Multi-Valued Performance Metrics for Real-Time Embedded Systems

To rapidly explore the design space of a real-time embedded system, it is essential to be able to efficiently analyze the timing behaviors of different system architectures. This includes not only determining if a design can satisfy all the timing constraints but also comparing the timing performance of different designs for tradeoff purposes. Understanding the exact timing behavior of a large system can be computationally prohibitive. Previous work in this area has mostly focused on producing a yes/no answer to the schedulability of a system architecture under the worst-case scenario. This not only often leads to overly pessimistic designs, but also provides no insight as how to rank different architectural designs with respect to their timing performance. In this paper, we present several metrics that may be used to measure the timing performance of a design. The metrics were analyzed using workloads from both real-world task systems and randomly generated task systems. A superior metric has been identified through analysis of large sets of experiments. We also show, through an example, how this metric can be used effectively during a design exploration process.     

A 0D Lead‐Free Hybrid Crystal with Ultralow Thermal Conductivity

Organic–inorganic hybrid materials are of significant interest owing to their diverse applications ranging from photovoltaics and electronics to catalysis. Control over the organic and inorganic components offers flexibility through tuning their chemical and physical properties. Herein, it is reported that a new organic–inorganic hybrid, [Mn(C₂H₆OS)₆]I₄, with linear tetraiodide anions exhibit an ultralow thermal conductivity of 0.15 ± 0.01 W m^?1 K^?1 at room temperature, which is among the lowest values reported for organic–inorganic hybrid materials. Interestingly, the hybrid compound has a unique 0D structure, which extends into 3D supramolecular frameworks through nonclassical hydrogen bonding. Phonon band structure calculations reveal that low group velocities and localization of vibrational energy underlie the observed ultralow thermal conductivity, which could serve as a general principle to design novel thermal management materials.     

Role of Drying Techniques on the Development of Porosity in Silica Gels

Silica gel has been prepared by the hydrolysis of TEOS under three different pH conditions. These gels have been subjected to drying in an air oven, under humidity, and also by exposure to microwaves, followed by further calcination at 500°C under slow heating schedule (3°C/min). Silica samples thus obtained are characterised by B.E.T. specific surface area and pore volume data. The thermal decomposition behaviour of the precursor gels are also reported. The adsorption isotherms of these samples indicate different behaviour related to the method of synthesis. Increase in pH of hydrolysis of the TEOS from 3 to 8 results in increase in specific surface area in tune with the earlier reports. However more significant observation is the variation in pore size distribution as evidenced from adsorption isotherms related to method of drying. Silica gels prepared at pH 3 show Type I behaviour irrespective of the method of drying. However gel prepared at pH 6 shows Type II behaviour when dried under microwave with specific surface area as high as 635 m₂/g and pore volume 0.9733 cc/g. The precursor gels prepared at still higher pH exhibit Type IV behaviour when subjected to microwave drying. The pH conditions of synthesis of precursor gels along with drying techniques appear to affect not only the surface areas and porosities but also the resultant adsorption isotherms, in sol-gel silica.     

Mechanical Properties and Microstructural Characteristics of Friction Welded Dissimilar Joints of Aluminium Alloys

Joining of similar and dissimilar combinations of aluminium alloys 2024 and 6061 were performed using friction welding technique. Microstructure, hardness and tensile properties of the joints were characterized. Microstructure of the alloy were found to change significantly across the joint such as fully deformed, partially deformed and undeformed regions due to deformation, frictional heat and alloy characteristics. Extensive fine grain size was observed in the fully deformed region and volume fraction of finer grains was higher in the alloy 2024 as compared to alloy 6061. Hardness was lower in the weld interface region of the similar joints of AA2024 and AA6061. The lower hardness in the dissimilar metal joint was observed in the heat affected zone of alloy 6061. The tensile strengths of the similar joints were 80 and 85% of respective base metal of alloys 2024 and 6061. The strength of the dissimilar metal joint was observed to be similar to the base metal strength of 6061 alloy. Tensile fracture occurred in the region of joints where lower hardness was observed. The maximum elongation were obtained in dissimilar joints of alloys and characterized by scanning electron microscope. It revealed deep dimple patterns unlike what was observed in similar joints.     

Palladium‐Catalyzed and Hybrid Acids‐Assisted Synthesis of [60]Fulleroazepines in One Pot under Mild Conditions: Annulation of N‐Sulfonyl‐2‐aminobiaryls with [60]Fullerene through Sequential C‐H Bond Activation,C‐C and C‐N Bond Formation

An extraordinarily efficient hybrid acids‐assisted, palladium‐catalyzed and chelating‐group‐assisted C H bond activation of N‐sulfonyl‐2‐aminobiaryls and their annulations with [60]fullerene via sequential C C and C N bond formation at room temperature to afford [60]fulleroazepines is demonstrated. The formation of [60]fulleroazepines is highly regioselective and tolerant to both electron‐withdrawing and electron‐donating groups on the aryl moiety and the reaction gives monofunctionalized fullerenes in good yields (up to 54% isolated yield and 92% based on converted C₆₀).     

Application of ultrasonic vibration assisted MQL in grinding of Ti–6Al–4V

This work presents experimental investigations performed to evaluate the improvement in grinding performance of Ti–6Al–4V alloy using ultrasonic vibration assisted minimum quantity lubrication (UMQL) technique. The grinding experiments have been performed using an indigenously designed and fabricated UMQL setup. In UMQL, the ultrasonic vibration of the horn has been used to atomise the cutting fluid into ultra-fine droplets of uniform size. Sunflower oil in 1, 5 and 10% of the volume have been added in water to prepare the biodegradable emulsions and used as grinding medium. The grinding performance during UMQL has been evaluated by comparing the grinding forces, surface roughness and the ground surface topography obtained during dry and conventional MQL (CMQL) techniques. Surface quality and chip morphology have been studied using microscopic imaging techniques. The UMQL grinding results in smaller grinding forces, and improved surface quality as compared to CMQL grinding. The experimental findings demonstrate that the UMQL has a strong potential to enhance the grindability of Ti–6Al–4V. The present work is also a step forward in finding a sustainable grinding technique for high strength materials using vegetable oil as a coolant.     

Room temperature synthesis of rutile TiO2 hierarchical nanoneedle flower morphology for dye sensitized solar cell

Rutile TiO2 nanoneedle flowers (representing concurrent nano-micro hierarchical morphology) with high shape anisotropy ratio are synthesized at room temperature by using a simple and efficient one step electrochemical process of anodic dissolution. This process employs highly acidic bath of perchloric acid (pH <2) and a large current density on the surface of Titanium foil to form nanostructures. The diameter and length of rutile TiO2 nanoneedle is approximately 8 nm and 100 nm respectively (aspect ratio >10). Dye sensitized solar cell (DSSC) configured using such rutile TiO2 flowers is shown to exhibit IPCE of 30% and power conversion efficiency of approximately 3.6%.     

An Improved Multi-Objective Particle Swarm Optimization Routing on MANET

A Mobile Ad hoc Network (MANET) is a group of low-power consumption of wireless mobile nodes that configure a wireless network without the assistance of any existing infrastructure/centralized organization. The primary aim of MANETs is to extend flexibility into the self-directed, mobile, and wireless domain, in which a cluster of autonomous nodes forms a MANET routing system. An Intrusion Detection System (IDS) is a tool that examines a network for malicious behavior/policy violations. A network monitoring system is often used to report/gather any suspicious attacks/violations. An IDS is a software program or hardware system that monitors network/security traffic for malicious attacks, sending out alerts whenever it detects malicious nodes. The impact of Dynamic Source Routing (DSR) in MANETs challenging blackhole attack is investigated in this research article. The Cluster Trust Adaptive Acknowledgement (CTAA) method is used to identify unauthorised and malfunctioning nodes in a MANET environment. MANET system is active and provides successful delivery of a data packet, which implements Kalman Filters (KF) to anticipate node trustworthiness. Furthermore, KF is used to eliminate synchronisation errors that arise during the sending and receiving data. In order to provide an energy-efficient solution and to minimize network traffic, route optimization in MANET by using Multi-Objective Particle Swarm Optimization (MOPSO) technique to determine the optimal number of clustered MANET along with energy dissipation in nodes. According to the research findings, the proposed CTAA-MPSO achieves a Packet Delivery Ratio (PDR) of 3.3%. In MANET, the PDR of CTAA-MPSO improves CTAA-PSO by 3.5% at 30% malware.     

Pre-treatment effect on the nutritional and functional properties of selected cassava-based composite flours

The low protein and lack of gluten in cassava (Manihot esculenta Crantz) are disadvantageous for its use for product development and is overcome through the use of composite flours incorporating cereal and/or legume flours. The functionality and nutritional attributes of cassava flour were altered in the present study by pre-treatment with termamyl and green gram amylase, pre-gelatinization and subsequent blending with cereals, legumes, bran sources etc. Malting of cassava flour with termamyl followed by pre-gelatinization reduced the starch and increased the sugar content of the mixes. Pre-gelatinization had little effect on the crude protein of the mixes; nevertheless, the fat content was higher by 0.15–1.0 units. Energy content was around 1176 and 1217 KJ/100 g for the rice bran added mixes from malted cassava, which slightly increased in the respective pre-gelatinized cassava mixes. The peak viscosity of termamyl treated cassava-based flour mixes was much lower than the respective gram amylase based mixes, indicating that the latter had much less amylolytic activity than termamyl and pre-gelatinization further reduced the viscosity. The very low viscosity for the enzyme treated cassava-based mixes was due to the inability for retrogradation of the hydrolyzed starch. Significant improvement in in vitro starch digestibility (IVSD) (enhancement by 5.0–16.0 units in termamyl treatment vs 5.0–9.0 units in gram amylase treatment) was observed for the pre-gelatinized mixes. Lowest IVSD (25–29 units) was for the two bran based mixes, suggesting its use in the nutrition therapy for controlling obesity linked diseases.

Industrial relevance

With the development in human society, the incidence of chronic diseases like diabetes, cancer, cardiovascular problems and conditions like obesity contributing to several diseases is on the increase. This has led to an increasing awareness and research efforts on the development of functional foods, pharmafoods etc, which have wide potential application in medical nutrition therapy. The present work aims at improving the nutritional and functional attributes of cassava through fortification with cereal and/ or legume flours, bran sources etc. and through pre- treatment with enzymes to improve the functionality and reduce the energy content. The study led to the development of cassava based composite flours with low starch digestibility, high protein content and low energy content which could be effectively utilized for developing designer foods for obese and diabetic people. Enhanced digestibility of pre- gelatinized malted flours from cassava finds potential application for the development of foods for geriatric and convalescent people.     

Phytochemical constituents of fucoidan (Padina tetrastromatica) and its assisted AgNPs for enhanced antibacterial activity

Biological synthesis of nanomaterials is a growing innovative approach and it was broadly utilised in the field of nanotechnology and nanomedicine. This study illustrates that biosynthesis of silver nanoparticles (AgNPs) using fucoidan extracted from seaweed Padina tetrastromatica. The functional groups of extracted fucoidan were characterised by Fourier transform infrared spectroscopy (FTIR) and used to NPs synthesis. Synthesised AgNPs were characterised by ultraviolet–visible spectra, scanning electron microscope, energy dispersive X‐ray, transmission electron microscope, selected area electron diffraction and FTIR. In this study, their main focus is enhancement antibacterial activity of AgNPs coated antibiotics against antibiotic resistant bacteria. Among the microorganisms, Serratia nematodiphila was resistant to novobiocin and penicillin, but it was sensitive to AgNPs impregnated antibiotic discs. The zone of inhibition was 12 and 15 mm. The synergistic effect of combined antibiotics and AgNPs resulted in increased fold area which was greater than the sum of their separate effects. It reveals that AgNPs are highly sought in the medicinal field due to their broad spectrum of antibacterial activity and relatively cheaper. This enhanced synergistic effect potentially superior to control the growth of bacteria and it is the budding process for the development of new remedial agents for severe diseases.Inspec keywords: silver, nanoparticles, nanomedicine, antibacterial activity, drug delivery systems, Fourier transform infrared spectra, ultraviolet spectra, visible spectra, scanning electron microscopy, X‐ray chemical analysis, transmission electron microscopy, electron diffraction, microorganisms, diseases, nanofabrication, drugs, cellular biophysicsOther keywords: phytochemical constituents, enhanced antibacterial activity, nanotechnology, nanomedicine, drug delivery, silver nanoparticles, biosynthesis, fucoidan extraction, marine brown seaweed Padina tetrastromatica, functional groups, Fourier transform infrared spectroscopy, FTIR spectroscopy, ultraviolet‐visible spectra, scanning electron microscopy, energy dispersive X‐ray analysis, transmission electron microscopy, selected area electron diffraction, AgNP coated antibiotics, antibiotic resistant bacteria, Serratia nematodiphila, novobiocin, penicillin, AgNP impregnated antibiotic discs, medicinal field, broad spectrum, enhanced synergistic effect, diseases, Ag