137 research outputs found
Soil properties of bare patches in rangelands of South African's grasslands
A loss of grassy cover accompanied by the development of bare soil patches, are the most notable forms of rangeland degradation in grasslands of South Africa. Concerns are growing over the threat of loss of nutritious perennial grass species and the lack of regrowth of the bare patches. Grazing and different rangeland tenure systems -communal and freehold, which is equal to continuous and rotational grazing system - are considered to be of major importance for rangeland degradation. The continuous grazing system is seen to be more affected, but the development of bare patches is not restricted to communal land. We hypothesized that (1) soil properties of bare patches in South AfricaÂŽs grasslands are not different in different tenure systems, and (2) soil properties differ with size of bare patches, where big patches are more degraded.
To test this, we sampled soils at communal and commercial land in the Thaba Nchu area of South Africa with the following design: we selected three farms per tenure system, 6 randomly chosen plots (100x100m) per farm, and within these plots we sampled 5 bare patches of different sizes (0-10 cm) per plot, where the soil sample (3 replicates) were taken out of the middle of the bare patch. Additionally, soils of adjacent grass were sampled. The results showed that in total, there were more bare patches in continuous grazing systems, evaluated by aerial pictures, but we couldnÂŽt find any differences in bulk density and carbon stocks, between the tenure systems. Additionally, and surprisingly, we found no significant differences in soil organic carbon stocks between bare soil samples and grass samples. There was no clear relationship between bare patch size and nutrient contents. Other nutrients like phosphor were significantly enlarged at the bare patch compared to the grass samples. According to our results, we conclude, that the bare patches seem to develop in different pathways: i) along tracks of grazing animals, (ii) around termite hills, where the termite construction seems to be an initial starting point of bare patches and (iii) on staying and lying places of the grazing animals, which aslo explain the higher nutrient contents at the bare patches
Morphology of the southern African geomagnetic field derived from observatory and repeat station survey observations: 2005â2014
Collectivity, Phase Transitions and Exceptional Points in Open Quantum Systems
Phase transitions in open quantum systems, which are associated with the
formation of collective states of a large width and of trapped states with
rather small widths, are related to exceptional points of the Hamiltonian.
Exceptional points are the singularities of the spectrum and eigenfunctions,
when they are considered as functions of a coupling parameter. In the present
paper this parameter is the coupling strength to the continuum. It is shown
that the positions of the exceptional points (their accumulation point in the
thermodynamical limit) depend on the particular type and energy dependence of
the coupling to the continuum in the same way as the transition point of the
corresponding phase transition.Comment: 22 pages, 4 figure
A critique of the Global Pact for the Environment: A stillborn initiative or the foundation for Lex Anthropocenae?
In May 2018 the process which may ultimately lead to the negotiation of a legally binding Global Pact for the Environment formally commenced under the auspices of the United Nations General Assembly. Expectations for the Pact are high, evidenced in particular by its multiple and overlapping objectives: to serve as a generic binding instrument of international environmental law (IEL) principles ; to integrate, consolidate, unify and ultimately entrench many of the fragmented principles of IEL; and to constitute the first global environmental human rights instrument. In the wake of the impending intergovernmental process, the paper offers a thorough critique of the draft Pact in its present iteration. We do so with the aim of evaluating the strengths and weaknesses of the present draft Pact by interrogating: a) its diplomatic and symbolic relevance and possible unique contribution at the policy level to global environmental law and governance; and b) its potential at the operational level of IEL and global environmental governance, focusing on the extent to which the draft Pact accommodates both existing and more recent rules and principles for environmental protection. As the Pactâs primary ambition is to become a universally binding global treaty, it would be churlish not to recognise its potential for innovation, as well as the considerable opportunity that the negotiation of the Pact will have to generate broad-sweeping and positive impacts. However, our central thesis is that only if the Global Pact were to incorporate ambitious normative provisions to strengthen those public and private global governance efforts that aim to halt the deterioration of Earth system integrity, as well as to maintain and improve integrity, will it be able to offer a firm foundation of the type of Anthropocene Law, termed here as the Lex Anthropocenae, required to confront head-on the deep socio-ecological crisis of the Anthropocene
Improving the Performance in Occupational Health and Safety Management in the Electric Sector: An Integrated Methodology Using Fuzzy Multicriteria Approach
The electric sector is fundamental for the economic and social development of society, impacting on essential aspects such as health, education, employment generation, industrial production, and the provision of various services. In addition to the above, the growing trend in energy consumption worldwide could increase, according to expert estimates, up to 40% by 2030, which in turn increases the efforts of the public and private sector to meet increasing demands and increase access to energy services under requirements of reliability and quality. However, the electricity sector presents challenges and complexities, one of which is the reduction of health and safety risks for workers, service users, and other stakeholders. In many countries, this sector is classified as high risk in occupational safety and health, due to its complexity and the impact of accidents and occupational diseases on the health of workers, in infrastructure, in operating costs and competitiveness of the energy sector. Worldwide, there are rigorous regulations for the electricity sector, from local and national government regulations to international standards to guarantee health and safety conditions. However, it is necessary to develop objective and comprehensive methodologies for evaluating occupational safety and health performance that provides solutions for the electricity sector, not only to comply with standards and regulations also as a continuous improvement tool that supports the decision-making processes given the complexity of the industry and the multiple criteria that are taken into account when evaluating and establishing improvement strategies. In scientific literature, different studies focus on the analysis of accident statistics, the factors that affect accidents and occupational diseases, and the risk assessment of the sector. Despite these considerations, studies that focus directly on the development of hybrid methodologies for the evaluation and improvement of performance in occupational safety and health in the electrical sector, under multiple criteria and uncertainty are mostly limited. Therefore, this document presents an integrated methodology for improving the performance in occupational health and safety in the electric sector through the application of two techniques of Multi-criteria Decision Methods (MCDM) uses in environments under uncertainly. First, the fuzzy Analytic Hierarchy Process (FAHP) is applied to estimate the initial relative weights of criteria and sub-criteria. The fuzzy set theory is incorporated to represent the uncertainty of decision-makersâ preferences. Then, the Decision-making Trial and Evaluation Laboratory (DEMATEL) used for evaluating the interrelations and feedback among criteria and sub-criteria. FAHP and DEMATEL are later combined for calculating the final criteria and sub-criteria weights under vagueness and interdependence. Subsequently, we applied the proposed methodology in a company of the energy sector for diagnosis of performance in OHS to establish improvement proposals, the work path, and implementation costs. Finally, we evaluate the impact of the strategies applied in the improvement of the performance of the company
Desenvolvimento e validação de modelo de previsão para mancha preta dos citros em função de variåveis meteorológicas
InfluĂȘncia da temperatura e da luminosidade no desenvolvimento de Guignardia citricarpa, agente causal da mancha preta dos frutos cĂtricos
From "Infant Hercules" to "Ghost Town":Industrial collapse and social harm on Teesside
This article explicates the harms associated with deindustrialization in Teesside in the North East of England in the context of neoliberalism. Drawing on in-depth qualitative interviews (nâ=â25), the article explores how ongoing industrial collapse, typified by Sahaviriya Steel Industriesâ (SSI) closure in 2015, has generated various harms. First, the article examines industrialismâs socioeconomic security and stability. It then explores the negative impact of SSIâs closure in 2015, including a sense of loss and unemployment. Next, it demonstrates how the absence of economic stability produces harmful outcomes, namely insecurity, mental health problems and bleak visions of the future. The article concludes by casting industrial ruination as an impediment to human flourishing; the normal functioning of capitalism represents a ânegative motivation to harmâ that prevents the stability and security necessary for individual and collective flourishin
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