40 research outputs found

    Performance of asphaltic concrete modified with recycled crushed bricks

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    The pavement industry relies greatly on this conventional material in constructing the road. However, the shortage of the mined material has led to the need of finding alternative with local materials to partially substitute the asphalt components. The conventional pavement industry also contributed to thermal and greenhouse emission resulting from the mining activities. In addition, throughout the year, the amount of construction and demolition (C&D) waste generated from civil construction activities particularly in Malaysia is increasing in alarming rate. Recycling the C&D waste specifically in bricks is viewed as reasonable potential as aggregate modifier in the impulse for greener and sustainable asphalt pavement production. In this paper, recycled crushed bricks (RCB) is introduced to bituminous wearing course as partial replacement for coarse aggregates. The coarse aggregate is partially replaced with RCB in proportions of 0%, 10%, 20%, 30% and 40% by weight. This study summarizes the results of laboratory evaluation of Los Angeles Abrasion Value, Aggregate Crushing Value and Marshall Test. Results show that asphaltic concrete modified with 10% RCB has the lowest abrasion and crushing values which were 20.2% and 30% respectively. Similarly, the mix has the highest Marshall Stability and lowest flow which 15.61 kN and 3.37 mm respectively. Thus, partial replacement of coarse aggregates with 10% RCB in bituminous mix is suitable to be used in wearing course and can be used as alternative material in bituminous mix to reduce the dependency on natural aggregates and utilize the C&D waste efficiently

    Analysis of Optimal Motion Performance for Underactuated Gantry Crane System using MOPSO with Linear Weight Summation Approach

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    This paper present the development of Multi-Objective Particle Swarm Optimization (MOPSO) with Linear Weight Summation (LWS) approach to enhance the effectiveness and efficiency of Gantry Crane System (GCS). The purpose of using LWS is to control the desired trolley position and payload oscillation according to the Settling Time (Ts), Steady State Error (SSE) and Overshoot (OS). The effectiveness of variation in weight summation is observed to find the optimal motion performances of the system. It demonstrated that GCS is able to achieve the goals while able to move the trolley as fast as possible to the desired position with low payload oscillation. Through this approach, the best optimal motion performances can be achieved by setting similar value of weightage for OS and Ts and reduce the priority for SSE

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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    Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

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    Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Hybrid membrane filtration-advanced oxidation processes for removal of pharmaceutical residue

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    Reports of pharmaceuticals exist in surface water and drinking water around the world, indicate they are ineffectively remove from water and wastewater using conventional treatment technologies. The potential of adverse effect of these pharmaceuticals on public health and aquatic life, also their continuos accumulation have raised the development of water treatment technologies. Hybrid treatment processes like membrane filtration and advance oxidation processes (AOPs) are likely to give rise to efficient simultaneous degradation and separation mechanisms. Conventional membrane filtration techniques can remove the majority of contaminants, but the smallest, undegraded, and stabilized pharmaceutical wastes persist in the treated water. After some 20 years, researchers have recognized the important role of AOPs in the treatment of pharmaceutical wastewater because these technologies are capable of oxidizing recalcitrant, toxic, and non-biodigradable compounds into numerous by-products and finally, inert end-products via the intermediacy of hydroxyl and other radicals. Evidently, membranes are subjected to the fouling phenomenon by the contaminants in wastewater, hence resulting in a reduction of clean water flux and increase in energy demand. In such situations, these membrane hybrid AOPs exert a complementary effect in the elimination of membrane fouling, thus enhancing the performance of the membrane. Therefore, in this review, we describe the basic aspects of the removal and transformation of certain pharmaceuticals via membranes and AOPs. In addition, information and evidences on membrane hybrid AOPs in the field of pharmaceutical wastewater treatment is also presented

    Newly developed aggregate gradation for five asean countries

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    This paper presents the new aggregate gradation of the porous asphalt (PA) mixture in five Asean countries including Malaysia, Indonesia, Vietnam, Thailand and Singapore. The PA aggregate gradation need to be developed as it may suit all of the countries and the air voids content for Asean countries can be standardized. This study was carried out to investigate the air voids properties. Several aggregate testing should be conducted in order to get the new porous asphalt aggregate gradation that suits all Asean countries. Sieve analysis test was conducted to see the patterns of the aggregate gradation curve. Sieve analysis test were tested three times for each of the countries to get the best average. The results were then plotted in one graph for all countries to be evaluated. From the analysis, Singapore specification started with 0.075mm, followed by 0.15mm, 0.3mm, o.6mm and 2.36mm are seems to have all the criteria in terms of aggregate gradations for fine aggregate and the rest are from Thailand aggregate specification for lower line while for upper line, Vietnam specifications were proved to have all the criteria within all five countries gradations

    Newly developed aggregate gradation for five ASEAN countries

    Get PDF
    This paper presents the new aggregate gradation of the porous asphalt (PA) mixture in five Asean countries including Malaysia, Indonesia, Vietnam, Thailand and Singapore. The PA aggregate gradation need to be developed as it may suit all of the countries and the air voids content for Asean countries can be standardized. This study was carried out to investigate the air voids properties. Several aggregate testing should be conducted in order to get the new porous asphalt aggregate gradation that suits all Asean countries. Sieve analysis test was conducted to see the patterns of the aggregate gradation curve. Sieve analysis test were tested three times for each of the countries to get the best average. The results were then plotted in one graph for all countries to be evaluated. From the analysis, Singapore specification started with 0.075mm, followed by 0.15mm, 0.3mm, o.6mm and 2.36mm are seems to have all the criteria in terms of aggregate gradations for fine aggregate and the rest are from Thailand aggregate specification for lower line while for upper line, Vietnam specifications were proved to have all the criteria within all five countries gradations

    Stress and strain characteristic of stone mastic asphalt incorporating eggshell powder

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    Stone mastic asphalt (SMA) is a type of gap graded asphalt mixture. Due to large difference between the gap of large and small size aggregate, this type of mixture suffers a few drawbacks such as low resistance towards permanent deformation. Thus, the usage of ecofriendly and sustainable additive is crucial in enhancing the performance of SMA. Thus, this study is utilizing various amount of eggshell powder as asphalt modifier. Among the tests involve to evaluate the stress-strain characteristic of modified SMA are Resilient Modulus Test and Dynamic Creep Test. From the test, it shows that the addition of 4% eggshell powder produces the highest value of resilient modulus and lowest value of dynamic creep for SMA. In conclusion, this study proves that the eggshell powder is capable in enhancing the performance of SMA especially in terms of permanent deformation resistance

    Stress and strain characteristic of stone mastic asphalt incorporating eggshell powder

    Get PDF
    Stone mastic asphalt (SMA) is a type of gap graded asphalt mixture. Due to large difference between the gap of large and small size aggregate, this type of mixture suffers a few drawbacks such as low resistance towards permanent deformation. Thus, the usage of ecofriendly and sustainable additive is crucial in enhancing the performance of SMA. Thus, this study is utilizing various amount of eggshell powder as asphalt modifier. Among the tests involve to evaluate the stress-strain characteristic of modified SMA are Resilient Modulus Test and Dynamic Creep Test. From the test, it shows that the addition of 4% eggshell powder produces the highest value of resilient modulus and lowest value of dynamic creep for SMA. In conclusion, this study proves that the eggshell powder is capable in enhancing the performance of SMA especially in terms of permanent deformation resistance
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