Study to minimize hydrogen embrittlement of ultrahigh-strength steels

Hydrogen-stress cracking in high-strength steels is influenced by hydrogen content of the material and its hydrogen absorption tendency. Non-embrittling cleaning, pickling, and electroplating processes are being studied. Protection from this hydrogen embrittlement is important to the aerospace and aircraft industries

The radio-infrared correlation in galaxies

The radio-infrared correlation was explained as a direct and linear relationship between star formation and IR emission. However, one fact making the IR-star formation linkage less obvious is that the IR emission consists of at least two emission components, cold dust and warm dust. The cold dust emission may not be directly linked to the young stellar population. Furthermore, understanding the origin of the radio-IR correlation requires to discriminate between the two main components of the radio continuum emission, free-free and synchrotron emission. Here, we present a multi-scale study of the correlation of IR with both the thermal and non-thermal (synchrotron) components of the radio continuum emission from the nearby galaxies M33 and M31.Comment: To appear in Highlights of Astronomy, Volume 15, XXVIIth IAU General Assembly, August 200

Destruction of chain-superconductivity in YBa_2Cu_4O_8 in a weak magnetic field

We report measurements of the temperature dependent components of the magnetic penetration depth {\lambda}(T) in single crystal samples of YBa_2Cu_4O_8 using a radio frequency tunnel diode oscillator technique. We observe a downturn in {\lambda}(T) at low temperatures for currents flowing along the b and c axes but not along the a axis. The downturn in {\lambda}_b is suppressed by a small dc field of ~0.25 T. This and the zero field anisotropy of {\lambda}(T) likely result from proximity induced superconducting on the CuO chains, however we also discuss the possibility that a significant part of the anisotropy might originate from the CuO2 planes.Comment: 5 page

The Mean Ultraviolet Spectrum of a Representative Sample of Faint z~3 Lyman Alpha Emitters

We discuss the rest-frame ultraviolet emission line spectra of a large (~100) sample of low luminosity redshift z~3.1 Lyman alpha emitters (LAEs) drawn from a Subaru imaging survey in the SSA22 survey field. Our earlier work based on smaller samples indicated that such sources have high [OIII]/[OII] line ratios possibly arising from a hard ionising spectrum that may be typical of similar sources in the reionisation era. With optical spectra secured from VLT/VIMOS, we re-examine the nature of the ionising radiation in a larger sample using the strength of the high ionisation diagnostic emission lines of CIII]1909, CIV1549, HeII1640, and OIII]1661,1666 in various stacked subsets. Our analysis confirms earlier suggestions of a correlation between the strength of Ly-alpha and CIII] emission and we find similar trends with broad band UV luminosity and rest-frame UV colour. Using various diagnostic line ratios and our stellar photoionisation models, we determine both the gas phase metallicity and hardness of the ionisation spectrum characterised by xi_ion - the number of Lyman continuum photons per UV luminosity. We confirm our earlier suggestion that xi_ion is significantly larger for LAEs than for continuum-selected Lyman break galaxies, particularly for those LAEs with the faintest UV luminosities. We briefly discuss the implications for cosmic reionisation if the metal-poor intensely star-forming systems studied here are representative examples of those at much higher redshift.Comment: 15 pages, 9 figures. Accepted for publication in MNRA

A genome-wide investigation of the worldwide invader Sargassum muticum shows high success albeit (almost) no genetic diversity

Twenty years of genetic studies of marine invaders have shown that successful invaders are often characterized by native and introduced populations displaying similar levels of genetic diversity. This pattern is presumably due to high propagule pressure and repeated introductions. The opposite pattern is reported in this study of the brown seaweed, Sargassum muticum, an emblematic species for circumglobal invasions. Albeit demonstrating polymorphism in the native range, microsatellites failed to detect any genetic variation over 1,269 individuals sampled from 46 locations over the Pacific-Atlantic introduction range. Single-nucleotide polymorphisms (SNPs) obtained from ddRAD sequencing revealed some genetic variation, but confirmed severe founder events in both the Pacific and Atlantic introduction ranges. Our study thus exemplifies the need for extreme caution in interpreting neutral genetic diversity as a proxy for invasive potential. Our results confirm a previously hypothesized transoceanic secondary introduction from NE Pacific to Europe. However, the SNP panel unexpectedly revealed two additional distinct genetic origins of introductions. Also, conversely to scenarios based on historical records, southern rather than northern NE Pacific populations could have seeded most of the European populations. Finally, the most recently introduced populations showed the lowest selfing rates, suggesting higher levels of recombination might be beneficial at the early stage of the introduction process (i.e., facilitating evolutionary novelties), whereas uniparental reproduction might be favored later in sustainably established populations (i.e., sustaining local adaptation).Agence Nationale de la Recherche - ANR-10-BTBR-04; European Regional Development Fund; Fundacao para a Ciencia e a Tecnologia - SFRH/BPD/107878/2015, UID/Multi/04326/2016, UID/Multi/04326/2019; Brittany Region;info:eu-repo/semantics/publishedVersio

Multidisciplinary Projects: A Modern Technique in Engineering Education

The multidisciplinary project laboratory course has been developed for the purpose of preparing young engineers to deal successfully with the complex practical problems associated with todays\u27 technology. Students undertake a realistic engineering project which they pursue from inception to completion. Such a program fosters logical planning, ingenuity and creativity, constructive cooperation with related disciplines, technical responsibility, and a systematic approach to problem solving. The multidisciplinary project technique used in the Mechanical and Aerospace Engineering Department at Rutgers University is discussed in terms of a project example and benefits derived from the course

FARM COMMODITY PAYMENT LIMITS: WHAT IMPACT WILL THEY HAVE ON THE ECONOMIC VIABILITY OF SOUTHEASTERN AGRICULTURE?

Agricultural and Food Policy,

Nestling diet, secondary sexual traits and fitness in the zebra finch

We examined the effect of nestling diet quality on a suite of physiological, morphological and life-history traits in adult male zebra finches,Taeniopygia guttata. Compared with birds reared on a supplemented diet, nestlings reared on a seed-only diet showed a reduced rate of growth and reduced cell-mediated immune function as measured by an in vivo response to aT lymphocyte-dependent mitogen. There were no differences between birds reared on the two diets in any of the following adult traits: body size, primary sexual traits (testes mass, numbers of stored sperm, sperm function, velocity and morphology), secondary sexual traits (beak colour and song rate), serological traits or immunological traits. The only differences we detected were a lower body mass and a greater proportion of individuals with plumage abnormalities among those reared on a seed-only diet (this latter effect was transient). The fact that male zebra finches reared on a seed-only diet were, as adults, virtually indistinguishable from those reared on a supple- mented diet, despite having reduced growth and immune function as nestlings, demonstrates that they subsequently compensated through the di¡erential allocation of resources. Our results indicate that differ- ential allocation is costly in terms of fitness since birds reared on a seed-only diet experienced a significantly greater mortality rate than those reared on a supplemented diet. This in turn suggests the existence of a trade-of between the development of traits important for reproduction, such as primary and secondary sexual traits and longevity

Classical noise and flux: the limits of multi-state atom lasers

By direct comparison between experiment and theory, we show how the classical noise on a multi-state atom laser beam increases with increasing flux. The trade off between classical noise and flux is an important consideration in precision interferometric measurement. We use periodic 10 microsecond radio-frequency pulses to couple atoms out of an F=2 87Rb Bose-Einstein condensate. The resulting atom laser beam has suprising structure which is explained using three dimensional simulations of the five state Gross-Pitaevskii equations.Comment: 4 pages, 3 figure