887 resultados para SELF-SUSTAINING PROCESS
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Practically since settlement of the state, Iowa trout streams had to be stocked to maintain a trout population. But improvements in water quality are leading to healthier, self-sustaining trout populations - and local communities are reaping the benefits.
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Among the most common pollutants that enter the environment after passing municipal wastewater treatment are estrogens, especially the synthetic 17α-ethinylestradiol that is used in oral contraceptives. Estrogens are potent endocrine disruptors at concentrations frequently observed in surface waters. However, new genetic analyses suggest that some fish populations can be self-sustaining even in heavily polluted waters. We now need to understand the basis of this tolerance.
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FY2007 was a productive year for the Iowa Grape and Wine Development Commission. Fourteen proposals were recommended for funding totaling over $390,000 in outlays. Included in the approved proposals were funds for the establishment and staffing of a Midwest Grape and Wine Institute at Iowa State University, a newly created viticulturist position at Des Moines Area Community College, funding for the first annual Mid-American Wine Competition, and marketing and promotion of four regional cooperative wine events and one wine trail. Commission funding supported a survey of commercial wine producers and grape growers and a new brochure on Iowa’s vineyards. A committee was formed to provide details for a Scholarship Program to aid vineyard and winery staff with the expenses of accredited coursework. Based on the survey conducted and from other governmental and industry sources, the Iowa grape and wine industry appears to continue to be very viable and growth continues at a strong pace. Wine produced in the state for 2007 was estimated at a market value in excess of $12.3 million. A tabulation of the budget revealed that just over $800,000 in wine gallonage tax appropriations have been received into the Grape and Wine Development Fund from 15 FY2003 through FY2007. Expenditures have totaled just over $607,000 during that same time. Just over 80% of expenditures have gone to “Technical” spending. Over time, funds invested in “Technical” programs will translate into an increasingly educated and institutionally-supported industry. Local, regional, and statewide events also appear to be increasing in popularity and the Commission plans to continue and increase support for these events. It is hoped the Scholarship Program will be up and running and funding will need to be appropriated for that project. The Commission also believes many projects and events will become more and more self sustaining as they develop and mature. As they continue to support Iowa’s grape and wine industry, the members of the Commission look forward to working with individuals, commercial enterprises, state and federal agencies, and industry-sponsored institutions in the upcoming year and in years to come.
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Career interventions for adults frequently include personality assessment. Personality in career counseling contexts should no longer be considered as vocational personality associated with personality interests but, rather, as a set of dispositions that has an impact on several vocational and career-related outcomes, such as work engagement, work satisfaction, job performance, etc. Although the relationship between personality and the vocational and career related outcomes is not direct, it might certainly be mediated by several regulatory processes, such as work adaptability, and moderated by contextual and environmental factors. Personality assessment initiates an individual's self-regulatory process and contributes to the overall effectiveness of career interventions when feedback is individualized and stimulates a deconstruction, reconstruction, and co-construction of the vocational or multiple self-concept. Personality assessments can also promote the reconstruction of a self-concept more aligned with the perception of the environment about the personality of the counselee, strengthening the reality principle allowing more rational and controlled choices. In addition, some specific personality profiles, such as having high levels of neuroticism and low levels of conscientiousness, can be considered as risk factors frequently leading to career decision-making difficulties. Moreover, people with low conscientiousness benefit less from career interventions, so special attention should be devoted to counselees having that characteristic. Two case studies are provided to illustrate these important aspects of personality assessment in career interventions.
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CD40L is one of the key molecules bridging the activation of specific T cells and the maturation of professional and nonprofessional antigen-presenting cells including B cells. CD4(+) T cells have been regarded as the major T-cell subset that expresses CD40L upon cognate activation; however, we demonstrate here that a putative CD8(+) helper T-cell subset expressing CD40L is induced in human and murine CD8(+) T cells in vitro and in mice immunized with antigen-pulsed dendritic cells. IL-12 and STAT4-mediated signaling was the major instructive cytokine signal boosting the ability of CD8(+) T cells to express CD40L both in vitro and in vivo. Additionally, TCR signaling strength modulated CD40L expression in CD8(+) T cells after primary differentiation in vitro as well as in vivo. The induction of CD40L in CD8(+) T cells regulated by IL-12 and TCR signaling may enable CD8(+) T cells to respond autonomously of CD4(+) T cells. Thus, we propose that under proinflammatory conditions, a self-sustaining positive feedback loop could facilitate the efficient priming of T cells stimulated by high affinity peptide displaying APCs.
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The dynamical properties ofshaken granular materials are important in many industrial applications where the shaking is used to mix, segregate and transport them. In this work asystematic, large scale simulation study has been performed to investigate the rheology of dense granular media, in the presence of gas, in a three dimensional vertical cylinder filled with glass balls. The base wall of the cylinder is subjected to sinusoidal oscillation in the vertical direction. The viscoelastic behavior of glass balls during a collision, have been studied experimentally using a modified Newton's Cradle device. By analyzing the results of the measurements, using numerical model based on finite element method, the viscous damping coefficient was determinedfor the glass balls. To obtain detailed information about the interparticle interactions in a shaker, a simplified model for collision between particles of a granular material was proposed. In order to simulate the flow of surrounding gas, a formulation of the equations for fluid flow in a porous medium including particle forces was proposed. These equations are solved with Large Eddy Simulation (LES) technique using a subgrid-model originally proposed for compressible turbulent flows. For a pentagonal prism-shaped container under vertical vibrations, the results show that oscillon type structures were formed. Oscillons are highly localized particle-like excitations of the granular layer. This self-sustaining state was named by analogy with its closest large-scale analogy, the soliton, which was first documented by J.S. Russell in 1834. The results which has been reportedbyBordbar and Zamankhan(2005b)also show that slightly revised fluctuation-dissipation theorem might apply to shaken sand, which appears to be asystem far from equilibrium and could exhibit strong spatial and temporal variations in quantities such as density and local particle velocity. In this light, hydrodynamic type continuum equations were presented for describing the deformation and flow of dense gas-particle mixtures. The constitutive equation used for the stress tensor provides an effective viscosity with a liquid-like character at low shear rates and a gaseous-like behavior at high shear rates. The numerical solutions were obtained for the aforementioned hydrodynamic equations for predicting the flow dynamics ofdense mixture of gas and particles in vertical cylindrical containers. For a heptagonal prism shaped container under vertical vibrations, the model results were found to predict bubbling behavior analogous to those observed experimentally. This bubbling behavior may be explained by the unusual gas pressure distribution found in the bed. In addition, oscillon type structures were found to be formed using a vertically vibrated, pentagonal prism shaped container in agreement with computer simulation results. These observations suggest that the pressure distribution plays a key rolein deformation and flow of dense mixtures of gas and particles under vertical vibrations. The present models provide greater insight toward the explanation of poorly understood hydrodynamic phenomena in the field of granular flows and dense gas-particle mixtures. The models can be generalized to investigate the granular material-container wall interactions which would be an issue of high interests in the industrial applications. By following this approach ideal processing conditions and powder transport can be created in industrial systems.
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Asiakaslähtöinen liiketoimintatapa on voimakkaasti valtaamassa alaa tuote- ja tuotanto-orientoituneelta. Tuotteiden erinomaisuus koetaan markkinoilla yhä enenevässä määrin itsestään selvyydeksi. Prosessien tehokas hallitseminen ja asiakkaan kokeman lisäarvon muodostaminen ovat muodostuneet ratkaisevimmaksi kilpailuedun luojaksi. Toimitusketjun hallinnalla on tämän kilpailuedun muodostumisessa ratkaiseva rooli. Diplomityö käsittelee toimitusketjun hallinnan tarjoamia mahdollisuuksia kehittää kohdeyrityksen tukkujakelukanavaa. Työssä pureudutaan toimitusketjun ohjauksen ja sähköisen liiketoiminnan mukanaan tuomien mahdollisuuksien hyödyntämiseen. Tärkeinä kehitystyön menetelminä esitetään toimitusketjun yhteistyön tiivistäminen ja informaation integraatio sekä näiden merkitys toimitusketjussa esiintyvän kysynnän piiskavaikutuksen vähentämiseksi.Työn empiirisen osan tuloksena on luotu kuvaus tutkitusta jakelukanavasta välillä loppuasiakas – kohdeyritys, sen toimitusketjun ohjauksesta ja toteutuneesta toiminnasta. Tämän perusteella on jakelukanavalle luotu kehitysmalli. Malli pitää sisällään viitekehyksen toimitusketjun ohjaukselle, käytännön toimenpide-ehdotukset ja saavutettavien hyötyjen arvioinnin.
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We have studied how leaders emerge in a group as a consequence of interactions among its members. We propose that leaders can emerge as a consequence of a self-organized process based on local rules of dyadic interactions among individuals. Flocks are an example of self-organized behaviour in a group and properties similar to those observed in flocks might also explain some of the dynamics and organization of human groups. We developed an agent-based model that generated flocks in a virtual world and implemented it in a multi-agent simulation computer program that computed indices at each time step of the simulation to quantify the degree to which a group moved in a coordinated way (index of flocking behaviour) and the degree to which specific individuals led the group (index of hierarchical leadership). We ran several series of simulations in order to test our model and determine how these indices behaved under specific agent and world conditions. We identified the agent, world property, and model parameters that made stable, compact flocks emerge, and explored possible environmental properties that predicted the probability of becoming a leader.
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A study is presented of the formation and optical properties of polymeric heterostructures from poly(p-phenylene vinylene) (PPV) and poly(o-methoxyaniline) (POMA) produced via the self-assembly technique. POMA layers were obtained in a non self-limiting process from its emeraldine salt, semiconducting form in HCl solution. Thermal conversion of PPV was performed at low temperatures with the substitution of the counter-ion Cl in the PPV precursor by a long sulfonic chain, the dodecylbenzenesulfonate (DBS) ion. The optical properties of PPV films converted in this way are not affected by POMA, which can be used as transparent electrode of PPV luminescent devices.
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Nonnative brook trout Salvelinus fontinalis are abundant in Pine Creek and its main tributary, Bogard Spring Creek, California. These creeks historically provided the most spawning and rearing habitat for endemic Eagle Lake rainbow trout Oncorhynchus mykiss aquilarum. Three-pass electrofishing removal was conducted in 2007–2009 over the entire 2.8-km length of Bogard Spring Creek to determine whether brook trout removal was a feasible restoration tool and to document the life history characteristics of brook trout in a California meadow stream. After the first 2 years of removal, brook trout density and biomass were severely reduced from 15,803 to 1,192 fish/ha and from 277 to 31 kg/ha, respectively. Average removal efficiency was 92–97%, and most of the remaining fish were removed in the third year. The lack of a decrease in age-0 brook trout abundance between 2007 and 2008 after the removal of more than 4,000 adults in 2007 suggests compensatory reproduction of mature fish that survived and higher survival of age-0 fish. However, recruitment was greatly reduced after 2 years of removal and is likely to be even more depressed after the third year of removal assuming that immigration of fish from outside the creek continues to be minimal. Brook trout condition, growth, and fecundity indicated a stunted population at the start of the study, but all three features increased significantly every year, demonstrating compensatory effects. Although highly labor intensive, the use of electrofishing to eradicate brook trout may be feasible in Bogard Spring Creek and similar small streams if removal and monitoring are continued annually and if other control measures (e.g., construction of barriers) are implemented. Our evidence shows that if brook trout control measures continue and if only Eagle Lake rainbow trout are allowed access to the creek, then a self-sustaining population ofEagle Lake rainbow trout can become reestablished
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Introduction. This study presents the results of the implementation process of portfolio in the course of four consecutive years. The plan includes three phases (initiation, development and consolidation). The sample is 480 students studying the first year of nursing at the University of Girona. The objective is to evaluate the effectiveness of the instrument and achieve its construction in a self-regulated process. Subjects and methods. The proposed methodology is based on the sequential triangulation between methods. The study of the same empirical unit it’s used two investigation strategies, quantitative and qualitative. Study 1: quantitative, descriptive, longitudinal and prospective. The statistical analysis of paired data for continuous variables that follow a normaldistribution is made with t Student-Fisher test. The correlation between two numerical variables is used the Pearson correlation index. Study 2: qualitative, uses the discussion groups and topics. For textual data analysis is used Atlas.ti. Results. The final score for students who prepare the portfolio is higher (7.78) than the score who do not prepare (7) (p ≤ 0.001). A significant correlation exists between the portfolio score and final score (p ≤ 0.001). The trend study showsa greater sensitivity of the instrument assessment. Conclusion. The final design of the portfolio is characterized by mixed, flexible and encourages the student reflection and empowers the reflection on the continuum of learning
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Biojäte soveltuu erinomaisesti biokaasuprosessin raaka-aineeksi sisältämänsä runsaan or-gaanisen aineksen vuoksi. Bioetanoliprosessin raaka-aineeksi se soveltuu, koska biojäte sisäl-tää runsaasti tärkkelystä sekä selluloosaa. Tässä työssä tutkittiin laskennallisesti bioetanoli-, biokaasu- sekä näiden yhdistelmäprosessin energia- ja hiilidioksiditaseita kirjallisuuden tietoihin pohjautuen. Biokaasuprosessista lopputuotteena saatavan biometaanin käyttäminen bensiiniä korvaavana liikennepolttoaineena tuottaa jo pelkästään palamistuotteena syntyvän hiilidioksidin säästöinä 62 kg/tbiojätettä. Energian suhteen biokaasuprosessi on selvästi yliomavaraisin kaikista kolmesta prosessista, vaikka energiankulutukseen huomioidaan myös jalostuksen tarvitsema sähkönku-lutus. Biokaasuprosessissa oma käyttö on alle 20 % lopputuotteen lämpöarvosta, yhdistelmä-prosessin osalta luku on 4 %-yks alhaisempi.
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Kirjallisuusarvostelu
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The condensation rate has to be high in the safety pressure suppression pool systems of Boiling Water Reactors (BWR) in order to fulfill their safety function. The phenomena due to such a high direct contact condensation (DCC) rate turn out to be very challenging to be analysed either with experiments or numerical simulations. In this thesis, the suppression pool experiments carried out in the POOLEX facility of Lappeenranta University of Technology were simulated. Two different condensation modes were modelled by using the 2-phase CFD codes NEPTUNE CFD and TransAT. The DCC models applied were the typical ones to be used for separated flows in channels, and their applicability to the rapidly condensing flow in the condensation pool context had not been tested earlier. A low Reynolds number case was the first to be simulated. The POOLEX experiment STB-31 was operated near the conditions between the ’quasi-steady oscillatory interface condensation’ mode and the ’condensation within the blowdown pipe’ mode. The condensation models of Lakehal et al. and Coste & Lavi´eville predicted the condensation rate quite accurately, while the other tested ones overestimated it. It was possible to get the direct phase change solution to settle near to the measured values, but a very high resolution of calculation grid was needed. Secondly, a high Reynolds number case corresponding to the ’chugging’ mode was simulated. The POOLEX experiment STB-28 was chosen, because various standard and highspeed video samples of bubbles were recorded during it. In order to extract numerical information from the video material, a pattern recognition procedure was programmed. The bubble size distributions and the frequencies of chugging were calculated with this procedure. With the statistical data of the bubble sizes and temporal data of the bubble/jet appearance, it was possible to compare the condensation rates between the experiment and the CFD simulations. In the chugging simulations, a spherically curvilinear calculation grid at the blowdown pipe exit improved the convergence and decreased the required cell count. The compressible flow solver with complete steam-tables was beneficial for the numerical success of the simulations. The Hughes-Duffey model and, to some extent, the Coste & Lavi´eville model produced realistic chugging behavior. The initial level of the steam/water interface was an important factor to determine the initiation of the chugging. If the interface was initialized with a water level high enough inside the blowdown pipe, the vigorous penetration of a water plug into the pool created a turbulent wake which invoked the chugging that was self-sustaining. A 3D simulation with a suitable DCC model produced qualitatively very realistic shapes of the chugging bubbles and jets. The comparative FFT analysis of the bubble size data and the pool bottom pressure data gave useful information to distinguish the eigenmodes of chugging, bubbling, and pool structure oscillations.
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Asthma is characterized by reversible airway obstruction, airway hyperresponsiveness, and airway inflammation. Although our understanding of its pathophysiological mechanisms continues to evolve, the relative contributions of airway hyperresponsiveness and inflammation are still debated. The first mechanism identified as important for asthma was bronchial hyperresponsiveness. In a second step, asthma was recognized also as an inflammatory disease, with chronic inflammation inducing structural changes or remodeling. However, persistence of airway dysfunction despite inflammatory control is observed in chronic severe asthma of both adults and children. More recently, a potential role for epithelial-mesenchymal communication or transition is emerging, with epithelial injury often resulting in a self-sustaining phenotype of wound repair modulation by activation/reactivation of the epithelial-mesenchymal trophic unit, suggesting that chronic asthma can be more than an inflammatory disease. It is noteworthy that the gene-environmental interactions critical for the development of a full asthma phenotype involve processes similar to those occurring in branching morphogenesis. In addition, a central role for airway smooth muscle in the pathogenesis of the disease has been explored, highlighting its secretory function as well as different intrinsic properties compared to normal subjects. These new concepts can potentially shed light on the mechanisms underlying some asthma phenotypes and improve our understanding of the disease in terms of the therapeutic strategies to be applied. How we understand asthma and its mechanisms along time will be the focus of this overview.