The Mid-IR Spectral Effects of Darkening Agents and Porosity on the Silicate Surface Features of Airless Bodies

We systematically measured the mid-IR spectra of different mixtures of three silicates (antigorite, lizardite, and pure silica) with varying effective porosities and amounts of darkening agent (iron oxide and carbon). These spectra have broad implications for interpretation of current and future mission data for airless bodies, as well as for testing the capabilities of new instruments. Serpentines, such as antigorite and lizardite, are common to airless surfaces, and their mid-IR spectra in the presence of darkening agents and different surface porosities would be typical for those measured by spacecraft. Silica has only been measured in the plumes of Enceladus and presents exciting possibilities for other Saturn-system surfaces due to long range transport of E-ring material. Results show that the addition of the IR-transparent salt, KBr, to simulate surface porosity affected silicate spectra in ways that were not predictable from linear mixing models. The strengthening of silicate bands with increasing pore space, even when only trace amounts of KBr were added, indicates that spectral features of porous surfaces are more detectable in the mid-IR. Combining iron oxide with the pure silicates seemed to flatten most of the silicate features, but strengthened the reststrahlen band of the silica. Incorporating carbon with the silicates weakened all silicate features, but the silica bands were more resistant to being diminished, indicating silica may be more detectable in the mid-IR than the serpentines. We show how incorporating darkening agents and porosity provides a more complete explanation of the mid-IR spectral features previously reported on worlds such as Iapetus

Distributional Impact of U.S. Farm Commodity Programs: Accounting for Alternative Farm Household Typologies

Agricultural households adjust to policy changes through market mechanisms by altering: their production mix, labor input, and on- and off-farm investments. Because of the significant heterogeneity among farms in the US agricultural sector, various types of farm households respond to the same policy change in significantly different ways. The parameters used to classify farm households into different typologies may also play a significant role in the interpretation of observed effects of policy changes. This paper, using a highly disaggregated U.S. Computable General Equilibrium (CGE) model, analyzes the distributional impacts of policy changes involving price-contingent government payments on alternative U.S. farm household typologies. We find that farm households do vary their responses to an elimination of price-contingent support based on location, production specialty, and farm categorization.Agricultural and Food Policy,

Producing College, Career, and Military Ready Graduates: A Study of Efficiency in Texas Public School Districts

Public school districts in Texas and policymakers need studies of efficiency in the production of College, Career, and Military Ready graduates to maximize resources in the House Bill 3 funding formula and improve ratings in the Texas public school accountability system. A replication of efficiency studies by Carter (2012) and Thompson (2017), the purpose of this non-experimental quantitative study was to determine what discretionary and non-discretionary factors influence the efficiency of Texas public school districts’ production of College, Career, and Military Ready graduates. With financial and student performance data for 1054 school districts from the 2017-2018 school year, Data Envelopment Analysis (DEA) was used to measure the relative efficiency of each school district. A regression analysis found a significant positive influence on school district efficiency for total student enrollment. The percentage of non-white students and instructional expenditures per pupil did not have a significant influence on school district efficiency. This research study is useful to educators, legislators, and researchers for determining the allocation of resources for programs with the ability to produce College, Career, and Military Ready graduates

On Visible Homelessness and the Micro-Aesthetics of Public Space

In this article, we investigate the circumstances that have produced the current municipal regulatory approach to homelessness in the City of Melbourne, Victoria, and the ways in which visibly homeless people are policed through a micro-aesthetics of their presence in public space, which involves the monitoring of their bodily demeanour and their physical possessions. Our study contributes to and draws from a range of debates, including studies of the governmental conjunction of poverty and crime, analysis of the co-implication of law and spatiality, research on the criminalisation of homelessness and homeless people, and the burgeoning criminological interest in the significance of the visual field for our understandings of crime and criminality. This article recounts how homelessness, public space and questions of aesthetics have recently coalesced in debates about the regulation of homelessness in the public space of Melbourne’s city centre. It approaches the issues through comparative consideration of genres of municipal management frameworks in other jurisdictions, detailed textual consideration of the Protocol on Homelessness in the City of Melbourne and an empirical study of visible homelessness in the public places of central Melbourne

A Survey of Acidity in Drainage Waters and the Condition of Highway Drainage Installations

Every creek gulley and raw interrupted by roadway fills and embankments must be provided with an adequate drainage conduit under the pavement. If the natural drainage is impeded or the conduit is not functioning properly, impounded water over-runs the pavement, seeps through the fill, and eventually disintegrates the section or reduces its stability. The topography in Kentucky, through varied sectionally, requires on the average, one cross-drain for every thousand feet of roadway. Obviously, these drainage structures are of considerable economic importance in the highway program, not only from the standpoint of initial construction costs, but also from consideration of the service-efficiency or the permanence of the installation itself. Of these two factors, service-efficiency is undoubtedly the more important factor in determining an integrated service economy. Since permanence of a culvert or cross-drain depends largely on the specific properties of the material with which it is made, considerable advantage may be derived by selecting material for use in areas where their properties are compatible with the conditions of service, and excluding them where condition are known to be unfavorable