Reconfigurable bow tie‐based filtering antenna for cognitive radio applications

This article presents the design and implementation of an 88 × 85 mm reconfigurable filtering bow‐tie antenna with four operating states. Two PIN diodes are deployed to reconfigure the transmission zeros to realize ultra‐wide band (UWB), 3.5/5.5 GHz with independent switching. This switching prevents the interference of the primary user into the secondary user thereby making the filtenna suitable for cognitive radio applications. The proposed filtenna consists of a UWB bow‐tie antenna integrated with a band‐pass filter with reconfigurable property enabled using two PIN diodes. The prototype‐filtering antenna is fabricated and the simulated results are validated using measurements. The presented results show that the antenna exhibits good impedance and radiation characteristics.     

Polarization diversity enabled flexible directional UWB monopole antenna for WBAN communications

This article presents the design of an ultra‐wideband (UWB) quasi‐circular monopole antenna with directional characteristics for use in wireless body area network (WBAN) applications. The proposed antenna has hybrid geometry and it is constructed using a semicircular and square patch on a very thin substrate of thickness 0.2 mm. The antenna has a compact geometry with a footprint of 30 × 20 mm. The proposed antenna covers 3.1 to 10.6 GHz with a measured peak gain of 5.37 dBi at 6 GHz. The proximity effect of the human body is resolved by incorporating the reflector behind the antenna. The antenna with reflector provides a directional pattern with a measured peak gain of 8.84 dBi at 6 GHz. Further to improve the link reliability between the sensor and the cluster head in WBAN, polarization diversity technique is adopted and the performance metrics are evaluated. The proposed flexible antenna simultaneously offers large gain and high impedance bandwidth. The prototype antenna is fabricated and the simulation results are validated using experimental measurements. The measurement results are in good agreement with the simulation results.     

RADL: a resource and deadline-aware dynamic load-balancer for cloud tasks

The Journal of Supercomputing - Cloud service providers acquire the computing resources and allocate them to their clients. To effectively utilize the resources and achieve higher user...     

PSO-RDAL: particle swarm optimization-based resource- and deadline-aware dynamic load balancer for deadline constrained cloud tasks

The Journal of Supercomputing - Cloud computing is an Internet-provisioned computing paradigm that provides scalable resources for the execution of the end user’s tasks. The cloud users lease...     

Effect of Surfactants and Temperature on Adsorption Behavior of Metal Ions on Organic–Inorganic Hybrid Exchanger,Acrylamide Aluminum Tungstate

The adsorption behavior of a thermally and chemically stable hybrid ion-exchange material, acrylamide aluminum tungstate was explored in cationic (CTAB) and anionic (SDS) surfactants and acidic solvents. Critical micellar concentration (CMC) appears to be an important parameter in determining the adsorption behavior of metal ions. Equilibration time and temperature studies on the distribution coefficient of metal ions were studied. On the basis of the distribution coefficient, this material was successfully used for quantitative separations of some binary synthetic mixtures of metal ions by the column method. Hg(II) ion was selectively determined quantitatively in synthetic mixture. The material appears to be promising for separating toxic metal ions in a real matrix (industrial effluents and waste water) and can be utilized as a packing material in HPLC and GC columns for faster and more efficient separation.

Germline POT1 Deregulation Can Predispose to Myeloid Malignancies in Childhood

While the shelterin complex guards and coordinates the mechanism of telomere regulation, deregulation of this process is tightly linked to malignant transformation and cancer. Here, we present the novel finding of a germline stop-gain variant (p.Q199*) in the shelterin complex gene POT1, which was identified in a child with acute myeloid leukemia. We show that the cells overexpressing the mutated POT1 display increased DNA damage and chromosomal instabilities compared to the wildtype counterpart. Protein and mRNA expression analyses in the primary patient cells further confirm that, physiologically, the variant leads to a nonfunctional POT1 allele in the patient. Subsequent telomere length measurements in the primary cells carrying heterozygous POT1 p.Q199* as well as POT1 knockdown AML cells revealed telomeric elongation as the main functional effect. These results show a connection between POT1 p.Q199* and telomeric dysregulation and highlight POT1 germline deficiency as a predisposition to myeloid malignancies in childhood.     

Effects of delamination in drilling glass/polyester composite

Considering failures during machinery processes such as drilling, a precautionary analysis involving delamination and the corresponding dissipated energy is required, especially for composite structures. In this context, because of the complexity of both the analysis procedure and experimental test setup, most studies prefer to represent mode I and III interlaminar crack propagation instead of that involving mode II. Therefore, in this study, the effect of mode II delamination and corresponding interlaminar crack propagation was considered during the drilling process of multilayered glass/polyester composites using both numerical and experimental approaches. In the experimental procedure, the mechanical properties of the glass/polyester specimens were obtained according to ASTM D3039. In addition, the interlaminar mixed-mode (I/II) loadings were determined using an ARCAN test fixture so that the fracture toughness of glass/polyester could then be identified. The mode II critical strain energy release rate (CSERR) was then obtained using an experimental test performed using an ARCAN fixture and the virtual crack closure technique (VCCT). It was determined that the numerical approach was in accordance with the experiments, and more than 95% of crack propagation could be attributed to mode II compared to the two other modes.     

Monitoring of genetically modified food and feed in the Tunisian market using qualitative and quantitative real-time PCR

Genetically modified organisms (GMO) invade more and more the agricultural production in the world. Although there are no legislations on GM labeling and cultivation of GM crops in Tunisia, the present study aims to check the status of GMO in Tunisian market using qualitative and quantitative real time-PCR (QRT-PCR). Three-hundred-sixty five samples were collected and different DNA extraction methods were adapted and optimized. Specific primers targeting 35S promoter from Cauliflower mosaic virus (CaMV) and nopaline synthase terminator from Agrobacterium tumefaciens (At) were used for the detection of the GMO insert and Taxon specific primers for the detection of plant species. Validated Taqman® probes (EU-RL) targeting event specific regions of the maize events MON810, Bt11, and the soybean event RRS were used for the quantification studies. Seven food and feed products showed different amounts of RRS (1.9%), MON810 (2.1%), and Bt11 (1.6%). The results demonstrate for the first time the presence of GMO in Tunisian markets reinforcing the need for the development of accurate quantitative methods in routine analyses.     

Occurrence and characterization of Escherichia coli O157 and other serotypes in raw meat products in Morocco

In this study, 100 raw meat samples were collected from 15 local Moroccan butcheries in five different areas of the city of Rabat during a period of 4 months. Overall, 7 of 15 butcheries from three areas of the city yielded strains of Escherichia coli O157. Single isolates from 9 (9%) of 100 raw meat samples were biochemically and serologically confirmed as E. coli O157. Using molecular techniques, two strains were positive for the Shiga toxin, with two additional strains containing an attaching-effacing gene. All potentially virulent serotypes isolated from these meat samples showed distinct pulsed-field gel electrophoresis profiles. Based on antibiotic susceptibility testing, more than 70% of the isolates were resistant to ampicillin and clavulanic acid-amoxicillin. Moreover, one strain was resistant to more than three antibiotics. Our study represents the first survey of E. coli O157 and related serotypes in raw meat products in Morocco.     

Cobalt–Iron nanoparticles encapsulated in mesoporous carbon nanosheets: A one-pot synthesis of highly stable electrocatalysts for overall water splitting

Advancement of cost-effective, highly efficient and non-noble metal-based bifunctional electrocatalysts is considered an attractive approach to overcome the energy defect and environmental pollution challenges. Herein, this study presents a simple one-pot approach to synthesize cobalt-Iron nanoparticles encapsulated in mesoporous carbon nanosheets (Co₃Fe₇@CNSs) by the pyrolysis method. The Co₃Fe₇@CNSs-750/4h electrocatalyst exhibits a notable performance, low overpotential of 181 and 301 mV at a current density of 10 mA cm^?2 and small Tafel slope of 124.8 and 38.59 mV dec^?1, large active surface area 18.20 and 21.18 mF cm^?2, and low charge transfer resistance 4.92 and 9.42 Ω for hydrogen and oxygen evolution reactions, respectively, in 1.0 M KOH. Overall water splitting, with the set-up of two-electrode cells acquires the 10 mA cm^?2 of current density at 1.610 V in 1.0 M KOH. The combined structure of cobalt-iron nanoparticles encapsulated in carbon nanosheets; it could enhance the surface area and, provide more active sites that improve the overall catalytic activity. Not only this but also the synergistic effect due to different temperature treatments which significantly influenced the structural formation. However, the major involvement of this study is concerned with the production of economical non-noble metal-based electrocatalysts at an industrial scale for renewable energy to sustainability.