The rhythms of shipboard life: work, hierarchy, occupational culture and multinational crews

Several words repeatedly crop up when you ask a seafarer working in the international cargo fleet to describe a life at sea: ‘boring’, is one; ‘lonely’ is another; and the word ‘sacrifice’ is used very frequently as well. Most contemporary seafarers are recruited from developing economies where well-paid opportunities for work ashore are scarce and, if they can be found at all, are only available to highly skilled or qualified personnel. As a result, the money that can be earned at sea by both officers and ratings is often unparalleled and this encourages people to seek work as a seafarer when they are young. It also keeps many of them coming back to sea as they get older (as described so vividly by Baum-Talmor in Chap. 5) despite having come to grips with some of the rather unglamorous aspects of the job

UV and X-ray Spectral Lines of FeXXIII Ion for Plasma Diagnostics

We have calculated X-ray and UV spectra of Be-like Fe (FeXXIII) ion in collisional-radiative model including all fine-structure transitions among the 2s^2, 2s2p, 2p^2, 2snl, and 2pnl levels where n=3 and 4, adopting data for the collision strengths by Zhang & Sampson (1992) and by Sampson, Goett, & Clark (1984). Some line intensity ratios can be used for the temperature diagnostics. We show 5 ratios in UV region and 9 ratios in X-ray region as a function of electron temperature and density at 0.3keV < T_e < 10keV and $n_e = 1 - 10^{25} cm^{-3}$. The effect of cascade in these line ratios and in the level population densities are discussed.Comment: LaTeX, 18 pages, 10 Postscript figures. To appear in Physica Script

The GREAT triggerless total data readout method

Recoil decay tagging (RDT) is a very powerful method for the spectroscopy of exotic nuclei. RDT is a delayed coincidence technique between detectors usually at the target position and at the focal plane of a spectrometer. Such measurements are often limited by dead time. This paper describes a novel triggerless data acquisition method, which is being developed for the Gamma Recoil Electron Alpha Tagging (GREAT) spectrometer, that overcomes this limitation by virtually eliminating dead time. Our solution is a total data readout (TDR) method where all channels run independently and are associated in software to reconstruct events. The TDR method allows all the data from both target position and focal plane to be collected with practically no dead-time losses. Each data word is associated with a timestamp generated from a global 100-MHz clock. Events are then reconstructed in real time in the event builder using temporal and spatial associations defined by the physics of the experimen

The ROTSE-III Robotic Telescope System

The observation of a prompt optical flash from GRB990123 convincingly demonstrated the value of autonomous robotic telescope systems. Pursuing a program of rapid follow-up observations of gamma-ray bursts, the Robotic Optical Transient Search Experiment (ROTSE) has developed a next-generation instrument, ROTSE-III, that will continue the search for fast optical transients. The entire system was designed as an economical robotic facility to be installed at remote sites throughout the world. There are seven major system components: optics, optical tube assembly, CCD camera, telescope mount, enclosure, environmental sensing & protection and data acquisition. Each is described in turn in the hope that the techniques developed here will be useful in similar contexts elsewhere.Comment: 19 pages, including 4 figures. To be published in PASP in January, 2003. PASP Number IP02-11

Excitation of the 3.071mm Hyperfine Line in Li-Like 57-Fe in Astrophysical Plasmas

As noted first by Sunyaev & Churazov (1984), the 3.071 mm hyperfine line from $^{57}Fe^{+23}$ might be observable in astrophysical plasmas. We assess the atomic processes which might contribute to the excitation of this line. We determine the intensity of the hyperfine line from an isothermal, coronal plasma in collisional ionization equilibrium and for a coronal plasma cooling isobarically due to its own radiation. Comparisons of the hyperfine line to other lines emitted by the same ion, Fe$^{+23}$, are shown to be useful for deriving the isotopic fraction of $^{57}$Fe. We calculate the ratios of the hyperfine line to the 2s--2p EUV lines at 192 \AA and 255 \AA, and the 2s--3p X-ray doublet at 10.6 \AA.Comment: 28 pages text+figures, Accepted to ApJ in Jan 98, also at http://www.astro.virginia.edu/~nld2n/research.htm

Utilización de modelos de reflectancia como nexo entre muestras foliares y la cobertura forestal: aplicación a datos hiperespectrales

[ES] El presente trabajo demuestra la utilización de modelos de simulación de la cobertura forestal mediante su aplicación a datos hiperespectrales del sensor aerotransportado CASI. Los modelos SAIL y Kuusk permiten ser utilizados como nexo de unión entre los niveles de hoja y de cobertura: las relaciones a nivel de hoja obtenidas entre índices ópticos y bioindicadores de estrés, como contenido clorofílico o fluorescencia clorofílica, pueden ser transformadas a un nivel superior de cobertura mediante la utilización de dichos modelos. Finalmente se realiza una demostración de la utilización de modelos de cobertura a través de los resultados obtenidos en el proyecto Bioindicators of Forest Sustainability, desarrollado en 12 zonas de Acer saccharum M. localizadas en Ontario (Canadá) donde se obtuvieron medidas de campo de muestras foliares, así como datos hiperespectrales del sensor aerotransportado CASI en 1997, 1998 y 1999. Los indices ópticos desarrollados a nivel de hoja fueron aplicados, a través de modelos de cobertura, a los datos de reflectancia obtenidos por CASI de 2 m de resolución espacial y 72 bandas[EN] This paper demonstrates the use and applications of Canopy Reflectance Models (CR) with airborne hyperspectral CASI data. SAIL and Kuusk canopy reflectance models are the link between the leaf and canopy levels: leaf-level relationships obtained between optical indices and stress bioindicators, such as chlorophyll content and chlorophyll fluorescence can be scaled-up to the canopy level using canopy reflectance models. The application of canopy reflectance models is demonstrated with the results obtained in the Bioindicators of Forest Sustainability Project. The work was carried out in 12 study areas of Acer saccharum M. in the Algoma Region, Ontario (Canada), where field measurements and hyperspectral CASI imagery have been collected in 1997, 1998 and 1999 deployments. Single leaf reflectance and transmittance, chlorophyll and carotenoid content, and chlorophyll fluorescence of broad leaves were measured. The physiological indices and derivative analysis indices extracted from leaf spectral reflectance were tested at canopy level using CASI data of 72 channels and 2 m spatial resolution.Peer reviewe