886 resultados para Two Stage Process


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The aim of this study was to examine suitability of BimTwin cleaning concept in card board machine to control microbiological activity and describe microbiological balance of the machine. In a review of literature is examined microbe and spore caused problems in paper industry. Biggest problems are deposits, which decrease runnability and cause quality errors. In this chapter is also introduced most common oxidizing biocides used in paper industry and described ATP assay as a microbiological monitoring method. In an experimental part are included BimTwin mill trial results, chemical condition monitoring methods and microbiological balance in a card board machine. In a second part are examined possibilities to effect hygiene of card board by chemical treatment of the surface size and coating. Result showed that BimTwin concept is suitable for card board machine as a cleaning concept, when chemical dosing is fitted right. For proper dosing and secure tolerable hygiene level, chemical and microbiological monitoring is significant. Determining of the microbiological balance would have need more sampling. According to acquired results, broke turned out to be the biggest microbe source. Sizing and coating experiments showed that it is possible to improve hygiene of card board by chemically treated surface size and coating color.

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PURPOSE: To estimate the likelihood of axillary lymph node involvement for patients with early-stage breast cancer, based on a variety of clinical and pathological factors. METHODS: A retrospective analysis was done in hospital databases from 1999 to 2007. Two hundred thirty-nine patients were diagnosed with early-stage breast cancer. Predictive factors, such as patient age, tumor size, lymphovascular invasion, histological grade and immunohistochemical subtype were analyzed to identify variables that may be associated with axillary lymph node metastasis. RESULTS: Patients with tumors that are negative for estrogen receptor, progesterone receptor, and HER2 had approximately a 90% lower chance of developing lymph node metastasis than those with luminal A tumors (e.g., ER+ and/or PR+ and HER2-) - Odds Ratio: 0.11; 95% confidence interval: 0.01-0.88; p=0.01. Furthermore, the risk for lymph node metastasis of luminal A tumors seemed to decrease as patient age increased, and it was directly correlated with tumor size. CONCLUSION: The molecular classification of early-stage breast cancer using immunohistochemistry may help predicting the probability of developing axillary lymph node metastasis. Further studies are needed to optimize predictions for nodal involvement, with the aim of aiding the decision-making process for breast cancer treatment.

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This doctoral thesis describes the development work performed on the leachand purification sections in the electrolytic zinc plant in Kokkola to increase the efficiency in these two stages, and thus the competitiveness of the plant. Since metallic zinc is a typical bulk product, the improvement of the competitiveness of a plant was mostly an issue of decreasing unit costs. The problems in the leaching were low recovery of valuable metals from raw materials, and that the available technology offered complicated and expensive processes to overcome this problem. In the purification, the main problem was consumption of zinc powder - up to four to six times the stoichiometric demand. This reduced the capacity of the plant as this zinc is re-circulated through the electrolysis, which is the absolute bottleneck in a zinc plant. Low selectivity gave low-grade and low-value precipitates for further processing to metallic copper, cadmium, cobalt and nickel. Knowledge of the underlying chemistry was poor and process interruptions causing losses of zinc production were frequent. Studies on leaching comprised the kinetics of ferrite leaching and jarosite precipitation, as well as the stability of jarosite in acidic plant solutions. A breakthrough came with the finding that jarosite could precipitate under conditions where ferrite would leach satisfactorily. Based on this discovery, a one-step process for the treatment of ferrite was developed. In the plant, the new process almost doubled the recovery of zinc from ferrite in the same equipment as the two-step jarosite process was operated in at that time. In a later expansion of the plant, investment savings were substantial compared to other technologies available. In the solution purification, the key finding was that Co, Ni, and Cu formed specific arsenides in the “hot arsenic zinc dust” step. This was utilized for the development of a three-step purification stage based on fluidized bed technology in all three steps, i.e. removal of Cu, Co and Cd. Both precipitation rates and selectivity increased, which strongly decreased the zinc powder consumption through a substantially suppressed hydrogen gas evolution. Better selectivity improved the value of the precipitates: cadmium, which caused environmental problems in the copper smelter, was reduced from 1-3% reported normally down to 0.05 %, and a cobalt cake with 15 % Co was easily produced in laboratory experiments in the cobalt removal. The zinc powder consumption in the plant for a solution containing Cu, Co, Ni and Cd (1000, 25, 30 and 350 mg/l, respectively), was around 1.8 g/l; i.e. only 1.4 times the stoichiometric demand – or, about 60% saving in powder consumption. Two processes for direct leaching of the concentrate under atmospheric conditions were developed, one of which was implemented in the Kokkola zinc plant. Compared to the existing pressure leach technology, savings were obtained mostly in investment. The scientific basis for the most important processes and process improvements is given in the doctoral thesis. This includes mathematical modeling and thermodynamic evaluation of experimental results and hypotheses developed. Five of the processes developed in this research and development program were implemented in the plant and are still operated. Even though these processes were developed with the focus on the plant in Kokkola, they can also be implemented at low cost in most of the zinc plants globally, and have thus a great significance in the development of the electrolytic zinc process in general.

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Network externalities and two-sided markets in the context of web services and value creation is not very well discussed topic in academic literature. The explosive rise of the Internet users has created a strong base for many successful web services and pushed many firms towards e-business and online service based business models. Thus the subject of this thesis, the role of network externalities in value creating process of the commer-cial web service for two-sided international markets is very current and interesting topic to examine. The objective of this Master’s Thesis is to advance the study of network externalities from the viewpoint of two-sided markets and network effects as well as describe the value creation & value co-creation process in commercial web service business models. The main proposition suggests that the larger network of customers and the bigger number of users the web service is able to attract, the more value and stronger positive net-work externalities the service is able to create for each customer group. The empirical research of this study was implemented for commercial web service, targeted to Russian consumers and Finnish business users. The findings suggest that the size of the network is highly related to the experi-enced value of the customers and the whole value creation process of commercial web targeted for two-sided international markets varies from the value creation for one-sided or pure domestic markets.

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This article discusses, from the standpoint of cellular biology, the deterministic and indeterministic androgenesis theories. The role of the vacuole and of various types of stresses on deviation of the microspore from normal development and the point where androgenetic competence is acquired are examined. Based on extensive literature review and data on wheat studies from our laboratory, a model for androgenetic capacity of pollen grain is proposed. A two point deterministic model for in vitro androgenesis is our proposal for acquisition of androgenetic potential of the pollen grain: the first switch point would be early meiosis and the second switch point the uninucleate pollen stage, because the elimination of cytoplasmatic sporophytic determinants takes place at those two strategic moments. Any abnormality in this process allowing the maintenance of sporophytic informational molecules results in the absence of establishment of a gametophytic program, allowing the reactivation of the embryogenic process

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Transforming growth factor beta 1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) are important regulators of bone repair and regeneration. In this study, we examined whether TGF-β1 and BMP-2 expressions were delayed during bone healing in type 1 diabetes mellitus. Tibial fractures were created in 95 diabetic and 95 control adult male Wistar rats of 10 weeks of age. At 1, 2, 3, 4, and 5 weeks after fracture induction, five rats were sacrificed from each group. The expressions of TGF-β1 and BMP2 in the fractured tibias were measured by immunohistochemistry and quantitative reverse-transcription polymerase chain reaction, weekly for the first 5 weeks post-fracture. Mechanical parameters (bending rigidity, torsional rigidity, destruction torque) of the healing bones were also assessed at 3, 4, and 5 weeks post-fracture, after the rats were sacrificed. The bending rigidity, torsional rigidity and destruction torque of the two groups increased continuously during the healing process. The diabetes group had lower mean values for bending rigidity, torsional rigidity and destruction torque compared with the control group (P<0.05). TGF-β1 and BMP-2 expression were significantly lower (P<0.05) in the control group than in the diabetes group at postoperative weeks 1, 2, and 3. Peak levels of TGF-β1 and BMP-2 expression were delayed by 1 week in the diabetes group compared with the control group. Our results demonstrate that there was a delayed recovery in the biomechanical function of the fractured bones in diabetic rats. This delay may be associated with a delayed expression of the growth factors TGF-β1 and BMP-2.

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The main purpose ofthis study was to examine the effect ofintention on the sleep onset process from an electrophysiological point ofview. To test this, two nap conditions, the Multiple Sleep Latency Test (MSLT) and the Repeated Test of Sustained Wakefulness (RTSW) were used to compare intentional and inadvertent sleep onset. Sixteen female participants (aged 19-25) spent two non-consecutive nights in the sleep lab; however, due to physical and technical difficulties only 8 participants produced compete sets of data for analysis. Each night participants were given six nap opportunities. For three ofthese naps they were instructed to fall asleep (MSLT), for the remaining three naps they were to attempt to remain awake (RTSW). These two types of nap opportunities represented the conditions ofintentional (MSLT) and inadvertent (RTSW) sleep onset. Several other sleepiness, performance, arousal and questionnaire measures were obtained to evaluate and/or control for demand characteristics, subjective effort and mental activity during the nap tests. The nap opportunities were scored using a new 9 stage scoring system developed by Hori et al. (1994). Power spectral analyses (FFT) were also performed on the sleep onset data provided by the two nap conditions. Longer sleep onset latencies (approximately 1.25 minutes) were obseIVed in the RTSW than the MSLT. A higher incidence of structured mental activity was reported in the RTSW and may have been reflected in higher Beta power during the RTSW. The decent into sleep was more ragged in the RTSW as evidenced by an increased number shifts towards higher arousal as measured using the Hori 9 stage sleep scoring method. 1ll The sleep onset process also appears to be altered by the intention to remain awake, at least until the point ofinitial Stage 2 sleep (i.e. the first appearance of spindle activity). When only examining the final 4.3 minutes ofthe sleep onset process (ending with spindle activity), there were significant interactions between the type ofnap and the time until sleep onset for Theta, Alpha and Beta power. That is to say, the pattern of spectral power measurements in these bands differed across time as a function ofthe type ofnap. The effect ofintention however, was quite small (,,2 < .04) when compared to the variance which could be accounted for by the passage oftime (,,2 == .10 to .59). These data indicate that intention alone cannot greatly extend voluntary wakefulness if a person is sleepy. This has serious implications for people who may be required to perform dangerous tasks while sleepy, particularly for people who are in a situation that does not allow them the opportunity to engage in behavioural strategies in order to maintain their arousal.

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In this thesis, I examined the relevance of dual-process theory to understanding forgiveness. Specifically, I argued that the internal conflict experienced by laypersons when forgiving (or finding themselves unable to forgive) and the discrepancies between existing definitions of forgiveness can currently be best understood through the lens of dual-process theory. Dual-process theory holds that individuals engage in two broad forms of mental processing corresponding to two systems, here referred to as System 1 and System 2. System 1 processing is automatic, unconscious, and operates through learned associations and heuristics. System 2 processing is effortful, conscious, and operates through rule-based and hypothetical thinking. Different definitions of forgiveness amongst both lay persons and scholars may reflect different processes within each system. Further, lay experiences with internal conflict concerning forgiveness may frequently result from processes within each system leading to different cognitive, affective, and behavioural responses. The study conducted for this thesis tested the hypotheses that processing within System 1 can directly affect one's likelihood to forgive, and that this effect is moderated by System 2 processing. I used subliminal conditioning to manipulate System 1 processing by creating positive or negative conditioned attitudes towards a hypothetical transgressor. I used working memory load (WML) to inhibit System 2 processing amongst half of the participants. The conditioning phase of the study failed and so no conclusions could be drawn regarding the roles of System 1 and System 2 in forgiveness. The implications of dual-process theory for forgiveness research and clinical practice, and directions for future research are discussed.

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Use of short fibers as reinforcing fillers in rubber composites is on an increasing trend. They are popular due to the possibility of obtaining anisotropic properties, ease of processing and economy. In the preparation of these composites short fibers are incorporated on two roll mixing mills or in internal mixers. This is a high energy intensive time consuming process. This calls for developing less energy intensive and less time consuming processes for incorporation and distribution of short fibers in the rubber matrix. One method for this is to incorporate fibers in the latex stage. The present study is primarily to optimize the preparation of short fiber- natural rubber composite by latex stage compounding and to evaluate the resulting composites in terms of mechanical, dynamic mechanical and thermal properties. A synthetic fiber (Nylon) and a natural fiber (Coir) are used to evaluate the advantages of the processing through latex stage. To extract the full reinforcing potential of the coir fibers the macro fibers are converted to micro fibers through chemical and mechanical means. The thesis is presented in 7 chapters

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Se ocupa de los rasgos comunes de los textos de información, y cómo los conocimientos, habilidades y estrategias necesarios para la lectura y la escritura de estos textos son inseparables. El conocimiento de la estructura del texto y las características del lenguaje captados por el alumno en las clases de escritura se utilizan como ayuda en la comprensión de las clases de lectura. Del mismo, la forma de enseñar a encontrar la idea principal en un texto leído sirve para mejorar la capacidad de escribir. Por razones de organización y claridad, se ha dividido este libro en tipos de texto y estrategias diseñadas principalmente para la escritura, y estrategias que son en su mayoría solo para la lectura.

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En esta etapa del desarrollo de la alfabetización, la mayoría de los niños han comprendido sus conceptos fundamentales y ya saben hablar, leer y escribir para distintos tipos de oyentes y para distintos propósitos. Para la consolidación de estos conocimientos y la adquisición de nuevas habilidades necesitan contar con una amplia gama de textos y contextos, aprender a decodificar palabras desconocidas, deletrear palabras difíciles. El modelo de lectura y escritura compartida y guiada es la estrategia de enseñanza más idónea.

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Puede servir como referencia, cómo guía pedagógica o, bien cómo un recurso de estrategias y actividades prácticas utilizadas por los profesores en el aula. Describe los elementos de la estructura del texto y los rasgos más comunes del lenguaje poético y narrativo, define las características específicas de cada uno de estos géneros literarios, y las formas que adquieren textos y poesías. Se señala el modelo de lectura compartida y guiada como el más idóneo para la enseñanza y el aprendizaje de estos contenidos, pues permite a los alumnos actividades cómo hacer preguntas, comparar y reflexionar sobre lo que están leyendo.

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Está dividido en cuatro secciones, a lo largo de las cuales se proporciona orientación para la enseñanza y el aprendizaje de palabras y oraciones, se destaca la importancia de estos elementos para el aprendizaje por los niños de la lectura y la escritura, se hace un esbozo del proceso de alfabetización infantil desde el tercer hasta el sexto año de ingreso en la escuela, asimismo, se describe este proceso de desarrollo continuo de la alfabetización de los niños.

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Puede servir como referencia, cómo guía pedagógica o, bien cómo un recurso de estrategias y actividades prácticas utilizadas por los profesores en el aula. Describe los elementos de la estructura del texto y los rasgos más comunes del lenguaje poético y narrativo, define las características específicas de cada uno de estos géneros literarios, y las formas que adquieren textos y poesías. Se señala el modelo de lectura compartida y guiada como el más idóneo para la enseñanza y el aprendizaje de estos contenidos, pues permite a los alumnos actividades cómo hacer preguntas, comparar y reflexionar sobre lo que están leyendo.

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Para alumnos de primaria. Da toda la información importante, de la forma más clara y concisa posible, para aprender y desarrollar conocimientos de historia. Actividades divertidas tratan de hacer el aprendizaje más ameno.