Bulletin of Engineering Geology and the Environment - This present paper presents an adopted methodology for Micro Tunnel Boring Machine (TBM) selection, based on the results of a... 相似文献
DROUGHT AND FAMINE IN ETHIOPIA Editor: Abdul Mejid Hussein. African Environment Special Report No. 2, The International African Institute, London, 1976,121 pp. £1.50.
HEDGING (A Practical conservation handbook) Alan Brooks, The British Trust for Conservation Volunteers, The Zoological Gardens, Regents Park, London, 1975. 117 pp. £2.10 inc. postage.
THREE JOURNALS Habitat: Published by : The Council for Nature, The Zoological Gardens, Regents Park, NW1 4RY. At £2.50, or £5.00 per annum.
Recreation News: Published by: The Countryside Commission , John Dower House, Crescent Place, Cheltenham, Glos., GL50 3RA.
The International Journal of Environmental Studies: Published by : Gordon Breach Science Publishers Ltd., 42 William IV Street. London, W.C.2. £17.50 for individuals, £35.00 for Libraries. Habitat
A HISTORY OF LANCASHIRE J.J. Bagley, Phillimore & Co. Ltd., London & Chichester 1976. 128 pp. £4.95. 相似文献
Land-cover (LC) products, especially at the regional and global scales, comprise essential data for a wide range of environmental studies affecting biodiversity, climate, and human health. This review builds on previous compartmentalized efforts by summarizing 23 global and 41 regional LC products. Characteristics related to spatial resolution, overall accuracy, time of data acquisition, sensor used, classification scheme and method, support for LC change detection, download location, and key corresponding references are provided. Operational limitations and uncertainties are discussed, mostly as a result of different original modelling outcomes. Upcoming products are presented and future prospects towards increasing usability of different LC products are offered. Despite the common realization of product usage by non-experts, the remote-sensing community has not fully addressed the challenge. Algorithmic development for the effective representation of inherent product limitations to facilitate proper usage by non-experts is necessary. Further emphasis should be placed on international coordination and harmonization initiatives for compatible LC product generation. We expect the applicability of current and future LC products to increase, especially as our environmental understanding increases through multi-temporal studies. 相似文献
Policy-based management provides the ability to (re-)configure differentiated services networks so that desired Quality of Service (QoS) goals are achieved. This requires implementing network provisioning decisions, performing admission control, and adapting bandwidth allocation to emerging traffic demands. A policy-based approach facilitates flexibility and adaptability as policies can be dynamically changed without modifying the underlying implementation. However, inconsistencies may arise in the policy specification. In this paper we provide a comprehensive set of QoS policies for managing Differentiated Services (DiffServ) networks, and classify the possible conflicts that can arise between them. We demonstrate the use of Event Calculus and formal reasoning for the analysis of both static and dynamic conflicts in a semi-automated fashion. In addition, we present a conflict analysis tool that provides network administrators with a user-friendly environment for determining and resolving potential inconsistencies. The tool has been extensively tested with large numbers of policies over a range of conflict types. 相似文献
A combined experimental, analytical and numerical study of sheeting of wheat flour dough was performed. The material behaviour was defined using a non‐linear viscoelastic model calibrated with data obtained from uniaxial compression, loading–unloading and stress relaxation tests. Tests were performed using an instrumented small‐scale rolling rig. The roll speed and roll gap were varied to determine the effect on the steady‐state vertical force and exit thickness. Experiments were performed using one‐stand as well as a two‐stand roll set up. The analytical model which assumed perfect plasticity led to significantly lower forces than the experimental data. The numerical predictions were accurate at small reduction ratios. The exit thickness of the dough sheet was predicted accurately from the numerical model. For the two‐stand rolling, the numerical data were not accurate when a significant level of stress developed in the dough between the two roll stands. 相似文献
The tensile properties of latex coatings were investigated with a set of custom formulated artist-type paints at an age of 1 year. All films in the study contained a poly(methyl methacrylate-cobutyl acrylate) binder exhibiting a glass-transition at approximately 10 °C. The viscoelastic behaviour of the latex matrix is first highlighted through a series of experiments involving different strain histories and temperatures. Influence of the inorganic particle concentration and geometry is then illustrated using TiO2 and calcined kaolin for the secondary phase. Experimental data from a wide range of conditions are summarised through master curves of secant modulus and failure strains using time–temperature superposition. The results indicate that the latex films behave in a rheologically simple manner and it is possible to predict the response outside of the experimental time-scale. An analysis by similar methods is also given for TiO2 pigmented films with/without surfactant removed by immersion in water. Differential scanning calorimetry and atomic force microscopy were also used in conjunction with mechanical tests. The combined findings suggest that a fraction of surfactant migrates to the TiO2 interface during film formation, where it interferes with adhesion of the acrylic matrix. 相似文献
The design of tunnels and slopes in heterogeneous rock masses such as flysch presents a major challenge to geologists and
engineers. The complex structure of these materials, resulting from their depositional and tectonic history, means that they
cannot easily be classified in terms of widely used rock mass classification systems. A methodology for estimating the Geological
Strength Index and the rock mass properties for these geological formations is presented in this paper.
Electronic Publication 相似文献
The tensile properties of latex paint films containing TiO2 pigment were studied with respect to temperature, strain-rate and moisture content. The purpose of performing these experiments
was to assist museums in defining safe conditions for modern paintings held in collections. The glass transition temperature
of latex paint binders is in close proximity to ambient temperature, resulting in high strain-rate dependence in typical exposure
environments. Time dependence of modulus and failure strain is discussed in the context of time–temperature superposition,
which was used to extend the experimental time scale. Nonlinear viscoelastic material models are also presented, which incorporate
a Prony series with the Ogden or Neo-Hookean hyperelastic function for different TiO2 concentrations. 相似文献
Determination of turbidity is a common component of water-quality assessments. In regions where there are a lot of inland
waters such as dams, sampling even a small proportion of those dams for monitoring and assessing water quality is cost prohibitive.
Satellite remote sensing has the potential to be a powerful tool for assessing water quality over large spatial scales. The
overall objective of this study was to examine whether Landsat-5 TM (Thematic Mapper) and Landsat-7 ETM+ (Enhanced Thematic
Mapper) could be used to measure turbidity across theKourris Dam, which is the biggest dam in Cyprus. This paper presents
the results obtained by applying the linear regression analysis in order to examine the relationship between the turbidity
measurements measured in-situ during the satellite overpass against at-satellite atmospheric corrected reflectance values.
It has been found that the reflectance, after atmospheric correction, at LandsatTMBands 1 and 3 is strongly related with turbidity
levels after linear regression analysis. The most significant correlation was occurred when reflectance in TM band 3 and logarithmic
reflectance in TM band 3 were correlated with turbidity measurements. Indeed, the correlation coefficient (R) when atmospheric
corrected reflectance (ρ) in the LandsatTMband 3 were correlated against turbidity, before atmospheric correction was R =
0.38 and after atmospheric correction was R = 1; and when atmospheric corrected logarithmic reflectance (Log ρ) in the Landsat
TM band 3 were correlated against turbidity, before atmospheric correction was R = 0.46 and after atmospheric correction was
R = 1. 相似文献