The Effect of Temperature on the Tribological Behavior of RBD Palm Stearin

The wide use of petroleum-based oils raises concerns with regard to pollution, and the rising of awareness of greenhouse gases has created a demand for the use of environmentally friendly and biodegradable lubricants for industrial applications. Vegetable oils are one of the bio-oils that have been promoted as a replacement for petroleum products, in part due to their environmentally friendly characteristics; they are nontoxic, biodegradable, and easy to dispose of. Many researchers have performed studies on sunflower oil, corn oil, and soy oil, but few have studied palm oil as a lubricant. Palm oil produced in a high-throughput manner could fulfill the demand for bio-based lubricants. In this study, the influence of temperature on friction and wear performance for refined, bleached, and deodorized (RBD) palm stearin and additive-free paraffinic mineral oil is presented. The experiments were conducted using a four-ball tribotester. Test temperatures of 55, 65, 75, and 85°C were used. The sliding speeds were set to 1,200 rpm. Experiments were run for 1 h under a 392.4 N load. The results of RBD palm stearin were compared with those of paraffinic mineral oil. The experimental results showed that the RBD palm stearin had better performance compared to paraffinic mineral oil in terms of reducing frictional constraints.     

Remembering John Bardeen: inventor of transistor

Transistor’s invention revolutionized global society by spawning electronics industry. John Bardeen is among one of the inventors of transistor. He was a genius and one of the most influential semiconductor Physicist of 20^th century who won two Nobel prizes in Physics.     

Cellular Automata Model for Predicting the Failure Pattern of Laterally Loaded Masonry Wall Panels

This paper introduces a technique that directly predicts the failure patterns of laterally loaded masonry panels based on the results of existing typical panels tested in the laboratory. The technique is based on the use of the cellular automata (CA). In this technique, the CA modeling is established to propagate boundary effects to zones within a panel. The corresponding rules for the state values of zones are derived from the proposed CA model, using appropriate transition functions. These state values are then used by the CA to establish zone similarity between two panels. Finally, the zone similarity is applied to establish locations of cracks on the panel. The technique is used in a novel way that eliminates the use of any numerical tools such as finite-element analysis (FEA). This technique is purely based on comparing the failure pattern of the base panel (a panel whose failure pattern is known from the laboratory tests) and unseen panels (panels not tested in the laboratory by the writers or with unknown failure patterns) subjected to the same type of loading and with similar boundary conditions to predict the failure load of the unseen panels.     

A Reliable Stochastic Numerical Analysis for Typhoid Fever Incorporating With Protection Against Infection

In this paper, a reliable stochastic numerical analysis for typhoid fever incorporating with protection against infection has been considered. We have compared the solutions of stochastic and deterministic typhoid fever model. It has been shown that the stochastic typhoid fever model is more realistic as compared to the deterministic typhoid fever model. The effect of threshold number T* hold in stochastic typhoid fever model. The proposed framework of the stochastic non-standard finite difference scheme (SNSFD) preserves all dynamical properties like positivity, bounded-ness and dynamical consistency defined by Mickens, R. E. The stochastic numerical simulation of the model showed that increase in protection leads to low disease prevalence in a population.     

Structure Preserving Algorithm for Fractional Order Mathematical Model of COVID-19

In this article, a brief biological structure and some basic properties of COVID-19 are described. A classical integer order model is modified and converted into a fractional order model with as order of the fractional derivative. Moreover, a valued structure preserving the numerical design, coined as Grunwald–Letnikov non-standard finite difference scheme, is developed for the fractional COVID-19 model. Taking into account the importance of the positivity and boundedness of the state variables, some productive results have been proved to ensure these essential features. Stability of the model at a corona free and a corona existing equilibrium points is investigated on the basis of Eigen values. The Routh–Hurwitz criterion is applied for the local stability analysis. An appropriate example with fitted and estimated set of parametric values is presented for the simulations. Graphical solutions are displayed for the chosen values of (fractional order of the derivatives). The role of quarantined policy is also determined gradually to highlight its significance and relevancy in controlling infectious diseases. In the end, outcomes of the study are presented.     

Evolution of ferroelectric and piezoelectric response by heat treatment in pseudocubic BiFeO<Subscript>3</Subscript>–BaTiO<Subscript>3</Subscript> ceramics

Heat treatment of ceramics is an important process to tailor the fine electromechanical properties. To explore the criteria for optimized heat treatment in a perovskite structure of (1–x)Bi_1.05FeO₃–xBaTiO₃ (BF–BT100x) system, the structural phase relation, ferroelectric and piezoelectric response of BF–BT36 and BF–BT40 ceramics prepared by furnace cooling (FC) and quenching process were investigated. The X-ray diffraction examination showed single pseudocubic perovskite structure for all the ceramics. The homogenous microstructure was obtained for all ceramics with relatively large grain size in the furnace cooled samples. Well saturated ferroelectric hysteresis loops and enhanced piezoelectric constant (d₃₃?=?97 pC/N) were achieved by quenching process. Dielectric curve of BF–BT36 showed large dielectric constant at its Curie temperature, however, BF–BT40 showed diffused relaxor-like dielectric anomalies. Quenched BF–BT36 samples showed typical butterfly like field induced strain curves, however negative strain decreased in BF–BT40 ceramics. From these investigated study, it is observed that BF–BT ceramics are very sensitive to the heat treatment process (furnace cooling and quenching) on the dielectric, electromechanical properties.     

Performance‐based evaluations of the tangible benefits of information networks with applications

This paper provides a new methodology for the evaluation of the tangible benefits of information networks, based on their utilization and performance. The methodology enables the evaluation of different tangible benefits including those resulting from time, movement, paper, and space savings. Copyright © 2000 John Wiley & Sons, Ltd.     

Analysis of the cost‐effectiveness of information networks with applications

This paper presents a methodology for the analysis of the cost‐effectiveness of information networks over a period of time. The cost‐effectiveness is considered to be associated with use‐dependent and use‐independent costs and benefits. Copyright © 2000 John Wiley & Sons, Ltd.     

Polydopamine as an intermediate layer for silver and hydroxyapatite immobilisation on metallic biomaterials surface

Hydroxyapatite (HA) coated implant is more susceptible to bacterial infection as the micro-structure surface which is beneficial for osseointegration, could also become a reservoir for bacterial colonisation. The aim of this study was to introduce the antibacterial effect of silver (Ag) to the biomineralised HA by utilising a polydopamine film as an intermediate layer for Ag and HA immobilisation. Sufficient catechol groups in polydopamine were required to bind chemically stainless steel 316 L, Ag and HA elements. Different amounts of Ag nanoparticles were metallised on the polydopamine grafted stainless steel by varying the immersion time in silver nitrate solution from 12 to 24 h. Another polydopamine layer was then formed on the metallised film, followed by surface biomineralisation in 1.5 Simulated Body Fluid (SBF) solution for 3 days. Several characterisation techniques including X-Ray Photoelectron Spectroscopy, Atomic Force Microscopy, Scanning Electron Microscopy and Contact Angle showed that Ag nanoparticles and HA agglomerations were successfully immobilised on the polydopamine film through an element reduction process. The Ag metallisation at 24 h has killed the viable bacteria with 97.88% of bactericidal ratio. The Ag was ionised up to 7 days which is crucial to prevent bacterial infection during the first stage of implant restoration. The aged functionalised films were considered stable due to less alteration of its chemical composition, surface roughness and wettability properties. The ability of the functionalised film to coat complex and micro scale metal make it suitable for dental and orthopaedic implants application.