Land use in the northern Coachella Valley

Satellite imagery has proved to have great utility for monitoring land use change and as a data source for regional planning. In California, open space desert resources are under severe pressure to serve as a source for recreational gratification to individuals living in the heavily populated southern coastal plain. Concern for these sensitive arid environments has been expressed by both federal and state agencies. The northern half of the Coachella Valley has historically served as a focal point for weekend recreational activity and second homes. Since demand in this area has remained high, land use change from rural to urban residential has been occurring continuously since 1968. This area of rapid change is an ideal site to illustrate the utility of satellite imagery as a data source for planning information, and has served as the areal focus of this investigation

Exploration of the Public School Education: Still Perpetuating Indoctrination in our Modern World

Senior Project submitted to The Division of Social Studies of Bard College

Experimental Wear Modelling of Lifeboat Slipway Launches

It is necessary to use an inclined slipway to launch lifeboats in locations where there is no natural harbour. Slipway stations consist of an initial roller section followed by an inclined keelway, the lifeboat is released from the top of the slipway and proceeds under its own weight into the water. Contact is between the lifeboat keel and a lined, greased keelway and this that determines the friction along the slipway. This paper describes a bench test methodology to investigate this contact. The selection of a modified TE57 reciprocating tribometer and design of a modified pin on plate arrangement is discussed. A test schedule for both the original nickel/chromium coated steel lining and the new low-friction jute fibre/phenolic resin composite lining is developed to accurately reflect real world conditions including environmental contamination such as seawater or wind-blown sand. Environmentally conscious lubricants including water and bio-greases are investigated and compared for their effects in reducing slipway panel friction and wear. Experimental data is collected to establish wear mechanisms, wear volumes and friction characteristics for a range of lubricants and environmental contaminants for the two most common lifeboat keelway lining materials. Implications of this research for future lifeboat slipway design are discussed

Longer thaw seasons increase nitrogen availability for leaching during fall in tundra soils

Climate change has resulted in warmer soil temperatures, earlier spring thaw and later fall freeze-up, resulting in warmer soil temperatures and thawing of permafrost in tundra regions. While these changes in temperature metrics tend to lengthen the growing season for plants, light levels, especially in the fall, will continue to limit plant growth and nutrient uptake. We conducted a laboratory experiment using intact soil cores with and without vegetation from a tundra peatland to measure the effects of late freeze and early spring thaw on carbon dioxide (CO2) exchange, methane (CH4) emissions, dissolved organic carbon (DOC) and nitrogen (N) leaching from soils. We compared soil C exchange and N production with a 30 day longer seasonal thaw during a simulated annual cycle from spring thaw through freeze-up and thaw. Across all cores, fall N leaching accounted for ~33% of total annual N loss despite significant increases in microbial biomass during this period. Nitrate $({{{\rm{NO}}}_{3}}^{-})$ leaching was highest during the fall (5.33 ± 1.45 mg N m−2 d−1) following plant senescence and lowest during the summer (0.43 ± 0.22 mg N m−2 d−1). In the late freeze and early thaw treatment, we found 25% higher total annual ecosystem respiration but no significant change in CH4 emissions or DOC loss due to high variability among samples. The late freeze period magnified N leaching and likely was derived from root turnover and microbial mineralization of soil organic matter coupled with little demand from plants or microbes. Large N leaching during the fall will affect N cycling in low-lying areas and streams and may alter terrestrial and aquatic ecosystem nitrogen budgets in the arctic

Kojonup maintenance Phosphorus and Sulphur Trial 68BR7EX

68BR7 Maintenance superphosphate and sulphur trial To determine the level of superphosphate to maintain near maximum plant and animal production with and without additional elemental sulphur. Experimental: There are 41 plots with 29 treatments. 12 treatments have 2 replications. Site: Very old land, whitegum and sheoak vegetation with greybrown sandy loam and some quartz grit. History: Superphosphate - 1/2bag for 40 years - 3,600 lbs (1633 kg). 600 lb (272 kg) in the last 4 years to 1967

Theory of adhesion: role of surface roughness

We discuss how surface roughness influence the adhesion between elastic solids. We introduce a Tabor number which depends on the length scale or magnification, and which gives information about the nature of the adhesion at different length scales. We consider two limiting cases relevant for (a) elastically hard solids with weak adhesive interaction (DMT-limit) and (b) elastically soft solids or strong adhesive interaction (JKR-limit). For the former cases we study the nature of the adhesion using different adhesive force laws ($F\sim u^{-n}$, $n=1.5-4$, where $u$ is the wall-wall separation). In general, adhesion may switch from DMT-like at short length scales to JKR-like at large (macroscopic) length scale. We compare the theory predictions to the results of exact numerical simulations and find good agreement between theory and the simulation results