Influência da substituição de areia natural por pó de pedra no comportamento mecânico, microestrutural e eletroquímico de concretos

The construction industry is one of the largest consumers of natural raw materials, and concrete is considered today the most used material wide. This accentuated consumption of natural resources has generated concern with the preservation of the environment, and has motivated various studies related to the use of resid ues, which can partially or entirely substitute, with satisfactory performance, some materials such as the aggregate, and in so doing, decrease the impact on the environment caused by the produced residues. Research has been done to better understand and improve the microstructure of concrete, as well as to understand the mechanism of corrosion in reinforced steel. In this context, this work was developed aiming at discovering the influence of the substitution of natural sand by artificial sand, with rega rd to mechanical resistance, microstructure, and durability. To obtain the electrochemical parameters, an adaptation was made to the galvanostatic electrochemical method to study the corrosion in reinforced steel. Concretes of categories 20 MPa and 40 MPa were produced, containing natural sand, and concretes of the same categories were produced with artificial sand substituting the natural sand, and with the addition of sodium nitrate and sodium chloride. Due to the use of rock dust reject (artificial sand), an evaluation was made of its environmental risk. The results indicate that the concretes of category 20 MPa present a better performance than the concrete made with natural sand, thus making it a viable substitute. For the category 40 MPa, the better performance is from the concrete containing natural sand. The adaptation of the galvanostatic electrochemical technique to the study of the corrosion of reinforced steel within concrete proved to be valid for obtaining electrochemical parameters with a high degree of reliability, considering the number of degrees of freedom

Unraveling the performance of dispersion-corrected functionals for the accurate description of weakly bound natural polyphenols

Long-range non-covalent interactions play a key role in the chemistry of natural polyphenols. We have previously proposed a description of supramolecular polyphenol complexes by the B3P86 density functional coupled with some corrections for dispersion. We couple here the B3P86 functional with the D3 correction for dispersion, assessing systematically the accuracy of the new B3P86-D3 model using for that the well-known S66, HB23, NCCE31, and S12L datasets for non-covalent interactions. Furthermore, the association energies of these complexes were carefully compared to those obtained by other dispersion-corrected functionals, such as B(3)LYP-D3, BP86-D3 or B3P86-NL. Finally, this set of models were also applied to a database composed of seven non-covalent polyphenol complexes of the most interest.

Natural plant polyphenols for alleviating oxidative damage in man: Current status and future perspectives

The balance between oxidation and reduction is important for maintaining a healthy biological system. Oxidative stress results from an imbalance between excessive formation of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) and limited endogenous defense systems, and this imbalance can adversely alter lipids, proteins and DNA, causing a number of human diseases. Thus, exogenous antioxidants that can neutralize the effect of free radicals are needed to diminish the cumulative effects of oxidative damage over human life span. Current research reveals that phenolic compounds in plants possess high antioxidant activity and free radical scavenging capacity and can prevent the body from oxidative damage over human life span. This review focuses on the present understanding of free radicals and antioxidants and their importance in human health and disease. Information about the chemical features of free radicals as well as their deleterious effects on cell structures is reviewed. The chemical structure and anti-oxidative mechanisms of essential polyphenols and their potential health benefits are presented. In addition, the limitation of natural antioxidants and a perspective on likely future trends in this field are also discussed.

Paisagem, um patrimônio esquecido: subsídios para a construção de uma metodologia de valoração e proteção do cenário natural litorâneo

The so-called "residential tourism" came to intensify the previous occupation of the coastal zones, characterized by traditional beach houses, and brought significant consequences for their spatial configuration, and especially for its scenic value of the landscape. Although there is the intention to regulate the activities of enterprising groups by some legal instruments to control the use and occupation of land, and to contain some negative effects, the actions of government are still inefficient in trying to follow the implications on the landscape from the accelerated growth of the real estate and touristic sectors. Supported in the speech of economic development and income generation, public managers prioritize areas to attract tourists to the detriment of preserving important physical attributes of the natural environment that contribute significantly to the quality of life. The result can be noticed in the use of natural elements as one of the major components in the land valorization, and in the immediate attraction of investors and enterprising. Therefore, the objective of this work is to contribute to the debate on the landscape preservation a little detailed thematic in view of their relevance in the current context - by indicating subsidies to the creation of a methodology for the evaluation and protection of coastal zones that may assist the government in creating new instruments, and better prepare it in control of the occupation of these areas. For such, was followed two ways to analysis: the indirect method and the direct method. The first is grounded in the evaluation of landscape attributes, which is based on the work of Raquel Tardin (2008) and Eduardo Cuesta, Encarnación Algarra and Isabel Pastor (2001). The second, based on the research of Leticia and Carlos Hardt (2010) and on the concepts of phenomenology - expressed by Antonio Christofoletti (1985) and Yi-Fu Tuan (1983) - considers the population perspective on the quality of the natural scenery. Developed through cartographic materials, photographic collections and quantitative tables, this dissertation utilized as a case study the beaches of Barra de Tabatinga and Camurupim, located in the city of Nísia Floresta/RN. Despite already being sighted spaces of advanced stage of landscape degradation in these locations, areas of remarkable scenic value can still be found, what reinforce the urgency in adopting preservationists actions. The absence of laws focused on the management and protection of the landscape singularities associated with the inefficiency of the government to invigilate the land occupation in coastal zones, encourage the excessive action of the real estate-tourism, and consequently make the government the main responsible for the environmental and landscape impacts in these areas - by its omission or by their connivance. Therefore, the legislation permeates this entire process and constitutes itself as the most effective way to guarantee the right to the landscape to present and future generations. Are also pointed some important considerations to build a methodology, especially concerning possibilities of improvements and adaptations of its applicability in each case

Natural antioxidant vitamins: A review of their beneficial roles in management of diabetes mellitus and its complications

Diabetes mellitus is a complex and progressive metabolic disease which is associated with multiple complications. Chronic hyperglycaemia is the defining characteristic of diabetes mellitus. Hyperglycaemia leads to generation of free radicals and induces oxidative stress, which has become the chief factor that leads to diabetic complications. This review supports the use of antioxidant vitamins as therapeutic agents in the management of diabetes mellitus and its complications, and also provides an insight into the potential pharmacological effects of natural antioxidant vitamins in diabetic conditions. These antioxidant vitamins can be used as safe supplements to manage the occurrence and complications of the disease. Selected studies have reported on the beneficial effects of antioxidant vitamins in experimental models. The involvement of oxidative stress in diabetes and its complications has made the use of natural antioxidant vitamins (free radical scavengers) from plants inevitable as they may be very effective and safer in the management of diabetes.

Reliability of graphite furnace atomic absorption spectrometry as alternative method for trace analysis of arsenic in natural medicinal products

Purpose: To evaluate the comparative efficiency of graphite furnace atomic absorption spectrometry (GFAAS) and hydride generation atomic absorption spectrometry (HGAAS) for trace analysis of arsenic (As) in natural herbal products (NHPs). Method: Arsenic analysis in natural herbal products and standard reference material was conducted using atomic absorption spectrometry (AAS), namely, hydride generation AAS (HGAAS) and graphite furnace (GFAAS). The samples were digested with HNO3–H2O2 in a ratio of 4:1 using microwaveassisted acid digestion. The methods were validated with the aid of the standard reference material 1515 Apple Leaves (SRM) from NIST Results: Mean recovery of three different samples of NHPs, using HGAAS and GFAAS, ranged from 89.3 - 91.4 %, and 91.7 - 93.0 %, respectively. The difference between the two methods was insignificant. A (P= 0.5), B (P=0.4) and C (P=0.88) Relative standard deviation (RSD) RSD, i.e., precision was 2.5 - 6.5 % and 2.3 - 6.7 % using HGAAS and GFAAS techniques, respectively. Recovery of arsenic in SRM was 98 and 102 % by GFAAS and HGAAS, respectively. Conclusion: GFAAS demonstrates acceptable levels of precision and accuracy. Both techniques possess comparable accuracy and repeatability. Thus, the two methods are recommended as an alternative approach for trace analysis of arsenic in natural herbal products.

Building partnership for drug and ag discovery and conservation of the natural resources in Brazil.

2009

Sistemas de medição de desempenho para projetos de PD&I no Setor de Petróleo e Gás Natural

Organizations are seeking new ideas, tools and methods aiming to improve management process and performance. On the other hand, system performance measurement needs to portray organizational changes and provide managers with a set of true and more appropriate information for the decision-making process. This work aims to propose a performance measurement system in the academic field regarding Research, Development and Innovation (RDI) in the oil and gas industry. The research performed a bibliographic review in a descriptive exploratory manner. A field research was conducted with an expert focus group in order to gather new indicators. As for the validation of these indicators, a survey with experienced professional was also realized. The research surveyed four segments in and outside of the Federal University of Rio Grande do Norte-Brazil such as oil and gas project coordinators, staff at Academic Planning Offices, FUNPEC employees as well as coordinators from Petrobrás. The performance measuring system created from this study features three interrelated performance indicators pointed out as: process indicators, outcome indicators and global indicators. The proposal includes performance indicators that seek to establish more appropriate strategies for effective institution management. It might help policy making of university-industry interaction policies

Generation and screening of natural product-like compounds for antibiotic discovery

Avec l’apparition de plus en plus de souches de bactérie résistante aux antibiotiques, le développement de nouveaux antibiotiques est devenu une important problématique pour les agences de santé. C’est pour cela que la création de nouvelles plateformes pour accélérer la découverte de médicaments est devenu un besoin urgent. Dans les dernières décennies, la recherche était principalement orientée sur la modification de molécules préexistantes, la méta-analyse d’organismes produisant des molécules activent et l’analyse de librairies moléculaires pour trouver des molécules synthétiques activent, ce qui s’est avéré relativement inefficace. Notre but était donc de développer de nouvelles molécules avec des effets thérapeutiques de façon plus efficace à une fraction du prix et du temps comparé à ce qui se fait actuellement. Comme structure de base, nous avons utilisé des métabolites secondaires qui pouvaient altérer le fonctionnement des protéines ou l’interaction entre deux protéines. Pour générer ces molécules, j’ai concentré mes efforts sur les terpènes, une classe de métabolites secondaires qui possède un large éventail d’activités biologiques incluant des activités antibactériennes. Nous avons développé un système de chromosome artificiel de levure (YAC) qui permet à la fois l’assemblage directionnel et combinatoire de gènes qui permet la création de voies de biosynthèse artificielles. Comme preuve de concept, j’ai développé des YACs qui contiennent les gènes pour l’expression des enzymes impliquées dans la biosynthèse de la -carotène et de l’albaflavenone et produit ces molécules avec un haut rendement. Finalement, Des YACs produits à partir de librairies de gènes ont permis de créer une grande diversité de molécules.

Managing Succession and Knowledge Transfer in Family Businesses: Lessons from a Comparative Research

The most natural mode of family firm succession is the intergenerational ownership transfer. Statistical evidence, however, suggests that in most cases the succession process fails. There can be several reasons as a lot of personal, emotional and structural factors can act as an inhibitor to succession. The effectiveness of the implementation of any succession strategy is strongly dependent on the efficiency of intergenerational knowledge transfer, which is related to the parties’ absorptive capacity and willingness to learn. The paper is based on the experiences learned from the INSIST project. In the framework of the project different aspects of family business succession have been investigated in three participating countries (Hungary, Poland and the United Kingdom). The aim of the paper is to identify the patterns of management, succession, knowledge transfer and learning in family businesses. Issues will be examined in detail such as the succession strategies of companies investigated and the efforts family businesses and their managers make in order to harmonize family goals (such as emotional stability, harmony, and reputation) with business- related objectives (e.g. survival, growth or profitability).

An Ethnographic Study: Becoming a Physics Expert in a Biophysics Research Group

Expertise in physics has been traditionally studied in cognitive science, where physics expertise is understood through the difference between novice and expert problem solving skills. The cognitive perspective of physics experts only create a partial model of physics expertise and does not take into account the development of physics experts in the natural context of research. This dissertation takes a social and cultural perspective of learning through apprenticeship to model the development of physics expertise of physics graduate students in a research group. I use a qualitative methodological approach of an ethnographic case study to observe and video record the common practices of graduate students in their biophysics weekly research group meetings. I recorded notes on observations and conduct interviews with all participants of the biophysics research group for a period of eight months. I apply the theoretical framework of Communities of Practice to distinguish the cultural norms of the group that cultivate physics expert practices. Results indicate that physics expertise is specific to a topic or subfield and it is established through effectively publishing research in the larger biophysics research community. The participant biophysics research group follows a learning trajectory for its students to contribute to research and learn to communicate their research in the larger biophysics community. In this learning trajectory students develop expert member competencies to learn to communicate their research and to learn the standards and trends of research in the larger research community. Findings from this dissertation expand the model of physics expertise beyond the cognitive realm and add the social and cultural nature of physics expertise development. This research also addresses ways to increase physics graduate student success towards their PhD. and decrease the 48% attrition rate of physics graduate students. Cultivating effective research experiences that give graduate students agency and autonomy beyond their research groups gives students the motivation to finish graduate school and establish their physics expertise.

Lessons from natural disasters, tsunami-affected Small and Medium-Sized Enterprises(SMEs) in Sri Lanka

The main objective of this paper is to identify some of the key issues encountered by tsunami-affected small and medium-sized enterprises (SMEs) in the process of rehabilitation and re-establishment in Sri Lanka. The second objective is to assess how far these affected industries have received various benefits and supports from bodies such as government agencies, private sector firms, donors and NGOs to help them get back into business. The final objective is to recommend policies and strategies to develop the tsunami-affected SMEs in a self-sustaining manner and within a certain time period. The main database of firms for this research has been obtained from the Industrial Development Board, which conducted a survey covering 4,389 tsunami-affected micro- and SMEs. In addition to this, information from various state organizations and NGOs-based sources has been used. This paper identifies the main issues related to tsunami-affected SMEs ranging from basic infrastructure provision up to finance, marketing, machinery, technology, training, product identification and development and so forth. In fact, it is shown that there are no significant differences between issues faced by SMEs in general and tsunami-affected SMEs, apart of course from the effects of a sudden disaster (the tidal wave). Consequently, these issues can be generalized as issues relevant to SMEs in Sri Lanka as a whole. However, under the flood and rain of local and foreign assistance, there have been more pledges and promises than actual deliveries and, so, tsunami-affected SMEs have received comparatively little support and assistance in recovering and no records can be found as to where the colossal amount of foreign assistance received has actually gone. Finally, this paper recommends various types of business incubator centres and entrepreneurial enhancing skill programmes for the revamping of tsunami-affected SMEs in addition to the normal disaster risk management plan.

Generation and screening of natural product-like compounds for antibiotic discovery

Avec l’apparition de plus en plus de souches de bactérie résistante aux antibiotiques, le développement de nouveaux antibiotiques est devenu une important problématique pour les agences de santé. C’est pour cela que la création de nouvelles plateformes pour accélérer la découverte de médicaments est devenu un besoin urgent. Dans les dernières décennies, la recherche était principalement orientée sur la modification de molécules préexistantes, la méta-analyse d’organismes produisant des molécules activent et l’analyse de librairies moléculaires pour trouver des molécules synthétiques activent, ce qui s’est avéré relativement inefficace. Notre but était donc de développer de nouvelles molécules avec des effets thérapeutiques de façon plus efficace à une fraction du prix et du temps comparé à ce qui se fait actuellement. Comme structure de base, nous avons utilisé des métabolites secondaires qui pouvaient altérer le fonctionnement des protéines ou l’interaction entre deux protéines. Pour générer ces molécules, j’ai concentré mes efforts sur les terpènes, une classe de métabolites secondaires qui possède un large éventail d’activités biologiques incluant des activités antibactériennes. Nous avons développé un système de chromosome artificiel de levure (YAC) qui permet à la fois l’assemblage directionnel et combinatoire de gènes qui permet la création de voies de biosynthèse artificielles. Comme preuve de concept, j’ai développé des YACs qui contiennent les gènes pour l’expression des enzymes impliquées dans la biosynthèse de la -carotène et de l’albaflavenone et produit ces molécules avec un haut rendement. Finalement, Des YACs produits à partir de librairies de gènes ont permis de créer une grande diversité de molécules.

Natural ventilation and indoor air quality in educational buildings: experimental assessment and improvement strategies

Indoor environmental conditions in classrooms, in particular temperature and indoor air quality, influence students’ health, attitude and performance. In recent years, several studies regarding indoor environmental quality of classrooms were published and natural ventilation proved to have great potential, particularly in southern European climate. This research aimed to evaluate indoor environmental conditions in eight schools and to assess their improvement potential by simple natural ventilation strategies. Temperature, relative humidity and carbon dioxide concentration were measured in 32 classrooms. Ventilation performance of the classrooms was characterized using two techniques, first by fan pressurization measurements of the envelope airtightness and later by tracer gas measurements of the air change rate assuming different envelope conditions. A total of 110 tracer gas measurements were made and the results validated ventilation protocols that were tested afterward. The results of the ventilation protocol implementation were encouraging and, overall, a decrease on the CO2 concentration was observed without modifying the comfort conditions. Nevertheless, additional measurements must be performed for winter conditions.

Strategic Diplomacies: Indigenous Governance, International Politics, and Natural Resources in Canada

International Relations theory would predict that central governments, with their considerable material resources, would be unlikely to face a challenge from a substate government. However, substate governments, and particularly Indigenous governments, are pushing back against central government control in both domestic and international spheres. Indigenous governments are leveraging their local mining sectors to realize their interests and express local identities—interests and identities that may not be congruent with those of the central government. Applying the case study of the resource extraction sector in Canada, this thesis asks: under what conditions are substate governments able to challenge the authority of central governments in the international arena? Canada’s reliance on the global extractive resource sector is a major driver of its international policy preferences, but the increased engagement of Indigenous governments in the sector challenges the control of the federal government. Focusing on the resource extraction sectors in British Columbia, Saskatchewan, and Ontario, this thesis argues that there is a mutually reinforcing relationship between Indigenous governments’ international engagement and their domestic autonomy; both challenge the parameters of state authority. Both force the state to respond to claims of control from multiple sites and to clarify convoluted policy environments. A confluence of factors—including increased Indigenous connections to the globalized economy, new Canadian regulatory frameworks, and recent Supreme Court of Canada cases regarding Indigenous lands—have all altered the space in which Indigenous governments in Canada participate in the resource extraction sector and produce overlapping or multilevel governance structures. This thesis demonstrates that Indigenous international engagement entrenches the authority and political legitimacy manifest in Indigenous governments’ insistence on equitable and horizontal negotiations in Canada’s lucrative resource extraction sector. A cumulative process occurs in which domestic and international expressions of political autonomy reinforce each other, produce further opportunities to express authority in both environments, and trouble the state’s capacity to fully realize its international policy preferences.