A radiation belt monitor for the high energy transient experiment satellite

A Radiation Belt Monitor (RBM) sensitive to protons and electrons with energy 0.5 MeV¹ has been designed for the High Energy Transient Experiment (HETE) satellite in order to: first, control the on-off configuration of the experiments (i.e. those susceptible to proton damage); and second, to indicate the presence of proton and/or electron events that could masquerade as legitimate high energy photon events. One of the two RBM channels has an enhanced sensitivity to electrons. Each channel of the RBM, based on a PIN silicon diode, requires a typical power of 6 milliwatts. Tests have been performed with protons with energies from 0.1 to 2.5 MeV (generated by a Cockcroft-Walton linear accelerator via the d(d,p)t reaction), and with electrons with energies up to 1 MeV (from a 1.0 µCi²⁰⁷Bi source).     

If Quebec Goes . . . The ‘Exodus' Impact?

In this paper, we explore migration aspects of the 1995 Quebec Sovereignty Referendum with data from a survey administered to non-francophones in Montreal two weeks prior to the Referendum. While the Quebec sovereignty issue has been around for some time and earlier exodus from the province, particularly among anglophones, is largely regarded as “forced” in some way, this study neither confirms the 1995 Sovereignty Referendum as a paramount factor in explaining outmigration from Quebec nor points to a real reluctance to leave Montreal. The decision to move is influenced by the interplay of a multitude of factors. The political influence is only an added factor to longstanding economic decline and cultural clash. Moreover, if there is any impulsion, the degree varies among different cultural and socioeconomic groups.     

The dynamics of rupture in porous media

This paper presents a laboratory investigation of electric resistivity parameter for samples subject to loading in automatic press of INOVA type. The procedure of automatic quasi-continuous measurements of resistivity is briefly outlined. The distribution of mini-electrodes within the sample is described. Also shown is the manner in which reliability can be improved by increasing the repetition of resistivity measurements (every 7–16 s).     

Plio-Pleistocene geological evolution of the northern Sicily continental margin (southern Tyrrhenian Sea): new insights from high-resolution,multi-electrode sparker profiles

High-resolution seismic profiles were acquired in the north Sicily offshore region with an innovative, multi-tip sparker array which lacks ringing and has a base frequency around 600 Hz. The new data, combined with published data, suggest that intra-slope and extensional basins formed as a consequence of the late Miocene (?)–early Pliocene shortening and thrusting, and the middle (?)–late Pliocene continental rifting affecting the internal side of the Sicilian-Maghrebian chain. Early (?) Pleistocene to Holocene high-amplitude and high-frequency sea-level changes resulted in repeated sub-aerial exposure and flooding of the shelf, and the deposition of cyclically arranged hemipelagic and shelf sediments. An uplift of the shelf could explain the non-preservation of the transgressive and of the lowstand wedge systems tracts in the oldest sequences.     

Internal soil moisture response to rainfall-induced slope failures and debris discharge

Predictions of rainfall-induced fast-moving mass flow and/or debris flows require better knowledge of the mechanism controlling the debris discharge of slopes in debris source areas. A series of rainfall tests on 0.32 m-deep, 0.7 m-high, 1.35 m-wide sandy slopes resting on a bi-linear impermeable rigid base was performed. Soil moisture content and solid discharge measurements were performed to gain insights into the rainfall-induced retrogressive slope failure. The solid (or debris) discharge is a result of the wash-out of the fluidized slope toe by the interflow along the soil–bedrock interface. Characteristics of the failure process for the slopes are represented by mass wasting curves or ‘solid discharge (Q_s) vs. time (t)’ curves which are functions of the rainfall intensity and/or the cumulative rainfall. The mass wasting curves have inflection points representing transitions from minor toe failures into remarkable retrogressive failures. The first inflection point of the soil moisture (ω) vs. t curve measured at the soil–bedrock interface signaling the arrival of the descending ‘wet front’, may serve as a precursor for predicting the onset of an abrupt solid discharge induced by shallow slope failures. The time of peak water content measured at the soil–bedrock interface may approximate the time of 5% total solid volume discharge. Up to the time of 5% of total slope volume discharge, a fully saturated state (S_r  100%) was never observed at the 0.2 m-below-surface zone; however, it was observed along the soil–bedrock interface at near-toe zone of the slope, regardless of the intensity of rainfall investigated. Retrogressive failures were essentially associated with nonuniformly distributed water content in the slope. For both the 0.2 m-below-surface zone and the soil–bedrock interface, a more uniform distribution of S_r along the full height of the slope was found for slopes subjected to high rainfall intensities of 47 and 65 mm/h than that for the slope subjected to a low rainfall intensity of 23 mm/h. At the inflection point of the Q_s vs. t curve and 5% of total solid volume discharge, values of S_r at a certain distance from the toe for the soil–bedrock interface were higher than those measured at the same distance from the toe for the 0.2 m-below-surface zone, indicating the effect of infiltration-induced interflow along the soil–bedrock interface and its effects on the fluidization of the slope toe and the retrogressive failure of the slope.     

Kinematic model of a translational slide in the Cidu section of the Formosan Freeway

This study presents a kinematic model of a translational slide in the Cidu section of the Formosan Freeway in Taiwan, including the associated kinematic processes and the geometry of the deposition. A numerical simulation of the slide was performed using the discrete element method. This kinematic model has been considered the distribution of bedding plane and joints, engineering installations, and mechanical parameters in the development of a numerical model capable of clarifying the kinematic characteristics of this translational slide with high velocities. When the friction coefficient of each particle was set to 0.03, the predicted maximum velocity was 23.6 m/s and the debris reached the other side of the Formosan Freeway. The simulations demonstrated that the three cars involved in the incident and the Formosan Freeway itself were buried at 2 to 4 s during the event (the predicted average velocity was 10.2 m/s) and that the translational slide ceased its movement at 7.5 s, resulting in the formation of a slightly fragmented depositional mass.     

The atmospheric temperature in Italy during the last one hundred years and its relationships with solar output

Summary We analyze surface air temperature historical data with a principal focus on the last one hundred years and on the Italian territory. We find, using only statistical methods that this area can be divided in two climatically homogeneous zones: in both of these zones we find a positive temperature trend for the last one hundred years. This trend is always steeper for the winter temperatures and more pronounced for northern than for southern stations. In the historical temperature series power spectrum we identify two broad significant peaks, one containing the well known quasi-biennial oscillation and the other either solar periodicity related to the inversion of the sun magnetic polarity (Hale cycle) or the North Atlantic ocean-atmosphere oscillation.With 7 Figures     

PARALLAX BAR HEIGHT MEASUREMENTS FROM LARGE FORMAT CAMERA PHOTOGRAPHY

The accuracy of heighting from Large Format Camera (LFC) stereo-photographs of the New England area was evaluated using a conventional mirror stereoscope equipped with × 6 binocular eyepieces and a precision parallax bar. It was discovered that a large differential ω had to be removed before acceptable height results could be obtained. Enlarged portions of the LFC photographs covering city areas of Boston, Massachusetts and Providence, Rhode Island could be used to produce accurate height results. It was concluded that analogue mapping from LFC photography using simple instruments could be economically carried out at a scale of 1:100000 or smaller, with a contour interval of 100 m to 120 m.     

On the determination of zero-plane displacement and roughness length for flow over forest canopies

This paper discusses the importance of the aerodynamic characteristics of forest and other similar canopies to modelling of boundary-layer flow and to estimating the diffusivity coefficients of turbulence transfer mechanisms over such canopies.The hypothesis of Marunich (1971) reported by Tajchman (1981) that the zero-plane displacement, d, equals the upward displacement of the flow trajectory, is critically examined. It is concluded that Marunich's hypothesis is conceptually incorrect and that calculations of d based on Marunich's hypothesis are inherently in error.This paper presents a method based on the mass conservation principle and uses wind profiles in and above a forest canopy as the sole input for determining d, z ₀ and u _*.Sensitivities of calculated results to measurements errors of wind profile data are evaluated. It is found that an error of less than 1% in wind in the logarithmic regime above the canopy can introduce up to 100% errors in calculated values of d, z ₀ and u _*. It is also found that the high sensitivity to wind data accuracy, characteristic of the present method, can be used as a guide for the selection of high quality canopy wind data.