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Article
Publication date: 12 December 2016

Luis Laím and João Paulo C. Rodrigues

This paper is mainly aimed at the structural performance of compound cold-formed galvanised steel beams under fire conditions based on the results of a large programme of…

121

Abstract

Purpose

This paper is mainly aimed at the structural performance of compound cold-formed galvanised steel beams under fire conditions based on the results of a large programme of experimental tests and numerical simulations. The main objective of this research was to assess the critical temperature and time of the studied beams. Other important goals of this research work were to investigate the influence of the cross-sections (C, lipped-I, R and 2R beams) and, above all, of the axial restraint (0, 0.45, 3, 7.5, 15, 30, ∞ kN/mm) to the thermal elongation of the beam and the rotational restraint at beam supports (0, 15, 80, 150, 300, 1,200 and ∞ kN.m/rad) on the fire resistance of this kind of beams.

Design/methodology/approach

This paper still provides details of the simulation methodology for achieving numerical stability and faithful representation of detailed structural behaviour and compares the simulation and experimental results, including beam failure modes, measured beam axial forces and beam mid-span deflections.

Findings

Good agreement between Abaqus simulations and experimental observations confirms that the finite element models developed with the Abaqus/standard solver are suitable for predicting the structural fire behaviour of restrained cold-formed steel beams.

Originality/value

The results showed above all that the effect of the stiffness of the surrounding structure seems to decrease with the increasing slenderness of the beams.

Details

Journal of Structural Fire Engineering, vol. 7 no. 4
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 28 February 2019

Tiago A. de C. Pires, João Paulo C. Rodrigues and Jose J.R. Silva

Nowadays, circular concrete-filled tubular (CFT) columns are largely used in construction because of structural and architectural advantages such as high load bearing capacity and…

183

Abstract

Purpose

Nowadays, circular concrete-filled tubular (CFT) columns are largely used in construction because of structural and architectural advantages such as high load bearing capacity and aesthetic appearance. The behavior of CFT columns at ambient and high temperatures is good; however, there are problems related to their behavior in fire when inserted in a real building structure, as for example, the influence of the restraining to thermal elongation that have to be addressed in order to improve their design. This study aims to present the results of a numerical study on the behavior of CFT columns with restrained thermal elongation in case of fire.

Design/methodology/approach

The parameters tested in the numerical simulations included column slenderness, load level, surrounding structure stiffness and steel reinforcement ratio. A sequentially coupled thermal stress analysis was carried out. The numerical model was validated with results from a large series of fire resistance tests carried out at Coimbra University, in Portugal. From these, simple equations to evaluate CFT column critical times were derived.

Findings

The results were also compared with the ones obtained from the current EN 1994-1-2:2005 simplified calculation and tabulated data methods. For the analyzed cases, it was verified that, while the simplified calculation method led to safe results on the evaluation of the fire resistance of CFT columns with restrained thermal elongation, the tabulated data method led, in certain cases, to unsafe results. This research showed also lower critical times than those from literature on similar type of columns.

Originality/value

The influence of the stiffness of the surrounding structure on the behavior of CFT columns subjected to fire was not yet clear in the major part of the studies already carried out. So, this paper has the originality to consider this parameter in the numerical simulations of this type of columns.

Details

Journal of Structural Fire Engineering, vol. 10 no. 1
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 12 September 2016

Joao Paulo C. Rodrigues, Luis Laim and Hélder David Craveiro

This paper aims to present the results of a study on the behaviour of cold-formed galvanized steel beams subjected to fire, using the results of a large programme of experimental…

116

Abstract

Purpose

This paper aims to present the results of a study on the behaviour of cold-formed galvanized steel beams subjected to fire, using the results of a large programme of experimental tests.

Design/methodology/approach

The research investigated the influence of web stiffeners in the sections and the stiffness of the surrounding structure, including the axial and rotational restraining to the thermal elongation, on the flexural behaviour of the beams in case of fire. In other words, the structural response of different open cold-formed steel beams, with and without web stiffeners, was compared in case of fire.

Findings

The results showed that a good choice between using cold-formed steel beams, with and without web stiffeners, may depend on the section shape and the internal forces generated in these members during a fire.

Originality/value

Temperatures in the furnace and at several points of the beams, as well as deformations and restraining forces and moments, were measured to achieve those goals and consequently to assess the critical time and temperature of these beams.

Details

Journal of Structural Fire Engineering, vol. 7 no. 3
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 8 March 2022

Seyed Milad Komsionchi Eslamzadeh, António Grilo, Pedro Espadinha-Cruz, João Paulo C. Rodrigues and José Pedro Lopes

The purpose of this research is to review literature about the performance assessment (PA) in urban fire departments (FDs) to gain state-of-the-art of the fire departments'…

431

Abstract

Purpose

The purpose of this research is to review literature about the performance assessment (PA) in urban fire departments (FDs) to gain state-of-the-art of the fire departments' performance assessment (FDPA) and identify its most applied methods and indicators.

Design/methodology/approach

A five-stage structured literature review (SLR) is conducted to review the FDPA-related studies; then, the statistical analysis is applied to reveal more information from the extracted data and design a general framework for FDPA.

Findings

The systematic literature review resulted in 336 independent variables for FDPA and finding the data envelopment analysis (DEA) as the most applied FDPA method among the mathematical and statistical models in the reviewed papers. By using analysis outcomes, a general conceptual framework for FDPA is proposed.

Research limitations/implications

The reviewed studies were limited to assessments at the strategic level and urban fire protection services.

Practical implications

The results of this research can support fire protection service managers, decision-makers, PA researchers and academicians to have a better understanding of FDPA and state-of-the-art in this field.

Originality/value

A considerable number of studies have been done about the FDPA to provide methods to improve the efficiency and effectiveness of FDs. Although there are reviews about PA in fire service areas, to the best of our knowledge, no study has been done about FDPA.

Details

International Journal of Public Sector Management, vol. 35 no. 3
Type: Research Article
ISSN: 0951-3558

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Book part
Publication date: 23 March 2017

Barbara de Lima Voss, David Bernard Carter and Bruno Meirelles Salotti

We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in…

Abstract

We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in the construction of hegemonies in SEA research in Brazil. In particular, we examine the role of hegemony in relation to the co-option of SEA literature and sustainability in the Brazilian context by the logic of development for economic growth in emerging economies. The methodological approach adopts a post-structural perspective that reflects Laclau and Mouffe’s discourse theory. The study employs a hermeneutical, rhetorical approach to understand and classify 352 Brazilian research articles on SEA. We employ Brown and Fraser’s (2006) categorizations of SEA literature to help in our analysis: the business case, the stakeholder–accountability approach, and the critical case. We argue that the business case is prominent in Brazilian studies. Second-stage analysis suggests that the major themes under discussion include measurement, consulting, and descriptive approach. We argue that these themes illustrate the degree of influence of the hegemonic politics relevant to emerging economics, as these themes predominantly concern economic growth and a capitalist context. This paper discusses trends and practices in the Brazilian literature on SEA and argues that the focus means that SEA avoids critical debates of the role of capitalist logics in an emerging economy concerning sustainability. We urge the Brazilian academy to understand the implications of its reifying agenda and engage, counter-hegemonically, in a social and political agenda beyond the hegemonic support of a particular set of capitalist interests.

Details

Advances in Environmental Accounting & Management: Social and Environmental Accounting in Brazil
Type: Book
ISBN: 978-1-78635-376-4

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Article
Publication date: 3 January 2023

Joao Vitor da Silva Moreira, Karina Rodrigues, Daniel José Lins Leal Pinheiro, Thaís Cardoso, João Luiz Vieira, Esper Cavalheiro and Jean Faber

One of the main causes of long-term prosthetic abandonment is the lack of ownership over the prosthesis, which was caused mainly by the absence of sensory information regarding…

123

Abstract

Purpose

One of the main causes of long-term prosthetic abandonment is the lack of ownership over the prosthesis, which was caused mainly by the absence of sensory information regarding the lost limb. The period where the patient learns how to interact with a prosthetic device is critical in rehabilitation. This ideally happens within the first months after amputation, which is also a period associated with the consolidation of brain changes. Different studies have shown that the introduction of feedback mechanisms can be crucial to bypass the lack of sensorial information. To develop a biofeedback system for the rehabilitation of transfemoral amputees – controlled via electromyographic (EMG) activity from the leg muscles – that can provide real-time visual and/or vibratory feedback for the user.

Design/methodology/approach

The system uses surface EMG to control two feedback mechanisms, which are the knee joint of a prosthetic leg of a humanoid avatar in a virtual reality (VR) environment (visual feedback) and a matrix of 16 vibrotactile actuators placed in the back of the user (vibratory feedback). Data acquisition was inside a Faraday Cage using an OpenEphys® acquisition board for the surface EMG recordings. The tasks were performed on able-bodied participants, with no amputation, and for this, the dominant leg of the user was immobilized using an orthopedic boot fixed on the chair, allowing only isometric contractions of target muscles, according to the Surface EMG for Non-Invasive Assessment of Muscles (SENIAM) standard. The authors test the effectiveness of combining vibratory and visual feedback and how task difficulty affects overall performance.

Findings

The authors' results show no negative interference combining both feedback modalities and that performance peaked at the intermediate difficulty. These results provide powerful insights of what can be accomplished with the population of amputee people. By using this biofeedback system, the authors expect to engage another sensory modality in the process of spatial representation of a virtual leg, bypassing the lack of information associated with the disruption of afferent pathways following amputation.

Research limitations/implications

The authors developed a showcase with a new protocol and feedback mechanisms showing the protocol's safety, efficiency and reliability. However, since this system is designed for patients with leg amputation, the full extent of the effects of the biofeedback training can only be assessed after the evaluation with the amputees, and the results obtained so far establish a safe and operational protocol to accomplish this.

Practical implications

In this study, the authors proposed a new biofeedback device intended to be used in the preprosthetic rehabilitation phase for people with transfemoral amputation. With this new system, the authors propose a mechanism to bypass the lack of sensory information from a virtual prosthesis and help to assimilate visual and vibrotactile stimuli as a cue for movement representation.

Social implications

With this new system, the authors propose a mechanism to bypass the lack of sensory information from a virtual prosthesis and help to assimilate visual and vibrotactile stimuli as a cue for movement representation.

Originality/value

The authors' results show that all users were capable of recognizing both feedback modalities, both separate and combined, being able to respond accordingly throughout the tasks. The authors also show that for a one-session protocol, the last difficulty level imposed a greater challenge for most users, explained by the significant drop in performance disregarding the feedback modality. Lastly, the authors believe this paradigm can provide a better process for the embodiment of prosthetic devices, fulfilling the lack of sensory information for the users.

Details

Journal of Enabling Technologies, vol. 17 no. 1
Type: Research Article
ISSN: 2398-6263

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Article
Publication date: 29 December 2022

Francisca Nathalia de Sousa Leite, Eduardo Rodrigues de Castro and Henrique Ryosuke Tateishi

Constrained input use and lower productivity of rural establishments may be associated with restricted or concentrated access to financial resources, especially in developing…

254

Abstract

Purpose

Constrained input use and lower productivity of rural establishments may be associated with restricted or concentrated access to financial resources, especially in developing countries. Meanwhile, agricultural activity entails risks associated with the volatility of net cash flows and external events, which may discourage riskier but higher return investments (e.g. technology). As rural credit can alleviate the former, and rural insurance may help alleviate the latter, the combination of both policies might endorse each other. The purpose of this study is to analyze the use of rural credit and rural insurance policies with respect to productivity and crop area, in São Paulo state, Brazil, using farmer's microdata from two surveys realized in 2007/08 and 2016/17.

Design/methodology/approach

This study uses propensity score matching and the entropy balance approaches in a complementary way. This study compared three policy treatments – rural credit, rural insurance and both policies combined, against establishments that received neither one. The analysis considered sugarcane, grain and grape crops separately and employed farmer's microdata. Moreover, the analysis was stratified into two categories: establishments owned by family farmers and those that did not.

Findings

Rural credit policy is related to higher productivity and larger cultivated area for grains and only to larger area for grape crops in the last analyzed period (2016/17). Rural insurance, as a unique policy or combined with credit, is related to higher productivity and cultivated areas, for all analyzed crops, only in the second period (2016/17), as the policy became more accessible to farmers. Heterogeneity regarding crops and farmers might influence the effectiveness of these policies. Despite rural insurance being related to a better performance regarding the outcome variables, it still reaches a small share of farmers, especially when combined with credit.

Originality/value

Many studies about the effectiveness of rural credit in Brazil have been conducted throughout the years, while there have been fewer studies regarding rural insurance since it became an important policy in the mid-2000s. However, few studies have conducted an analysis comparing its individual and interactive influences, with such level of disaggregation, on a farm-level database, considering the heterogeneity of the data and the different categories of farmers.

Details

Agricultural Finance Review, vol. 83 no. 2
Type: Research Article
ISSN: 0002-1466

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Article
Publication date: 2 January 2020

João Lopes, Sergio Jesus Teixeira, João J.M. Ferreira, Paulo Silveira, Luís Farinha and João Lussuamo

The purpose of this paper is to involve the differences in the entrepreneurial intentions of student at higher education institutions (HEIs) in the Portuguese regions (mainland…

369

Abstract

Purpose

The purpose of this paper is to involve the differences in the entrepreneurial intentions of student at higher education institutions (HEIs) in the Portuguese regions (mainland and insular).

Design/methodology/approach

Applying a sample of 594 valid responses, the authors analyzed the data according to linear regression models.

Findings

The results convey how HEI students generally do not intend to become entrepreneurs in both the mainland and the insular regions. Although HEI students broadly do not aim to launch their own businesses, the results show that students in mainland regions feel they have the skills to start a business and drive it to success. In insular regions, students feel encouraged by their friends and family to set up their own business. When comparing insular and mainland regions, the results demonstrate how in insular regions, there is a greater probability that HEI students become entrepreneurs than in the mainland regions. Furthermore, entrepreneurial intentions in the mainland regions develop in terms of “opportunities” while driven by necessity in the insular regions.

Practical implications

This furthermore makes recommendations to regional governments and to HEIs in order to enable better encouragement of entrepreneurship in academia.

Originality/value

This study is original and innovative due to its comparison of the entrepreneurial intentions prevailing in mainland and insular regions and may propose new highlights to the academic scientific literature.

Details

Education + Training, vol. 62 no. 2
Type: Research Article
ISSN: 0040-0912

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Article
Publication date: 17 October 2017

Hélder Craveiro, João Paulo Correia Rodrigues and Luis Laim

The use of cold-formed steel members has increased significantly in the past few years; however, its design is only briefly addressed in the current design codes, such as the EN…

198

Abstract

Purpose

The use of cold-formed steel members has increased significantly in the past few years; however, its design is only briefly addressed in the current design codes, such as the EN 1993-1-3. To evaluate the compressive behavior of single and built-up cold-formed steel members, at ambient and simulated fire conditions with restrained thermal elongation, experimental and numerical tests were undertaken.

Design/methodology/approach

Four cross-section shapes were tested, namely, one single (lipped channel), one open built-up (I) and two closed built-up (R and 2R), considering two end support conditions, pinned and fixed. Two test set-ups were specifically developed for these tests. Based on the experimental results finite element models were developed and calibrated to allow future parametric studies.

Findings

This paper showed that increasing the level of restraint to thermal elongation and the initially applied load led to lower critical temperatures. Increasing the level of restraint to thermal elongation, the failure is governed by the generated axial restraining forces, whereas for lower levels of restraint to thermal elongation, the failure is controlled by the temperature increasing.

Originality/value

This paper is a contribution to the knowledge on the behavior of cold-formed steel columns subjected to fire, especially on the ones with a built-up cross-section, where results on thermal restrained ones are still scarce. It presented a set of experimental and numerical results useful for the development of numerical and analytical analysis concerning the development of new simplified calculation methods.

Details

Journal of Structural Fire Engineering, vol. 9 no. 3
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 1 March 2006

João Da Rocha Lima Júnior and Claudio Tavares De Alencar

The office market in São Paulo has been in recession since the year 2000. This situation came up due to two main factors: [i] the very aggressive attitude of developers during…

269

Abstract

The office market in São Paulo has been in recession since the year 2000. This situation came up due to two main factors: [i] the very aggressive attitude of developers during the period that comprises the year 1999 until 2000. At that time there was a very strong perception among investors that a new expansion era for new office buildings in São Paulo was about to begin and, moreover the Brazilian economy had started its recovery; [ii] The intense retraction of the Brazilian economy along with the political transition in 2002, which was mainly caused by the deterioration of the expectations in relation to the economic policies that would be performed by the new government.The recovery of the economic activity in the office building market firstly depends on the macroeconomic growth in Brazil and within the São Paulo metropolitan area. On the other hand, the expansion of the activity in the office buildings sector relies not only on the developers’ expectations of how and when the current vacant units will be rented, but also on the potential risk‐return composition of new buildings to be developed in the next years. This paper describes the economic scenario in which investment decisions to build new office buildings for rent in our local market are made and we also simulated both the necessary period of time for investments in the São Paulo office market to recover attractiveness and the time interval for the increase in the occupation rate absorb the actual vacant spaces. These simulations have taken place based on projections for the Brazilian GNP increase and they showed that for an annual increment of 4.5%, in 3 years could be reached both, attractiveness for new investment and occupation of vacant areas. For a 2.0% annual growth, the absorption of vacant spaces will take 4 years from now and new investment would be attractive only in 2012. Besides, we discuss the market prices fluctuations on the inflexion point where the transition from one phase of the real estate cycle (recession‐non attractiveness) to another (recovery‐attractiveness) occurs.

Details

Journal of Financial Management of Property and Construction, vol. 11 no. 1
Type: Research Article
ISSN: 1366-4387

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