A practical macro-mechanical model for the bend capacity of fibre-reinforced polymer bars

Bent fibre-reinforced polymer bars embedded in reinforced concrete elements resist lower forces than straight counterparts due to strength losses at the bend, and such losses are difficult to calculate. This paper reports on an investigation into the effect of section geometry and bond, which led to a new macro-mechanical model to calculate the bend capacity of fibre-reinforced polymer bars. The proposed model uses a Tsai-Hill failure criterion and accounts for factors known to influence the bend capacity of the bars. A section factor, ignored in existing models, also accounts for the strength degradation due to the change in geometry at the bent portion of the bar. The model was calibrated using a set of 80 tests found in the literature and performed by the authors. The results indicated that, compared to existing equations, the proposed model predicts the bend strength of bars more accurately, with an average prediction to experiment ratio of 1.0 and a standard deviation of 0.25. Following validation and verification, appropriate values for the model parameters are recommended for design. The proposed model can lead to more economic design, by up to 15%

Solidification/stabilization technology for radioactive wastes using cement: an appraisal

Across the world, any activity associated with the nuclear fuel cycle such as nuclear facility operation and decommissioning that produces radioactive materials generates ultramodern civilian radioactive waste, which is quite hazardous to human health and the ecosystem. Therefore, the development of effectual and commanding management is the need of the hour to make certain the sustainability of the nuclear industries. During the management process of waste, its immobilization is one of the key activities conducted with a view to producing a durable waste form which can perform with sustainability for longer time frames. The cementation of radioactive waste is a widespread move towards its encapsulation, solidification, and finally disposal. Conventionally, Portland cement (PC) is expansively employed as an encapsulant material for storage, transportation and, more significantly, as a radiation safeguard to vigorous several radioactive waste streams. Cement solidification/stabilization (S/S) is the most widely employed treatment technique for radioactive wastes due to its superb structural strength and shielding effects. On the other hand, the eye-catching pros of cement such as the higher mechanical strength of the resulting solidified waste form, trouble-free operation and cost-effectiveness have attracted researchers to employ it most commonly for the immobilization of radionuclides. In the interest to boost the solidified waste performances, such as their mechanical properties, durability, and reduction in the leaching of radionuclides, vast attempts have been made in the past to enhance the cementation technology. Additionally, special types of cement were developed based on Portland cement to solidify these perilous radioactive wastes. The present paper reviews not only the solidification/stabilization technology of radioactive wastes using cement but also addresses the challenges that stand in the path of the design of durable cementitious waste forms for these problematical functioning wastes. In addition, the manuscript presents a review of modern cement technologies for the S/S of radioactive waste, taking into consideration the engineering attributes and chemistry of pure cement, cement incorporated with SCM, calcium sulpho–aluminate-based cement, magnesium-based cement, along with their applications in the S/S of hazardous radioactive wastes

The Suitability of Photocatalyst Precursor Materials in Geopolymer Coating Applications: A Review

Today, the building and construction sector demands environmentally friendly and sustainable protective coatings using inorganic coating materials for safe, non-hazardous, and great performance. Many researchers have been working on sustainable solutions to protect concrete and metal infrastructures against corrosion and surface deterioration with the intention of introducing green alternatives to conventional coatings. This article presents a review of developments of geopolymer pastes doped with different types of photocatalyst precursors including factors affecting geopolymer properties for enhancing coating with photocatalytic performance. Photodegradation using geopolymer photocatalyst has great potential for resolving harmless substances and removing pollutants when energized with ultraviolet (UV) light. Although geopolymer is a potentially new material with great properties, there has been less research focusing on the development of this coating. This study demonstrated that geopolymer binders are ideal precursor support materials for the synthesis of photocatalytic materials, with a significant potential for optimizing their distinctive properties

Cancer disparities in Southeast Asia: intersectionality and a call to action.

Southeast Asia has a population of over 680 million people—approximately half the population of India and twice the population of the United States—and is a region marked by rich and complex histories and cultures, dynamic growth, and unique and evolving health challenges.1 Despite the momentum of economic development, health inequalities persist. These inequities have been aggravated since the COVID-19 pandemic, which pushed millions further into poverty, possibly exacerbating health disparities, especially among populations who suffer vulnerabilities.2 Particularly salient are the challenges associated with providing adequate care for people with cancer, a leading cause of morbidity and mortality in the region.1,2 Cancer incidence and mortality in the region are projected to rise in the coming decades, given population growth and rapidly changing socioeconomic and geopolitical factors, as well as a host of interrelated and dynamic environmental, behavioral, and occupational risk factors.1, 2, 3 Large epidemiologic studies have demonstrated differences among Southeast Asian countries in terms of cancer incidence and mortality.3 Epidemiologic patterns can be attributed to variations in complex risk factors, access to screening and cancer care, and likely genetic predisposition.1, 2, 3 However, these differences also underscore that within each country exist richly diverse populations that experience disparities in cancer risk, screening, care access, outcomes, and survivorship in ways that require further examination. We draw attention to disparities in cancer in Southeast Asian countries. We highlight the need to study cancer disparities affecting minoritised groups in Southeast Asia—not only along lines of race/ethnicity, but also people minoritised along lines of sex/gender, socioeconomic status, religion, geography, and others. We highlight the intersectionality of elements of an individual's identity. Intersectionality, developed by critical race theorist Professor Kimberlé Crenshaw in 1989, is an analytic framework borne out of Black American feminist scholarship, that examines how a person's sociopolitical identities lead to disparate balances of privilege and discrimination.4 An intersectional approach would demonstrate that an individual or a community does not only experience economic poverty as the sole barrier to improved health; such an approach would examine how other identities such as religion or immigration status affect access to care. These different social determinants of health are not mutually exclusive; their interrelationships are complex, with consequences for health.5 We leverage the intersectional approach, which parallels the inherently syncretic cultures and histories of Southeast Asian nations, and explore how these identities impact access to cancer care. Meaningful cancer research focusing on peoples of Southeast Asia could present many opportunities for intervention and improvement