Novel Diagnostic of Shock Fronts in Low-Z Dense Plasmas

We performed an experiment using high-energy protons to characterize in situ the spatial and temporal evolution of a laser-driven shock propagating through a low-Z material. Radiography of the shock propagating through the low-Z transparent material (Lexan, quartz, diamond) enabled estimation of density under compression. In order to discriminate the influence of the shocked matter on the protons trajectory, a Monte-Carlo simulation was developed. This code describes the protons trajectory through the matter, calculating the scattering angle and the loss of energy.     

Monica—A computer algorithm for solving boundary value problems using the double-hardening constitutive law Monot: I. Algorithm development

The principal features involved in the implementation of the double-hardening constitutive law Monot¹ into a general purpose computer algorithm called MONICA^2,3 are described. These include details of general program structure and of steps taken to overcome problems such as computer storage, computer run-time, algorithm stability and problems associated with the stress–strain singularity which exists at the intersection of the two yield surfaces.     

Hazard analysis of seismic submarine slope instability

To assess the risk associated with a submarine landslide, one must estimate the probability of slope failure and its consequences. This paper proposes a procedure to estimate the probability of earthquake-induced submarine slope failure (hazard) based on probabilistic seismic hazard analyses, ground response analyses and advanced laboratory tests. The outcomes from these analyses are treated in a probabilistic framework, with analytical simulations using mathematical techniques such as the first-order reliability method, Monte Carlo simulation and Bayesian updating. Fragility curves of slope failure during the earthquake (co-seismic) and after the earthquake (post-seismic) were developed in this study, and were shown to provide a clear and well-organized procedure to estimate the annual failure probability of a submarine slope under earthquake loading.     

Characterization of the near-Earth Asteroid 2002 NY40

In August 2002, the near-Earth Asteroid 2002 NY₄₀, made its closest approach to the Earth. This provided an opportunity to study a near-Earth asteroid with a variety of instruments. Several of the telescopes at the Maui Space Surveillance System were trained at the asteroid and collected adaptive optics images, photometry and spectroscopy. Analysis of the imagery reveals the asteroid is triangular shaped with significant self-shadowing. The photometry reveals a 20-h period and the spectroscopy shows that the asteroid is a Q-type.     

Socio-economic features of sea cucumber fisheries in southern coast of Kenya

A socio-economic assessment was conducted at Vanga, Shimoni, Majoreni and Gazi villages in the Kenyan south coast with focus on the sea cucumber fishing patterns, the social and economic characteristics of the fisher communities, the contribution of sea cucumbers to the local livelihoods, and analysis of the management systems. The results indicate that sea cucumber fishers are mainly men. Fishing is done in sub-tidal areas (3–10 m deep) and inter-tidal areas depending on the species being targeted. Those who fish in the sub-tidal areas do skin diving without using SCUBA diving gear. Sea cucumber fishing is heavily done during the northeast monsoon season when the sea is calm and water is clear. About 32% of the sea cucumber fishers also collect other marine products such as octopus. The sea cucumbers are sold fresh from the sea to local first level middlemen who process and sell them to the second level middlemen and exporters in Mombasa. The fishers occasionally borrow money from first level middlemen especially when they fail to catch sea cucumbers but this in turn creates conditions of dependence and possible exploitation. Almost all sea cucumber fishers have stated that they are not willing to make sea cucumbers part of their daily diet. The economic value of the product was substantial; the average monthly revenue for dry sea cucumbers in the area was estimated to US$ 8000. The relative highest profits are derived from juvenile species, thus there is an economic incentive hindering local stocks to reach sexual maturity, which in turn may create a situation in which recruitment success is highly dependent on faraway populations. The present management system falls into general fisheries regulations and was found weak. No specific management plan for sea cucumbers was found.     

Runoff generation mechanisms in pastures of the Sand Mountain region of Alabama—a field investigation

Excessive application of poultry litter to pastures in the Sand Mountain region of north Alabama has resulted in phosphorus (P) contamination of surface water bodies and buildup of P in soils of this region. Since surface runoff is recognized as the primary mechanism of P transport, understanding surface runoff generation mechanisms are crucial for alleviating water quality problems in this region. Identification of surface runoff generation mechanisms is also important for delineation of hydrologically active areas (HAAs). Therefore, the specific objective of this study was to identify surface runoff generation mechanisms (infiltration excess versus saturation excess) using distributed surface and subsurface sensors and rain gauge. Results from three rainfall events (2·13–3·43 cm) of differing characteristics, and sensor data at four locations with differing soil hydraulic properties along the hillslope showed that the main surface runoff generation mechanism in this region is infiltration excess. Because of this, rainfall intensity and soil hydraulic conductivity were found to play dominant roles in surface runoff generation in this region. Further, only short periods of a few rainfall events during which the rainfall intensity is high produce surface runoff. This study indicates that perhaps subsurface flows and transport of P in subsurface flows need to be quantified to reduce P contamination of surface water bodies in this region. Current studies at this location are identifying spatial and temporal distribution of HAAs, quantifying rainfall characteristics that generate runoff, and estimating runoff volume that results from connected HAAs. Copyright © 2008 John Wiley & Sons, Ltd.     

Elemental composition from gamma‐ray spectroscopy of the NEAR‐Shoemaker landing site on 433 Eros

Abstract— Elemental composition and composition ratios derived from gamma‐ray measurements collected by the NEAR‐Shoemaker spacecraft while on the surface of 433 Eros are reported. Performance of the gamma‐ray spectrometer (GRS) during cruise and orbit is reviewed. The best gamma‐ray data were collected on the surface of Eros after the spacecraft's controlled descent on 2001 February 12. Methods used in spectral analysis, to convert peak areas to incident photons, and photons to elemental composition are described in some detail. The elemental abundance of K and the Mg/Si, Fe/Si, Si/O and Fe/O abundance ratios were determined. The Mg/Si and Si/O ratios and the K abundance are roughly chondritic, but the Fe/Si and Fe/O ratios are low compared to expected chondritic values. Three possible explanations for the apparent Fe depletion are considered.