Analysis and methodology for aeronautical systems technology program planning

A structured methodology was developed that allows the generation, analysis, and rank-ordering of system concepts by their benefits and costs, indicating the preferred order of implementation. The methodology is supported by a base of data on civil transport aircraft fleet growth projections and data on aircraft performance relating the contribution of each element of the aircraft to overall performance. The performance data are used to assess the benefits of proposed concepts. The methodology includes a computer program for performing the calculations needed to rank-order the concepts and compute their cumulative benefit-to-cost ratio. The use of the methodology and supporting data is illustrated through the analysis of actual system concepts from various sources

A closed form solution to HZE propagation

An analytic solution for high energy heavy ion transport assuming straightahead and velocity conserving interactions with constant nuclear cross reactions is given in terms of a Green's function. The series solution for the Green's function is rapidly convergent for most practical applications. The Green's function technique can be applied with equal success to laboratory beams as well as to galactic cosmic rays allowing laboratory validation of the resultant space shielding code

BRYNTRN: A baryon transport model

The development of an interaction data base and a numerical solution to the transport of baryons through an arbitrary shield material based on a straight ahead approximation of the Boltzmann equation are described. The code is most accurate for continuous energy boundary values, but gives reasonable results for discrete spectra at the boundary using even a relatively coarse energy grid (30 points) and large spatial increments (1 cm in H2O). The resulting computer code is self-contained, efficient and ready to use. The code requires only a very small fraction of the computer resources required for Monte Carlo codes

Nucleon-nucleus interaction data base: Total nuclear and absorption cross sections

Neutron total cross sections are represented for Li to Pu targets at energies above 0.1 MeV and less than 100 MeV using a modified nuclear Ramsauer formalism. The formalism is derived for energies above 100 MeV by fitting theoretical cross sections. Neutron absorption cross sections are represented by analytic expressions of similar form, but shape resonance phenomena of the Ramsauer effect is not present. Elastic differential cross sections are given as a renormalized impulse approximation. These cross section data bases are useful for nucleon transport applications

Stable isotope analysis indicates resource partitioning and trophic niche overlap in larvae of four tuna species in the Gulf of Mexico

In this study we assessed the trophic ecology of bluefin tuna Thunnus thynnus larvae from the Gulf of Mexico, together with the co-occurring larvae of blackfin tuna T. atlanticus, bullet tuna Auxis rochei, and skipjack Katsuwonus pelamis, using both bulk-tissue stable isotope analysis (SIAbulk) and compound-specific analysis of amino acids (CSIAAA). Bulk nitrogen (δ15Nbulk) and carbon (δ13Cbulk) values differed significantly among species, suggesting partitioning of resources due to an adaptive process allowing these tunas to share the ecosystem’s trophic resources during this early life period. K. pelamis had the largest isotopic niche width, likely due to piscivorous feeding at an earlier age compared to the other species, with an isotopic niche overlap of 17.5% with T. thynnus, 15.8% with T. atlanticus, and 31.2% with A. rochei. This trophic overlap suggests a mix of competition and trophic differentiation among these 4 species of tuna larvae. Higher nitrogen isotopic signatures in preflexion versus postflexion larvae of T. thynnus measured using both SIAbulk and CSIAAA indicate maternal isotopic transmission, as well as ‘capital breeder’-like characteristics. In contrast, the nitrogen isotopic ratios of the other 3 species were similar between ontogenetic stages. These observations suggest different breeding strategies within the study area for T. atlanticus, K. pelamis, and A. rochei compared to T. thynnus. No significant differences were observed among the 4 species’ trophic positions (TPs) estimated by CSIAAA, whereas a higher TP was observed for T. thynnus by SIAbulk. These differences in TP estimation may be attributed to discrepancies in baseline estimates.Postprint2,48

Magnetic and intruder rotational bands in (113)In

©2005 American Physical SocietyExcited states in ¹¹³In were populated via the reactions ¹⁰⁰Mo(¹⁸O,p4n)¹¹³In and ¹¹⁰Pd(7Li,4n)¹¹³In. The two known ΔJ = 2 intruder bands, based on the πg7/2 ⊗ d5/2 and πh11/2 orbitals, have been extended by 8¯h to spins (49/2+)¯h and (55/2−)¯h, respectively. The previous finding of three sequences of ΔJ = 1 γ -ray transitions has been confirmed. A self-consistent cranked shell-model calculation gives a good description of the contrasting alignment patterns of the two ΔJ = 2 intruder bands. The intruder bands, the known sequences ofM1 transitions, and spherical levels together represent a coexistence of three different excitation modes in this nucleus.S. Naguleswaran, R. S. Chakrawarthy, U. Garg, K. L. Lamkin, G. Smith, J. C. Walpe, A. Galindo-Uribarri, V. P. Janzen, D. C. Radford, R. Kaczarowski, D. B. Fossan, D. R. Lafosse, P. Vaska, Ch. Droste, T. Morek, S. Pilotte, J. DeGraaf, T. Drake, and R. Wys

LARVAL BLUEFIN TUNA (THUNNUS THYNNUS) TROPHODYNAMICS FROM BALEARIC SEA (WM) AND GULF OF MEXICO SPAWNING ECOSYSTEMS BY STABLE ISOTOPE

The present study uses stable isotopes of nitrogen and carbon (δ15N and δ13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6-10 mm SL) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). The study analyzes ontogenetic changes in the food sources and trophic levels (TL) of BFT larvae from each spawning habitat. The results discuss differences in the ontogenic dietary shifts observed in the BFT larvae from the GOM and MED as well as trophodynamic differences in relation to the microzooplanktonic baselines used for estimating trophic enrichment. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their early life growth strategy.Versión de edito

Do western Atlantic bluefin tuna spawn outside of the Gulf of Mexico? Results from a larval survey in the Atlantic Ocean in 2013

In 2013, a larval survey was conducted north and east of the Bahamas aboard the NOAA Ship NANCY FOSTER. Sampling areas were selected based on larval habitat model predictions, and daily satellite analysis of surface temperature and ocean color. Samples were collected at 97 stations, and 18 larval BFT (Thunnus thynnus) were found at 9 stations. Six of these stations came from oceanographically complex regions characterized by cyclonic and anticyclonic gyres. Larvae ranged in size from 3.22mm to 7.58 mm, corresponding to approximately 5-12 days in age. Analysis of satellite derived surface currents and CTD data suggest that these larvae were spawned and retained in this area. Larval habitat models show areas of high predicted abundance extending east to 650 W, but the actual extent of spawning in this area remains unknown.En prens

Smoking trends among adolescents from 1990 to 2002 in ten European countries and Canada

BACKGROUND: Daily smoking adolescents are a public health problem as they are more likely to become adult smokers and to develop smoking-related health problems later on in their lives. METHODS: The study is part of the four-yearly, cross-national Health Behaviour in School-aged Children study, a school-based survey on a nationally representative sample using a standardised methodology. Data of 4 survey periods are available (1990–2002). Gender-specific daily smoking trends among 14–15 year olds are examined using logistic regressions. Sex ratios are calculated for each survey period and country. Interaction effects between period and gender are examined. RESULTS: Daily smoking prevalence in boys in 2002 ranges from 5.5% in Sweden to 20.0% in Latvia. Among girls, the daily smoking prevalence in 2002 ranges from 8.9% in Poland to 24.7% in Austria. Three daily smoking trend groups are identified: countries with a declining or stagnating trend, countries with an increasing trend followed by a decreasing trend, and countries with an increasing trend. These trend groups show a geographical pattern, but are not linked to smoking prevalence. Over the 4 surveys, the sex ratio has changed in Belgium, Switzerland, and Latvia. CONCLUSION: Among adolescents in Europe, three groups of countries in a different stage of the smoking epidemic curve can be identified, with girls being in an earlier stage than boys. In 2002, large differences in smoking prevalence between the countries have been observed. This predicts a high mortality due to smoking over 20–30 years for some countries, if no policy interventions are taken