Impact of europium concentration on thermal and absorption features of amorphous tellurite media

Improving the structural and optical properties of tellurite glasses via optimized doping of rare earth ions is an outstanding issue in materials science. Tellurite glasses doped with trivalent europium (Eu3+) are successfully prepared using conventional melt quenching technique. Glasses with chemical composition of (80-x)TeO2-10PbO-10ZnO-(x)Eu2O3 where 0 ≤ x ≤ 2.0 mol% are obtained. The influence of Eu3+ ions concentration on the thermal and absorption properties of the synthesized glasses is investigated using Differential Thermal Analyzer (DTA) and UV-VIS Spectroscopy. DTA curves in the temperature range of 50-1000 °C at a heating rate of 10 °C/min are used to determine the temperature of glass transition, crystallization, melting and in turn the thermal stability. DTA revealed that the increase in the Eu3+ contents improved the thermal stability. This observation is attributed to the alteration of the glass network structure via the creation of non-bridging oxygen. The room temperature absorption spectra recorded in the spectral region of 200 – 2000 nm exhibited three absorption peaks corresponding to 7F0 → 5D0, 7F0 → 5D1 and 7F0 → 5D2 transitions. The absorption intensity is found to be enhanced up to certain concentration of Eu3+ ions and then quenched. This is ascribed to the change in glass network structure and formation of defects through the cleavage of weak bonds and reduction in covalence states

Physical Simulation to Determine the Surface Water Profiles and Point Velocities for The Flow Conditions of Sungai Bunus Stilling

Over the years, Sungai Bunus has undergone hydrological changes and has become lower and narrower. Under a flood mitigation project, a flood diversion channel is proposed to reduce the volume of water in Sungai Bunus furthermore avoid the spill over into Sungai Klang and reduce flooding events in Kuala Lumpur city. This research describes the physical modelling of the flow state of the Sungai Bunus stilling basin. Physical model was constructed to verify the design criteria of the stilling basin that will be adopted for construction. Experimental work has been carried out both with and without piers under three specified discharges (52 L/s, 86 L/s and 121 L/s) and subsequently the measurement of the water surface height profiles and point velocities through the proposed system. Consequently, there are no significant differences of outcomes between the two circumstances. The results show that there is no overflow of water at discharges of 52 L/s and 86 L/s. The water level at the Sungai Bunus section starts to flood on one side of the package when the flowrate is 121 L/s both scenarios. All test conditions with and without piers shown that the point velocity measured at the beginning of the stilling basin (inlet) is much lower than the point velocity reported near the end of the stilling basin (outlet)

Physical Simulation to Determine the Surface Water Profiles and Point Velocities for The Flow Conditions of Sungai Bunus Stilling

Over the years, Sungai Bunus has undergone hydrological changes and has become lower and narrower. Under a flood mitigation project, a flood diversion channel is proposed to reduce the volume of water in Sungai Bunus furthermore avoid the spill over into Sungai Klang and reduce flooding events in Kuala Lumpur city. This research describes the physical modelling of the flow state of the Sungai Bunus stilling basin. Physical model was constructed to verify the design criteria of the stilling basin that will be adopted for construction. Experimental work has been carried out both with and without piers under three specified discharges (52 L/s, 86 L/s and 121 L/s) and subsequently the measurement of the water surface height profiles and point velocities through the proposed system. Consequently, there are no significant differences of outcomes between the two circumstances. The results show that there is no overflow of water at discharges of 52 L/s and 86 L/s. The water level at the Sungai Bunus section starts to flood on one side of the package when the flowrate is 121 L/s both scenarios. All test conditions with and without piers shown that the point velocity measured at the beginning of the stilling basin (inlet) is much lower than the point velocity reported near the end of the stilling basin (outlet)

Subacute oral toxicity assesment of ethanol extract of Mariposa christia vespertilionis leaves in male sprague dawley rats

The term Butterfly tea refers to decoction of Mariposa christia vespertilionis leaves which is widely consumed by cancer patients throughout Malaysia and has gained a huge popularity among Malaysians, not only cancer patients but also researchers to discover the real potential of this plant. Herein, the study is aimed at evaluating the possible toxicity in 28-day subacute oral toxicity of ethanolic extract M. christia vespertilionis in male Sprague Dawley rats. The 28-day subacute toxicity study was conducted to detect the no-observed adverse effect level (NOAEL). In this study, a total of 30 rats were divided into the control, 5% DMSO (vehicle), low dose (75 mg/kg), medium dose (125 mg/kg) and high dose (250 mg/kg) groups. The extract was administered daily from day 1 until day 28. At the end of the study, the animals were humanely sacrificed and assessed for the effect extract of Mariposa christia vespertilionis leaves on body weight and relative organ weights and haematological, biochemical and histopathological parameters. The haematological and serum biochemical parameters for the assessment of kidney and liver injuries were carried out. Results of haematological and serum biochemistry results showed no changes in the control and treated groups. In the histopathology, evaluation of kidney tissues in all treated groups showed no significant (p > 0.05) lesions. In contrast to kidney, liver tissues showed significant differences (p < 0.05) in lesions observed in low dose (430 mg), medium dose (700 mg) and high dose (1480 mg) groups with very mild, mild and mild to moderate lesion of hepatic necrosis, in the respective groups, and very mild hepatic degeneration and hepatitis were scored in all three groups

Some chemical carcinogens for leukaemia induction and their animal models

Animal models have been providing invaluable contributions to the better understanding of mechanisms of cancer (including leukaemias) development and effectiveness of most of the treatments. Chemical carcinogens are generally used to study the biology of cancers including leukaemias in many animal models, including rats and mice. The studies in most cases are aimed at the development and evaluation of cancer treatments and preventions. Some of the most common chemical carcinogens used in animal models for leukaemias include N-ethyl-N-nitrosourea (ENU), N-methyl-N-nitrosourea (MNU), dimethyl benz(a)anthracene (DMBA) and benzo(a)pyrene (BaP). This review provides highlights on different animal models of leukaemia induced by the chemical carcinogens mentioned earlier, at the same time discussing the contributions of these models to the leukaemia diagnosis in laboratory animal models for subsequent development of treatment

Evaluation of dermal toxicity study of ethanolic extract of Morinda citrifolia fruit in Spraque Dawley rats

Plant-based preparations are widely known to complement dermatological therapy, however toxic profiles of these plants are lacking and limited. To investigate the toxicity of Morinda citrifoliafruit ethanol extract applied to the skin of rats daily for 28days, thirty female Sprague Dawley rats were grouped into five groups (n=5 rats for each group) for each study. The experimental period was set at 14 days and 28 days for acute and subacute dermal toxicity, respectively. Rats in the treatment groups weretopically applied with the plant extract at three different doses; 2.5%, 5% and 10% on a shaved area of dorsal skin. For the acute toxicity study, rats received a single application of the extract on the firstday of study, whereas rats in the subacute toxicity study were applied with the extract every single day for 28 days. All rats were observed for changes in appearance and behaviour and were assessed for changes of body weight, organ weight, haematology, serum biochemistry and histopathological analyses as a result of the interaction between the extract and the skin. The study indicated no mortality and sudden changes in physical appearances and behaviour of the rats. The results depicted no significant changes (p> 0.05) in the body weight, relative organ weight, haematological and biochemical values. No microscopic changes were detected in the assessment of the liver, kidneys and skin. It is demonstrated that M. citrifoliafruit extract is non-dermal toxic and these results may be useful in determining dosages for further pre-clinical evaluation and product development

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Influence of bottom ash as a sand replacement material on durability of self-compacting concrete exposed to seawater

Concrete strength and durability performance under marine environment have been considered as challenging issue for many decades because seawater contains aggressive salts and it could affect the service life of concrete structure that is expected for the marine environment, such as offshore, harbour and coastal structures. Therefore, this study investigated the strength and durability performance of self-compacting concrete (SCC) containing Bottom Ash (BA) exposed to seawater under wetting-drying cycles. The exposure period for seawater was considered up to 180 days. Concrete mix incorporated BA from 10% to 30% by weight of sand with fixed water to binder ratio 0.4 with superplasticizer to produce 40 MPa concrete at 28 days. The performance of SCC was evaluated based on compressive strength, rapid migration test and depth of carbonation test. SCC with 10% BA gives satisfactory compressive strength and exhibits good resistance to chloride migration rate and it gives around 4.5% reduction in carbonation depth as compared to control mix at 180 days. The microstructural study also indicated that 10% BA form well shape calcium silicate hydrate gel, which delivers adequate compressive strength development. It was concluded that 10% BA as a sand replacement was found to be optimum, provides satisfactory strength and durability performance

The Strength Behavior of Self-Compacting Concrete incorporating Bottom Ash as Partial Replacement to Fine Aggregate

Abstract Self-compacting concrete which commonly abbrevited as SCC is a special concrete that have the ability to consilodate fully under its own self-weight without any internal or external vibration. This paper presents the experimental investigation carried out to study the strength of self-compacting concrete incorporating bottom ash at different replacement level of natural sand. The composite cement was used and the replacement level of bottom ash to natural sand is set up to 30 % by volume. The strength properties such as compressive strength, split tensile strength and flexural strength of the concrete at the age of 7 and 28 days of curing day were conducted. Results shows that the strength of the concrete with bottom ash increased up to replacement level 15% higher than control specimens. This show that bottom ash can be used as supplimentary cementitious materials, having the pozzolanic reactivty

Properties of Self-Compacting Concrete with Coal Bottom Ash Under Aggressive Environments

This book highlights the importance of incorporating coal bottom ash (CBA) into self-compacting concrete exposed to aggressive conditions. The incorporation of CBA in concrete is a sustainable strategy to prolong the lifespan of concrete. The content of the book is also regarded as a solution to the environmental issue. It helps academics, researchers, and students to acquire a better understanding of the influence of coal bottom ash on the properties of concrete through four sequential chapters. The book first presents background information on concrete deterioration, and then the improvement in properties of self-compacting concrete with different percentages of CBA exposed to tap water, sulphate solution, chloride solution, and seawater