Gradients of galactic cosmic rays and anomalous components

Measurements of radial and latitudinal gradients of galactic cosmic rays and anomalous components now cover radii from 0.3 to 40 AU from the sun and latitudes up to 30 deg above the ecliptic plane for particle energies from approx. 10 MeV/n up to relativistic energies. The most accurate measurements cover the period 1972 through 1987, which includes more than one full 11 year cycle of solar activity. Radial gradients for glactic cosmic rays of all energies and species are small (similar to less than 10 percent AU), and variable in time, reaching a minimum of near 0 percent AU out to 30 AU for some species at solar maximum. Gradients for anomalous components are larger, of order 15 percent AU, may show similar time variability, and are relatively independent of particle species and energy. For the period 1985 through 1986 the intensity decreased away from the ecliptic for all species and energies. For galactic cosmic rays, the measured gradients are approx. 0.5 percent/degree near 20 AU, while for anomalous components the gradients are larger, ranging from 3 to 6 percent/degree. Comparison with a similar measurement for anomalous helium in 1975 through 1976 suggests that the latitude gradients for anomalous components have changed sign between 1975 and 1985. For galactic cosmic rays, the available evidence suggests no change in sign of the latitudinal gradient for relativistic particles

Galactic cosmic ray radial gradients and the anomalous He component near maximum solar modulation and to radii beyond 34 AU from the Sun

Radial gradients for relativistic galactic cosmic rays (E 70 MeV) remained nearly constant at approx. 2.5%/AU from 1978-84, which includes the period of maximum solar modulation in 1981-82. For energies 30-70 MeV/n, gradients decreased at solar maximum to values of 1%/AU (protons) and 4%/AU (helium), and appear to be increasing again in 1983-84 toward the values found for solar minimum. The anomalous helium component has not reappeared, either at 1 AU or at Pioneer 10 at R 34 AU

An LDEF 2 dust instrument for discrimination between orbital debris and natural particles in near-Earth space

The characteristics of a space dust instrument which would be ideally suited to carry out near-Earth dust measurements on a possible Long Duraction Exposure Facility reflight mission (LDEF 2) is discussed. As a model for the trajectory portion of the instrument proposed for LDEF 2, the characteristics of a SPAce DUSt instrument (SPADUS) currently under development for flight on the USA ARGOS mission to measure the flux, mass, velocity, and trajectory of near-Earth dust is summarized. Since natural (cosmic) dust and man-made dust particles (orbital debris) have different velocity and trajectory distributions, they are distinguished by means of the SPADUS velocity/trajectory information. The SPADUS measurements will cover the dust mass range approximately 5 x 10(exp -12) g (2 microns diameter) to approximately 1 x 10(exp -5) g (200 microns diameter), with an expected mean error in particle trajectory of approximately 7 deg (isotropic flux). Arrays of capture cell devices positioned behind the trajectory instrumentation would provide for Earth-based chemical and isotopic analysis of captured dust. The SPADUS measurement principles, characteristics, its role in the ARGOS mission, and its application to an LDEF 2 mission are summarized

Toward a descriptive model of galactic cosmic rays in the heliosphere

Researchers review the elements that enter into phenomenological models of the composition, energy spectra, and the spatial and temporal variations of galactic cosmic rays, including the so-called anomalous cosmic ray component. Starting from an existing model, designed to describe the behavior of cosmic rays in the near-Earth environment, researchers suggest possible updates and improvements to this model, and then propose a quantitative approach for extending such a model into other regions of the heliosphere

On the Spatial Distribution of Stellar Populations in the Large Magellanic Cloud

We measure the angular correlation function of stars in a region of the Large Magellanic Cloud (LMC) that spans 2 degrees by 1.5 degrees. We find that the correlation functions of stellar populations are represented well by exponential functions of the angular separation for separations between 2 and 40 arcmin (corresponding to ~ 30 pc and 550 pc for an LMC distance of 50 kpc). The inner boundary is set by the presence of distinct, highly correlated structures, which are the more familiar stellar clusters, and the outer boundary is set by the observed region's size and the presence of two principal centers of star formation within the region. We also find that the normalization and scale length of the correlation function changes systematically with the mean age of the stellar population. The existence of positive correlation at large separations (~300 pc), even in the youngest population, argues for large-scale hierarchical structure in current star formation. The evolution of the angular correlation toward lower normalizations and longer scale lengths with stellar age argues for the dispersion of stars with time. We show that a simple, stochastic, self-propagating star formation model is qualitatively consistent with this behavior of the correlation function.Comment: 30 pages, 13 Figures. Scheduled for publication in AJ in June 199

Utility FGD survey, January--December 1989. Volume 2, Design performance data for operating FGD systems: Part 3

Experimental data for 120 flue gas desulfurization systems of fossil-fuel power plants of US electrical utilities with information on the design and performance. No text--all data

Global Ethics and Nanotechnology: A Comparison of the Nanoethics Environments of the EU and China

The following article offers a brief overview of current nanotechnology policy, regulation and ethics in Europe and The People’s Republic of China with the intent of noting (dis)similarities in approach, before focusing on the involvement of the public in science and technology policy (i.e. participatory Technology Assessment). The conclusions of this article are, that (a) in terms of nanosafety as expressed through policy and regulation, China PR and the EU have similar approaches towards, and concerns about, nanotoxicity—the official debate on benefits and risks is not markedly different in the two regions; (b) that there is a similar economic drive behind both regions’ approach to nanodevelopment, the difference being the degree of public concern admitted; and (c) participation in decision-making is fundamentally different in the two regions. Thus in China PR, the focus is on the responsibility of the scientist; in the EU, it is about government accountability to the public. The formulation of a Code of Conduct for scientists in both regions (China PR’s predicted for 2012) reveals both similarity and difference in approach to nanotechnology development. This may change, since individual responsibility alone cannot guide S&T development, and as public participation is increasingly seen globally as integral to governmental decision-making

Effects of harvest season on carcass characteristics of lambs in the Intermountain West

Objective: The objectives of this study were to survey characteristics including hot carcass weight (HCW), 12th rib fat thickness (RFT), body-wall thickness (BWT), longissimus muscle area (LMA), USDA yield grade (USDA YG), percentage closely trimmed retail cuts (RC), and calculated yield grade (Calc YG) of lamb carcasses in the Intermountain West to determine the effects of season of slaughter and interrelationships among carcass characteristics. Materials and Methods: Lamb carcass characteristics were evaluated in 2 commercial Intermountain West processing plants over one year (n = 10,027). Carcasses were evaluated by season: spring (December–April, n = 2,322) and summer (May–August, n = 7,705). Results and Discussion: Carcasses of lambs slaughtered in the spring had 3.4 kg heavier HCW (P = 0.04) than those slaughtered in the summer. Subcutaneous fat (RFT; P = 0.06) and Calc YG (P = 0.09) tended to be greater in the spring than summer. Correlation coefficients and models of fit with a linear covariate of HCW indicated negative relationship between HCW and RC and positive relationship with all other carcass traits (P \u3c 0.001). Overall, graded lamb carcasses exceeded commercial processing plant preferred HCW (38.6 kg) by 5% (mean = 40.5 kg) and industry acceptable RFT (6 mm) by 25% (mean = 8.03 mm). Furthermore, 70% of lamb carcasses exceed 6 mm RFT. Implications and Applications: Season of slaughter contributed to differences in HCW and USDA YG but no other carcass characteristics. Still, carcass data surveyed from the largest lamb-producing region of the United States suggests that the degree of fatness exceeds industry preferences. Although abattoirs mitigate adverse effects of excessive fat through trimming and diverse market outlets, industry-wide efforts that agree on acceptable standards of trimness are needed. Transparent dialog across industry segments should be prioritized in addition to consistent integration of value-based pricing to reduce the proportion of excessively finished lambs

The large longitudinal spread of solar energetic particles during the January 17, 2010 solar event

We investigate multi-spacecraft observations of the January 17, 2010 solar energetic particle event. Energetic electrons and protons have been observed over a remarkable large longitudinal range at the two STEREO spacecraft and SOHO suggesting a longitudinal spread of nearly 360 degrees at 1AU. The flaring active region, which was on the backside of the Sun as seen from Earth, was separated by more than 100 degrees in longitude from the magnetic footpoints of each of the three spacecraft. The event is characterized by strongly delayed energetic particle onsets with respect to the flare and only small or no anisotropies in the intensity measurements at all three locations. The presence of a coronal shock is evidenced by the observation of a type II radio burst from the Earth and STEREO B. In order to describe the observations in terms of particle transport in the interplanetary medium, including perpendicular diffusion, a 1D model describing the propagation along a magnetic field line (model 1) (Dr\"oge, 2003) and the 3D propagation model (model 2) by (Dr\"oge et al., 2010) including perpendicular diffusion in the interplanetary medium have been applied, respectively. While both models are capable of reproducing the observations, model 1 requires injection functions at the Sun of several hours. Model 2, which includes lateral transport in the solar wind, reveals high values for the ratio of perpendicular to parallel diffusion. Because we do not find evidence for unusual long injection functions at the Sun we favor a scenario with strong perpendicular transport in the interplanetary medium as explanation for the observations.Comment: The final publication is available at http://www.springerlink.co