Garlic as an Alternative Anthelmintic in Sheep

An increase in the anthelmintic resistance of parasites in small ruminants and a push towards non-chemical farming has led researchers to search for alternative forms of anthelmintics. The efficacy of treating sheep by using natural garlic extract with respect to changes in weight, fecal egg counts (FEC), and packed cell volume (PCV) was investigated. Sheep were treated every 4 weeks for 8 weeks with saline (control) Ivermectin, or natural garlic extract and samples were collected weekly to determine FEC and PCV. Sheep were weighed at the time of sample collection to determine weight change. There were no significant differences between the Ivermectin and natural garlic extract treated sheep with respect to weight changes, FEC or PCV. The Ivermectin and natural garlic extract treated sheep had significantly greater (P \u3c 0.05) weight changes and PCV compared to the control. The control sheep had a significantly higher (P \u3c 0.05) FEC compared to the Ivermectin and natural garlic extract treated sheep. Administering natural garlic extract as anthelmintic is a variable alternative to Ivermectin

LDEF materials results for spacecraft applications: Executive summary

To address the challenges of space environmental effects, NASA designed the Long Duration Exposure Facility (LDEF) for an 18-month mission to expose thousands of samples of candidate materials that might be used on a space station or other orbital spacecraft. LDEF was launched in April 1984 and was to have been returned to Earth in 1985. Changes in mission schedules postponed retrieval until January 1990, after 69 months in orbit. Analyses of the samples recovered from LDEF have provided spacecraft designers and managers with the most extensive data base on space materials phenomena. Many LDEF samples were greatly changed by extended space exposure. Among even the most radially altered samples, NASA and its science teams are finding a wealth of surprising conclusions and tantalizing clues about the effects of space on materials. Many were discussed at the first two LDEF results conferences and subsequent professional papers. The LDEF Materials Results for Spacecraft Applications Conference was convened in Huntsville to discuss implications for spacecraft design. Already, paint and thermal blanket selections for space station and other spacecraft have been affected by LDEF data. This volume synopsizes those results

Characterization of three types of silicon solar cells for SEPS Deep Space Mission. Volume 3: Current-voltage characteristics of spectrolab sculptured BSR/P+ (K7), BSR/P+ (K6.5) and BSR (K4.5) cells as a function of temperature and intensity

Three types of high performance silicon solar cells, sculptured BSR/P+(K7), BSR/P+(K6.5) and BSR(K4.5) manufactured by Spectrolab were evaluated for their low temperature and low intensity performance. Sixteen cells of each type were subjected to 11 temperatures and 9 intensities. The sculptured BSR/P+(K7) cells provided the greatest maximum power output both at 1 AU and at LTLI conditions. The average efficiencies of this cell were 14.4 percent at 1 SC/+25 deg C and 18.5 percent at 0.086 SC/-100 deg C

Al0.2Ga0.8As 2 × 2 square pixel X-ray photodiode array

A monolithic 2 × 2 square pixel Al0.2Ga0.8As p+-i-n+ mesa X-ray photodiode array (each photodiode area 200 µm by 200 µm, 3 µm i layer) has been fabricated from material grown by MOVPE. The array was electrically characterised across the temperature range 100 °C to -20 °C. Each pixel’s response to illumination with soft X rays from an 55Fe radioisotope X-ray source (Mn Kα = 5.9 keV; Mn Kβ = 6.49 keV) was investigated across the temperature range 30 °C to -20 °C. The best energy resolution (FWHM at 5.9 keV) achieved at 20 °C was 0.76 keV ± 0.06 keV (with 30 V reverse bias applied to the detector). The measured energy resolution is the best so far reported for AlGaAs X-ray photodiodes at 20 °C. It is also the first time a small AlGaAs X-ray photodiode array has been demonstrated. Due to the temperature tolerance and the radiation hardness of AlGaAs, such detectors are expected to find utility in future space science missions exposed to intense radiation environments, for example missions to study the Jovian or Saturnian aurorae and high temperature planetary surfaces

Burning Surface Temperature Measurements of Propellants and Explosives using Phosphor Thermography

Temperature measurements of propellants and explosives are necessary to create accurate models which lead to better understanding of energetic characteristics such as burning rate. Previous attempts at measuring surface temperatures of burning propellants and explosives using thermocouples have suffered from large uncertainty. Thermographic phosphor thermography employs ceramic powders called phosphors whose spectroscopic properties can be used to remotely and nearly non-intrusively measure temperature. Improved methods were developed for application of this technique to energetic materials to yield more accurate, two-dimensional temperature measurements. In this study, zinc oxide doped with gallium, a thermographic phosphor, was mixed into HMX and RDX powder, two propellant ingredients. These were excited by a laser while burning, and the resulting luminescence was captured by a high-speed camera. The ratio of the intensity of the luminescence at two wavelength bands was measured, and the corresponding temperature dependence was used to determine the surface temperature of the burning materials based on prior calibrations. High precision has been achieved, although further experiments must be performed to validate the accuracy of the data. Methods have been developed to achieve high resolution and more optimal signal strength for this application of phosphor thermography. The experimental data may lead to more accurate accepted values for reacting surface temperatures and improved modeling of these energetic materials

Ultrashort pulses and short-pulse equations in (2+1)−(2+1)-dimensions

In this paper, we derive and study two versions of the short pulse equation (SPE) in $(2+1)-$dimensions. Using Maxwell's equations as a starting point, and suitable Kramers-Kronig formulas for the permittivity and permeability of the medium, which are relevant, e.g., to left-handed metamaterials and dielectric slab waveguides, we employ a multiple scales technique to obtain the relevant models. General properties of the resulting $(2+1)$-dimensional SPEs, including fundamental conservation laws, as well as the Lagrangian and Hamiltonian structure and numerical simulations for one- and two-dimensional initial data, are presented. Ultrashort 1D breathers appear to be fairly robust, while rather general two-dimensional localized initial conditions are transformed into quasi-one-dimensional dispersing waveforms

Characterization of a 5-eV neutral atomic oxygen beam facility

An experimental effort to characterize an existing 5-eV neutral atomic oxygen beam facility being developed at Princeton Plasma Physics Laboratory is described. This characterization effort includes atomic oxygen flux and flux distribution measurements using a catalytic probe, energy determination using a commercially designed quadrupole mass spectrometer (QMS), and the exposure of oxygen-sensitive materials in this beam facility. Also, comparisons were drawn between the reaction efficiencies of materials exposed in plasma ashers, and the reaction efficiencies previously estimated from space flight experiments. The results of this study show that the beam facility is capable of producing a directional beam of neutral atomic oxygen atoms with the needed flux and energy to simulate low Earth orbit (LEO) conditions for real time accelerated testing. The flux distribution in this facility is uniform to +/- 6 percent of the peak flux over a beam diameter of 6 cm

AlGaAs 55Fe X-ray radioisotope microbattery

This paper describes the performance of a fabricated prototype Al0.2Ga0.8As 55Fe radioisotope microbattery photovoltaic cells over the temperature range −20 °C to 50 °C. Two 400 μm diameter p+-i-n+ (3 μm i-layer) Al0.2Ga0.8As mesa photodiodes were used as conversion devices in a novel X-ray microbattery prototype. The changes of the key microbattery parameters were analysed in response to temperature: the open circuit voltage, the maximum output power and the internal conversion efficiency decreased when the temperature was increased. At −20 °C, an open circuit voltage and a maximum output power of 0.2 V and 0.04 pW, respectively, were measured per photodiode. The best internal conversion efficiency achieved for the fabricated prototype was only 0.95% at −20 °C