34,482 research outputs found

    The development of the Kent coalfield 1896-1946

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    One of the unique features of the Kent Coalfield is that it is entirely concealed by newer rocks. The existence of a coalfield under southern England, being a direct link between those of South Wales, Somerset and Bristol in the west and the Ruhr, Belgium. and northern France in the east, was predicted by the geologist R. A. C. Godwin-Austen as early as 1856. It was, however, only the rapid increase in demand for Britain's coal in the last quarter of the nineteenth century that made it worth considering testing this hypothesis. The first boring was made in the years 1886-90, and although it discovered coal, this did not in itself prove the existence of a viable coalfield. This could be done only by incurring the heavy cost of boring systematically over a wide area. As the financial returns from such an undertaking were uncertain, it was not surprising that in the early years, around the turn of the century, a dominant role was played by speculators, who were able to induce numerous small investors to risk some of their savings in the expectation of high profits. As minerals in Britain were privately owned, the early pioneer companies not only had to meet the cost of the exploratory borines, but also, if they were not to see the benefit of their work accrue to others, lease beforehand the right to mine coal from local landowners in as much of the surrounding area as possible. This policy was pursued most vigorously by Arthur Burr, a Surrey land specula tor, who raised capital by creating the Kent Coal Conoessions Ltd. and then floating a series of companies allied to it. Burr's enterprise would probably have been. successful had it not been for the water problems encountered at depth in -v- the coalfield. As a result, the Concessions group found itself in control of most of the coalfield, but without the necessary capital to sink and adequately equip its 01ffi collieries. By 1910, however, the discovery of iron ore deposits in east Kent, coupled with the fact that Kent coal was excellent for coking purposes, began to attract the large steel firms of Bolckow, Vaughan Ltd. and Dorman, Long & Co. Ltd. in to the area. The First World War intervened, however, to delay their plans, and to provide an extended lease of life to the Concessions group, which, by the summer of 1914, was facing financial collapse. By the time Dorman, Lone & Co, in alliance with Weetman Pearson (Lord Cowdray), had acquired control over the greater part of the coalfield from the Concessions group, not only was the country's coal industry declining, but so was its steel industry, which suffered an even more severe rate of contraction during the inter-war years. As a result, Pearson and Dorman Long Ltd. was forced to concentrate just on coal production, and this in turn was hampered not only by the water problems, but also by labour shortages and the schemes introduced by the government in 1930 to restrict the country's coal output, in an attempt to maintain prices and revenue in the industry. Nevertheless, production did show a substantial increase between 1927 and 1935, after which it declined as miners left the coalfield to return to their former districts, where employment opportunities were improving in the late thirties. Supporting roles were played in the inter-war years by Richard Tilden Smith, a share underwriter turned industrialist with long standing interests in the coalfield, who acquired one of the Concessions group's two collieries, and by the Powell Duffryn Steam Coal Co. Ltd., which through subsidiary companies, took over the only colliery to be developed by a pioneer company outside the Concessions group. The impossibility of Kent coal, because of its nature, ever gaining more than token access to the more lucrative household market, and then the failure of the local steel industry to materialise meant that the -vi- companies had to develop alternative outlets for their growing outputs. Although nearness to industrial markets in the south-east of England did confer certain advantages were poor consolation for the hoped for developments of either the early pioneers or the later industrialists. Instead of the expected profits, the companies mostly incurred losses, and only the company acquired by Powell Duffryn ever paid a dividend to its shareholders in the years before nationalisation. From the point of view of the Kent miners, the shortage of labour in the coalfield, particularly in the years 1914-20 and 1927-35, was to an important extent responsible for their being amongst the highest paid in the industry. At the same time the more favourable employment opportunities prevailing in Kent compared with other mining districts enabled the Kent Nine Workers Association to develop into a well organised union, which on the whole was able to look after the interests of its members fairly successfully. Throughout the period 1896 to 1946 the Kent Coalfield existed very much at the margin of the British coal industry. Its failure to develop substantially along the lines envisaged by either the early pioneers or by the later industrialists meant that its importance in national terms always remained small

    Comparison between a Polyaspartate based additive and conventional techniques for tartaric stabilisation

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    Mestrado Vinifera Euromaster - Viticulture and Enology - Instituto Superior de AgronomiaAmong the various enological products authorized by the European legislation, metatartaric acid (MTA) and carboxymethyl cellulose (CMC) are the most widely used to prevent tartrate salts instability, although showing some drawbacks concerning long-term efficacy the former, and colour instability the latter. Recently, an additive based on potassium polyaspartate (KPA) has been evaluated with regards to tartaric stabilisation, to obtain the admission of its use by the European Commission in 2017. The following thesis project developed at the Research Centre of Laimburg (Italy) aims to test the stabilisation effectiveness of potassium polyaspartates (KPA) on local red and white wines, in comparison with the two most widely used additive agents (MTA and CMC) and a subtractive technique (cold stabilisation). Analysis of stability were carried out over a period of six months, as well as chemical-physical parameters (turbidity, tartaric acid, chromatic characteristics) and sensory evaluations of each treatment. Statistical analysis between all trials’ results confirmed the importance of time in recognising the different performances of the used additives aimed to inhibit the crystallisation process of tartaric acid salts, whose behaviour produced different responses with regard to tartrate stability, turbidity and sensory profile. Best results were observed in wines treated with potassium polyaspartate (KPA) and cold stabilisation, although the latter is considered to bring some drawbacks related to operating costs, thus sustainability. Storage temperature effect (35°C) on the different treatments was also evaluated, obtaining again good responses from the polyaspartate based product, although depending on the dose applied. Sensory evaluation confirmed that the debate is still current, expressing greater preference towards cold stabilisation rather than any additive treatmentN/

    Carbon dioxide removal potential from decentralised bioenergy with carbon capture and storage (BECCS) and the relevance of operational choices

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    Bioenergy with carbon capture and storage (BECCS) technology is expected to support net-zero targets by supplying low carbon energy while providing carbon dioxide removal (CDR). BECCS is estimated to deliver 20 to 70 MtCO2 annual negative emissions by 2050 in the UK, despite there are currently no BECCS operating facility. This research is modelling and demonstrating the flexibility, scalability and attainable immediate application of BECCS. The CDR potential for two out of three BECCS pathways considered by the Intergovernmental Panel on Climate Change (IPCC) scenarios were quantified (i) modular-scale CHP process with post-combustion CCS utilising wheat straw and (ii) hydrogen production in a small-scale gasifier with pre-combustion CCS utilising locally sourced waste wood. Process modelling and lifecycle assessment were used, including a whole supply chain analysis. The investigated BECCS pathways could annually remove between −0.8 and −1.4 tCO2e tbiomass−1 depending on operational decisions. Using all the available wheat straw and waste wood in the UK, a joint CDR capacity for both systems could reach about 23% of the UK's CDR minimum target set for BECCS. Policy frameworks prioritising carbon efficiencies can shape those operational decisions and strongly impact on the overall energy and CDR performance of a BECCS system, but not necessarily maximising the trade-offs between biomass use, energy performance and CDR. A combination of different BECCS pathways will be necessary to reach net-zero targets. Decentralised BECCS deployment could support flexible approaches allowing to maximise positive system trade-offs, enable regional biomass utilisation and provide local energy supply to remote areas

    Non-Print Information Resources and The Preservation Approaches Recommendation in Tanzanian Academic Libraries

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     Background: Non-print information resources are increasingly becoming more important as vital learning materials in higher learning institutions. Academic libraries therefore, have to acquire, process, organize and preserve them for current and future use. Purpose: This paper aims to assess the factors affecting the non-print information resources and their recommended preservation approaches in academic libraries.  Method: The study adopted a convergent parallel mixed approach which collects and analyses data to produce integrated findings by using both qualitative and quantitative techniques in a single study. Data was collected by means of questionnaire and in-depth interview. Result: The study revealed that dust, loss of data on disc and hard disc, loss of data due to server failure, high heat, and excessive light, fading of disc surface, high humidity, fungus on disc surface, atmospheric pollutants and virus attack were factors affecting non-print information resources. It was also revealed that highly recommended preservation approaches were good cleanliness of library where information resources are kept, educating library users on how to handle and use information resources, migrating information resources from obsolete storage media to modern storage media, technology preservation and refreshing. Conclusion: The study concludes that library staff need to adopt recommended preservation approaches to safeguard the important information in academic libraries but also system librarians in academic libraries need to be employed to assist in trouble shooting issues.  Keywords: Non-Print Information Resources; Information Resources; Information Resources Preservation; Preservation Approaches; Academic Library   Abstrak  Latar Belakang: Sumber informasi non-cetak sekarang ini menjadi semakin penting sebagai bahan pembelajaran vital di perguruan tinggi. Oleh karena itu, perpustakaan akademik harus memperoleh, memproses, mengatur, dan melestarikannya untuk penggunaan saat ini dan masa depan. Tujuan: Makalah ini bertujuan untuk menilai faktor-faktor yang mempengaruhi sumber informasi non-cetak dan pendekatan pelestarian yang direkomendasikan di perpustakaan akademik. Metode: Studi ini mengadopsi pendekatan campuran paralel konvergen yang mengumpulkan dan menganalisis data untuk menghasilkan temuan yang terintegrasi dengan menggunakan teknik kualitatif dan kuantitatif dalam satu studi. Pengumpulan data dilakukan dengan kuesioner dan wawancara mendalam. Temuan: Hasil penelitian menunjukkan bahwa debu, hilangnya data pada disk/hard disk, hilangnya data karena kegagalan server, panas yang tinggi, dan cahaya yang berlebihan, memudarnya permukaan disk, kelembaban tinggi, jamur pada permukaan disk, polutan atmosfer dan serangan virus adalah faktor yang mempengaruhi sumber informasi non-cetak. Diungkapkan juga bahwa pendekatan pelestarian yang sangat direkomendasikan adalah kebersihan perpustakaan tempat sumber informasi disimpan, mendidik pengguna perpustakaan tentang cara menangani dan menggunakan sumber informasi, migrasi sumber informasi dari media penyimpanan usang ke media penyimpanan modern, pelestarian teknologi dan penyegaran koleksi. Kesimpulan: Studi ini menyimpulkan bahwa staf perpustakaan perlu mengadopsi pendekatan pelestarian yang direkomendasikan untuk melindungi informasi penting di perpustakaan akademik, tetapi juga pustakawan di perpustakaan akademik perlu dioptimalkan untuk membantu memecahkan masalah yang ada.  Kata kunci: Sumber Informasi Non-Cetak; Sumber Daya Informasi; Pelestarian Sumber Daya Informasi; Pendekatan Pelestarian; Perpustakaan Akademik&nbsp

    Probing the Intergalactic medium properties using X-ray absorption from multiple tracers

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    Based on the Lambda Cold Dark Matter concordance cosmological model (ΛCDM), the majority of baryons exist in the Intergalactic medium (IGM). It is extremely challenging to observationally trace the IGM, especially at higher temperatures and low densities. Post reionisation, the vast majority of hydrogen and helium is ionized in the IGM and therefore, the observation of metals is essential for parametrising the IGM properties. My hypothesis is that there is significant absorption in the diffuse highly ionisied IGM and that this IGM column density increases with redshift. I use X-ray absorption in multiple tracers which yields information on the total absorbing column density of the matter between the observer and the source. Clear IGM detections require tracer sources that are bright, distant, and common enough to provide a good statistical sample of IGM lines of sight (LOS). To more accurately isolate any IGM contribution to spectral absorption, I examine each tracer host type to realistically model it, in addition to using appropriate intrinsic continuum curvature models. I test the robustness of the result from a number of perspectives. I examine the impact of the key underlying assumptions that affect the column density calculations including metallicity, ionisation and location of absorption. I look for any evidence of evolution in the parameters. In Chapters 2, 3, 4 and 5, I use gamma-ray bursts (GRBs), blazars and quasars (QSOs) to estimate IGM baryon column densities, metallicity, temperature, ionisation parameters and redshift distributions. My results for each tracer are presented in each of the respective chapters and collectively in Chapter 5 which includes comparative analysis. In conclusion, through the work in this thesis I demonstrate a consistent case for strong X-ray absorption in the IGM on the LOS to three different tracer types and that it is related to redshift. The results are consistent with the ΛCDM model for density, temperature and metallicity. Given these results, I would recommend that studies of distant objects should not follow the convention of assuming all X-ray absorption in excess of our Galaxy is attributed to the host galaxy, that the host is neutral and has solar metallicity. Instead, particularly at higher redshift, absorption in the IGM should be accounted for to give more accurate results for the tracer host properties

    Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole

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    Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates

    Bioinformatic characterization of a triacylglycerol lipase produced by Aspergillus flavus isolated from the decaying seed of Cucumeropsis mannii

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    Lipases are enzymes of industrial importance responsible for the hydrolysis of ester bonds of triglycerides. A lipolytic fungus was isolated and subsequently identified based on the ITS sequence analysis as putative Aspergillus flavus with accession number LC424503. The gene coding for extracellular triacylglycerol lipase was isolated from Aspergillus flavus species, sequenced, and characterised using bioinformatics tools. An open reading frame of 420 amino acid sequence was obtained and designated as Aspergillus flavus lipase (AFL) sequence. Alignment of the amino acid sequence with other lipases revealed the presence GHSLG sequence which is the lipase consensus sequence Gly-X1-Ser-X2-Gly indicating that it a classical lipase. A catalytic active site lid domain composed of TYITDTIIDLS amino acids sequence was also revealed. This lid protects the active site, control the catalytic activity and substrate selectivity in lipases. The 3-Dimensional structural model shared 34.08% sequence identity with a lipase from Yarrowia lipolytica covering 272 amino acid residues of the template model. A search of the lipase engineering database using AFL sequence revealed that it belongs to the class GX-lipase, superfamily abH23 and homologous family abH23.02, molecular weight and isoelectric point values of 46.95 KDa and 5.7, respectively. N-glycosylation sites were predicted at residues 164, 236 and 333, with potentials of 0.7250, 0.7037 and 0.7048, respectively. O-glycosylation sites were predicted at residues 355, 358, 360 and 366. A signal sequence of 37 amino acids was revealed at the N-terminal of the polypeptide. This is a short peptide sequence that marks a protein for transport across the cell membrane and indicates that AFL is an extracellular lipase. The findings on the structural and molecular properties of Aspergillus flavus lipase in this work will be crucial in future studies aiming at engineering the enzyme for biotechnology applications
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