Design and construct of a new detector for gas chromatography based on continuous negative corona discharge

In this work, a new detector was designed and constructed based on negative corona discharge. This detector can be used separately or as a detector in gas chromatography. The detector and chromatographic variables including cell temperature, gas flow rates, voltage between the two electrodes, and column temperature were optimized. Chloroform was used as a test compound to evaluate the performance of the detector. The detection limit of chloroform was obtained 0.78 ng∕ml and its dynamic range was over the range of 2-840 ng∕ml. The relative standard detection was about 6% for the limit of quantification. This detector is able to be used as an alternative for analysis of compounds containing electronegative elements.     

Synthesis and Characterization of Superparamagnetic NiBaO<Subscript>2</Subscript> Nano-Oxide Using Novel Precursor Complex [Ba(H<Subscript>2</Subscript>O)<Subscript>8</Subscript>][Ni(dipic)<Subscript>2</Subscript>]

In this paper, for the first time, synthesis of [Ba(H₂O)₈][Ni(dipic)₂] complex and preparation of NiBaO₂ nano-oxide are reported through thermal decomposition under surfactant free condition. This novel complex was characterized by Fourier transform infrared spectroscopy (FT-IR), ultra violet–visible spectroscopy, conductivity measurement and elemental analysis. Formation of novel nanoparticles was supported by FT-IR and energy-dispersive X-ray spectroscopy and the orthorhombic structure of nanocrystals was confirmed by powder X-ray diffraction analysis. In addition, size distribution as well as uniform morphology of prepared nano-oxide were recorded by dynamic light scattering analysis and field-emission scanning electron microscopy, respectively. Magnetic features measured by vibrating sample magnetometer, illustrate superparamagnetic behavior of the oxide.     

ERES: an extended regular expression signature for polymorphic worm detection

Journal of Computer Virology and Hacking Techniques - The quick spreading of modern sophisticated polymorphic worms poses a serious threat to the internet security. So far, several signature...     

Iron oxide/gold nanoparticles‐decorated reduced graphene oxide nanohybrid as the thermo‐radiotherapy agent

The main focus of the current study is the fabrication of a multifunctional nanohybrid based on graphene oxide (GO)/iron oxide/gold nanoparticles (NPs) as the combinatorial cancer treatment agent. Gold and iron oxide NPs formed on the GONPs via the in situ synthesis approach. The characterisations showed that gold and iron oxide NPs formed onto the GO. Cell toxicity assessment revealed that the fabricated nanohybrid exhibited negligible toxicity against MCF‐7 cells in low doses (<50 ppm). Temperature measurement showed a time and dose‐dependent heat elevation under the interaction of the nanohybrid with the radio frequency (RF) wave. The highest temperature was recorded using 200 ppm concentration nanohybrid during 40 min exposure. The combinatorial treatments demonstrated that the maximum cell death (average of 53%) was induced with the combination of the nanohybrid with RF waves and radiotherapy (RT). The mechanistic study using the flow cytometry technique illustrated that early apoptosis was the main underlying cell death. Moreover, the dose enhancement factor of 1.63 and 2.63 were obtained from RT and RF, respectively. To sum up, the authors’ findings indicated that the prepared nanohybrid could be considered as multifunctional and combinatorial cancer therapy agents.Inspec keywords: radiation therapy, toxicology, gold, biomedical materials, nanofabrication, nanoparticles, iron compounds, cancer, nanomedicine, cellular biophysics, tumours, graphene compounds, biothermicsOther keywords: graphene oxide nanohybrid, combinatorial cancer treatment agent, cell toxicity assessment, MCF‐7 cells, dose‐dependent heat elevation, multifunctional cancer therapy agents, thermoradiotherapy agent, graphene oxide‐iron oxide‐gold nanoparticles, temperature measurement, radiofrequency wave, flow cytometry, time 40.0 min, CO‐FeO‐Au     

An Investigation of Y<Subscript>3</Subscript>Ba<Subscript>5</Subscript>Cu<Subscript>8</Subscript>O<Subscript>18</Subscript> Doping with Ag Nanoparticles and Its Application as Superconductor

Y₃Ba₅Cu₈O₁₈ superconductors were prepared through a standard solid-state reaction and the structural properties of the samples were studied through XRD and the Rietveld refinement method. The effect of silver nanoparticles doping on the Y₃Ba₅Cu₈O₁₈ superconductors was studied as well. It is known that the size of nanoparticles is increased during aging. Therefore, two batches of samples with 1 and 2 wt% of Ag nanoparticles and the size range of 30, 200, 500, 700, 800, and 1000 nm were prepared. After preparing the samples and observing the Meissner effect, the crystallography, critical current density, critical temperature, magnetic susceptibility, SEM, and EDX experiments of the samples were carried out. The results of the critical current density measurements showed that the sample with 2 wt% Ag nanoparticles and the size of 700 nm has the maximum current density. In both batches of samples, increasing the nanoparticle size to 700 nm led to an increase in the critical current density. The crystallography studies showed that silver nanoparticles do not insert into the superconductor’s frame. Actually, they are placed in the samples as a distinct phase.     

The effect of hydrolysed tragacanth gum and inulin on the probiotic viability and quality characteristics of low‐fat yoghurt

This study investigates the effect of supplementation of tragacanth gum (GT, 0.05% w/v), low molecular weight gum tragacanth (LMWGT, 0.5% w/v) and inulin (0.5% w/v) on the viability of Bifidobacterium bifidum and the quality parameters of low‐fat yoghurt during a three‐week storage period. The count of probiotics was found to be 7.8 log cfu/g in inulin, and LMWGT enriched yoghurts at the end of the storage period. The minimum water holding capacity and the maximum syneresis values were also obtained in the low‐fat yoghurt enriched with GT throughout the storage time. The samples containing inulin and LMWGT revealed sensory attributes that were judged superior compared to those in GT.     

A reliable and efficient micro-protocol for data transmission over an RTP-based covert channel

Multimedia Systems - As the VoIP steganographic methods provide a low capacity covert channel for data transmission, an efficient and real-time data transmission protocol over this channel is...     

A bandwidth-efficient and fair CSMA/TDMA based multichannel MAC scheme for V2V communications

Designing QoS-aware medium access control (MAC) scheme is a challenging issue in vehicular ad hoc networks. Proportional fairness and bandwidth utilization are among the significant requirements that should be taken into account by a MAC scheme. In this paper, a bandwidth-efficient and fair multichannel MAC protocol is proposed to address these two requirements, specifically in vehicle-to-vehicle communications. The proposed scheme is based on clustering of vehicles and exploits time division multiple access (TDMA) method alongside the carrier sense multiple access with collision avoidance mechanism to allocate DSRC-based resources in a different manner from IEEE 802.11p/IEEE 1609.4 protocols. It divides each channel into aligned dynamic-sized time frames. In each time frame, in a fully TDMA-based period, transmission opportunities are assigned to vehicles letting them have dedicated transmissions on the service and control channels. The maximum number of transmission opportunities per each frame is determined by the cluster head (CH) based on a defined optimization problem which aims at maximizing both proportional fairness and bandwidth utilization. Furthermore, the bandwidth utilization is assumed to be enhanced more through reallocation of unused transmission opportunities in each time frame, using a proposed reallocation algorithm. The proposed MAC protocol is treated as a lightweight scheme such that various types of unicast, multicast and broadcast communications are possible within the cluster without involving the CH. Evaluation results show that the proposed scheme has more than 90 % achievement in terms of proportional fairness and bandwidth utilization simultaneously, and in this case, has a considerable superiority over TC-MAC. In addition, using the proposed scheme, the satisfaction level of vehicles is preserved appropriately.     

A survey on applications of IEEE 802.21 Media Independent Handover framework in next generation wireless networks

Integration of various wireless access technologies is one of the major concerns in recent wireless systems in which multi-technology mobile devices are provided to users to roam between different access networks. Being an essential part in heterogeneous wireless systems, vertical handover is more complex than conventional horizontal handover. As IEEE 802.21 Media Independent Handover (MIH) is the standard addressing a uniform and media-independent framework for seamless handover between different access technologies, many works have been carried out in the literature to employ MIH services in handover management This paper presents a comprehensive survey of the proposed mobility management mechanisms that are using this framework. As a comparative view, the paper categorizes the efforts according to the layer of mobility management and evaluates some of the representative methods discussing about their advantages and disadvantages The paper also looks into recent handover decision and interface management methods that are exploiting MIH Moreover, the extensions and the amendments proposed on MIH are overviewed.