed in recent years or are under review. We develop an economic model of the incentive and welfare effects of prescribed burning and the use of prior regulation and post liability as instruments to address potential external damage from the use of prescribed fire.Resource /Energy Economics and Policy,

Method and system for providing autonomous control of a platform

The present application provides a system for enabling instrument placement from distances on the order of five meters, for example, and increases accuracy of the instrument placement relative to visually-specified targets. The system provides precision control of a mobile base of a rover and onboard manipulators (e.g., robotic arms) relative to a visually-specified target using one or more sets of cameras. The system automatically compensates for wheel slippage and kinematic inaccuracy ensuring accurate placement (on the order of 2 mm, for example) of the instrument relative to the target. The system provides the ability for autonomous instrument placement by controlling both the base of the rover and the onboard manipulator using a single set of cameras. To extend the distance from which the placement can be completed to nearly five meters, target information may be transferred from navigation cameras (used for long-range) to front hazard cameras (used for positioning the manipulator)

Renal endothelial dysfunction in acute kidney ischemia reperfusion injury

Acute kidney injury is associated with alterations in vascular tone that contribute to an overall reduction in GFR. Studies in animal models indicate that ischemia triggers alterations in endothelial function that contribute significantly to the overall degree and severity of a kidney injury. Putative mediators of vasoconstriction that may contribute to the initial loss of renal blood flow and GFR are highlighted. In addition, there is discussion of how intrinsic damage to the endothelium impairs homeostatic responses in vascular tone as well as promotes leukocyte adhesion and exacerbating the reduction in renal blood flow. The timing of potential therapies in animal models as they relate to the evolution of AKI, as well as the limitations of such approaches in the clinical setting are discussed. Finally, we discuss how acute kidney injury induces permanent alterations in renal vascular structure. We posit that the cause of the sustained impairment in kidney capillary density results from impaired endothelial growth responses and suggest that this limitation is a primary contributing feature underlying progression of chronic kidney disease

Cofilin Activation in Peripheral CD4 T Cells of HIV-1 Infected Patients: A Pilot Study

Cofilin is an actin-depolymerizing factor that regulates actin dynamics critical for T cell migration and T cell activation. In unstimulated resting CD4 T cells, cofilin exists largely as a phosphorylated inactive form. Previously, we demonstrated that during HIV-1 infection of resting CD4 T cells, the viral envelope-CXCR4 signaling activates cofilin to overcome the static cortical actin restriction. In this pilot study, we have extended this in vitro observation and examined cofilin phosphorylation in resting CD4 T cells purified from the peripheral blood of HIV-1-infected patients. Here, we report that the resting T cells from infected patients carry significantly higher levels of active cofilin, suggesting that these resting cells have been primed in vivo in cofilin activity to facilitate HIV-1 infection. HIV-1-mediated aberrant activation of cofilin may also lead to abnormalities in T cell migration and activation that could contribute to viral pathogenesis.Department of Defense (National Defense Science and Engineering Fellowship); National Institute of Allergy and Infectious Diseases (AI069981

Angle-Resolved Photoemission of Solvated Electrons in Sodium-Doped Clusters

Angle-resolved photoelectron spectroscopy of the unpaired electron in sodium-doped water, methanol, ammonia, and dimethyl ether clusters is presented. The experimental observations and the complementary calculations are consistent with surface electrons for the cluster size range studied. Evidence against internally solvated electrons is provided by the photoelectron angular distribution. The trends in the ionization energies seem mainly determined by the degree of hydrogen bonding in the solvent and the solvation of the ion core. The onset ionization energies of water and methanol clusters do not level off at small cluster sizes, but decrease slightly with increasing cluster size