Random pulse generator

An exemplary embodiment of the present invention provides a source of random width and random spaced rectangular voltage pulses whose mean or average frequency of operation is controllable within prescribed limits of about 10 hertz to 1 megahertz. A pair of thin-film metal resistors are used to provide a differential white noise voltage pulse source. Pulse shaping and amplification circuitry provide relatively short duration pulses of constant amplitude which are applied to anti-bounce logic circuitry to prevent ringing effects. The pulse outputs from the anti-bounce circuits are then used to control two one-shot multivibrators whose output comprises the random length and random spaced rectangular pulses. Means are provided for monitoring, calibrating and evaluating the relative randomness of the generator

Pulse stretcher for narrow pulses

Pulse stretching circuit can linearly stretch pulses as narrow as 50 nanoseconds and block incoming pulses following accepted input pulse until processing has been completed. It also removes baseline distortion by being completely direct coupled and provides monitor output which measures true number of input events that exceed predetermined threshold

Development, Survival and Phenology of the Sweetclover Weevil Parasitoid, \u3ci\u3ePygostolus Falcatus\u3c/i\u3e (Hymenoptera: Braconidae)

Biennial sweetclovers were widely used for soil improvement and as for- ages in the first half of the 1900s. The introduction of the sweetclover weevil, Sitona cylindricollis, caused a drastic decline in sweetclover acreage. In North Dakota, yellow sweetclover, Melilotus officinalis, is still the legume of choice on organic farms. In an effort to control the weevil, the thelyotokous parasitoid Pygostolus falcatus was imported. Parasitoids were studied for temperature-dependent development, and adult longevity as influenced by temperature and availability of provisions. Development from egg to adult at 15, 20, 25 and 30°C was 58, 28, 22 and 21 d, respectively. No parasitoids were reared out at 10°C, although diapausing first instars were present. Longevity of adult parasitoids provided honey, water, sweetclover and sweet- clover weevils at 15, 20, 25 and 30°C was 29, 22, 12 and 6 d, respectively. Adults provided the following combinations of provisions at 25°C survived for: nothing-2 d; water-2 d; honey-4 d; honey and water - 6 d; honey, water and sweetclover - 11 d; honey, water, sweetclover and hosts - 12 d. Field cage releases and a degree-day model developed for the parasitoid demonstrated that poor synchrony between P. falcatus and the sweetclover weevil hinders its usefulness as a biological control agent

Comparative Study of Photosynthesis Rates between Native Red Maple and Invasive Norway Maple in the Eastern Deciduous Forest

Invasive species, such as the Norway Maple, are often able to outcompete native species, such as the Red Maple by performing more efficiently in the environment compared to the native species. In this study, we examined if the Norway maple was able to outcompete the Red Maple in the Eastern Deciduous Forest because the Norway Maple had a higher rate of photosynthesis. The study found that the Norway Maple leaves had a slightly higher rate of carbon dioxide consumption than Red Maple leaves and that the Red Maple leaves had a higher rate of oxygen production compared to the Norway Maples. Since these differences were not statistically significant, the data suggested that the differences in the rate of photosynthesis between the two tree species is most likely very small. This suggests that the rate of photosynthesis is most likely not the advantage Norway Maples have over Red Maples that allows this invader to better compete for space in a forest

A Long-Term Analysis of Changes in Farm Size and Financial Performance

This paper examined the changing structure of farms in Kansas. Specifically, changes in farm size, farm type, financial performance, and economies of size were examined using five-year moving averages from 1973 to 2007. Convergence analysis was used to determine whether small farms are catching up to larger farms or whether the difference in performance between these two groups of farms was widening. Results suggested that the gaps between the small farms and large farms have widened.Economies of Size, Financial Performance, Farm Management, Production Economics, D21,

Marginal Propensity to Consume for a Sample of Kansas Farms

This paper examined the marginal propensity to consume (MPC) for a sample of Kansas farms. Sensitivity of estimated MPCs to the use of accrual net farm income, net cash farm income, and the inclusion of off-farm income was also examined. Results yielded a range of short-run MPCs from 0.011 to 0.015. Statistical tests suggested that the income coefficients used to compute short-run MPCs were not statistically different.Farm Consumption, Habit Persistence, Agricultural Finance, Farm Management, E21,

Hardware simulation of Ku-band spacecraft receiver and bit synchronizer, volume 1

A hardware simulation which emulates an automatically acquiring transmit receive spread spectrum communication and tracking system and developed for use in future NASA programs involving digital communications is considered. The system architecture and tradeoff analysis that led to the selection of the system to be simulated is presented

Hazards to golden-mantled ground squirrels and associated secondary hazard potential from strychnine baiting for forest pocket gophers

Radio telemetry and capture-recapture techniques were used to evaluate the hazards to golden-mantled ground squirrels (Spermophilus lateralis) from hand baiting with 0.5% strychnine-treated oats for western pocket gophers (Thomomys mazama) on conifer plantations in eastern Oregon. Toxicology data were collected on field-killed and caged ground squirrels and on caged mink (Mustela vison), great horned owls (Bubo virginianus), and red-tailed hawks (Buteo jamaicensis). Ground squirrel populations were reduced 50 to 75% following underground baiting for pocket gophers. Maximum amount of strychnine alkaloid found in cheek pouches and carcass of a field-killed golden-mantled ground squirrel was 2.88 mg. Mean amount of strychnine in carcasses was 0.35 mg; almost all occurred in the gut. The estimated LD50 for mink was 0.6 mg/kg. The lowest lethal dose for great horned owls and red-tailed hawks was 7.7 mg/kg and 10.2 mg/kg, respectively. The LD50 for owls and hawks was not determined. Long-term effects on golden-mantled ground squirrel populations and secondary hazard potential to owls and hawks were judged to be minimal. Wild mustelids as large as mink could be adversely affected by consuming the gut content of strychnine-killed golden-mantled ground squirrels

Hardware simulation of KU-band spacecraft receiver and bit synchronizer, phase 2, volume 1

The acquisition behavior of the PN subsystem of an automatically acquiring spacecraft receiver was studied. A symbol synchronizer subsystem was constructed and integrated into the composite simulation of the receiver. The overall performance of the receiver when subjected to anomalies such as signal fades was evaluated. Potential problems associated with PN/carrier sweep interactions were investigated