413 research outputs found

    Reduction of axis acceleration of quarter car suspension using pneumatic actuator and active force control technique

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    This paper presents the design of a control technique applied to the pneumatic active suspension system of a quarter car model using controller with fuzzy logic embedded in the active force control component. The overall control system is decomposed into two loops. In the main loop the desired force signal is calculated using an active force control strategy with a sugeno fuzzy logic element which is being employed to estimate the mass needed to feed the control loop. A Mamdani fuzzy logic controller is implemented in the outer loop to design a force controller such that the desired force signal is achieved in a robust manner. The resulting control strategy known as fuzzy – active force controller (FLC-AFC) is used to control a nonlinear actuator attached between the sprung mass and the unsprung mass of the quarter car model. The performances of the proposed control method were evaluated and later compared to examine the effectiveness in suppressing the vibration effect of the suspension system. Resulting fuzzy active force control gives better results if compared to the fuzzy logic and the passive suspension system

    Low carbon building: Experimental insight on the use of fly ash and glass fibre for making geopolymer concrete

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    Due to the environmental impacts resulting from the production of Ordinary Portland cement (OPC), the drive to develop alternative binders that can totally replace OPC is gaining huge consideration in the construction field. In the current study, attempt was made to determine the strength characteristics of glass fibre-reinforced fly ash based geopolymer concrete. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) were used as alkaline solutions (for activation of geopolymer reaction) at 12, 16, 20 M. Glass fibres were added to the geopolymer concrete in varying proportions of 0.1e0.5% (in steps of 0.1%) by weight of concrete. A constant weight ratio of alkaline solution to fly ash content of 0.43 was adopted for all mixes. British standard concrete test specimens were cast for measuring compressive strength, splittensile strength, and flexural strength. Concrete specimens were cured by heating in oven at 90 �C for 24 h and natural environment, respectively. From the results, thermally cured concrete samples had better mechanical properties than the ambient (natural) cured samples. Thermally cured concrete specimen, containing 0.3% glass fibre and 16 M NaoH, achieved a maximum compressive strength of 24.8 MPa after 28 d, while naturally cured samples achieved a strength of 22.2 MPa. There was substantial increase in tensile strength of geopolymer concrete due to the addition of glass fibres. Split tensile strength increased by 5e10% in glass fibre-reinforced geopolymer concrete, containing 0.1e0.5% glass fibre and 16 M NaoH when compared to the unreinforced geopolymer concrete (1.15 MPa)

    Finite Element Analysis and Experimental Study on the Effect of Extrusion Ratio during Hot Extrusion Process of Aluminium Matrix Composites

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    The finite element (FE) analysis on the effect of extrusion process parameter namely, extrusion ratio at different billet temperatures on the plastic strain and strain rate of aluminium matrix composite during hot extrusion process has been dealt. The dynamic explicit FE code in ANSYS 15.0 workbench was used for simulation. The FE analysis was carried out on the SiC reinforced aluminium matrix composites for three extrusion ratios 4:1, 8:1 and 15:1, for the billet temperatures in the range 350 °C - 450 °C in steps of 50 °C. The plastic strain and strain rate were found to increase with increase in the extrusion ratio. A minimum strain and strain rate was found to occur at the billet temperature of 450 °C. The silicon carbide particles reinforced aluminium matrix composites were then extruded at the optimised temperature of 450 °C for various extrusion ratios as mentioned above. The effect of extrusion ratio on the microstructure and surface quality of extruded rod was studied

    Chemical profiling of fern Cheilosoria mysurensis (Wall. ex Hook.) Ching & Shing and its biological activity

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    Cheilosoria mysurensis (Wall. ex Hook.) Ching & Shing, a medicinal fern traditionally used to treat burns, throat pain and bone fracture. There is no any scientific report regarding anticancer studies of this species. The aim of the study was to find out the chemical components through GC/MS analysis with their antioxidant and cytotoxic activity. GC-MS analysis shows primary ingredients viz, Cis-9, 10-epoxyoctadecan-1-ol and Oxiraneundecanoic acid, 3-pentyl-, methyl ester, trans were present. High free-radical scavenging activity has been discovered in 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and showed the IC50 value of 52.13±0.33. Furthermore, C. mysurensis also showed good cytotoxic effects against DLA and EAC cell lines with values of 72.9% and 79.5% at 200 µg/ml dose respectively. Overall findings suggested that the identified chemical compounds proved to be rich in antioxidant property. Further, this fern can be a good resource for pharma industry to produce novel anti-cancer drugs

    Carbon Fiber Composites: A Solution for Light Weight Dynamic Components of AFVs

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    Changing circumstances across the world require armored fighting vehicle (AFV) of a country to be more agile, easily manoeuverable and transportable besides other key requirements like firepower and protection. Therefore, the AFV should be as light as possible. The use of conventional materials and techniques do not fulfill the requirement of light weight AFV. The composite materials having high specific modulus, specific strength and directional properties are the alternative substitution for reducing the weight. A customized design approach with proper selection of composite material is essential to make AFV components with required properties at lower weight as compared to the traditional approach. Special properties like resistance to moisture, solvents, UV degradation etc. could be imparted to the composite components by the use of proper additives or fillers. This paper deals with the development of dynamic members like road wheel, top roller and axle arm, whose count is always more in any AFVs, using carbon-epoxy composite material. The details of composite materials used and the manufacturing processes adopted are briefly discussed. The static load test carried out to assess the structural integrity as well as non-destructive tests (NDT) performed to detect the defects are also dealt in detail. Preliminary Finite Element Analysis and Multi-body Dynamic Analysis have also been discussed. These analyses have been done mainly to understand the sustainability and performance of the components developed under the given loading conditions

    Computational Analysis of Heat Transfer through Fins with Different Types of Notches

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    The Engine is one of the important component in an automobile which is subjected to high temperature and thermal stresses. In order to cool the engine the fins are another component which are used to dissipate the heat from the Engine. Fins are generally used to increase the heat transfer rate from the system to the surroundings. By doing computational flow analysis on the engine cooling fins, it is helpful to know about the heat dissipation rate and the Principle implemented in this project is to increase the heat transfer rate, so in this analysis, the fins are modified by putting different types of notches and are of same material. The knowledge of efficiency and effectiveness of the fins are necessary for proper designing of fins. The main objective of our analysis is to determine the flow of heat at various notches available and the analysis is done by using ANSYS – CFD Fluent software

    Ply-stacking effects on mechanical properties of Kevlar-29/banana woven mats reinforced epoxy hybrid composites

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    © The Author(s) 2022. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, https://creativecommons.org/licenses/by-nc/4.0/Development of new hybrid laminated composites of Kevlar-29 (K-29)/banana fiber (Musa acuminata) mats to meet future demand for fiber reinforced polymer (FRP) composites has been investigated. The different ply-stacking sequenced Kevlar (K)/natural (N) banana reinforced epoxy polymeric hybrid composite samples were designated as KN1, KN2, KN3, KN4, KN5 and KN6, in addition to NN7 and KK8 for single or non-hybrid FRP (control) composite samples. The ply-stacking effects on mechanical properties of all the laminated composite were investigated. The maximum tensile, flexural, impact and interlaminar shear strengths (ILSS) were obtained with sample KN4, because of the stacking of its Kevlar and natural banana mats, which was K2/N4/K2 of 8 layers and different from other stacking sequences. The percentage improvements on tensile strength of sample KN4 when compared with other hybrid composite samples KN1, KN2, KN3, KN5 and KN6 were 6.3, 4.4, 3.6, 13.1 and 11.3%, respectively. While, same optimum sample KN4 recorded highest flexural strength among hybrid samples with percentage improvements of 122.19, 70.97, 31.03 and 83.68% when compared with other hybrid samples KN2, KN3, KN5 and KN6, respectively. Similar trend of results was obtained for their tensile and flexural moduli. But, both hybrid composite samples KN3 and KN4 recorded higher impact strengths of 3.0 and 2.8 J, respectively, when compared with other hybrid counterparts. The tensile and flexural strengths of sample KN4 were 147.48 and 223.69 MPa, respectively. The tensile properties of various theoretical model were compared with experimental values.Peer reviewe

    3-Benzyl-6-benzyl­amino-1-methyl-5-nitro-1,2,3,4-tetra­hydro­pyrimidine

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    In the title compound, C19H22N4O2, the tetra­hydro­pyrimidine ring adopts an envelope conformation (with the N atom connected to the benzyl group representing the flap). This benzyl group occupies a quasi-axial position. The two benzyl groups lie over the tetra­hydro­pyridimidine ring. The amino group is a hydrogen-bond donor to the nitro group

    Extraction process optimization of flavonoid and in vitro amylase inhibitory effect of purified quercetin derivative from Amorphophallus paeoniifolius tubers

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    544-556Amorphophallus paeoniifolius (Elephant foot yam) is a prominent tuberous plant utilized across several parts of India to treat various ailments such as a tumour, haemorrhage, microbial infections, cough, bronchitis, diabetes, anaemia, and hepato-gastro and cardiovascular diseases. In this context, the present study aims to optimize the extraction process of the flavonoid and to study the in vitro amylase inhibitory effect of purified flavonoid moiety. The Shake flask method with different extraction solvents was adopted to quantify the flavonoid content. Central composite design (CCD) based response surface methodology (RSM) was formulated to optimize the extraction process. Three-dimensional preparative chromatography (3D PTLC) was executed to purify the flavonoid content and high-resolution liquid chromatography-mass spectrometry (HRLC-MS) was adopted to predict the structure. 3,5-dinitrosalicylic acid (DNS) based spectrophotometry method was used to determine the amylase inhibitory property. All the analyses were subjected to standard statistical tests. The developed model for the extraction optimization process was found to be near significant (P = 0.242) with temperature as a significant variable (P = 0.029), and a 107-fold increase (71.11±0.5 mg/g tissue) of flavonoid content was recorded. A strong yellow colour spot (flavonoid fraction) was eluted using 3D PTLC technique and the molecule was identified as quercetin derivative (m/z 447) by the direct MS method. Significant amylase inhibition (36.1±2.1%) recorded by purified quercetin derivative has documented the utilization of A. paeoniifolius tubers as classical traditional medicine

    Poly-Gamma-Glutamic Acid (γ-PGA)-based encapsulation of Adenovirus to evade neutralizing antibodies.

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    In recent years, there has been an increasing interest in oncolytic adenoviral vectors as an alternative anticancer therapy. The induction of an immune response can be considered as a major limitation of this kind of application. Significant research efforts have been focused on the development of biodegradable polymer poly-gamma-glutamic acid (γ-PGA)-based nanoparticles used as a vector for effective and safe anticancer therapy, owing to their controlled and sustained-release properties, low toxicity, as well as biocompatibility with tissue and cells. This study aimed to introduce a specific destructive and antibody blind polymer-coated viral vector into cancer cells using γ-PGA and chitosan (CH). Adenovirus was successfully encapsulated into the biopolymer particles with an encapsulation efficiency of 92% and particle size of 485 nm using the ionic gelation method. Therapeutic agents or nanoparticles (NPs) that carry therapeutics can be directed specifically to cancerous cells by decorating their surfaces using targeting ligands. Moreover, in vitro neutralizing antibody response against viral capsid proteins can be somewhat reduced by encapsulating adenovirus into γ-PGA-CH NPs, as only 3.1% of the encapsulated adenovirus was detected by anti-adenovirus antibodies in the presented work compared to naked adenoviruses. The results obtained and the unique characteristics of the polymer established in this research could provide a reference for the coating and controlled release of viral vectors used in anticancer therapy.This work was funded by the Ministry of Higher Education and Scientific Research (Iraq). This work was also partially funded by the Research Investment Fund, University of Wolverhampton (Wolverhampton, United Kingdom) and the Italian Ministry of University and Research (MIUR)
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