The world energy demand has become higher with the growing population, which has translated into an increase in emission of greenhouse gases into the atmosphere. For this reason, CO2 capture and storage has been undertaken to purify the atmosphere. For storing this CO2, it is necessary to have wells to inject it (deeper than 800 m); moreover, these wells need to have stability over time, and one of the stability aspects is the protection of steel against corrosion. Considering this aspect, the most common steels (focussed on American Petroleum Institute [API] steels) that can be used in an injector well were studied. The best performance was obtained using a high alloy content of Cr and Ni. Furthermore, the most important parameter analysed when corrosion is studied is the test time, which was modelled to stabilise the corrosion rates. The experiments were undertaken after a general review of different studies that investigated the corrosion of steel when in contact with CO2 in the vapour phase and under supercritical conditions.
Heavy mineral component of 13 samples from the Lokoja and Patti Formations, Bida Basin have been studied for their textural characteristics, compositional abundance, maturity and provenance determinations. The suite of heavy minerals encountered is classified as opaque and non-opaque constituents. The non-opaque components include zircon, tourmaline, rutile, garnet, staurolite, epidote, kyanite, titanite, lawsonite, cassiterite, sillimanite, hornblende, hypersthene and andalu-site. The assemblage is generally dominated by zircon and tourmaline in the two formations. The constituent heavy minerals identified are dominated by ultra-stable and stable classes, whereas the ZTR indices indicate mineralogical immaturity coupled with textural immaturity of the constituent grains. This suggests the possible dominance of chemical weathering of the source rock. The suites of minerals recovered have been linked to both metamorphic and non-metamorphic crystalline rock origins.
The paper describes the problem of conversion of heights to the European Vertical Reference Frame 2007 for Poland (PL-EVRF2007-NH). The subject of the study is height data, and especially the detailed vertical reference network. The aim of the article is to present an alternative method of conversion to the one recommended by the Polish Head Office of Geodesy and Cartography. The proposed approach is characterised by a low implementation cost while maintaining the required accuracy.
The publication is illustrated by the case of Kętrzyn district (in the north-east part of Poland). The local reference network was converted from Kronstad’60 to PL-EVRF2007-NH in 2017.
Accessing finances for housing has been a major problem for people on low-incomes and this has been weighing heavily on them as they try to access housing. Financial institutions in the city of Bulawayo are failing to come up with financial products that suit low-income clients. There are an estimated 110000 low-income residents among the estimated 250000 residents of Cowdray Park low-density residential area in Bulawayo. This has also affected their right to the city as they have been excluded from the housing delivery system. There are so many initiatives that have been available to those on a low-income but these initiatives have rarely benefited the urban poor of the city. This research has examined how the financial services that exist in the housing sector have been crafted to benefit the urban poor. The research employed a mixed methods approach to the inquiry, where a questionnaire was the main quantitative method used and in-depth interviews and observations were the qualitative methods that complemented it. The research found that there are various financial services that are available in Zimbabwe, but these financial facilities rarely help the urban poor. The majority of the poor have been managing without any financial support and this has been stalling their access to housing. Most housing products are fashioned along neo-liberal economic principles that have very little to offer the urban poor. This has therefore denied the urban poor in the city of Bulawayo their right to the city. Most cities in Zimbabwe are struggling to satisfy their housing demand as they have long housing waiting lists. Research therefore recommends the crafting of financial facilities that are best targeted on the urban poor, and are specially adapted to their financial conditions.
Slum redevelopment is occurring at a rapid pace in many African cities. This paper examines the urban development of contemporary Luanda, the capital of Angola. Central to this examination is an analysis of the city’s slums according to Foucault’s concept of governmentality. The focus is on the chaotic urban development that has resulted from the civil war and on the effects of poverty and gentrification in many of Luanda’s slums. The policy of violence towards slum population adopted by the municipality appears to define a technology of domination, the subjection of the individual to the formation of the state. However, with the high earnings obtained from oil production, the country clearly has the resources needed to fund investments in electricity and utility systems. The continuing persistence of slums and a housing policy based on neglect signifies a form of governmentality, adopted as a means of government coercion and a way of dominating the poor population. The paper closes with a set of policy implications for action.
The economic and social drivers of democratisation and the emergence and establishment of democratic institutions are longstanding themes of academic discourse. Within this broad body of literature, it has been argued that the process of urbanisation is also conducive to the emergence and consolidation of democracy through a number of different channels. Cities offer better access to education and facilitate organised public action and the demand for more democratic rule and respect of human rights. The nexus between urbanisation and human rights is the theme that is taken up in the present paper. Using a sample of 123 countries for the period 1981–2011, the paper examines empirically the association between urbanisation and human empowerment using the Cingranelli-Richards Index. In broad terms, the findings reported herein do not point to a strong nexus across all income groups. Nevertheless, there is evidence suggesting the presence of such a statistically significant positive association in specific cases.
A policy instrument promoting a free fare public transport policy (FFPT) has recently been put into practice in 66 municipalities across Poland. By contributing to the academic debate on the concept of FFPT (e.g. Kębłowski 2019), the main goal of this paper is to create a typology of the schemes where FFPT is in operation in Poland based on analyses of a geographical mapping of these projects. This study analyses how different municipalities are implementing the concept in order to define a typology of FFTP projects and to understand how the development landscape of the urban transport system is changing in the light of free fare transport policies, topics which are not fully covered in the academic literature. The findings confirm that there is a new dynamic in the development of urban transport systems and permit the identification of key characteristics of this trend. Besides the typology of implementation of FFPT, the study also presents an up-to-date inventory of FFPT projects with the key characteristic features of each system. Although the study does not provide specific recommendations regarding the introduction of a FFPT policy, it represents a good starting point for future and more detailed studies. Such studies are necessary in order to understand the role of FFPT not only in the context of the development of a given transport system, its impact on modal split, and travel behaviour, but also to uncover the different politics which lie behind them.
During the 1990s the Celtic Tiger era began in the Republic of Ireland. This article tracks the response of the Irish Urban System to that remarkable period of growth ended abruptly with the Global Economic Crisis of 2008. Using Small Area Population Statistics from Ireland’s Central Statistics Office for the years 1996, 2002, 2006 and 2011 it was possible to record growth across the towns and cities of Ireland that constituted the Irish Urban System. The location, size, type and rates of change were recorded and mapped with a view towards discovering the extent to which the urban hierarchy and the spatial distribution was being altered, and by what geographical processes. Over 15 years the national population grew by 26% with most of that growth taking place in urban centres. A clear diffusion outwards from the Dublin region is noticeable and the capital’s role in systemic change is explored alongside other factors. The article highlights the changing nature of growth over time and, based on the empirical observations made, identifies a sequence of clear stages in the growth of the urban system. The article concludes with a proposal for a Model of Urban System Evolution under conditions of Rapid Economic Growth based on the distinct phases, or stages, of growth identified in Ireland’s towns and cities from 1996–2011.
The article discusses a method applied for combining the results of Global Navigation Satellite Systems (GNSS) and 75-year old triangulation measurements to estimate the crustal movements in central western Bulgaria region. It was examined for joint analysis based on the results of GNSS with angular measurements of the first order triangulation network in Bulgaria during the period 1923–1930 year. As a result of the processing of GNSS and angular measurements, horizontal velocities of 15 points, strain rates, and rotation rates have been obtained. The results show dominating N–S extension at a rate of 1–2 mm/y and the deformation is not uniformly distributed over the studied area. The obtained results indicate the possibility of using old angular measurement of first-order triangulation points, together with GNSS data, to obtain estimates of the horizontal crustal movements.
The present study deals with the estimation of the evolution tendency of the environmental stage of a protected habitat with predominant forest vegetation, during a short period of time, using techniques specific to remote sensing. Therefore, two important spectral indexes were tested while assessing the health of the forest ecosystems: i.e. the Normalized Difference Vegetation Index (NDVI) and the Structure Insensitive Pigment Index (SIPI). The period of time taken into consideration for the study was, 2013 - 2019, having used medium resolution satellite photos, Landsat 8 OLI, having initially undergone standard pre-processing operations (resize data, radiometric calibration, atmospheric correction). The satellite images modified according to the Top of Atmosphere Reflectance and corrected topographically resulted into getting values for the two before mentioned indexes. The quantity-spatial results obtained, correlated to the monthly values of the precipitations processed in order to obtain the SPI (Standardized Precipitation Index), mostly reveal, in what SIPI and also NDVI are concerned, a slight decrease in the quality of the forest on the analysed area in the sense that the vegetation stress is increased under meteorological factors, expressed differently depending on the morphometric and pedological parameters of the habitat.