Evaluation of mechanical, physical and thermal performance of cement-based tiles reinforced with vegetable fibers

The objective of this work was to analyze mechanical, physical and thermal performance of roofing tiles produced with several formulations of cement-based matrices reinforced with sisal and eucalyptus fibers. The physical properties of the tiles were more influenced by the fiber content of the composite than by the type of reinforcement. The type of the fiber was the main variable for the achievement of the best results of mechanical properties. Exposure to tropical climate has caused a severe reduction in the mechanical properties of the composites. After approximately four months of age under external weathering the toughness of the vegetable fiber-cement fell to 53-68% of the initial toughness at 28 days of age. The thermal performance showed that roofing tiles reinforced with vegetable fiber are acceptable as substitutes of asbestos-cement sheets. (c) 2006 Elsevier Ltd. All rights reserved.

Comparing detection and location performance of perpendicular and parallel broadside GPR antenna orientations

GPR (Ground Penetrating Radar) results are shown for perpendicular broadside and parallel broadside antenna orientations. Performance in detection and localization of concrete tubes and steel tanks is compared as a function of acquisition configuration. The comparison is done using 100 MHz and 200 MHz center frequency antennas. All tubes and tanks are buried at the geophysical test site of IAG/USP in Sao Paulo city, Brazil. The results show that the long steel pipe with a 38-mm diameter was well detected with the perpendicular broadside configuration. The concrete tubes were better detected with the parallel broadside configuration, clearly showing hyperbolic diffraction events from all targets up to 2-m depth. Steel tanks were detected with the two configurations. However, the parallel broadside configuration was generated to a much lesser extent an apparent hyperbolic reflection corresponding to constructive interference of diffraction hyperbolas of adjacent targets placed at the same depth. Vertical concrete tubes and steel tanks were better contained with parallel broadside antennas, where the apexes of the diffraction hyperbolas better corresponded to the horizontal location of the buried target disposition. The two configurations provide details about buried targets emphasizing how GPR multi-component configurations have the potential to improve the subsurface image quality as well as to discriminate different buried targets. It is judged that they hold some applicability in geotechnical and geoscientific studies. (C) 2009 Elsevier B.V. All rights reserved.

Biomechanical effects of environmental and engineered particles on human airway smooth muscle cells

The past decade has seen significant increases in combustion-generated ambient particles, which contain a nanosized fraction (less than 100 nm), and even greater increases have occurred in engineered nanoparticles (NPs) propelled by the booming nanotechnology industry. Although inhalation of these particulates has become a public health concern, human health effects and mechanisms of action for NPs are not well understood. Focusing on the human airway smooth muscle cell, here we show that the cellular mechanical function is altered by particulate exposure in a manner that is dependent upon particle material, size and dose. We used Alamar Blue assay to measure cell viability and optical magnetic twisting cytometry to measure cell stiffness and agonist-induced contractility. The eight particle species fell into four categories, based on their respective effect on cell viability and on mechanical function. Cell viability was impaired and cell contractility was decreased by (i) zinc oxide (40-100 nm and less than 44 mu m) and copper(II) oxide (less than 50 nm); cell contractility was decreased by (ii) fluorescent polystyrene spheres (40 nm), increased by (iii) welding fumes and unchanged by (iv) diesel exhaust particles, titanium dioxide (25 nm) and copper(II) oxide (less than 5 mu m), although in none of these cases was cell viability impaired. Treatment with hydrogen peroxide up to 500 mu M did not alter viability or cell mechanics, suggesting that the particle effects are unlikely to be mediated by particle-generated reactive oxygen species. Our results highlight the susceptibility of cellular mechanical function to particulate exposures and suggest that direct exposure of the airway smooth muscle cells to particulates may initiate or aggravate respiratory diseases.

Heat losses and thermal performance of commercial combined solar and pellet heating systems

Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 two with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The lower efficiency of pellet heaters compared to oil or gas heaters increases the primary energy demand. Consequently heat losses of the various systems have been studied. The systems have been modeled in TRNSYS and simulated with parameters identified from measurements. For almost all systems the flue gas losses are the main heat losses except for system 3 where store heat losses prevail. Relevant are also the heat losses of the burner and the boiler to the ambient. Significant leakage losses are noticed for system 3 and 4. For buildings with an open internal design system 1 is the most efficient solution. Other buildings should preferably apply system 3. The right choice of the system depends also on whether the heater is placed inside or outside of the heated are. A large potential for system optimization exist for all studied systems, which when applied could alter the relative merits of the different system types.

Salesperson’s Personality, Motivation and Selling Performance : The Study of New Product Selling

In the highly competitive environment businesses invest big amounts of money into the new product development. New product success potentially depends on different factors among which salespeople play an important role. The aim of this paper is to explore the potential link between salespeople’s personality, motivation to sell new products and performance in selling new products. Based on the theoretical background of the Big Five personality dimensions, motivation and selling performance hypotheses were formulated and tested using statistical methods of correlation and regression analysis. The data was collected within one technologically intensive organization – ABB AB in Sweden using online web questionnaire and self-assessment measurements. Total investigation was conducted among organization’s salesforce. The findings confirm the importance of salesperson’s personality empirically showing that the latter significantly predicts both motivation and performance in selling new products. From all the Big Five Extraversion was confirmed to be the most important predictor of both motivation and performance in selling new products. Extraversion was found positively related with both motivation and performance in selling new products. Salespeople scoring high in Extraversion and especially possessing such characteristics as confident, energetic and sociable tend to be more motivated to sell new products and show higher performance results. Other personality dimensions such as Agreeableness, Conscientiousness, Neuroticism, and Openness to experience complexly approached are not proved to be significantly related neither with motivation nor performance in selling new products. The results are explained by the extreme importance of Extraversion in new product selling situation which analyzing in combination with the other personality dimensions suppresses the others. Finding regarding controlling for certain demographical characteristics of salespeople reveal that performance in selling new products is determined by selling experience. Salespeople’s age is not proved to be significantly related neither with motivation nor performance in selling new products. Findings regarding salespeople’s gender though proposing that males are more motivated to sell new products cannot be generalized due to the study limitations.

Final report on heat pump developments in WP 4 - MacSheep Deliverable 4.4 : MacSheep -New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance

FP7- MacSheep

A user guide to simple monitoring and sustainable operation of PV-diesel hybrid systems : Handbook for system users and operators

This report contains a suggestion for a simple monitoring and evaluation guideline for PV-diesel hybrid systems. It offers system users a way to better understand if their system is operated in a way that will make it last for a long time. It also gives suggestions on how to act if there are signs of unfavourable use or failure. The application of the guide requires little technical equipment, but daily manual measurements. For the most part, it can be managed by pen and paper, by people with no earlier experience of power systems.The guide is structured and expressed in a way that targets PV-diesel hybrid system users with no, or limited, earlier experience of power engineering. It is less detailed in terms of motivations for certain choices and limitations, but rich in details concerning calculations, evaluation procedures and maintenance routines. A more scientific description of the guide can be found in a related journal article.

Decentralization and education performance: a first view to the Brazilian process

This paper analyses the impact of the decentralization in educational system that is taking place in Brazil in the last decade, as a result of several laws that encourage municipalities to invest in fundamental education. The proficiency tests undertaken by the government allows to follow some public schools in two points in time. Therefore we were able to create an experimental group with the schools that were under state system in the SAEB exam and have migrated to the municipality system by the time of Prova Brasil and a control group with the schools that were under the state system between the two exams and compare the difference in their results using a fixed effect panel data analysis. The difference in difference estimator indicates that there is no significant change in the performance of the students.

Sustentabilidade e equilíbrio do crescimento: uma abordagem contábil-financeira

Este trabalho transita por duas áreas de conhecimento, gestão contábil-financeira e sustentabilidade, que precisam se aproximar na troca de conceitos e práticas para que se viabilize a contribuição das empresas para o desenvolvimento sustentável. O propósito do estudo é verificar se o crescimento equilibrado está associado ao desempenho sustentável das empresas. Partindo do pressuposto que o crescimento desequilibrado é um fator de risco para a empresa e para todos os que se relacionam com ela (stakeholders), podendo gerar impactos econômico-financeiros, sociais e ambientais, é de se esperar que as empresas sustentáveis apresentem um crescimento mais equilibrado, medido pelo indicador equilíbrio do crescimento, que reflete se há preocupação com a pressão sobre o uso de todos os tipos de recursos e a sua forma de financiamento. O desempenho sustentável das empresas deve ser avaliado de forma ampla, com base no conceito do Triple Bottom Line, buscando atender às necessidades de vários stakeholders; neste trabalho o desempenho sustentável será operacionalizado de duas maneiras: pela adesão aos segmentos diferenciados de governança corporativa da Bovespa e pela participação na carteira do Índice de Sustentabilidade Empresarial da Bovespa (ISE-Bovespa). Os objetivos do trabalho são: verificar se as empresas consideradas sustentáveis, pelos critérios separados e depois em conjunto, apresentam menor variabilidade no indicador equilíbrio do crescimento do que as empresas não consideradas sustentáveis pelos mesmos critérios; verificar se as empresas apresentam menor variabilidade no indicador equilíbrio do crescimento no segundo período da análise do que no primeiro, períodos estes separados pela divulgação da primeira carteira do ISE-Bovespa, em 2005. Foram utilizados dados de empresas de capital aberto no período de dezembro de 1999 a dezembro de 2009; as empresas foram divididas em grupos e o estudo se concentrou na variabilidade do equilíbrio do crescimento nos grupos, medida pelo desvio padrão, considerando-se que todos os grupos apresentam médias próximas da unidade. Um grupo com baixa variabilidade no equilíbrio do crescimento mostra uma maior preocupação com o uso de recursos de forma equilibrada, refletindo uma postura compatível com a contribuição das empresas para o desenvolvimento sustentável. A confirmação de dez em doze hipóteses de pesquisa permite interpretar que, no conjunto, o resultado é fortemente aderente à hipótese de associação entre o crescimento equilibrado e o desempenho sustentável

Test score disclosure and school performance

In this paper we test whether the disclosure of test scores has direct impacts on student performance, school composition and school inputs. We take advantage of the discontinuity on the disclosure rules of The National Secondary Education Examination (ENEM) run in Brazil by the Ministry of Education: In 2006 it was established that the 2005 mean score results would be disclosed for schools with ten or more students who took the exam in the previous year. We use a regression discontinuity design to estimate the e ects of test disclosure. Our results indicate that private schools that had their average scores released in 2005 outperformed those that did not by 0.2-0.6 in 2007. We did not nd same results for public schools. Moreover, we did not nd evidence that treated schools adjusted their inputs or that there was major changes in the students composition of treated schools. These ndings allow us to interpret that the main mechanism driving the di erences in performance was the increased levels of students', teachers' and principals' e ort exerted by those in schools that had scores publicized.

Are defaults a family affair?: the relationship between kinship and microloan performance

A partir de uma grande base de dados fornecida por uma instituição de microcrédito do nordeste brasileiro, a relação entre parentesco e inadimplência é analisada. O presente trabalho mostra evidências de que o parentesco entre membros de um grupo solidário afeta positivamente a adimplência. Grupos em que todos os membros possuíam algum laço de parentesco entre si apresentaram uma probabilidade 24% menor de inadimplência do que grupo sem esses laços. Além disso, quando considerado apenas o primeiro empréstimo, grupos com 100% de parentesco entre os membros apresentaram uma probabilidade 45% menor de inadimplência em comparação com membros sem relações de parentesco. Os resultados deste trabalho também mostram que há uma relação negativa entre parentesco e probabilidade de mudança na formação de um grupo solidário. Essas análises permitem fazer inferências acerca dos mecanismos pelos quais o parentesco afeta o desempenho do microcrédito. Os resultados sugerem que o parentesco possui um benefício maior no processo de autosseleção do grupo. Além disso, os resultados também sugerem que o impacto positivo do parentesco nas atividades de automonitoramento compensa o enfraquecimento das atividades de enforcement.

The relationship between board of director's nationality diversity and financial performance

Companies are moving to a more international structure; going into new markets and having an increased competition in all fronts. Therefore, the practices that lead companies to a more efficient and competitive position are praised. The management of the workforce comes as one of the main concerns of companies, aiming at performance enhancing and at creating better environments that both attract and maintain the professional talents. In an increasingly international environment, companies tend to look for the specialists and best professionals, regardless of their nationality. This new structure with several different nationalities working together poses new challenges for companies. Understanding if and how a more diverse has a relationship with financial performance is the starting point for better managing this new corporate structure.

Demand and supply: price elasticities and corporate performance in the UK

This paper investigates the relationship between consumer demand and corporate performance in several consumer industries in the UK, using two independent datasets. It uses data on consumer expenditures and the retail price index to estimate Almost Ideal Demand Systems on micro-data and compute timevarying price elasticities of demand for disaggregated commodity groups. Then, it matches the product definitions to the Standard Industry Classification and uses the estimated elasticities to investigate the impact of consumer behaviour on firm-level profitability equations. The time-varying household characteristics are ideal instruments for the demand effects in the firms' supply equation. The paper concludes that demand elasticities have a significant and tangible impact on the profitability of UK firms and that this impact can shed some light on the relationship between market structure and economic performance.

Effects of capital structure on markups and competitive performance : evidence from Portugal

Este estudo avalia os efeitos da estrutura de capital nas margens de lucro e no desempenho competitivo. Aplica teorias relativas à contra ciclicidade das margens de lucro, e aos resultados do mercado do produto de Chevalier e Scharfstein (1996), a dados portugueses, seguindo a metodologia de Campello (2001). Utilizando dados de painel de empresas pertencentes à indústria transformadora Portuguesa, a análise fornece evidencia para a contra-ciclicidade de margens de lucro e de um efeito conjunto de dívida e recessão económica nas margens de lucro. Tendo por base o recenseamento de empresas Portuguesas, a análise não fornece evidência de uma relação significativa entre a estrutura de capital e o desempenho competitivo.