477 research outputs found

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    This final design report will detail the entire engineering design process from conceptualization through manufacturing and testing. After introducing the topic and scope of the project this document presents all of the benchmarking and research performed in order to obtain as much information about similar current products and possible solutions. Next the objectives of the project are presented where the needs are transformed into engineering specifications that will guide the design of the product. Design developed is then presented with ideation, idea evaluation and selection, analysis, manufacturing considerations, and final design selection. The final design is then presented with each of its three subsystems, including supporting analysis, manufacturing and testing plans, bill of materials and cost as well as material selection, safety considerations, and maintenance plans. Following that is the management plan where team roles are outlines and project deadlines are presented. Product realization is next, which includes the manufacturing process that was taken for all components as well as description of changes between the planned and built design and recommendations for future manufacturing changes. Design verification follows with testing procedures and results and a final budget for the manufactured design. Next are conclusions that summarize what was done during the project and recommendations which outline what could have been done differently from a design or project standpoint to provide insight for future designs. References for all researched information are included in order cited throughout the document. Finally all appendices are included at the end of the document that were referenced throughout the report as well as other important information

    Protective Coatings for the Graphite Facing in Calcium-Aluminothermal Processes

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    Results of pilot plant and full scale studies on the elaboration of high temperature protective coatings for graphite in the process of the reductive melting of niobium pentoxide and NbAl alloys production are presented. Graphite has found extensive application in high temperature processes due to its unique thermophysical properties. However, in these conditions it reacts very easily with air oxygen, liquid metals, oxides, and fluorides. As a result, porous graphite gets impregnated with liquid metal; besides, carbonization of melt and formation of a layer of metal carbides on graphite surface takes place. The layer of metal carbides has a low adhesion with graphite and a major part of them is transferred to the melt. The graphite facing of a furnace is quickly destructed. To avoid these harmful processes, special plasma sprayed protective coatings are used. In this work various coatings (Al2O3, Al2O3-CaO, ZrO2, NbC, Al2O3 + Nb, ZrO2 + Nb, NbC + Nb, Nb) were tested in pilot plant and industrial conditions. It was established that the best durability of the protective coating on graphite can be achieved in the case of its three-layer composition: Nb (0.07 mm) + NbC (0.4 mm) + Nb (0.3 mm). After industrial melting of 500-2000 kg ingots about 80% of this coating on the belt of the shaft furnace had preserved. Plasma sprayed protective coatings on the graphite facing extended its operation time, reduced the carbon content in the metal ingots to 0.02% (mass), and slag carbon content to 0.05-0.15% (mass).The financial support to V. G. from the Doctorate School of the Faculty of Chemical and Materials Technology of Tallinn University of Technology is gratefully acknowledged

    Reduction of Tantalum Pentoxide with Aluminium and Calcium: Thermodynamic Modelling and Scale Skilled Tests

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    High reactivity of powdered aluminium together with its relatively low price are the main reasons for the application of this metal as a reducing agent for the reduction of oxides and fluorides of rare and rare earth metals by the aluminothermal method. This technology is widely used in the production of master alloys for ferrous metallurgy. The "out-of-furnace" process (i.e. without external heat access) is the prevailing technology for metallic niobium production worldwide. However, aluminothermal reduction for industrial production of metallic tantalum has been limited because of the high required temperature, over 2800 °C. In this paper the results of simultaneous reduction of tantalum(V) and iron(III) oxides by calcium-aluminothermal "out-of-furnace" process are presented. Powdered aluminium and metallic calcium were used as reductants. The pickup of tantalum at smeltings with the mass of raw materials over 1 kg reached 94%. The metal was obtained in the form of compact ingot; separation of metallic and slag phases was excellent. Crushed melt underwent refining remelting in an electron beam furnace. For thermodynamic studies and optimization of the aluminothermal reduction processes of Ta2O5 and Fe2O3 in the temperature range of 1000-3000°C a licensed computer simulation program "HSC Chemistry 6.1, 2007", elaborated by the company Outotec Oy, was applied

    Effects of White Space in Learning via the Web

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    This study measured the effect of specific white space features on learning from instructional Web materials. The study also measured learners' beliefs regarding Web-based instruction. Prior research indicated that small changes in the handling of presentation elements can affect learning. Achievement results from this study indicated that in on-line materials, when content and overall structure are sound, minor differences regarding table borders and vertical spacing in text do not hinder learning. Beliefs regarding Web-based instruction and instructors who use it did not differ significantly between treatment groups. Implications of the study and cautions regarding generalizing from the results are discussed.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    The Ki-67 and Repoman mitotic phosphatases assemble via an identical, yet novel mechanism

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    Ki-67 and RepoMan have key roles during mitotic exit. Previously (Booth et al, eLife, 2014), we showed that Ki-67 organizes the mitotic chromosome periphery and recruits protein phosphatase 1 (PP1) to chromatin at anaphase onset, in a similar manner as RepoMan. Here we show how Ki-67 and RepoMan form mitotic exit phosphatases by recruiting PP1, how they distinguish between distinct PP1 isoforms and how the assembly of these two holoenzymes are dynamically regulated by Aurora B kinase during mitosis. Unexpectedly, our data also reveal that Ki-67 and RepoMan bind PP1 using an identical, yet entirely novel mechanism, interacting with a PP1 pocket that is engaged only by these two PP1 regulators. These findings not only show how two distinct mitotic exit phosphatases are recruited to their substrates, but also provides immediate opportunities for the design of novel cancer therapeutics that selectively target the Ki-67:PP1 and RepoMan:PP1 holoenzymes

    Johnston Press and the Crisis in Ireland's Local Newspaper Industry, 2005-2014

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    Reflecting international trends, Ireland’s local newspaper industry has suffered steep circulation and advertising revenue falls since the late-2000s, and has struggled to reshape traditional business models for the digital era. In harsh trading conditions, local titles are operating on reduced editorial resources and are weakened in their capacity to fulfil their traditional watchdog and informed-citizenry functions. Perhaps no company better encapsulates the industry’s recent difficulties than UK media group Johnston Press. In 2005, it paid more than €200m to acquire fourteen local titles in Ireland, but nine years later sold them for just €8.5m. The article draws on this case-study to consider wider issues related to the corporatisation of local news provision, the sustainability of local news industries in small media markets such as Ireland’s, and the increasing disconnect between local journalism’s commodity value and its public good value

    Intensity modulated radiotherapy (IMRT) in patients with carcinomas of the paranasal sinuses: clinical benefit for complex shaped target volumes

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    INTRODUCTION: The aim of the study was to evaluate the clinical outcome of intensity modulated radiotherapy (IMRT) in 46 patients with paranasal sinus tumors with special respect to treatment-related toxicity. PATIENTS AND METHODS: We treated 46 patients with histologically proven tumors of the paranasal sinuses with IMRT. Histological classification included squamous cell carcinoma in 6, adenocarcinoma in 8, adenoidcystic carcinoma in 20 and melanoma in 8 patients, respectively. Six patients had been treated with RT during initial therapy after primary diagnosis, and IMRT was performed for the treatment of tumor progression as re-irradiation. RESULTS: Overall survival rates were 96% at 1 year, 90% at 3 years. Calculated from the initiation of IMRT as primary radiotherapy, survival rates at 1 and 3 years were 95% and 80%. In six patients IMRT was performed as re-irradiation, and survival rate calculated from re-irradiation was 63% at 1 year. Local control rates were 85% at 1, 81% at 2 and 49% at 3 years after primary RT and 50% at 1 year after re-irradiation. Distant metastases-free survival in patients treated with IMRT as primary RT was 83% after 1 and 64% after 3 years. For patients treated as primary irradiation with IMRT, the distant control rate was 83% at 1 year and 0% at 2 years. No severe radiation-induced side-effects could be observed. CONCLUSION: IMRT for tumors of the paranasal sinuses is associated with very good tumor control rates. Treatment-related acute and long-term toxicity can be minimized as compared to historical results with conventional RT
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