904 resultados para New cutting tool


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In a study investigating the composition and spatial and temporal variation of the benthic macrofauna associated to the discharge of domestic sewage off Fortaleza, north-eastern Brazil, a new species of Syllis was found. This new species, S. guidae sp. nov., is characterized by having blades of falcigers with subdistal tooth about same length as distal tooth, but stouter than it, with spines on cutting edge almost reaching the tip of subdistal tooth, blades of falcigers with conspicuous subdistal triangular process and unusually long anal papilla between anal cirri, measuring about one-quarter of their length. Syllis guidae sp. nov., is herein described and compared with the most similar congeners.

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Direct measurements in the last decades have highlighted a new problem related to the lowering of the Coulomb barrier between the interacting nuclei due to the presence of the ""electron screening"" in the laboratory measurements. It was systematically observed that the presence of the electronic cloud around the interacting ions in measurements of nuclear reactions cross sections at astrophysical energies gives rise to an enhancement of the astrophysical S(E)-factor as lower and lower energies are explored [1]. Moreover, at present Such an effect is not well understood as the value of the potential for screening extracted from these measurements is higher than the tipper limit of theoretical predictions (adiabatic limit). On the other hand, the electron screening potential in laboratory measurement is different from that occurring in stellar plasmas thus the quantity of interest in astrophysics is the so-called ""bare nucleus cross section"". This quantity can only be extrapolated in direct measurements. These are the reasons that led to a considerable growth on interest in indirect measurement techniques and in particular the Trojan Horse Method (THM) [2,3]. Results concerning the bare nucleus cross sections measurements will be shown in several cases of astrophysical interest. In those cases the screening potential evaluated by means of the THM will be compared with the adiabatic limit and results arising from extrapolation in direct measurements.

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Information and communication technology (ICT) is a subject that is being discussed as a tool that is used within education around the world. Furthermore it can be seen as a tool for teachers to individualize students´ education. Students with literacy difficulties, such as dyslexia, are in constant need of new ways to learn, and new ways to be motivated to learn. The aim of this study is to see what research says in regard to how ICT can be used as a tool to help students with literacy difficulties. Literacy difficulties can be due to a number of things, such as the student has not been taught how to read, trouble within the family which can cause distress, or a neurological disorder such as dyslexia. Furthermore, the main research questions will focus on how ICT can be compared to traditional education forms, such as books and a more teacher centered education within the classroom, and whether ICT can be preferred. The results of this literature review indicates that ICT can be seen as a way for teachers to help students with literacy difficulties gain more self-esteem – something the literature tells us students with learning difficulties lack. The results also show how ICT can lead to a more individualized education. This is due to tools that increase reading comprehension and tools that give direct response when working with ICT, which helps students work more independently.

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A new test method based on multipass scratch testing has been developed for evaluating the mechanical and tribological properties of thin, hard coatings. The proposed test method uses a pin-on-disc tribometer and during testing a Rockwell C diamond stylus is used as the “pin” and loaded against the rotating coated sample. The influence of normal load on the number of cycles to coating damage is investigated and the resulting coating damage mechanisms are evaluated by posttest scanning electron microscopy. The present study presents the test method by evaluating the performance of Ti0.86Si0.14N, Ti0.34Al0.66N, and (Al0.7Cr0.3)2O3 coatings deposited by cathodic arc evaporation on cemented carbide inserts. The results show that the test method is quick, simple, and reproducible and can preferably be used to obtain relevant data concerning the fatigue, wear, chipping, and spalling characteristics of different coating-substrate composites. The test method can be used as a virtually nondestructive test and, for example, be used to evaluate the fatigue and wear resistance as well as the cohesive and adhesive interfacial strength of coated cemented carbide inserts prior to cutting tests.

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Information and communications technology (ICT) is a broad concept, which is often discussed in relation to the development of education. More specially, ICT can be seen as a tool to help teachers individualize students’ education. Students who have literacy difficulties, such as dyslexia, are in constant need of new techniques to help them learn and new tools to make their educational development easier. The aim of this thesis is to show what views teachers have regarding using ICT in English teaching at a sample of schools in the south of Sweden. A secondary part of the aim is to see what ICT tools, or other non ICT related methods, these teachers use to improve literacy skills for students with dyslexia.This empirical study is based on interviews with six participants. Previous research within the area is presented and different aspects of ICT within the National Agency for Education in Sweden, and the English syllabus, are also discussed. The results of this thesis show that ICT is seen as a helpful tool to make education easier for both students and teachers. Tools such as ViTal, Spell Right and Legimus are being used and the participants of the study also use iPads and Chromebooks in their teaching. According to the interviews, ICT can tribute to a fun way of learning and a more individualized education. Other non ICT related methods are also used to help students with dyslexia and these are often in terms of pictures in connection to words. These findings are based on a limited number of participants in a small area of south of Sweden. Therefore, further research is needed to see if the findings can be verified with more participants, in different parts of the country.

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O conceito de responsabilidade social corporativa (RSE) evoluiu gradualmente do objetivo de satisfazer as expectativas dos acionistas para o cumprimento das expectativas das partes interessadas. Tornou-se um conceito amplamente aceitado e promovido como as empresas enfrentam maiores pressões de atores internos e externos para cumprir objetivos sociais maiores. Assim, elas cada vez mais comunicam sobre os esforços de responsabilidade social delas, a fim de fomentar a confiança e o envolvimento dos stakeholders. Mas o aumento da cidadania global e as novas tecnologias de informação e de comunicação – como as mídias sociaias – está criando uma paisagem desafiador para a comunicação RSE, se traduzindo em escrutínio e ceticismo do público. No entanto, também está criando novas oportunidades para as empresas compartilhar e interagir com as partes interessadas. O estudo analisa especificamente como os blogs corporativos dedicados à comunicação RSE conseguem melhorar as relações entre as empresas e as partes interessadas. Esta pesquisa exploratória da estrutura e das mensagens de 9 blogs corporativos, é baseada em um quadro de análise sobre comunicação RSE em plataformas de mídias sociais desenvolvido por Gomez e Chalmeta (2013). O quadro está melhorado e adaptado para blogs graças à literatura sobre comunicação RSE, mídias sociais e blogs corporativos. Os resultados demonstram que o uso de características de blogs como apresentação, conteúdo e interatividade, é diversificado e reflete estratégias diferentes de comunicação RSE. Blogs permitem às empresas aumentar a visibilidade da comunicação RSE, melhorar a credibilidade e a legitimidade dos esforços de responsabilidade social, e também trazer discussões com os stakeholders. No entanto, demonstramos que as características e recursos dos blogs raramente são totalmente desenvolvidos, sugerindo avenidas para a melhoria no campo da comunicação nas mídias sociais. Especificamente, o uso da interatividade para criar relações baseadas em diálogo entre empresas e stakeholders está até atrasado em relação à extensão das oportunidades oferecidas pelos blogs. Além disso, o grau de utilização das ferramentas de blogs determina a eficácia da comunicação de RSE 2.0 das empresas na criação de relações empresa-stakeholder.

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The Brazilian start-up Local Wander plans to enter the tourism sector with a mobile application aiming to enable a new form of travel research. A web-based survey has been sent out to the start-up’s target audience (n: 236) in order to gain further relevant information for the designing of Local Wander’s market entry strategy. By applying the diffusion of innovation theory, this thesis could detect five different adopter categories, originally described by Rogers (1962), among Local Wander’s target audience based on their adoption intention. The Early Market was observed to be significantly bigger than the theory predicted. Research revealed four characteristics to be of significant impact on the adoption intention: Relative Perceived Product Advantage, Perceived Product Complexity, Compatibility with digital travel research sources, and the adopter’s Innovativeness towards mobile applications. Specific characteristics in order to identify Local Wander’s early users, the so called Innovators, were detected giving indications for further necessary company market research. Findings showed that the diffusion of innovation framework is a helpful tool for start-ups’ prospective decision making and market entry strategy planning.

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This paper reports on the development and optimization of a modified Quick, Easy, Cheap Effective, Rugged and Safe (QuEChERS) based extraction technique coupled with a clean-up dispersive-solid phase extraction (dSPE) as a new, reliable and powerful strategy to enhance the extraction efficiency of free low molecular-weight polyphenols in selected species of dietary vegetables. The process involves two simple steps. First, the homogenized samples are extracted and partitioned using an organic solvent and salt solution. Then, the supernatant is further extracted and cleaned using a dSPE technique. Final clear extracts of vegetables were concentrated under vacuum to near dryness and taken up into initial mobile phase (0.1% formic acid and 20% methanol). The separation and quantification of free low molecular weight polyphenols from the vegetable extracts was achieved by ultrahigh pressure liquid chromatography (UHPLC) equipped with a phodiode array (PDA) detection system and a Trifunctional High Strength Silica capillary analytical column (HSS T3), specially designed for polar compounds. The performance of the method was assessed by studying the selectivity, linear dynamic range, the limit of detection (LOD) and limit of quantification (LOQ), precision, trueness, and matrix effects. The validation parameters of the method showed satisfactory figures of merit. Good linearity (View the MathML sourceRvalues2>0.954; (+)-catechin in carrot samples) was achieved at the studied concentration range. Reproducibility was better than 3%. Consistent recoveries of polyphenols ranging from 78.4 to 99.9% were observed when all target vegetable samples were spiked at two concentration levels, with relative standard deviations (RSDs, n = 5) lower than 2.9%. The LODs and the LOQs ranged from 0.005 μg mL−1 (trans-resveratrol, carrot) to 0.62 μg mL−1 (syringic acid, garlic) and from 0.016 μg mL−1 (trans-resveratrol, carrot) to 0.87 μg mL−1 ((+)-catechin, carrot) depending on the compound. The method was applied for studying the occurrence of free low molecular weight polyphenols in eight selected dietary vegetables (broccoli, tomato, carrot, garlic, onion, red pepper, green pepper and beetroot), providing a valuable and promising tool for food quality evaluation.

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Crude extracts of new and old sesame leaves (Sesamum indicum, Linaeus) obtained by a sequential process of extraction were tested through contact experiments to investigate their toxicity to Atta sexdens rubropilosa (Forel) workers. Methanol extract of old leaves was toxic to leaf-cutting ants at the lower tested concentration (20mg.ml(-1)). This extract was fractioned and their fractions were tested showing a toxic effect of the methanol fraction. The methanol fraction was fractioned again and the sub fraction responsible for worker's toxicity is composed of some sugars.

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The progresses of the Internet and telecommunications have been changing the concepts of Information Technology IT, especially with regard to outsourcing services, where organizations seek cost-cutting and a better focus on the business. Along with the development of that outsourcing, a new model named Cloud Computing (CC) evolved. It proposes to migrate to the Internet both data processing and information storing. Among the key points of Cloud Computing are included cost-cutting, benefits, risks and the IT paradigms changes. Nonetheless, the adoption of that model brings forth some difficulties to decision-making, by IT managers, mainly with regard to which solutions may go to the cloud, and which service providers are more appropriate to the Organization s reality. The research has as its overall aim to apply the AHP Method (Analytic Hierarchic Process) to decision-making in Cloud Computing. There to, the utilized methodology was the exploratory kind and a study of case applied to a nationwide organization (Federation of Industries of RN). The data collection was performed through two structured questionnaires answered electronically by IT technicians, and the company s Board of Directors. The analysis of the data was carried out in a qualitative and comparative way, and we utilized the software to AHP method called Web-Hipre. The results we obtained found the importance of applying the AHP method in decision-making towards the adoption of Cloud Computing, mainly because on the occasion the research was carried out the studied company already showed interest and necessity in adopting CC, considering the internal problems with infrastructure and availability of information that the company faces nowadays. The organization sought to adopt CC, however, it had doubt regarding the cloud model and which service provider would better meet their real necessities. The application of the AHP, then, worked as a guiding tool to the choice of the best alternative, which points out the Hybrid Cloud as the ideal choice to start off in Cloud Computing. Considering the following aspects: the layer of Infrastructure as a Service IaaS (Processing and Storage) must stay partly on the Public Cloud and partly in the Private Cloud; the layer of Platform as a Service PaaS (Software Developing and Testing) had preference for the Private Cloud, and the layer of Software as a Service - SaaS (Emails/Applications) divided into emails to the Public Cloud and applications to the Private Cloud. The research also identified the important factors to hiring a Cloud Computing provider

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Leucoagaricus gongylophorus, the fungus cultured by the leaf-cutting ant Atta sexdens, produces polysaccharidases that degrade leaf components by generating nutrients believed to be essential for ant nutrition. We evaluated pectinase, amylase, xylanase, and cellulase production by L. gongylophorus in laboratory cultures and found that polysaccharidases are produced during fungal growth on pectin, starch, cellulose, xylan, or glucose but not cellulase, whose production is inhibited during fungal growth on xylan. Pectin was the carbon source that best stimulated the production of enzymes, which showed that pectinase had the highest production activity of all of the carbon sources tested, indicating that the presence of pectin and the production of pectinase are key features for symbiotic nutrition on plant material. During growth on starch and cellulose, polysaccharidase production level was intermediate, although during growth on xylan and glucose, enzyme production was very low. We propose a possible profile of polysaccharide degradation inside the nest, where the fungus is cultured on the foliar substrate.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In machining of internal threads, dedicated tools, known as taps, are needed for each profile type, diameter, and low cutting speed values are used when compared to main machining processes. This restriction in the cutting speed is associated with the difficulty of synchronizing the tool s rotation speed and feed velocity in the process. This fact restricts the flexibility and makes machining lead times longer when manufacturing of components with threads is required. An alternative to the constraints imposed by the tap is the thread milling with helical interpolation technique. The technique is the fusion of two movements: rotation and helical interpolation. The tools may have different configurations: a single edge or multiple edges (axial, radial or both). However, thread milling with helical interpolation technique is relatively new and there are limited studies on the subject, a fact which promotes challenges to its wide application in the manufacturing shop floor. The objective of this research is determine the performance of different types of tools in the thread milling with helical interpolation technique using hardened steel workpieces. In this sense, four tool configurations were used for threading milling in AISI 4340 quenched and tempered steel (40 HRC). The results showed that climb cut promoted a greater number of machined threads, regardless of tool configuration. The upcut milling causes chippings in cutting edge, while the climb cutting promotes abrasive wear. Another important point is that increase in hole diameter by tool diameter ratio increases tool lifetime