CC204 Revised 1969 Weed Control in Sugar Beets

Campaign Circular 204 Revised 1969 discusses weed control in sugar beets

WIPP/SRL in-situ tests: MIIT program--The effects of metal package components

The Materials Interface Interactions Tests or MIIT is the largest in-situ testing program in progress, involving burial of many simulated nuclear waste systems and accompanying package components. In MIIT, waste glass samples were fabricated into the shape of `pineapple slices`, polished on one side. Proposed package components were also made into a similar configuration and the various glasses, metals, and geologic samples were than stacked onto heater elements within Teflon assemblies. This produced interactions of interest by creating glass/glass, glass/salt, and glass/metal interfaces. Since the outer diameter of the metal was smaller than the outer diameter of the glass, a lip was created which was also produced a glass/liquid interface, which was also studied. Overall, a total of 50 stacks or assemblies of pineapple slices were created in seven different stacking arrangements. Each individual assembly was then installed in an instrumented borehole at WIPP. Brine was then added to most of boreholes and the assemblies heated and maintained at 90{degrees}C. This was achieved by energizing the central heating and rod that traversed through the middle opening of each of the pineapple slices in each assembly. Due to the design of these units, glass, metal and geologic samples could be removed at time intervals of 6 mos., 1 year, 2 years, and 5 years. Currently, all but the 5 year samples have been removed from test and are being evaluated in laboratories of MIIT participants

Measurement of a surface heat flux and temperature

The Heat Flux Microsensor is a new sensor which was recently patented by Virginia Tech and is just starting to be marketed by Vatell Corp. The sensor is made using the thin-film microfabrication techniques directly on the material that is to be measured. It consists of several thin-film layers forming a differential thermopile across a thermal resistance layer. The measured heat flux q is proportional to the temperature difference across the resistance layer q= k(sub g)/delta(sub g) x (t(sub 1) - T(sub 2)), where k(sub g) is the thermal conductivity and delta (sub g) is the thickness of the thermal resistance layer. Because the gages are sputter coated directly onto the surface, their total thickness is less than 2 micrometers, which is two orders of magnitude thinner than previous gages. The resulting temperature difference across the thermal resistance layer (delta is less than 1 micrometer) is very small even at high heat fluxes. To generate a measurable signal many thermocouple pairs are put in series to form a differential thermopile. The combination of series thermocouple junctions and thin-film design creates a gage with very attractive characteristics. It is not only physically non-intrusive to the flow, but also causes minimal disruption of the surface temperature. Because it is so thin, the response time is less than 20 microsec. Consequently, the frequency response is flat from 0 to over 50 kHz. Moreover, the signal of the Heat Flux Microsensor is directly proportional to the heat flux. Therefore, it can easily be used in both steady and transient flows, and it measures both the steady and unsteady components of the surface heat flux. A version of the Heat Flux Microsensor has been developed to meet the harsh demands of combustion environments. These gages use platinum and platinum-10 percent rhodium as the thermoelectric materials. The thermal resistance layer is silicon monoxide and a protective coating of Al2O3 is deposited on top of the sensor. The superimposed thin-film pattern of all six layers is presented. The large pads are for connection with pins used to bring the signal out the back of the ceramic. In addition to the heat flux measurement, the surface temperature is measured with a platinum resistance layer (RTS). The resistance of this layer increases with increasing temperature. Therefore, these gages simultaneously measure the surface temperature and heat flux. The demonstrated applications include rocket nozzles, SCRAM jet engines, gas turbine engines, boiling heat transfer, flame experiments, basic fluid heat transfer, hypersonic flight, and shock tube testing. The laboratory involves using one of these sensors in a small combustion flame. The sensor is made on a 2.5 cm diameter piece of aluminum nitride ceramic

G92-1071 Ridge Plant Systems: Weed Control

Advantages and disadvantages of the ridge plant system, weed control before and at planting and economics of the system are discussed. Ridge planting combines tillage and herbicides to achieve improved weed control in row crops. Crop seed is planted into ridges formed during cultivation and/or ditching of the previous crop. In ridge planting, the planter follows the old row and ridge clearing sweeps or disks move the surface soil, residue and much of the weed seed out of the row. Weed seeds are deposited between the rows where, upon germination, they can be controlled with cultivation. Two cultivations are generally used for weed control. The first cultivation loosens the soil and the second rebuilds the ridge. The ridge plant system is well suited to furrow-irrigationd crops. It also works well with dryland crops or those under center pivot irrigation. On furrow irrigationd land, corn or sorghum stalks may need to be shredded to assist in decomposition and hence irrigation because crop residue slows water advance in the furrow. Slowing the water may be a benefit, however, on soils which have a low water intake rate. With center pivot and dryland acres the need for shredding depends on how much residue the cultivator can handle

Deriving the bulk properties of solar wind electrons observed by Solar Orbiter: A preliminary study of electron plasma thermodynamics

We demonstrate the calculation of solar wind electron bulk parameters from recent observations by Solar Wind Analyser Electron Analyser System on board Solar Orbiter. We use our methods to derive the electron bulk parameters in a time interval of a few hours. We attempt a preliminary examination of the polytropic behavior of the electrons by analyzing the derived electron density and temperature. Moreover, we discuss the challenges in analyzing the observations due to the spacecraft charging and photo-electron contamination in the energy range < 10 eV. Aims: We derive bulk parameters of thermal solar wind electrons by analyzing Solar Orbiter observations and we investigate if there is any typical polytropic model that applies to the electron density and temperature fluctuations. Methods: We use the appropriate transformations to convert the observations to velocity distribution functions in the instrument frame. We then derive the electron bulk parameters by a) calculating the statistical moments of the constructed velocity distribution functions and b) by fitting the constructed distributions with analytical expressions. We firstly test our methods by applying them to an artificial data-set, which we produce by using the forward modeling technique. Results: The forward model validates the analysis techniques which we use to derive the electron bulk parameters. The calculation of the statistical moments and the fitting method determines bulk parameters that are identical within uncertainty to the input parameters we use to simulate the plasma electrons in the first place. An application of our analysis technique to the data reveals a nearly isothermal electron "core". The results are affected by the spacecraft potential and the photo-electron contamination, which we need to characterize in detail in future analyses

G92-1071 Ridge Plant Systems: Weed Control

Advantages and disadvantages of the ridge plant system, weed control before and at planting and economics of the system are discussed. Ridge planting combines tillage and herbicides to achieve improved weed control in row crops. Crop seed is planted into ridges formed during cultivation and/or ditching of the previous crop. In ridge planting, the planter follows the old row and ridge clearing sweeps or disks move the surface soil, residue and much of the weed seed out of the row. Weed seeds are deposited between the rows where, upon germination, they can be controlled with cultivation. Two cultivations are generally used for weed control. The first cultivation loosens the soil and the second rebuilds the ridge. The ridge plant system is well suited to furrow-irrigationd crops. It also works well with dryland crops or those under center pivot irrigation. On furrow irrigationd land, corn or sorghum stalks may need to be shredded to assist in decomposition and hence irrigation because crop residue slows water advance in the furrow. Slowing the water may be a benefit, however, on soils which have a low water intake rate. With center pivot and dryland acres the need for shredding depends on how much residue the cultivator can handle

MIIT: International in-situ testing of nuclear-waste glasses: Performance of SRS simulated waste glass after five years of burial at the Waste Isolation Pilot Plant (WIPP)

In July of 1986, the first in-situ test involving burial of simulated high-level waste (HLW) forms conducted in the United States was started. This program, called the Materials Interface Interactions Test or MIIT, comprises the largest, most cooperative field-testing venture in the international waste management community. In July of 1991, the experimental portion of the 5-year MIIT study was completed on schedule. During this time interval, many in-situ measurements were performed, thousands of brine analyses conducted, and hundreds of waste glass and package components exhumed and evaluated after 6 mo., 1 yr., 2 yr. and 5 yr. burial periods. Although analyses are still in progress, the performance of SRS waste glass based on all data currently available has been seen to be excellent thus far. Initial analyses and assessment of Savannah River (SR) waste glass after burial in WIPP at 90{degrees}C for 5 years are presented in this document