Effect of spheroidized microstructure on the impact toughness and electrochemical performance of a high-carbon steel

The influence of cementite spheroidization on the impact toughness and electrochemical properties of a high-carbon steel has been thoroughly investigated in this study. Heavy warm rolling, followed by 2 h of annealing, has resulted in near-complete spheroidization, leading to a microstructure consisting of nano-cementite globules dispersed in the ultrafine-grained ferritic matrix. The Charpy impact test exhibited superior impact toughness with increased spheroidization. It is validated by the presence of abundant dimples in the fractographs of spheroidized specimens, in contrast to the as-received one that experienced a brittle failure due to its lamellar pearlitic structure. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) carried out in a 3.5% NaCl solution revealed that the corrosion resistance of the alloy gets improved with the increase in the degree of spheroidization. This is attributed to the lower susceptibility of the spheroidized specimen to microgalvanic corrosion owing to the minimum area of contact between nano-spheroidized cementite and ferrite, as elucidated with the help of EIS results aided by equivalent electrical circuit model.     

Preparation,characterization, and in vivo evaluation of nano formulations of ferulic acid in diabetic wound healing

Diabetes mellitus is most common disorder characterize by hyperglycemia. Chronic hyperglycemia may lead to over production of free radicals thereby results in oxidative stress which impaired healing of wounds. Ferulic acid (FA) has been shown to have antidiabetic and antioxidant properties. The aim of the present study was to develop Ferulic acid nanoparticles and to study its hypoglycemic and wound healing activities. Ferulic acid-poly(lactic-co-glycolic acid) (FA-PLGA) nanoparticles were prepared by nano precipitation method. The prepared FA-PLGA nanoparticles had an average size of 240?nm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis showed the prepared FA-PLGA nanoparticles were spherical in shape. Drug encapsulation assay showed that 88.49% FA was encapsulated in PLGA. Carbopol 980 was used to formulate FA-PLGA nanoparticles loaded hydrogel. FA-loaded polymeric nanoparticles dispersion (oral administration) and FA-loaded polymeric nanoparticles based hydrogel (topical administration) treated wounds were found to epithelize faster as compared with diabetic wound control group. The hydroxyproline content increased significantly when compared with diabetic wound control. Therefore, the results indicate that FA significantly promotes wound healing in diabetic rats.     

Room-Temperature Operation of a p-Type Molecular Spin Photovoltaic Device on a Transparent Substrate

The coupling of diverse degrees of freedom opens the door to physical effects that go beyond each of them individually, making multifunctionality a much sought-after attribute for high-performance devices. Here, the multifunctional operation of a single-layer p-type organic device, displaying both spin transport and photovoltaic effect at the room temperature on a transparent substrate, is shown. The generated photovoltage is almost three times larger than the applied bias to the device which facilitates the modulation of the magnetic response of the device with both bias and light. The device shows an increase in power conversion efficiency under magnetic field, an ability to invert the current with magnetic field and under certain conditions it can act as a spin photodetector with zero power consumption in the standby mode. The room-temperature exploitation of the interplay among light, bias, and magnetic field in the single device with a p-type molecule opens a way toward the development of efficient high-performance spin photovoltaic cells.     

Mix design procedure for recycled aggregate concrete

Conservation of natural resources and preservation of environment is the essence of any development. Use of recycled aggregate concrete (RAC) is one such attempt and is an answer to some of the problems in constructional engineering. The concept of using RAC is now gaining popularity and research in this direction has gained momentum. In this paper, the authors have identified the most suitable method of mix design for RAC, from amongst the available conventional methods of mix design. An influencing parameter is identified and an empirical relation is suggested to modify the influencing parameter. Mix design parameters thus obtained, enable RAC to attain the desired and designed target strength without attempting any trial mixes. The suggested modified procedure, however, demands 10% more cement which is considered quite reasonable and acceptable in view of the inferior quality of recycled aggregate.     

Leak detection in gas pipeline networks using an efficient state estimator. Part II. Experimental and field evaluation

In Part-I of this two part paper, a method is proposed for on-line leak detection and identification in gas pipeline networks using flow and pressure measurements. Simulations on two illustrative networks were used to demonstrate the applicability of the proposed method. In this paper, the performance of the proposed leak detection and identification methodology was evaluated using experiments with compressed air on a laboratory scale network. The on-line applicability of the proposed methodology was demonstrated through field level leak detection tests carried out on a 204.7 km long pipeline in India, supplying natural gas to a power plant. The laboratory and field tests demonstrated that the proposed methodology can be used for quick on-line detection of leaks, and locating the leaks reasonably accurately.     

Effect of pour point depressant on wax deposition and drag reduction in horizontal pipelines

A newly synthesized pour point depressant (PPD) was used to decrease the wax deposition thickness and drag force during a waxy crude oil flow in two horizontal pipes of length 2.5 m each and inner diameters 1 inch and 2 inches. The flow rates of 80–120 LPM were used. 1,000-ppm PPD reduced the thickness of wax deposited by 31% and 72% at 120 LPM and 30°C in 1-inch and 2-inch pipes, respectively. There was about 15% drag reduction in both the pipes at 30°C and 120-LPM flow rate after adding 1,000-ppm PPD.     

Accurate Cluster Head Selection Technique for Software Defined Network in 5G VANET

Wireless Personal Communications - The vehicular Ad Hoc Network is a very dynamic network with uncertain presence of vehicles on the road and data transmission between vehicles and road-side units....     

A critical review on lead-free hybrid materials for next generation piezoelectric energy harvesting and conversion

This article aims to provide a comprehensive review of lead-free hybrid nano materials based piezoelectric fillers. It narrates the basic concept of piezoelectricity and discusses the salient properties of piezoelectric materials. Piezoelectric materials divided into classes of ceramics (lead based and lead free), polymers and composites, have been discussed in detail. The potential environmental threat posed by lead (Pb) in the lead based piezoelectric materials have gradually shifted the focus to lead free piezoelectric materials. Hence, lead free piezoelectric materials have been the main focus of this review. Lead free hybrid fillers, to enhance the piezoelectric properties of composites, have been covered as an integral part of this review. This topic has been covered principally under headings of KNN based fillers, Bi based fillers, Ba based fillers and MoS₂ based fillers. The effect of doping into piezoelectric fillers have also been discussed in detail. With piezoelectricity being used in different fields of applications, a part of this review elucidates the use of piezoelectric materials to cater to the needs of technology. A brief overview has been provided regarding the use of piezoelectric materials in energy harvesting, as sensor, actuators, transducers, in structural health monitoring and repair, and in biomedical applications. The future scope of piezoelectricity and piezoelectric materials in fulfilling the demands of technology has been discussed in the concluding part of the review.     

Age-structured predator–prey model with habitat complexity: oscillations and control

In this article, we study a predator–prey interaction in a homogeneously complex habitat where predator takes a fixed time to develop from immature to its mature stage. The age-structure of the predator and its interaction with the prey is framed in a system of delay differential equations. The objective is to study the role of habitat complexity and the maturation delay of the predator on the overall dynamics of the model system. Different interesting dynamical behaviours can be obtained by regulating two key parameters, namely the degree of habitat complexity and the maturation delay. It is observed that the system becomes unstable from its stable condition when the maturation delay crosses some critical value. The periodic solutions bifurcated from the interior equilibrium is found to be supercritical and stable. Synchronization of population fluctuations is, however, possible by increasing the strength of habitat complexity. The predator population goes to extinction and the prey population reaches to its maximum, irrespective of the length of maturation delay, when the habitat complexity crosses some upper critical value. The qualitative dynamical behaviours of the model system are verified with the data of Paramecium aurelia (prey) and Didinium nasutum (predator) interaction.