Conjugated Polymer Nanoparticle–Graphene Oxide Charge‐Transfer Complexes

The game‐changing role of graphene oxide (GO) in tuning the excitonic behavior of conjugated polymer nanoparticles is described for the first time. This is demonstrated by using poly(3‐hexylthiophene) (P3HT) as a benchmark conjugated polymer and employing an in situ reprecipitation approach resulting in P3HT nanoparticles (P3HT_NPs) with sizes of 50–100 nm in intimate contact with GO. During the self‐assembly process, GO changes the crystalline packing of P3HT chains in the forming P3HT_NPs from H to H/J aggregates exhibiting exciton coupling constants as low as 2 meV, indicating favorable charge separation along the P3HT chains. Concomitantly, π–π interface interactions between the P3HT_NPs and GO sheets are established resulting in the creation of P3HT_NPs–GO charge‐transfer complexes whose energy bandgaps are lowered by up to 0.5 eV. Moreover, their optoelectronic properties, preestablished in the liquid phase, are retained when processed into thin films from the stable aqueous dispersions, thus eliminating the critical dependency on external processing parameters. These results can be transferred to other types of conjugated polymers. Combined with the possibility of employing water based “green” processing technologies, charge‐transfer complexes of conjugated polymer nanoparticles and GO open new pathways for the fabrication of improved optoelectronic thin film devices.     

Health care service delivery based on the Internet of things: A systematic and comprehensive study

Today, the Internet of Things (IoT) becomes a heterogeneous and highly distributed structure which can respond to the daily needs of people and different organizations. With the fast development of IT‐based technologies such as IoT and cloud computing, low‐cost health services and their support, efficient supervision of the centralized management, and monitoring of public health can be realized. Therefore, there has been increasing attention in the integration of IoT and health care both in academic and the business world. However, while the health care service industry fully holds the welfares of information systems for its personnel and patients, there is a need for an improved understanding of the issues and opportunities related to IoT‐based health care systems. But, as far as we know, the detailed review and deep discussion in this field are very rare. Hence, in this paper, we presented a literature review on the IoT‐based health care services from papers published until 2018. Moreover, the drawbacks and benefits of the reviewed mechanisms have been discussed, and the main challenges of these mechanisms are highlighted for developing more efficient IoT techniques over health care services in the future. The results of this paper will be valuable for both practitioners and academicians, and it can provide visions into future research areas in this domain. By providing comparative information and analyzing the current developments in this area, this paper will directly support academics and working professionals for better knowing the progress in IoT mechanisms. As a general result, we found that IoT could help the governments to improve health services in society and commercial interactions.     

A multi-agent based approach for change management in manufacturing enterprises

Change management becomes an unavoidable necessity for manufacturing enterprises. Since change in business processes carries significant impact on the performance of manufacturing companies, a change management model is definitely required to remain competitive. Moreover, utilizing agent based systems will provide computational provision and integrity to manage and measure the capabilities to follow the change in a progressive approach by employing the cooperation and collaboration properties of various agents helping for retrieval of the required information in a rapid way. Therefore, in this paper, a multi-agent based change management model is proposed to handle the changes in manufacturing enterprises. The model is validated through a case study done to measure the performance of change management capabilities in a manufacturing company. A sensitivity analysis on the results of this case study is also conducted to reveal the system reactivity to various parameters.     

Investigation of microwave power limiter for Industrial Scientific Medical band (ISM) applications

In this paper, a new design of microstrip power limiter which is based on microstrip technology and zero bias Schottky diode is introduced. In this context, the FR‐4 substrate that was characterized by dielectric permittivity (4.4), dielectric thickness (1.6 mm), and the HSMS 286k Schottky diode is used to design the proposed power limiter. The planar resonators are designed, optimized, and simulated with the shunting of the HSMS 286k diodes by using Schematic solver integrated in ADS from Agilent Technologies. The simulation results are significant in terms of high impedance matching, strong insertion of the low power, and good limitation ratio of the high power. The proposed power limiter is fabricated and tested in the measurement part. It is observed that the results are in agreement with the numerical analysis in terms of matching, isolation, and power limitation. The achieved microwave power limiter offers simple construction, small size (44 × 40 mm²), wide bandwidth, and good limitation ratio less than 10 dBm when the input power reaches 30 dBm.     

Wide band fractal‐based perfect energy absorber and power harvester

In this article, a novel wide band polarization and incident angle independent metamaterial absorber (MA) and energy harvesting applications which operates at C (4GHz‐8 GHz) and X (8GHz‐12 GHz) is proposed. The unit‐cell of the proposed structure based on fractal circle loop. Four lumped resistors are mounted the structure to obtain a broad band absorption characteristics. Resistors increase the absorption characteristic of proposed MA significantly at mentioned frequency ranges. In addition, under favor of the resistors proposed MA can convert absorbed energy from incident wave to appearing power.     

Densification and characterization of rapid carbothermal synthesized boron carbide

Submicrometer boron carbide powders were synthesized using rapid carbothermal reduction (RCR) method. Synthesized boron carbide powders had smaller particle size, lower free carbon, and high density of twins compared to commercial samples. Powders were sintered using spark plasma sintering at different temperatures and dwell times to compare sintering behavior. Synthesized boron carbide powders reached >99% TD at lower temperature and shorter dwell times compared to commercial powders. Improved microhardness observed in the densified RCR samples was likely caused by the combination of higher purity, better stoichiometry control, finer grain size, and a higher density of twin boundaries.     

Determination of FA composition and total trans FA of Turkish margarines by capillary GLC

In this research, FA composition and total trans FA contents of 16 different brands of margarine (8 hard-type and 8 soft-type) sold in Turkey were determined by capillary GLC method. According to the results, the contents of saturated FA, monounsaturated FA, and PUFA were within the ranges of 23.9–32.3, 44.0–61.9, and 14.2–24.1%, respectively, in hard-type margarines, and 27.0–39.9, 21.0–40.9, and 32.0–53.7%, respectively, in soft-type margarines. Hard-type margarines contained total trans FA concentrations of 20.1–34.3%, whereas soft-type margarines contained less than 8.9% total trans FA. C_18∶1 trans acid content was within the range of 18.5–29.8% in hard-type margarines, and it was significantly higher than the range in soft margarines (0.7–8.1%). C_18∶1 trans acid was the major trans FA in all margarines, and C_18∶3 trans acid concentrations were less than 0.2%.     

Unbalanced states violates RFID privacy

Designing privacy preserving authentication protocols for massively deployed Radio Frequency IDentification (RFID) systems is a real world challenge that have drawn significant attention from RFID community. This interest yields considerable amount of proposals targeting to overcome the main bottleneck (i.e. the exhaustive search over the list of all tag entries) which appears in the back-end database for large-scale RFID tag deployments. A class of these proposals contains RFID protocols where the server authenticates the tag in a negligible constant/sub-linear time for a more frequent normal state and needs a linear search in a rare abnormal states. In this study, however, we show that such protocols having unbalanced states are subject to side-channel attacks and do not preserve the RFID privacy. To illustrate this brutal security flaw, we conduct our analysis on different RFID protocols.