Numerical Investigation on Reduced Moment Resistance and Increased Reinforcement Spacing in Reinforced Concrete Wall Subjected to Blast Load

Numerical investigation becomes a highly demanding tool for the best design in engineering. With one validated numerical result available, further investigation is possible to conduct. Especially, for the expensive and limited access for civilian to conduct the test like a blast experiment. With the capability of Arbitrary Lagrange Euler (ALE) solver coupling approach between structure and air in AUTODYN, a detail three-dimensional assessment for RC wall on reduced moment resistance and increased reinforcement spacing are conducted. The RC wall has a cross-sectional dimension of 1829 mm x 1219 mm with wall thickness of 305 mm thickness of strip footing. It is subjected to 13.61 kg Trinitrotoluene (TNT) explosive at 1.21 m standoff distance from the centre. The numerical blast impact on RC wall indicated, although the horizontal and vertical flexural reinforcements are reduced from one of the simulated RC walls, it is capable of demonstrating an equivalent strength to the RC wall tested in the experiment

SAM-SoS: A stochastic software architecture modeling and verification approach for complex System-of-Systems

A System-of-Systems (SoS) is a complex, dynamic system whose Constituent Systems (CSs) are not known precisely at design time, and the environment in which they operate is uncertain. SoS behavior is unpredictable due to underlying architectural characteristics such as autonomy and independence. Although the stochastic composition of CSs is vital to achieving SoS missions, their unknown behaviors and impact on system properties are unavoidable. Moreover, unknown conditions and volatility have significant effects on crucial Quality Attributes (QAs) such as performance, reliability and security. Hence, the structure and behavior of a SoS must be modeled and validated quantitatively to foresee any potential impact on the properties critical for achieving the missions. Current modeling approaches lack the essential syntax and semantics required to model and verify SoS behaviors at design time and cannot offer alternative design choices for better design decisions. Therefore, the majority of existing techniques fail to provide qualitative and quantitative verification of SoS architecture models. Consequently, we have proposed an approach to model and verify Non-Deterministic (ND) SoS in advance by extending the current algebraic notations for the formal models as a hybrid stochastic formalism to specify and reason architectural elements with the required semantics. A formal stochastic model is developed using a hybrid approach for architectural descriptions of SoS with behavioral constraints. Through a model-driven approach, stochastic models are then translated into PRISM using formal verification rules. The effectiveness of the approach has been tested with an end-to-end case study design of an emergency response SoS for dealing with a fire situation. Architectural analysis is conducted on the stochastic model, using various qualitative and quantitative measures for SoS missions. Experimental results reveal critical aspects of SoS architecture model that facilitate better achievement of missions and QAs with improved design, using the proposed approach

Preliminary study on properties of oil palm shell lightweight concrete with cockle shell as mixing ingredient

Environmental pollution caused by the dumping of oil palm shell (OPS) from palm oil mill and cockle shell from cockle trade has initiated early exploration to discover the potential of these waste incorporated in concrete production. The present research investigates the effect of integrating crushed cockle shell as partial fine aggregate replacement on compressive strength and flexural strength of OPS lightweight aggregate concrete. A total of five mixes were prepared. OPS lightweight aggregate concrete containing 100% river sand was used as control specimen. Other mixes were produced by varying the percentage of crushed cockle shell by weight of sand. All specimens were water cured for 28 days before subjecting it to compressive strength and flexural strength. The finding shows the concrete exhibit strength increment when crushed cockle shell is added as partial fine aggregate replacement. Conclusively, crushed cockle shell has the potential to be used as mixing ingredient in OPS lightweight concrete production

Anticonvulsant activity of nitrendipine in albino mice

Background: The objective is to evaluate the anticonvulsant activity of nitrendipine in seizure-induced mice.Methods: Albino mice (25-30 g) of either sex were randomly selected and divided into four groups of six mice each. After overnight fasting, Group I received 0.25 ml of propylene glycol and served as the control, Group II received valproic acid (110 mg/kg orally) as standard, Groups III received 5 mg/kg of nitrendipine and 100 mg/kg of valproic acid, Group IV received 5 mg/kg of nitrendipine and 75 mg/kg of valproic acid, and Group V received 5 mg/kg of nitrendipine and 50 mg/kg of valproic acid all of which were administered orally 60 mins prior to the test in this acute study. The anticonvulsant activity was screened using maximal electroshock (MES) model and pentylenetetrazole (PTZ) model.Results: The nitrendipine showed a considerable reduction in the duration of hindlimb extensor phase in MES model and also delayed the latency of seizures induced by PTZ when compared with control group. The probable mechanism of anticonvulsant action of nitrendipine could be due to its interference with the gamma amino butyric acid type aminergic mechanism, modulation of nicotinic, and N-methyl-D-aspartate receptors.Conclusion: Nitrendipine possesses the anticonvulsant activity and has a beneficial role in epilepsy

Periwinkle shell as mixing ingredient in concrete: A review

Growing population which also pushes for rising demand for seafood results in a generation of seashells which are thrown as environmental pollution waste after the edible meat is consumed. Meanwhile, the utilisation of natural resources as mixing ingredients for the production of concrete materials continues to increase over the year. The use of periwinkle shells as mixing ingredients in concrete materials can lower the dependency on natural aggregate supply. This paper discusses the properties of periwinkle shell and method of treatment prior to their usage as a cement and coarse aggregate as well as the mechanical properties of concrete produced using this seashell waste. Overall, the replacement of periwinkle shell as cement and coarse aggregate must be integrated in a specified percentage to enhance the performance of the concrete. For cement replacement, 5% of replacement gives the highest strength, meanwhile 10% of replacement as coarse aggregate can meet the desired strength. The increase in the use of periwinkle shell quantity as cement or coarse aggregate replacement reduces concrete workaibility. The integration of periwinkle shell influences the compresssive strength of concrete. Accomplishment in replacing periwinkle shell as cement and coarse aggregate would reduce pollutiion due to shell dumping and save natural resources. However, further investigation in terms of durability properties is recommended

Effect of sodium hydroxide on mechanical characteristics of kenaf fibers reinforced concrete

This article shows the experimental analysis of sodium hydroxide (NaOH) effects on the mechanical properties upon the addition of kenaf fibres to the concrete mixture. The compression and flexural tests were carried out on seven different concrete mixtures for 28 days to evaluate the mechanical characteristics. Hence, the experimental trials comprise of seven different mixtures of concrete; the control (without the addition of kenaf fibre) was represented as the first mixture. The following six concrete mixtures contain different kenaf fibre volume fractions (1% and 2%); they were treated with 1%, 3% and 6% of sodium hydroxide concentrations in order to investigate their performances. The experimental results show that the compressive and flexural strengths of kenaf fibres reinforced concrete increase as sodium hydroxide concentration increases. Besides, it is worth noting that the addition of kenaf fibres has an insignificant effect on the compressive strength of the concrete owing to the reduction in concrete density. Therefore, the results of this study demonstrated that the concrete flexural strength increased to up to 12%) upon the addition of 1% kenaf fibre associated with 6% NaOH. Moreover, the failure state increasingly changed to ductile from brittle

Strength and chloride penetration performance of concrete using coal bottom ash as coarse and fine aggregate replacement

Since 1987, Malaysia had used coal as a product to generate electricity. One of the main or the largest power plant in Malaysia is Tanjung Bin power plant at kukup, Johor. As a coal-based power plant, tonnes of coal bottom ash had been burned every day and the waste is wasted without specific economic benefit. Other than that, the waste generated are dangerous as it involved in environmental risk such as landfill ash reservoir. Therefore, this paper presents one of the alternative ways to manage the coal waste by cooperative it into concrete. This research study focuses on strength and durability performance of the concrete containing coal bottom ash as a coarse and fine aggregates replacement. The tests conducted was workability on fresh concrete, compressive strength test and chloride penetration test in 5% sodium chloride. The results show that the concrete containing coal bottom ash has low workability compare with normal concrete without coal bottom ash. Compressive strength test with coal bottom ash resulted higher than normal concrete. In chloride solution, the concrete containing coal bottom ash replacement shows better performance compare to normal concrete. Thus, it can be concluded that by using coal bottom ash in concrete as fine and coarse aggregates replacement, the performance in term of strength and chloride resistance are better compare to normal concrete. On the other hand, by using it in concrete, the waste generated dump in landfill can be reduced

Strength and chloride penetration performance of concrete using coal bottom ash as coarse and fine aggregate replacement

Since 1987, Malaysia had used coal as a product to generate electricity. One of the main or the largest power plant in Malaysia is Tanjung Bin power plant at kukup, Johor. As a coal-based power plant, tonnes of coal bottom ash had been burned every day and the waste is wasted without specific economic benefit. Other than that, the waste generated are dangerous as it involved in environmental risk such as landfill ash reservoir. Therefore, this paper presents one of the alternative ways to manage the coal waste by cooperative it into concrete. This research study focuses on strength and durability performance of the concrete containing coal bottom ash as a coarse and fine aggregates replacement. The tests conducted was workability on fresh concrete, compressive strength test and chloride penetration test in 5% sodium chloride. The results show that the concrete containing coal bottom ash has low workability compare with normal concrete without coal bottom ash. Compressive strength test with coal bottom ash resulted higher than normal concrete. In chloride solution, the concrete containing coal bottom ash replacement shows better performance compare to normal concrete. Thus, it can be concluded that by using coal bottom ash in concrete as fine and coarse aggregates replacement, the performance in term of strength and chloride resistance are better compare to normal concrete. On the other hand, by using it in concrete, the waste generated dump in landfill can be reduced

Serotonin Augments Gut Pacemaker Activity via 5-HT3 Receptors

Serotonin (5-hydroxytryptamine: 5-HT) affects numerous functions in the gut, such as secretion, muscle contraction, and enteric nervous activity, and therefore to clarify details of 5-HT's actions leads to good therapeutic strategies for gut functional disorders. The role of interstitial cells of Cajal (ICC), as pacemaker cells, has been recognised relatively recently. We thus investigated 5-HT actions on ICC pacemaker activity. Muscle preparations with myenteric plexus were isolated from the murine ileum. Spatio-temporal measurements of intracellular Ca2+ and electric activities in ICC were performed by employing fluorescent Ca2+ imaging and microelectrode array (MEA) systems, respectively. Dihydropyridine (DHP) Ca2+ antagonists and tetrodotoxin (TTX) were applied to suppress smooth muscle and nerve activities, respectively. 5-HT significantly enhanced spontaneous Ca2+ oscillations that are considered to underlie electric pacemaker activity in ICC. LY-278584, a 5-HT3 receptor antagonist suppressed spontaneous Ca2+ activity in ICC, while 2-methylserotonin (2-Me-5-HT), a 5-HT3 receptor agonist, restored it. GR113808, a selective antagonist for 5-HT4, and O-methyl-5-HT (O-Me-5-HT), a non-selective 5-HT receptor agonist lacking affinity for 5-HT3 receptors, had little effect on ICC Ca2+ activity. In MEA measurements of ICC electric activity, 5-HT and 2-Me-5-HT caused excitatory effects. RT-PCR and immunostaining confirmed expression of 5-HT3 receptors in ICC. The results indicate that 5-HT augments ICC pacemaker activity via 5-HT3 receptors. ICC appear to be a promising target for treatment of functional motility disorders of the gut, for example, irritable bowel syndrome