Electric Arc Furnace slag (EAF): use in concrete for structural applications

L’industria siderurgica rappresenta una delle maggiori realtà produttive nel panorama mondiale, con una produzione globale di acciaio in continua crescita negli ultimi vent’anni. Nonostante le diverse tecniche disponibili, al giorno d’oggi la produzione avviene principalmente mediante due cicli: il “ciclo integrale” o il “ciclo elettrico”, ai quali si aggiungono le successive affinazioni in forno siviera. Oltre al materiale primario (acciaio), da tutti questi processi si origina anche un ingente quantitativo di materiale secondario, le cosiddette “scorie di acciaieria”. In ragione del processo produttivo, delle materie prime, delle modalità di gestione del forno, del tipo di acciaio, dei processi di raffreddamento post-scorifica e dei successivi trattamenti, esse si suddividono in diverse tipologie, ciascuna con le proprie caratteristiche chimico-fisiche, mineralogiche e prestazionali. Il riutilizzo delle scorie di acciaieria in sostituzione delle materie prime naturali in diverse applicazioni apporta notevoli vantaggi sia dal punto di vista economico e sociale che da quello ambientale. Un loro reimpiego contribuisce infatti alla diminuzione dei quantitativi da destinare a smaltimento in discarica nonché alla riduzione dello sfruttamento delle risorse naturali e degli impatti da esso derivanti, sia in termini ambientali che di tutela della biodiversità e del paesaggio. Per poter però garantire un loro corretto trattamento in previsione di un futuro reimpiego, anche le scorie di acciaieria sono soggette al rispetto di determinati standard normativi. Infatti, a seconda della classificazione, i processi di trattamento, registrazione e le verifiche di conformità risulteranno molto diversi ed una loro conoscenza ed interpretazione saranno quindi fondamentali per la corretta gestione di questo tipo di materiale. Il presente lavoro di ricerca intende dare un ulteriore contributo alle conoscenze sulle scorie di acciaieria, con un focus completo su produzione, proprietà, classificazione, gestione e riutilizzi finali. È stata dapprima condotta un’intensa attività di ricerca bibliografica riguardante diverse tipologie di scorie di acciaieria, al fine di approfondire ed analizzare le loro proprietà fisiche, chimiche, mineralogiche, prestazionali ed i relativi aspetti correlati ad un loro eventuale impatto ambientale. Ampio spazio è stato dedicato ai loro possibili riutilizzi, con un focus sul reimpiego nel settore delle costruzioni ed in particolare per la produzione di calcestruzzo. Verrà poi mostrato un quadro generale ed aggiornato sulla normativa nazionale, analizzando le diverse possibilità di classificazione e gli iter da esse derivanti, partendo dalla produzione ed approfondendo tutte le fasi fino all’ottenimento di un materiale conforme e commercializzabile. Vista l’eterogeneità delle scorie di acciaieria, è stato poi deciso di indagare lo stato dell’arte sulla loro produzione e gestione a livello nazionale e locale, con focus su Regione Lombardia (Italia) e Provincia di Brescia (Italia). Ciò ha inoltre permesso di individuare la tipologia di scoria più consona per lo sviluppo di una campagna sperimentale, parte finale della presente ricerca. La suddetta campagna sperimentale verte sul riutilizzo della scoria derivante dalla produzione di acciaio al carbonio in forno elettrico ad arco (la cosiddetta “EAFS-C”) come aggiunta nel calcestruzzo per applicazioni strutturali. In particolare, sono state dapprima progettate diverse miscele di calcestruzzo con l’aggiunta di scorie in parziale sostituzione dell’aggregato fine e grossolano naturale, in tre diverse percentuali (10, 25 e 50%). Queste miscele sono poi state analizzate mediante l’esecuzione di test per la caratterizzazione del materiale (proprietà reologiche e di resistenza), con l’aggiunta anche di test per la valutazione di alcuni aspetti legati alla durabilità del calcestruzzo.The iron and steel industry represents one of the largest production realities in the world, with global steel production steadily growing over the last two decades. Despite the different techniques available, production nowadays mainly takes place according to two cycles: the “integral cycle” or the “electric cycle”, to which subsequent refining in a ladle furnace is added. In addition to the primary material (steel), all these processes also generate a large amount of secondary materials, the so-called “iron- and steelmaking slags”. Depending on the production processes, the raw materials, the furnace management, the type of steel, the post-slagging cooling processes and the subsequent treatments, they are divided into different types, each with its own chemical-physical, mineralogical and performance characteristics. The reuse of iron- and steelmaking slags to replace natural raw materials brings considerable advantages from an economic, social and environmental point of view. In fact, their reuse contributes to reducing the quantities destined for disposal in landfills, the exploitation of natural resources and the resulting impacts, in terms of environment, biodiversity and landscape protection. However, in order to ensure their proper treatment for future reuse, iron- and steelmaking slags are also subjected to certain regulatory standards. In fact, depending on the classification, the treatment processes, registration and conformity assessments will be quite different and their knowledge and interpretation are therefore essential for the proper management of this type of materials. This research aims to provide a further contribution to the knowledge of iron- and steelmaking slags, with a comprehensive focus on production, properties, classification, management and final reuses. First of all, an intensive literature research was carried out on different types of iron- and steelmaking slags, in order to investigate and analyse their physical, chemical, mineralogical and performance properties, as well as aspects related to their possible environmental impact. Large space has been dedicated to their possible reuses, with a focus on reuse in the construction sector and in particular for concrete production. A general and updated overview of the national regulations will then be shown, analysing the different classification possibilities and the procedures deriving from them, starting from production and going through all the phases until a compliant and marketable material is obtained. Given the heterogeneity of iron- and steelmaking slags, it was then decided to investigate the state of the art on their production and management at a national and local level, focusing on the Lombardy Region (Italy) and the Province of Brescia (Italy). This also made it possible to identify the most suitable type of slag for the development of an experimental campaign, the final part of this research. The aforementioned experimental campaign concerns the reuse of slag from the production of carbon steel in electric arc furnaces (the so-called “EAFS-C”) as an addition in concrete for structural applications. Specifically, different concrete mixtures with the addition of slag as partial replacement of fine and coarse aggregate (in three different percentages, 10, 25 and 50%) were first designed. These mixtures were then analysed by carrying out tests for material characterisation (rheological and strength properties), with the addition of tests to assess aspects related to the durability of concrete

Association Between Plasma Monocyte Chemoattractant Protein-1 Concentration and Cardiovascular Disease Mortality in Middle-Aged Diabetic and Nondiabetic Individuals

OBJECTIVE Monocyte chemoattractant protein-1 (MCP-1/CCL2) is a chemokine involved into the pathogenesis of atherosclerosis and has prognostic value in the acute and chronic phases in patients with acute coronary syndromes. RESEARCH DESIGN AND METHODS MCP-1/CCL2 concentration was measured in plasma fractions of 363 middle-aged overweight/obese individuals (aged 61 \ub1 12 years, BMI 30.1 \ub1 6.6 kg/m2, 15% with type 2 diabetes, and 12% with impaired glucose tolerance) of a population survey carried out in 1990\u20131991 in Lombardy, Italy (Cremona Study), and cardiovascular disease (CVD) mortality was assessed in 2006 through Regional Health Registry files. RESULTS At baseline MCP-1/CCL2 was increased in individuals with type 2 diabetes (P < 0.05) and showed significant correlations with biochemical risk markers of atherosclerosis. After 15 years, among the 363 subjects, there were 82 deaths due to CVD. In univariate analysis age, sex, fasting glucose and insulin, fibrinogen, glucose tolerance status, smoking habit, and MCP-1/CCL2 were associated with CVD mortality. Age, sex, fasting serum glucose, MCP-1/CCL2, and smoking habit maintained an independent association with CVD mortality in multiple regression analysis. In a subgroup of 113 subjects in whom data for C-reactive protein (CRP) were available, its level was not predictive of CVD mortality. CONCLUSIONS In middle-aged overweight/obese individuals MCP-1/CCL2 was independently associated with CVD mortality. Further studies will be necessary to establish its role as a surrogate biomarker and as a potential therapeutic target

El traductor/intérprete en los códigos nacionales italianos y argentinos

Los códigos argentinos nacionales —civil y comercial, penal, procesal civil y comercial y procesal penal— mencionan dos figuras profesionales cuyo origen es contemporáneo y su desarrollo paralelo al proceso de conquista y colonización de los territorios americanos por parte de los españoles: el intérprete y el traductor.Sin embargo, ambas expresiones, que hoy designan a dos profesiones distintas y bien diferenciadas, se confunden entre los textos -y en algunos casos, hasta en el mismo cuerpo legal-, se mezclan, se intercambian, se utilizan como sinónimos.Una confusión similar ocurriría en los homónimos códigos italianos y todo ello hallaría una primera explicación en el marco del concepto de multivocidad de los términos jurídicos (Goldschmidt, 1996), así como en un cierto comprensible desconocimiento del legislador, tanto por el momento histórico de la elaboración de los cuerpos legales, como por la marginalidad que la traducción/interpretación en general ocupa desde siempre en nuestra cultura occidental

No sólo de traducciones vive el traductor. Experiencias pedagógicas de traducción para técnicos

Resumimos aquí la experiencia pedagógica de la enseñanza de lenguaje sectorial a estudiantes terciarios de “Técnica Bancaria y Comercio Exterior” (de 1992 a 2001), que incluyó sucesivamente el desarrollo de las cuatro habilidades comunicativas, la traducción y la lectocomprensión de textos específicos. Se plantean las disyuntivas y los problemas registrados en cada una de las propuestas y la conclusión general de que no es posible enseñar-aprender la traducción ni las cuatro habilidades en las condiciones señaladas.Fil: Piemonti, María Gabriela. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Lenguas; Argentin

Effect of Stakeholder Attitudes on the Optimization of Watershed Conservation Practices

Indiana University-Purdue University Indianapolis (IUPUI)Land use alterations have been major drivers for modifying hydrologic cycles in many watersheds nationwide. Imbalances in this cycle have led to unexpected or extreme changes in flood and drought patterns and intensities, severe impairment of rivers and streams due to pollutants, and extensive economic losses to affected communities. Eagle Creek Watershed (ECW) is a typical Midwestern agricultural watershed with a growing urban land-use that has been affected by these problems. Structural solutions, such as ditches and tiles, have helped in the past to reduce the flooding problem in the upland agricultural area. But these structures have led to extensive flooding and water quality problems downstream and loss of moisture storage in the soil upstream. It has been suggested that re-naturalization of watershed hydrology via a spatially-distributed implementation of non-structural and structural conservation practices, such as cover crops, wetlands, riparian buffers, grassed waterways, etc. will help to reduce these problems by improving the upland runoff (storing water temporally as moisture in the soil or in depression storages). However, spatial implementation of these upland storage practices poses hurdles not only due to the large number of possible alternatives offered by physical models, but also by the effect of tenure, social attitudes, and behaviors of landowners that could further add complexities on whether and how these practices are adopted and effectively implemented for benefits. This study investigates (a) how landowner tenure and attitudes can be used to identify promising conservation practices in an agricultural watershed, (b) how the different attitudes and preferences of stakeholders can modify the effectiveness of solutions obtained via classic optimization approaches that do not include the influence of social attitudes in a watershed, and (c) how spatial distribution of landowner tenure affects the spatial optimization of conservation practices on a watershed scale. Results showed two main preferred practices, one for an economic evaluation (filter strips) and one for an environmental perspective (wetlands). A land tenure comparison showed differences in spatial distribution of systems considering all the conservation practices. It also was observed that cash renters selected practices will provide a better cost-revenue relation than the selected optimal solution

A web-based software tool for participatory optimization of conservation practices in watersheds

WRESTORE (Watershed Restoration Using Spatio-Temporal Optimization of Resources) is a web-based, participatory planning tool that can be used to engage with watershed stakeholder communities, and involve them in using science-based, human-guided, interactive simulation–optimization methods for designing potential conservation practices on their landscape. The underlying optimization algorithms, process simulation models, and interfaces allow users to not only spatially optimize the locations and types of new conservation practices based on quantifiable goals estimated by the dynamic simulation models, but also to include their personal subjective and/or unquantifiable criteria in the location and design of these practices. In this paper, we describe the software, interfaces, and architecture of WRESTORE, provide scenarios for implementing the WRESTORE tool in a watershed community's planning process, and discuss considerations for future developments

Interactive genetic algorithm for user-centered design of distributed conservation practices in a watershed: An examination of user preferences in objective space and user behavior

Interactive Genetic Algorithms (IGA) are advanced human-in-the-loop optimization methods that enable humans to give feedback, based on their subjective and unquantified preferences and knowledge, during the algorithm's search process. While these methods are gaining popularity in multiple fields, there is a critical lack of data and analyses on (a) the nature of interactions of different humans with interfaces of decision support systems (DSS) that employ IGA in water resources planning problems and on (b) the effect of human feedback on the algorithm's ability to search for design alternatives desirable to end-users. In this paper, we present results and analyses of observational experiments in which different human participants (surrogates and stakeholders) interacted with an IGA-based, watershed DSS called WRESTORE to identify plans of conservation practices in a watershed. The main goal of this paper is to evaluate how the IGA adapts its search process in the objective space to a user's feedback, and identify whether any similarities exist in the objective space of plans found by different participants. Some participants focused on the entire watershed, while others focused only on specific local subbasins. Additionally, two different hydrology models were used to identify any potential differences in interactive search outcomes that could arise from differences in the numerical values of benefits displayed to participants. Results indicate that stakeholders, in comparison to their surrogates, were more likely to use multiple features of the DSS interface to collect information before giving feedback, and dissimilarities existed among participants in the objective space of design alternatives

Bioengineering the Pancreas: Cell-on-Scaffold Technology

Nowadays, type I diabetes mellitus is a pathology afflicting millions of people globally with a dramatic assessment in the next future. Current treatments including exogenous insulin, pancreas transplantation and islets transplantation, are not free from important lifelong side effects. In the last decade, tissue engineering and regenerative medicine have shown encouraging results about the possibility to produce a functional bioengineered pancreas. Among many technologies, decellularization offers the opportunity to produce an organ-specific acellular matrix that could subsequently repopulate with endocrine cellular population. Herein, we aim to review the state-of-art and this technology highlighting the diabetes burden for the healthcare system and the major achievements toward the manufacturing of a bioengineered pancreas obtained by cell-on-scaffold technology

Interactive Genetic Algorithms for watershed planning : an investigation of usability and human-centered design

Degradation of watersheds is a major concern in areas where adverse climate effects and unsustainable use of the natural resources have caused extensive stresses to watershed systems (e.g., increased floods, increased droughts, worsened in-stream water quality) through the years. While considerable efforts are being made to generate technical solutions that focus on plans of spatially-distributed conservation practices (e.g., Wetlands, Filter Strips, Grassed Waterways, Crop Management practices, etc.) for restoration of existing conditions in the watersheds, adoption and implementation of these solutions require a better understanding of constraints faced by affected stakeholders and decision makers. Participatory modeling and design approaches have, as a result, become popular in the recent past to support a community's engagement during the modeling process and during development of potential scenarios of plans (or, design alternatives). And now, with new and ongoing developments in Web 2.0 technologies, there is an even greater need for research that examines how large number of stakeholders can be engaged in the development of design alternatives via the internet-based, decision support environments. The overarching goal of this research is to investigate how stakeholder participation ("humans") and Interactive Genetic Algorithms ("computer") can be coupled in a web-based watershed decision support system (DSS) called WRESTORE (Watershed REstoration using Spatio Temporal Optimization of REsources- http://wrestore.iupui.edu/), in order to generate user-preferred design alternatives of distributed conservation practices on a watershed landscape. An important component of this goal is to also improve the understanding of how human behavior on the graphical user interface (GUI) of the DSS can be observed and evaluated in real-time, and then learned from to further improve the performance of the underlying search algorithm. Four specific objectives were addressed in this work to accomplish the overall goal: • Objective 1: Observe interactions of multiple users with the GUI of a web-based watershed DSS (WRESTORE, http://wrestore.iupui.edu/) during interactive search experiments, and then use Usability metrics (response times, clicking events and confidence levels) to evaluate the differences and similarities in user behaviors and interactions. • Objective 2: Examine relationships between the type of users (e.g., stakeholders versus surrogates), the Usability metrics, and patterns in the watershed-scale plans of conservation practices generated by the multi-objective Interactive Genetic Algorithm embedded in WRESTORE. • Objective 3: Examine relationships between the type of users, the Usability metrics, and patterns in the user-preferred, sub-basin-scale plans of conservation practices generated by the multi-objective Interactive Genetic Algorithm embedded in WRESTORE. • Objective 4: Develop and test novel human-guided search operators that adaptively learn for patterns in user-preferred alternatives generated by the multi-objective Interactive Genetic Algorithm, and, as a result, improve the convergence rate of the search algorithm for generating design alternatives that conserve these learned patterns. Results show that there is a clear difference on how different types of users interact with the Interactive Optimization system. The observed relationship between confidence levels, time spent on a task, and number of mouse clicking events, indicated that participants who were able to use the WRESTORE GUI to gather more information and had a higher rate of time per number of clicks, tended to increase their levels of self-confidence in their own feedback. Also, when engaging with watershed stakeholders versus non-stakeholders (or, surrogates), 67% of the stakeholder participants steadily increased their average self-confidence levels as they continued to interact with the tool, in contrast to only 29% of surrogate participants who also showed an increase in their self-confidence levels through time. Such usability and confidence level evaluations provide assessments on which participant was potentially generating reliable feedback data for the search algorithm to use. An analysis of design alternatives generated by the individuals in both stakeholder and non-stakeholder groups showed that a majority (67%) of the stakeholder participants found a higher percentage (on and average 52%) of preferred design alternatives via the interactive search process. Also, users who were focused on assessing the suitability of design alternatives for the entire watershed trended to demonstrate a bias for one of the watershed-scale objective functions. In contrast, users, who were focused on assessing the suitability of design alternatives at only a few local sub-basins in the watershed, did not demonstrate any clear bias for any one of the watershed-scale objective functions. Additionally, patterns were observed in the design of decision alternatives generated by the human-centered search process, which further divulged potential user preferences related to the decision space for example, whether a specific participant preferred a certain practice over another, or a certain location over another for a specific practice. Finally, to improve the convergence rates of the Interactive Genetic Algorithm in WRESTORE, we investigated whether observed patterns in decisions (especially, when users were focused on local sub-regions of the watershed) can be used to improve the search for user-desire designs. A novel Interactive Genetic Algorithm with adaptive, human-guided, selection, crossover and mutation operators was proposed. The new algorithm was tested with six types of simulated participants (three deterministic and three probabilistic users) developed from the feedback data of three real participants. Results of search experiments with the novel adaptive IGA operators indicated a faster convergence than the default IGA, for two out of three deterministic simulated users. However, none of the probabilistic user showed a convergence different than the default values. This indicates that while current results indicate promise, there is need for additional research on adaptive, human-guided IGA operators, especially when noisy/stochastic users participate in the search. Additionally, adaptation of search operators have the potential to improve convergence rates when participatory design is done via Interactive Genetic Algorithms

Detection and Characterization of CD8+ Autoreactive Memory Stem T Cells in Patients With Type 1 Diabetes

Stem memory T cells (Tscm) constitute the earliest developmental stage of memory T cells, displaying stem cell–like properties, such as self-renewal capacity. Their superior immune reconstitution potential has sparked interest in cancer immune therapy, vaccine development, and immune reconstitution, whereas their role in autoimmunity is largely unexplored. Here we show that autoreactive CD8+ Tscm specific for β-cell antigens GAD65, insulin, and IGRP are present in patients with type 1 diabetes (T1D). In vitro, the generation of autoreactive Tscm from naive precursors required the presence of the homeostatic cytokine interleukin-7 (IL-7). IL-7 promotes glucose uptake via overexpression of GLUT1 and upregulation of the glycolytic enzyme hexokinase 2. Even though metabolism depends on glucose uptake, the subsequent oxidation of pyruvate in the mitochondria was necessary for Tscm generation from naive precursors. In patients with T1D, high expression of GLUT1 was a hallmark of circulating Tscm, and targeting glucose uptake via GLUT1 using the selective inhibitor WZB117 resulted in inhibition of Tscm generation and expansion. Our results suggest that autoreactive Tscm are present in patients with T1D and can be selectively targeted by inhibition of glucose metabolism