Search

Container-based virtualization has gained significant popularity in recent years because of its simplicity in deployment and adaptability in terms of cloud resource provisioning. Containerization technology is the recent development in cloud computing systems that is more efficient, reliable, and has better overall performance than a traditional virtual machine (VM) based technology. Containerized clouds produce better performance by maximizing host-level resource utilization and using a load-balancing technique. To this end, this article concentrates on distributing the workload among all available servers evenly. In this paper, we propose a Grey Wolf Optimization (GWO) based Simulated Annealing approach to counter the problem of load balancing in the containerized cloud that also considers the deadline miss rate. We have compared our results with the Genetic and Particle Swarm Optimization algorithm and evaluated the proposed algorithms by considering the parameter load variation and makespan. Our experimental result shows that, in most cases, more than 97% of the tasks were meeting their deadline and the Grey Wolf Optimization Algorithm with Simulated Annealing (GWO-SA) performs better than all other approaches in terms of load variation and makespan.

Smart healthcare is a healthcare delivery system that leverages wearable devices, the internet of things, and the mobile internet to access information dynamically, connect people, materials, and institutions in the healthcare industry, and then intelligently control and respond to medical ecosystem demands. The internet of medical things(IoMT) plays an essential role in providing smart healthcare services to patients. In IoMT, several pieces of medical equipment are connected with each other and share data. On the other hand, cloud computing facilitates different computing services, including software, networking, data storage, servers, and data analytics over the internet. This chapter proposes an architecture to integrate cloud, edge, and internet of medical things. This architecture will facilitate remote patient monitoring, medical data analytics, and interoperability. Finally, we look ahead and evaluate the future prospects and challenges of smart healthcare.

We report the enhancement of microwave absorption properties in BaTiO3 ceramics induced by exposing under high energy gamma radiation at 5 kGy, 10 kGy and 15 kGy, gamma-ray doses in a properly shielded Co60 γ-radiation chamber. The tetragonality ratio (c/a) decreases with increasing gamma dose on powder samples together with the reduction of grain size from ~2 μm to ~0.5 μm. Further, the irradiated BaTiO3 powder based ceramic tiles are fabricated and electromagnetic (EM) measurements suggest increase in imaginary permittivity and loss tangent values (tanδe) at resonance frequency of ~8.8 GHz. Reflection loss (RL) plots of BT tiles showed enhancement in microwave loss at higher gamma radiation doses. As per the customized requirements, two type of extremely thin ceramic tiles are obtained viz. Resonating (RL> 40 dB at 9.6 GHz) and wide-band (RL> 8 dB over entire X-band) for their possible use for MW attenuation on different objects/platforms.

There has been a rapid development of healthcare systems in recent times. The main objective of the intelligent healthcare system is to manage, monitor intelligently, and respond to the requirement of the medical ecosystem. In a smart healthcare system, access to different healthcare services and delivery of those services are done by adopting various technologies. Information and communication technology (ICT) has greatly influenced today's healthcare system. The term smart healthcare system comes to the fore because of the integration and application of technologies such as the internet of medical things (IoMT), cloud computing, edge computing, containerization, big data, artificial intelligence, etc. In a smart healthcare system, several medical devices are equipped for collection and management of medical data, remote patient monitoring, tracking health status and location of patients, and monitoring and controlling medical devices to act according to the patients' suitability.

Thin flexible microwave absorbers are highlighted as current research focus not only for lightweight but also for their easy applicability on the surface of complex geometries. In order to achieve it, we prepared iron microflakes of planar size in the range of 5–15 $\mu \text{m}$ with the thickness of 1–2 $\mu \text{m}$ , and thereafter, silica coating has been provided on surface of flakes by utilizing modified Stobers method to improve the oxidation resistance. The silica coating on surface of iron microfalkes has been established through different techniques, namely, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Rubber-based composites are prepared at different Fe at SiO2 loading fractions [40–70 parts per hundred (PHR)] in nitrile butadiene rubber (NBR) and their electromagnetic properties are investigated. The 70 PHR Fe at SiO2/NBR composite showed more than 90% microwave absorption [reflection loss (RL) > 10 dB] over 10.5–16.5 GHz at absorber thickness of ~1.2 mm and also showed tunable RL of more than 10 dB with variation of thickness from 1 to 2.0 mm within 4–18 GHz. Furthermore, Fe at SiO2 microflakes exhibited better microwave-absorption performance in comparison to uncoated Fe microflakes in the rubber composite, which may be due to improved impedance matching.

Three highly discussed and researched computing technologies in recent times are cloud computing, edge computing, and the Internet of Things (IoT). In cloud computing, service seekers request computing resources from cloud servers connected over the Internet. In edge computing, the edge devices are placed between the cloud server and service seekers resulting in faster access to the computing resources and hence reducing the computational time and cost. Internet of Things is a technology where several devices are connected and communicate with each other over the Internet. In this paper, we try to integrate these three technologies and propose a cloud-edge centric Internet of Things architecture for service provisioning in a smart city. The integration of these technologies improves the overall performance of the smart city system by efficiently utilizing the computing resources resulting in reduced makespan, response time, and implementation cost, increased throughput, and better security of data.

This is the first study to comprehend copper (Cu)-dynamics in a monsoon fed Indian estuarine system (the Mandovi estuary from the central west coast of India). Distribution and speciation of Cu in estuarine sediment, pore water, suspended particulate matter (SPM) and water column was used to understand geochemical cycling of Cu in the estuary. Geochemical fractionation study reveals that sedimentary organic carbon (Corg) was the major hosting phase for non-residual Cu in the sediments. Experimental analysis and chemical speciation modelling suggests that leaching of sedimentary Cu2+, CuCO3 and a fraction of Cu-Corg complexes increased Cu-concentrations in the pore water towards the downstream of the estuary. Dissolved Cu concentration in overlying water column was observed to increase with increasing Cu concentrations in the pore water. This study suggests that chemical speciation of sedimentary Cu play key role in controlling its distribution and dynamics in the tropical estuarine system during dry period.

An energy efficient and scalable process has been developed for the preparation of intermetallic Fe–Si–Al alloy particles. The preparation process involves initial homogenization & mechanical activation of elemental metal powders followed by vacuum annealing at elevated temperature ~ 650 °C. The physical properties of the as synthesized powders were investigated by means of X-ray Diffraction (XRD), Energy Dispersive Xray Flourence (EDXRF),Vibration Sample Magnetometer (VSM), Scanning Electron Microscope (SEM) and Particle Size Analyser. Composite coatings have been prepared by dispersing 30–60 wt% of Fe–Si–Al alloy in polyurethane (PU) resin. The effect of loading of Fe–Si–Al alloy on dielectric and electromagnetic (EM) properties of composites are studied in 6–18 GHz. A suitable formulation (50 wt% Fe–Si–Al) has been identified, wherein, proper combination of dielectric and magnetic loss of coating composite showed optimal microwave (MW) absorption in 6–18 GHz. The identified composite coating of thickness ~ 1.6 mm showed maximum Return Loss (RL) value ~ − 43 dB at 11.9 GHz and the loss values can exceed more than 10 dB within 6.5 to 16 GHz while varying thickness of coating from 1.2 to 2.2 mm. In the present study, microwave absorption properties of coatings are mainly credited to dielectric and magnetic loss values of the composites. The Fe-Si-Al filled resin composite with optimal loading of alloy particles can be a promising candidate for microwave absorbing coating applications.

A lot of work has been done and extensive research is going on for reducing the energy consumption of large-scale cloud data centers along with the maximization of host level utilization. Because of on-demand service provisioning, the number of users’ requests increases which leads to an increase in the number of physical machines and data center size. This results in increased energy consumption in the data center as energy consumption is directly proportional to the number of the active physical machine. The container is a lightweight approach to operating system virtualization, offers an opportunity to improve the efficiency in cloud data centers. Containerized cloud gaining widespread popularity in recent years, so an efficient container consolidation is an open research challenge. Container consolidation is used to optimize energy consumption, as the resource utilization by the containers is directly relates to energy consumption. Container consolidation is an NP-Hard problem which can be solved by heuristic and metaheuristic algorithm. Therefore, in this paper, we implemented the heuristic and metaheuristic algorithm for energy reduction in the cloud. We implemented the next fit, best fit, best fit decreasing, first fit, first fit decreasing and compare their result. The experimental result shows that the best fit decreasing and first fit decreasing gave the almost same result. Further, this result is compared with the proposed Energy Efficient Genetic Algorithm(EEGA). We got the best result with the proposed EEGA.

On-demand provisioning of computing services such as analytics, intelligence, networking, storage, and servers, etc. over the internet is the main function of cloud computing. Several servers are connected in a distributed manner over the internet to execute tasks. Recently, container technology has gained enormous popularity as it can improve overall application performance by providing OS-level virtualization in cloud computing systems. Based on the resources available on server, a server can accommodate more than one container running on it. The process of distributing the incoming requests or user tasks among all available servers in such a way that all the servers will have almost equal workload is called load balancing. In this paper, we proposed a Grey Wolf Optimization(GWO) based technique for load distribution in the containerized cloud and also to reduce the makespan. We have compared our results with the Genetic algorithm and Particle Swarm Optimization(PSO) based algorithm. The experimental result indicate that the GWO based technique is performing better in terms of load balancing and also having reduced makespan.

Cloud computing is one of the highly discussed topics in the field of Internet and communication technology. It is responsible for the on-demand provision of computing resources, mainly data and computing power to the end-users. More than one server works together in a cloud network. So, the incoming request for resources must be distributed among all servers in the network for better performance. The process of efficiently distributing incoming tasks and sharing the workload among a group of servers is called load balancing. In this paper, we propose a randomized algorithm for load balancing in a containerized cloud. The approach we have used is called Balls into Bins via Local Search. In our algorithm, we have considered tasks as balls and servers as bins. First, we construct a fully connected undirected graph of nodes(server) and then convert it to a minimum edge weight graph to reduce the network cost. Our experimental result shows that the load is distributed among all servers almost equally. The difference between the highest and lowest workload in the network is minimized.

Cloud computing provides information technology based solutions to the end-users as a utility. Virtual machine or the virtualization technology is the backbone of implementing cloud computing technologies. However, such implementation encounters the problem of tremendous energy consumption. One of the foremost issues in implementing cloud computing is high energy consumption. This can be reduced to some extent by proper allocation and efficient utilization of resources. At present, containerization is one of the broadly discussed techniques as an alternative to traditional virtualization solutions. In this paper, we propose a game-theoretic approach for resource allocation and a containerized cloud architecture which drastically reduces energy consumption than a virtual machine based cloud. We have used Google cluster traces data set for our experiment in the cloud with virtual machine and containerized cloud. Experimental results show that the energy consumption is minimized in the containerized cloud than a cloud with virtual machines.

Cloud computing is one of the emerging technology in the field of distributed computing and is designed as per the requirement and demand of the user. It uses the virtualization technique to create multiple virtual machines that are the basis of computation in the cloud. One of the major issues in cloud computing is to efficiently schedule the tasks and completing their execution before the deadline to maximize the utilization of the processor, maximize the throughput and reduce the waiting time of the task. In this paper, first, we propose a system model and proposed a game-theoretic framework for scheduling realtime tasks in the cloud computing environment to reduce the total completion time and total waiting time. In our game model task act as a player, the virtual machine act as a strategy and the payoff of the player is represented by completion time and waiting time. We have performed our experiments using the non-cooperative and cooperative game model. Our experimental results show that the total execution time and total waiting time are less in the cooperative game model than a non-cooperative game model.

Herein, we reports the application of various spinel ferrite nanoparticles, MFe2O4 (M = Co, Ni, Cu, Zn), as efficient catalyst for Biginelli reaction. All ferrite nanoparticles were synthesized using a novel aqueous solution based method. It was observed that, the catalytic activity of the ferrite nanoparticles followed the decreasing order of CoFe2O4 > CuFe2O4 > NiFe2O4 > ZnFe2O4. The most important feature of these ferrite nanocatalysts is that, these nanoparticles can directly be used as catalyst and no surface modification or functionalization is required. These ferrite nanoparticles are easily separable from reaction mixture after reaction by using a magnet externally. Easy synthesis methodology, high catalytic activity, easy magnetic separation and good reusability make these ferrite nanoparticles attractive catalysts for Biginelli reaction.

Graphitic carbon-coated Ni metal core nanoparticles are synthesized using controlled thermal treatment of Ni-hydroxide in an aniline–formaldehyde copolymer matrix under a N2 atmosphere. The structural and microstructural studies substantiate the formation of a graphitic shell on the metallic nickel core. The 850 °C heat-treated core–shell structured material is ferromagnetic in nature with high saturation magnetization. The sample with the highest value of magnetic moment is impregnated in a rubber matrix to prepare composite samples with core–shell nanomaterials of different weight fractions. The sample with 70 wt% Ni/graphitic carbon core–shell powder in the elastomeric rubber matrix showed the optimal microwave absorption at a fairly low thickness of ∼1 mm. This is attributed to the optimized combination of the effective impedance matching and interfacial polarization losses. Further increase in the Ni/graphitic carbon filler material resulted in reduced microwave absorption due to the greater mismatch of impedance as compared to the desired free space impedance of ∼377 Ω. Thus, the optimized composite material is of great potential for microwave absorption in the Ku band.

W-type barium cobalt hexaferrites substituted with different concentrations of Mn2+, Zn2+ ions in Ba(MnZn)xCo2(1-x) F16O27 (x = 0.0, 0.3, 0.4, 0.5 and 0.7) have been prepared by simple and cost effective solid state process. From XRD analysis, the systematic incorporation of these ions into lattice of ferrite has been confirmed from gradual decrease in lattice parameters of its hexagonal structure. SEM analysis reveals the formation of distorted hexagonal platy morphology of these powders with particles size of 2–15 µm with thickness of 1–2 µm for x = 0.4. With an appropriate substitution of Mn2+, Zn2+ (x = 0.4), ferrite showed the highest saturation magnetization (Ms) and broad magnetic loss tangent (tan δm) > 0.8 over 6–18 GHz with maximum value ~ 1.4 at 15 GHz. To obtain flexible microwave absorber, Ba(MnZn)0.4Co1.2F16O27/NBR composites have been prepared with different loading percentage (50–80 wt%) of ferrite for investigation of microwave absorption properties. Composite with higher content of ferrite (NBR-F80) shows >90% microwave absorption (RL > 10 dB) over 7.5–14 GHz with maximum value of ~ –37 dB at 10.5 GHz at absorber thickness of ~ 2.5 mm. The maximum absorption and bandwidth (RL > 10 dB) of absorber can be tuned with variation of thickness from 2.0 to 3.0 mm within 6–18 GHz. The maximum absorption of the absorber is attributed to the presence of large content of ferrite and its hexagonal plate like morphology of particles, which enhances multiple scattering within material. The fabricated flexible rubber based MW absorbers may be a potential candidates for wide band frequency applications on any target with complex geometry.

Here, we report a facile hydrothermal synthesis method to prepare BiFeO3 nanowire-reduced graphene oxide (BFO-RGO) nanocomposites. The unique properties of 2-D reduced graphene oxide (RGO) and 1-D BiFeO3 nanowires (BFO) were exploited to design nanocomposites to obtain high performing microwave absorber materials. The composite with 97 wt % BFO and 3 wt % RGO exhibited minimum reflection loss value of −28.68 dB at 10.68 GHz along with the effective absorption bandwidth (≥ −10 dB) ranging from 9.6 to 11.7 GHz when the absorber thickness was only 1.55 mm. First-principles calculations based on density functional theory (DFT) of BFO, graphene, and BFO-RGO nanocomposites were performed to obtain information about their electronic structures to interpret their complex permittivity and its derived properties. To the best of our knowledge, this is the first time investigations on microwave absorption properties of the BiFeO3 nanowire and BFO-RGO nanocomposites have been reported, and this nanocomposite shows its...

Here, synthesis and catalytic activity of a novel nanocatalyst (CuO@mTiO2@CF), consisting of CuO nanoparticles, mesoporous titanium oxide and Cobalt ferrite have been reported for the first time. The catalyst was synthesized using a simple aqueous solution based chemical methodology. Synthesized CuO@mTiO2@CF showed excellent catalytic activity towards various organic reactions such as (i) Epoxidation of styrene, (ii) Click reaction, (iii) Biginelli reaction, (iv) Reduction of 4-Nitrophenol and trifluralin in presence of excess NaBH4. Moreover, this novel nanocatalyst offered easy magnetic separation after the catalysis reaction and excellent reusability. Easy synthesis methodology, versatility, good reusability and easy separation make the nanocatalyst attractive in the field of heterogeneous catalysis.

We report the synthesis of Ti-Si-C system with MAX-phase (Ti3SiC2) by Mechanically Activated Self-propagating High-temperature Synthesis (MASHS) and preparation of their composite powders with Al2O3 in different weight fractions. In the subsequent step, the composite powders were converted into granules with desired fluidity for gas flame spraying. An in-house designed and developed Thermal Spray Coating apparatus was used in the gas flame spray process to coat the prepared composite powder granules on to Ti alloy substrate. XRD studies reveal formation of MAX-phase Ti3SiC2 primarily and SEM analysis suggests grains of layered morphology that consist of thin lamellar structures of thickness 90–130 nm. During gas flame spraying, Ti3SiC2 decomposes into TiC and their concentrations present in composites consequently influence the electromagnetic (EM) properties of the coating. Based on the EM studies, a suitable ceramic composition has been identified (Al2O3/50wt%Ti-Si-C) that offers better frequency dispersion of permittivity, with broader bandwidth of microwave absorption over 8.2–12.4 GHz. The optimized composite coating of thickness ~1.8 mm shows more than 90% microwave absorption [Reflection Loss (RL) > 10 dB] over 8.3–12.4 GHz with maximum value ~−37 dB at 9.7 GHz. In present investigation, onset of microwave absorbing properties of coating are attributed to interfacial polarization and conduction loss arises due to the presence of TiC and resistive phase Ti3SiC2 in the composite. The Al2O3/Ti-Si-C composites with optimal MAX phase Ti3SiC2 content can be a promising candidate for microwave absorbing stealth applications.

Tetragonal BaTiO3 bulk samples are prepared using the solid-state route in conjunction with intermediate high-temperature annealing steps. The (002) and (200) X-ray diffraction peaks near 2Ɵ~45° and 310, 520, and 720 cm−1 characteristic vibrational modes in Raman spectroscopic measurements confirm the tetragonal crystallographic structure of BaTIO3 bulk samples. The 1100°C annealed BaTiO3 sample showed optimal tetragonality ~1.016 and the same is used for BaTiO3–acrylonitrile butadiene rubber (NBR) composites at different BaTiO3 loading fractions in parts per hundred (PHR). These BaTiO3/NBR composite systems exhibit dual band microwave resonance, widening the operating window for microwave absorption applications. Eighty PHR BaTiO3/NBR composite exhibits microwave reflection losses (RL) at 9.5 and 16.5 GHz with ~−9 and ~−18 dB reflection losses, respectively. The onset of dual band is attributed to the ferroelectric-induced dipolar relaxation at 9.5 GHz and its second-order resonance at 16.5 GHz in such composite systems.

Here, an ‘in situ’ co-precipitation reaction method has been reported for the preparation of CoFe2O4–RGO (CF–RGO) nanocomposites. To the best of our knowledge, this is the first time a simple synthetic method is reported for the preparation of CoFe2O4–RGO nanocomposites where a hydrothermal technique was not used. The novelty of this technique lies in its simplicity, cost-effectiveness, and the capability of large scale production of CoFe2O4–RGO nanocomposites. The synthesized CoFe2O4–RGO nanocomposites possess excellent microwave absorbing properties as well as high photocatalytic activity towards the degradation of various dyes under visible light irradiation. 85CF–15RGO (85 wt% CF and 15 wt% RGO) showed excellent microwave absorption properties with a Reflection Loss (RL) of −31.31 dB (∼99.94% absorption) at 9.05 GHz with an 8.2–10.92 GHz effective band width range. To the best of our knowledge 85CF–15RGO nanocomposite exhibited comparable and even superior microwave absorption properties in the X-band region than most of the ferrite based composites. 75CF–25RGO (75 wt% CF and 25 wt% RGO) acted as a very good magnetically separable photocatalyst for the degradation of various synthetic dyes (such as methyl orange, methylene blue, rhodamine B and a mixture of these dyes) under visible light irradiation emitted from a 100 W reading lamp. Moreover, CoFe2O4–RGO catalyst also showed easy magnetic separation with high reusability. The photocatalytic activity of 75CF–25RGO was found to be comparable and in some cases better than the various reported RGO–ferrite composites. The simple method of preparation and multifunctional character make CF–RGO nanocomposites attractive materials for application in the area of photocatalysis as well as microwave absorption.

A Ni0.8Zn0.2Fe2O4 reduced graphene oxide nanocomposite has been synthesized by a simple ‘in situ co-precipitation’ technique. This composite exhibited an ability to act as an excellent magnetically separable catalyst towards the degradation of various dyes as well as a toxic herbicide (trifluralin). It also demonstrated very good microwave absorption properties.

We designed an experimental set-up and optimized the process parameters for large scale synthesis (250 g) of low density nickel core metal with graphitic carbon shell as functional nanomaterial with highly reproducible physical properties. Structural characterization reveals formation of nano-core FCC Ni metal ~40 nm with ~7 nm thick graphitic shell after annealing at 850 °C. Room temperature field dependent magnetic (M−H) measurement reveals significant saturation magnetization in the sample even with non-magnetic graphite shell. The structural and magnetic properties are compared with small-scale batch synthesis (10 g), reported earlier. The temperature-dependent magnetic measurements suggest that Ni/graphite core-shell samples, annealed at 550 °C, and 700 °C are superparamagnetic, whereas sample annealed at 850 °C is ferromagnetic. The developed synthesis set-up is simple, environment friendly, and cost-effective. Further, to cater the end use applications of such materials for industrial, bio-medical and microwave absorption, the reported method may be further scaled up for large production.

article i nfo Hard soft ferrite nanocomposites One-pot synthesis Spring exchange coupling Magnetic measurements Microwave absorption In this paper, we report a simple but novel aqueous solution based 'one-pot' method for preparation of (Ni0.65Zn0.35Fe2O4)x-(BaFe12O19)1 � x nanocomposites consisting of hard ferrite-soft ferrite phases. Nanocom- posites, having same compositions, have also been prepared by employing a physical mixing method. X-ray dif- fraction analysis showed the presence of nanocrystalline Ni0.65Zn0.35Fe2O4 and BaFe12O19 phases in the composites, prepared by both methods. However, transmission electron microscopic and scanning electron mi- croscopic analysis revealed that, nanocomposites, prepared by one-pot method, possessed better homogeneous

CoFe2O4 nanoparticles, synthesized via a co-precipitation method at 120 °C, exhibited excellent microwave absorption properties, with minimum reflection loss of −55 dB (∼99.99%) at 9.25 GHz. To the best of our knowledge, these synthesized CoFe2O4 nanoparticles show the highest minimum reflection loss in comparison with the reported CoFe2O4 based materials.

This study deals with the exploration of CoFe2O4 supported Ag nanoparticles as a catalyst for the decolorization of various dyes (such as 4-nitrophenol, Congo red, rhodamine B) and dye mixtures by employing a reduction reaction with excess NaBH4 in an aqueous medium. Nanocatalysts with 10 wt% Ag loading (10Ag@CoFe2O4) exhibited very high catalytic activity and dye solutions were found to be decolorized within 4 to 6 minutes. A simple method for the preparation of a catalyst (10Ag@CoFe2O4) was reported, which exhibited very high catalytic efficiency towards the decolorization of dyes with different chemical structures as well as demonstrating its magnetic properties for easy separation from reaction mixtures and its reusability.

Nanostructured multiferroic BiFeO3 powder has been synthesized using sol–gel route followed by optimized post-annealing treatment. The phase pure rhombohedral structure of prepared powder was confirmed by X-ray diffraction and Fourier transform infrared studies. The room temperature weak ferromagnetic nature (~ 0.15 emu/g) exhibited by the nanocrystalline BiFeO3 sample (~ 50 nm) is attributed to the canted spin ordering in the sample. The BiFeO3/NBR rubber composites, with 50–80 wt% filler loading fractions, show the dual band resonating microwave (MW) absorption behavior. The reflection loss (R.L.) values enhanced and required absorber thickness reduced simultaneously with increasing BiFeO3 loading fraction in composite samples. These results confirm that the ferroelectric properties of multiferroic BiFeO3 are contributing significantly for the observed MW absorption with respect to the magnetic contribution.

The gel to carbonate precipitate route has been used for the synthesis of Ni1−xZnxFe2O4 (x = 0, 0.25, 0.5 and 0.75) bulk inverse spinel ferrite powder samples. The optimal zinc (50%) substitution has shown the maximum saturation magnetic moment and resulted into the maximum magnetic loss tangent (tanδm) > −1.2 over the entire 2–10 GHz frequency range with an optimum value ~−1.75 at 6 GHz. Ni0.5Zn0.5Fe2O4- Acrylo-Nitrile Butadiene Rubber (NBR) composite samples are prepared at different weight percentage (wt%) of ferrite loading fractions in rubber for microwave absorption evaluation. The 80 wt% loaded Ni0.5Zn0.5Fe2O4/NBR composite (FMAR80) sample has shown two reflection loss (RL) peaks at 5 and 10 GHz. Interestingly, a single peak at 10 GHz for 3.25 mm thickness, can be scaled down to 5 GHz by increasing the thickness up to 4.6 mm. The onset of such twin matching frequencies in FMAR80 composite sample is attributed to the spin resonance relaxation at ~5 GHz (fm1) and destructive interference at λm/4 matched thickness near ~10 GHz (fm2) in these composite systems. These studies suggest the potential of tuning the twin frequencies in Ni0.5Zn0.5Fe2O4/NBR composite samples for possible microwave absorption applications.

In this paper, a distributed architecture for the implementation of smart city has been proposed to facilitate various smart features like solid waste management, efficient urban mobility and public transport, smart parking, robust IT connectivity, safety and security of citizens and a roadmap for achieving it. How massive volume of IoT data can be analyzed and a layered architecture of IoT is explained. Why data integration is important for analyzing and processing of data collected by the different smart devices like sensors, actuators and RFIDs is discussed. The wireless sensor network can be used to sense the data from various locations but there has to be more to it than stuffing sensors everywhere for everything. Why only the sensor is not sufficient for data collection and how human beings can be used to collect data is explained. There is some communication protocols between the volunteers engaged in collecting data to restrict the sharing of data and ensure that the target area is covered with minimum numbers of volunteers. Every volunteer should cover some predefined area to collect data. Then the proposed architecture model is having one central server to store all data in a centralized server. The data processing and the processing of query being made by the user is taking place in centralized server.

The development of a simple yet novel aqueous solution based ‘one-pot’ method has been reported for the preparation of nanocomposites composed of soft ferrite (Mn0.2Ni0.4Zn0.4Fe2O4) and hard ferrite (BaFe12O19) phases. A physical mixing method has also been employed to prepare nanocomposites having the same compositions. The effects of synthetic methodologies on the microstructures of the nanocomposites as well as their magnetic and microwave absorption properties have been evaluated. The crystal structures and microstructures of these composites have been investigated using X-ray diffraction, transmission electron microscopy and scanning electron microscopy. In the nanocomposites prepared by both methods, the presence of nanocrystalline Mn0.2Ni0.4Zn0.4Fe2O4 and BaFe12O19 phases were detected. However, nanocomposites prepared by the one-pot method possessed better homogeneous distribution of hard and soft ferrite phases than the nanocomposites prepared by the physical mixing method. Very good spring exchange coupling interaction between the hard and soft ferrite phases was observed for the nanocomposites prepared by the one-pot method and these composites exhibited magnetically single phase behaviour. The spring exchange coupling interaction enhanced the magnetic properties (high saturation magnetization and coercivity) and microwave absorption properties of the nanocomposites prepared by the one-pot method, in comparison with the nanocomposites prepared by the physical mixing method as well as pure Mn0.2Ni0.4Zn0.4Fe2O4 and BaFe12O19 nanoparticles. The minimum reflection loss of the composites was found to be ∼−25 dB (i.e. >99% absorption) at 8.2 GHz with an absorber thickness of 3.5 mm.

Two different kinds of CuO nanoparticles (NPs) namely CuO nanorods (PS2) and multi-armed nanoparticles (P5) were synthesized by wet and electrochemical routes, respectively. Their structure, morphology, size and compositions were characterized by SEM, EDX and XRD. The NPs demonstrated strong bactericidal potential against Bacillus anthracis cells and endospores. PS2 killed 92.17% of 4.5 × 104 CFU/mL B. anthracis cells within 1 h at a dose of 1 mg/mL. Whereas P5 showed a higher efficacy by killing 99.92% of 7 × 105 CFU/mL B. anthracis cells within 30 min at a dose of 0.5 mg/mL and 99.6% of 1.25 × 104 CFU/mL B. anthracis cells within 5 min at a dose of 2 mg/mL. More than 99% of spores were killed within 8 h with 2 mg/mL PS2 in LB media.

A simple method for the preparation of magnetic nanocomposites consisting of NiFe2O4 nanoparticles, polybenzoxazine (PB), linear low-density polyethylene (LLDPE) and LLDPE-g- Maleic anhydride (LgM) is described. Composites were prepared by forming benzoxazine- NiFe2O4 nanocomposites followed by melt blending with LLDPE and thermal curing of benzoxazine. The composites were characterized by XRD, DSC and TGA, FT-IR, SEM, UTM and VSM. The saturation magnetization of the composites containing 33.25 wt% NiFe2O4 was 7.72 emu/g and it decreased with decreasing amount of NiFe2O4 in the composite. The composite films exhibited mechanical flexibility as well as magnetic properties.

Evolutionary algorithms are becoming an important aspect of artificial intelligence and are successfully applied to a variety of optimization problems. This paper presents genetic algorithm and quadratic programming concepts in solving economic load dispatch in which the total cost of generating power is minimized with a valve point loading effect while satisfying the load demand irrespective of transmission line losses. This work aims in modeling the economic load dispatch problem with transmission loss and is being applied to the test systems i.e. IEEE 14 BUS and IEEE 30 BUS using MATLAB.

The physical and chemical properties of the nanoparticles influence their pharmacokinetics and ability to accumulate in tumors. In this paper we report a facile method to conjugate folic acid molecule to iron oxide nanoparticles to increase the specific uptake of these nanoparticles by the tumor, which will be useful in targeted imaging of the tumor. The iron oxide nanoparticles were synthesized by alkaline co precipitation method and were surface modified with dextranto make them stable. The folic acid is conjugated to the dextran modified iron oxide nanoparticles by reductive amination process after the oxidation of the dextran with periodate. The synthesized folic acid conjugated nanoparticles were characterized for size, phase, morphology and magnetization by using various physicochemical characterization techniques such as transmission electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy, vibrating sample magnetometry, dynamic light scattering and zetasizer etc. The quantification of the generated carbonyl groups and folic acid conjugated to the surface of the magnetic nanoparticles was done by colorimetric estimations using UV-Visible spectroscopy. The in vitro MR studies were carried out over a range of concentrations and showed significant shortening of the transverse relaxation rate, showing the ability of the nanoconjugate to act as an efficient probe for MR imaging. The biodistribution studies and the scintigraphy done by radiolabeling the nanoconjugate with 99mTc show the enhanced uptake at the tumor site showing its enhanced specificity.

The gel to carbonate precipitate route has been used for the synthesis of Ni1−xZnxFe2O4 (x = 0, 0.25, 0.5 and 0.75) bulk inverse spinel ferrite powder samples. The optimal zinc (50%) substitution has shown the maximum saturation magnetic moment and resulted into the maximum magnetic loss tangent (tanδm) > −1.2 over the entire 2–10 GHz frequency range with an optimum value ~−1.75 at 6 GHz. Ni0.5Zn0.5Fe2O4- Acrylo-Nitrile Butadiene Rubber (NBR) composite samples are prepared at different weight percentage (wt%) of ferrite loading fractions in rubber for microwave absorption evaluation. The 80 wt% loaded Ni0.5Zn0.5Fe2O4/NBR composite (FMAR80) sample has shown two reflection loss (RL) peaks at 5 and 10 GHz. Interestingly, a single peak at 10 GHz for 3.25 mm thickness, can be scaled down to 5 GHz by increasing the thickness up to 4.6 mm. The onset of such twin matching frequencies in FMAR80 composite sample is attributed to the spin resonance relaxation at ~5 GHz (fm1) and destructive interference at λm/4 matched thickness near ~10 GHz (fm2) in these composite systems. These studies suggest the potential of tuning the twin frequencies in Ni0.5Zn0.5Fe2O4/NBR composite samples for possible microwave absorption applications.

A simple method for the preparation of magnetic nanocomposites consisting of cobalt ferrite (CF; CoFe2O4) nanoparticles, polybenzoxazine (PB), linear low-density polyethylene (LLDPE), and linear low-density polyethylene-g-maleic anhydride (LgM) is described. The composites were prepared by the formation of benzoxazine (BA)–CF nanopowders followed by melt blending with LLDPE and the thermal curing of BA. The composites were characterized by X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, universal testing machine measurement, and vibrating sample magnetometry. The composites consisting of LLDPE, PB, and LgM (47.5L–47.5PB–5LgM) exhibited a higher tensile strength (23.82 MPa) than pure LLDPE and a greater elongation at break (6.11%) than pure PB. The tensile strength of the composites decreased from 19.92 to 18.55 MPa with increasing CF loading (from 14.25 to 33.25 wt %). The saturation magnetization of the composites containing 33.25 wt % CF was 18.28 emu/g, and it decreased with decreasing amount of CF in the composite. The composite films exhibited mechanical flexibility and magnetic properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Eu 3+ doped Y 2 O 3 nanophosphors have been synthesized using the simple colloidal precipitation method. Doping of Eu 3+ ions in host yttria lattice has been achieved through slow re-crystallization process under wet-chemical conditions followed by annealing at high temperatures (300–1400 °C). The nanophosphors were characterized by using powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and spectrofluorometer techniques. XRD analysis reveals formation of pure cubic phase of Y 2 O 3 in samples annealed at 700 °C or above. Further, the XRD data was successfully used to retrieve the crystallite size and size distribution from powder samples using the FW((1/5)/(4/5))M method. Crystallite size (11–50 nm) extracted from XRD has been found to be consistent with AFM measurements. The PL emission spectra of nanophosphors show bright red emission at 612 nm due to hypersensitive electric dipole (ED) 5 D 0 – 7 F 2 transition of Eu 3+ ions in Y 2 O 3 lattice. Further, photoluminescence studies indicate that optimum value of the Eu 3+ to get best luminescence properties is 12 at%. Surface conjugations of these nanophosphors with water soluble dextran biomolecules have also been performed. Surface conjugated rare earth nanophosphors have great potential for bio-applications.

Undoped and (0.5–5 at%) molybdenum-doped TiO2 nanoparticles were synthesized by a simple and scalable wet chemical method. The as-synthesized materials were characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy, electron paramagnetic resistance (EPR), and ultraviolet-visible (UV-Vis) spectroscopy techniques. XRD studies showed the formation of crystalline anatase phase of undoped TiO2, whereas Mo-doped samples showed the formation of an amorphous phase. AFM studies showed the formation of spherical-shaped particles with a particle diameter of ∼23 nm in all samples. The photochromic behavior of these materials was studied by making their films in alkyd resin. Films of these materials showed a reversible photochromic color change from beige to brown on exposure to UV light. The coloration and bleaching process was recorded using UV-Vis diffuse reflectance spectroscopy. The maximum color change was observed in 2 at% Mo+6-doped nano-TiO2. The photochromic mech...

Hydrated tungsten oxide nanoparticles have been synthesized using a simple wet chemical method while varying the concentration of HCl. XRD studies show that the variation in HCl concentration from 1 M to 6 M in the reaction results into gradual change in crystal structure of hydrated WO3 from hexagonal (WO3·0.33H2O) to pure orthorhombic (WO3·H2O), through a series of samples with mixed phase of the two indifferent ratios. The similar variations in the degree of hydration and phase variations have also been observed from Raman, FTIR and TGA studies. The average crystallite size of the hydrated WO3 particles was estimated to be ∼26 nm from XRD line broadening and AFM studies showed the formation of spherical shaped particles for all the samples. The photochromic studies were carried out on the composite films of these materials in the polymeric matrix of polyvinyl alcohol (PVA) while exposing to UV light. The composite films show interesting variations in the photochromic behavior depending on the crystal structure of hydrated WO3 filler. The photochromic behavior has been explained on the basis of EPR spectra of hydrated WO3.