Magnetodielectric composite with ferrite inclusions as substrates for microstrip patch antennas at microwave frequencies

A study has been conducted to estimate the complex permittivity and permeability along with magnetic characterization of different volume fractions of magnetodielectric composites with cobalt ferrite nano inclusions. Using an in touch superstrate technique dielectric properties are estimated. Cavity perturbation technique is used to study the complex permeability of the samples. 4πM_s value and coercivity is measured using vibrating sample magnetometry. Structural and surface morphologies on the composite samples are conducted to determine the size and homogeneous distribution of nano inclusions. The average grain size of cobalt ferrite nanoparticles is found to be ～10 nm. The real part of permittivity and permeability of the samples varies from ～1–2.905 to ～1.01–1.05 with increase in inclusion content from 1% VF to 5% VF, respectively. The tan δ of permittivity and imaginary part of permeability is found to be of the order of ～10^?3 and ～10^?1 respectively. Verification of these composites as potential substrates for microstrip patch antenna is carried out by fabricating simple rectangular patch at 9.5 GHz using transmission line model. Rectangular patch is designed on 5% VF composite system. The return loss for the composite system was found to be ～?19.451 dB which is comparable with that designed on standard glass epoxy substrate (?_r = 4.5).     

Synthesis and biological characterization of low-calorie Schisandra chinensis syrup

Food Science and Biotechnology - Schisandra chinensis (Omija) is a well-known medicinal plant in East Asia. In this study, Omija oligosaccharide syrup was prepared from sucrose with Omija fruit...     

In situ investigation of phosphonate retarder interaction in oil well cements at elevated temperature and pressure conditions

The effect of a high-performance retarding additive in oil well cements was investigated under elevated temperature (165°C) and pressure (1000 psi) conditions via in situ synchrotron-based X-ray diffraction (XRD) and quasielastic neutron scattering (QENS) techniques. Under these temperature and pressure conditions, crystalline calcium silicate hydrates (C–S–H) are formed through the cement hydration process. From in situ XRD experiments, the retardation effect was observed by a change in the rate of the appearance of 11 Å tobermorites as well as a change in the rate of the α-C₂SH generation and depletion. QENS analysis revealed that the retardation effect was related to the non-conversion of free water to chemical and constrained water components. A high presence of free water components was attributed to a decrease in 11 Å tobermorites along with slower consumption of the quartz and portlandite phases. Furthermore, QENS results infer that the water molecules experienced confinement in the restricted pore spaces. The retarder inhibited this initial water confinement by slowing the bulk diffusion of free water in the confined region.     

NSGA-II with ENLU inspired clustering for wireless sensor networks

Wireless Networks - Wireless sensor networks (WSNs) have a large number of existing applications and is continuously increasing. Thus it is envisioned that WSN will become an integral part of our...     

A Novel Self-Aligned Dopingless Symmetric Tunnel Field Effect Transistor (DL-STFET): A Process Variations Tolerant Design

Silicon - This work reports a novel device structure, dopingless heterojunction symmetric tunnel field effect transistor (DL-STFET), based on the work-function engineering. For realizing dopingless...     

Gelatin and amylopectin-based phase-separated hydrogels: An in-depth analysis of the swelling,mechanical, electrical and drug release properties

The current study delineates the development of gelatin–amylopectin-based phase-separated hydrogels for drug delivery applications. Gelatin and amylopectin were used as the representative protein and polysaccharide phases, respectively. The hydrogels were prepared by adding different proportions of amylopectin to gelatin solutions and subsequently cross-linking the mixture using glutaraldehyde. Microscopic analysis showed formation of phase-separated hydrogels. Secondary structure of gelatin was conserved within the hydrogels. The presence of amylopectin drastically reduced the rate of water absorption by the hydrogels. Viscoelastic analysis using stress relaxation study suggested an increase in the viscous component of the hydrogels with the increase in the amylopectin content. After incorporating amylopectin within the gelatin hydrogel, even though the bulk resistance remained unaltered, there was a corresponding variation in the capacitive elements of the equivalent electrical models. The release of the drug from the hydrogels was diffusion mediated. Suitable mathematical models were used for the analysis of the swelling (Peleg’s model), viscoelastic (Weichert model), electrical (RQQ model) and drug release (Korsmeyer–Peppas and Peppas–Sahlin models) properties. The drug retained its antimicrobial activity within the hydrogels. An analysis of the results suggested that the developed hydrogels may be explored as matrices for controlled drug delivery applications.     

An Efficient Compressive Sensing Routing Scheme for Internet of Things Based Wireless Sensor Networks

Wireless Personal Communications - Internet of Things (IoT) integrates diverse types of sensors, mobiles and other technologies to physical world and IoT technology is used in a wide range of...     

Phage Display to Identify Nedd8‐Mimicking Peptides as Inhibitors of the Nedd8 Transfer Cascade

The Nedd8 activating enzyme (NAE) launches the transfer of the ubiquitin‐like protein Nedd8 through an enzymatic cascade to covalently modify a diverse array of proteins, thus regulating their biological functions in the cell. The C‐terminal peptide of Nedd8 extends deeply into the active site of NAE and plays an important role in the specific recognition of Nedd8 by NAE. We used phage display to profile C‐terminal mutant sequences of Nedd8 that could be recognized by NAE for the activation reaction. We found that NAE can accommodate diverse changes in the Nedd8 C‐terminal sequence (⁷¹LALRGG⁷⁶), including Arg and Ile replacing Leu71, Leu, Ser, and Gln replacing Ala72, and substitutions by bulky aromatic residues at positions 73 and 74. We also observed that short peptides corresponding to the C‐terminal sequences of the Nedd8 variants can be activated by NAE to form peptide～NAE thioester conjugates. Once NAE is covalently loaded with these Nedd8‐mimicking peptides, it can no longer activate full‐length Nedd8 for transfer to the neddylation targets, such as the cullin subunits of cullin‐RING E3 ubiquitin ligases (CRLs). We have thus developed a new method to inhibit protein neddylation by Nedd8‐mimicking peptides.     

Study of oil sorption behavior of filled and structured fiber assemblies made from polypropylene, kapok and milkweed fibers

This article reports on oil sorption behavior of fiber assemblies made up of single natural and synthetic fibers as well as blend of natural and synthetic fibers when tested with high density oil and diesel oil. A series of filled fiber assemblies were prepared from 100% polypropylene, kapok, and milkweed fibers and another series of bonded structured fiber assemblies were prepared from a 70/30 blend of kapok and polypropylene fibers and a 70/30 blend of milkweed and polypropylene fibers. It was observed that the porosity of the fiber assemblies played a very important role in determining its oil sorption capacity. The polypropylene fiber assembly exhibited the highest sorption capacity (g/g) followed by the kapok and milkweed fiber assemblies at porosity <0.98. At higher porosities (above 0.98), polypropylene filled fiber assembly has poor sorption capacity due to large sized inter fiber pore. The kapok and milkweed fibers have intra fiber porosities of 0.81 and 0.83, respectively. All the fiber assemblies showed higher oil sorption capacity with the high density oil as compared to the diesel oil. As the kapok and milkweed fiber have low cellulose content, hence their slow degradation is an advantage in fresh and marine water applications. The good sorption capacity of kapok and milkweed fiber assemblies along with their bio-degradable nature offer great scope for structuring them into fiber assemblies with large porosity and uniform pores to have efficient oil sorbents.