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481.
Labidi S Dachraoui M Mahjoubi H Lemaitre N Salah RB Mtimet S 《Journal of environmental radioactivity》2002,62(1):87-96
Radioactivity in some Tunisian thermo-mineral springs (11 hot mineral springs and one cold spring) has been determined for the first time in Tunisia using radiochemical separation procedures. The obtained results show that 238U activity concentrations vary between 1.5 and about 43 mBq/l. The measured activities of 234U and 226Ra range from 1.1 to about 82.2 mBq/l and 34-3,900 mBq/l. respectively. The radioactive disequilibria in these waters are in excess of concentration of 234U compared to that of 238U. The 226Ra/234U activity ratios are high and in the range of 9.0-691.0). U, Th and Ra activities are similar to those published for other non-polluted regions of the world. Radioactivity in the only cold mineral water from A?n Oktor is very low, and thus health hazards due to the consumption of this water are not expected. 相似文献
482.
V.?Krishna?PrasadEmail author Ben?Stinner Deb?Stinner John?Cardina Richard?Moore Prabhat?K.?Gupta Harao?Tsuruta Kiyoto?Tanabe K.?V.?S.?Badarinath Casey?Hoy 《Regional Environmental Change》2003,3(4):154-161
We studied trends in food production and nitrous oxide emissions from India's agricultural sector between 1961 and 2000. Data
from Food and Agricultural Statistics (FAO) have been gathered covering production, consumption, fertilizer use and livestock
details. IPCC 1996 revised guidelines were followed in studying the variations in N2O-N emissions. Results suggest that total N2O-N emissions (direct, animal waste and indirect sources) increased ~6.1 times from ~0.048 to ~0.294 Tg N2O-N, over 40 years. Source-wise breakdown of emissions from 1961–2000 indicated that during 1961 most of the N2O-N inputs were from crop residues (61%) and biological nitrogen fixation (25%), while during 2000 the main sources were synthetic
fertilizer (~48%) and crop residues (19%). Direct emissions increased from ~0.031 to ~0.183 Tg. It is estimated that ~3.1%
of global N2O-N emissions comes from India. Trends in food production, primarily cereals (rice, wheat and coarse grains) and pulses, and
fertilizer consumption from 1961–2000 suggest that food production (cereals and pulses) increased only 3.7 times, while nitrogenous
fertilizer consumption increased ~43 times over this period, leading to extensive release of nitrogen to the atmosphere. From
this study, we infer that the challenge for Indian agriculture lies not only in increasing production but also in achieving
production stability while minimizing the impact to the environment, through various management and mitigation options. 相似文献
483.
Compared to other continents, the economic growth performance of Sub-Saharan Africa has been poor over the last four decades. Likewise, progress in agricultural development has been limited and the Green Revolution left Africa almost untouched. The question raised in the literature is whether the poor performance is a question of poor policies or of an unfavorable biophysical environment (policy versus destiny). This paper, with a broad perspective, analyzes adaptation of current land use to environmental conditions in Africa and compares the physical resource base of Africa with Asia. In doing so, we search for unifying principles that can have operational consequences for agricultural development. We argue that some specificities of the natural resource base, namely local homogeneity and spatial diversity of the predominant Basement Complex soils, imply that simple fertilizer strategies may not produce the yield increases obtained elsewhere. 相似文献
484.
Kate Millar Erik Thorstensen Sandy Tomkins Ben Mepham Matthias Kaiser 《Journal of Agricultural and Environmental Ethics》2007,20(1):53-63
A number of EU institutions and government committees across Europe have expressed interest in developing methods and decision-support
tools to facilitate consideration of the ethical dimensions of biotechnology assessment. As part of the work conducted in
the EC supported project on ethical tools (Ethical Bio-TA Tools), a number of ethical frameworks with the potential to support
the work of public policy decision-makers has been characterized and evaluated. One of these potential tools is the Delphi
method. The Delphi method was originally developed to assess variables that are intangible and/or shrouded in uncertainty
by drawing on the knowledge and abilities of a diverse group of experts through a form of anonymous and iterative consultation.
The method has hitherto been used by a diversity of practitioners to explore issues such as technology assessment, environmental
planning, and public health measures. From the original (classical) Delphi, a family of Delphi-related processes has emerged.
As a result of the evaluation of the various Delphi processes, it is proposed that the classical method can be further developed
and applied as a form of ethical framework to assist policy-makers. Through a series of exercises and trials, an Ethical Delphi
has been developed as a potential approach for characterizing ethical issues raised by the use of novel biotechnologies. Advantages
and disadvantages of the method are discussed. Further work is needed to develop the procedural aspects of the Ethical Delphi
method and to test its use in different cultural contexts. However, utilizing an ethical framework of this type combines the
advantages of a methodical approach to capture ethical aspects with the democratic virtues of transparency and openness to
criticism. Ethical frameworks such as the Ethical Delphi should contribute to better understanding of and decision-making
on issues that involve decisive ethical dimensions. 相似文献
485.
John C. Whitehead Ben Poulter Christopher F. Dumas Okmyung Bin 《Mitigation and Adaptation Strategies for Global Change》2009,14(8):777-792
In this paper we develop estimates of the economic effects of sea level rise on marine recreational shore fishing in North Carolina, USA. The relationship between angler behavior and spatial differences in beach width is estimated using the Marine Recreational Fishing Statistics Survey and geospatial data. We exploit the empirical relationship between beach width and fishing site choice by simulating the effects of sea level rise on angler site choice. We find that reductions in beach width negatively affect the quality and number of fishing trips even as anglers adapt by using piers and bridges. Welfare losses are potentially substantial, ranging up 39% of the total value of marine shore fishing in North Carolina. 相似文献
486.
Ben T. Hirsch 《Behavioral ecology and sociobiology》2011,65(4):581-591
The location of an animal within a social group has important effects on feeding success. When animals consume quickly eaten
food items, individuals located at the front edge of a group typically have greater foraging success. When groups feed at
large clumped resources, dominant individuals can often monopolize the resource, leading to higher feeding success in the
center of the group. In order to test these predictions, behavioral data relating foraging success to within-group spatial
position were recorded from two habituated groups of ring-tailed coatis (Nasua nasua) in Iguazu, Argentina. Foraging success did not fit expected patterns. When feeding on small ground litter invertebrates,
coatis had the same foraging success at all spatial positions. This pattern likely resulted from an abundance of invertebrates
in the ground litter. When feeding on fruit, individuals in the front of the group had greater feeding success, which was
driven by the relatively quick depletion of fruit trees. Dominant juveniles were often located in the front of the group which
led to increased access to food. This resulted in higher feeding success on fruits but simultaneously increased their risk
of predation. Although groups typically became more elongated and traveled faster when feeding on fruit, it did not appear
that the coatis were drastically changing their spacing strategies when switching between the two food types. Paradoxically,
spatial position preferences during invertebrate foraging appeared to be driven by fruit trees. Because fruit trees were encountered
so frequently, juveniles ranging at the front edge of the group during invertebrate foraging were the first to arrive at fruit
trees and thus had higher foraging success. This study demonstrates the importance of how food patch size and depletion rate
affect the spatial preferences of individuals. 相似文献
487.
为了对存在热失控危险的硝基苯精馏装置爆炸事故因素进行研究,利用RSD快速筛选量热仪,对硝基苯精馏塔中存在的主要危险物质(硝基苯、二硝基苯和二硝基酚钠盐)进行试验测试,筛选出最危险物质.在获得主要危险物反应质热失控的基础数据条件下,对二硝基酚钠与硝基苯间不同比例的复配物进行热分析测试.研究表明:在相同的操作条件下,二硝基酚钠盐有放热反应,纯物质硝基苯和二硝基苯在测试条件下较稳定,没有放热现象;当二硝基酚钠盐与硝基苯复配后在试验过程中有强放热反应,存在较大的热失控风险. 相似文献
488.
Karoui Sarra Ben Arfi Rim Fernández-Sanjurjo María J. Nuñez-Delgado Avelino Ghorbal Achraf Álvarez-Rodríguez Esperanza 《Environmental science and pollution research international》2021,28(34):46431-46447
Environmental Science and Pollution Research - The first aim of this study was to synthesize and characterize reed-based-beads (BBR), an enhanced adsorbent from Tunisian reed. The second purpose... 相似文献
489.
Guiza Khawla Ben Arfi Rim Mougin Karine Vaulot Cyril Michelin Laure Josien Ludovic Schrodj Gautier Ghorbal Achraf 《Environmental science and pollution research international》2021,28(34):46655-46668
Environmental Science and Pollution Research - Keratin/cellulose cryogels were successfully fabricated using chicken feathers (CF) and cardboard (C) from environmental waste for the first time, to... 相似文献