Local effects of partly cloudy skies on solar and emitted radiations

Solar radiation measurements are made on a routine basis. Global solar, atmospheric emitted, downwelled diffuse solar, and direct solar radiation measurement systems are fully operational with the first two in continuous operation. Fractional cloud cover measurements are made from GOES imagery or from ground based whole sky photographs. Normalized global solar irradiance values for partly cloudy skies were correlated to fractional cloud cover

Local effects of partly-cloudy skies on solar and emitted radiation

A computer automated data acquisition system for atmospheric emittance, and global solar, downwelled diffuse solar, and direct solar irradiances is discussed. Hourly-integrated global solar and atmospheric emitted radiances were measured continuously from February 1981 and hourly-integrated diffuse solar and direct solar irradiances were measured continuously from October 1981. One-minute integrated data are available for each of these components from February 1982. The results of the correlation of global insolation with fractional cloud cover for the first year's data set. A February data set, composed of one-minute integrated global insolation and direct solar irradiance, cloud cover fractions, meteorological data from nearby weather stations, and GOES East satellite radiometric data, was collected to test the theoretical model of satellite radiometric data correlation and develop the cloud dependence for the local measurement site

Effects of cosmic rays on single event upsets

Assistance was provided to the Brookhaven Single Event Upset (SEU) Test Facility. Computer codes were developed for fragmentation and secondary radiation affecting Very Large Scale Integration (VLSI) in space. A computer controlled CV (HP4192) test was developed for Terman analysis. Also developed were high speed parametric tests which are independent of operator judgment and a charge pumping technique for measurement of D(sub it) (E). The X-ray secondary effects, and parametric degradation as a function of dose rate were simulated. The SPICE simulation of static RAMs with various resistor filters was tested

Kinetic theory of cluster impingement in the framework of statistical mechanics of rigid disks

The paper centres on the evaluation of the function n(theta)=N(theta)/N0, that is the normalized number of islands as a function of coverage 0<theta<1, given N0 initial nucleation centres (dots) having any degree of spatial correlation. A mean field approach has been employed: the islands have the same size at any coverage. In particular, as far as the random distribution of dots is concerned, the problem has been solved by considering the contribution of binary collisions between islands only. With regard to correlated dots, we generalize a method previously applied to the random case only. In passing, we have made use of the exclusion probability reported in [S. Torquato, B. Lu, J. Rubinstein, Phys.Rev.A 41, 2059 (1990)], for determining the kinetics of surface coverage in the case of correlated dots, improving our previous calculation [M. Tomellini, M. Fanfoni, M. Volpe Phys. Rev.B 62, 11300, (2000)].Comment: 10 pages, 3 figure

Coupling ammonia-N production with ammonia-N uptake in the rumen

Abstract only availableMicrobial efficiency is defined as a measure of microbial yield in the rumen per unit of organic matter fermented. Because the ruminant is dependant on microbial mass for its supply of amino acids, the nutritional goal is to maximize microbial efficiency. However, an excessive supply of nutrients to rumen microbes can result in waste. Excessive waste can have negative economic and environmental consequences. A study was conducted to determine if prediction of ammonia-N release could be optimized with bacterial ammonia uptake in the rumen. The hypothesis of this research was that a diet could be formulated such that ammonia-N release would match the ammonia uptake by rumen microflora. To test this hypothesis, a continuous culture system of twenty fermentors placed in a 39ºC water bath was used. Dietary treatments were basal, 0.33X, 0.66X, X, and 1.33X. The optimal diet (diet X) was formulated using substrates with complementary degradation rates in order to maintain an optimal ammonia level of 2 mM (Satter & Slyter, 1973). Following an acclimation period of 4 days, samples were collected for 3 days. Collected samples were analyzed for organic matter digestibility (OMD), concentration of volatile fatty acids (VFA), pH, and microbial efficiency. Microbial efficiency was maximized for diet X. As the degradable protein level increased in the diet, VFA increased and pH decreased. The degradable protein level did not influence OMD. Conclusions from this data were that increasing degradable protein increased fermentative activity but not microbial yield. We further deduced that previous research conducted in our laboratory was valid in concluding that ammonia-N requirements could be modeled. This will enhance diet formulation for ruminants.F.B. Miller Animal Sciences Summer Undergraduate Research Progra

Determination of biomembrane bending moduli in fully atomistic simulations.

The bilayer bending modulus (Kc) is one of the most important physical constants characterizing lipid membranes, but precisely measuring it is a challenge, both experimentally and computationally. Experimental measurements on chemically identical bilayers often differ depending upon the techniques employed, and robust simulation results have previously been limited to coarse-grained models (at varying levels of resolution). This Communication demonstrates the extraction of Kc from fully atomistic molecular dynamics simulations for three different single-component lipid bilayers (DPPC, DOPC, and DOPE). The results agree quantitatively with experiments that measure thermal shape fluctuations in giant unilamellar vesicles. Lipid tilt, twist, and compression moduli are also reported

Simulation to Support Local Search in Trajectory Optimization Planning

NASA and the international community are investing in the development of a commercial transportation infrastructure that includes the increased use of rotorcraft, specifically helicopters and civil tilt rotors. However, there is significant concern over the impact of noise on the communities surrounding the transportation facilities. One way to address the rotorcraft noise problem is by exploiting powerful search techniques coming from artificial intelligence coupled with simulation and field tests to design low-noise flight profiles which can be tested in simulation or through field tests. This paper investigates the use of simulation based on predictive physical models to facilitate the search for low-noise trajectories using a class of automated search algorithms called local search. A novel feature of this approach is the ability to incorporate constraints directly into the problem formulation that addresses passenger safety and comfort