Results 1 - 7 of 7
Results 1 - 7 of 7. Search took: 0.015 seconds
|Sort by: date | relevance|
[en] A fluid flow analysis and particle trajectory in a 5 t molten capacity scaled 1.2 model of a reverberatory furnace was performed using both physical and numerical simulation. The design of the system allowed studying the behavior of the liquid in a system agitated by impellers. The parameters studied were, rotating shape and height, of the impeller. The physical and numerical simulations were used to determine circulation and mixing times, fluid flow patters and velocity profiles in the agitation and melting chambers. Using experimental data, it was possible to establish the interaction between turbulent flow and circulating solid particles. The original design of the reverberatory furnace was modified based on the physical and numerical simulation analysis. The new design showed an increased magnesium removal rate by means of a more efficient and faster mixing. (Author) 18 refs.
[en] Predicting the temperature of the steel strip in the annealing process in a hot-dip galvanizing line (HDGL) is important to ensure the physical properties of the processed material. The development of an accurate model that is capable of predicting the temperature the strip will reach according to the furnaces variations in temperature and speed, its dimensions and the steels chemical properties, is a requirement that is being increasingly called for by industrial plants of this nature. This paper presents a comparative study made between several types of algorithms of Data Mining and Artificial Intelligence for the design of an efficient and overall prediction model that will allow determining the strips variation in temperature according to the physico-chemical specifications of the coils to be processed, and fluctuations in temperature and speed that are recorded within the annealing process. The ultimate goal is to find a model that is effectively applicable to coils of new types of steel or sizes that are being processed for the first time. This model renders it possible to fine-tune the control model in order to standardise the treatment in areas of the strip in which there is a transition between coils of different sizes or types of steel. (Author).
[en] The setting up of the Committee of Works of the Port of Huelva coincided with the revitalization of mining in the province during the last third of the 19th century, stimulated by the injection of the foreign capital and technology. The mining legislation concerning customs duties of 1868 also contributed to triggering mining fever. For its part, the Port of Huelva began its administrative development within a succession of norms by which other similar bodies were progressively created along the Spanish coasts, with the encouragement of the local middle-classes. Mineral ores began to emerge from the bowels of the earth in Huelva at the eager hands of the miners, especially copper, manganese and pyrites, which was transported by the railways to the Port of Huelva, from whence, thanks to the development of its infrastructure, they were subsequently exported, mainly to a Europe in the throes of its second industrial revolution. (Author) 49 refs.
[en] The objective was to develop a comprehensive strategy that answers to the need of today European PV industry. Namely: - Develop PV markets in Europe - Develop export markets. - Position the European PV industry within the European political environment and support the effort of national actors in their local objectives. This method lends itself to brainstorming to create actions and synergies, on order to achieve strategy objectives. The whole work is based on working groups clearly defined on the purpose, where all EPIA members are invited to participate. The overall first results are presented during the 19. EU PV Conference in Paris and EPIA will do recommendations on actions to be undertaken in the future. This strategy is co-financed by EPIA members and the 6. Framework Programme for research of the European Commission through the PV Catapult project. (authors)
[en] An old question of solid state physics is being answered nowadays: the atomic-level understanding of ferro electricity. Traditional ideas about ferroelectric phenomena relate with softening of optical phonons at the Brillouin zone origin and with 'W-shaped' Landau free energy functions. Last decade experimental (synchrotron radiation, neutrons) and quantum-theoretical (Cohen, Resta, Spaldin) contributions have clarified detailed descriptions and explanations for atomic behavior leading to spontaneous polarization in perovskite and perovskite-related crystal structures. Work being performed by our interdisciplinary group on ferro electricity is presented. Perovskite and Aurivillius ferroelectric phases are obtained by different methods. Fine details on crystal structures are investigated by means of synchrotron radiation at Stanford Synchrotron Radiation Laboratory. Electronic structures of considered phases are theoretically characterized by ab initio methods. High-resolution diffraction experiments demonstrate several symmetry break-downs in perovskite and Aurivillius phases. The structure- symmetry-polarization relationship is discussed for a number of representative cases. Ab initio explanation of ferroelectric polarization in perovskite structures is given. Energy calculation is performed by means of CASTEP code under GGA functional. Energy optimization leads to cubic-tetragonal symmetry break-down with off-centering cation displacements via second-order Jahn-Teller effect. Electronic structure is investigated with Band Lab code, under LDA functional with LMTO method. Degeneracy of Ti 3d z2 and Ti 3d (x2 + y2) orbitals is the cause of cubic-perovskite deformation. (Author)
[en] Recommended treatment for most patients with differentiated thyroid cancer is surgery followed by radioiodine ablation. Current practice in many centres is to use a high administered activity of 3.7 GBq (100 mCi). However, a lower activity (1.1 GBq or 30 mCi) has advantages including a shorter stay in hospital isolation and lower risk of side effects, including the risk of a second cancer. Also, Thyrogen (rhTSH) allows patients to continue thyroid hormone replacement during ablation, avoiding symptoms of hypothyroidism and also reduces total body radiation dose. We conducted a large randomized factorial multi centre trial to simultaneously address whether ablation success rates are similar using (i) either 1.1 GBq or 3.7 GBq, and (ii) either Thyrogen or thyroid hormone withdrawal. It is the first ever national prospective trial in thyroid cancer in the UK. Final results will be available in 2011
[en] Signal transducer and activator of transcription 3 (Stat) is a cytoplasmic protein that is activated in response to cytokines and growth factors and acts as a transcription factor. Stat plays critical roles in various biological activities including cell proliferation, migration, and survival. Studies using keratinocyte-specific Stat-deficient mice have revealed that Stat plays an important role in skin homeostasis including keratinocyte migration, wound healing, and hair follicle growth. Use of both constitutive and inducible keratinocyte-specific Stat-deficient mouse models has demonstrated that Stat is required for both the initiation and promotion stages of multistage skin carcinogenesis. Further studies using a transgenic mouse model with a gain of function mutant of Stat (Stat3C) expressed in the basal layer of the epidermis revealed a novel role for Stat in skin tumor progression. Studies using similar Stat-deficient and gain-of-function mouse models have indicated its similar roles in ultraviolet B (UVB) radiation-mediated skin carcinogenesis. This paper summarizes the use of these various mouse models for studying the role and underlying mechanisms for the function of Stat in skin carcinogenesis. Given its significant role throughout the skin carcinogenesis process, Stat is an attractive target for skin cancer prevention and treatment.