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1 – 10 of 40Hesam Ketabdari, Amir Saedi Daryan, Nemat Hassani and Mohammad Safi
In this paper, the seismic behavior of the gusset plate moment connection (GPMC) exposed to the post-earthquake fire (PEF) is investigated.
Abstract
Purpose
In this paper, the seismic behavior of the gusset plate moment connection (GPMC) exposed to the post-earthquake fire (PEF) is investigated.
Design/methodology/approach
For this purpose, for the sake of verification, first, a numerical model is built using ABAQUS software and then exposed to earthquakes and high temperatures. Afterward, the effects of a series of parameters, such as gusset plate thickness, gap width, steel grade, vertical load value and presence of the stiffeners, are evaluated on the behavior of the connection in the PEF conditions.
Findings
Based on the results obtained from the parametric study, all parameters effectively played a role against the seismic loads, although, when exposed to fire, it was found that the vertical load value and presence of the stiffener revealed a great contribution and the other parameters could not significantly affect the connection performance. Finally, to develop the modeling and further study the performance of the connection, the 4 and 8-story frames are subjected to 11 accelerograms and 3 different fire scenarios. The findings demonstrate that high temperatures impose rotations on the structure, such that the story drifts were changed compared to the post-earthquake drift values.
Originality/value
The obtained results can be used by engineers to design the GPMC for the combined action of earthquake and fire.
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The conflict between institutionalism and neoclassicism in the 20th century has been investigated by scholars over the years. Many of them believe that in the postwar period…
Abstract
The conflict between institutionalism and neoclassicism in the 20th century has been investigated by scholars over the years. Many of them believe that in the postwar period, neoclassicism triumphed while institutionalism largely disappeared. The present chapter takes a very different view. The late 20th century represents a broad synthesis of neoclassical and institutional themes in a methodology we call pragmatic empiricism. That approach combines the mathematical model building and theoretical formalism of neoclassical economics with the institutional economist’s data-driven statistical analysis and concern for developing institutional forms. We use as a case study the history of American locational economics from the 1930s to the present. The mixing of institutional and neoclassical themes is quite evident in the work of three young scholars at Harvard who effectively initiated American locational economics. In the postwar period, we find a series of outstanding, well-published papers that capture the spirit of the “founders.” These papers do use more modeling, but they also focus on major institutional developments. A broader review of locational works is consistent with the pragmatic empiricism label. The history of locational economics supports the claim that institutionalism, far from disappearing, continues to provide fundamental questions and techniques for modern pragmatic empiricism.
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Abbas Rezaeian, Mona Mansoori and Amin Khajehdezfuly
Top-seat angle connection is known as one of the usual uncomplicated beam-to-column joints used in steel structures. This article investigates the fire performance of welded…
Abstract
Purpose
Top-seat angle connection is known as one of the usual uncomplicated beam-to-column joints used in steel structures. This article investigates the fire performance of welded top-seat angle connections.
Design/methodology/approach
A finite element (FE) model, including nonlinear contact interactions, high-temperature properties of steel, and material and geometric nonlinearities was created for accomplishing the fire performance analysis. The FE model was verified by comparing its simulation results with test data. Using the verified model, 24 steel-framed top-seat angle connection assemblies are modeled. Parametric studies were performed employing the verified FE model to study the influence of critical factors on the performance of steel beams and their welded angle joints.
Findings
The results obtained from the parametric studies illustrate that decreasing the gap size and the top angle size and increasing the top angles thickness affect fire behavior of top-seat angle joints and decrease the beam deflection by about 16% at temperatures beyond 570 °C. Also, the fire-resistance rating of the beam with seat angle stiffener increases about 15%, compared to those with and without the web stiffener. The failure of the beam happens when the deflections become more than span/30 at temperatures beyond 576 °C. Results also show that load type, load ratio and axial stiffness levels significantly control the fire performance of the beam with top-seat angle connections in semi-rigid steel frames.
Originality/value
Development of design methodologies for these joints and connected beam in fire conditions is delayed by current building codes due to the lack of adequate understanding of fire behavior of steel beams with welded top-seat angle connections.
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Kryzelle M. Atienza, Apollo E. Malabanan, Ariel Miguel M. Aragoncillo, Carmina B. Borja, Marish S. Madlangbayan and Emel Ken D. Benito
Existing deterministic models that predict the capacity of corroded reinforced concrete (RC) beams have limited applicability because they were based on accelerated tests that…
Abstract
Purpose
Existing deterministic models that predict the capacity of corroded reinforced concrete (RC) beams have limited applicability because they were based on accelerated tests that induce general corrosion. This research gap was addressed by performing a combined numerical and statistical analysis on RC beams, subjected to natural corrosion, to achieve a much better forecast.
Design/methodology/approach
Data of 42 naturally corroded beams were collected from the literature and analyzed numerically. Four constitutive models and their combinations were considered: the elastic-semi-plastic and elastic-perfectly-plastic models for steel, and two tensile models for concrete with and without the post-cracking stresses. Meanwhile, Popovics’ model was used to describe the behavior of concrete under compression. Corrosion coefficients were developed as functions of corrosion degree and beam parameters through linear regression analysis to fit the theoretical moment capacities with test data. The performance of the coefficients derived from different combinations of constitutive laws was then compared and validated.
Findings
The results showed that the highest accuracy (R2 = 0.90) was achieved when the tensile response of concrete was modeled without the residual stresses after cracking and the steel was analyzed as an elastic-perfectly-plastic material. The proposed procedure and regression model also showed reasonable agreement with experimental data, even performing better than the current models derived from accelerated tests and traditional procedures.
Originality/value
This study presents a simple but reliable approach for quantifying the capacity of RC beams under more realistic conditions than previously reported. This method is simple and requires only a few variables to be employed. Civil engineers can use it to obtain a quick and rough estimate of the structural condition of corroding RC beams.
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In 2017, it was a challenge to assess the future of global trade. It was an open question whether the US financial crisis and the recession that it triggered would mark a turning…
Abstract
In 2017, it was a challenge to assess the future of global trade. It was an open question whether the US financial crisis and the recession that it triggered would mark a turning point for the liberal post–World War II world order. If one looked toward Europe, China, Latin America, and Japan, there was a flurry of activity. New trade agreements were being completed and pursued. In Washington, DC, on the other hand, President Donald Trump seemed set on ripping apart and/or renegotiating any trade deal the United States was ever part of.
This case explores Trump's opinions and emerging policy stance on trade, bilateralism, and the global economy, among others. It also gives an overview of the World Trade Organization (WTO) and the General Agreement on Tariffs and Trade (GATT) and asks whether the Trump presidency would constitute a major challenge to the WTO and what it stood for in 2017.
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This study aims to explore the evolutionary trajectory of American corporations and their governance over the past few centuries, using a multidisciplinary investigative approach…
Abstract
Purpose
This study aims to explore the evolutionary trajectory of American corporations and their governance over the past few centuries, using a multidisciplinary investigative approach. The research focuses on the American business landscape because it has played a pivotal role in shaping the field of corporate governance theory and practice.
Design/methodology/approach
The author thoroughly investigates archival records, legal documents, academic publications, reputable databases and pertinent literature to unearth valuable insights into the key events that have influenced the evolutionary path of American corporations and their governance throughout history.
Findings
Delving into the evolutionary journey of American corporations and their governance reveals a multifaceted narrative, enhancing our comprehension of the impact of the external socio-economic environment, and the effectiveness and limitations of established corporate governance paradigms in addressing such transformations. This introspection establishes the groundwork for ongoing discussions concerning how corporate governance should adapt to meet the evolving needs and expectations of stakeholders and society as a whole, with a specific focus on the pivotal role that boardrooms could play in this regard.
Practical implications
The insights gained from this analysis offer practitioners a foundational resource to understand corporate governance in a complex business landscape. Armed with this understanding, practitioners can better align governance strategies with both historical context and contemporary requirements.
Social implications
The research has significant social implications in the sense that history highlights the importance of the society in influencing corporate governance practices. It specifically emphasizes the need for the board of directors to consider both shareholder value and social responsibility, while also fostering public trust and confidence.
Originality/value
Many corporate governance concepts are often used with limited understanding of their initial intent, resulting in their unquestioned adoption. In this paper, the author offers a contextual exploration of historical events that have contributed to the development of these diverse corporate perspectives. To the best of the author’s knowledge, there are exceedingly few, if any, papers that present comparably insightful and multidisciplinary insights into the evolutionary path of corporations and their governance, especially within a dynamic and influential market like that of the USA.
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Domingo de-Pedro-Jiménez, Esther Foncubierta-Sierra, Esther Domínguez-Romero, Juan Vega-Escaño, Marta Hernández Martín and Cristina Gavira Fernández
This paper aims to study the influence of leisure-time physical activity on depression crises and the difficulty in performing light household tasks.
Abstract
Purpose
This paper aims to study the influence of leisure-time physical activity on depression crises and the difficulty in performing light household tasks.
Design/methodology/approach
A population-based cross-sectional study was conducted using data from the 2020 European Health Survey in Spain. A total of 1,076 individuals diagnosed with depression were selected. ANOVA, chi-square, Fisher’s exact test and Mann–Whitney U test were applied, and a simple moderation analysis was conducted using the SPSS PROCESS 4.0 macro.
Findings
Women had higher percentages of some or much difficulty in performing domestic activities (p = 0.007). Differences were found between experiencing a crisis in the past 12 months versus not having one (p < 0.001): less physical activity was performed, perceived health was worse and difficulty in performing domestic activities increased. The moderation analysis confirmed the moderating effect of physical activity on the relationship between experiencing a crisis and having difficulty with domestic activities (p = 0.017).
Research limitations/implications
The usual limitation of descriptive cross-sectional studies, which cannot establish causal relationships, must be added to low sample sizes in some categories.
Practical implications
The analysis with gender differentiation, promoting gender-specific adapted practices, considering age and personal circumstances of the patient, appropriate exercise prescription, as well as its evaluation and follow-up, are areas where specialist nurses need to delve deeper to enhance the quality of care.
Originality/value
Leisure-time physical activity moderates the relationship between experiencing a crisis and having difficulty with light household tasks: those who engage in occasional physical activity have less difficulty compared to those who do not engage in it.
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Vaishali Choubey, Serlene Tomar, Surbhi Yadav, Bhavana Gupta, Ankur Khare, Pradeep Kumar Singh and Somesh Kumar Meshram
The purpose of the study was to produce a healthier, convenient and traditional ready-to-eat (RTE) snack option with increased nutritional value, using spent hen meat, dietary…
Abstract
Purpose
The purpose of the study was to produce a healthier, convenient and traditional ready-to-eat (RTE) snack option with increased nutritional value, using spent hen meat, dietary fibre (DF) and simple technological methods. The product was designed to be stable without refrigeration and be easily adoptable by local self-help groups, rural women and youth and entrepreneurs in urban and semi-urban areas.
Design/methodology/approach
Conventional binder used for making snacks, i.e. rice flour was partially replaced by different sources of antioxidant DFs, i.e. oat flour (T1 – 10%), finger millet flour (T2 – 5%) and amaranth flour (T3 –15%) to prepare spent hen snack sticks (SHSS). The snacks were then packaged in low density polyethylene (LDPE) pouches and evaluated for their storage stability at ambient temperature for a period of 35 days. Their physico-chemical, sensory and microbiological quality was evaluated at a regular interval of 7 days. The proximate composition of developed SHSS was compared to commercially available snack products (chakli/murukku – snacks without meat).
Findings
The fibre-enriched SHSS showed significant improvement in nutritive value, as they contained more fibre (p = 0.001) and protein (p = 0.029) than control SHSS. When compared to commercially available snack product SHSS showed three-fold significant increase in protein (p = 0.000) and ash content (p = 0.001) and only 11%–12% total fat as compared to 31% fat in the market-available product. The most acceptable treatment in terms of overall sensory quality and nutritional aspects was T3; however, T2 was more shelf-stable during the storage period. The study showed that fibre-enriched snacks can be stored at ambient temperature for up to 35 days without substantial loss in physico-chemical, sensory and microbial quality. Hence, substituting rice flour with DFs can lead to the development of products with better sensory attributes and improved functionality.
Social implications
The simplicity of the product in terms of composition, machinery and low production costs makes it an easily adoptable one by small-scale entrepreneurs, especially those belonging to semi-urban areas.
Originality/value
Incorporation of spent hen meat, a relatively cheap but abundant source of protein, in RTE products can serve as an effective way to alleviate protein malnutrition, whereas addition of fibre further improves the functionality of the product. The methodology can be easily taken up by small-scale entrepreneurs and create a market for snack-based functional meat products.
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In the mid-2000s, the operator of New York City’s mass transit network committed more than a half-billion dollars to military contractor Lockheed Martin for a security technology…
Abstract
In the mid-2000s, the operator of New York City’s mass transit network committed more than a half-billion dollars to military contractor Lockheed Martin for a security technology capable, in part, of inferring threats based on analysis of data streams, of developing response strategies, and taking automated action toward alerts and calamities in light of evolving circumstances. The project was a failure. This chapter explores the conceptualization and development of this technology – rooted in cybernetics – and compares its conceptual underpinnings with some situated problems of awareness, communication, coordination, and action in emergencies as they unfold in one of the busiest transport systems in the world, the New York subway. The author shows how the technology, with all the theatrical trappings of a “legitimate” security solution, was apparently conceived without a grounded understanding of actual use-cases, and the degree to which the complex interactions which give rise to subway emergency can be anticipated in – and therefore managed through – a technological system. As a case-study, the chapter illustrates the pitfalls of deploying technology against problems which are not well-defined in the first place, to the neglect of investments against much more fundamental problems – such as inadequate communication systems, and unstable relationships with emergency response agencies – which might offer guaranteed benefits, and indeed lay a firm groundwork for future deployment of more ambitious technology.
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