Robust vehicle suspension system by converting active and passive control of a vehicle to semi-active control ystem analytically

This research article deals with a simplified translational model of an automotive suspension system which is constructed by considering the translation motion of one wheel of a car. Passive Vehicle Suspension System is converted into Semi Active Vehicle System. Major advantage achieved by this system is that it adjusts the damping of the suspension system without the application of any actuator by using MATLAB® simulations. The semi-active control is found to control the vibration of suspension system very well

Biological activities of aerial parts of Paeonia emodi wall

The ethanolic extract derived from the aerial parts of Paeonia emodi was screened for various in vitro biological activities including antifungal, antibacterial, insecticidal, phytotoxic and haemagglutination activities. General toxicity (brine shrimp lethality assay) of this extract has also been assessed. The extract was found to possess excellent phytotoxicity against Lemna minor L., moderate heamagglutination activity against human erythrocytes and reasonable insecticidal activity against Bruchus pisorum. The crude extract did not display any antifungal or antibacterial activity against the fungi and bacteria used in this study. No significant general toxicity was observed with the extract at tested concentrations

Maximising the interfacial toughness of thin coatings and substrate through optimisation of defined parapmeters

The influence of three parameters, i.e. interfacial roughness λ, coating thickness h and impurity radius r at the coating–substrate interface on interfacial toughness, has been investigated within the framework of two approaches, i.e. thermodynamics and fracture mechanics. The governing equations for both the approaches have been derived independently and then fused to form a governing law for evaluating the interfacial toughness. The analysis in this paper which considers three parameters (λ, h and r) has been divided into three setups. Each setup is used to analyse the effect of one variable parameter on interfacial toughness while keeping the other two parameters constant. Three samples for each setup were prepared considering the requirements of constant and variable parameters for each setup. Simulation techniques founded on the experimental studies have been developed during this research in order to find the optimised values of three parameters. These optimised values act as critical values (boundary point) between coating fail-safe and coating fail conditions. The experiment employed ASTM-B117 test, which is used to analyse the interfacial toughness of samples under each setup. These experiments showed excellent, quantitative agreement with the simulation trends predicted by the theoretical model

A theoretical and experimental study of HFE-7000 in a small scale solar organic Rankine cycle as a thermofluid

The use of thermofluids with boiling temperatures lower than the water, allows the operation of low and medium temperature solar thermal systems on an Organic Rankine Cycle (ORC) to generate both mechanical and heat energy. At the same time, the selection of appropriate thermofluid is an important process and has a significant effect both on the system performance and the environment. Conventional thermofluids such as Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFCs) have high ozone depletion (ODP) and high global warming (GWP) potential. It is therefore important to investigate novel and environmentally friendly thermofluids to address environmental impacts as global warming and ozone layer depletion. Hydrofluoroethers (HFEs) have zero ODP and relatively low GWP and therefore can be used as a replacement for CFCs and HCFCs. In this study, a small scale solar ORC is designed and commissioned to use HFE 7000 as a thermofluids. The system has a flat plate collector and a vane expander as the heat source and prime mover of the cycle respectively. The system performance is determined through energy analysis. Then, a mathematical model of the cycle is developed and the effect of various operating conditions on the components, as well as the whole cycle is examined through performing simulation analyses. Both the experimental and theoretical research indicates that HFE 7000 offers a viable alternative to be used efficiently in small scale solar ORCs to generate mechanical and heat energy

Callus induction via different growth regulators from cotyledon explants of indigenous chick pea (Cicer arietinum L.) cultivars KK-1 and Hassan-2K

Callus induction from cotyledon explants was studied in indigenous chick pea (Cicer arietinum L.) cultivars KK-1 and Hassan-2K on MS and B5 media containing different combinations and concentrations of growth regulators. Different MS and B5 callusing media containing varying level of 2, 4-D (2 and 4 mg/l), NAA (0.50 and 1 mg/l), BAP (5 and 10 μM) and their combinations were tested for callus induction response. Percent callus and callus fresh weight (g) were recorded after two and four weeks of culture for both genotypes. For KK-1 cultivar, the maximum callus frequency (71 and 97%) followed by (65 and 96%) were observed on 4 mg/l 2,4-D+5 μM BAP in MS and 4 mg/l 2,4-D in B5 media, respectively after two and four weeks of culture. Similarly, the highest callus fresh weight (0.411 and 0.787 g) were also recorded for MS+4 mg/l 2,4-D+5 μM BAP in contrast to B5 where the highest callus weight (0.401 and 0.693 g) was achieved on 4 mg/l 2,4-D only. In Hassan -2K, the highest callus % (68 and 96) and fresh weight (0.572 and 0.821 g) were recorded on MS+4 mg/l 2,4-D+0.50 mg/l NAA after two and four weeks of culture, respectively. In B5 medium, 2,4-D+BAP combination produced average callus induction response for both cultivars.Key words: Callus induction, chick pea cotyledons, growth regulators

Phyto-agglutinin, total proteins and amino assimilating enzymatic activity of indigeneous chickpea (Cicer arietinum L.) cultivars

Biochemical studies were carried out with in vitro micropropagated plantlets of two indigenous cultivars of chickpea (Cicer arietinum L.), KK-1 and Hassan-2K, where extract from shoots, leaves, roots, and reproductive organs were determined for human erythrocyte agglutination (by mixing the lectin containing extract 1:1 with a 2% erythrocyte suspension), protein profiling and the amino assimilating (glutamine synthetase) enzymatic activity. Both of KK-1 and Hassan-2K cultivars extract showed highly phyto-agglutination of human erythrocytes with reproductive organs and other tissues, which represents the presence of potent lectins (phyto-agglutinin). The amino assimilating enzymatic activity of green leaves of Hasan-2K was found higher (3.545 GS μmol.gfw-1.min-1) as compared to KK-1 (2.873 GS μmol.gfw-1.min-1). Protein content profile showed variation in bulk proteins of various tissues, higher (12.634 μg/gfw) and (2.987 μg/gfw) in reproductive organs of KK-1 and Hasan-2K, respectively.Key words: Chickpea, glutamine synthetase, glyco-protein, lectin, phyto-agglutinin

A Predictive Model for Life Assessment of Automotive Exhaust Mufflers Subject to Internal Corrosion Failure due to Exhaust Gases Condensation

A study has been presented of pitting corrosion on internal walls of automotive exhaust muffler due to exhaust gases condensation. The problem mainly exists in the rear section of exhaust system close to tail end pipe such as muffler, especially when the temperature of muffler does not go up during short distance run or winter. The water vapor condenses on the muffler's inner wall in the form of water droplets. The dissolution of corrosive gases which are coming from internal combustion of engine as well as condensation of low-pH acidic vapors in the water droplet can cause severe pitting corrosion on standard exhaust steel. In this work, an experiment is reported for internal corrosion, by using mufflers as test bed subjected to different environmental conditions. Based on observations, a mechanistic model has been developed which involves three main techniques (i) the dropwise condensation technique predicts the condensation rate and is based on heat and mass transfer theory (ii) the species breakdown in the droplet is established through the main thermodynamic and chemical equilibrium (iii) the pitting corrosion involving pit depth is predicted using electrochemical kinetic reactions, species transport and chemical reactions occurring inside the droplet. Lastly, the accuracy of model has been validated by comparison between experimental and predicted results showing a good agreement

An Optimised Approach of Protecting and Sustaining Large Vehicle System

This article is a synopsis of our research and highlights the outcomes and its impact. It was conducted for the development of a sustainable approach to protect and sustain large vehicles in sheltered environment for their enhanced longevity. In this research various modes of failures linked directly or indirectly to the structural ageing of large vehicles were identified, measured, and analysed. Based upon the research conducted; A frame-work to retard structural failures and in-situ condition monitoring has been proposed with an objective to prolong the structural longevity cost effectively

59. Early and late results of routine leaflet augmentation for complete atrio-ventricular septal defect repair

Complete AVSD (CAVSD) is characterized by the presence of a common atrio-ventricular (AV) orifice, an inter-atrial communication, and a ventricular septal defect (VSD). Results of surgical correction of atrio-ventricular septal defects (AVSDs) have improved over the last decades; however, the need for reoperation for left atrio-ventricular valve regurgitation, after primary AVSD repair remains a major concern. The aim of our study is to assess the outcome of the routine leaflet augmentation technique in CAVSD repair. A retrospective database and chart review analysis of all patients who underwent AV canal repair at king Abdul-Aziz Cardiac Center during period from 1999 to September 2014 was conducted. Demographic data, associated anomalies, operative data, ICU and hospital course were reviewed. Early outcomes were reviewed for postoperative complications (Chylothorax, complete AV block, Arrhythmias, early mortality) and late outcomes were reviewed for Left AV valve regurgitation requiring for re-intervention and late mortality. Two hundred and sixty patients underwent leaflet augmentation technique to repair complete AVSD, between January 1999 and September 2014. The mean age was (131.5months), and mean weight (6.06kg). A variety of concomitant procedures were performed at the time of repair of the CAVSD, including a total of 49 patients (18.8%) who underwent PDA ligation. Repair of TV (Right AV valve) was performed in 11 patients (4.2%), 9 patients (3.46%) required RVOTO resection, in 5 patients (1.92%), PA plasty was done and 2 patients (0.76%) required ECMO after CAVSD repair. Regarding reoperations, a total of 17 patients (of 260) required reoperation after initial CAVSD repair. The most common indication for reoperation was left AV valve regurgitation in 16 patients (6%) in the follow up period up to 15years. One patient (0.38%) required diaphragmatic plication. The overall mortality was 3 patients (1.1%). Leaflet augmentation for the repair of the complete AVSD, represent a good surgical alternative technique, allows for good exposure, good LAVV reconstruction and close to anatomical repair and results in reduced incidence of late Left atrio-ventricular valve regurgitation

Modeling the Effect of Residual and Diffusion-Induced Stresses on Corrosion at the Interface of Coating and Substrate

The effect of residual and diffusion induced stresses on corrosion at the interface of coating and substrate has been analysed within a multidisciplinary approach i.e. material science, solid mechanics and electrochemistry. A self-consistent equation for corrosion current density, involving the combined effect of residual stress and diffusion induced stress is developed. The influences of temperature, moduli ratio, thickness ratio, thermal mismatch ratio and residual stress gradient of coating and substrate on the corrosion current density are then discussed. Results indicate that when the thermal expansion of coating is greater than substrate, the decrease in temperature from fabrication temperature accounts for the same direction of both the residual and the diffusion stresses. This behaviour increases the deflection of coating-substrate system and results in the evolution of tensile residual stress in the coating. The tensile stress opens the pre-existing coating micro crack allowing the diffusion of corrosive agents and therefore, accelerating the corrosion damage to the coating-substrate interface. The model is based on experimental observations conducted to understand the behaviour of corrosion at the coating-substrate interface in the presence of tensile or compressive residual stresses. At the end the model has been validated against the experimental results showing a good quantitative agreement between the predicted theoretical and experimental trends